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Sample records for thalamus

  1. Acupuncture for refractory epilepsy: role of thalamus.

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    Chen, Shuping; Wang, Shubin; Rong, Peijing; Liu, Junling; Zhang, Hongqi; Zhang, Jianliang

    2014-01-01

    Neurostimulation procedures like vagus nerve stimulation (VNS) and deep brain stimulation have been used to treat refractory epilepsy and other neurological disorders. While holding promise, they are invasive interventions with serious complications and adverse effects. Moreover, their efficacies are modest with less seizure free. Acupuncture is a simple, safe, and effective traditional healing modality for a wide range of diseases including pain and epilepsy. Thalamus takes critical role in sensory transmission and is highly involved in epilepsy genesis particularly the absence epilepsy. Considering thalamus serves as a convergent structure for both acupuncture and VNS and the thalamic neuronal activities can be modulated by acupuncture, we propose that acupuncture could be a promising therapy or at least a screening tool to select suitable candidates for those invasive modalities in the management of refractory epilepsy.

  2. Acupuncture for Refractory Epilepsy: Role of Thalamus

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    Shuping Chen

    2014-01-01

    Full Text Available Neurostimulation procedures like vagus nerve stimulation (VNS and deep brain stimulation have been used to treat refractory epilepsy and other neurological disorders. While holding promise, they are invasive interventions with serious complications and adverse effects. Moreover, their efficacies are modest with less seizure free. Acupuncture is a simple, safe, and effective traditional healing modality for a wide range of diseases including pain and epilepsy. Thalamus takes critical role in sensory transmission and is highly involved in epilepsy genesis particularly the absence epilepsy. Considering thalamus serves as a convergent structure for both acupuncture and VNS and the thalamic neuronal activities can be modulated by acupuncture, we propose that acupuncture could be a promising therapy or at least a screening tool to select suitable candidates for those invasive modalities in the management of refractory epilepsy.

  3. Acupuncture for Refractory Epilepsy: Role of Thalamus

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    Chen, Shuping; Wang, Shubin; Rong, Peijing; Liu, Junling; Zhang, Hongqi; Zhang, Jianliang

    2014-01-01

    Neurostimulation procedures like vagus nerve stimulation (VNS) and deep brain stimulation have been used to treat refractory epilepsy and other neurological disorders. While holding promise, they are invasive interventions with serious complications and adverse effects. Moreover, their efficacies are modest with less seizure free. Acupuncture is a simple, safe, and effective traditional healing modality for a wide range of diseases including pain and epilepsy. Thalamus takes critical role in ...

  4. What does the mediodorsal thalamus do?

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    Anna S Mitchell

    2013-08-01

    Full Text Available Dense amnesia can result from damage to the medial diencephalon in humans and in animals. In humans this damage is diffuse and can include the mediodorsal nuclei of the thalamus. In animal models, lesion studies have confirmed the mediodorsal thalamus (MD has a role in memory and other cognitive tasks, although the extent of deficits is mixed. Anatomical tracing studies confirm at least three different subgroupings of the MD: medial, central and lateral, each differentially interconnected to the prefrontal cortex. Moreover, these subgroupings of the MD also receive differing inputs from other brain structures, including the basal ganglia thus the MD subgroupings form key nodes in interconnected frontal-striatal-thalamic neural circuits, integrating critical information within the prefrontal cortex. We will provide a review of data collected from non-human primates and rodents after selective brain injury to the whole of the MD as well as these subgroupings to highlight the extent of deficits in various cognitive tasks. This research highlights the neural basis of memory and cognitive deficits associated with the subgroupings of the MD and their interconnected neural networks. The evidence shows that the MD plays a critical role in many varied cognitive processes. In addition, the MD is actively processing information and integrating it across these neural circuits for successful cognition. Having established that the MD is critical for memory and cognition, further research is required to understand how the MD specifically influences these cognitive processing carried out by the brain.

  5. The GABRB1 gene is associated with thalamus volume and modulates the association between thalamus volume and intelligence.

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    Zhu, Bi; Chen, Chuansheng; Xue, Gui; Lei, Xuemei; Li, Jin; Moyzis, Robert K; Dong, Qi; Lin, Chongde

    2014-11-15

    The GABRB1 gene encodes the beta 1 subunit of the gamma-aminobutyric acid A receptor (GABA A receptor), which is responsible for mediating inhibitory neurotransmission in the thalamus. Potential relationships between the GABRB1 gene, thalamus volume, and intelligence have been suggested by previous clinical studies, but have not been directly examined among nonclinical samples. The current study collected structural MRI, genetic, and behavioral data from 316 healthy Chinese adults (including 187 females and 129 males), and examined associations between GABRB1 variants, thalamus volume, and intelligence (measured by the Wechsler Adult Intelligence Scale Revised). After controlling for intracranial volume, sex, and age, GABRB1 genetic polymorphism at the SNP rs7435958 had the strongest association with thalamus volume (p = 0.002 and 0.00008 for left and right thalamus volumes, respectively), with GG homozygotes having smaller bilateral thalamus volumes than the other genotypes. Furthermore, there were positive correlations between bilateral thalamus volumes and intelligence, especially for GABRB1 rs7435958 GG female homozygotes (r's = 0.31 and 0.29, p intelligence with left and right thalamus volumes, respectively). This study provides the first evidence for the involvement of the GABRB1 gene in the thalamus structure and their interactive effects on intelligence. Future studies of the thalamus-intelligence associations should consider genetic factors as potential moderators. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Thalamus lesions in chronic and acute seizure disorders

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    Tschampa, Henriette J.; Greschus, Susanne; Urbach, Horst [University of Bonn, Department of Radiology (Neuroradiology), Bonn (Germany); Sassen, Robert; Bien, Christian G. [University of Bonn, Department of Epileptology, Bonn (Germany)

    2011-04-15

    Transient signal changes in the pulvinar have been described following status epilepticus. However, we observed persistent thalamus changes after seizures. The purpose of this study was to characterize thalamus changes in patients with seizure disorders and to correlate imaging findings with clinical features. We searched among 5,500 magnetic resonance imaging (MRI) exams performed in patients with seizures and identified 43 patients. The MRI scans of these patients were reviewed and correlated with clinical data. We identified four patterns of thalamus lesions: (a) fluid attenuated inversion recovery-hyperintense pulvinar lesions (20 patients), as known from status epilepticus. Ten patients in this group had a status epilepticus. Among the remaining patients, three had frequent seizures and seven had sporadic seizures. Twelve patients had follow-up exams for a median of 11 months. The lesions had persisted in 11/12 cases in the last available exam and were reversible in one case only. In seven cases, cone-shaped thalamus atrophy resulted, (b) linear defects in the medial and anterior thalamus (five patients), accompanied by atrophy of the mamillary body and the fornix in patients with chronic epilepsy, (c) extensive bilateral thalamus lesions in two patients with a syndrome caused by mutation in the mitochondrial polymerase gamma, and (d) other thalamus lesions not associated with the seizure disorder (16 patients). The spectrum of thalamus lesions in patients with seizure disorders is wider than previously reported. Postictal pulvinar lesions can persist and may result in thalamic atrophy. Linear defects in the anterior thalamus are associated with limbic system atrophy. (orig.)

  7. Basal ganglia - thalamus and the crowning enigma

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    Marianela eGarcia-Munoz

    2015-11-01

    Full Text Available When Hubel (1982 referred to layer 1 of primary visual cortex as …a ‘crowning mystery’ to keep area-17 physiologists busy for years to come... he could have been talking about any cortical area. In the 80’s and 90’s there were no methods to examine this neuropile on the surface of the cortex: a tangled web of axons and dendrites from a variety of different places with unknown specificities and doubtful connections to the cortical output neurons some hundreds of microns below. Recently, three changes have made the crowning enigma less of an impossible mission: the clear presence of neurons in layer 1 (L1, the active conduction of voltage along apical dendrites and optogenetic methods that might allow us to look at one source of input at a time. For all of those reasons alone, it seems it is time to take seriously the function of L1. The functional properties of this layer will need to wait for more experiments but already L1 cells are GAD67 positive, i.e., inhibitory! They could reverse the sign of the thalamic glutamate (GLU input for the entire cortex. It is at least possible that in the near future normal activity of individual sources of L1 could be detected using genetic tools. We are at the outset of important times in the exploration of thalamic functions and perhaps the solution to the crowning enigma is within sight. Our review looks forward to that solution from the solid basis of the anatomy of the basal ganglia output to motor thalamus. We will focus on L1, its afferents, intrinsic neurons and its influence on responses of pyramidal neurons in layers 2/3 and 5. Since L1 is present in the whole cortex we will provide a general overview considering evidence mainly from the somatosensory cortex before focusing on motor cortex.

  8. Gain control in the visual thalamus during perception and cognition.

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    Saalmann, Yuri B; Kastner, Sabine

    2009-08-01

    The thalamus has traditionally been thought to passively relay sensory information to the cortex. By showing that responses in visual thalamus are modulated by perceptual and cognitive tasks, recent fMRI and physiology studies have helped revise this view. The modulatory input to the visual thalamus derives from functionally distinct cortical and subcortical feedback pathways. These pathways enable the lateral geniculate nucleus and pulvinar to regulate the information transmitted to cortical areas according to cognitive requirements. Emerging evidence suggests that such regulation involves changing the degree of synchrony between neurons as well as changing the magnitude of thalamic activity. These findings support a role for the thalamus that extends as far as contributing to the control of visual attention and awareness.

  9. Differential developmental strategies by Sonic hedgehog in thalamus and hypothalamus.

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    Zhang, Yuanfeng; Alvarez-Bolado, Gonzalo

    2016-09-01

    The traditional concept of diencephalon (thalamus plus hypothalamus) and with it the entire traditional subdivision of the developing neural tube are being challenged by novel insights obtained by mapping the expression of key developmental genes. A model in which the hypothalamus is placed in the most rostral portion of the neural tube, followed caudally by a diencephalon formed by prethalamus, thalamus and pretectum has been proposed. The adult thalamus and hypothalamus are quite unlike each other in connectivity and functions. Here we review work on the role of the secreted morphogen protein Sonic hedgehog (Shh) in the developing diencephalon and hypothalamic region to show how different these two regions are also from this point of view. Shh from the prechordal plate (PCP) induces and patterns the hypothalamus but there is no evidence that this role is fulfilled by a morphogen gradient. Later, the hypothalamic primordium itself expresses Shh and a large part of the hypothalamus belongs to the Shh lineage, including the ventral domains. Neural Shh is necessary to complete the specification (lateral hypothalamus), differentiation and growth of the hypothalamus. Although Gli2A is the major effector of Shh in this region, hypothalamic specification also depends on the suppression of Gli3R by Shh secreted by the PCP as well as the neuroepithelium. The thalamus is patterned by an Shh morphogen gradient originated in the ZLI following similar mechanisms to those in the spinal cord. The thalamus itself does not belong to the Shh lineage. Gli2A is necessary for appropriate growth and specification of the thalamic nuclei, to the exception of the medial and intralaminar groups (limbic-related), whose development depends on Gli3R. Beyond specification and patterning, the scarce data available about cell sorting and aggregation in these two regions shows key differences between them as well. In summary, not only expression patterns but also developmental mechanisms support

  10. Strategic infarcts of the thalamus in vascular dementia.

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    Szirmai, Imre; Vastagh, Ildikó; Szombathelyi, Eva; Kamondi, Anita

    2002-11-15

    Strategic infarcts or focal hemorrhages involving the paramedian nuclei of the thalamus may alter consciousness and produce complex neuropsychological symptoms such as impairment of memory, attention and motivation. Lesions disrupting the thalamo-prefrontal circuits lead to severe subcortical dementia. We analysed here the clinical, neuropsychological and neuroimaging data of 19 patients with cerebrovascular lesions in the thalamus. In six patients with bilateral paramedian infarcts, and in two with anterior thalamic infarcts, vascular dementia and severe personality changes developed. SPECT findings did not correlate with the neuropsychological symptoms. Transcortical sensory and motor aphasia was observed in four patients with thalamic hemorrhages and infarcts. In these patients SPECT detected hypoperfusion in adjacent cortical areas. Clinical symptoms and outcome of four patients are reported in detail. The clinico-morphological correlations of the thalamo-cortical circuits are reviewed and the possible causes of multiple cognitive and behavioural consequences of vascular thalamic lesions are discussed.

  11. Thalamus segmentation from MP2RAGE: a comparative study

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Næss-Schmidt, Erhard; Blicher, Jakob

    the Freesurfer pipeline, which is a high failure rate compared to studies running Freesurfer on conventional MPRAGE images [7]. All evaluated methods under-segments the thalamus, which may be desirable from a clinical point of view, if segmentation masks are used for characterizing the structure using e......Introduction: MPRAGE has become one of the most widely used MRI sequences to obtain T1-weighted anatomical images. However, at high static field strengths the increased inhomogeneity of B1 fields leads to high intensity variations across the image (bias field). Recently, it was suggested to use two...... methods may not work well with this new sequence. In this study we tested three different automatic methods for the important task of segmenting the thalamus from human brain MP2RAGE images. Methods: Twelve healthy control subjects (age range 19 – 38 years, two females) were scanned with a whole brain MP2...

  12. MRI of germinomas arising from the basal ganglia and thalamus

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    Kim, D.I.; Yoon, P.H.; Ryu, Y.H.; Jeon, P.; Hwang, G.J. [Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1998-08-01

    We reviewed the MRI findings of germinomas originating from the basal ganglia, thalamus or deep white matter in 13 patients with 14 germinomas, excluding those in the suprasellar or pineal regions. Ten cases were confirmed as germinomas by stereotaxic biopsy, three by partial and one by total removal of the tumour. Analysis was focussed on the location and the signal characteristic of the tumour, haemorrhage, cysts within the tumour and any other associated findings. Thirteen of the tumours were in the basal ganglia and one in the thalamus. Haemorrhage was observed in seven patients, while twelve showed multiple cysts. Associated ipsilateral cerebral hemiatrophy was seen in three patients. The signal intensity of the parenchymal germinomas was heterogeneous on T1- and T2-weighted images due to haemorrhage, cysts and solid portions. We also report the MRI findings of germinomas in an early stage in two patients. (orig.) With 5 figs., 1 tab., 17 refs.

  13. Characterization of progenitor domains in the developing mouse thalamus.

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    Vue, Tou Yia; Aaker, Joshua; Taniguchi, Aya; Kazemzadeh, Christina; Skidmore, Jennifer M; Martin, Donna M; Martin, James F; Treier, Mathias; Nakagawa, Yasushi

    2007-11-01

    To understand the molecular basis of the specification of thalamic nuclei, we analyzed the expression patterns of various transcription factors and defined progenitor cell populations in the embryonic mouse thalamus. We show that the basic helix-loop-helix (bHLH) transcription factor Olig3 is expressed in the entire thalamic ventricular zone and the zona limitans intrathalamica (ZLI). Next, we define two distinct progenitor domains within the thalamus, which we name pTH-R and pTH-C, located caudal to the ZLI. pTH-R is immediately caudal to the ZLI and expresses Nkx2.2, Mash1, and Olig3. pTH-C is caudal to pTH-R and expresses Ngn1, Ngn2, and Olig3. Short-term lineage analysis of Olig3-, Mash1-, Ngn1-, and Ngn2-expressing progenitor cells as well as tracing the Pitx2 cell lineage suggests that pTH-C is the only major source of thalamic nuclei containing neurons that project to the cerebral cortex, whereas pTH-R and ZLI are likely to produce distinct postmitotic populations outside of the cortex-projecting part of the thalamus. To determine if pTH-C is composed of subdomains, we characterized expression of the homeodomain protein Dbx1 and the bHLH protein Olig2. We show that Dbx1 is expressed in caudodorsal-high to rostroventral-low gradient within pTH-C. Analysis of heterozygous Dbx1(nlslacZ) knockin mice demonstrated that Dbx1-expressing progenitors preferentially give rise to caudodorsal thalamic nuclei. Olig2 is expressed in an opposite gradient within pTH-C to that of Dbx1. These results establish the molecular heterogeneity within the progenitor cells of the thalamus, and suggest that such heterogeneity contributes to the specification of thalamic nuclei. 2007 Wiley-Liss, Inc

  14. Unusual acute encephalitis involving the thalamus: imaging features

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    Kim, Sam Soo [Kangwon National University Hospital, Chuncheon (Korea, Republic of); Chang, Kee Hyun; Kim, Kyung Won; Han Moon Hee [Seoul National University College of Medicine, Seoul (Korea, Republic of); Park, Sung Ho; Nam, Hyun Woo [Seoul City Boramae Hospital, Seoul (Korea, Republic of); Choi, Kyu Ho [Kangnam St. Mary' s Hospital, Seoul (Korea, Republic of); Cho, Woo Ho [Sanggyo Paik Hospital, Seoul (Korea, Republic of)

    2001-06-01

    To describe the brain CT and MR imaging findings of unusual acute encephalitis involving the thalamus. We retrospectively reviewed the medical records and CT and/or MR imaging findings of six patients with acute encephalitis involving the thalamus. CT (n=6) and MR imaging (n=6) were performed during the acute and/or convalescent stage of the illness. Brain CT showed brain swelling (n=2), low attenuation of both thalami (n=1) or normal findings (n=3). Initial MR imaging indicated that in all patients the thalamus was involved either bilaterally (n=5) or unilaterally (n=1). Lesions were also present in the midbrain (n=5), medial temporal lobe (n=4), pons (n=3), both hippocampi (n=3) the insular cortex (n=2), medulla (n=2), lateral temporal lobe cortex (n=1), both cingulate gyri (n=1), both basal ganglia (n=1), and the left hemispheric cortex (n=1). These CT or MR imaging findings of acute encephalitis of unknown etiology were similar to a combination of those of Japanese encephalitis and herpes simplex encephalitis. In order to document the specific causative agents which lead to the appearance of these imaging features, further investigation is required.

  15. Working memory performance and thalamus microstructure in healthy subjects.

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    Piras, F; Caltagirone, C; Spalletta, G

    2010-12-01

    Research on the neural basis of working memory (WM) has generally focused on cortical regions, specifically frontal and parietal areas. Comparatively, evidence of a possible involvement of deep gray matter structures, that are parts of cortico-cortical circuits linking anterior and posterior cortical areas, is far less clear. The goal of the present study is to test the hypothesis that individual structural variations within deep gray matter structures may affect the cortical networks involved in WM. To this aim, a large sample (n=181) of healthy subjects underwent a high-resolution structural magnetic resonance imaging (MRI) and a diffusion tensor imaging (DTI) scan protocol. Data of micro- (mean diffusivity, MD) and macro- (volume) structural variations of six bilateral deep gray matter structures (thalamus, caudate nucleus, putamen, hippocampus, amygdala and pallidum) and lateral ventriculi volume were analyzed in association with score in a WM (the so-called n-back task) and other neuropsychological tasks. Results showed that increased MD of bilateral thalami was the only structural parameter that significantly correlated with reduced WM performance. In particular, a voxel-by-voxel analysis revealed that the greater percentage of voxels showing significant anticorrelation between WM score and MD values were localized in those thalamic nuclei projecting to prefrontal and posterior parietal cortices. Results highlight the specific involvement of thalamus microstructure, not volume, in modulating WM performance, possibly by regulating the connections among cortical areas that are recruited during WM tasks. Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Disconnection syndromes of basal ganglia, thalamus, and cerebrocerebellar systems.

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    Schmahmann, Jeremy D; Pandya, Deepak N

    2008-09-01

    Disconnection syndromes were originally conceptualized as a disruption of communication between different cerebral cortical areas. Two developments mandate a re-evaluation of this notion. First, we present a synopsis of our anatomical studies in monkey elucidating principles of organization of cerebral cortex. Efferent fibers emanate from every cortical area, and are directed with topographic precision via association fibers to ipsilateral cortical areas, commissural fibers to contralateral cerebral regions, striatal fibers to basal ganglia, and projection subcortical bundles to thalamus, brainstem and/or pontocerebellar system. We note that cortical areas can be defined by their patterns of subcortical and cortical connections. Second, we consider motor, cognitive and neuropsychiatric disorders in patients with lesions restricted to basal ganglia, thalamus, or cerebellum, and recognize that these lesions mimic deficits resulting from cortical lesions, with qualitative differences between the manifestations of lesions in functionally related areas of cortical and subcortical nodes. We consider these findings on the basis of anatomical observations from tract tracing studies in monkey, viewing them as disconnection syndromes reflecting loss of the contribution of subcortical nodes to the distributed neural circuits. We introduce a new theoretical framework for the distributed neural circuits, based on general, and specific, principles of anatomical organization, and on the architecture of the nodes that comprise these systems. We propose that neural architecture determines function, i.e., each architectonically distinct cortical and subcortical area contributes a unique transform, or computation, to information processing; anatomically precise and segregated connections between nodes define behavior; and association fiber tracts that link cerebral cortical areas with each other enable the cross-modal integration required for evolved complex behaviors. This model

  17. Glucose hypermetabolism in the thalamus of patients with hemifacial spasm.

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    Shimizu, Megumi; Suzuki, Yukihisa; Kiyosawa, Motohiro; Wakakura, Masato; Ishii, Kenji; Ishiwata, Kiichi; Mochizuki, Manabu

    2012-04-01

    The purpose of this study was investigate functional alteration in the brains of patients with hemifacial spasm using positron emission tomography (PET). We studied cerebral glucose metabolism using PET with (18) F-fluorodeoxyglucose in 13 patients with right lateral hemifacial spasm and 13 with left lateral hemifacial spasm. All patients underwent 2 PET scans before treatment (active state) and after treatment (suppressive state) with the botulinum neurotoxin type A. At the time of the PET scans, the severity of the spasm was rated according to the Jankovic Disability Rating Scale. We also used magnetic resonance imaging to evaluate the grade of neurovascular compression in each patient using scores of 1 to 3 (1 = mild, 3 = severe). Fifty-two normal volunteers were examined as controls. Compared with controls, patients with right and left hemifacial spasm showed bilateral cerebral glucose hypermetabolism in the thalamus in both the active and suppressive states. However, thalamic glucose metabolism after the suppressive state was significantly reduced compared with that in the active state using region of interest analysis. There was a positive correlation between the severity of the spasm in the active state and the score of neurovascular compression (rs = 0.65) that was estimated using Spearman order correlation coefficient. We observed bilateral cerebral glucose hypermetabolism in the thalamus of patients with hemifacial spasm. The thalamic glucose hypermetabolism may be attributed to multiple sources, including afferent input from the skin and muscle spindle, antidromic conduction of the facial nerve, and secondary alteration in the central nervous system. Copyright © 2012 Movement Disorder Society.

  18. Contributions of Volumetrics of the Hippocampus and Thalamus to Verbal Memory in Temporal Lobe Epilepsy Patients

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    Stewart, Christopher C.; Griffith, H. Randall; Okonkwo, Ozioma C.; Martin, Roy C.; Knowlton, Robert K.; Richardson, Elizabeth J.; Hermann, Bruce P.; Seidenberg, Michael

    2009-01-01

    Recent theories have posited that the hippocampus and thalamus serve distinct, yet related, roles in episodic memory. Whereas the hippocampus has been implicated in long-term memory encoding and storage, the thalamus, as a whole, has been implicated in the selection of items for subsequent encoding and the use of retrieval strategies. However,…

  19. Vasomotion and Neurovascular Coupling in the Visual Thalamus In Vivo

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    Rivadulla, Casto; de Labra, Carmen; Grieve, Kenneth L.; Cudeiro, Javier

    2011-01-01

    Spontaneous contraction and relaxation of arteries (and in some instances venules) has been termed vasomotion and has been observed in an extensive variety of tissues and species. However, its functions and underlying mechanisms are still under discussion. We demonstrate that in vivo spectrophotometry, measured simultaneously with extracellular recordings at the same locations in the visual thalamus of the cat, reveals vasomotion, measured as an oscillation (0.14hz) in the recorded oxyhemoglobin (OxyHb) signal, which appears spontaneously in the microcirculation and can last for periods of hours. During some non-oscillatory periods, maintained sensory stimulation evokes vasomotion lasting ∼30s, resembling an adaptive vascular phenomenon. This oscillation in the oxyhaemoblobin signal is sensitive to pharmacological manipulation: it is inducible by chloralose anaesthesia and it can be temporarily blocked by systemic administration of adrenaline or acetylcholine (ACh). During these oscillatory periods, neurovascular coupling (i.e. the relationship between local neural activity and the rate of blood supply to that location) appears significantly altered. This raises important questions with regard to the interpretation of results from studies currently dependent upon a linear relationship between neural activity and blood flow, such as neuroimaging. PMID:22174886

  20. Multiplexed Spike Coding and Adaptation in the Thalamus

    Directory of Open Access Journals (Sweden)

    Rebecca A. Mease

    2017-05-01

    Full Text Available High-frequency “burst” clusters of spikes are a generic output pattern of many neurons. While bursting is a ubiquitous computational feature of different nervous systems across animal species, the encoding of synaptic inputs by bursts is not well understood. We find that bursting neurons in the rodent thalamus employ “multiplexing” to differentially encode low- and high-frequency stimulus features associated with either T-type calcium “low-threshold” or fast sodium spiking events, respectively, and these events adapt differently. Thus, thalamic bursts encode disparate information in three channels: (1 burst size, (2 burst onset time, and (3 precise spike timing within bursts. Strikingly, this latter “intraburst” encoding channel shows millisecond-level feature selectivity and adapts across statistical contexts to maintain stable information encoded per spike. Consequently, calcium events both encode low-frequency stimuli and, in parallel, gate a transient window for high-frequency, adaptive stimulus encoding by sodium spike timing, allowing bursts to efficiently convey fine-scale temporal information.

  1. Vasomotion and neurovascular coupling in the visual thalamus in vivo.

    Directory of Open Access Journals (Sweden)

    Casto Rivadulla

    Full Text Available Spontaneous contraction and relaxation of arteries (and in some instances venules has been termed vasomotion and has been observed in an extensive variety of tissues and species. However, its functions and underlying mechanisms are still under discussion. We demonstrate that in vivo spectrophotometry, measured simultaneously with extracellular recordings at the same locations in the visual thalamus of the cat, reveals vasomotion, measured as an oscillation (0.14 hz in the recorded oxyhemoglobin (OxyHb signal, which appears spontaneously in the microcirculation and can last for periods of hours. During some non-oscillatory periods, maintained sensory stimulation evokes vasomotion lasting ~30s, resembling an adaptive vascular phenomenon. This oscillation in the oxyhaemoblobin signal is sensitive to pharmacological manipulation: it is inducible by chloralose anaesthesia and it can be temporarily blocked by systemic administration of adrenaline or acetylcholine (ACh. During these oscillatory periods, neurovascular coupling (i.e. the relationship between local neural activity and the rate of blood supply to that location appears significantly altered. This raises important questions with regard to the interpretation of results from studies currently dependent upon a linear relationship between neural activity and blood flow, such as neuroimaging.

  2. Gating of attentional effort through the central thalamus.

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    Schiff, N D; Shah, S A; Hudson, A E; Nauvel, T; Kalik, S F; Purpura, K P

    2013-02-01

    The central thalamus plays an important role in the regulation of arousal and allocation of attentional resources in the performance of even simple tasks. To assess the contribution of central thalamic neurons to short-term adjustments of attentional effort, we analyzed 166 microelectrode recordings obtained from two rhesus monkeys performing a visuomotor simple reaction time task with a variable foreperiod. Multiunit responses showed maintained firing rate elevations during the variable delay period of the task in ∼24% of recording sites. Simultaneously recorded local field potentials demonstrated significant decreases in power at ∼10-20 Hz and increases in power at 30-100 Hz during the delay period when compared against precue baselines. Comparison of the spectral power of local field potentials during the delay period of correct and incorrect trials showed that, during incorrect trials, similar, but reduced, shifts of spectral power occurred within the same frequency bands. Sustained performance of even simple tasks requires regulation of arousal and attention that combine in the concept of "attentional effort". Our findings suggest that central thalamic neurons regulate task performance through brief changes in firing rates and spectral power changes during task-relevant short-term shifts of attentional effort. Increases in attentional effort may be reflected in changes within the central thalamic local populations, where correct task performance associates with more robust maintenance of firing rates during the delay period. Such ongoing fluctuations of central thalamic activity likely reflect a mix of influences, including variations in moment-to-moment levels of motivation, arousal, and availability of cognitive resources.

  3. Correlation transfer from basal ganglia to thalamus in Parkinson's disease

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    Pamela, Reitsma; Brent, Doiron; Jonathan, Rubin

    2011-01-01

    Spike trains from neurons in the basal ganglia of parkinsonian primates show increased pairwise correlations, oscillatory activity, and burst rate compared to those from neurons recorded during normal brain activity. However, it is not known how these changes affect the behavior of downstream thalamic neurons. To understand how patterns of basal ganglia population activity may affect thalamic spike statistics, we study pairs of model thalamocortical (TC) relay neurons receiving correlated inhibitory input from the internal segment of the globus pallidus (GPi), a primary output nucleus of the basal ganglia. We observe that the strength of correlations of TC neuron spike trains increases with the GPi correlation level, and bursty firing patterns such as those seen in the parkinsonian GPi allow for stronger transfer of correlations than do firing patterns found under normal conditions. We also show that the T-current in the TC neurons does not significantly affect correlation transfer, despite its pronounced effects on spiking. Oscillatory firing patterns in GPi are shown to affect the timescale at which correlations are best transferred through the system. To explain this last result, we analytically compute the spike count correlation coefficient for oscillatory cases in a reduced point process model. Our analysis indicates that the dependence of the timescale of correlation transfer is robust to different levels of input spike and rate correlations and arises due to differences in instantaneous spike correlations, even when the long timescale rhythmic modulations of neurons are identical. Overall, these results show that parkinsonian firing patterns in GPi do affect the transfer of correlations to the thalamus. PMID:22355287

  4. Dopamine controls Parkinson's tremor by inhibiting the cerebellar thalamus.

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    Dirkx, Michiel F; den Ouden, Hanneke E M; Aarts, Esther; Timmer, Monique H M; Bloem, Bastiaan R; Toni, Ivan; Helmich, Rick C

    2017-03-01

    Parkinson's resting tremor is related to altered cerebral activity in the basal ganglia and the cerebello-thalamo-cortical circuit. Although Parkinson's disease is characterized by dopamine depletion in the basal ganglia, the dopaminergic basis of resting tremor remains unclear: dopaminergic medication reduces tremor in some patients, but many patients have a dopamine-resistant tremor. Using pharmacological functional magnetic resonance imaging, we test how a dopaminergic intervention influences the cerebral circuit involved in Parkinson's tremor. From a sample of 40 patients with Parkinson's disease, we selected 15 patients with a clearly tremor-dominant phenotype. We compared tremor-related activity and effective connectivity (using combined electromyography-functional magnetic resonance imaging) on two occasions: ON and OFF dopaminergic medication. Building on a recently developed cerebral model of Parkinson's tremor, we tested the effect of dopamine on cerebral activity associated with the onset of tremor episodes (in the basal ganglia) and with tremor amplitude (in the cerebello-thalamo-cortical circuit). Dopaminergic medication reduced clinical resting tremor scores (mean 28%, range -12 to 68%). Furthermore, dopaminergic medication reduced tremor onset-related activity in the globus pallidus and tremor amplitude-related activity in the thalamic ventral intermediate nucleus. Network analyses using dynamic causal modelling showed that dopamine directly increased self-inhibition of the ventral intermediate nucleus, rather than indirectly influencing the cerebello-thalamo-cortical circuit through the basal ganglia. Crucially, the magnitude of thalamic self-inhibition predicted the clinical dopamine response of tremor. Dopamine reduces resting tremor by potentiating inhibitory mechanisms in a cerebellar nucleus of the thalamus (ventral intermediate nucleus). This suggests that altered dopaminergic projections to the cerebello-thalamo-cortical circuit have a role

  5. The tale of the three brothers - Shh, Wnt and Fgf during development of the thalamus

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    Anja IH Hagemann

    2012-05-01

    Full Text Available The thalamic complex is an essential part of the brain that requires a combination of specialized activities to attain its final complexity. In the following review we will describe the induction process of the mid-diencephalic organizer (MDO where three different signaling pathways merge: Wnt, Shh and Fgf. Here, we dissect the function of each signaling pathway in the thalamus in chronological order of their appearance. First we describe the Wnt mediated induction of the MDO and compartition of the caudal forebrain, then the Shh mediated determination of proneural gene expression before discussing recent progress in characterizing Fgf function during thalamus development. Then, we focus on transcription factors, which are regulated by these pathways and which play a pivotal role in neurogenesis in the thalamus. The three signaling pathways act together in a strictly regulated chronology to orchestrate the development of the entire thalamus.

  6. Nitric oxide synthase-containing projections to the ventrobasal thalamus in the rat.

    Science.gov (United States)

    Usunoff, K G; Kharazia, V N; Valtschanoff, J G; Schmidt, H H; Weinberg, R J

    1999-09-01

    Microiontophoretic studies of thalamic neurons suggests that nitric oxide (NO) plays an important role in mediating somatosensory transmission. The thalamus contains few nitric oxide synthase (NOS)-immunoreactive neurons; thus, the major source of thalamic NO is presumably from NOS-positive axons of extrathalamic origin. The cells of origin of these putative NOS-containing pathways to the ventrobasal thalamus were investigated in rats by combining retrograde tracing with immunocytochemistry for NOS. The location and morphology of double-labeled neurons was compared with that of single-labeled neurons. The most significant sources of NOS-containing afferents to the thalamus were found to be the pedunculopontine (PPN) and laterodorsal tegmental (LDT) nuclei. NOS-immunoreactive neurons in these cholinergic nuclei project bilaterally to the thalamus, most strongly ipsilaterally. The thalamus appears to be a major target of PPN, since even selective thalamic injections result in retrograde labeling of at least one third of its NOS-immunoreactive neurons. A significant number of NOS-negative neurons in both the PPN and LDT also project to the thalamus. Minor sources of NOS-containing thalamic afferents include the lateral hypothalamus, the dorsal, median and pontine raphe nuclei, the parabrachial nuclei, and the pontomedullary reticular formation. In all these structures, NOS-negative thalamopetal neurons greatly outnumber the NOS-positive ones. Ascending sensory pathways to the thalamus, including those from the sensory trigeminal nuclei, the dorsal column nuclei, and the spinal cord, as well as the auditory and vestibular centers, arise exclusively from NOS-negative neurons. The major NOS-positive projections are implicated in affective and alerting systems, supporting that NO may act to modulate attentiveness in thalamic relay nuclei.

  7. Interaction between Thalamus and Hippocampus in Termination of Amygdala-Kindled Seizures in Mice

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    Zhen Zhang

    2016-01-01

    Full Text Available The thalamus and hippocampus have been found both involved in the initiation, propagation, and termination of temporal lobe epilepsy. However, the interaction of these regions during seizures is not clear. The present study is to explore whether some regular patterns exist in their interaction during the termination of seizures. Multichannel in vivo recording techniques were used to record the neural activities from the cornu ammonis 1 (CA1 of hippocampus and mediodorsal thalamus (MDT in mice. The mice were kindled by electrically stimulating basolateral amygdala neurons, and Racine’s rank standard was employed to classify the stage of behavioral responses (stage 1~5. The coupling index and directionality index were used to investigate the synchronization and information flow direction between CA1 and MDT. Two main results were found in this study. (1 High levels of synchronization between the thalamus and hippocampus were observed before the termination of seizures at stage 4~5 but after the termination of seizures at stage 1~2. (2 In the end of seizures at stage 4~5, the information tended to flow from MDT to CA1. Those results indicate that the synchronization and information flow direction between the thalamus and the hippocampus may participate in the termination of seizures.

  8. Brief Report: Abnormal Association between the Thalamus and Brain Size in Asperger's Disorder

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    Hardan, Antonio Y.; Girgis, Ragy R.; Adams, Jason; Gilbert, Andrew R.; Melhem, Nadine M.; Keshavan, Matcheri S.; Minshew, Nancy J.

    2008-01-01

    The objective of this study was to examine the relationship between thalamic volume and brain size in individuals with Asperger's disorder (ASP). Volumetric measurements of the thalamus were performed on MRI scans obtained from 12 individuals with ASP (age range: 10-35 years) and 12 healthy controls (age range: 9-33 years). A positive correlation…

  9. Disease-specific structural changes in thalamus and dentatorubrothalamic tract in progressive supranuclear palsy

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    Surova, Yulia; Hall, Sara; Widner, Haakan [Lund University, Department of Clinical Sciences, Lund (Sweden); Skaane University Hospital, Department of Neurology, Lund (Sweden); Nilsson, Markus [Lund University, Lund University Bioimaging Center, Lund (Sweden); Laett, Jimmy [Skaane University Hospital, Center for Medical Imaging and Physiology, Lund (Sweden); Lampinen, Bjoern [Lund University, Department of Medical Radiation Physics, Lund (Sweden); Lindberg, Olof [Malmoe, Lund University, Department of Clinical Sciences, Malmoe (Sweden); Nilsson, Christer [Skaane University Hospital, Department of Neurology, Lund (Sweden); Malmoe, Lund University, Department of Clinical Sciences, Malmoe (Sweden); Westen, Danielle van [Lund University, Department of Clinical Sciences, Lund (Sweden); Skaane University Hospital, Center for Medical Imaging and Physiology, Lund (Sweden); Hansson, Oskar [Malmoe, Lund University, Department of Clinical Sciences, Malmoe (Sweden); Skaane University Hospital, Memory Clinic, Lund (Sweden)

    2015-11-15

    The aim of this study is to identify disease-specific changes of the thalamus, basal ganglia, pons, and midbrain in patients with progressive supranuclear palsy (PSP), Parkinson's disease (PD), and multiple system atrophy with predominant parkinsonism (MSA-P) using diffusion tensor imaging and volumetric analysis. MRI diffusion and volumetric data were acquired in a derivation of 30 controls and 8 patients with PSP and a validation cohort comprised of controls (n = 21) and patients with PSP (n = 27), PD (n = 10), and MSA-P (n = 11). Analysis was performed using regions of interest (ROI), tract-based spatial statistic (TBSS), and tractography and results compared between diagnostic groups. In the derivation cohort, we observed increased mean diffusivity (MD) in the thalamus, superior cerebellar peduncle, and the midbrain in PSP compared to controls. Furthermore, volumetric analysis showed reduced thalamic volumes in PSP. In the validation cohort, the observations of increased MD were replicated by ROI-based analysis and in the thalamus by TBSS-based analysis. Such differences were not found for patients with PD in any of the cohorts. Tractography of the dentatorubrothalamic tract (DRTT) showed increased MD in PSP patients from both cohorts compared to controls and in the validation cohort in PSP compared to PD and MSA patients. Increased MD in the thalamus and along the DRTT correlated with disease stage and motor function in PSP. Patients with PSP, but not PD or MSA-P, exhibit signs of structural abnormalities in the thalamus and in the DRTT. These changes are associated with disease stage and impaired motor function. (orig.)

  10. Altered network properties of the fronto-parietal network and the thalamus in impaired consciousness

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    Julia Sophia Crone

    2014-01-01

    In chronic disorders of consciousness, modularity at the global level was reduced suggesting a disturbance in the optimal balance between segregation and integration. Moreover, network properties were altered in several regions which are associated with conscious processing (particularly, in medial parietal, and frontal regions, as well as in the thalamus. Between minimally conscious and unconscious patients the local efficiency of medial parietal regions differed. Alterations in the thalamus were particularly evident in non-conscious patients. Most of the regions affected in patients with impaired consciousness belong to the so-called ‘rich club’ of highly interconnected central nodes. Disturbances in their topological characteristics have severe impact on information integration and are reflected in deficits in cognitive functioning probably leading to a total breakdown of consciousness.

  11. Diffusion tensor imaging reveals thalamus and posterior cingulate cortex abnormalities in internet gaming addicts.

    Science.gov (United States)

    Dong, Guangheng; DeVito, Elise; Huang, Jie; Du, Xiaoxia

    2012-09-01

    Internet gaming addiction (IGA) is increasingly recognized as a widespread disorder with serious psychological and health consequences. Diminished white matter integrity has been demonstrated in a wide range of other addictive disorders which share clinical characteristics with IGA. Abnormal white matter integrity in addictive populations has been associated with addiction severity, treatment response and cognitive impairments. This study assessed white matter integrity in individuals with internet gaming addiction (IGA) using diffusion tensor imaging (DTI). IGA subjects (N = 16) showed higher fractional anisotropy (FA), indicating greater white matter integrity, in the thalamus and left posterior cingulate cortex (PCC) relative to healthy controls (N = 15). Higher FA in the thalamus was associated with greater severity of internet addiction. Increased regional FA in individuals with internet gaming addiction may be a pre-existing vulnerability factor for IGA, or may arise secondary to IGA, perhaps as a direct result of excessive internet game playing. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. How Vestibular Neurons Solve the Tilt/Translation Ambiguity: Comparison of Brainstem, Cerebellum, and Thalamus

    OpenAIRE

    Dora E. Angelaki; Yakusheva, Tatyana A.

    2009-01-01

    The peripheral vestibular system is faced by a sensory ambiguity, where primary otolith afferents respond identically to translational (inertial) accelerations and changes in head orientation relative to gravity. Under certain conditions, this sensory ambiguity can be resolved using extra-otolith cues, including semicircular canal signals. Here we review and summarize how neurons in the vestibular nuclei, rostral fastigial nuclei, cerebellar nodulus/uvula, and thalamus respond during combinat...

  13. Brain blood-flow changes during motion sickness. [thalamus vascular changes in dogs during swing tests

    Science.gov (United States)

    Johnson, W. H.; Hsuen, J.

    1973-01-01

    The possibility of diminished blood flow in the brain is studied as one of the factors resulting from an increase in skeletal muscle blood volume concomitant with other characteristics of motion sickness. Thermistors are implanted in the thalamus of dogs and blood flow changes are recorded while they are subjected to sinusoidal movement on a two pole swing. Results of these initial steps in a proposed long term exploration of different areas of the brain are presented.

  14. Neo-Timm staining in the thalamus of chronically epileptic rats

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    Hamani C.

    2005-01-01

    Full Text Available The thalamus is an important modulator of seizures and is severely affected in cholinergic models of epilepsy. In the present study, chronically epileptic rats had their brains processed for neo-Timm and acetylcholinesterase two months after the induction of status epilepticus with pilocarpine. Both controls and pilocarpine-treated animals presented neo-Timm staining in the anterodorsal nucleus, laterodorsal nucleus, reticular nucleus, most intralaminar nuclei, nucleus reuniens, and rhomboid nucleus of the thalamus, as well as in the zona incerta. The intensity of neo-Timm staining was similar in control and pilocarpine-treated rats, except for the nucleus reuniens and the rhomboid nucleus, which had a lower intensity of staining in the epileptic group. In animal models of temporal lobe epilepsy, zinc seems to modulate glutamate release and to decrease seizure activity. In this context, a reduction of neo-Timm-stained terminals in the midline thalamus could ultimately result in an increased excitatory activity, not only within its related nuclei, but also in anatomical structures that receive their efferent connections. This might contribute to the pathological substrate observed in chronic pilocarpine-treated epileptic animals.

  15. Effects of neonatal excitotoxic lesions in ventral thalamus on social interaction in the rat.

    Science.gov (United States)

    Wolf, Rainer; Dobrowolny, Henrik; Nullmeier, Sven; Bogerts, Bernhard; Schwegler, Herbert

    2017-03-30

    The role of the thalamus in schizophrenia has increasingly been studied in recent years. Deficits in the ventral thalamus have been described in only few postmortem and neuroimaging studies. We utilised our previously introduced neurodevelopmental animal model, the neonatal excitotoxic lesion of the ventral thalamus of Sprague-Dawley rats (Wolf et al., Pharmacopsychiatry 43:99-109, 22). At postnatal day (PD7), male pubs received bilateral thalamic infusions with ibotenic acid (IBA) or artificial cerebrospinal fluid (control). In adulthood, social interaction of two animals not familiar to each other was studied by a computerised video tracking system. This study displays clear lesion effects on social interaction of adult male rats. The significant reduction of total contact time and the significant increase in distance between the animals in the IBA group compared to controls can be interpreted as social withdrawal modelling a negative symptom of schizophrenia. The significant increase of total distance travelled in the IBA group can be hypothesised as agitation modelling a positive symptom of schizophrenia. Using a triple concept of social interaction, the percentage of no social interaction (Non-SI%) was significantly larger, and inversely, the percentage of passive social interaction (SI-passive%) was significantly smaller in the IBA group when compared to controls. In conclusion, on the background of findings in schizophrenic patients, the effects of neonatal ventral thalamic IBA lesions in adult male rats support the hypothesis of face and construct validity as animal model of schizophrenia.

  16. Early Exposure to General Anesthesia with Isoflurane Downregulates Inhibitory Synaptic Neurotransmission in the Rat Thalamus.

    Science.gov (United States)

    Joksovic, Pavle M; Lunardi, Nadia; Jevtovic-Todorovic, Vesna; Todorovic, Slobodan M

    2015-10-01

    Recent evidence supports the idea that common general anesthetics (GAs) such as isoflurane (Iso) and nitrous oxide (N2O; laughing gas) are neurotoxic and may harm the developing mammalian brain, including the thalamus; however, to date very little is known about how developmental exposure to GAs may affect synaptic transmission in the thalamus which, in turn, controls the function of thalamocortical circuitry. To address this issue we used in vitro patch-clamp recordings of evoked inhibitory postsynaptic currents (eIPSCs) from intact neurons of the nucleus reticularis thalami (nRT) in brain slices from rat pups (postnatal age P10-P18) exposed at age of P7 to clinically relevant GA combinations of Iso and N2O. We found that rats exposed to a combination of 0.75 % Iso and 75 % N2O display lasting reduction in the amplitude and faster decays of eIPSCs. Exposure to sub-anesthetic concentrations of 75 % N2O alone or 0.75 % Iso alone at P7 did not affect the amplitude of eIPSCs; however, Iso alone, but not N2O, significantly accelerated decay of eIPSCs. Anesthesia with 1.5 % Iso alone decreased amplitudes, caused faster decay and decreased the paired-pulse ratio of eIPSCs. We conclude that anesthesia at P7 with Iso alone or in combination with N2O causes plasticity of eIPSCs in nRT neurons by both presynaptic and postsynaptic mechanisms. We hypothesize that changes in inhibitory synaptic transmission in the thalamus induced by GAs may contribute to altered neuronal excitability and consequently abnormal thalamocortical oscillations later in life.

  17. Sensory percepts induced by microwire array and DBS microstimulation in human sensory thalamus.

    Science.gov (United States)

    Swan, Brandon D; Gasperson, Lynne B; Krucoff, Max O; Grill, Warren M; Turner, Dennis A

    2017-10-27

    Microstimulation in human sensory thalamus (ventrocaudal, VC) results in focal sensory percepts in the hand and arm which may provide an alternative target site (to somatosensory cortex) for the input of prosthetic sensory information. Sensory feedback to facilitate motor function may require simultaneous or timed responses across separate digits to recreate perceptions of slip as well as encoding of intensity variations in pressure or touch. To determine the feasibility of evoking sensory percepts on separate digits with variable intensity through either a microwire array or deep brain stimulation (DBS) electrode, recreating "natural" and scalable percepts relating to the arm and hand. We compared microstimulation within ventrocaudal sensory thalamus through either a 16-channel microwire array (∼400 kΩ per channel) or a 4-channel DBS electrode (∼1.2 kΩ per contact) for percept location, size, intensity, and quality sensation, during thalamic DBS electrode placement in patients with essential tremor. Percepts in small hand or finger regions were evoked by microstimulation through individual microwires and in 5/6 patients sensation on different digits could be perceived from stimulation through separate microwires. Microstimulation through DBS electrode contacts evoked sensations over larger areas in 5/5 patients, and the apparent intensity of the perceived response could be modulated with stimulation amplitude. The perceived naturalness of the sensation depended both on the pattern of stimulation as well as intensity of the stimulation. Producing consistent evoked perceptions across separate digits within sensory thalamus is a feasible concept and a compact alternative to somatosensory cortex microstimulation for prosthetic sensory feedback. This approach will require a multi-element low impedance electrode with a sufficient stimulation range to evoke variable intensities of perception and a predictable spread of contacts to engage separate digits

  18. Error-related functional connectivity of the thalamus in cocaine dependence

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    Sheng Zhang

    2014-01-01

    Full Text Available Error processing is a critical component of cognitive control, an executive function that has been widely implicated in substance misuse. In previous studies we showed that error related activations of the thalamus predicted relapse to drug use in cocaine addicted individuals (Luo et al., 2013. Here, we investigated whether the error-related functional connectivity of the thalamus is altered in cocaine dependent patients (PCD, n = 54 as compared to demographically matched healthy individuals (HC, n = 54. The results of a generalized psychophysiological interaction analysis showed negative thalamic connectivity with the ventral medial prefrontal cortex (vmPFC, in the area of perigenual and subgenual anterior cingulate cortex, in HC but not PCD (p < 0.05, corrected, two-sample t test. This difference in functional connectivity was not observed for task-residual signals, suggesting that it is specific to task-related processes during cognitive control. Further, the thalamic-vmPFC connectivity is positively correlated with the amount of cocaine use in the prior month for female but not for male PCD. These findings add to recent literature and provide additional evidence for circuit-level biomarkers of cocaine dependence.

  19. Activation of thalamus in motor imagery results from gating by hypnosis.

    Science.gov (United States)

    Müller, Katharina; Bacht, Katrin; Prochnow, Denise; Schramm, Stefanie; Seitz, Rüdiger J

    2013-02-01

    The ability to mentally imagine the performance of automatic movements has been well-established being employed in sports and physiotherapy as a tool for motor learning and rehabilitation. This is probably mediated by engagement of the same brain areas as during real motor performance. Here we investigated the effect of hypnotic trance on the cerebral activation pattern engaged in motor imagery in 16 healthy, right-handed subjects using fMRI. Motor imagery as compared with rest was related to activations in the left medial frontal areas (preSMA/SMA), prefrontal- and frontal areas, putamen and inferior parietal areas. When compared with performance of the same movements motor imagery resulted in activation of the left middle frontal cortex, precuneus, and posterior cingulate. Under hypnotic trance there was one extra-activation in the left thalamus which occurred specifically in the motor imagery condition. The regional beta indices were highly correlated among the areas of the cortical-subcortical motor network. Our data accord with the notion that hypnotic trance enhances the motor control circuit engaged in motor imagery by modulating the gating function of the thalamus. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. [Thalamic dementia due to infarct of the left thalamus and genum of the right internal capsule].

    Science.gov (United States)

    Porta-Etessam, J; Martínez-Salio, A; Berbel, A; Benito-León, J; García-Muñoz, A; Kesler, P; Mateo, S

    Thalamic dementia is the clinical consequence of a disorder of both thalami. It is generally secondary to bilateral paramedial thalamic infarcts due to disorders of small blood vessels or cardioembolism. We report a case of dementia of acute onset involving the left thalamus and the genum of the right internal capsule. A 33 year old man, HIV positive, category B2, admitted to hospital for tuberculous meningitis presented with the acute onset of somnolence, followed by marked bradypsychism, personality changes, marked disorder of executive explicit memory without associated praxic, gnosic or language disorders. Ocular motility remained normal. There was left central facial paralysis with inverse emotive voluntary dissociation. The other cranial nerves were normal. There was left hemiparesia with extensor plantar reflex. No other alterations. Cerebral MR imaging was compatible with paramedial infarcts of the left thalamus and genum of the right internal capsule. Thalamic dementia generally occurs in bilateral paramedian thalamic disorders. There are cases of disorders of executive memory secondary to infarcts of the genum of the internal capsule due to interruption of the thalamotemporal pathways and a contralateral paramedial thalamic lesion.

  1. The neurobiology of thalamic amnesia: Contributions of medial thalamus and prefrontal cortex to delayed conditional discrimination.

    Science.gov (United States)

    Mair, Robert G; Miller, Rikki L A; Wormwood, Benjamin A; Francoeur, Miranda J; Onos, Kristen D; Gibson, Brett M

    2015-07-01

    Although medial thalamus is well established as a site of pathology associated with global amnesia, there is uncertainty about which structures are critical and how they affect memory function. Evidence from human and animal research suggests that damage to the mammillothalamic tract and the anterior, mediodorsal (MD), midline (M), and intralaminar (IL) nuclei contribute to different signs of thalamic amnesia. Here we focus on MD and the adjacent M and IL nuclei, structures identified in animal studies as critical nodes in prefrontal cortex (PFC)-related pathways that are necessary for delayed conditional discrimination. Recordings of PFC neurons in rats performing a dynamic delayed non-matching-to position (DNMTP) task revealed discrete populations encoding information related to planning, execution, and outcome of DNMTP-related actions and delay-related activity signaling previous reinforcement. Parallel studies recording the activity of MD and IL neurons and examining the effects of unilateral thalamic inactivation on the responses of PFC neurons demonstrated a close coupling of central thalamic and PFC neurons responding to diverse aspects of DNMTP and provide evidence that thalamus interacts with PFC neurons to give rise to complex goal-directed behavior exemplified by the DNMTP task. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. The role of the anterior, mediodorsal, and parafascicular thalamus in instrumental conditioning.

    Science.gov (United States)

    Bradfield, Laura A; Hart, Genevra; Balleine, Bernard W

    2013-10-09

    The traditional animal model of instrumental behavior has focused almost exclusively on structures within the cortico-striatal network and ignored the contributions of various thalamic nuclei despite large and specific connections with each of these structures. One possible reason for this is that the thalamus has been conventionally viewed as a mediator of general processes, such as attention, arousal and movement, that are not easily separated from more cognitive aspects of instrumental behavior. Recent research has, however, begun to separate these roles. Here we review the role of three thalamic nuclei in instrumental conditioning: the anterior thalamic nuclei (ANT), the mediodorsal (MD), and parafascicular thalamic nuclei (PF). Early research suggested that ANT might regulate aspects of instrumental behavior but, on review, we suggest that the types of tasks used in these studies were more likely to recruit Pavlovian processes. Indeed lesions of ANT have been found to have no effect on performance in instrumental free-operant tasks. By contrast the mediodorsal thalamus (MD) has been found to play a specific and important role in the acquisition of goal-directed action. We propose this role is related to its connections with prelimbic cortex (PL) and present new data that directly implicates this circuit in the acquisition of goal-directed actions. Finally we review evidence suggesting the PF, although not critical for the acquisition or performance of instrumental actions, plays a specific role in regulating action flexibility.

  3. Postmortem diffusion MRI of the human brainstem and thalamus for deep brain stimulator electrode localization.

    Science.gov (United States)

    Calabrese, Evan; Hickey, Patrick; Hulette, Christine; Zhang, Jingxian; Parente, Beth; Lad, Shivanand P; Johnson, G Allan

    2015-08-01

    Deep brain stimulation (DBS) is an established surgical therapy for medically refractory tremor disorders including essential tremor (ET) and is currently under investigation for use in a variety of other neurologic and psychiatric disorders. There is growing evidence that the anti-tremor effects of DBS for ET are directly related to modulation of the dentatorubrothalamic tract (DRT), a white matter pathway that connects the cerebellum, red nucleus, and ventral intermediate nucleus of the thalamus. Emerging white matter targets for DBS, like the DRT, will require improved three-dimensional (3D) reference maps of deep brain anatomy and structural connectivity for accurate electrode targeting. High-resolution diffusion MRI of postmortem brain specimens can provide detailed volumetric images of important deep brain nuclei and 3D reconstructions of white matter pathways with probabilistic tractography techniques. We present a high spatial and angular resolution diffusion MRI template of the postmortem human brainstem and thalamus with 3D reconstructions of the nuclei and white matter tracts involved in ET circuitry. We demonstrate registration of these data to in vivo, clinical images from patients receiving DBS therapy, and correlate electrode proximity to tractography of the DRT with improvement of ET symptoms. © 2015 Wiley Periodicals, Inc.

  4. The role of the anterior, mediodorsal, and parafascicular thalamus in instrumental conditioning

    Directory of Open Access Journals (Sweden)

    Laura Anne Bradfield

    2013-10-01

    Full Text Available The traditional animal model of instrumental behaviour has focused almost exclusively on structures within the cortico-striatal network and ignored the contributions of various thalamic nuclei despite large and specific connections with each of these structures. One possible reason for this is that the thalamus has been conventionally viewed as a mediator of general processes, such as attention, arousal and movement, that are not easily separated from more cognitive aspects of instrumental behaviour. Recent research has, however, begun to separate these roles. Here we review the role of three thalamic nuclei in instrumental conditioning: the anterior, the mediodorsal, and parafascicular thalamic nuclei. Early research suggested that anterior thalamic nuclei might regulate aspects of instrumental behaviour but, on review, we suggest that the types of tasks used in these studies were more likely to recruit Pavlovian processes. Indeed lesions of anterior thalamic nuclei have been found to have no effect on performance in instrumental free-operant tasks. By contrast the mediodorsal thalamus has been found to play a specific and important role in the acquisition of goal-directed action. We propose this role is related to its connections with prelimbic cortex and present new data that directly implicates this circuit in the acquisition of goal-directed actions. Finally we review evidence suggesting the parafascicular thalamic nucleus, although not critical for the acquisition or performance of instrumental actions, plays a specific role in regulating action flexibility.

  5. How vestibular neurons solve the tilt/translation ambiguity. Comparison of brainstem, cerebellum, and thalamus.

    Science.gov (United States)

    Angelaki, Dora E; Yakusheva, Tatyana A

    2009-05-01

    The peripheral vestibular system is faced by a sensory ambiguity, where primary otolith afferents respond identically to translational (inertial) accelerations and changes in head orientation relative to gravity. Under certain conditions, this sensory ambiguity can be resolved using extra-otolith cues, including semicircular canal signals. Here we review and summarize how neurons in the vestibular nuclei, rostral fastigial nuclei, cerebellar nodulus/uvula, and thalamus respond during combinations of tilt and translation. We focus primarily on cerebellar cortex responses, as nodulus/uvula Purkinje cells reliably encode translation rather than net gravito-inertial acceleration. In contrast, neurons in the vestibular and rostral fastigial nuclei, as well as the ventral lateral and ventral posterior nuclei of the thalamus represent a continuum, with some encoding translation and some net gravito-inertial acceleration. This review also outlines how Purkinje cells use semicircular canal signals to solve the ambiguity problem and how this solution fails at low frequencies. We conclude by attempting to bridge the gap between the proposed roles of nodulus/uvula in tilt/translation discrimination and velocity storage.

  6. Discrete Pattern of Burst Stimulation in the Ventrobasal Thalamus for Anti-Nociception

    Science.gov (United States)

    Huh, Yeowool; Cho, Jeiwon

    2013-01-01

    The thalamus has been proposed to play a role in sensory modulation via switching between tonic and burst dual firing of individual neurons. Of the two firing modes, altered burst firing has been repeatedly implicated with pathological pain conditions, which suggests that maintaining a certain form of thalamic burst could be crucial for controlling pain. However, specific elements of burst firing that may contribute to pain control have not yet been actively investigated. Utilizing the deep brain stimulation (DBS) technique, we explored the effects of bursting properties in pain control by electrically stimulating the ventrobasal (VB) thalamus in forms of burst patterned to test different aspects of bursts during the formalin induced nociception in mice. Our results demonstrated that electrical stimulations mimicking specific burst firing properties are important in producing an anti-nociceptive effect and found that the ≤3 ms interval between burst pluses (intra-burst-interval: IntraBI) and ≥3 pulses per burst were required to reliably reduce formalin induced nociceptive responses in mice. Periodicity of IntraBI was also suggested to contribute to anti-nociception to a limited extent. PMID:23950787

  7. Behavioral and cognitive changes after early postnatal lesions of the rat mediodorsal thalamus

    Science.gov (United States)

    Ouhaz, Zakaria; Ba-M’hamed, Saadia; Mitchell, Anna S.; Elidrissi, Abdeslem; Bennis, Mohamed

    2015-01-01

    Early insults to the thalamus result in functional and/or structural abnormalities in the cerebral cortex. However, differences in behavioral and cognitive changes after early insult are not well characterized. The present study assessed whether early postnatal damage to mediodorsal nucleus of the thalamus (MD), reciprocally interconnected with the prefrontal cortex, causes behavioral and cognitive alterations in young adult rats. Rat pups at postnatal day 4 received bilateral electrolytic lesion of MD, or a MD Sham lesion or were anesthetized controls; on recovery they were returned to their mothers until weaning. Seven weeks later, all rats were tested with the following behavioral and cognitive paradigms: T-maze test, open field test, actimetry, elevated plus maze test, social interactions test and passive avoidance test. Rats with bilateral MD damage presented with disrupted recognition memory, deficits in shifting response rules, significant hypoactivity, increased anxiety-like behavior, deficits in learning associations as well as decreased locomotor activity, and reduced social interactions compared to MD Sham lesion and anesthetized Control rats. The lesion also caused significant decreases in pyramidal cell density in three frontal cortex regions: medial infralimbic cortex, dorsolateral anterior cortex, and cingulate Cg1 cortex. The present findings suggest a functional role for MD in the postnatal maturation of affective behavior. Further some of the behavioral and cognitive alterations observed in these young adult rats after early MD lesion are reminiscent of those present in major psycho-affective disorders, such as schizophrenia in humans. PMID:26079768

  8. Neuronal correlates of ketamine and walking induced gamma oscillations in the medial prefrontal cortex and mediodorsal thalamus.

    Directory of Open Access Journals (Sweden)

    Katrina E Furth

    Full Text Available Alterations in the function of the medial prefrontal cortex (mPFC and its major thalamic source of innervation, the mediodorsal (MD thalamus, have been hypothesized to contribute to the symptoms of schizophrenia. The NMDAR antagonist ketamine, used to model schizophrenia, elicits a brain state resembling early stage schizophrenia characterized by cognitive deficits and increases in cortical low gamma (40-70 Hz power. Here we sought to determine how ketamine differentially affects spiking and gamma local field potential (LFP activity in the rat mPFC and MD thalamus. Additionally, we investigated the ability of drugs targeting the dopamine D4 receptor (D4R to modify the effects of ketamine on gamma activity as a measure of potential cognitive therapeutic efficacy. Rats were trained to walk on a treadmill to reduce confounds related to hyperactivity after ketamine administration (10 mg/kg s.c. while recordings were obtained from electrodes chronically implanted in the mPFC and MD thalamus. Ketamine increased gamma LFP power in mPFC and MD thalamus in a similar frequency range, yet did not increase thalamocortical synchronization. Ketamine also increased firing rates and spike synchronization to gamma oscillations in the mPFC but decreased both measures in MD thalamus. Conversely, walking alone increased both firing rates and spike-gamma LFP correlations in both mPFC and MD thalamus. The D4R antagonist alone (L-745,870 had no effect on gamma LFP power during treadmill walking, although it reversed increases induced by the D4R agonist (A-412997 in both mPFC and MD thalamus. Neither drug altered ketamine-induced changes in gamma power or firing rates in the mPFC. However, in MD thalamus, the D4R agonist increased ketamine-induced gamma power and prevented ketamine's inhibitory effect on firing rates. Results provide new evidence that ketamine differentially modulates spiking and gamma power in MD thalamus and mPFC, supporting a potential role for both

  9. Proton MR spectroscopic imaging of basal ganglia and thalamus in neurofibromatosis type 1: correlation with T2 hyperintensities

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    Barbier, Charlotte; Barantin, Laurent [CHRU and Tours University, Department of Neuroradiology, Tours (France); Chabernaud, Camille [CHRU and Tours University et INSERM U930, Department of Pediatric Neurology, Tours (France); Bertrand, Philippe [CHRU and Tours University, Department of Radiology, Tours (France); Sembely, Catherine; Sirinelli, Dominique [CHRU and Tours University, Department of Pediatric Radiology, Tours (France); Castelnau, Pierre [CHRU and Tours University et INSERM U930, Department of Pediatric Neurology, Tours (France); CHRU and Tours University et INSERM U930, Tours (France); Neurologie Pediatrique and INSERM U930, Hopital d' Enfants Gatien de Clocheville, Tours cedex 09 (France); Cottier, Jean-Philippe [CHRU and Tours University, Department of Neuroradiology, Tours (France); CHRU and Tours University et INSERM U930, Tours (France)

    2011-02-15

    Neurofibromatosis type 1 (NF1) is frequently associated with hyperintense lesions on T2-weighted images called ''unidentified bright objects'' (UBO). To better characterize the functional significance of UBO, we investigate the basal ganglia and thalamus using spectroscopic imaging in children with NF1 and compare the results to anomalies observed on T2-weighted images. Magnetic resonance (MR) data of 25 children with NF1 were analyzed. On the basis of T2-weighted images analysis, two groups were identified: one with normal MR imaging (UBO- group; n = 10) and one with UBO (UBO+ group; n = 15). Within the UBO+ group, a subpopulation of patients (n = 5) only had lesions of the basal ganglia. We analyzed herein seven regions of interest (ROIs) for each side: caudate nucleus, capsulo-lenticular region, lateral and posterior thalamus, thalamus (lateral and posterior voxels combined), putamen, and striatum. For each ROI, a spectrum of the metabolites and their ratio was obtained. Patients with abnormalities on T2-weighted images had significantly lower NAA/Cr, NAA/Cho, and NAA/mI ratios in the lateral right thalamus compared with patients with normal T2. These abnormal spectroscopic findings were not observed in capsulo-lenticular regions that had UBO but in the thalamus region that was devoid of UBO. Multivoxel spectroscopic imaging using short-time echo showed spectroscopic abnormalities in the right thalamus of NF1 patients harboring UBO, which were mainly located in the basal ganglia. This finding could reflect the anatomical and functional interactions of these regions. (orig.)

  10. The role of the thalamus in the human subcortical vestibular system.

    Science.gov (United States)

    Conrad, Julian; Baier, Bernhard; Dieterich, Marianne

    2014-01-01

    Most of our knowledge concerning central vestibular pathways is derived from animal studies while evidence of the functional importance and localization of these pathways in humans is less well defined. The termination of these pathways at the thalamic level in humans is even less known. In this review we summarize the findings concerning the central subcortical vestibular pathways in humans and the role of these structures in the central vestibular system with regard to anatomical localization and function. Also, we review the role of the thalamus in the pathogenesis of higher order sensory deficits such as spatial neglect, pusher syndrome or thalamic astasia and the correlation of these phenomena with findings of a vestibular tone imbalance at the thalamic level. By highlighting thalamic structures involved in vestibular signal processing and relating the different nomenclatures we hope to provide a base for future studies on thalamic sensory signal processing.

  11. Functional Neurosurgery in the Human Thalamus by Transcranial Magnetic Resonance Guided Focused Ultrasound

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    Werner, Beat; Morel, Anne; Jeanmonod, Daniel; Martin, Ernst

    2009-04-01

    Potential applications of Transcranial Magnetic Resonance guided Focused Ultrasound (TcMRgFUS) include treatment of functional brain disorders, such as Parkinson's disease, dystonia and tremor, neurogenic pain and tinnitus, neuropsychiatric disorders and epilepsy. In this study we demonstrate the feasibility of non-invasive TcMRgFUS ablation of clinically well established targets in the human thalamus that are currently accessed stereotactically by interventional strategies based on the concept of the thalamocortical dysrhythmia (TCD). Thermal hotspots suitable for clinical intervention were created successfully in anatomical preparations of human ex-vivo heads under pseudo clinical conditions. The hotspots could be positioned at the target locations as needed and local energy deposition was sufficient to create tissue ablation. Numerical simulations based on these experimental data predict that the acoustic energy needed to create ablative lesions in-vivo will be within limits that can safely applied.

  12. Organization and morphology of thalamocortical neurons of mouse ventral lateral thalamus.

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    Tlamsa, Aileen P; Brumberg, Joshua C

    2010-01-01

    The ventral lateral nucleus of the thalamus (VL) serves as a central integrative center for motor control, receiving inputs from the cerebellum, striatum, and cortex and projecting to the primary motor cortex. We aimed to determine the somatotopy and morphological features of the thalamocortical neurons within mouse VL. Retrograde tracing studies revealed that whisker-related VL neurons were found relatively anterior and medial to those labeled following injection of retrograde tracer into hindpaw motor areas. Simultaneous injections of fluorescent microspheres in both cortical regions did not result in double-labeled neurons in VL. Quantitative analysis of dendritic and somatic morphologies did not reveal any differences between hindpaw and whisker thalamocortical neurons within VL. The morphology of the thalamocortical neurons within mouse VL is similar to those in other mammals and suggests that mouse can be used as a model system for studying thalamocortical transformations within the motor system as well as plasticity following sensory deprivation or enrichment.

  13. Extrastriatal binding of [¹²³I]FP-CIT in the thalamus and pons

    DEFF Research Database (Denmark)

    Koch, Walter; Unterrainer, Marcus; Xiong, Guoming

    2014-01-01

    PURPOSE: Apart from binding to the dopamine transporter (DAT), [(123)I]FP-CIT shows moderate affinity for the serotonin transporter (SERT), allowing imaging of both monoamine transporters in a single imaging session in different brain areas. The aim of this study was to systematically evaluate...... extrastriatal binding (predominantly due to SERT) and its age and gender dependencies in a large cohort of healthy controls. METHODS: SPECT data from 103 healthy controls with well-defined criteria of normality acquired at 13 different imaging centres were analysed for extrastriatal binding using volumes...... of interest analysis for the thalamus and the pons. Data were examined for gender and age effects as well as for potential influence of striatal DAT radiotracer binding. RESULTS: Thalamic binding was significantly higher than pons binding. Partial correlations showed an influence of putaminal DAT binding...

  14. Behavioral and cognitive changes after early postnatal lesions of the rat mediodorsal thalamus.

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    Ouhaz, Zakaria; Ba-M'hamed, Saadia; Mitchell, Anna S; Elidrissi, Abdeslem; Bennis, Mohamed

    2015-10-01

    Early insults to the thalamus result in functional and/or structural abnormalities in the cerebral cortex. However, differences in behavioral and cognitive changes after early insult are not well characterized. The present study assessed whether early postnatal damage to mediodorsal nucleus of the thalamus (MD), reciprocally interconnected with the prefrontal cortex, causes behavioral and cognitive alterations in young adult rats. Rat pups at postnatal day 4 received bilateral electrolytic lesion of MD, or a MD Sham lesion or were anesthetized controls; on recovery they were returned to their mothers until weaning. Seven weeks later, all rats were tested with the following behavioral and cognitive paradigms: T-maze test, open field test, actimetry, elevated plus maze test, social interactions test and passive avoidance test. Rats with bilateral MD damage presented with disrupted recognition memory, deficits in shifting response rules, significant hypoactivity, increased anxiety-like behavior, deficits in learning associations as well as decreased locomotor activity, and reduced social interactions compared to MD Sham lesion and anesthetized Control rats. The lesion also caused significant decreases in pyramidal cell density in three frontal cortex regions: medial infralimbic cortex, dorsolateral anterior cortex, and cingulate Cg1 cortex. The present findings suggest a functional role for MD in the postnatal maturation of affective behavior. Further some of the behavioral and cognitive alterations observed in these young adult rats after early MD lesion are reminiscent of those present in major psycho-affective disorders, such as schizophrenia in humans. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Open-loop organization of thalamic reticular nucleus and dorsal thalamus: a computational model.

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    Willis, Adam M; Slater, Bernard J; Gribkova, Ekaterina D; Llano, Daniel A

    2015-10-01

    The thalamic reticular nucleus (TRN) is a shell of GABAergic neurons that surrounds the dorsal thalamus. Previous work has shown that TRN neurons send GABAergic projections to thalamocortical (TC) cells to form reciprocal, closed-loop circuits. This has led to the hypothesis that the TRN is responsible for oscillatory phenomena, such as sleep spindles and absence seizures. However, there is emerging evidence that open-loop circuits are also found between TRN and TC cells. The implications of open-loop configurations are not yet known, particularly when they include time-dependent nonlinearities in TC cells such as low-threshold bursting. We hypothesized that low-threshold bursting in an open-loop circuit could be a mechanism by which the TRN could paradoxically enhance TC activation, and that enhancement would depend on the relative timing of TRN vs. TC cell stimulation. To test this, we modeled small circuits containing TC neurons, TRN neurons, and layer 4 thalamorecipient cells in both open- and closed-loop configurations. We found that open-loop TRN stimulation, rather than universally depressing TC activation, increased cortical output across a broad parameter space, modified the filter properties of TC neurons, and altered the mutual information between input and output in a frequency-dependent and T-type calcium channel-dependent manner. Therefore, an open-loop model of TRN-TC interactions, rather than suppressing transmission through the thalamus, creates a tunable filter whose properties may be modified by outside influences onto the TRN. These simulations make experimentally testable predictions about the potential role for the TRN for flexible enhancement of cortical activation. Copyright © 2015 the American Physiological Society.

  16. Deep arteriovenous malformations in the Basal Ganglia, thalamus, and insula: microsurgical management, techniques, and results.

    Science.gov (United States)

    Potts, Matthew B; Young, William L; Lawton, Michael T

    2013-09-01

    Arteriovenous malformations (AVMs) in the basal ganglia, thalamus, and insula are considered inoperable given their depth, eloquence, and limited surgical exposure. Although many neurosurgeons opt for radiosurgery or observation, others have challenged the belief that deep AVMs are inoperable. Further discussion of patient selection, technique, and multimodality management is needed. To describe and discuss the technical considerations of microsurgical resection for deep-seated AVMs. Patients with deep AVMs who underwent surgery during a 14-year period were reviewed through the use of a prospective AVM registry. Microsurgery was performed in 48 patients with AVMs in the basal ganglia (n=10), thalamus (n=13), or insula (n=25). The most common Spetzler-Martin grade was III- (68%). Surgical approaches included transsylvian (67%), transcallosal (19%), and transcortical (15%). Complete resection was achieved in 34 patients (71%), and patients with incomplete resection were treated with radiosurgery. Forty-five patients (94%) were improved or unchanged (mean follow-up, 1.6 years). This experience advances the notion that select deep AVMs may be operable lesions. Patients were highly selected for small size, hemorrhagic presentation, young age, and compactness-factors embodied in the Spetzler-Martin and Supplementary grading systems. Overall, 10 different approaches were used, exploiting direct, transcortical corridors created by hemorrhage or maximizing anatomic corridors through subarachnoid spaces and ventricles that minimize brain transgression. The same cautious attitude exercised in selecting patients for surgery was also exercised in deciding extent of resection, opting for incomplete resection and radiosurgery more than with other AVMs to prioritize neurological outcomes.

  17. Reduced noradrenaline, but not dopamine and serotonin in motor thalamus of the MPTP primate: relation to severity of parkinsonism.

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    Pifl, Christian; Hornykiewicz, Oleh; Blesa, Javier; Adánez, Rebeca; Cavada, Carmen; Obeso, José A

    2013-06-01

    We recently found severe noradrenaline deficits throughout the thalamus of patients with Parkinson's disease [C. Pifl, S. J. Kish and O. Hornykiewicz Mov Disord. 27, 2012, 1618.]. As this noradrenaline loss was especially severe in nuclei of the motor thalamus normally transmitting basal ganglia motor output to the cortex, we hypothesized that this noradrenaline loss aggravates the motor disorder of Parkinson's disease. Here, we analysed noradrenaline, dopamine and serotonin in motor (ventrolateral and ventroanterior) and non-motor (mediodorsal, centromedian, ventroposterior lateral and reticular) thalamic nuclei in MPTP-treated monkeys who were always asymptomatic; who recovered from mild parkinsonism; and monkeys with stable, either moderate or severe parkinsonism. We found that only the symptomatic parkinsonian animals had significant noradrenaline losses specifically in the motor thalamus, with the ventroanterior motor nucleus being affected only in the severe parkinsonian animals. In contrast, the striatal dopamine loss was identical in both the mild and severe symptom groups. MPTP-treatment had no significant effect on noradrenaline in non-motor thalamic nuclei or dopamine and serotonin in any thalamic subregion. We conclude that in the MPTP primate model, loss of noradrenaline in the motor thalamus may also contribute to the clinical expression of the parkinsonian motor disorder, corroborating experimentally our hypothesis on the role of thalamic noradrenaline deficit in Parkinson's disease. © 2013 International Society for Neurochemistry.

  18. Sporadic fatal insomnia with spongiform degeneration in the thalamus and widespread PrPSc deposits in the brain.

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    Piao, Yue-Shan; Kakita, Akiyoshi; Watanabe, Hiroyuki; Kitamoto, Tetsuyuki; Takahashi, Hitoshi

    2005-06-01

    We report a case of human prion disease of 29 months duration in a 74-year-old Japanese man. The disease started with progressive sleeplessness and dementia. MRI showed gradually progressive cerebral atrophy. Neuronal loss, spongiform change and gliosis were evident in the thalamus and cerebral cortex, as well as in the striatum and amygdaloid nucleus. In the cerebellar cortex, mild-to-moderate depletion of Pukinje cells and spongiform change were observed. Mild neuronal loss in the inferior olivary nucleus was also seen. Immunohistochemistry revealed widespread perivacuolar deposits of abnormal prion protein (PrPsc) in the cerebral cortex, thalamus, basal ganglia, and brainstem, and minimal plaque-like deposits of PrPSc in the cerebellar cortex. In the cerebellar plaque-like deposits, the presence of amyloid fibrils was confirmed ultrastructurally. The entire pathology appeared to lie halfway between those of CJD and fatal insomnia, and further demonstrated the relationship between spongiform degeneration and PrPSc deposits, especially in the diseased thalamus. By immunoblotting, the thalamus was shown to contain the lowest amount of PrPSc among the brain regions examined. The PrPSc of type 2, in which the ratio of the three glycoforms was compatible with that of sporadic fatal insomnia (MM2-thalamic variant) reported previously, was also demonstrated. Analysis of the prion protein gene (PRNP) showed no mutation, and homozygosity for methionine at codon 129. In conclusion, we considered that this patient had been suffering from sporadic, pathologically atypical fatal insomnia.

  19. 2-Cl-MGV-1 Ameliorates Apoptosis in the Thalamus and Hippocampus and Cognitive Deficits After Cortical Infarct in Rats.

    Science.gov (United States)

    Chen, Yicong; Veenman, Leo; Singh, Sukhdev; Ouyang, Fubing; Liang, Jiahui; Huang, Weixian; Marek, Ilan; Zeng, Jinsheng; Gavish, Moshe

    2017-11-16

    Focal cortical infarction causes neuronal apoptosis in the ipsilateral nonischemic thalamus and hippocampus, which is potentially associated with poststroke cognitive deficits. TSPO (translocator protein) is critical in regulating mitochondrial apoptosis pathways. We examined the effects of the novel TSPO ligand 2-(2-chlorophenyl)quinazolin-4-yl dimethylcarbamate (2-Cl-MGV-1) on poststroke cognitive deficits, neuronal mitochondrial apoptosis, and secondary damage in the ipsilateral thalamus and hippocampus after cortical infarction. One hundred fourteen hypertensive rats underwent successful distal middle cerebral artery occlusion (n=76) or sham procedures (n=38). 2-Cl-MGV-1 or dimethyl sulfoxide as vehicle was administrated 2 hours after distal middle cerebral artery occlusion and then for 6 or 13 days (n=19 per group). Spatial learning and memory were tested using the Morris water maze. Secondary degeneration and mitochondrial apoptosis in the thalamus and hippocampus were assessed using Nissl staining, immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick end labeling, JC-1 staining, and immunoblotting 7 and 14 days after surgery. Infarct volumes did not significantly differ between the vehicle and 2-Cl-MGV-1 groups. There were more neurons and fewer glia in the ipsilateral thalamus and hippocampus in the vehicle groups than in the sham-operated group 7 and 14 days post-distal middle cerebral artery occlusion. 2-Cl-MGV-1 significantly ameliorated spatial cognitive impairment and decreased neuronal death and glial activation when compared with vehicle treatment (P<0.05). The collapse of mitochondrial transmembrane potential and cytoplasmic release of apoptosis-inducing factors and cytochrome c was prevented within the thalamus. Caspase cleavage and the numbers of terminal deoxynucleotidyl transferase dUTP nick end labeling(+) or Nissl atrophic cells were reduced within the thalamus and hippocampus. This was accompanied by upregulation of B

  20. Disrupted Thalamus White Matter Anatomy and Posterior Default Mode Network Effective Connectivity in Amnestic Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Thomas Alderson

    2017-11-01

    Full Text Available Alzheimer’s disease (AD and its prodromal state amnestic mild cognitive impairment (aMCI are characterized by widespread abnormalities in inter-areal white matter fiber pathways and parallel disruption of default mode network (DMN resting state functional and effective connectivity. In healthy subjects, DMN and task positive network interaction are modulated by the thalamus suggesting that abnormal task-based DMN deactivation in aMCI may be a consequence of impaired thalamo-cortical white matter circuitry. Thus, this article uses a multimodal approach to assess white matter integrity between thalamus and DMN components and associated effective connectivity in healthy controls (HCs relative to aMCI patients. Twenty-six HC and 20 older adults with aMCI underwent structural, functional and diffusion MRI scanning using the high angular resolution diffusion-weighted acquisition protocol. The DMN of each subject was identified using independent component analysis (ICA and resting state effective connectivity was calculated between thalamus and DMN nodes. White matter integrity changes between thalamus and DMN were investigated with constrained spherical deconvolution (CSD tractography. Significant structural deficits in thalamic white matter projection fibers to posterior DMN components posterior cingulate cortex (PCC and lateral inferior parietal lobe (IPL were identified together with significantly reduced effective connectivity from left thalamus to left IPL. Crucially, impaired thalamo-cortical white matter circuitry correlated with memory performance. Disrupted thalamo-cortical structure was accompanied by significant reductions in IPL and PCC cortico-cortical effective connectivity. No structural deficits were found between DMN nodes. Abnormal posterior DMN activity may be driven by changes in thalamic white matter connectivity; a view supported by the close anatomical and functional association of thalamic nuclei effected by AD pathology and

  1. State Dependency of Chemosensory Coding in the Gustatory Thalamus (VPMpc) of Alert Rats.

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    Liu, Haixin; Fontanini, Alfredo

    2015-11-25

    The parvicellular portion of the ventroposteromedial nucleus (VPMpc) is the part of the thalamus that processes gustatory information. Anatomical evidence shows that the VPMpc receives ascending gustatory inputs from the parabrachial nucleus (PbN) in the brainstem and sends projections to the gustatory cortex (GC). Although taste processing in PbN and GC has been the subject of intense investigation in behaving rodents, much less is known on how VPMpc neurons encode gustatory information. Here we present results from single-unit recordings in the VPMpc of alert rats receiving multiple tastants. Thalamic neurons respond to taste with time-varying modulations of firing rates, consistent with those observed in GC and PbN. These responses encode taste quality as well as palatability. Comparing responses to tastants either passively delivered, or self-administered after a cue, unveiled the effects of general expectation on taste processing in VPMpc. General expectation led to an improvement of taste coding by modulating response dynamics, and single neuron ability to encode multiple tastants. Our results demonstrate that the time course of taste coding as well as single neurons' ability to encode for multiple qualities are not fixed but rather can be altered by the state of the animal. Together, the data presented here provide the first description that taste coding in VPMpc is dynamic and state-dependent. Over the past years, a great deal of attention has been devoted to understanding taste coding in the brainstem and cortex of alert rodents. Thanks to this research, we now know that taste coding is dynamic, distributed, and context-dependent. Alas, virtually nothing is known on how the gustatory thalamus (VPMpc) processes gustatory information in behaving rats. This manuscript investigates taste processing in the VPMpc of behaving rats. Our results show that thalamic neurons encode taste and palatability with time-varying patterns of activity and that thalamic coding

  2. Causal Evidence from Humans for the Role of Mediodorsal Nucleus of the Thalamus in Working Memory.

    Science.gov (United States)

    Peräkylä, Jari; Sun, Lihua; Lehtimäki, Kai; Peltola, Jukka; Öhman, Juha; Möttönen, Timo; Ogawa, Keith H; Hartikainen, Kaisa M

    2017-12-01

    The mediodorsal nucleus of the thalamus (MD), with its extensive connections to the lateral pFC, has been implicated in human working memory and executive functions. However, this understanding is based solely on indirect evidence from human lesion and imaging studies and animal studies. Direct, causal evidence from humans is missing. To obtain direct evidence for MD's role in humans, we studied patients treated with deep brain stimulation (DBS) for refractory epilepsy. This treatment is thought to prevent the generalization of a seizure by disrupting the functioning of the patient's anterior nuclei of the thalamus (ANT) with high-frequency electric stimulation. This structure is located superior and anterior to MD, and when the DBS lead is implanted in ANT, tip contacts of the lead typically penetrate through ANT into the adjoining MD. To study the role of MD in human executive functions and working memory, we periodically disrupted and recovered MD's function with high-frequency electric stimulation using DBS contacts reaching MD while participants performed a cognitive task engaging several aspects of executive functions. We hypothesized that the efficacy of executive functions, specifically working memory, is impaired when the functioning of MD is perturbed by high-frequency stimulation. Eight participants treated with ANT-DBS for refractory epilepsy performed a computer-based test of executive functions while DBS was repeatedly switched ON and OFF at MD and at the control location (ANT). In comparison to stimulation of the control location, when MD was stimulated, participants committed 2.26 times more errors in general (total errors; OR = 2.26, 95% CI [1.69, 3.01]) and 2.86 times more working memory-related errors specifically (incorrect button presses; OR = 2.88, CI [1.95, 4.24]). Similarly, participants committed 1.81 more errors in general ( OR = 1.81, CI [1.45, 2.24]) and 2.08 times more working memory-related errors ( OR = 2.08, CI [1.57, 2.75]) in

  3. Mean diffusivity of basal ganglia and thalamus specifically associated with motivational states among mood states.

    Science.gov (United States)

    Takeuchi, Hikaru; Taki, Yasuyuki; Sekiguchi, Atsushi; Nouchi, Rui; Kotozaki, Yuka; Nakagawa, Seishu; Miyauchi, Carlos Makoto; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

    2017-03-01

    Previously, we proposed that the mean diffusivity (MD), a measure of diffusion tensor imaging (DTI) in areas of the dopaminergic system (MDDS), is associated with motivation. In this study, we tested if and how the motivational state is associated with MD in comparison with other mood states. We also tested the associations of these mood states with multiple cognitive functions. We examined these issues in 766 right-handed healthy young adults. We employed analyses of MD and a psychological measure of the profile of mood states (POMS) as well as multiple cognitive functions. We detected associations between the higher Vigor subscale of POMS and lower MD in the right globus pallidum, right putamen to right posterior insula, right caudate body, and right thalamus, and these associations were highly specific to the Vigor subscale. Similarly, the association of the motivational state with creativity measured by divergent thinking (CMDT) was rather specific and prominent compared with that of the other mood states and cognitive functions. In conclusion, when affective states are finely divided, only the motivational state is associated with MD in the areas related to the dopaminergic system, and psychological mechanisms that had been associated with dopaminergic system (CMDT). These results suggest that these mechanisms specifically contribute to the motivational state and not to the other states, such as depression and anxiety.

  4. Inhibitory synaptic transmission from the substantia nigra pars reticulata to the ventral medial thalamus in mice.

    Science.gov (United States)

    Kase, Daisuke; Uta, Daisuke; Ishihara, Hiromi; Imoto, Keiji

    2015-08-01

    The cortico-basal ganglia-thalamic loop circuit is involved in variety of motor, association and limbic functions. The basal ganglia receive neural information from various areas of the cerebral cortex and transfer them back to the frontal and motor cortex via the ventral medial (VM), and the anterior-ventral lateral thalamic complex. The projection from the basal ganglia to the thalamus is GABAergic, and, therefore, the output from the basal ganglia cannot directly evoke excitation in the thalamic nuclei. The mechanism underlying the information transfer via the inhibitory projection remains unclear. To address this issue, we recorded electrophysiological properties of nigro-thalamic synapses from the VM neuron. We developed a nigro-thalamic slice preparation, in which the projection from the substantia nigra pars reticulata (SNr) to VM nucleus is stored, to enable the selective activation of the projection from the SNr. We characterized synaptic properties and membrane properties of the VM neuron, and developed a VM neuron model to simulate the impacts of SNr inputs on VM neuron activity. Neural simulation suggested that the inhibitory projection from SNr can control neural activity in two ways: a disinhibition from the spontaneous nigral inhibition and a β-band synchronization evoked by combination of excitation and inhibition of SNr activity. Copyright © 2015 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  5. Inhibition of NMDARs in the nucleus reticularis of the thalamus produces delta frequency bursting

    Directory of Open Access Journals (Sweden)

    Yuchun Zhang

    2009-11-01

    Full Text Available Injection of NMDAR antagonist into the thalamus can produce delta frequency EEG oscillations in the thalamocortical system. It is surprising that an antagonist of an excitatory neurotransmitter should trigger such activity, and the mechanism is unknown. One hypothesis is that the antagonist blocks excitation of GABAergic cells, thus producing disinhibition. To test this hypothesis, we investigated the effect of NMDAR antagonist (APV on cells of the nucleus reticularis (nRT in rat brain slices, a thalamic nucleus that can serve as a pacemaker for thalamocortical delta oscillations and that is composed entirely of GABAergic neurons. We found, unexpectedly, that nRT cells are hyperpolarized by APV. This occurs because these cells have an unusual form of NMDAR (probably NR2C that contributes inward current at resting potential in response to ambient glutamate. The hyperpolarization produced by APV is sufficient to deinactivate T-type calcium channels, and these trigger rhythmic bursting at delta frequency. The APV-induced delta frequency bursting is abolished by dopamine D2 receptor antagonist, indicating that dopamine and NMDAR antagonist work synergistically to stimulate delta frequency bursting. Our results have significant implications concerning the electrophysiological basis of schizophrenia and bring together the NMDAR hypofunction, dopamine, and GABA theories of the disease. Our results suggest that NMDAR hypofunction and dopamine work synergistically on the GABAergic cells of the nRT to generate the delta frequency EEG oscillations, a thalamocortical dysrhythmia (TCD in the awake state that is an established abnormality in schizophrenia.

  6. Barreloid Borders and Neuronal Activity Shape Panglial Gap Junction-Coupled Networks in the Mouse Thalamus.

    Science.gov (United States)

    Claus, Lena; Philippot, Camille; Griemsmann, Stephanie; Timmermann, Aline; Jabs, Ronald; Henneberger, Christian; Kettenmann, Helmut; Steinhäuser, Christian

    2018-01-01

    The ventral posterior nucleus of the thalamus plays an important role in somatosensory information processing. It contains elongated cellular domains called barreloids, which are the structural basis for the somatotopic organization of vibrissae representation. So far, the organization of glial networks in these barreloid structures and its modulation by neuronal activity has not been studied. We have developed a method to visualize thalamic barreloid fields in acute slices. Combining electrophysiology, immunohistochemistry, and electroporation in transgenic mice with cell type-specific fluorescence labeling, we provide the first structure-function analyses of barreloidal glial gap junction networks. We observed coupled networks, which comprised both astrocytes and oligodendrocytes. The spread of tracers or a fluorescent glucose derivative through these networks was dependent on neuronal activity and limited by the barreloid borders, which were formed by uncoupled or weakly coupled oligodendrocytes. Neuronal somata were distributed homogeneously across barreloid fields with their processes running in parallel to the barreloid borders. Many astrocytes and oligodendrocytes were not part of the panglial networks. Thus, oligodendrocytes are the cellular elements limiting the communicating panglial network to a single barreloid, which might be important to ensure proper metabolic support to active neurons located within a particular vibrissae signaling pathway. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Roles of prefrontal cortex and paraventricular thalamus in affective and mechanical components of visceral nociception.

    Science.gov (United States)

    Jurik, Angela; Auffenberg, Eva; Klein, Sabine; Deussing, Jan M; Schmid, Roland M; Wotjak, Carsten T; Thoeringer, Christoph K

    2015-12-01

    Visceral pain represents a major clinical challenge in the management of many gastrointestinal disorders, eg, pancreatitis. However, cerebral neurobiological mechanisms underlying visceral nociception are poorly understood. As a representative model of visceral nociception, we applied cerulein hyperstimulation in C57BL6 mice to induce acute pancreatitis and performed a behavioral test battery and c-Fos staining of brains. We observed a specific pain phenotype and a significant increase in c-Fos immunoreactivity in the paraventricular nucleus of the thalamus (PVT), the periaqueductal gray, and the medial prefrontal cortex (mPFC). Using neuronal tracing, we observed projections of the PVT to cortical layers of the mPFC with contacts to inhibitory GABAergic neurons. These inhibitory neurons showed more activation after cerulein treatment suggesting thalamocortical "feedforward inhibition" in visceral nociception. The activity of neurons in pancreatitis-related pain centers was pharmacogenetically modulated by designer receptors exclusively activated by designer drugs, selectively and cell type specifically expressed in target neurons using adeno-associated virus-mediated gene transfer. Pharmacogenetic inhibition of PVT but not periaqueductal gray neurons attenuated visceral pain and induced an activation of the descending inhibitory pain pathway. Activation of glutamatergic principle neurons in the mPFC, but not inhibitory neurons, also reversed visceral nociception. These data reveal novel insights into central pain processing that underlies visceral nociception and may trigger the development of novel, potent centrally acting analgesic drugs.

  8. Degeneration of paramedian nuclei in the thalamus induces Holmes tremor in a case of artery of Percheron infarction.

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    Wei, Tz-Shiang; Hsu, Chun-Sheng; Lee, Yu-Chun; Chang, Shin-Tsu

    2017-11-01

    Holmes' tremor is an uncommon neurologic disorder following brain insults, and its pathogenesis is undefined. The interruption of the dento-rubro-thalamic tract and secondary deterioration of the nigrostriatal pathway are both required to initiate Holmes' tremor. We used nuclear medicine imaging tools to analyze a patient with concurrent infarction in different zones of each side of the thalamus. Finding whether the paramedian nuclear groups of the thalamus were injured was a decisive element for developing Holmes' tremor. A 36-year-old woman was admitted to our department due to a bilateral paramedian thalamic infarction. Seven months after the stroke, a unilaterally involuntary trembling with irregularly wavering motions occurring in both her left hand and forearm. Based on the distinct features of the unilateral coarse tremor and the locations of the lesions on the magnetic resonance imaging (MRI), the patient was diagnosed with bilateral paramedian thalamic infarction complicated with a unilateral Holmes' tremor. The patient refused our recommendation of pharmacological treatment with levodopa and other dopamine agonists based on personal reasons and was only willing to accept physical and occupational training programs at our outpatient clinic. We utilized serial anatomic and functional neuroimaging of the brain to survey the neurologic deficit. A brain magnetic resonance imaging showed unequal recovery on each side of the thalamus. The residual lesion appeared larger in the right-side thalamus and had gathered in the paramedian area. A brain perfusion single-photon emission computed tomography (SPECT) revealed that the post-stroke hypometabolic changes were not only in the right-side thalamus but also in the right basal ganglion, which was anatomically intact. Furthermore, the brain Technetium-99m-labeled tropanes as a dopamine transporter imaging agents scan ( Tc-TRODAT-1) displayed a secondary reduction of dopamine transporters in the right nigrostriatal

  9. Complex Multiplexing of Reward-Cue- and Licking-Movement-Related Activity in Single Midline Thalamus Neurons.

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    Li, Yuhong; Lindemann, Christoph; Goddard, Matthew J; Hyland, Brian I

    2016-03-23

    Midline thalamus is implicated in linking visceral and exteroceptive sensory information with behavior. However, whether neuronal activity is modulated with temporal precision by cues and actions in real time is unknown. Using single-neuron recording and a Pavlovian visual-cue/liquid-reward association task in rats, we discovered phasic responses to sensory cues, appropriately timed to modify information processing in output targets, as well as tonic modulations within and between trials that were differentially reward modulated, which may have distinct arousal functions. Many of the cue-responsive neurons also responded to repetitive licks, consistent with sensorimotor integration. Further, some lick-related neurons were activated only by the first rewarded lick and only if that lick were also part of a conditioned response sequence initiated earlier, consistent with binding action decisions to their ensuing outcome. This rich repertoire of responses provides electrophysiological evidence for midline thalamus as a site of complex information integration for reward-mediated behavior. Disparate brain circuits are involved in sensation, movement, and reward information. These must interact in order for the relationships between cues, actions, and outcomes to be learned. We found that responses of single neurons in midline thalamus to sensory cues are increased when associated with reward. This output may amplify similar signals generated in parallel by the dopamine system. In addition, some neurons coded a three-factor decision in which the neuron fired only if there was a movement, if it was the first one after the reward becoming available, and if it was part of a sequence triggered in response to a preceding cue. These data highlight midline thalamus as an important node integrating multiple types of information for linking sensation, actions, and rewards. Copyright © 2016 the authors 0270-6474/16/363567-12$15.00/0.

  10. Connectivity-based parcellation of the thalamus explains specific cognitive and behavioural symptoms in patients with bilateral thalamic infarct.

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    Laura Serra

    Full Text Available A novel approach based on diffusion tractography was used here to characterise the cortico-thalamic connectivity in two patients, both presenting with an isolated bilateral infarct in the thalamus, but exhibiting partially different cognitive and behavioural profiles. Both patients (G.P. and R.F. had a pervasive deficit in episodic memory, but only one of them (R.F. suffered also from a dysexecutive syndrome. Both patients had an MRI scan at 3T, including a T1-weighted volume. Their lesions were manually segmented. T1-volumes were normalised to standard space, and the same transformations were applied to the lesion masks. Nineteen healthy controls underwent a diffusion-tensor imaging (DTI scan. Their DTI data were normalised to standard space and averaged. An atlas of Brodmann areas was used to parcellate the prefrontal cortex. Probabilistic tractography was used to assess the probability of connection between each voxel of the thalamus and a set of prefrontal areas. The resulting map of corticothalamic connections was superimposed onto the patients' lesion masks, to assess whether the location of the thalamic lesions in R.F. (but not in G. P. implied connections with prefrontal areas involved in dysexecutive syndromes. In G.P., the lesion fell within areas of the thalamus poorly connected with prefrontal areas, showing only a modest probability of connection with the anterior cingulate cortex (ACC. Conversely, R.F.'s lesion fell within thalamic areas extensively connected with the ACC bilaterally, with the right dorsolateral prefrontal cortex, and with the left supplementary motor area. Despite a similar, bilateral involvement of the thalamus, the use of connectivity-based segmentation clarified that R.F.'s lesions only were located within nuclei highly connected with the prefrontal cortical areas, thus explaining the patient's frontal syndrome. This study confirms that DTI tractography is a useful tool to examine in vivo the effect of focal

  11. Adolescents with current major depressive disorder show dissimilar patterns of age-related differences in ACC and thalamus

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    Cindy C. Hagan

    2015-01-01

    Conclusions: The depressed adolescent brain shows dissimilar age-related and symptom-sensitive patterns of GMV differences compared with controls. The thalamus and ACC may comprise neural markers for detecting these effects in youth. Further investigations therefore need to take both age and level of current symptoms into account when disaggregating antecedent neural vulnerabilities for MDD from the effects of MDD on the developing brain.

  12. Connectivity-based parcellation of the thalamus explains specific cognitive and behavioural symptoms in patients with bilateral thalamic infarct.

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    Serra, Laura; Cercignani, Mara; Carlesimo, Giovanni A; Fadda, Lucia; Tini, Nadia; Giulietti, Giovanni; Caltagirone, Carlo; Bozzali, Marco

    2014-01-01

    A novel approach based on diffusion tractography was used here to characterise the cortico-thalamic connectivity in two patients, both presenting with an isolated bilateral infarct in the thalamus, but exhibiting partially different cognitive and behavioural profiles. Both patients (G.P. and R.F.) had a pervasive deficit in episodic memory, but only one of them (R.F.) suffered also from a dysexecutive syndrome. Both patients had an MRI scan at 3T, including a T1-weighted volume. Their lesions were manually segmented. T1-volumes were normalised to standard space, and the same transformations were applied to the lesion masks. Nineteen healthy controls underwent a diffusion-tensor imaging (DTI) scan. Their DTI data were normalised to standard space and averaged. An atlas of Brodmann areas was used to parcellate the prefrontal cortex. Probabilistic tractography was used to assess the probability of connection between each voxel of the thalamus and a set of prefrontal areas. The resulting map of corticothalamic connections was superimposed onto the patients' lesion masks, to assess whether the location of the thalamic lesions in R.F. (but not in G. P.) implied connections with prefrontal areas involved in dysexecutive syndromes. In G.P., the lesion fell within areas of the thalamus poorly connected with prefrontal areas, showing only a modest probability of connection with the anterior cingulate cortex (ACC). Conversely, R.F.'s lesion fell within thalamic areas extensively connected with the ACC bilaterally, with the right dorsolateral prefrontal cortex, and with the left supplementary motor area. Despite a similar, bilateral involvement of the thalamus, the use of connectivity-based segmentation clarified that R.F.'s lesions only were located within nuclei highly connected with the prefrontal cortical areas, thus explaining the patient's frontal syndrome. This study confirms that DTI tractography is a useful tool to examine in vivo the effect of focal lesions on

  13. Giant cavernous malformation in the ventrolateral midbrain with extension into the thalamus: a case report of a paramedian supracerebellar transtentorial approach.

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    Duan, Hongzhou; Hara, Yosuke; Goto, Tetsuya; Chiba, Akihiro; Hongo, Kazuhiro

    2016-08-01

    Cavernous malformations (CMs) of the midbrain and thalamus are relatively rare and particularly difficult to be resected given their location in eloquent tissues. Here, we report a case of a 14-year-old boy who experienced repeated and progressive right hemiparesis. Image examinations showed a gradually enlarged CM originated in the left ventrolateral midbrain extending to the left thalamus with repeated hemorrhage. By performing a paramedian supracerebellar transtentorial approach, the CM was totally removed, and the patient recovered without any new neurological deficit. The authors' experience suggests that this approach is eminent in treating giant lesions involving the ventrolateral midbrain and thalamus.

  14. Proton spectroscopy of the thalamus in a homogeneous sample of patients with easy-to-control juvenile myoclonic epilepsy

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    Leite, Claudia da Costa; Valente, Kette Dualibi Ramos; Fiore, Lia Arno; Otaduy, Maria Concepcion Garcia, E-mail: claudia.leite@hc.fm.usp.br [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina

    2017-09-15

    Objective: Juvenile myoclonic epilepsy (JME) is a subtype of genetically determined generalized epilepsy that does not present abnormalities on conventional magnetic resonance imaging. The aim of this study was to identify metabolic alterations in the thalamus in a clinically homogeneous sample of patients with easy-to-control JME, using short-echo time proton magnetic resonance spectroscopy (MRS). Materials and Methods: We performed single-voxel (2 cm × 2 cm × 2 cm), short-echo time (TE = 35 ms) proton MRS of the thalamus in 21 patients with JME and in 14 healthy age-matched controls. We quantified N-acetylaspartate (NAA), total NAA, creatine (Cr), choline, and myo-inositol (MI), as well as the sum of glutamate and glutamine signals, all scaled to internal water content, and we calculated metabolite ratios using Cr as a reference. Values of p < 0.05 were considered significant. Results: The MI level and the MI/Cr ratio were significantly lower in the thalami of patients diagnosed with JME than in those of the controls. Other metabolites and their ratios did not differ significantly between the two groups. Conclusion: In our sample of 21 JME patients, we identified lower levels of MI in the thalamus. No significant abnormalities were observed in the concentrations or ratios of other metabolites. (author)

  15. Functional Anatomy of the Thalamus as a Model of Integrated Structural and Functional Connectivity of the Human Brain In Vivo.

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    Mastropasqua, Chiara; Bozzali, Marco; Spanò, Barbara; Koch, Giacomo; Cercignani, Mara

    2015-07-01

    While methods of measuring non-invasively both, functional and structural brain connectivity are available, the degree of overlap between them is still unknown. In this paper this issue is addressed by investigating the connectivity pattern of a brain structure with many, well characterized structural connections, namely the thalamus. Diffusion-weighted and resting state (RS) functional MRI (fMRI) data were collected in a group of 38 healthy participants. Probabilistic tractography was performed to parcellate the thalamus into regions structurally connected to different cortical areas. The resulting regions were used as seeds for seed-based analysis of RS fMRI data. The tractographic parcellation was thus cross-validated against functional connectivity data by evaluating the overlap between the functional and structural thalamo-cortical connections originating from the parcellated regions. Our data show only a partial overall correspondence between structural and functional connections, in the same group of healthy individuals, thus suggesting that the two approaches provide complementary and not overlapping information. Future studies are warranted to extend the results we obtained in the thalamus to other structures, and to confirm that the mechanisms behind functional connectivity are more complex than just expressing structural connectivity.

  16. Role of Neurotrophins on Postnatal Neurogenesis in the Thalamus: Prenatal Exposure to Ethanol

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    Mooney, Sandra M.; Miller, Michael W.

    2011-01-01

    A second wave of neuronal generation occurs in the ventrobasal nucleus of the rat thalamus (VB) during the first three postnatal weeks. The present study tested the hypotheses (1) that postnatal neurogenesis in the VB is neurotrophin-regulated and (2) that ethanol-induced changes in this proliferation are mediated by neurotrophins. The first studies examined the effects of neurotrophins on the numbers of cycling cells in ex vivo preparations of the VB from three-day-old rats. The proportion of cycling (Ki-67-positive) VB cells was higher in cultured thalamic slices treated with neurotrophins than in controls. Interestingly, this increase occurred with nerve growth factor (NGF) alone or with a combination of NGF and brain-derived neurotrophic factor (BDNF), but not with BDNF alone. Based on these data, the VBs from young offspring of pregnant rats fed an ethanol-containing or an isocaloric non-alcoholic liquid diet were examined between postnatal day (P) 1 and P31. Studies used enzyme-linked immunosorbent assays and immunoblots to explore the effects of ethanol on the expression of neurotrophins, their receptors, and representative signaling proteins. Ethanol altered the expression of neurotrophins and receptors throughout the first postnatal month. Expression of NGF increased, but there was no change in the expression of BDNF. The high affinity receptors (TrkA and TrkB) were unchanged but ethanol decreased expression of the low affinity receptor, p75. One downstream signaling protein, extracellular signal-regulated kinase (ERK), decreased but Akt expression was unchanged. Thus, postnatal cell proliferation in the VB of young rat pups is neurotrophin-responsive and is affected by ethanol. PMID:21277941

  17. Lesions of the posterior paraventricular nucleus of the thalamus attenuate fear expression

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    Yonghui eLi

    2014-03-01

    Full Text Available The paraventricular nucleus of the thalamus (PVT has generated interest because of its strong projections to areas of the brain associated with the regulation of emotional behaviors. The posterior aspect of the PVT (pPVT is notable for its projection to the central nucleus of the amygdala which is essential for the expression of a conditioned fear response. The present study was done to determine if the pPVT is involved in the expression of fear by examining the effect of post-conditioning lesions of the pPVT. Male rats were trained to bar press for food pellets on a variable ratio schedule. Fear conditioning was done using auditory tones (30 s that co-terminate with footschocks (0.65 mA, 1.0 s. Rats were anesthetized 24 hours later and small bilateral electrolytic lesions of the pPVT were made. Fear expression to the tone was assessed using suppression of bar-pressing and freezing after one week of recovery from the surgical procedure. Small bilateral lesions of the pPVT increased bar-pressing for food and decreased freezing during the presentation of the conditioned tone. Lesions of the pPVT had no effect on fear extinction, fear conditioning to a novel tone, or the motivation for food as assessed using a progressive ratio schedule. The results of the experiment support a role for the pPVT in fear expression. In contrast, the pPVT does not appear to be involved in fear learning or extinction nor does it appear to play a role in the motivation of rats to bar press for food.

  18. Reduced GABA content in the motor thalamus during effective deep brain stimulation of the subthalamic nucleus

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    Alessandro eStefani

    2011-04-01

    Full Text Available Deep brain stimulation (DBS of the subthalamic nucleus (STN, in Parkinson’s disease (PD patients, is a well established therapeutic option, but its mechanisms of action are only partially known. In our previous study, the clinical transitions from OFF- to ON-state were not correlated with significant changes of GABA content inside GPi or substantia nigra reticulata.Here, biochemical effects of STN-DBS have been assessed in putamen (PUT, internal pallidus (GPi, and inside the antero-ventral thalamus (VA, the key station receiving pallidothalamic fibres. In ten advanced PD patients undergoing surgery, microdialysis samples were collected before and during STN-DBS. cGMP, an index of glutamatergic transmission, was measured in GPi and PUT by radioimmunoassay, whereas GABA from VA was measured by HPLC.During clinically effective STN-DBS, we found a significant decrease in GABA extracellular concentrations in VA (- 30%. Simultaneously, cGMP extracellular concentrations were enhanced in PUT (+200% and GPi (+481%. These findings support a thalamic dis-inhibition, in turn re-establishing a more physiological corticostriatal transmission, as the source of motor improvement. They indirectly confirm the relevance of patterning (instead of mere changes of excitability and suggest that a rigid interpretation of the standard model, at least when it indicates the hyperactive indirect pathway as key feature of hypokinetic signs, is unlikely to be correct. Finally, given the demonstration of a key role of VA in inducing clinical relief, locally administration of drugs modulating GABA transmission in thalamic nuclei could become an innovative therapeutic strategy.

  19. Surgical Approaches for Symptomatic Cerebral Cavernous Malformations of the Thalamus and Brainstem

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    Starke, Robert M.; Crowley, R. Webster; Liu, Kenneth C.

    2017-01-01

    Objective Surgical resection of thalamic and brainstem cerebral cavernous malformations (CCMs) is associated with significant operative morbidity, but it may be outweighed, in some cases, by the neurological damage from recurrent hemorrhage in these eloquent areas. The goals of this retrospective cohort study are to describe the technical nuances of surgical approaches and determine the postoperative outcomes for CCMs of the thalamus and brainstem. Materials and Methods We reviewed an institutional database of patients harboring thalamic or brainstem CCMs, who underwent surgical resection from 2010 to 2014. The baseline and follow-up neuroimaging and clinical findings of each patient and the operative details of each case were evaluated. Results A total of eight patients, including two with thalamic and six with brainstem CCMs, were included in the study cohort. All patients had progressive neurological deterioration from recurrent CCM hemorrhage, and the median modified Rankin Scale (mRS) at presentation was 3. The median CCM maximum diameter and volume were 1.7 cm and 1.8 cm3, respectively. The thalamic CCMs were resected using the anterior transcallosal transchoroidal and supracerebellar infratentorial approaches each in one case (13%). The brainstem CCMs were resected using the retrosigmoid and suboccipital trans-cerebellomedullary fissure approaches each in three cases (38%). After a median follow-up of 11.5 months, all patients were neurologically stable or improved, with a median mRS of 2. The rate of functional independence (mRS 0-2) was 63%. Conclusion Microneurosurgical techniques and approaches can be safely and effectively employed for the management of thalamic and brainstem CCMs in appropriately selected patients. PMID:28503485

  20. Organization of the Zone of Transition between the Pretectum and the Thalamus, with Emphasis on the Pretectothalamic Lamina

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    Emmanuel Márquez-Legorreta

    2016-08-01

    Full Text Available The zone of transition between the pretectum, derived from prosomere 1, and the thalamus, derived from prosomere 2, is structurally complex and its understanding has been hampered by cytoarchitectural and terminological confusion. Herein, using a battery of complementary morphological approaches, including cytoarchitecture, myeloarchitecture and the expression of molecular markers, we pinpoint the features or combination of features that best characterize each nucleus of the pretectothalamic transitional zone of the rat. Our results reveal useful morphological criteria to identify and delineate, with unprecedented precision, several [mostly auditory] nuclei of the posterior group of the thalamus, namely the pretectothalamic lamina (PTL; formerly known as the posterior limitans nucleus, the medial division of the medial geniculate body (MGBm, the suprageniculate nucleus (SG, and the ethmoid, posterior triangular and posterior nuclei of the thalamus. The PTL is a sparsely-celled and fiber rich flattened nucleus apposed to the lateral surface of the anterior pretectal nucleus that marks the border between the pretectum and the thalamus; this structure stains selectively with the Wisteria floribunda agglutinin (WFA, and is essentially immunonegative for the calcium binding protein parvalbumin. The MGBm, located medial to the ventral division of the medial geniculate body, can be unequivocally identified by the large size of many of its neurons, its dark immunostaining for parvalbumin, and its rather selective staining for WFA. The SG, which extends for a considerable caudorostral distance and deviates progressively from the MGB, is characterized by its peculiar cytoarchitecture, the paucity of myelinated fibers, and the conspicuous absence of staining for calretinin; indeed, in many calretinin-stained sections, the SG stands out as a blank spot. Because most of these nuclei are small and show unique anatomical relationships, the information provided

  1. Adolescents with current major depressive disorder show dissimilar patterns of age-related differences in ACC and thalamus.

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    Hagan, Cindy C; Graham, Julia M E; Tait, Roger; Widmer, Barry; van Nieuwenhuizen, Adrienne O; Ooi, Cinly; Whitaker, Kirstie J; Simas, Tiago; Bullmore, Edward T; Lennox, Belinda R; Sahakian, Barbara J; Goodyer, Ian M; Suckling, John

    2015-01-01

    There is little understanding of the neural system abnormalities subserving adolescent major depressive disorder (MDD). In a cross-sectional study we compare currently unipolar depressed with healthy adolescents to determine if group differences in grey matter volume (GMV) were influenced by age and illness severity. Structural neuroimaging was performed on 109 adolescents with current MDD and 36 healthy controls, matched for age, gender, and handedness. GMV differences were examined within the anterior cingulate cortex (ACC) and across the whole-brain. The effects of age and self-reported depressive symptoms were also examined in regions showing significant main or interaction effects. Whole-brain voxel based morphometry revealed no significant group differences. At the whole-brain level, both groups showed a main effect of age on GMV, although this effect was more pronounced in controls. Significant group-by-age interactions were noted: A significant regional group-by-age interaction was observed in the ACC. GMV in the ACC showed patterns of age-related differences that were dissimilar between adolescents with MDD and healthy controls. GMV in the thalamus showed an opposite pattern of age-related differences in adolescent patients compared to healthy controls. In patients, GMV in the thalamus, but not the ACC, was inversely related with self-reported depressive symptoms. The depressed adolescent brain shows dissimilar age-related and symptom-sensitive patterns of GMV differences compared with controls. The thalamus and ACC may comprise neural markers for detecting these effects in youth. Further investigations therefore need to take both age and level of current symptoms into account when disaggregating antecedent neural vulnerabilities for MDD from the effects of MDD on the developing brain.

  2. Consistent phosphenes generated by electrical microstimulation of the visual thalamus. An experimental approach for thalamic visual neuroprostheses

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    Fivos ePanetsos

    2011-07-01

    Full Text Available Most work on visual prostheses has centred on developing retinal or cortical devices. However, when retinal implants are not feasible, neuroprostheses could be implanted in the lateral geniculate nucleus of the thalamus (LGN, the intermediate relay station of visual information from the retina to the visual cortex (V1. The objective of the present study was to determine the types of artificial stimuli that when delivered to the visual thalamus can generate reliable responses of the cortical neurons similar to those obtained when the eye perceives a visual image. Visual stimuli {Si} were presented to one eye of an experimental animal and both, the thalamic {RThi} and cortical responses {RV1i} to such stimuli were recorded. Electrical patterns {RThi*} resembling {RThi} were then injected into the visual thalamus to obtain cortical responses {RV1i*} similar to {RV1i}. Visually- and electrically-generated V1 responses were compared.Results: During the course of this work we: (i characterised the response of V1 neurons to visual stimuli according to response magnitude, duration, spiking rate and the distribution of interspike intervals; (ii experimentally tested the dependence of V1 responses on stimulation parameters such as intensity, frequency, duration, etc. and determined the ranges of these parameters generating the desired cortical activity; (iii identified similarities between responses of V1 useful to compare the naturally and artificially generated neuronal activity of V1; and (iv by modifying the stimulation parameters, we generated artificial V1 responses similar to those elicited by visual stimuli.Generation of predictable and consistent phosphenes by means of artificial stimulation of the LGN is important for the feasibility of visual prostheses. Here we proved that electrical stimuli to the LGN can generate V1 neural responses that resemble those elicited by natural visual stimuli.

  3. DC electrical stimulation of the pretectal thalamus and its effects on the feeding behavior of the toad (Bufo bufo).

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    McConville, James; Laming, Peter R

    2007-06-01

    The feeding motivation of the common European common toad (Bufo bufo) can be quantified by the feeding sequence of arousal-orientation-approach-fixate-snap. Previous work has found that the optic tectum is an important structure responsible for the mediation of feeding behaviors, and combined electrical and visual stimulation of the optic tectum was found to increase the animals feeding behaviors. However, the pretectal thalamus has an inhibitory influence upon the optic tectum and its lesion results in disinhibited feeding behaviors. This suggests that feeding behavior of anurans is also subject to influence from the pretectal thalamus. Previous studies involving the application of DC stimulation to brain tissue has generated slow potential shifts and these shifts have been implicated in the modulation of the neural mechanisms associated with behavior. The current study investigated the application of DC stimulation to the diencephalon surface dorsal to the lateral posterodorsal pretectal thalamic nucleus in Bufo bufo, in order to assess effects on feeding motivation. The application of DC stimulation increased the incidence of avoidance behaviors to a visual prey stimulus while reducing the prey catching behavior component of approach, suggesting that the DC current applied to the pretectum increased the inhibition upon the feeding elements of the optic tectum. This can be explained by the generation of slow potential shifts.

  4. CT and SPECT in two-cell-pattern germinoma arising from a unilateral thalamus and a basal ganglion

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    Kikuchi, Kenji; Kamisato, Nobuo; Kowada, Masayoshi; Ogayama, Hiroyuki; Watanabe, Kazuo.

    1988-06-01

    A case of primary intracranial germ-cell tumor involving a unilateral thalamus and a basal ganglion is presented. A 15-year-old boy was referred to the hospital for an evaluation of right hemiparesis and diabetes insipidus. A CT scan showed a slightly hyperdense mass lesion involving the left thalamic and basal ganglionic regions. The mass was homogeneously enhanced after the intravenous administration of a contrast medium. Serial cerebral angiograms revealed an avascular mass lesion, and neither tumor vessels nor tumor stains were visualized. Single-photon emission CT (SPECT) revealed that the mean cerebral blood flow in the entire affected hemisphere decreased by 12 - 15 %. The tumor was biopsied by a left subtemporal approach using an operating microscope; the histological diagnosis was that of ''two-cell-pattern'' germinoma. Postoperatively the patient underwent cranial irradiation (53.5 Gy) over a period of six weeks. Subsequent CT scans showed a complete disappearance of the enhancing lesion at the left basal ganglion. Primary germ-cell tumors arising from the unilateral thalamus and basal ganglion, as reported in the literature, are reviewed, with special reference to their CT appearances; the possible mechanism of an extensive decrease in the mean hemispheric cerebral blood flow, as delineated by SPECT in the present case, is also discussed.

  5. Fast and Slow Inhibition in the Visual Thalamus Is Influenced by Allocating GABAA Receptors with Different γ Subunits

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    Zhiwen Ye

    2017-04-01

    Full Text Available Cell-type specific differences in the kinetics of inhibitory postsynaptic conductance changes (IPSCs are believed to impact upon network dynamics throughout the brain. Much attention has focused on how GABAA receptor (GABAAR α and β subunit diversity will influence IPSC kinetics, but less is known about the influence of the γ subunit. We have examined whether GABAAR γ subunit heterogeneity influences IPSC properties in the thalamus. The γ2 subunit gene was deleted from GABAARs selectively in the dorsal lateral geniculate nucleus (dLGN. The removal of the γ2 subunit from the dLGN reduced the overall spontaneous IPSC (sIPSC frequency across all relay cells and produced an absence of IPSCs in a subset of relay neurons. The remaining slower IPSCs were both insensitive to diazepam and zinc indicating the absence of the γ2 subunit. Because these slower IPSCs were potentiated by methyl-6,7-dimethoxy-4-ethyl-β-carboline-3-carboxylate (DMCM, we propose these IPSCs involve γ1 subunit-containing GABAAR activation. Therefore, γ subunit heterogeneity appears to influence the kinetics of GABAAR-mediated synaptic transmission in the visual thalamus in a cell-selective manner. We suggest that activation of γ1 subunit-containing GABAARs give rise to slower IPSCs in general, while faster IPSCs tend to be mediated by γ2 subunit-containing GABAARs.

  6. The contribution of delta subunit-containing GABAA receptors to phasic and tonic conductance changes in cerebellum, thalamus and neocortex.

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    Stephen G Brickley

    2013-12-01

    Full Text Available We have made use of the delta subunit-selective allosteric modulator DS2 (4-chloro-N-[2-(2-thienylimidazo[1,2-a]pyridine-3-yl benzamide to assay the contribution of delta-GABAARs to tonic and phasic conductance changes in the cerebellum, thalamus and neocortex. In cerebellar granule cells, an enhancement of the tonic conductance was observed for DS2 and the orthosteric agonist THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol. As expected, DS2 did not alter the properties of GABAA receptor-mediated inhibitory postsynaptic synaptic currents (IPSCs supporting a purely extrasynaptic role for delta-GABAARs in cerebellar granule cells. DS2 also enhanced the tonic conductance recorded from thalamic relay neurons of the visual thalamus with no alteration in IPSC properties. However, in addition to enhancing the tonic conductance DS2 also slowed the decay of IPSCs recorded from layer II/III neocortical neurons. A slowing of the IPSC decay also occurred in the presence of the voltage-gated sodium channel blocker TTX. Moreover, under conditions of reduced GABA release the ability of DS2 to enhance the tonic conductance was attenuated. These results indicate that delta-GABAARs can be activated following vesicular GABA release onto neocortical neurons and that the actions of DS2 on the tonic conductance may be influenced by the ambient GABA levels present in particular brain regions.

  7. Subthalamic deep brain stimulation reduces pathological information transmission to the thalamus in a rat model of parkinsonism

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    Collin James Anderson

    2015-07-01

    Full Text Available The degeneration of dopaminergic neurons in the substantia nigra pars compacta leads to parkinsonian motor symptoms via changes in electrophysiological activity throughout the basal ganglia. High-frequency deep brain stimulation (DBS partially treats these symptoms, but the mechanisms are unclear. We hypothesize that motor symptoms of Parkinson's disease are associated with increased information transmission from basal ganglia output neurons to motor thalamus input neurons, and that therapeutic DBS of the subthalamic nucleus (STN treats these symptoms by reducing this extraneous information transmission. We tested these hypotheses in a unilateral, 6-hydroxydopamine-lesioned rodent model of hemiparkinsonism. Information transfer between basal ganglia output neurons and motor thalamus input neurons increased in both the orthodromic and antidromic directions with hemiparkinsonian onset, and these changes were reversed by behaviorally therapeutic STN-DBS. Omnidirectional information increases in the parkinsonian state underscore the detrimental nature of that pathological information, and suggest a loss of information channel independence. Therapeutic STN-DBS reduced that pathological information, suggesting an effective increase in the number of independent information channels. We interpret these data with a model in which pathological information and fewer information channels diminishes the scope of possible motor activities, driving parkinsonian symptoms. In this model, STN-DBS restores information-channel independence by eliminating or masking the parkinsonism-associated information, and thus enlarges the scope of possible motor activities, alleviating parkinsonian symptoms.

  8. The thalamus and brainstem act as key hubs in alterations of human brain network connectivity induced by mild propofol sedation.

    Science.gov (United States)

    Gili, Tommaso; Saxena, Neeraj; Diukova, Ana; Murphy, Kevin; Hall, Judith E; Wise, Richard G

    2013-02-27

    Despite their routine use during surgical procedures, no consensus has yet been reached on the precise mechanisms by which hypnotic anesthetic agents produce their effects. Molecular, animal and human studies have suggested disruption of thalamocortical communication as a key component of anesthetic action at the brain systems level. Here, we used the anesthetic agent, propofol, to modulate consciousness and to evaluate differences in the interactions of remote neural networks during altered consciousness. We investigated the effects of propofol, at a dose that produced mild sedation without loss of consciousness, on spontaneous cerebral activity of 15 healthy volunteers using functional magnetic resonance imaging (fMRI), exploiting oscillations (eigenvector centrality (EC) to characterize brain network properties. The EC mapping of fMRI data in healthy humans under propofol mild sedation demonstrated a decrease of centrality of the thalamus versus an increase of centrality within the pons of the brainstem, highlighting the important role of these two structures in regulating consciousness. Specifically, the decrease of thalamus centrality results from its disconnection from a widespread set of cortical and subcortical regions, while the increase of brainstem centrality may be a consequence of its increased influence, in the mildly sedated state, over a few highly central cortical regions key to the default mode network such as the posterior and anterior cingulate cortices.

  9. The frontal lobe and thalamus have different sensitivities to hypoxia-hypotension after traumatic brain injury: a microdialysis study in rats.

    Science.gov (United States)

    Blanié, Antonia; Vigué, Bernard; Benhamou, Dan; Duranteau, Jacques; Geeraerts, Thomas

    2012-12-10

    After traumatic brain injury (TBI), lesions are anatomically heterogeneous, but the spatial heterogeneity of the post-traumatic brain's vulnerability to hypoxia-hypotension (HH) has been poorly studied. Our objective was to compare the effect of HH after TBI on brain energy metabolism into two regions: the frontal lobe and the thalamus. Twenty-eight Sprague-Dawley rats were randomized into four groups: sham, TBI (brain trauma alone, impact acceleration, 450-g weight drop from 1.8 m), HH (blood depletion to mean arterial pressure 40 mm Hg, FiO(2) 10%, 15 min), and TBI-HH (TBI followed by HH, 45-min delay). Cerebral perfusion pressure (CPP) was continuously measured. Brain microdialysis and brain tissue oxygen partial pressure (PtiO(2)) probes were both inserted stereotaxically into the right thalamus and frontal lobe. Except during the HH period, CPP was always above 60 mm Hg. During the hour following the HH period, significant increases in cerebral lactate-pyruvate ratio, glycerol, and glutamate were observed, and were always higher in the frontal lobe than in the thalamus (pfrontal lobe, increases in glutamate and glycerol were significantly higher than in the HH group (pfrontal lobe than in the thalamus. These findings demonstrate that in the early post-traumatic period, the metabolic cerebral response to HH is higher in the frontal lobe than in the thalamus, and is worsened by TBI, suggesting a higher vulnerability for the frontal lobes.

  10. Extrastriatal binding of [{sup 123}I]FP-CIT in the thalamus and pons: gender and age dependencies assessed in a European multicentre database of healthy controls

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Walter; Unterrainer, Marcus; Xiong, Guoming; Bartenstein, Peter [University of Munich, Department of Nuclear Medicine, Munich (Germany); Diemling, Markus [Hermes Medical Solutions, Stockholm (Sweden); Varrone, Andrea [Karolinska University Hospital, Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm (Sweden); Dickson, John C. [UCLH NHS Foundation Trust and University College, Institute of Nuclear Medicine, London (United Kingdom); Tossici-Bolt, Livia [University Hospitals Southampton NHS Trust, Department of Medical Physics, Southampton (United Kingdom); Sera, Terez [University of Szeged, Department of Nuclear Medicine and Euromedic Szeged, Szeged (Hungary); Asenbaum, Susanne [Medical University of Vienna, Department of Neurology, Vienna (Austria); Booij, Jan [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Centre, Amsterdam (Netherlands); Kapucu, Ozlem L. [Gazi University, Department of Nuclear Medicine, Faculty of Medicine, Ankara (Turkey); Kluge, Andreas [ABX-CRO, Dresden (Germany); Ziebell, Morten [Rigshospitalet and University of Copenhagen, Neurobiology Research Unit, Copenhagen (Denmark); Darcourt, Jacques [University of Nice-Sophia Antipolis, Nuclear Medicine Department, Centre Antoine Lacassagne, Nice (France); Nobili, Flavio [University of Genoa, Clinical Neurology Unit, Department of Neuroscience (DINOGMI), Genoa (Italy); Pagani, Marco [CNR, Institute of Cognitive Sciences and Technologies, Rome (Italy); Karolinska Hospital, Department of Nuclear Medicine, Stockholm (Sweden); Hesse, Swen [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Leipzig University Medical Centre, Molecular Neuroimaging IFB Adiposity Diseases, Leipzig (Germany); Borght, Thierry Vander [Universite Catholique de Louvain, Nuclear Medicine Division, CHU Dinant Godinne, Yvoir (Belgium); Laere, Koen van [University Hospital and K.U. Leuven, Nuclear Medicine, Leuven (Belgium); Tatsch, Klaus [Staedtisches Klinikum Karlsruhe, Department of Nuclear Medicine, Karlsruhe (Germany); La Fougere, Christian [University of Munich, Department of Nuclear Medicine, Munich (Germany); University of Tuebingen, Department of Nuclear Medicine, Tuebingen (Germany)

    2014-10-15

    Apart from binding to the dopamine transporter (DAT), [{sup 123}I]FP-CIT shows moderate affinity for the serotonin transporter (SERT), allowing imaging of both monoamine transporters in a single imaging session in different brain areas. The aim of this study was to systematically evaluate extrastriatal binding (predominantly due to SERT) and its age and gender dependencies in a large cohort of healthy controls. SPECT data from 103 healthy controls with well-defined criteria of normality acquired at 13 different imaging centres were analysed for extrastriatal binding using volumes of interest analysis for the thalamus and the pons. Data were examined for gender and age effects as well as for potential influence of striatal DAT radiotracer binding. Thalamic binding was significantly higher than pons binding. Partial correlations showed an influence of putaminal DAT binding on measured binding in the thalamus but not on the pons. Data showed high interindividual variation in extrastriatal binding. Significant gender effects with 31 % higher binding in women than in men were observed in the thalamus, but not in the pons. An age dependency with a decline per decade (±standard error) of 8.2 ± 1.3 % for the thalamus and 6.8 ± 2.9 % for the pons was shown. The potential to evaluate extrastriatal predominant SERT binding in addition to the striatal DAT in a single imaging session was shown using a large database of [{sup 123}I]FP-CIT scans in healthy controls. For both the thalamus and the pons, an age-related decline in radiotracer binding was observed. Gender effects were demonstrated for binding in the thalamus only. As a potential clinical application, the data could be used as a reference to estimate SERT occupancy in addition to nigrostriatal integrity when using [{sup 123}I]FP-CIT for DAT imaging in patients treated with selective serotonin reuptake inhibitors. (orig.)

  11. Thalamic reticular input to the rat visual thalamus: a single fiber study using biocytin as an anterograde tracer.

    Science.gov (United States)

    Pinault, D; Bourassa, J; Deschênes, M

    1995-01-23

    This study describes the axonal projections of single thalamic reticular (TR) neurons within the visual thalamus in rats. Experiments were performed under urethane anesthesia and reticular cells were labeled by extracellular or juxtacellular microiontophoretic applications of biocytin. The axonal arborizations of 19 TR cells projecting to the dorsal lateral geniculate nucleus (DLG) or to the lateral dorsal/lateral posterior complex (LD/LP) were reconstructed from serial horizontal sections. It was found that single TR cells projected within the limits of a single thalamic nucleus, either the DLG or the LD/LP complex, where their terminal fields formed rostrocaudally oriented rods (length: approximately 800 microns; diameter: approximately 100 microns) densely packed with grape-like boutons and varicosities. In addition, none of the labeled TR cells possessed recurrent axonal collaterals that ramified within the reticular complex itself. The functional implications of these morphological data for the synchronization of thalamic oscillations are discussed.

  12. Deep Brain Stimulation of Medial Dorsal and Ventral Anterior Nucleus of the Thalamus in OCD: A Retrospective Case Series.

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    Mohammad Maarouf

    Full Text Available The current notion that cortico-striato-thalamo-cortical circuits are involved in the pathophysiology of obsessive-compulsive disorder (OCD has instigated the search for the most suitable target for deep brain stimulation (DBS. However, despite extensive research, uncertainty about the ideal target remains with many structures being underexplored. The aim of this report is to address a new target for DBS, the medial dorsal (MD and the ventral anterior (VA nucleus of the thalamus, which has thus far received little attention in the treatment of OCD.In this retrospective trial, four patients (three female, one male aged 31-48 years, suffering from therapy-refractory OCD underwent high-frequency DBS of the MD and VA. In two patients (de novo group the thalamus was chosen as a primary target for DBS, whereas in two patients (rescue DBS group lead implantation was performed in a rescue DBS attempt following unsuccessful primary stimulation.Continuous thalamic stimulation yielded no significant improvement in OCD symptom severity. Over the course of thalamic DBS symptoms improved in only one patient who showed "partial response" on the Yale-Brown Obsessive Compulsive (Y-BOCS Scale. Beck Depression Inventory scores dropped by around 46% in the de novo group; anxiety symptoms improved by up to 34%. In the de novo DBS group no effect of DBS on anxiety and mood was observable.MD/VA-DBS yielded no adequate alleviation of therapy-refractory OCD, the overall strategy in targeting MD/VA as described in this paper can thus not be recommended in DBS for OCD. The magnocellular portion of MD (MDMC, however, might prove a promising target in the treatment of mood related and anxiety disorders.

  13. Deep Brain Stimulation of Medial Dorsal and Ventral Anterior Nucleus of the Thalamus in OCD: A Retrospective Case Series.

    Science.gov (United States)

    Maarouf, Mohammad; Neudorfer, Clemens; El Majdoub, Faycal; Lenartz, Doris; Kuhn, Jens; Sturm, Volker

    2016-01-01

    The current notion that cortico-striato-thalamo-cortical circuits are involved in the pathophysiology of obsessive-compulsive disorder (OCD) has instigated the search for the most suitable target for deep brain stimulation (DBS). However, despite extensive research, uncertainty about the ideal target remains with many structures being underexplored. The aim of this report is to address a new target for DBS, the medial dorsal (MD) and the ventral anterior (VA) nucleus of the thalamus, which has thus far received little attention in the treatment of OCD. In this retrospective trial, four patients (three female, one male) aged 31-48 years, suffering from therapy-refractory OCD underwent high-frequency DBS of the MD and VA. In two patients (de novo group) the thalamus was chosen as a primary target for DBS, whereas in two patients (rescue DBS group) lead implantation was performed in a rescue DBS attempt following unsuccessful primary stimulation. Continuous thalamic stimulation yielded no significant improvement in OCD symptom severity. Over the course of thalamic DBS symptoms improved in only one patient who showed "partial response" on the Yale-Brown Obsessive Compulsive (Y-BOCS) Scale. Beck Depression Inventory scores dropped by around 46% in the de novo group; anxiety symptoms improved by up to 34%. In the de novo DBS group no effect of DBS on anxiety and mood was observable. MD/VA-DBS yielded no adequate alleviation of therapy-refractory OCD, the overall strategy in targeting MD/VA as described in this paper can thus not be recommended in DBS for OCD. The magnocellular portion of MD (MDMC), however, might prove a promising target in the treatment of mood related and anxiety disorders.

  14. The effect of crack cocaine addiction on the microstructure and morphology of the human striatum and thalamus using novel shape analysis and fast diffusion kurtosis imaging

    DEFF Research Database (Denmark)

    Garza-Villarreal, Eduardo A.; Mallar, Chakravarty; Hansen, Brian

    2016-01-01

    The striatum and thalamus are subcortical structures intimately involved in addiction, and the morphology and microstructure of these has been studied in murine models of cocaine addiction. However, human studies using non-invasive MRI has shown inconsistencies in morphology using volumetric anal...

  15. Electrical stimulation of the substantia nigra reticulata : Detection of neuronal extracellular GABA in the ventromedial thalamus and its regulatory mechanism using microdialysis in awake rats

    NARCIS (Netherlands)

    Timmerman, W; Westerink, B.H.C.

    A combination of electrical stimulation and microdialysis was used to study the nigrothalamic gamma aminobutyric acid (GABA)ergic system and its regulatory mechanisms in awake rats. Extracellular GABA levels in the ventromedial nucleus of the thalamus were detected in S-min fractions collected

  16. Single cell firing patterns in the anterior nucleus of the thalamus relate to therapy response in deep brain stimulation for refractory epilepsy

    NARCIS (Netherlands)

    Schaper, F.; Zhao, Yan; Wagner, L.; Colon, A.; van Kranen-Mastenbroek, V.; Gommer, E.; Janssen, M.; Ackermans, L.; van Wezel, Richard Jack Anton; Temel, Y.; Heida, Tjitske; Rouhl, R.

    2016-01-01

    Introduction: Patients with medically refractory epilepsy treated with deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) vary highly in their therapy response. Proper positioning of the DBS lead is crucial to maximize efficacy and minimize side effects. For a correct

  17. Impaired functional connectivity of the thalamus in Alzheimer's disease and mild cognitive impairment: a resting-state fMRI study.

    Science.gov (United States)

    Zhou, Bo; Liu, Yong; Zhang, Zengqiang; An, Ningyu; Yao, Hongxiang; Wang, Pan; Wang, Luning; Zhang, Xi; Jiang, Tianzi

    2013-09-01

    The current study evaluated whether the functional connectivity pattern of the thalamo-cortical network in patients with Alzheimer' s disease (AD) and mild cognitive impairment (MCI) would show disease severityrelated alterations. Resting-state functional magnetic resonance imaging (MRI) data were obtained from 35 patients with AD, 27 patients with MCI and 27 subjects with normal cognition (NC). First, the altered functional connectivity pattern in AD patients was evaluated in comparison to NC subjects. Second, the MCI subjects were included to evaluate how different stages of disease affect the functional connectivity pattern of the thalamus. Finally, a correlation analysis was performed between the strength of the functional connectivity of the identified regions and various clinical variables to evaluate the relationship between the strength of functional connectivity and the cognitive abilities of MCI and AD patients. When compared to NC subjects, AD patients showed decreased functional connectivity between the left thalamus and brain regions including the precuneus/posterior cingulate cortex, right middle frontal gyrus and left inferior frontal gyrus. Decreased functional connectivity was also found between the right thalamus and right middle frontal gyrus and left inferior parietal lobule/angular gyrus. In addition, increased functional connectivity was observed between the bilateral thalamus and brain regions including the middle frontal gyrus, middle temporal gyrus, inferior temporal gyrus, superior parietal lobule, postcentral gyrus and precuneus. Functional connectivity between the bilateral thalamus and the identified brain regions of MCI subjects was intermediate in comparison to the functional connectivity of AD and NC subjects. A significant correlation between the fitted functional connectivity strength and the clinical variables was also detected. Our results revealed disease severity-related alterations of the thalamo-default mode network and

  18. Single axon branching analysis in rat thalamocortical projection from the anteroventral thalamus to the granular retrosplenial cortex

    Directory of Open Access Journals (Sweden)

    Saori eOdagiri

    2011-10-01

    Full Text Available The granular retrosplenial cortex (GRS in the rat has a distinct microcoluimn-type structure. The apical tufts of dendritic bundles at layer I, which are formed by layer II neurons, co-localize with patches of thalamic terminations from anteroventral thalamic nucleus (AV. To further understand this microcolumn-type structure in the GRS, one of remaining questions is whether this structure extends into other layers, such as layers III/IV. Other than layer I, previous tracer injection study showed that AV thalamic nucleus also projects to layer III/IV in the GRS. In this study, we examined the morphology of branches in the GRS from the AV thalamus in single axon branch resolution in order to determine whether AV axon branches in layer III/IV are branches of axons with extensive branch in layer I, and, if so, whether the extent of these arborizations in layer III/IV vertically matches with that in layer I. For this purpose, we used a small volume injection of biotinylated dextran-amine into the AV thalamus and reconstructing labeled single axon branches in the GRS. We found that the AV axons consisted of heterogeneous branching types. Type 1 had extensive arborization occurring only in layer Ia. Type 2 had additional branches in III/IV. Types 1 and 2 had extensive ramifications in layer Ia, with lateral extensions within the previously reported extensions of tufts from single dendritic bundles (i.e., 30-200 µm; mean 78 µm. In type 2 branches, axon arborizations in layer III/IV were just below to layer Ia ramifications, but much wider (148-533 µm: mean, 341 µm than that in layer Ia axon branches and dendritic bundles, suggesting that layer-specific information transmission spacing existed even from the same single axons from the AV to the GRS. Thus, microcolumn-type structure in the upper layer of the GRS was not strictly continuous from layer I to layer IV. How each layer and its components interact each other in different spatial scale should

  19. Identification of developmentally regulated PCP-responsive non-coding RNA, prt6, in the rat thalamus.

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    Hironao Takebayashi

    Full Text Available Schizophrenia and similar psychoses induced by NMDA-type glutamate receptor antagonists, such as phencyclidine (PCP and ketamine, usually develop after adolescence. Moreover, adult-type behavioral disturbance following NMDA receptor antagonist application in rodents is observed after a critical period at around 3 postnatal weeks. These observations suggest that the schizophrenic symptoms caused by and psychotomimetic effects of NMDA antagonists require the maturation of certain brain neuron circuits and molecular networks, which differentially respond to NMDA receptor antagonists across adolescence and the critical period. From this viewpoint, we have identified a novel developmentally regulated phencyclidine-responsive transcript from the rat thalamus, designated as prt6, as a candidate molecule involved in the above schizophrenia-related systems using a DNA microarray technique. The transcript is a non-coding RNA that includes sequences of at least two microRNAs, miR132 and miR212, and is expressed strongly in the brain and testis, with trace or non-detectable levels in the spleen, heart, liver, kidney, lung and skeletal muscle, as revealed by Northern blot analysis. The systemic administration of PCP (7.5 mg/kg, subcutaneously (s.c. significantly elevated the expression of prt6 mRNA in the thalamus at postnatal days (PD 32 and 50, but not at PD 8, 13, 20, or 24 as compared to saline-treated controls. At PD 50, another NMDA receptor antagonist, dizocilpine (0.5 mg/kg, s.c., and a schizophrenomimetic dopamine agonist, methamphetamine (4.8 mg/kg, s.c., mimicked a significant increase in the levels of thalamic prt6 mRNAs, while a D2 dopmamine receptor antagonist, haloperidol, partly inhibited the increasing influence of PCP on thalamic prt6 expression without its own effects. These data indicate that prt6 may be involved in the pathophysiology of the onset of drug-induced schizophrenia-like symptoms and schizophrenia through the possible

  20. Heritability of brain structure and glutamate levels in the anterior cingulate and left thalamus assessed with MR: A twin study

    DEFF Research Database (Denmark)

    Broberg, Brian Villumsen; Legind, Christian Stefan; Mandl, Rene C W

    included without their siblings. A 3D-T1W structural image and 1H nuclear magnetic resonance spectra (PRESS) was obtained from each subject using a 3 Tesla Philips MRI system. Total brain (TB), Gray matter (GM), white matter (WM), peripheral GM (pGM), ventricular CSF (vCSF) volumes were calculated using......Heritability of brain structure and glutamate levels in the anterior cingulate and left thalamus assessed with MR: A twin study Brian V. Broberg1,2; Christian S. Legind1,2, Rene C. Mandl1,3, Maria H. Jensen1, Simon J. Anhøj1,2, Rikke Hilker1, Egill Rostrup1,2, Birte Y. Glenthøj1 Author affiliations...... the heritability of regional cerebral glutamate levels as well as structural brain volumes. Methods Population: 18 monozygotic, 13 dizygotic twin pairs con- or discordant for schizophrenia (ICD-10, F. 20-29), 16 monozygotic healthy control pairs and 10 dizygotic healthy control pairs. Nine additional twins were...

  1. PKC-Dependent Signaling Pathways within PAG and Thalamus Contribute to the Nitric Oxide-Induced Nociceptive Behavior.

    Science.gov (United States)

    Galeotti, Nicoletta; Ghelardini, Carla

    2013-01-01

    Nitric oxide (NO) is an important molecule involved in nociceptive processing in the central nervous system. The release of NO within the spinal cord has long been implicated in the mechanisms underlying exaggerated pain sensitivity, and administration of NO donors can induce hyperalgesia. To elucidate the supraspinal mechanism responsible for NO-induced nociceptive hypersensitivity, we investigated the modulation of protein kinase C (PKC) and downstream effectors following treatment with the NO donors nitroglycerin and sodium nitroprusside. Both compounds induced a prolonged cold allodynia and heat hyperalgesia, increased levels of c-Fos and IL-1β, and activated NF-κB within periaqueductal grey matter and thalamus. Simultaneously, an increased expression and phosphorylation of PKC γ and ε were detected. To clarify the cellular mechanism involved in the NO-induced hypernociception, we examined the expression of transcription factors that act as PKC downstream effectors. A dramatic hyperphosphorylation of CREB and STAT1 was observed. The i.c.v. administration of the PKC blocker calphostin C prevented the NO-induced hypernociception, the hyperphosphorylation of CREB and STAT1, and partially reduced NF-κB activation. Conversely, the increase of IL-1β was unmodified by calphostin C. These results suggest the relevance of cerebral PKC-mediated CREB and STAT1 activation in the NO donor-induced nociceptive behavior.

  2. Whisking-Related Changes in Neuronal Firing and Membrane Potential Dynamics in the Somatosensory Thalamus of Awake Mice

    Directory of Open Access Journals (Sweden)

    Nadia Urbain

    2015-10-01

    Full Text Available The thalamus transmits sensory information to the neocortex and receives neocortical, subcortical, and neuromodulatory inputs. Despite its obvious importance, surprisingly little is known about thalamic function in awake animals. Here, using intracellular and extracellular recordings in awake head-restrained mice, we investigate membrane potential dynamics and action potential firing in the two major thalamic nuclei related to whisker sensation, the ventral posterior medial nucleus (VPM and the posterior medial group (Pom, which receive distinct inputs from brainstem and neocortex. We find heterogeneous state-dependent dynamics in both nuclei, with an overall increase in action potential firing during active states. Whisking increased putative lemniscal and corticothalamic excitatory inputs onto VPM and Pom neurons, respectively. A subpopulation of VPM cells fired spikes phase-locked to the whisking cycle during free whisking, and these cells may therefore signal whisker position. Our results suggest differential processing of whisking comparing thalamic nuclei at both sub- and supra-threshold levels.

  3. Effect of teriflunomide on cortex-basal ganglia-thalamus (CxBGTh circuit glutamatergic dysregulation in the Theiler's Murine Encephalomyelitis Virus mouse model of multiple sclerosis.

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    Claire M Modica

    Full Text Available Pathology of gray matter is associated with development of physical and cognitive disability in patients with multiple sclerosis. In particular, glutamatergic dysregulation in the cortex-basal ganglia-thalamus (CxBGTh circuit could be associated with decline in these behaviors.To investigate the effect of an immunomodulatory therapy (teriflunomide, Aubagio® on changes of the CxBGTh loop in the Theiler's Murine Encephalomyelitis Virus, (TMEV mouse model of MS.Forty-eight (48 mice were infected with TMEV, treated with teriflunomide (24 or control vehicle (24 and followed for 39 weeks. Mice were examined with MRS and volumetric MRI scans (0, 8, 26, and 39 weeks in the cortex, basal ganglia and thalamus, using a 9.4T scanner, and with behavioral tests (0, 4, 8, 12, 17, 26, and 39 weeks. Within conditions, MRI measures were compared between two time points by paired samples t-test and across multiple time points by repeated measures ANOVA (rmANOVA, and between conditions by independent samples t-test and rmANOVA, respectively. Data were considered as significant at the p<0.01 level and as a trend at p<0.05 level.In the thalamus, the teriflunomide arm exhibited trends toward decreased glutamate levels at 8 and 26 weeks compared to the control arm (p = 0.039 and p = 0.026, while the control arm exhibited a trend toward increased glutamate between 0 to 8 weeks (p = 0.045. In the basal ganglia, the teriflunomide arm exhibited a trend toward decreased glutamate earlier than the control arm, from 0 to 8 weeks (p = 0.011, resulting in decreased glutamate compared to the control arm at 8 weeks (p = 0.016.Teriflunomide may reduce possible excitotoxicity in the thalamus and basal ganglia by lowering glutamate levels.

  4. 3D texture analysis reveals imperceptible MRI textural alterations in the thalamus and putamen in progressive myoclonic epilepsy type 1, EPM1.

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    Sanna Suoranta

    Full Text Available Progressive myoclonic epilepsy type 1 (EPM1 is an autosomal recessively inherited neurodegenerative disorder characterized by young onset age, myoclonus and tonic-clonic epileptic seizures. At the time of diagnosis, the visual assessment of the brain MRI is usually normal, with no major changes found later. Therefore, we utilized texture analysis (TA to characterize and classify the underlying properties of the affected brain tissue by means of 3D texture features. Sixteen genetically verified patients with EPM1 and 16 healthy controls were included in the study. TA was performed upon 3D volumes of interest that were placed bilaterally in the thalamus, amygdala, hippocampus, caudate nucleus and putamen. Compared to the healthy controls, EPM1 patients had significant textural differences especially in the thalamus and right putamen. The most significantly differing texture features included parameters that measure the complexity and heterogeneity of the tissue, such as the co-occurrence matrix-based entropy and angular second moment, and also the run-length matrix-based parameters of gray-level non-uniformity, short run emphasis and long run emphasis. This study demonstrates the usability of 3D TA for extracting additional information from MR images. Textural alterations which suggest complex, coarse and heterogeneous appearance were found bilaterally in the thalamus, supporting the previous literature on thalamic pathology in EPM1. The observed putamenal involvement is a novel finding. Our results encourage further studies on the clinical applications, feasibility, reproducibility and reliability of 3D TA.

  5. Generation of a 3D atlas of the nuclear division of the thalamus based on histological sections of primate: Intra- and intersubject atlas-to-MRI warping

    Energy Technology Data Exchange (ETDEWEB)

    Dauguet, J.; Conde, F.; Hantraye, P.; Delzescaux, T. [CEA-CNRS, MIRCen, 18, route du Panorama, 92265 Fontenay-aux-Roses (France); Frouin, V. [CEA-DSV-IRCM-SCSR-LEFG, 2, place Gaston-Cremieux, 91057 Evry (France)

    2009-07-01

    We describe a framework to generate a 3D digital atlas of the thalamus based on a series of stained histological sections of a primate. The contours of the thalamus were first drawn on the stained histological slices. The series of histological sections were then aligned and mapped onto the in vivo MRI of the same animal acquired prior to the sacrifice following a methodology described in Dauguet et al. (2007) using the block face photographs as an intermediary modality. By applying the series of transformations previously estimated for the histological volume, the contours of the digital atlas were mapped onto the MRI data. The protocol was tested on two baboon brains for which the full series of slices were available, and a macaque brain for which a subset only of the histological slices were available demonstrating the ability of building digital atlases in the MRI geometry without mounting and staining all the brain slices. We then studied the accuracy of mapping the digital atlas of one baboon onto the MRI of the other baboon by comparing the overlapping with its original digital atlas. We finally used the digital atlas of one of the baboons to study the individual kinetic of the main thalamus nuclei on Positron Emission Tomography (PET) images providing a novel and accurate way of measuring very fine and local functional differences. (authors)

  6. Stimulation of the bilateral anterior nuclei of the thalamus in the treatment of refractory epilepsy: two cases of subcortical band heterotopia.

    Science.gov (United States)

    Franco, Ana; Pimentel, José; Campos, Alexandre Rainha; Morgado, Carlos; Pinelo, Sara; Ferreira, António Gonçalves; Bentes, Carla

    2016-12-01

    Subcortical band heterotopia is a neuronal migration disorder that may cause refractory epilepsy. In these patients, resective surgery has yielded inadequate results. Deep brain stimulation of the anterior nuclei of the thalamus has been used for the treatment of refractory epilepsy with good results. We describe the first two patients with subcortical band heterotopia who were submitted to deep brain stimulation of the anterior nuclei of the thalamus, with evaluation of seizure outcome after 12 and 18 months of follow-up. At these times, both showed a >50% decrease in seizure frequency and an increase in seizure freedom. Both patients had a depressive syndrome after surgery that responded fully to anti-depressive medication in one patient and partly in the other. In both, deep brain stimulation of the anterior nuclei of the thalamus was associated with good seizure outcome. This procedure can therefore be considered in the treatment of patients with subcortical band heterotopia and refractory epilepsy. Depression may be a transient adverse event of the surgery or stimulation, however, its aetiology is probably multifactorial.

  7. Cocaine- and amphetamine-regulated transcript (CART signaling within the paraventricular thalamus modulates cocaine-seeking behaviour.

    Directory of Open Access Journals (Sweden)

    Morgan H James

    Full Text Available BACKGROUND: Cocaine- and amphetamine-regulated transcript (CART has been demonstrated to play a role in regulating the rewarding and reinforcing effects of various drugs of abuse. A recent study demonstrated that i.c.v. administration of CART negatively modulates reinstatement of alcohol seeking, however, the site(s of action remains unclear. We investigated the paraventricular thalamus (PVT as a potential site of relapse-relevant CART signaling, as this region is known to receive dense innervation from CART-containing hypothalamic cells and to project to a number of regions known to be involved in mediating reinstatement, including the nucleus accumbens (NAC, medial prefrontal cortex (mPFC and basolateral amygdala (BLA. METHODOLOGY/PRINCIPAL FINDINGS: Male rats were trained to self-administer cocaine before being extinguished to a set criterion. One day following extinction, animals received intra-PVT infusions of saline, tetrodotoxin (TTX; 2.5 ng, CART (0.625 µg or 2.5 µg or no injection, followed by a cocaine prime (10 mg/kg, i.p.. Animals were then tested under extinction conditions for one hour. Treatment with either TTX or CART resulted in a significant attenuation of drug-seeking behaviour following cocaine-prime, with the 2.5 µg dose of CART having the greatest effect. This effect was specific to the PVT region, as misplaced injections of both TTX and CART resulted in responding that was identical to controls. CONCLUSIONS/SIGNIFICANCE: We show for the first time that CART signaling within the PVT acts to inhibit drug-primed reinstatement of cocaine seeking behaviour, presumably by negatively modulating PVT efferents that are important for drug seeking, including the NAC, mPFC and BLA. In this way, we identify a possible target for future pharmacological interventions designed to suppress drug seeking.

  8. Meditation reduces pain-related neural activity in the anterior cingulate cortex, insula, secondary somatosensory cortex, and thalamus.

    Directory of Open Access Journals (Sweden)

    Hiroki eNakata

    2014-12-01

    Full Text Available Recent studies have shown that meditation inhibits or relieves pain perception. To clarify the underlying mechanisms for this phenomenon, neuroimaging methods, such as functional magnetic resonance imaging (fMRI, and neurophysiological methods, such as magnetoencephalography (MEG and electroencephalography (EEG, have been used. However, it has been difficult to interpret the results, because there is some paradoxical evidence. For example, some studies reported increased neural responses to pain stimulation during meditation in the anterior cingulate cortex (ACC and insula, whereas others showed a decrease in these regions. There have been inconsistent findings to date. Moreover, in general, since the activities of the ACC and insula are correlated with pain perception, the increase in neural activities during meditation would be related to the enhancement of pain perception rather than its reduction. These contradictions might directly contribute to the ‘mystery of meditation’. In this review, we presented previous findings for brain regions during meditation and the anatomical changes that occurred in the brain with long-term meditation training. We then discussed the findings of previous studies that examined pain-related neural activity during meditation. We also described the brain mechanisms responsible for pain relief during meditation, and possible reasons for paradoxical evidence among previous studies. By thoroughly overviewing previous findings, we hypothesized that meditation reduces pain-related neural activity in the ACC, insula, secondary somatosensory cortex, and thalamus. We suggest that the characteristics of the modulation of this activity may depend on the kind of meditation and/or number of years of experience of meditation, which were associated with paradoxical findings among previous studies that investigated pain-related neural activities during meditation.

  9. Patient-Specific Electric Field Simulations and Acceleration Measurements for Objective Analysis of Intraoperative Stimulation Tests in the Thalamus.

    Science.gov (United States)

    Hemm, Simone; Pison, Daniela; Alonso, Fabiola; Shah, Ashesh; Coste, Jérôme; Lemaire, Jean-Jacques; Wårdell, Karin

    2016-01-01

    Despite an increasing use of deep brain stimulation (DBS) the fundamental mechanisms of action remain largely unknown. Simulation of electric entities has previously been proposed for chronic DBS combined with subjective symptom evaluations, but not for intraoperative stimulation tests. The present paper introduces a method for an objective exploitation of intraoperative stimulation test data to identify the optimal implant position of the chronic DBS lead by relating the electric field (EF) simulations to the patient-specific anatomy and the clinical effects quantified by accelerometry. To illustrate the feasibility of this approach, it was applied to five patients with essential tremor bilaterally implanted in the ventral intermediate nucleus (VIM). The VIM and its neighborhood structures were preoperatively outlined in 3D on white matter attenuated inversion recovery MR images. Quantitative intraoperative clinical assessments were performed using accelerometry. EF simulations (n = 272) for intraoperative stimulation test data performed along two trajectories per side were set-up using the finite element method for 143 stimulation test positions. The resulting EF isosurface of 0.2 V/mm was superimposed to the outlined anatomical structures. The percentage of volume of each structure's overlap was calculated and related to the corresponding clinical improvement. The proposed concept has been successfully applied to the five patients. For higher clinical improvements, not only the VIM but as well other neighboring structures were covered by the EF isosurfaces. The percentage of the volumes of the VIM, of the nucleus intermediate lateral of the thalamus and the prelemniscal radiations within the prerubral field of Forel increased for clinical improvements higher than 50% compared to improvements lower than 50%. The presented new concept allows a detailed and objective analysis of a high amount of intraoperative data to identify the optimal stimulation target. First

  10. Meditation reduces pain-related neural activity in the anterior cingulate cortex, insula, secondary somatosensory cortex, and thalamus

    Science.gov (United States)

    Nakata, Hiroki; Sakamoto, Kiwako; Kakigi, Ryusuke

    2014-01-01

    Recent studies have shown that meditation inhibits or relieves pain perception. To clarify the underlying mechanisms for this phenomenon, neuroimaging methods, such as functional magnetic resonance imaging, and neurophysiological methods, such as magnetoencephalography and electroencephalography, have been used. However, it has been difficult to interpret the results, because there is some paradoxical evidence. For example, some studies reported increased neural responses to pain stimulation during meditation in the anterior cingulate cortex (ACC) and insula, whereas others showed a decrease in these regions. There have been inconsistent findings to date. Moreover, in general, since the activities of the ACC and insula are correlated with pain perception, the increase in neural activities during meditation would be related to the enhancement of pain perception rather than its reduction. These contradictions might directly contribute to the ‘mystery of meditation.’ In this review, we presented previous findings for brain regions during meditation and the anatomical changes that occurred in the brain with long-term meditation training. We then discussed the findings of previous studies that examined pain-related neural activity during meditation. We also described the brain mechanisms responsible for pain relief during meditation, and possible reasons for paradoxical evidence among previous studies. By thoroughly overviewing previous findings, we hypothesized that meditation reduces pain-related neural activity in the ACC, insula, secondary somatosensory cortex, and thalamus. We suggest that the characteristics of the modulation of this activity may depend on the kind of meditation and/or number of years of experience of meditation, which were associated with paradoxical findings among previous studies that investigated pain-related neural activities during meditation. PMID:25566158

  11. Synaptic Contributions to Receptive Field Structure and Response Properties in the Rodent Lateral Geniculate Nucleus of the Thalamus.

    Science.gov (United States)

    Suresh, Vandana; Çiftçioğlu, Ulaş M; Wang, Xin; Lala, Brittany M; Ding, Kimberly R; Smith, William A; Sommer, Friedrich T; Hirsch, Judith A

    2016-10-26

    . In mouse retina, the most numerous cell type has the smallest receptive fields but lacks push-pull. The most common receptive field in rodent thalamus, however, is center-surround with push-pull. Thus, receptive field structure supersedes size per se for form vision. Further, for many orientation-selective cells, the second-order component of the receptive field aligned with stimulus preference, whereas suppression was untuned. Thus, inhibition may improve spatial resolution and sharpen other forms of selectivity in rodent lateral geniculate nucleus. Copyright © 2016 the authors 0270-6474/16/3610949-15$15.00/0.

  12. Effect of teriflunomide on cortex-basal ganglia-thalamus (CxBGTh) circuit glutamatergic dysregulation in the Theiler's Murine Encephalomyelitis Virus mouse model of multiple sclerosis.

    Science.gov (United States)

    Modica, Claire M; Schweser, Ferdinand; Sudyn, Michelle L; Bertolino, Nicola; Preda, Marilena; Polak, Paul; Siebert, Danielle M; Krawiecki, Jacqueline C; Sveinsson, Michele; Hagemeier, Jesper; Dwyer, Michael G; Pol, Suyog; Zivadinov, Robert

    2017-01-01

    Pathology of gray matter is associated with development of physical and cognitive disability in patients with multiple sclerosis. In particular, glutamatergic dysregulation in the cortex-basal ganglia-thalamus (CxBGTh) circuit could be associated with decline in these behaviors. To investigate the effect of an immunomodulatory therapy (teriflunomide, Aubagio®) on changes of the CxBGTh loop in the Theiler's Murine Encephalomyelitis Virus, (TMEV) mouse model of MS. Forty-eight (48) mice were infected with TMEV, treated with teriflunomide (24) or control vehicle (24) and followed for 39 weeks. Mice were examined with MRS and volumetric MRI scans (0, 8, 26, and 39 weeks) in the cortex, basal ganglia and thalamus, using a 9.4T scanner, and with behavioral tests (0, 4, 8, 12, 17, 26, and 39 weeks). Within conditions, MRI measures were compared between two time points by paired samples t-test and across multiple time points by repeated measures ANOVA (rmANOVA), and between conditions by independent samples t-test and rmANOVA, respectively. Data were considered as significant at the pteriflunomide arm exhibited trends toward decreased glutamate levels at 8 and 26 weeks compared to the control arm (p = 0.039 and p = 0.026), while the control arm exhibited a trend toward increased glutamate between 0 to 8 weeks (p = 0.045). In the basal ganglia, the teriflunomide arm exhibited a trend toward decreased glutamate earlier than the control arm, from 0 to 8 weeks (p = 0.011), resulting in decreased glutamate compared to the control arm at 8 weeks (p = 0.016). Teriflunomide may reduce possible excitotoxicity in the thalamus and basal ganglia by lowering glutamate levels.

  13. Nature against nurture: calcification in the right thalamus in a young man with anorexia nervosa and obsessive-compulsive personality disorder.

    Science.gov (United States)

    Conrad, Rupert; Wegener, Ingo; Geiser, Franziska; Imbierowicz, Katrin; Liedtke, Reinhard

    2008-10-01

    This report describes the case of a young man with a large calcification in the right thalamus that was first diagnosed at 9 years of age. Case history reveals specific eating rituals and other obsessive-compulsive personality traits during the patient's childhood and adolescence, fulfilling diagnostic criteria of obsessive-compulsive personality disorder. After a critical life event the patient develops anorexia nervosa. We suggest that our case and further literature provide evidence for an involvement of specific thalamic structures, such as the dorsomedial nucleus, in the development of anorexia nervosa. Furthermore, the treatment of the patient by a combined psychotherapeutic and pharmacotherapeutic approach is described. We focus on the beneficial effect of the atypical antipsychotic olanzapine, which can induce weight gain by an increase of leptin levels.

  14. Increased hippocampal, thalamus and amygdala volume in long-term lithium-treated bipolar I disorder patients compared with unmedicated patients and healthy subjects.

    Science.gov (United States)

    López-Jaramillo, Carlos; Vargas, Cristian; Díaz-Zuluaga, Ana M; Palacio, Juan David; Castrillón, Gabriel; Bearden, Carrie; Vieta, Eduard

    2017-02-01

    Magnetic resonance imaging (MRI) studies in bipolar I disorder (BD-I) suggest that lithium is associated with increased volumes of cortico-limbic structures. However, more rigorous control of confounding factors is needed to obtain further support for this hypothesis. The aim of the present study was to assess differences in brain volumes among long-term lithium-treated BD-I patients, unmedicated BD-I patients, and healthy controls. This was a cross-sectional study with 32 euthymic BD-I patients (16 on lithium monotherapy for a mean of 180 months, and 16 receiving no medication for at least the 2 months prior to the study) and 20 healthy controls. Patients were euthymic (Hamilton Depression Rating Scale [HDRS] lithium for at least 6 months. Brain images were acquired on a 1.5 Tesla MRI (Phillips, Amsterdam, The Netherlands) and segmented to generate volumetric measures of cortical and subcortical brain areas, ventricles and global brain. Significant differences were found in the volumes of the left amygdala (P=.0003), right amygdala (P=.030), left hippocampus (P=.022), left thalamus (P=.022), and right thalamus (P=.019) in long-term lithium-treated BD-I patients, compared to unmedicated patients and controls, after multivariable adjustment. No differences were observed in global brain volume or in ventricular size among the three groups. Likewise, there was no correlation between serum lithium levels and the increase in size in the described brain areas. The structural differences found among the three groups, and specifically those between long-term lithium-treated and unmedicated BD-I patients, indicate increased limbic structure volumes in lithium-treated patients. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Spontaneous locomotor activity correlates with the degranulation of mast cells in the meninges rather than in the thalamus: Disruptive effect of cocaine

    Science.gov (United States)

    Larson, Alice A.; Thomas, Mark J.; McElhose, Alex; Kovács, Katalin J.

    2011-01-01

    Mast cells are located in the central nervous system (CNS) of many mammals and stress induces their degranulation. We postulated that mast cells are associated with wakefulness and stimulatory tone in the CNS, as reflected by spontaneous motor activity. Because stress also precipitates drug-seeking behavior in cocaine addicts, we also postulated that cocaine manifests its effects through this relationship. We investigated the influence of single and repeated injections of cocaine on circulating corticosterone, motor activity and degranulation of mast cells in both the thalamus and meninges of mice. Mice were subjected to 5 consecutive days of cocaine or saline followed by a single injection of cocaine or saline 11 days later. Spontaneous locomotor activity was measure for one hour after the final injection before death. Neither a single injection nor prior treatment with cocaine increased motor activity compared to saline-injected controls, however, repeated administration of cocaine induced a significant sensitization to its behavioral effect when delivered 11 days later. In mice that received only saline, motor activity correlated positively with mast cell degranulation in the meninges but not in the thalamus. Cocaine, regardless of the treatment schedule, disrupted this correlation. The concentration of corticosterone did not differ amongst groups and did not correlate with either behavior or mast cell parameters in any group. The correlation between behavioral activity and the mast cell degranulation in the meninges suggests that these parameters are linked. The disruptive effect of cocaine on this relationship indicates a role downstream from mast cells in the regulation of motor activity. PMID:21561602

  16. Morphology of physiologically identified retinal X and Y axons in the cat's thalamus and midbrain as revealed by intraaxonal injection of biocytin.

    Science.gov (United States)

    Tamamaki, N; Uhlrich, D J; Sherman, S M

    1995-04-17

    Prior morphological studies of individual retinal X and Y axon arbors based on intraaxonal labeling with horseradish peroxidase have been limited by restricted diffusion or transport of the label. We used biocytin instead as the intraaxonal label, and this completely delineated each of our six X and 14 Y axons, including both thalamic and midbrain arbors. Arbors in the lateral geniculate nucleus appeared generally as has been well documented previously. Interestingly, all of the labeled axons projected a branch beyond thalamus to the midbrain. Each X axon formed a terminal arbor in the pretectum, but none continued to the superior colliculus. In contrast, 11 of 14 Y axons innervated both the pretectum and the superior colliculus, one innervated only the pretectum, and two innervated only the superior colliculus. Two of the Y axons were quite unusual in that their receptive fields were located well into the hemifield ipsilateral with respect to the hemisphere into which they were injected. These axons exhibited remarkable arbors in the lateral geniculate nucleus, diffusely innervating the C-laminae and medial interlaminar nucleus, but, unlike all other X and Y arbors, they did not innervate the A-laminae at all. In addition to these qualitative observations, we analyzed a number of quantitative features of these axons in terms of numbers and distributions of terminal boutons. We found that Y arbors contained more boutons than did X arbors in both thalamus and midbrain. Also, for axons with receptive fields in the contralateral hemifield (all X and all but two Y axons), 90-95% of their boutons terminated in the lateral geniculate nucleus; the other two Y axons had more of their arbors located in midbrain.

  17. Corticothalamic projections from the cortical barrel field to the somatosensory thalamus in rats: a single-fibre study using biocytin as an anterograde tracer.

    Science.gov (United States)

    Bourassa, J; Pinault, D; Deschênes, M

    1995-01-01

    This study investigated the pattern of axonal projections of single corticothalamic neurons from the cortical barrel field representing the vibrissae in the rat. Microiontophoretic injections of biocytin were performed in cortical layers V and VI to label small pools of corticothalamic cells and their intrathalamic axonal projections. After a survival period of 48 h, the animals were perfused and the tissue was processed for biocytin histochemistry. On the basis of the intrathalamic distribution of axonal fields and of the types of terminations found in the thalamus, four types of corticothalamic projections were identified. (i) Cells of the upper part of layer VI projected exclusively to the ventral posteromedial (VPm) nucleus, where they arborized in long rostrocaudally oriented bands or 'rods'. (ii) All cells of the lower part of layer VI projected to the medial part of the thalamic posterior group (Pom) but the vast majority of them also collateralized in VPm where they participated in the formation of rods. (iii) A minority of corticothalamic cells in the lower portion of layer VI, possibly located under the interbarrel spaces (septae), arborized exclusively in Pom. (iv) The corticothalamic projection of layer V cells originated from collaterals of corticofugal cells whose main axons ran caudally towards the brainstem. These collaterals arborized exclusively in Pom or in the central lateral nucleus. All corticothalamic cells from layer VI displayed the same type of axonal network, made of long branches decorated by terminal buttons emitted en passant at the tip of fine stalks. Corticothalamic fibres arising from layer V pyramids, however, remained smooth as they ran across the lateral thalamus and they generated in Pom one or two clusters of large boutons. All corticothalamic axons derived from layer VI cells, but not those derived from layer V cells, gave off collaterals as they traversed the thalamic reticular complex. These observations are discussed in the

  18. PET Mapping for Brain-Computer Interface Stimulation of the Ventroposterior Medial Nucleus of the Thalamus in Rats with Implanted Electrodes.

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    Zhu, Yunqi; Xu, Kedi; Xu, Caiyun; Zhang, Jiacheng; Ji, Jianfeng; Zheng, Xiaoxiang; Zhang, Hong; Tian, Mei

    2016-07-01

    Brain-computer interface (BCI) technology has great potential for improving the quality of life for neurologic patients. This study aimed to use PET mapping for BCI-based stimulation in a rat model with electrodes implanted in the ventroposterior medial (VPM) nucleus of the thalamus. PET imaging studies were conducted before and after stimulation of the right VPM. Stimulation induced significant orienting performance. (18)F-FDG uptake increased significantly in the paraventricular thalamic nucleus, septohippocampal nucleus, olfactory bulb, left crus II of the ansiform lobule of the cerebellum, and bilaterally in the lateral septum, amygdala, piriform cortex, endopiriform nucleus, and insular cortex, but it decreased in the right secondary visual cortex, right simple lobule of the cerebellum, and bilaterally in the somatosensory cortex. This study demonstrated that PET mapping after VPM stimulation can identify specific brain regions associated with orienting performance. PET molecular imaging may be an important approach for BCI-based research and its clinical applications. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  19. The Xenopus Irx genes are essential for neural patterning and define the border between prethalamus and thalamus through mutual antagonism with the anterior repressors Fezf and Arx.

    Science.gov (United States)

    Rodríguez-Seguel, Elisa; Alarcón, Pilar; Gómez-Skarmeta, José Luis

    2009-05-15

    The Iroquois (Irx) genes encode homeoproteins conserved during evolution. Vertebrate genomes contain six Irx genes organized in two clusters, IrxA (which harbors Irx1, Irx2 and Irx4) and IrxB (which harbors Irx3, Irx5 and Irx6). To determine the precise role of these genes during development and their putative redundancies, we conducted a comparative expression analysis and a comprehensive loss-of-function study of all the early expressed Irx genes (Irx1-5) using specific morpholinos in Xenopus. We found that the five Irx genes display largely overlapping expression patterns and contribute to neural patterning. All Irx genes are required for proper formation of posterior forebrain, midbrain, hindbrain and, to a lesser an extent, spinal cord. Nevertheless, Irx1 and Irx3 seem to have a predominant role during regionalization of the neural plate. In addition, we find that the common anterior limit of Irx gene expression, which will correspond to the future border between the prethalamus and thalamus, is defined by mutual repression between Fezf and Irx proteins. This mutual repression is likely direct. Finally, we show that Arx, another anteriorly expressed repressor, also contribute to delineate the anterior border of Irx expression.

  20. The effects of electrical stimulation or an electrolytic lesion in the mediodorsal thalamus of the rat on survival, body weight, food intake and running activity in the activity-based anorexia model

    OpenAIRE

    Luyten, Laura; Welkenhuysen, Marleen; Van Kuyck, Kris; Fieuws, Steffen; Das, John; Sciot, Raf; Nuttin, Bart

    2009-01-01

    The glucose metabolism in the mediodorsal thalamus (MD) is increased in rats in the activity-based anorexia (ABA) model. In patients, electrical stimulation in hyperactive brain regions reduced symptoms in e.g. major depressive disorder and cluster headache. In two blinded randomised controlled experiments, we therefore examined the effects of high-frequency electrical stimulation and an electrolytic lesion in the MD in a validated rat model for anorexia nervosa. The ABA model was successfull...

  1. Comparison of fMRI BOLD response patterns by electrical stimulation of the ventroposterior complex and medial thalamus of the rat.

    Directory of Open Access Journals (Sweden)

    Pai-Feng Yang

    Full Text Available The objective of this study was to compare the functional connectivity of the lateral and medial thalamocortical pain pathways by investigating the blood oxygen level-dependent (BOLD activation patterns in the forebrain elicited by direct electrical stimulation of the ventroposterior (VP and medial (MT thalamus. An MRI-compatible stimulation electrode was implanted in the VP or MT of α-chloralose-anesthetized rats. Electrical stimulation was applied to the VP or MT at various intensities (50 µA to 300 µA and frequencies (1 Hz to 12 Hz. BOLD responses were analyzed in the ipsilateral forelimb region of the primary somatosensory cortex (iS1FL after VP stimulation and in the ipsilateral cingulate cortex (iCC after MT stimulation. When stimulating the VP, the strongest activation occurred at 3 Hz. The stimulation intensity threshold was 50 µA and the response rapidly peaked at 100 µA. When stimulating the MT, The optimal frequency for stimulation was 9 Hz or 12 Hz, the stimulation intensity threshold was 100 µA and we observed a graded increase in the BOLD response following the application of higher intensity stimuli. We also evaluated c-Fos expression following the application of a 200-µA stimulus. Ventroposterior thalamic stimulation elicited c-Fos-positivity in few cells in the iS1FL and caudate putamen (iCPu. Medial thalamic stimulation, however, produced numerous c-Fos-positive cells in the iCC and iCPu. The differential BOLD responses and c-Fos expressions elicited by VP and MT stimulation indicate differences in stimulus-response properties of the medial and lateral thalamic pain pathways.

  2. Morphological, structural, and functional alterations of the prefrontal cortex and the basolateral amygdala after early lesion of the rat mediodorsal thalamus.

    Science.gov (United States)

    Ouhaz, Zakaria; Ba-M'hamed, Saadia; Bennis, Mohamed

    2017-08-01

    Early postnatal damage to the mediodorsal thalamus (MD) produces deficits in cognition and behavior believed to be associated with early prefrontal cortical maldevelopment. We assessed the role of MD afferents during development on the morphological and functional maturation of the prefrontal cortex (PFC) and the basolateral amygdala (BLA). Sprague-Dawley rat pups (n = 56) received a bilateral electrolytic lesion of the MD or a MD Sham lesion on postnatal day 4. 7 weeks later, all rats were tested in anxiety-related and cognitive paradigms using the elevated plus maze and novel object recognition tests. Following behavioral testing (P70), rats were killed and the baseline expression of C-Fos protein and the number of GABAergic neurons were evaluated in the PFC and the BLA. The dendritic morphology and spine density in the PFC using Golgi-Cox staining was also evaluated. Adult rats with early postnatal bilateral MD damage exhibited disrupted recognition memory and increased anxiety-like behaviors. The lesion also caused a significant diminution of C-Fos immunolabeling and an increase of the number of GABAergic neurons in the PFC. In the BLA, the number of GABAergic neurons was significantly reduced, associated with an increase in C-Fos immunolabeling. Furthermore, in the PFC the lesion induced a significant reduction in dendritic branching and spine density. Our data are consistent with the hypothesis that the MD plays a role in the development of the PFC and, therefore, may be a good animal model to investigate cognitive symptoms associated with schizophrenia.

  3. Tactile representation in somatosensory thalamus (VPL) and cortex (S1) of awake primate and the plasticity induced by VPL neuroprosthetic stimulation.

    Science.gov (United States)

    Song, Weiguo; Semework, Mulugeta

    2015-11-02

    To further understand how tactile information is carried in somatosensory cortex (S1) and the thalamus (VPL), and how neuronal plasticity after neuroprosthetic stimulation affects sensory encoding, we chronically implanted microelectrode arrays across hand areas in both S1 and VPL, where neuronal activities were simultaneously recorded during tactile stimulation on the finger pad of awake monkeys. Tactile information encoded in the firing rate of individual units (rate coding) or in the synchrony of unit pairs (synchrony coding) was quantitatively assessed within the information theoretic-framework. We found that tactile information encoded in VPL was higher than that encoded in S1 for both rate coding and synchrony coding; rate coding carried greater information than synchrony coding for the same recording area. With the aim for neuroprosthetic stimulation, plasticity of the circuit was tested after 30 min of VPL electrical stimulation, where stimuli were delivered either randomly or contingent on the spiking of an S1 unit. We showed that neural encoding in VPL was more stable than in S1, which depends not only on the thalamic input but also on recurrent feedback. The percent change of mutual-information after stimulation was increased with closed-loop stimulation, but decreased with random stimulation. The underlying mechanisms during closed-loop stimulation might be spike-timing-dependent plasticity, while frequency-dependent synaptic plasticity might play a role in random stimulation. Our results suggest that VPL could be a promising target region for somatosensory stimulation with closed-loop brain-machine-interface applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Role for the Ventral Posterior Medial/Posterior Lateral Thalamus and Anterior Cingulate Cortex in Affective/Motivation Pain Induced by Varicella Zoster Virus

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    Phillip R. Kramer

    2017-10-01

    Full Text Available Varicella zoster virus (VZV infects the face and can result in chronic, debilitating pain. The mechanism for this pain is unknown and current treatment is often not effective, thus investigations into the pain pathway become vital. Pain itself is multidimensional, consisting of sensory and affective experiences. One of the primary brain substrates for transmitting sensory signals in the face is the ventral posterior medial/posterior lateral thalamus (VPM/VPL. In addition, the anterior cingulate cortex (ACC has been shown to be vital in the affective experience of pain, so investigating both of these areas in freely behaving animals was completed to address the role of the brain in VZV-induced pain. Our lab has developed a place escape avoidance paradigm (PEAP to measure VZV-induced affective pain in the orofacial region of the rat. Using this assay as a measure of the affective pain experience a significant response was observed after VZV injection into the whisker pad and after VZV infusion into the trigeminal ganglion. Local field potentials (LFPs are the summed electrical current from a group of neurons. LFP in both the VPM/VPL and ACC was attenuated in VZV injected rats after inhibition of neuronal activity. This inhibition of VPM/VPL neurons was accomplished using a designer receptor exclusively activated by a designer drug (DREADD. Immunostaining showed that cells within the VPM/VPL expressed thalamic glutamatergic vesicle transporter-2, NeuN and DREADD suggesting inhibition occurred primarily in excitable neurons. From these results we conclude: (1 that VZV associated pain does not involve a mechanism exclusive to the peripheral nerve terminals, and (2 can be controlled, in part, by excitatory neurons within the VPM/VPL that potentially modulate the affective experience by altering activity in the ACC.

  5. Brain plasticity and microglia: is transsynaptic glial activation in the thalamus after limb denervation linked to cortical plasticity and central sensitisation?

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    Banati, Richard B

    2002-01-01

    Microglia are a subset of tissue-macrophages that are ubiquitously distributed throughout the entire CNS. In health, they remain largely dormant until activated by a pathological stimulus. The availability of more sensitive detection techniques has allowed the early measurement of the cell responses of microglia in areas with few signs of active pathology. Subtle neuronal injury can induce microglial activation in retrograde and anterograde projection areas remote from the primary lesion focus. There is also evidence that in cases of long-standing abnormal neuronal activity, such as in patients after limb amputation with chronic pain and phantom sensations, glial activation may occur transsynaptically in the thalamus. Such neuronally driven glial responses may be related to the emergence central sensitisation in chronic pain states or plasticity phenomena in the cerebral cortex. It is suggested, that such persistent low-level microglial activation is not adequately described by the traditional concept of phagocyte-mediated tissue damage that largely evolved from studies of acute brain lesion models or acute human brain pathology. Due to the presence of signal molecules that can act on neurons and microglia alike, the communication between neurons and microglia is likely to be bi-directional. Persistent subtle microglial activity may modulate basal synaptic transmission and thus neuronal functioning either directly or through the interaction with astrocytes. The activation of microglia leads to the emergence of microstructural as well as functional compartments in which neurokines, interleukins and other signalling molecules introduce a qualitatively different, more open mode of cell-cell communication that is normally absent from the healthy adult brain. This 'neo-compartmentalisation', however, occurs along predictable neuronal pathways within which these glial changes are themselves under the modulatory influence of neurons or other glial cells and are subject to

  6. Defining the anterior nucleus of the thalamus (ANT) as a deep brain stimulation target in refractory epilepsy: Delineation using 3 T MRI and intraoperative microelectrode recording.

    Science.gov (United States)

    Möttönen, T; Katisko, J; Haapasalo, J; Tähtinen, T; Kiekara, T; Kähärä, V; Peltola, J; Öhman, J; Lehtimäki, K

    2015-01-01

    Deep brain stimulation (DBS) is a minimally invasive and reversible method to treat an increasing number of neurological and psychiatric disorders, including epilepsy. Targeting poorly defined deep structures is based in large degree on stereotactic atlas information, which may be a major source of inconsistent treatment effects. In the present study, we aimed to study whether a recently approved target for epilepsy (anterior nucleus of thalamus, ANT) is visualized in clinically established 3 T MRI and whether ANT is delineated using intraoperative microelectrode recording (MER). We have especially focused on individual variation in the location of ANT in stereotactic space. We also aimed to demonstrate the role of individual variation in interpretation of MER data by projecting samples onto AC-PC (anterior and posterior commissure) and ANT-normalized coordinate systems. Detailed analysis of ANT delineations in 3 T MRI short tau inversion recovery (STIR) images from eight patients undergoing DBS for refractory epilepsy was performed. Coronal and sagittal cross-sectional models of ANT were plotted in the AC-PC coordinate system to study individual variation. A total of 186 MER samples collected from 10 DBS trajectories and 5 patients were analyzed, and the location of each sample was calculated and corrected accordingly to the location of the final DBS electrode and projected to the AC-PC or coordinate system normalized to ANT. Most of the key structures in the anatomic atlas around ANT (mammillothalamic tract and external medullary lamina) were identified in STIR images allowing visual delineation of ANT. We observed a high degree of anatomical variation in the location of ANT, and the cross-sectional areas overlapped by study patients decreased in a linear fashion with an increasing number of patients. MER information from 10 individual trajectories correlated with STIR signal characteristics by demonstrating a spike-negative zone, presumably white matter layer

  7. A pathway for predation in the brain of the barn owl (Tyto alba): projections of the gracile nucleus to the "claw area" of the rostral wulst via the dorsal thalamus.

    Science.gov (United States)

    Wild, J M; Kubke, M F; Peña, J L

    2008-07-10

    The Wulst of birds, which is generally considered homologous with the isocortex of mammals, is an elevation on the dorsum of the telencephalon that is particularly prominent in predatory species, especially those with large, frontally placed eyes, such as owls. The Wulst, therefore, is largely visual, but a relatively small rostral portion is somatosensory in nature. In barn owls, this rostral somatosensory part of the Wulst forms a unique physical protuberance dedicated to the representation of the contralateral claw. Here we investigate whether the input to this "claw area" arises from dorsal thalamic neurons that, in turn, receive their somatosensory input from the gracile nucleus. After injections of biotinylated dextran amine into the gracile nucleus and cholera toxin B chain into the claw area, terminations from the former and retrogradely labeled neurons from the latter overlapped substantially in the thalamic nucleus dorsalis intermedius ventralis anterior. These results indicate the existence in this species of a "classical" trisynaptic somatosensory pathway from the body periphery to the telencephalic Wulst, via the dorsal thalamus, one that is likely involved in the barn owl's predatory behavior. The results are discussed in the context of somatosensory projections, primarily in this and other avian species. (c) 2008 Wiley-Liss, Inc.

  8. The effects of electrical stimulation or an electrolytic lesion in the mediodorsal thalamus of the rat on survival, body weight, food intake and running activity in the activity-based anorexia model.

    Science.gov (United States)

    Luyten, Laura; Welkenhuysen, Marleen; van Kuyck, Kris; Fieuws, Steffen; Das, John; Sciot, Raf; Nuttin, Bart

    2009-04-29

    The glucose metabolism in the mediodorsal thalamus (MD) is increased in rats in the activity-based anorexia (ABA) model. In patients, electrical stimulation in hyperactive brain regions reduced symptoms in e.g. major depressive disorder and cluster headache. In two blinded randomised controlled experiments, we therefore examined the effects of high-frequency electrical stimulation and an electrolytic lesion in the MD in a validated rat model for anorexia nervosa. The ABA model was successfully replicated in all our experiments, with a reduction in body weight, food intake, and survival time and an increase in running activity. In a first experiment, we evaluated the effect of electrical stimulation or a curative lesion in the MD on survival, body weight, food intake and locomotor activity in ABA rats. Electrical MD stimulation or an electrolytic MD lesion did not improve the symptoms of rats in the ABA model, compared to control groups. In a second experiment, we investigated the effect of a preventive electrolytic lesion in the MD on rats in the ABA model. Although there was no significant improvement of survival, body weight and food intake, locomotor activity was significantly reduced in the lesion group compared to the control group. Apart from this positive effect on running activity, we found no convincing evidence for the suitability of the MD as a neuromodulation target for anorexia nervosa patients.

  9. The paraventricular nucleus of the thalamus is recruited by both natural rewards and drugs of abuse: recent evidence of a pivotal role for orexin/hypocretin signaling in this thalamic nucleus in drug-seeking behavior

    Directory of Open Access Journals (Sweden)

    Alessandra eMatzeu

    2014-04-01

    Full Text Available A major challenge for the successful treatment of drug addiction is the long-lasting susceptibility to relapse and multiple processes that have been implicated in the compulsion to resume drug intake during abstinence. Recently, the orexin/hypocretin (Orx/Hcrt system has been shown to play a role in drug-seeking behavior. The Orx/Hcrt system regulates a wide range of physiological processes, including feeding, energy metabolism, and arousal. It has also been shown to be recruited by drugs of abuse. Orx/Hcrt neurons are predominantly located in the lateral hypothalamus that projects to the paraventricular nucleus of the thalamus (PVT, a region that has been identified as a way-station that processes information and then modulates the mesolimbic reward and extrahypothalamic stress systems. Although not thought to be part of the drug addiction circuitry, recent evidence indicates that the PVT is involved in the modulation of reward function in general and drug-directed behavior in particular. Evidence indicates a role for Orx/Hcrt transmission in the PVT in the modulation of reward function in general and drug-directed behavior in particular. One hypothesis is that following repeated drug exposure, the Orx/Hcrt system acquires a preferential role in mediating the effects of drugs vs. natural rewards. The present review discusses recent findings that suggest maladaptive recruitment of the PVT by drugs of abuse, specifically Orx/Hcrt-PVT neurotransmission.

  10. A pilot study of basal ganglia and thalamus structure by high dimensional mapping in children with Tourette syndrome [v1; ref status: indexed, http://f1000r.es/1yu

    Directory of Open Access Journals (Sweden)

    Alton C. Williams

    2013-10-01

    Full Text Available Background: Prior brain imaging and autopsy studies have suggested that structural abnormalities of the basal ganglia (BG nuclei may be present in Tourette Syndrome (TS. These studies have focused mainly on the volume differences of the BG structures and not their anatomical shapes.  Shape differences of various brain structures have been demonstrated in other neuropsychiatric disorders using large-deformation, high dimensional brain mapping (HDBM-LD.  A previous study of a small sample of adult TS patients demonstrated the validity of the method, but did not find significant differences compared to controls. Since TS usually begins in childhood and adult studies may show structure differences due to adaptations, we hypothesized that differences in BG and thalamus structure geometry and volume due to etiological changes in TS might be better characterized in children. Objective: Pilot the HDBM-LD method in children and estimate effect sizes. Methods: In this pilot study, T1-weighted MRIs were collected in 13 children with TS and 16 healthy, tic-free, control children. The groups were well matched for age.  The primary outcome measures were the first 10 eigenvectors which are derived using HDBM-LD methods and represent the majority of the geometric shape of each structure, and the volumes of each structure adjusted for whole brain volume. We also compared hemispheric right/left asymmetry and estimated effect sizes for both volume and shape differences between groups. Results: We found no statistically significant differences between the TS subjects and controls in volume, shape, or right/left asymmetry.  Effect sizes were greater for shape analysis than for volume. Conclusion: This study represents one of the first efforts to study the shape as opposed to the volume of the BG in TS, but power was limited by sample size. Shape analysis by the HDBM-LD method may prove more sensitive to group differences.

  11. Paraventricular thalamus: Gateway to feeding, appetitive motivation, and drug addiction.

    Science.gov (United States)

    Millan, E Zayra; Ong, ZhiYi; McNally, Gavan P

    2017-01-01

    This chapter reviews the anatomical and functional evidence demonstrating the contribution of the paraventricular thalamic nucleus (PVT) to appetitive motivation, food intake control, and drug-seeking behaviors. We first consider the anatomical properties of the PVT to highlight its relevance in the control of appetitive motivation, feeding, and drug seeking. This is followed by a review of the available literature on PVT neurocircuitry, PVT involvement in food intake control, animal models of drug self-administration, withdrawal, and relapse. We show that PVT occupies a strategic position as a major thalamic interface between hindbrain and hypothalamic regions for viscerosensation and energy states; and between amygdala, cortical, and ventral striatal regions for motivation, reward, and learning. Understanding the precise anatomical and functional organization of these trans-PVT pathways remains a key challenge. Nonetheless, we show that PVT may be profitably viewed as the thalamic gateway to appetitive motivation, feeding, and drug addiction allowing both bottom-up (from brainstem and hypothalamus) and top-down (from cortex) control over reward and motivation. © 2017 Elsevier B.V. All rights reserved.

  12. Spatially distributed encoding of covert attentional shifts in human thalamus

    DEFF Research Database (Denmark)

    Hulme, Oliver J; Whiteley, Louise Emma; Shipp, Stewart

    2010-01-01

    . Target position was cued after stimulus offset, requiring subjects to perform target detection from iconic visual memory. We found positionally specific responses at multiple thalamic sites, with individual voxels activating at more than one direction of attentional shift. Voxel clusters at anatomically...... the thalamic territory of cortical "eye-field" areas, thus supporting theories which propose the visuomotor origins of covert attentional selection....

  13. Structural parcellation of the thalamus using shortest-path tractography

    DEFF Research Database (Denmark)

    Kasenburg, Niklas; Darkner, Sune; Hahn, Ute

    2016-01-01

    to each cortical target region. Calculation of these statistical measures is derived from a rank-based test on the histogram of tract-based scores from all the shortest paths found between the source voxel and each voxel within the target region. Using data from the Human Connectome Project, we show...

  14. Stimulus size dependence of information transfer from retina to thalamus

    Directory of Open Access Journals (Sweden)

    Robert Uglesich

    2009-10-01

    Full Text Available Relay cells in the mammalian lateral geniculate nucleus (LGN are driven primarily by single retinal ganglion cells (RGCs. However, an LGN cell responds typically to less than half of the spikes it receives from the RGC that drives it, and without retinal drive the LGN is silent (Kaplan and Shapley, 1984. Recent studies, which used stimuli restricted to the receptive field (RF center, show that despite the great loss of spikes, more than half of the information carried by the RGC discharge is typically preserved in the LGN discharge (Sincich et al., 2009, suggesting that the retinal spikes that are deleted by the LGN carry less information than those that are transmitted to the cortex. To determine how LGN relay neurons decide which retinal spikes to respond to, we recorded extracellularly from the cat LGN the LGN spikes together with the slow synaptic (‘S’ potentials that signal the firing of retinal spikes. We investigated the influence of the inhibitory surround of the LGN RF by stimulating the eyes with spots of various sizes, the largest of which covered the center and surround of the LGN relay cell’s RF. We found that for stimuli that activated mostly the RF center, each LGN spike delivered more information than the retinal spike, but this difference was reduced as stimulus size increased to cover the RF surround. To evaluate the optimality of the LGN editing of retinal spikes, we created artificial spike trains from the retinal ones by various deletion schemes. We found that single LGN cells transmitted less information than an optimal detector could.

  15. Dopamine controls Parkinson's tremor by inhibiting the cerebellar thalamus

    NARCIS (Netherlands)

    Dirkx, M.F.M.; Ouden, H.E.M. den; Aarts, E.; Timmer, M.H.M.; Bloem, B.R.; Toni, I.; Helmich, R.C.G.

    2017-01-01

    Parkinson's resting tremor is related to altered cerebral activity in the basal ganglia and the cerebello-thalamo-cortical circuit. Although Parkinson's disease is characterized by dopamine depletion in the basal ganglia, the dopaminergic basis of resting tremor remains unclear: dopaminergic

  16. Brain state dependent activity in the cortex and thalamus.

    Science.gov (United States)

    McCormick, David A; McGinley, Matthew J; Salkoff, David B

    2015-04-01

    Cortical and thalamocortical activity is highly state dependent, varying between patterns that are conducive to accurate sensory-motor processing, to states in which the brain is largely off-line and generating internal rhythms irrespective of the outside world. The generation of rhythmic activity occurs through the interaction of stereotyped patterns of connectivity together with intrinsic membrane and synaptic properties. One common theme in the generation of rhythms is the interaction of a positive feedback loop (e.g., recurrent excitation) with negative feedback control (e.g., inhibition, adaptation, or synaptic depression). The operation of these state-dependent activities has wide ranging effects from enhancing or blocking sensory-motor processing to the generation of pathological rhythms associated with psychiatric or neurological disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Immediate and long-term plasticity in human somatosensory thalamus and its involvement in phantom limbs.

    Science.gov (United States)

    Dostrovsky, J O

    1999-08-01

    This paper describes studies on plasticity that the author undertook with Patrick Wall in the mid '70s, and then reviews recent related studies in humans carried out in the author's laboratory. The human studies have shown that thalamic neurons frequently have subliminal receptive fields (RFs) and immediately following a reversible block of afferent activity from the RF some neurons develop increased sensitivity to tactile stimulation at sites outside their normal RF. Also described and discussed are novel findings in patients that had a limb amputated. The results suggested an expansion of the representation of the proximal limb into the thalamic region that used to represent the amputated part. Furthermore, in those patients that had a phantom limb, microstimulation in this region induced sensations perceived as originating on the phantom.

  18. INFLUENCE OF THE ANTEROMEDIAL THALAMUS ON SOCIAL DEFEAT-ASSOCIATED CONTEXTUAL FEAR MEMORY.

    Science.gov (United States)

    Rangel, Miguel J; Baldo, Marcus Vinicius C; Canteras, Newton Sabino

    2017-11-02

    The ventral part of the anteromedial thalamic nucleus (AMv) is heavily targeted by the dorsal premammillary nucleus (PMd), which is the main hypothalamic site that is responsive to both predator and conspecific aggressor threats. This PMd-AMv pathway is likely involved in modulating memory processing, and previous findings from our group have shown that cytotoxic lesions or pharmacological inactivation of the AMv drastically reduced contextual fear responses to predator-associated environments. In the present study, we investigated the role of the AMv in both unconditioned (i.e., fear responses during social defeat) and contextual fear responses (i.e., during exposure to a social defeat-associated context). We addressed this question by placing N-methyl-D-aspartate (NMDA) lesions in the AMv and testing unconditioned fear responses during social defeat and contextual fear responses during exposure to a social defeat-associated context. Accordingly, bilateral AMv lesions did not change unconditioned responses, but decreased contextual conditioning related to social defeat. Notably, our bilateral AMv lesions also included, to a certain degree, the nucleus reuniens (RE), but single RE lesions did not affect innate or contextual fear responses. Overall, our results support the idea that the AMv works as a critical hub, receiving massive inputs from a hypothalamic site that is largely responsive to social threats and transferring social threat information to circuits involved in the processing of contextual fear memories. Copyright © 2017. Published by Elsevier B.V.

  19. The Anterior Thalamus Provides A Subcortical Circuit Supporting Memory And Spatial Navigation

    Directory of Open Access Journals (Sweden)

    Shane M O‘Mara

    2013-08-01

    Full Text Available The anterior thalamic nuclei, a central component of Papez’ circuit, are generally assumed to be key constituents of the neural circuits responsible for certain categories of learning and memory. Supporting evidence for this contention is that damage to either of two brain regions, the medial temporal lobe and the medial diencephalon, is most consistently associated with anterograde amnesia. Within these respective regions, the hippocampal formation and the anterior thalamic nuclei (anteromedial, anteroventral, anterodorsal are the particular structures of interest. The extensive direct and indirect hippocampal-anterior thalamic interconnections and the presence of theta-modulated cells in both sites further support the hypothesis that these structures constitute a neuronal network crucial for memory and cognition. The major tool in understanding how the brain processes information is the analysis of neuronal output at each hierarchical level along the pathway of signal propagation coupled with neuroanatomical studies. Here, we discuss the electrophysiological properties of cells in the anterior thalamic nuclei with an emphasis on their role in spatial navigation. In addition, we describe neuroanatomical and functional relationships between the anterior thalamic nuclei and hippocampal formation.

  20. Muscarinic receptor binding increases in anterior thalamus and cingulate cortex during discriminative avoidance learning

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, B.A.; Gabriel, M.; Vogt, L.J.; Poremba, A.; Jensen, E.L.; Kubota, Y.; Kang, E. (Department of Physiology and Pharmacology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina (USA))

    1991-06-01

    Training-induced neuronal activity develops in the mammalian limbic system during discriminative avoidance conditioning. This study explores behaviorally relevant changes in muscarinic ACh receptor binding in 52 rabbits that were trained to one of five stages of conditioned response acquisition. Sixteen naive and 10 animals yoked to criterion performance served as control cases. Upon reaching a particular stage of training, the brains were removed and autoradiographically assayed for 3H-oxotremorine-M binding with 50 nM pirenzepine (OxO-M/PZ) or for 3H-pirenzepine binding in nine limbic thalamic nuclei and cingulate cortex. Specific OxO-M/PZ binding increased in the parvocellular division of the anterodorsal nucleus early in training when the animals were first exposed to pairing of the conditional and unconditional stimuli. Elevated binding in this nucleus was maintained throughout subsequent training. In the parvocellular division of the anteroventral nucleus (AVp), OxO-M/PZ binding progressively increased throughout training, reached a peak at the criterion stage of performance, and returned to control values during extinction sessions. Peak OxO-M/PZ binding in AVp was significantly elevated over that for cases yoked to criterion performance. In the magnocellular division of the anteroventral nucleus (AVm), OxO-M/PZ binding was elevated only during criterion performance of the task, and it was unaltered in any other limbic thalamic nuclei. Specific OxO-M/PZ binding was also elevated in most layers in rostral area 29c when subjects first performed a significant behavioral discrimination. Training-induced alterations in OxO-M/PZ binding in AVp and layer Ia of area 29c were similar and highly correlated.

  1. The Differential Effects of Thalamus and Basal Ganglia on Facial Emotion Recognition

    Science.gov (United States)

    Cheung, Crystal C. Y.; Lee, Tatia M. C.; Yip, James T. H.; King, Kristin E.; Li, Leonard S. W.

    2006-01-01

    This study examined if subcortical stroke was associated with impaired facial emotion recognition. Furthermore, the lateralization of the impairment and the differential profiles of facial emotion recognition deficits with localized thalamic or basal ganglia damage were also studied. Thirty-eight patients with subcortical strokes and 19 matched…

  2. Multilaminar networks of cortical neurons integrate common inputs from sensory thalamus.

    Science.gov (United States)

    Morgenstern, Nicolás A; Bourg, Jacques; Petreanu, Leopoldo

    2016-08-01

    Neurons in the thalamorecipient layers of sensory cortices integrate thalamic and recurrent cortical input. Cortical neurons form fine-scale, functionally cotuned networks, but whether interconnected cortical neurons within a column process common thalamocortical inputs is unknown. We tested how local and thalamocortical connectivity relate to each other by analyzing cofluctuations of evoked responses in cortical neurons after photostimulation of thalamocortical axons. We found that connected pairs of pyramidal neurons in layer (L) 4 of mouse visual cortex share more inputs from the dorsal lateral geniculate nucleus than nonconnected pairs. Vertically aligned connected pairs of L4 and L2/3 neurons were also preferentially contacted by the same thalamocortical axons. Our results provide a circuit mechanism for the observed amplification of sensory responses by L4 circuits. They also show that sensory information is concurrently processed in L4 and L2/3 by columnar networks of interconnected neurons contacted by the same thalamocortical axons.

  3. Microsurgical management of deep ruptured arteriovenous malformations of the basal ganglia and thalamus

    Directory of Open Access Journals (Sweden)

    Sandu Aurelia Mihaela

    2014-03-01

    Full Text Available Introduction : Deep AVMs are more difficult to operate compared with other supratentorial locations due to the long working corridor through the brain, location in eloquent areas and vicinity with brain critical structures.

  4. Genetics Home Reference: leukoencephalopathy with thalamus and brainstem involvement and high lactate

    Science.gov (United States)

    ... Additional Information & Resources MedlinePlus (2 links) Encyclopedia: Head MRI Health Topic: Leukodystrophies Additional NIH Resources (1 link) National Institute of Neurological Disorders and Stroke: Leukodystrophy Information Page Educational Resources ( ...

  5. Recall deficits in stroke patients with thalamic lesions covary with damage to the parvocellular mediodorsal nucleus of the thalamus.

    Science.gov (United States)

    Pergola, Giulio; Güntürkün, Onur; Koch, Benno; Schwarz, Michael; Daum, Irene; Suchan, Boris

    2012-08-01

    The functional role of the mediodorsal thalamic nucleus (MD) and its cortical network in memory processes is discussed controversially. While Aggleton and Brown (1999) suggested a role for recognition and not recall, Van der Werf et al. (2003) suggested that this nucleus is functionally related to executive function and strategic retrieval, based on its connections to the prefrontal cortices (PFC). The present study used a lesion approach including patients with focal thalamic lesions to examine the functions of the MD, the intralaminar nuclei and the midline nuclei in memory processing. A newly designed pair association task was used, which allowed the assessment of recognition and cued recall performance. Volume loss in thalamic nuclei was estimated as a predictor for alterations in memory performance. Patients performed poorer than healthy controls on recognition accuracy and cued recall. Furthermore, patients responded slower than controls specifically on recognition trials followed by successful cued recall of the paired associate. Reduced recall of picture pairs and increased response times during recognition followed by cued recall covaried with the volume loss in the parvocellular MD. This pattern suggests a role of this thalamic region in recall and thus recollection, which does not fit the framework proposed by Aggleton and Brown (1999). The functional specialization of the parvocellular MD accords with its connectivity to the dorsolateral PFC, highlighting the role of this thalamocortical network in explicit memory (Van der Werf et al., 2003). Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. [Functional significance of the round nuclei of the thalamus in formation of the sleep--wakefulness cycle].

    Science.gov (United States)

    Karmanova, I G; Khomutetskaia, O E; Obshchina, N V

    1977-07-01

    In chicken with bilaterally lesioned thalamic rotundus nuclei, cholinomimetic effect of arecolin upon duration of each stage of the wakefulness--sleep cycle, was studied. No prolongation of the paradoxical sleep characteristic of the animals with intact thalamic nuclei, was observed in experimental chicken. The latter developed mainly a king of cataleptic immobilization duration of which was enhanced by arecolin administration. The thalamic rotundus nucleus was concluded to play an essential role in the mechanisms for regulation of the wakefulness--sleep cycle in birds.

  7. PKC-Dependent Signaling Pathways within PAG and Thalamus Contribute to the Nitric Oxide-Induced Nociceptive Behavior

    OpenAIRE

    Galeotti, Nicoletta; Ghelardini, Carla

    2013-01-01

    Nitric oxide (NO) is an important molecule involved in nociceptive processing in the central nervous system. The release of NO within the spinal cord has long been implicated in the mechanisms underlying exaggerated pain sensitivity, and administration of NO donors can induce hyperalgesia. To elucidate the supraspinal mechanism responsible for NO-induced nociceptive hypersensitivity, we investigated the modulation of protein kinase C (PKC) and downstream effectors following treatment with the...

  8. Medio-dorsal thalamus and confabulations: Evidence from a clinical case and combined MRI/DTI study.

    Science.gov (United States)

    Onofrj, Valeria; Delli Pizzi, Stefano; Franciotti, Raffaella; Taylor, John-Paul; Perfetti, Bernardo; Caulo, Massimo; Onofrj, Marco; Bonanni, Laura

    2016-01-01

    The Medio-Dorsal Nuclei (MDN) including the thalamic magnocellular and parvocellular thalamic regions has been implicated in verbal memory function. In a 77 year old lady, with a prior history of a clinically silent infarct of the left MDN, we observed the acute onset of spontaneous confabulations when an isolated new infarct occurred in the right MDN. The patient and five age-matched healthy subjects underwent Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI). The thalamic lesions were localized by overlapping Morel Thalamic Atlas with structural MRI data. DTI was used to assess: i) white matter alterations (Fractional Anisotropy, FA) within fibers connecting the ischemic areas to cortex; ii) the micro-structural damage (Mean Diffusivity) within the thalamic sub-regions defined by their structural connectivity to the Anterior Cingulate Cortex (ACC) and to the temporal lobes. These target regions were chosen because their damage is considered associated with the appearance of confabulations. Thalamic lesions were localized within the parvocellular regions of the right and left MDNs. The structural connectivity study showed that the fiber tracts, connecting the bilaterally damaged thalamic regions with the frontal cortex, corresponded to the anterior thalamic radiations (ATR). FA within these tracts was significantly lower in the patient as compared to controls. Mean diffusivity within the MDNs projecting to Broadman area (BA) 24, BA25 and BA32 of ACC was significantly higher in the patient than in control group. Mean diffusivity values within the MDN projecting to temporal lobes in contrast were not different between patient and controls. Our findings suggest the involvement of bilateral MDNs projections to ACC in the genesis of confabulations and help provide clarity to the longstanding debate on the origin of confabulations.

  9. Contrasting connectivity of the ventralis intermedius and ventralis oralis posterior nuclei of the motor thalamus demonstrated by probabilistic tractography

    DEFF Research Database (Denmark)

    Hyam, Jonathan A; Owen, Sarah L F; Kringelbach, Morten L.

    2012-01-01

    of these nuclei were determined a priori from the literature, namely the primary motor cortex (M1) and contralateral cerebellum for the Vim and M1, the supplementary motor area (SMA) and dorsolateral prefrontal cortex (DLPFC) for the Vop. RESULTS:: Tractogram signal intensity was highest in the DLPFC and SMA...

  10. Deep Brain Stimulation of Medial Dorsal and Ventral Anterior Nucleus of the Thalamus in OCD: A Retrospective Case Series

    OpenAIRE

    Maarouf, Mohammad; Neudorfer, Clemens; El Majdoub, Faycal; Lenartz, Doris; Kuhn, Jens; Sturm, Volker

    2016-01-01

    Background The current notion that cortico-striato-thalamo-cortical circuits are involved in the pathophysiology of obsessive-compulsive disorder (OCD) has instigated the search for the most suitable target for deep brain stimulation (DBS). However, despite extensive research, uncertainty about the ideal target remains with many structures being underexplored. The aim of this report is to address a new target for DBS, the medial dorsal (MD) and the ventral anterior (VA) nucleus of the thalamu...

  11. Deep Brain Stimulation of Medial Dorsal and Ventral Anterior Nucleus of the Thalamus in OCD: A Retrospective Case Series

    National Research Council Canada - National Science Library

    Maarouf, Mohammad; Neudorfer, Clemens; El Majdoub, Faycal; Lenartz, Doris; Kuhn, Jens; Sturm, Volker

    2016-01-01

    ...) has instigated the search for the most suitable target for deep brain stimulation (DBS). However, despite extensive research, uncertainty about the ideal target remains with many structures being underexplored...

  12. Backward Shift of Head Direction Tuning Curves of the Anterior Thalamus: Comparison with CA1 Place Fields

    OpenAIRE

    Yu, Xintian; Yoganarasimha, D.; Knierim, James J.

    2006-01-01

    The head direction cell system of the rat brain is composed of multiple regions associated with the hippocampal formation. The dynamics of head direction tuning curves (HDTCs) were compared with place fields of the hippocampus. In both familiar and cue-altered environments, as a rat ran an increasing number of laps on a circular track, the center of mass (COM) of the HDTC tended to shift backwards, ...

  13. Control of Somatosensory Cortical Processing by Thalamic Posterior Medial Nucleus: A New Role of Thalamus in Cortical Function.

    Directory of Open Access Journals (Sweden)

    Carlos Castejon

    Full Text Available Current knowledge of thalamocortical interaction comes mainly from studying lemniscal thalamic systems. Less is known about paralemniscal thalamic nuclei function. In the vibrissae system, the posterior medial nucleus (POm is the corresponding paralemniscal nucleus. POm neurons project to L1 and L5A of the primary somatosensory cortex (S1 in the rat brain. It is known that L1 modifies sensory-evoked responses through control of intracortical excitability suggesting that L1 exerts an influence on whisker responses. Therefore, thalamocortical pathways targeting L1 could modulate cortical firing. Here, using a combination of electrophysiology and pharmacology in vivo, we have sought to determine how POm influences cortical processing. In our experiments, single unit recordings performed in urethane-anesthetized rats showed that POm imposes precise control on the magnitude and duration of supra- and infragranular barrel cortex whisker responses. Our findings demonstrated that L1 inputs from POm imposed a time and intensity dependent regulation on cortical sensory processing. Moreover, we found that blocking L1 GABAergic inhibition or blocking P/Q-type Ca2+ channels in L1 prevents POm adjustment of whisker responses in the barrel cortex. Additionally, we found that POm was also controlling the sensory processing in S2 and this regulation was modulated by corticofugal activity from L5 in S1. Taken together, our data demonstrate the determinant role exerted by the POm in the adjustment of somatosensory cortical processing and in the regulation of cortical processing between S1 and S2. We propose that this adjustment could be a thalamocortical gain regulation mechanism also present in the processing of information between cortical areas.

  14. Three times as many lamina I neurons project to the periaqueductal gray than to the thalamus : a retrograde tracing study in the cat

    NARCIS (Netherlands)

    Mouton, Leonora J.; Holstege, Gert

    1998-01-01

    The number and distribution of lamina I neurons projecting to the periaqueductal gray (PAG) were examined by a retrograde tracing study in the cat. WGA-HRP injections in the intermediate and caudal FAG resulted in as much as 1600 labeled lamina I neurons throughout the length of the spinal cord,

  15. In cat four times as many lamina I neurons project to the parabrachial nuclei and twice as many to the periaqueductal gray as to the thalamus

    NARCIS (Netherlands)

    Klop, EM; Mouton, LJ; Hulsebosch, R; Boers, J; Holstege, G

    2005-01-01

    The spinothalamic tract, and especially its fibers originating in lamina 1, is the best known pathway for transmission of nociceptive information. On the other hand, different studies have suggested that more lamina I cells project to the parabrachial nuclei (PBN) and periaqueductal gray (PAG) than

  16. Optic nerve, superior colliculus, visual thalamus, and primary visual cortex of the northern elephant seal (Mirounga angustirostris) and California sea lion (Zalophus californianus).

    Science.gov (United States)

    Turner, Emily C; Sawyer, Eva K; Kaas, Jon H

    2017-06-15

    The northern elephant seal (Mirounga angustirostris) and California sea lion (Zalophus californianus) are members of a diverse clade of carnivorous mammals known as pinnipeds. Pinnipeds are notable for their large, ape-sized brains, yet little is known about their central nervous system. Both the northern elephant seal and California sea lion spend most of their lives at sea, but each also spends time on land to breed and give birth. These unique coastal niches may be reflected in specific evolutionary adaptations to their sensory systems. Here, we report on components of the visual pathway in these two species. We found evidence for two classes of myelinated fibers within the pinniped optic nerve, those with thick myelin sheaths (elephant seal: 9%, sea lion: 7%) and thin myelin sheaths (elephant seal: 91%, sea lion: 93%). In order to investigate the architecture of the lateral geniculate nucleus, superior colliculus, and primary visual cortex, we processed brain sections from seal and sea lion pups for Nissl substance, cytochrome oxidase, and vesicular glutamate transporters. As in other carnivores, the dorsal lateral geniculate nucleus consisted of three main layers, A, A1, and C, while each superior colliculus similarly consisted of seven distinct layers. The sea lion visual cortex is located at the posterior side of cortex between the upper and lower banks of the postlateral sulcus, while the elephant seal visual cortex extends far more anteriorly along the dorsal surface and medial wall. These results are relevant to comparative studies related to the evolution of large brains. © 2017 Wiley Periodicals, Inc.

  17. Shaker-related potassium channels in the central medial nucleus of the thalamus are important molecular targets for arousal suppression by volatile general anesthetics.

    Science.gov (United States)

    Lioudyno, Maria I; Birch, Alexandra M; Tanaka, Brian S; Sokolov, Yuri; Goldin, Alan L; Chandy, K George; Hall, James E; Alkire, Michael T

    2013-10-09

    The molecular targets and neural circuits that underlie general anesthesia are not fully elucidated. Here, we directly demonstrate that Kv1-family (Shaker-related) delayed rectifier K(+) channels in the central medial thalamic nucleus (CMT) are important targets for volatile anesthetics. The modulation of Kv1 channels by volatiles is network specific as microinfusion of ShK, a potent inhibitor of Kv1.1, Kv1.3, and Kv1.6 channels, into the CMT awakened sevoflurane-anesthetized rodents. In heterologous expression systems, sevoflurane, isoflurane, and desflurane at subsurgical concentrations potentiated delayed rectifier Kv1 channels at low depolarizing potentials. In mouse thalamic brain slices, sevoflurane inhibited firing frequency and delayed the onset of action potentials in CMT neurons, and ShK-186, a Kv1.3-selective inhibitor, prevented these effects. Our findings demonstrate the exquisite sensitivity of delayed rectifier Kv1 channels to modulation by volatile anesthetics and highlight an arousal suppressing role of Kv1 channels in CMT neurons during the process of anesthesia.

  18. Sub-threshold cross-modal sensory interaction in the thalamus: lemniscal auditory response in the medial geniculate nucleus is modulated by somatosensory stimulation.

    Science.gov (United States)

    Donishi, T; Kimura, A; Imbe, H; Yokoi, I; Kaneoke, Y

    2011-02-03

    Recent studies have highlighted cross-modal sensory modulations in the primary sensory areas in the cortex, suggesting that cross-modal sensory interactions occur at early stages in the hierarchy of sensory processing. Multi-modal sensory inputs from non-lemniscal thalamic nuclei and cortical inputs from the secondary sensory and association areas are considered responsible for the modulations. On the other hand, there is little evidence of cross-sensory modal sensitivities in lemniscal thalamic nuclei. In the present study, we were interested in a possibility that somatosensory stimulation may affect auditory response in the ventral division (MGV) of the medial geniculate nucleus (MG), a lemniscal thalamic nucleus that is considered to be dedicated to auditory uni-modal processing. Experiments were performed on anesthetized rats. Transcutaneous electrical stimulation of the hindpaw, which is thought to evoke nociception and seems unrelated to auditory processing, modulated unit discharges in response to auditory stimulation (noise bursts). The modulation was observed in the MGV and non-lemniscal auditory thalamic nuclei such as the dorsal and medial divisions of the MG. The major effect of somatosensory stimulation was suppression. The most robust suppression was induced by electrical stimuli given simultaneously with noise bursts or preceding noise bursts by 10 to 20 ms. The results indicate that the lemniscal (MGV) and non-lemniscal auditory nuclei are subject to somatosensory influence. In everyday experience intense somatosensory stimuli such as pain interrupt our ongoing hearing or interfere with clear recognition of sound. The modulation of lemniscal auditory response by somatosensory stimulation may underlie such cross-modal disturbance of auditory perception as a form of cross-modal switching of attention. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. Spike-wave discharges in WAG/Rij rats are preceded by delta and theta precursor activity in cortex and thalamus

    NARCIS (Netherlands)

    Luijtelaar, E.L.J.M. van; Hramov, A.E.; Sitnikova, E.Y.; Koronovskii, A.A.

    2011-01-01

    Objective: In order to unravel the mechanisms underlying the "sudden" onset of spontaneous absences in genetically prone subjects, we investigated the immediate precursors of spike-wave discharges (SWDs) produced in cortico-thalamo-cortical neuronal networks. Methods: A time-frequency analysis of

  20. Tic related local field potentials in the thalamus and the effect of deep brain stimulation in Tourette syndrome: Report of three cases

    NARCIS (Netherlands)

    Bour, L. J.; Ackermans, L.; Foncke, E. M. J.; Cath, D.; van der Linden, C.; Visser Vandewalle, V.; Tijssen, M. A.

    2015-01-01

    Three patients with intractable Tourette syndrome (TS) underwent thalamic deep brain stimulation (DBS). To investigate the role of thalamic electrical activity in tic generation, local field potentials (LFP), EEG and EMG simultaneously were recorded. Event related potentials and event related

  1. Tic related local field potentials in the thalamus and the effect of deep brain stimulation in Tourette syndrome: Report of three cases.

    Science.gov (United States)

    Bour, L J; Ackermans, L; Foncke, E M J; Cath, D; van der Linden, C; Visser Vandewalle, V; Tijssen, M A

    2015-08-01

    Three patients with intractable Tourette syndrome (TS) underwent thalamic deep brain stimulation (DBS). To investigate the role of thalamic electrical activity in tic generation, local field potentials (LFP), EEG and EMG simultaneously were recorded. Event related potentials and event related spectral perturbations of EEG and LFP, event related cross-coherences between EEG/LFP and LFP/LFP were analyzed. As time locking events, the tic onsets were used. Spontaneous tics were compared to voluntary tic mimicking. The effect of tic suppression and DBS on thalamic LFPs was evaluated. All three patients showed time-locked and prior to onset of spontaneous motor tics thalamic synchronization and thalamo-cortical cross-coherence. Also in three patients, not time-locked to motor tics, increased intra-thalamic coherences in the 1-8Hz frequency band were found. In one patient it was demonstrated that voluntary mimicked tics were preceded by premotor cortical and thalamic potentials. In this patient unilateral thalamic DBS contralaterally decreased the background thalamic activity. The present study in three cases with TS shows that spontaneous tics in TS are preceded by repetitive coherent thalamo-cortical discharges, indicating that preceding a tic the basal ganglia circuits are "charged up", ultimately leading to a motor tic. Thalamic LFP recording may lead to more insight in underlying pathophysiological mechanisms in TS. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  2. Tic related local field potentials in the thalamus and the effect of deep brain stimulation in Tourette syndrome: Report of three cases

    NARCIS (Netherlands)

    Bour, L.J.; Ackermans, L.; Foncke, E.M.J.; Cath, D.; van der Linden, C.; Vandewalle, V.V.; Tijssen, M.A.

    2015-01-01

    Objective: Three patients with intractable Tourette syndrome (TS) underwent thalamic deep brain stimulation (DBS). To investigate the role of thalamic electrical activity in tic generation, local field potentials (LFP), EEG and EMG simultaneously were recorded. Methods: Event related potentials and

  3. Tic related local field potentials in the thalamus and the effect of deep brain stimulation in Tourette syndrome : Report of three cases

    NARCIS (Netherlands)

    Bour, L. J.; Ackermans, L.; Foncke, E. M. J.; Cath, D.; van der Linden, C.; Vandewalle, V. Visser; Tijssen, M. A.

    Objective: Three patients with intractable Tourette syndrome (TS) underwent thalamic deep brain stimulation (DBS). To investigate the role of thalamic electrical activity in tic generation, local field potentials (LFP), EEG and EMG simultaneously were recorded. Methods: Event related potentials and

  4. Thalamus and language: interface with attention, memory and executive functions Tálamo e linguagem: interface com atenção, memória e funções executivas

    Directory of Open Access Journals (Sweden)

    Marcia Radanovic

    2003-03-01

    Full Text Available Subcortical structures are in a strategic functional position within the cognitive networks. Their lesion can interfere with a great number of functions. We studied six patients with thalamic vascular lesions (three left sided, two right sided and one bilateral, to characterize their repercussion in the communicative abilities and the interface between language alterations and other cognitive abilities, as attention, memory and frontal executive. All patients were evaluated through a functional interview (discourse analysis, and the following batteries: Boston Diagnostic Aphasia Examination, Boston Naming Test, Token Test, Benton Visual Retention Test, Trail Making, Wisconsin Card Sorting and frontal scripts. All patients performed MRI and five underwent SPECT. Results show that these patients present impairment in several cognitive domains, especially attention and executive functions (working memory, planning and self-monitoring; those with right lesions have an additional visuospatial impairment. Such alterations interfere with language abilities, and this fact must be considered in the rehabilitation efforts.As estruturas subcorticais ocupam posições funcionais estratégicas nas redes cognitivas. Sua lesão pode interferir com grande número de funções. Estudamos seis pacientes com lesão vascular talâmica (três à esqueda, dois à direita e um bilateral, para caracterizar a repercussão da lesão nas suas habilidades comunicativas e a interface entre alterações de linguagem e outras habilidades cognitivas, como atenção, memória e executivas frontais. Os pacientes foram avaliados através de entrevista funcional (análise do discurso, testes de Boston para Diagnóstico da Afasia, Nomeação Boston, Token, Múltipla Escolha de Benton, Trail Making, Wisconsin Card Sorting e scripts frontais. Todos os pacientes realizaram ressonância magnética encefálica (RM e cinco realizaram SPECT. Os resultados mostram que os pacientes apresentam prejuízo em diversos domínios cognitivos, especialmente atenção e funções executivas (memória operacional, planejamento e automonitoração; nos lesados à direita, ocorre prejuízo visuoespacial associado. Tais alterações repercutem nas habilidades de linguagem, o que deve ser levado em conta para reabilitação.

  5. Disinhibition of the mediodorsal thalamus induces Fos-like immunoreactivity in both pyramidal and GABA-containing neurons in the medial prefrontal cortex of rats, but does not affect prefrontal extracellular GABA levels

    NARCIS (Netherlands)

    Bubser, M; Brabander, J.M; Timmerman, W; Feenstra, M.G P; Erdtsieck-Ernste, E.B H W; Rinkens, A; van Uum, J.F M; Westerink, B.H.C.

    1998-01-01

    Stimulation of the mediodorsal and midline thalamic nuclei excites cortical neurons and induces c-fos expression in the prefrontal cortex. Data in the literature data suggest that pyramidal neurons are the most likely cellular targets. In order to determine whether cortical interneurons are also

  6. Synaptic Plasticity and NO-cGMP-PKG Signaling Coordinately Regulate ERK-Driven Gene Expression in the Lateral Amygdala and in the Auditory Thalamus Following Pavlovian Fear Conditioning

    Science.gov (United States)

    Ota, Kristie T.; Monsey, Melissa S.; Wu, Melissa S.; Young, Grace J.; Schafe, Glenn E.

    2010-01-01

    We have recently hypothesized that NO-cGMP-PKG signaling in the lateral nucleus of the amygdala (LA) during auditory fear conditioning coordinately regulates ERK-driven transcriptional changes in both auditory thalamic (MGm/PIN) and LA neurons that serve to promote pre- and postsynaptic alterations at thalamo-LA synapses, respectively. In the…

  7. The deep stimulation of the sub-thalamus nucleus affects the limbic and associative circuits: a study in {sup 18}F-F.D.G. -PET in the Parkinson disease;La stimulation profonde du noyau sous thalamique affecte les circuits limbique et associatif: une etude en 18FDG-TEP dans la maladie de Parkinson

    Energy Technology Data Exchange (ETDEWEB)

    Le Jeune, F.; Garin, E. [Centre Eugene-Marquis, Servive de medecine nucleaire, 35 - Rennes (France); Le Jeune, F.; Peron, J.; Grandjean, D.; Drapier, S.; Haegelen, C.; Garin, E.; Millet, B.; Verin, M. [Universite de Rennes-1, URU comportement et noyaux gris centraux, 35 - Rennes (France); Peron, J.; Drapier, S.; Haegelen, C.; Verin, M. [CHU Pontchaillou, service de neurologie, 35 - Rennes (France); Grandjean, D. [University of Genova, Swiss Center for Affective Sciences, Geneve (Switzerland); Millet, B. [Centre hospitalier Guillaume-Regnier, service de psychiatrie adulte, 35 - Rennes (France)

    2010-05-15

    The purpose of this study is to highlight the changes in brain metabolism in {sup 18}F.D.G.-PET to improve understanding of the non-motor functional role .This study confirms the non-motor functional role of the sub thalamic nucleus (S.T.N.) in limbic and associative circuits in humans.These results provide working hypotheses to study the correlations between neuropsychological alterations clinically diagnosed and cerebral metabolism in order to identify the neural circuits involved. (N.C.)

  8. Abnormal Ocular Movement With Executive Dysfunction and Personality Change in Subject With Thalamic Infarction: A Case Report.

    Science.gov (United States)

    Kim, Ee Jin; Kim, Myeong Ok; Kim, Chang Hwan; Joa, Kyung Lim; Jung, Han Young

    2015-12-01

    The thalamus, located between the cerebrum and midbrain, is a nuclear complex connected to the cerebral cortex that influences motor skills, cognition, and mood. The thalamus is composed of 50-60 nuclei and can be divided into four areas according to vascular supply. In addition, it can be divided into five areas according to function. Many studies have reported on a thalamic infarction causing motor or sensory changes, but few have reported on behavioral and executive aspects of the ophthalmoplegia of the thalamus. This study reports a rare case of a paramedian thalamus infarction affecting the dorsomedial area of the thalamus, manifesting as oculomotor nerve palsy, an abnormal behavioral change, and executive dysfunction. This special case is presented with a review of the anatomical basis and function of the thalamus.

  9. African Journal of Neurological Sciences - 2009 Vol. 28 No 1

    African Journals Online (AJOL)

    Departments of Otolaryngology, Mayo Clinic Arizona. E-Mail Contact - LYONS Mark K. : lyons.mark2 (at) mayo (dot) edu. Mots-clés: Stimulation cérébrale profonde, tremblement essentiel, dysphonie spasmodique, Thalamus. Keywords: Deep brain stimulation, Essential tremor, Spasmodic dysphonia, Thalamus. RESUME.

  10. Enlargement of thalamic nuclei in Tourette syndrome

    DEFF Research Database (Denmark)

    Miller, Ann M; Bansal, Ravi; Hao, Xuejun

    2010-01-01

    CONTEXT: The basal ganglia and thalamus together connect in parallel closed-loop circuits with the cortex. Previous imaging studies have shown modifications of the basal ganglia and cortical targets in individuals with Tourette syndrome (TS), but less is known regarding the role of the thalamus...... in motor circuits to attenuate the severity of tics....

  11. Effects of dose-dependent levels of isoflurane on cerebral blood flow in healthy subjects studied using positron emission tomography

    DEFF Research Database (Denmark)

    Schlünzen, L; Cold, G E; Rasmussen, Mads

    2006-01-01

    in the insula and decreased in the thalamus, the cuneus and lingual gyrus. Compared with flow distribution in awake volunteers, 1 MAC of isoflurane significantly raised relative activity in the anterior cingulate and insula regions. In contrast, a significant relative flow reduction was identified......, insula regions, cerebellum, lingual gyrus and thalamus....

  12. Neural correlates of consciousness

    African Journals Online (AJOL)

    thalamus for arousal; that basic cognition is supported by recurrent electrical activity between the cortex and the thalamus at ... problem of cognitive binding and the role of attention are briefly addressed and it is shown that consciousness depends on a multitude of .... experience emotions, the way we join perceptions into a.

  13. Enlargement of thalamic nuclei in Tourette syndrome

    DEFF Research Database (Denmark)

    Miller, Ann M; Bansal, Ravi; Hao, Xuejun

    2010-01-01

    CONTEXT: The basal ganglia and thalamus together connect in parallel closed-loop circuits with the cortex. Previous imaging studies have shown modifications of the basal ganglia and cortical targets in individuals with Tourette syndrome (TS), but less is known regarding the role of the thalamus...

  14. Stereotactische neurochirurgie bij de behandeling van de ziekte van Parkinson

    NARCIS (Netherlands)

    Speelman, J. D.; Esselink, R. A.; Schuurman, P. R.; de Bie, R. M.; Bosch, D. A.

    2001-01-01

    Three target structures are available in stereotactic surgery for Parkinson's disease: the thalamus, the globus pallidus and the subthalamic nucleus. The subthalamic nucleus appears to be the most promising structure. However, the thalamus can be considered in the case of an incapacitating tremor

  15. Development of thalamocortical connectivity during infancy and its cognitive correlations.

    Science.gov (United States)

    Alcauter, Sarael; Lin, Weili; Smith, J Keith; Short, Sarah J; Goldman, Barbara D; Reznick, J Steven; Gilmore, John H; Gao, Wei

    2014-07-02

    Although commonly viewed as a sensory information relay center, the thalamus has been increasingly recognized as an essential node in various higher-order cognitive circuits, and the underlying thalamocortical interaction mechanism has attracted increasing scientific interest. However, the development of thalamocortical connections and how such development relates to cognitive processes during the earliest stages of life remain largely unknown. Leveraging a large human pediatric sample (N = 143) with longitudinal resting-state fMRI scans and cognitive data collected during the first 2 years of life, we aimed to characterize the age-dependent development of thalamocortical connectivity patterns by examining the functional relationship between the thalamus and nine cortical functional networks and determine the correlation between thalamocortical connectivity and cognitive performance at ages 1 and 2 years. Our results revealed that the thalamus-sensorimotor and thalamus-salience connectivity networks were already present in neonates, whereas the thalamus-medial visual and thalamus-default mode network connectivity emerged later, at 1 year of age. More importantly, brain-behavior analyses based on the Mullen Early Learning Composite Score and visual-spatial working memory performance measured at 1 and 2 years of age highlighted significant correlations with the thalamus-salience network connectivity. These results provide new insights into the understudied early functional brain development process and shed light on the behavioral importance of the emerging thalamocortical connectivity during infancy. Copyright © 2014 the authors 0270-6474/14/349067-09$15.00/0.

  16. Differential modulation of thalamo-parietal interactions by varying depths of isoflurane anesthesia.

    Directory of Open Access Journals (Sweden)

    Dongrae Cho

    Full Text Available The thalamus is thought to relay peripheral sensory information to the somatosensory cortex in the parietal lobe. Long-range thalamo-parietal interactions play an important role in inducing the effect of anesthetic. However, whether these interaction changes vary with different levels of anesthesia is not known. In the present study, we investigated the influence of different levels of isoflurane-induced anesthesia on the functional connectivity between the thalamus and the parietal region. Microelectrodes were implanted in rats to record local field potentials (LFPs. The rats underwent different levels of isoflurane anesthesia [deep anesthesia: isoflurane (ISO 2.5 vol%, light anesthesia (ISO 1 vol%, awake, and recovery state] and LFPs were recorded from four different brain areas (left parietal, right parietal, left thalamus, and right thalamus. Partial directed coherence (PDC was calculated for these areas. With increasing depth of anesthesia, the PDC in the thalamus-to-parietal direction was significantly increased mainly in the high frequency ranges; however, in the parietal-to-thalamus direction, the increase was mainly in the low frequency band. For both directions, the PDC changes were prominent in the alpha frequency band. Functional interactions between the thalamus and parietal area are augmented proportionally to the anesthesia level. This relationship may pave the way for better understanding of the neural processing of sensory inputs from the periphery under different levels of anesthesia.

  17. Functional network interactions during sensorimotor synchronization in musicians and non-musicians.

    Science.gov (United States)

    Krause, Vanessa; Schnitzler, Alfons; Pollok, Bettina

    2010-08-01

    Precise timing as determined by sensorimotor synchronization is crucial for a wide variety of activities. Although it is well-established that musicians show superior timing as compared to non-musicians, the neurophysiological foundations - in particular the underlying functional brain network - remain to be characterized. To this end, drummers, professional pianists and non-musicians performed an auditory synchronization task while neuromagnetic activity was measured using a 122-channel whole-head magnetoencephalography (MEG) system. The underlying functional brain network was determined using the beamformer approach Dynamic Imaging of Coherent Sources (DICS). Behaviorally, drummers performed less variably than non-musicians. Neuromagnetic analysis revealed a cerebello-thalamo-cortical network in all subjects comprising bilateral primary sensorimotor cortices (S1/M1), contralateral supplementary motor and premotor regions (SMA and PMC), thalamus, posterior parietal cortex (PPC), ipsilateral cerebellum and bilateral auditory cortices. Stronger PMC-thalamus and PPC-thalamus interactions at alpha and beta frequencies were evident in drummers as compared to non-musicians. In professional pianists stronger PMC-thalamus interaction as compared to non-musicians at beta frequency occurred. The present data suggest that precise timing is associated with increased functional interaction within a PMC-thalamus-PPC network. The PMC-thalamus connectivity at beta frequency might be related to musical expertise, whereas the PPC-thalamus interaction might have specific relevance for precise timing. Copyright 2010 Elsevier Inc. All rights reserved.

  18. [Diversity in thalamic relay neurons: evidence for "bottom-up" and "top-down" information flow in thalamocortical pathways].

    Science.gov (United States)

    Clascá, Francisco; Rubio-Garrido, Pablo; Galazo, María J; Porrero, César

    2009-01-01

    Thalamocortical (TC) pathways are still mainly understood as the gateway for ascending sensory-motor information into the cortex. However, it is now clear that a great many TC cells are involved in interactions between cortical areas via the thalamus. We review recent data, including our own, which demonstrate the generalized presence in rodent thalamus of two major TC cell types characterized, among other features, by their axon development, arborization and laminar targeting in the cortex. Such duality may allow inputs from thalamus to access cortical circuits via "bottom-up"-wired axon arbors or via "top-down"-wired axon arbors.

  19. A positron emission tomography study of wind-up pain in chronic postherniotomy pain

    DEFF Research Database (Denmark)

    Kupers, Ron; Lonsdale, Markus Georg; Aasvang, Eske Kvanner

    2011-01-01

    -painful von Frey stimulation revealed that the former more strongly activated contralateral secondary somatosensory cortex, insula, anterior cingulate cortex, right dorsolateral prefrontal cortex, thalamus and cerebellum. In addition, wind-up pain also activated the sublenticular extended amygdala (SLEA...

  20. Experiment list: SRX019333 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  1. Experiment list: SRX019332 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  2. Experiment list: SRX1029470 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  3. Experiment list: SRX1029471 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  4. Experiment list: SRX1029474 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  5. Experiment list: SRX019341 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  6. Experiment list: SRX189396 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ion fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from... numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  7. Experiment list: SRX019336 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  8. Experiment list: SRX1029473 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  9. Experiment list: SRX019339 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  10. Experiment list: SRX1029472 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  11. Experiment list: SRX1029467 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  12. Experiment list: SRX1029463 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  13. Experiment list: SRX019337 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  14. Experiment list: SRX1029465 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  15. Experiment list: SRX019335 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  16. Experiment list: SRX1029464 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  17. Experiment list: SRX019334 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  18. Experiment list: SRX1029466 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  19. Experiment list: SRX019338 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  20. Experiment list: SRX019343 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  1. Experiment list: SRX1029469 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from nu...merous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  2. Experiment list: SRX733655 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available rojection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fiber...s from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affer

  3. Experiment list: SRX019331 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  4. Experiment list: SRX019340 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...erous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affere

  5. Experiment list: SRX733654 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available rojection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fiber...s from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affer

  6. Effects of subthalamic nucleus lesions and stimulation upon corticostriatal afferents in the 6-hydroxydopamine-lesioned rat

    National Research Council Canada - National Science Library

    Walker, Ruth H; Moore, Cindy; Davies, Georgia; Dirling, Lisa B; Koch, Rick J; Meshul, Charles K

    2012-01-01

    ... or lesioning of the subthalamic nucleus (STN). The major glutamatergic afferent pathways to the striatum are from the cortex and thalamus, and are thus likely to be sources of striatal neuronally-released glutamate...

  7. Identifying brain nociceptive information transmission in patients with chronic somatic pain

    Directory of Open Access Journals (Sweden)

    Don A. Davis

    2016-10-01

    Conclusion:. Collectively, the results suggest that, across 2 types of chronic pain, nociceptive-specific information is relayed through the spinothalamic pathway to the lateral thalamus, potentiated by pronociceptive descending modulation, and interrupting cortical cognitive processes.

  8. Thalamic involvement in a patient with kernicterus

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Yueksel [Department of Pediatrics, Marmara University School of Medicine, Istanbul (Turkey); Ekinci, Gazanfer [Department of Radiology, Marmara University School of Medicine, Istanbul (Turkey)

    2002-07-01

    We report the MR imaging findings of a 16-month-old boy with dyskinetic cerebral palsy resulting from kernicterus. T2-weighted images showed symmetric bilateral hyperintensity in the thalamus in addition to the globus pallidus. (orig.)

  9. T-type calcium channels cause bursts of spikes in motor but not sensory thalamic neurons during mimicry of natural patterns of synaptic input

    Science.gov (United States)

    Kim, Haram R.; Hong, Su Z.; Fiorillo, Christopher D.

    2015-01-01

    Although neurons within intact nervous systems can be classified as ‘sensory’ or ‘motor,’ it is not known whether there is any general distinction between sensory and motor neurons at the cellular or molecular levels. Here, we extend and test a theory according to which activation of certain subtypes of voltage-gated ion channel (VGC) generate patterns of spikes in neurons of motor systems, whereas VGC are proposed to counteract patterns in sensory neurons. We previously reported experimental evidence for the theory from visual thalamus, where we found that T-type calcium channels (TtCCs) did not cause bursts of spikes but instead served the function of ‘predictive homeostasis’ to maximize the causal and informational link between retinogeniculate excitation and spike output. Here, we have recorded neurons in brain slices from eight sensory and motor regions of rat thalamus while mimicking key features of natural excitatory and inhibitory post-synaptic potentials. As predicted by theory, TtCC did cause bursts of spikes in motor thalamus. TtCC-mediated responses in motor thalamus were activated at more hyperpolarized potentials and caused larger depolarizations with more spikes than in visual and auditory thalamus. Somatosensory thalamus is known to be more closely connected to motor regions relative to auditory and visual thalamus, and likewise the strength of its TtCC responses was intermediate between these regions and motor thalamus. We also observed lower input resistance, as well as limited evidence of stronger hyperpolarization-induced (‘H-type’) depolarization, in nuclei closer to motor output. These findings support our theory of a specific difference between sensory and motor neurons at the cellular level. PMID:26582654

  10. T-type calcium channels cause bursts of spikes in motor but not sensory thalamic neurons during mimicry of natural patterns of synaptic input.

    Science.gov (United States)

    Kim, Haram R; Hong, Su Z; Fiorillo, Christopher D

    2015-01-01

    Although neurons within intact nervous systems can be classified as 'sensory' or 'motor,' it is not known whether there is any general distinction between sensory and motor neurons at the cellular or molecular levels. Here, we extend and test a theory according to which activation of certain subtypes of voltage-gated ion channel (VGC) generate patterns of spikes in neurons of motor systems, whereas VGC are proposed to counteract patterns in sensory neurons. We previously reported experimental evidence for the theory from visual thalamus, where we found that T-type calcium channels (TtCCs) did not cause bursts of spikes but instead served the function of 'predictive homeostasis' to maximize the causal and informational link between retinogeniculate excitation and spike output. Here, we have recorded neurons in brain slices from eight sensory and motor regions of rat thalamus while mimicking key features of natural excitatory and inhibitory post-synaptic potentials. As predicted by theory, TtCC did cause bursts of spikes in motor thalamus. TtCC-mediated responses in motor thalamus were activated at more hyperpolarized potentials and caused larger depolarizations with more spikes than in visual and auditory thalamus. Somatosensory thalamus is known to be more closely connected to motor regions relative to auditory and visual thalamus, and likewise the strength of its TtCC responses was intermediate between these regions and motor thalamus. We also observed lower input resistance, as well as limited evidence of stronger hyperpolarization-induced ('H-type') depolarization, in nuclei closer to motor output. These findings support our theory of a specific difference between sensory and motor neurons at the cellular level.

  11. Zinc-finger genes Fez and Fez-like function in the establishment of diencephalon subdivisions.

    Science.gov (United States)

    Hirata, Tsutomu; Nakazawa, Masato; Muraoka, Osamu; Nakayama, Rika; Suda, Yoko; Hibi, Masahiko

    2006-10-01

    Fez and Fez-like (Fezl) are zinc-finger genes that encode transcriptional repressors expressed in overlapping domains of the forebrain. By generating Fez;Fezl-deficient mice we found that a redundant function of Fez and Fezl is required for the formation of diencephalon subdivisions. The caudal forebrain can be divided into three transverse subdivisions: prethalamus (also called ventral thalamus), thalamus (dorsal thalamus) and pretectum. Fez;Fezl-deficient mice showed a complete loss of prethalamus and a strong reduction of the thalamus at late gestation periods. Genetic marker analyses revealed that during early diencephalon patterning in Fez;Fezl-deficient mice, the rostral diencephalon (prospective prethalamus) did not form and the caudal diencephalon (prospective thalamus and pretectum) expanded rostrally. Fez;Fezl-deficient mice also displayed defects in the formation of the zona limitans intrathalamica (ZLI), which is located on the boundary between the prethalamus and thalamus. Fez and Fezl are expressed in the region rostral to the rostral limit of Irx1 expression, which marks the prospective position of the ZLI. Transgene-mediated misexpression of Fezl or Fez caudal to the ZLI repressed the caudal diencephalon fate and affected the formation of the Shh-expressing ZLI. These data indicate that Fez and Fezl repress the caudal diencephalon fate in the rostral diencephalon, and ZLI formation probably depends on Fez/Fezl-mediated formation of diencephalon subdivisions.

  12. Characteristics of local field potentials correlate with pain relief by deep brain stimulation.

    Science.gov (United States)

    Huang, Yongzhi; Luo, Huichun; Green, Alexander L; Aziz, Tipu Z; Wang, Shouyan

    2016-07-01

    To investigate the link between neuronal activity recorded from the sensory thalamus and periventricular gray/periaqueductal gray (PVAG) and pain relief by deep brain stimulation (DBS). Local field potentials (LFPs) were recorded from the sensory thalamus and PVAG post-operatively from ten patients with neuropathic pain. The LFPs were quantified using spectral and time-frequency analysis, the relationship between the LFPs and pain relief was quantified with nonlinear correlation analysis. The theta oscillations of both sensory thalamus and PVAG correlated inversely with pain relief. The high beta oscillations in the sensory thalamus and the alpha oscillations in the PVAG correlated positively with pain relief. Moreover, the ratio of high-power duration to low-power duration of theta band activity in the sensory thalamus and PVAG correlated inversely with pain relief. The duration ratio at the high beta band in the sensory thalamus correlated positively with pain relief. Our results reveal distinct neuronal oscillations at the theta, alpha, and beta frequencies correlating with pain relief by DBS. The study provides quantitative measures for predicting the outcomes of neuropathic pain relief by DBS as well as potential biomarkers for developing adaptive stimulation strategies. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  13. Thalamic metabolic alterations with cognitive dysfunction in idiopathic trigeminal neuralgia: a multivoxel spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuan; Bao, Faxiu; Ma, Shaohui; Guo, Chenguang; Jin, Chenwang; Zhang, Ming [First Affiliated Hospital of Xi' an Jiaotong University, Department of Medical Imaging, Xi' an, Shaanxi (China); Li, Dan [First Affiliated Hospital of Xi' an Jiaotong University, Department of Respiratory and Critical Care Medicine, Xi' an, Shaanxi (China)

    2014-08-15

    Although abnormalities in metabolite compositions in the thalamus are well described in patients with idiopathic trigeminal neuralgia (ITN), differences in distinct thalamic subregions have not been measured with proton magnetic resonance spectroscopy ({sup 1}H-MRS), and whether there are correlations between thalamic metabolites and cognitive function still remain unknown. Multivoxel MRS was recorded to investigate the metabolic alterations in the thalamic subregions of patients with ITN. The regions of interest were localized in the anterior thalamus (A-Th), intralaminar portion of the thalamus (IL-Th), posterior lateral thalamus (PL-Th), posterior medial thalamus (PM-Th), and medial and lateral pulvinar of the thalamus (PuM-Th and PuL-Th). The N-acetylaspartate to creatine (NAA/Cr) and choline to creatine (Cho/Cr) ratios were measured in the ITN and control groups. Scores of the visual analogue scale (VAS) and the Montreal Cognitive Assessment (MoCA) were analyzed to correlate with the neuroradiological findings. The NAA/Cr ratio in the affected side of PM-Th and PL-Th in ITN patients was statistically lower than that in the corresponding regions of the thalamus in controls. The NAA/Cr ratio in the affected PM-Th was negatively associated with VAS and disease duration. Furthermore, decreases of NAA/Cr and Cho/Cr were detected in the affected side of IL-Th, and lower Cho/Cr was positively correlated with MoCA values in the ITN group. Our result of low level of NAA/Cr in the affected PM-Th probably serves as a marker of the pain-rating index, and decreased Cho/Cr in IL-Th may be an indicator of cognitive disorder in patients with ITN. (orig.)

  14. Projections to the midbrain tectum in Salamandra salamandra L.

    Science.gov (United States)

    Finkenstädt, T; Ebbesson, S O; Ewert, J P

    1983-01-01

    Following unilateral iontophoretic application of HRP into the optic tectum of Salamandra salamandra, retrogradely HRP-filled cells were found bilaterally in the pretectum, tegmentum isthmi, the reticular formation, pars medialis, and in the nucleus vestibularis magnocellularis. The area octavo-lateralis projects only to the caudal part of the tectum. Ipsilateral projections were noted from the dorsal gray columns of the cervical spinal cord, the dorsal tegmentum, the thalamus dorsalis pars medialis, thalamus dorsalis, pars anterior (to the rostral one-third of the tectum), the thalamus ventralis (in its entire rostro-caudal extent), and the preoptico-hypothalamic complex. Retrogradely filled cells were identified in deeper layers of the contralateral tectum. There are two telencephalic nuclei projecting ipsilaterally to the tectum via the lateral forebrain: the ventral part of the lateral pallium, and the posterior strioamygdalar complex.

  15. The deep cerebral stimulation of the under thalamic nucleus modifies the cerebral metabolism in {sup 18}FDG-Tep of obsessive compulsive patients; La stimulation cerebrale profonde du noyau sous thalamique modifie le metabolisme cerebral en 18FDG-TEP des patients obsessionnels compulsifs

    Energy Technology Data Exchange (ETDEWEB)

    Le Jeune, F.; Garin, E. [Service de medecine nucleaire, centre Eugene-Marquis, Rennes, (France); Verin, M.; Peron, J. [service de neurologie, CHU Pontchaillou, Rennes, (France); Mallet, L.; Yelnik, J. [Inserm, Avenir Team, Behavior, Emotion and Basal Ganglia, IFR 70, Pitie-Salpetriere, Paris, (France); Kreps, M.O. [Inserm U796, service de psychiatrie, hopital Sainte-Anne, Paris, (France); Drapier, D.; Millet, B. [service de psychiatrie adulte, centre hospitalier Guillaume-Regnier, Rennes, (France)

    2009-05-15

    The aim of this work was to find again this orbito-frontal hyper metabolism among the resistant obsessive compulsive disorder patients that are going to benefit of a deep cerebral stimulation of the under thalamus nucleus and to demonstrate that this new therapy approach leads a reduction of the metabolism in this area in correlation with the clinical improvement. It is about the first study realized in isotopic functional imaging on ten resistant compulsive disorder patients treated by bilateral deep cerebral stimulation of the under thalamus nucleus. It shows that the treatment efficiency is in relation with a reduction of the glucide metabolism in the right orbito-frontal cortex. It suggests equally that the under thalamus nucleus would be functionally linked to the orbito-frontal cortex. (N.C.)

  16. Intravenous injection of gadobutrol in an epidemiological study group did not lead to a difference in relative signal intensities of certain brain structures after 5 years

    Energy Technology Data Exchange (ETDEWEB)

    Kromrey, Marie-Luise; Liedtke, Kim Rouven; Langner, Soenke; Kirsch, Michael; Kuehn, Jens-Peter [University Medicine Greifswald, Institute of Diagnostic Radiology and Neuroradiology, Greifswald (Germany); Ittermann, Till [University Medicine Greifswald, Institute for Community Medicine, Greifswald (Germany); Weitschies, Werner [University Greifswald, Institute of Biopharmacy and Pharmaceutical Technology, Greifswald (Germany)

    2017-02-15

    To investigate if application of macrocyclic gadolinium-based contrast agents in volunteers is associated with neuronal deposition detected by magnetic resonance imaging in a 5-year longitudinal survey. Three hundred eighty-seven volunteers who participated in a population-based study were enrolled. Subjects underwent plain T1-weighted brain MRI at baseline and 5 years later with identical sequence parameters. At baseline, 271 participants additionally received intravenous injection of the macrocyclic contrast agent gadobutrol (1.5 mmol/kg). A control group including 116 subjects received no contrast agent. Relative signal intensities of thalamus, pallidum, pons and dentate nucleus were compared at baseline and follow-up. No difference in relative signal intensities was observed between contrast group (thalamus, p = 0.865; pallidum, p = 0.263; pons, p = 0.533; dentate nucleus, p = 0.396) and control group (thalamus, p = 0.683; pallidum; p = 0.970; pons, p = 0.773; dentate nucleus, p = 0.232) at both times. Comparison between both groups revealed no significant differences in relative signal intensities (thalamus, p = 0.413; pallidum, p = 0.653; pons, p = 0.460; dentate nucleus, p = 0.751). The study showed no significant change in globus pallidus-to-thalamus or dentate nucleus-to-pons ratios. Five years after administration of a 1.5-fold dose gadobutrol to normal subjects, signal intensity of thalamus, pallidum, pons and dentate nucleus did not differ from participants who had not received gadobutrol. (orig.)

  17. Abnormal medial thalamic metabolism in patients with idiopathic restless legs syndrome.

    Science.gov (United States)

    Rizzo, Giovanni; Tonon, Caterina; Testa, Claudia; Manners, David; Vetrugno, Roberto; Pizza, Fabio; Marconi, Sara; Malucelli, Emil; Provini, Federica; Plazzi, Giuseppe; Montagna, Pasquale; Lodi, Raffaele

    2012-12-01

    Pathophysiology of restless legs syndrome is poorly understood. A role of the thalamus, specifically of its medial portion which is a part of the limbic system, was suggested by functional magnetic resonance imaging and positron emission tomography studies. The aim of this study was to evaluate medial thalamus metabolism and structural integrity in patients with idiopathic restless legs syndrome using a multimodal magnetic resonance approach, including proton magnetic resonance spectroscopy, diffusion tensor imaging, voxel-based morphometry and volumetric and shape analysis. Twenty-three patients and 19 healthy controls were studied in a 1.5 T system. Single voxel proton magnetic resonance spectra were acquired in the medial region of the thalamus. In diffusion tensor examination, mean diffusivity and fractional anisotropy were determined at the level of medial thalamus using regions of interest delineated to outline the same parenchyma studied by spectroscopy. Voxel-based morphometry was performed focusing the analysis on the thalamus. Thalamic volumes were obtained using FMRIB's Integrated Registration and Segmentation Tool software, and shape analysis was performed using the FMRIB Software Library tools. Proton magnetic resonance spectroscopy study disclosed a significantly reduced N-acetylaspartate:creatine ratio and N-acetylaspartate concentrations in the medial thalamus of patients with restless legs syndrome compared with healthy controls (P history of restless legs syndrome (β = -0.49; P = 0.018). On the contrary, diffusion tensor imaging, voxel-based morphometry and volumetric and shape analysis of the thalami did not show differences between the two groups. Proton magnetic resonance spectroscopic findings in patients with restless legs syndrome indicate an involvement of medial thalamic nuclei of a functional nature; however, the other structural techniques of the same region did not show any changes. These findings support the hypothesis

  18. Changes in thalamic connectivity in the early and late stages of amnestic mild cognitive impairment: a resting-state functional magnetic resonance study from ADNI.

    Directory of Open Access Journals (Sweden)

    Suping Cai

    Full Text Available We used resting-state functional magnetic resonance imaging (fMRI to investigate changes in the thalamus functional connectivity in early and late stages of amnestic mild cognitive impairment. Data of 25 late stages of amnestic mild cognitive impairment (LMCI patients, 30 early stages of amnestic mild cognitive impairment (EMCI patients and 30 well-matched healthy controls (HC were analyzed from the Alzheimer's disease Neuroimaging Initiative (ADNI. We focused on the correlation between low frequency fMRI signal fluctuations in the thalamus and those in all other brain regions. Compared to healthy controls, we found functional connectivity between the left/right thalamus and a set of brain areas was decreased in LMCI and/or EMCI including right fusiform gyrus (FG, left and right superior temporal gyrus, left medial frontal gyrus extending into supplementary motor area, right insula, left middle temporal gyrus (MTG extending into middle occipital gyrus (MOG. We also observed increased functional connectivity between the left/right thalamus and several regions in LMCI and/or EMCI including left FG, right MOG, left and right precuneus, right MTG and left inferior temporal gyrus. In the direct comparison between the LMCI and EMCI groups, we obtained several brain regions showed thalamus-seeded functional connectivity differences such as the precentral gyrus, hippocampus, FG and MTG. Briefly, these brain regions mentioned above were mainly located in the thalamo-related networks including thalamo-hippocampus, thalamo-temporal, thalamo-visual, and thalamo-default mode network. The decreased functional connectivity of the thalamus might suggest reduced functional integrity of thalamo-related networks and increased functional connectivity indicated that aMCI patients could use additional brain resources to compensate for the loss of cognitive function. Our study provided a new sight to understand the two important states of aMCI and revealed resting

  19. Changes in thalamic connectivity in the early and late stages of amnestic mild cognitive impairment: a resting-state functional magnetic resonance study from ADNI.

    Science.gov (United States)

    Cai, Suping; Huang, Liyu; Zou, Jia; Jing, Longlong; Zhai, Buzhong; Ji, Gongjun; von Deneen, Karen M; Ren, Junchan; Ren, Aifeng

    2015-01-01

    We used resting-state functional magnetic resonance imaging (fMRI) to investigate changes in the thalamus functional connectivity in early and late stages of amnestic mild cognitive impairment. Data of 25 late stages of amnestic mild cognitive impairment (LMCI) patients, 30 early stages of amnestic mild cognitive impairment (EMCI) patients and 30 well-matched healthy controls (HC) were analyzed from the Alzheimer's disease Neuroimaging Initiative (ADNI). We focused on the correlation between low frequency fMRI signal fluctuations in the thalamus and those in all other brain regions. Compared to healthy controls, we found functional connectivity between the left/right thalamus and a set of brain areas was decreased in LMCI and/or EMCI including right fusiform gyrus (FG), left and right superior temporal gyrus, left medial frontal gyrus extending into supplementary motor area, right insula, left middle temporal gyrus (MTG) extending into middle occipital gyrus (MOG). We also observed increased functional connectivity between the left/right thalamus and several regions in LMCI and/or EMCI including left FG, right MOG, left and right precuneus, right MTG and left inferior temporal gyrus. In the direct comparison between the LMCI and EMCI groups, we obtained several brain regions showed thalamus-seeded functional connectivity differences such as the precentral gyrus, hippocampus, FG and MTG. Briefly, these brain regions mentioned above were mainly located in the thalamo-related networks including thalamo-hippocampus, thalamo-temporal, thalamo-visual, and thalamo-default mode network. The decreased functional connectivity of the thalamus might suggest reduced functional integrity of thalamo-related networks and increased functional connectivity indicated that aMCI patients could use additional brain resources to compensate for the loss of cognitive function. Our study provided a new sight to understand the two important states of aMCI and revealed resting-state fMRI is

  20. Brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) levels in post-mortem brain tissue from patients with depression compared to healthy individuals 

    DEFF Research Database (Denmark)

    Sheldrick, A; Camara, S; Ilieva, M

    2017-01-01

    suggests that antidepressant treatment may improve or normalise cerebral concentrations of neurotrophic factors. Therefore, we examined the concentration of brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) in different brain regions (cortex, cingulate gyrus, thalamus, hippocampus, putamen...... treatment and overall age 84.3±5 years versus 14 unaffected subjects at age 70.3±13.8. We detected significant elevation of BDNF (parietal cortex) and NT3 (parietal, temporal and occipital cortex, cingulate gyrus, thalamus, putamen and nucleus caudatus regions) in MDD patients who received antidepressant...

  1. Factoring the brain signatures of anesthesia concentration and level of arousal across individuals.

    Science.gov (United States)

    Barttfeld, Pablo; Bekinschtein, Tristan A; Salles, Alejo; Stamatakis, Emmanuel A; Adapa, Ram; Menon, David K; Sigman, Mariano

    2015-01-01

    Combining resting-state functional magnetic resonance imaging (fMRI) connectivity and behavioral analysis during sedation, we factored out general effects of the anesthetic drug propofol and a specific index of conscious report, participants' level of responsiveness. The factorial analysis shows that increasing concentration of propofol in blood specifically decreases the connectivity strength of fronto-parietal cortical loops. In contrast, loss of responsiveness is indexed by a functional disconnection between the thalamus and the frontal cortex, balanced by an increase in connectivity strength of the thalamus to the occipital and temporal regions of the cortex.

  2. Neuroprotective profile of pyruvate against ethanol-induced neurodegeneration in developing mice brain.

    Science.gov (United States)

    Ullah, Najeeb; Naseer, Muhammad Imran; Ullah, Ikram; Kim, Tae Hyun; Lee, Hae Young; Kim, Myeong Ok

    2013-12-01

    Exposure to ethanol during developmental stages leads to several types of neurological disorders. Apoptotic neurodegeneration due to ethanol exposure is a main feature in alcoholism. Exposure of developing animals to alcohol induces apoptotic neuronal death and causes fetal alcohol syndrome. In the present study, we observed the possible protective effect of pyruvate against ethanol-induced neurodegeneration. Exposure of developing mice to ethanol (2.5 g/kg) induces apoptotic neurodegeneration and widespread neuronal cell death in the cortex and thalamus. Co-treatment of pyruvate (500 mg/kg) protects neuronal cell against ethanol by the reduced expression of caspase-3 in these brain regions. Immunohistochemical analysis and TUNNEL at 24 h showed that apoptotic cell death induced by ethanol in the cortex and thalamus is reduced by pyruvate. Histomorphological analysis at 24 h with cresyl violet staining also proved that pyruvate reduced the number of neuronal cell loss in the cortex and thalamus. The results showed that ethanol increased the expression of caspase-3 and thus induced apoptotic neurodegeneration in the developing mice cortex and thalamus, while co-treatment of pyruvate inhibits the induction of caspase-3 and reduced the cell death in these brain regions. These findings, therefore, showed that treatment of pyruvate inhibits ethanol-induced neuronal cell loss in the postnatal seven (P7) developing mice brain and may appear as a safe neuroprotectant for treating neurodegenerative disorders in newborns and infants.

  3. Tcf7l2 plays crucial roles in forebrain development through regulation of thalamic and habenular neuron identity and connectivity

    NARCIS (Netherlands)

    Lee, Myungsin; Yoon, Jiyeon; Song, Hobeom; Lee, Bumwhee; Lam, Duc Tri; Yoon, Jaeseung; Baek, Kwanghee; Clevers, Hans; Jeong, Yongsu

    2017-01-01

    The thalamus acts as a central integrator for processing and relaying sensory and motor information to and from the cerebral cortex, and the habenula plays pivotal roles in emotive decision making by modulating dopaminergic and serotonergic circuits. These neural compartments are derived from a

  4. Microstructural changes in the striatum and their impact on motor and neuropsychological performance in patients with multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Michele Cavallari

    Full Text Available Grey matter (GM damage is a clinically relevant feature of multiple sclerosis (MS that has been previously assessed with diffusion tensor imaging (DTI. Fractional anisotropy (FA of the basal ganglia and thalamus might be increased in MS patients, and correlates with disability scores. Despite the established role of the striatum and thalamus in motor control, mood and cognition, the impact of DTI changes within these structures on motor and neuropsychological performance has not yet been specifically addressed in MS. We investigated DTI metrics of deep GM nuclei and their potential association with mobility and neuropsychological function. DTI metrics from 3T MRI were assessed in the caudate, putamen, and thalamus of 30 MS patients and 10 controls. Sixteen of the patients underwent neuropsychological testing. FA of the caudate and putamen was higher in MS patients compared to controls. Caudate FA correlated with Expanded Disability Status Scale score, Ambulation Index, and severity of depressive symptomatology. Putamen and thalamus FA correlated with deficits in memory tests. In contrast, cerebral white matter (WM lesion burden showed no significant correlation with any of the disability, mobility and psychometric parameters. Our findings support evidence of FA changes in the basal ganglia in MS patients, as well as deep GM involvement in disabling features of MS, including mobility and cognitive impairment. Deep GM FA appears to be a more sensitive correlate of disability than WM lesion burden.

  5. examining the relationship between anxiety disorders and depression

    African Journals Online (AJOL)

    Enrique

    Medial thalamus nuclei. Abnormal NA. Frontal lobe system regulation +. ↑Deep white matter serotonin, GABA ± lesions in bipolars dopamine. ↓Frontal blood flow. ↓GH response to clonidine. ↓TSH + PRL response to TRH in. 1/3. Antidepressants downregulate beta adrenoreceptors,. 5HT1+2 receptor + increase GABA-B.

  6. Kleine-Levin syndrome as a neuropsychiatric presentation: A case ...

    African Journals Online (AJOL)

    2014-07-02

    Jul 2, 2014 ... with reported perfusion deficits in the right or left thalamus, hypothalamus, basal ganglia, mesial temporal lobes and frontal lobe.[2,10] In our case, a SPECT done on patient A during an episode showed reduced perfusion to the right frontal, paracingular, posterior parietal, right parieto-occipital cortices and ...

  7. An unusual case of human rabies thought to be of chiropteran origin

    African Journals Online (AJOL)

    1971-07-17

    Jul 17, 1971 ... fifth cranial nerve, right frontal lobe, right parietal lobe, right occipital lobe, pons, medulla, vermis cerebelli, cere- bellum, nucleus dentatus, hippocampus, substantia nigra, basal ganglia, thalamus and corpora mamalaria. Sections were also prepared from various levels of the cervical thoracic, lumbar and ...

  8. Brain correlates of spike and wave discharges in GLUT1 deficiency syndrome

    Directory of Open Access Journals (Sweden)

    Anna Elisabetta Vaudano

    2017-01-01

    Conclusion: The BOLD dynamics related to GSWD in GLUT1DS are substantially different from typical GGE showing the former an increased activity in the premotor-striatal network and a decrease in the thalamus. The revealed hemodynamic maps might represent imaging biomarkers of GLUT1DS, being potentially useful for a precocious diagnosis of this genetic disorder.

  9. Thalamic noradrenaline in Parkinson's disease: deficits suggest role in motor and non-motor symptoms.

    Science.gov (United States)

    Pifl, Christian; Kish, Stephen J; Hornykiewicz, Oleh

    2012-11-01

    The thalamus occupies a pivotal position within the corticobasal ganglia-cortical circuits. In Parkinson's disease (PD), the thalamus exhibits pathological neuronal discharge patterns, foremost increased bursting and oscillatory activity, which are thought to perturb the faithful transfer of basal ganglia impulse flow to the cortex. Analogous abnormal thalamic discharge patterns develop in animals with experimentally reduced thalamic noradrenaline; conversely, added to thalamic neuronal preparations, noradrenaline exhibits marked antioscillatory and antibursting activity. Our study is based on this experimentally established link between noradrenaline and the quality of thalamic neuronal discharges. We analyzed 14 thalamic nuclei from all functionally relevant territories of 9 patients with PD and 8 controls, and measured noradrenaline with high-performance liquid chromatography with electrochemical detection. In PD, noradrenaline was profoundly reduced in all nuclei of the motor (pallidonigral and cerebellar) thalamus (ventroanterior: -86%, P = .0011; ventrolateral oral: -87%, P = .0010; ventrolateral caudal: -89%, P = .0014): Also, marked noradrenaline losses, ranging from 68% to 91% of controls, were found in other thalamic territories, including associative, limbic and intralaminar regions; the primary sensory regions were only mildly affected. The marked noradrenergic deafferentiation of the thalamus discloses a strategically located noradrenergic component in the overall pathophysiology of PD, suggesting a role in the complex mechanisms involved with the genesis of the motor and non-motor symptoms. Our study thus significantly contributes to the knowledge of the extrastriatal nondopaminergic mechanisms of PD with direct relevance to treatment of this disorder. Copyright © 2012 Movement Disorder Society.

  10. Neonatal 6-hydroxydopamine treatment: Noradrenaline levels and in vitro 3H-catecholamine synthesis in discrete brain regions of adult rats

    NARCIS (Netherlands)

    Versteeg, D.H.G.; Ree, J.M. van; Provoost, Abraham P.; Jong, Wybren de

    1974-01-01

    Endogenous noradrenaline levels are elevated in medulla oblongata, mesencephalon, pons and thalamus of adult rats which had been treated with 6-hydroxydopamine on days 1, 2, 8 and 15 after birth. Levels in spinal cord, cerebellum, hippocampus/amygdala and cortex are depressed, whereas no significant

  11. Left Dorsomedial Thalamic Damage Impairs Verbal Recall More Than Recognition: A Case Report.

    Science.gov (United States)

    Ruggeri, Massimiliano

    2016-09-01

    Damage to the dorsomedial thalamus usually leads to impaired episodic memory, attention, and executive function, but the role of the dorsomedial thalamus in memory processing is still not fully understood. Clinical evidence is inconclusive about whether dorsomedial thalamic damage impairs recall or whether it impairs recognition. I report a unique patient who suffered a cardioembolic stroke in the paramedian artery territory, caused by a patent foramen ovale. He was left with a chronic ischemic lesion centered in the parvocellular and, to a lesser extent, the magnocellular portions of the left dorsomedial thalamic nucleus, and marginally involving the midline and intralaminar nuclei. A year after the stroke, the patient's neuropsychological assessment showed a selective verbal memory deficit with greater loss of recall than recognition. His memory was normal when he was given semantically encoded material. His test results showed that damage to the left dorsomedial thalamic nucleus might affect both his recall and recognition because of the involvement of the parvocellular and magnocellular portions, respectively. The results also suggest that the left dorsomedial thalamus is involved in the encoding of verbal material. This case report highlights the role that the left dorsomedial thalamus plays in processing memory specific to verbal material. The findings point to the differential contribution of the dorsomedial parvocellular nucleus to recall, and support the theory that prefrontal strategic memory is enabled by adequate encoding of information through thalamocortical connectivity with the dorsolateral prefrontal cortex.

  12. Multiple intracerebral lesions in a young male

    African Journals Online (AJOL)

    CD4T cell count was 22cells/μL. Chest X-ray and ultra- sound of the abdomen were normal. MRI brain (Figure 1) showed multiple ill-defined and nodular enhancing lesions in bilateral supratentorial and infratentorial neuroparenchyma. Involvement of bilat- eral basal ganglia, thalamus and brainstem was noted. Gram stain ...

  13. Aphasia following left thalamic hemorrhage. A study by Western Aphasia Battery and single photon emission CT

    Energy Technology Data Exchange (ETDEWEB)

    Makishita, Hideo; Miyasaka, Motomaro; Tanizaki, Yoshio; Yanagisawa, Nobuo; Sugishita, Morihiro

    1984-07-01

    A report is given of 7 patients with left thalamic hemorrhage in the chronic stage (from 1.5 months to 4.5 months) in which language disorders were examined by Western Aphasia Battery (WAB) and cerebral blood flow was measured by single photon emission CT. Examination of language by WAB revealed 4 aphasics out of 7 cases, and 3 patients had no language deficit. The patient with Wernicke's aphasia showed low density area only in the left posterior thalamus in X-ray CT, and revealed severe low blood flow area extending to left temporal lobe in emission CT. In the case with transcortical sensory aphasia, although X-ray CT showed no obvious low density area, emission CT revealed moderate low flow area in the left temporooccipital region and low blood flow at the left thalamus. In one of the two patients classified as anomic aphasia, emission CT showed slight low flow area at the temporo-occipital region similar to the case with transcortical sensory aphasia. In another case with anomic aphasia there was a wide low density area all over the left thalamus and midline shift to the right in X-ray CT, and emission CT showed severe low blood flow in the same region spreading widely toward the cerebral surface. In all of the 3 patients without aphasia, emission CT showed low flow region restricted to the left thalamus.

  14. Noradrenergic deficits in Parkinson's disease

    DEFF Research Database (Denmark)

    Nahimi, A.; Sommerauer, M.; Ostergaard, K.

    2017-01-01

    Objectives: In vitro studies suggest that noradrenergic projections from locus coeruleus to subcortical and cortical brain structures, e.g., thalamus, undergo severe neurodegeneration in Parkinson’s disease (PD). Loss of noradrenergic projections may alter oscillatory activity that in turn may...

  15. Neurochemical and Behavioral Features in Genetic Absence Epilepsy and in Acutely Induced Absence Seizures

    NARCIS (Netherlands)

    Bazyan, A.S.; Luijtelaar, E.L.J.M. van

    2013-01-01

    The absence epilepsy typical electroencephalographic pattern of sharp spikes and slow waves (SWDs) is considered to be due to an interaction of an initiation site in the cortex and a resonant circuit in the thalamus. The hyperpolarization-activated cyclic nucleotide-gated cationic Ih pacemaker

  16. Whole-brain structural connectivity in dyskinetic cerebral palsy and its association with motor and cognitive function

    NARCIS (Netherlands)

    Ballester-Plané, Júlia; Schmidt, Ruben; Laporta-Hoyos, Olga; Junqué, Carme; Vázquez, Élida; Delgado, Ignacio; Zubiaurre-Elorza, Leire; Macaya, Alfons; Póo, Pilar; Toro, Esther; de Reus, Marcel A.|info:eu-repo/dai/nl/413970728; van den Heuvel, Martijn P.|info:eu-repo/dai/nl/304820466; Pueyo, Roser

    2017-01-01

    Dyskinetic cerebral palsy (CP) has long been associated with basal ganglia and thalamus lesions. Recent evidence further points at white matter (WM) damage. This study aims to identify altered WM pathways in dyskinetic CP from a standardized, connectome-based approach, and to assess

  17. Role of radiology in psychiatry: a review | Abiodun | East African ...

    African Journals Online (AJOL)

    MRI studies in these patients confirm significant differences in ventricular volume and medial temporal structures. ... patients include altered cerebral blood flow and metabolism in the pre-frontal cortex, anterior cingulate, caudate nucleus, amygdala and thalamus, suggesting abnormal interactions in several brain regions.

  18. Amygdala and heart rate variability responses from listening to emotionally intense parts of a story

    DEFF Research Database (Denmark)

    Wallentin, Mikkel; Nielsen, Andreas Højlund; Vuust, Peter

    2011-01-01

    correspondence across participants between intensity ratings and HRV measurements obtained during fMRI. With this ecologically valid stimulus we found that narrative intensity was accompanied by activation in temporal cortices, medial geniculate nuclei in the thalamus and amygdala, brain regions that are all...

  19. The music of your emotions: neural substrates involved in detection of emotional correspondence between auditory and visual music actions.

    Directory of Open Access Journals (Sweden)

    Karin Petrini

    Full Text Available In humans, emotions from music serve important communicative roles. Despite a growing interest in the neural basis of music perception, action and emotion, the majority of previous studies in this area have focused on the auditory aspects of music performances. Here we investigate how the brain processes the emotions elicited by audiovisual music performances. We used event-related functional magnetic resonance imaging, and in Experiment 1 we defined the areas responding to audiovisual (musician's movements with music, visual (musician's movements only, and auditory emotional (music only displays. Subsequently a region of interest analysis was performed to examine if any of the areas detected in Experiment 1 showed greater activation for emotionally mismatching performances (combining the musician's movements with mismatching emotional sound than for emotionally matching music performances (combining the musician's movements with matching emotional sound as presented in Experiment 2 to the same participants. The insula and the left thalamus were found to respond consistently to visual, auditory and audiovisual emotional information and to have increased activation for emotionally mismatching displays in comparison with emotionally matching displays. In contrast, the right thalamus was found to respond to audiovisual emotional displays and to have similar activation for emotionally matching and mismatching displays. These results suggest that the insula and left thalamus have an active role in detecting emotional correspondence between auditory and visual information during music performances, whereas the right thalamus has a different role.

  20. Beneficial effects of TCP on soman intoxication in guinea pigs : seizures, brain damage and learning behaviour

    NARCIS (Netherlands)

    Groot, D.M.G. de; Bierman, E.P.B.; Bruijnzeel, P.L.B.; Carpentier, P.; Kulig, B.M.; Lallement, G.; Melchers, B.P.C.; Philippens, I.H.C.H.M.; Huygevoort, A.H.B.M. van

    2001-01-01

    Poisoning with the potent nerve agent soman produces a cascade of central nervous system (CNS) effects characterized by severe convulsions and eventually death. In animals that survive a soman intoxication, lesions in the amygdala, piriform cortex, hippocampus and thalamus can be observed. In order

  1. Perceptual Fading without Retinal Adaptation

    Science.gov (United States)

    Hsieh, Po-Jang; Colas, Jaron T.

    2012-01-01

    A retinally stabilized object readily undergoes perceptual fading and disappears from consciousness. This startling phenomenon is commonly believed to arise from local bottom-up sensory adaptation to edge information that occurs early in the visual pathway, such as in the lateral geniculate nucleus of the thalamus or retinal ganglion cells. Here…

  2. Structural Connectivity in Gilles de la Tourette Syndrome

    Directory of Open Access Journals (Sweden)

    Ana B Chelse

    2015-04-01

    Full Text Available Investigators from Centre de Reference National Maladie Rare ‘Syndrome Gilles de la Tourette’ and Sorbonne University report white matter abnormalities in the pathways connecting the cerebral cortex, basal ganglia, and thalamus in a group of 49 adults with Tourette syndrome (TS.

  3. Experiment list: SRX1177279 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibe...rs from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affe...rents of visual, auditory, and somatic origin. 39950544,88.9,39.6,11150 GSM1866052:

  4. Experiment list: SRX1177280 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibe...rs from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affe...rents of visual, auditory, and somatic origin. 20954559,90.9,6.4,25708 GSM1866053:

  5. Experiment list: SRX1029468 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available s projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fi...EM as well as cortical afferents of visual, auditory, and somatic origin. 14652286,100.0,2.8,209 GSM1688589:...bers from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYST

  6. Experiment list: SRX1177281 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibe...rs from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical affe...rents of visual, auditory, and somatic origin. 50682354,95.8,10.4,1925 GSM1866054:

  7. Thalamic morphology in schizophrenia and schizoaffective disorder.

    Science.gov (United States)

    Smith, Matthew J; Wang, Lei; Cronenwett, Will; Mamah, Daniel; Barch, Deanna M; Csernansky, John G

    2011-03-01

    Biomarkers are needed that can distinguish between schizophrenia and schizoaffective disorder to inform the ongoing debate over the diagnostic boundary between these two disorders. Neuromorphometric abnormalities of the thalamus have been reported in individuals with schizophrenia and linked to core features of the disorder, but have not been similarly investigated in individuals with schizoaffective disorder. In this study, we examine whether individuals with schizoaffective disorder have a pattern of thalamic deformation that is similar or different to the pattern found in individuals with schizophrenia. T1-weighted magnetic resonance images were collected from individuals with schizophrenia (n = 47), individuals with schizoaffective disorder (n = 15), and controls (n = 42). Large-deformation, high-dimensional brain mapping was used to obtain three-dimensional surfaces of the thalamus. Multiple analyses of variance were used to test for group differences in volume and measures of surface shape. Individuals with schizophrenia or schizoaffective disorder have similar thalamic volumes. Thalamic surface shape deformation associated with schizophrenia suggests selective involvement of the anterior and posterior thalamus, while deformations in mediodorsal and ventrolateral regions were observed in both groups. Schizoaffective disorder had distinct deformations in medial and lateral thalamic regions. Abnormalities distinct to schizoaffective disorder suggest involvement of the central and ventroposterior medial thalamus which may be involved in mood circuitry, dorsolateral nucleus which is involved in recall processing, and the lateral geniculate nucleus which is involved in visual processing. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Effects of subanaesthetic and anaesthetic doses of sevoflurane on regional cerebral blood flow in healthy volunteers. A positron emission tomographic study

    DEFF Research Database (Denmark)

    Schlünzen, L; Vafaee, M S; Cold, G E

    2004-01-01

    in the thalamus. At the last level (0.4 MAC vs. 1 MAC) the rCBF was increased in the insula and decreased in the posterior cingulate, the lingual gyrus, precuneus and in the frontal cortex. CONCLUSION: At sevoflurane concentrations at 0.7% and 2.0% a significant decrease in relative rCBF was detected...

  9. Impact of the erythropoietin-derived peptide mimetic Epotris on the histopathological consequences of status epilepticus

    DEFF Research Database (Denmark)

    Zellinger, Christina; Seeger, Natalie; Hadamitzky, Martin

    2011-01-01

    the microglial response caused by prolonged seizure activity in the thalamus but not in other brain regions. The study renders support that the Epotris' sequences from binding site 2 in helix C of Epo play a role in receptor interaction and cytokine function. In addition, the data demonstrate that Epotris can...

  10. Receptor May Underlie Gender Differences in Response to Smoking Cessation Therapy

    Science.gov (United States)

    ... generates feelings of pleasure and reward and regulates cognition and movement. The thalamus, where women showed β 2 *-nAChR changes, regulates the flow of sensory information between the cortex and areas of the brain associated with emotion and motivation. Figure 2. Male and Female Smokers ...

  11. Functional characterization and expression of thalamic GABAB receptors in a rodent model of Parkinson’s disease

    NARCIS (Netherlands)

    Groote, C. de; Wüllner, U.; Löschmann, P.-A.; Luiten, P.G.M.; Klockgether, T.

    1999-01-01

    Increased GABAergic neurotransmission of the basal ganglia output nuclei projecting to the motor thalamus is thought to contribute to the pathophysiology of Parkinson’s disease. We investigated the functional role of thalamic GABAB receptors in a rodent model of Parkinson’s disease. First, we

  12. Functional characterization and expression of thalamic GABA(B) receptors in a rodent model of Parkinson's disease

    NARCIS (Netherlands)

    de Groote, C; Wullner, U; Loschmann, PA; Luiten, PGM; Klockgether, T

    1999-01-01

    Increased GABAergic neurotransmission of the basal ganglia output nuclei projecting to the motor thalamus is thought to contribute to the pathophysiology of Parkinson's disease. We investigated the functional role of thalamic GABA(B) receptors in a rodent model of Parkinson's disease. First, we

  13. Neuroanatomical considerations of isolated hearing loss in thalamic hemorrhage

    Directory of Open Access Journals (Sweden)

    Nitin Agarwal, M.D.

    2016-12-01

    Conclusion: Presumably, this neurological deficit was caused by a hypertensive hemorrhage in the posterior right thalamus. The following case and discussion will review the potential neuroanatomical pathways that we suggest could make isolated hearing loss be part of a “thalamic syndrome.”

  14. Spinal cord stimulation modulates cerebral neurobiology: a proton magnetic resonance spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Moens, Maarten [Universitair Ziekenhuis Brussel, Department of Neurosurgery and Center for Neuroscience, Brussels (Belgium); Marien, Peter [ZNA Middelheim General Hospital, Department of Neurology, Antwerp (Belgium); Vrije Universiteit Brussel, Department of Clinical and Experimental Neurolinguistics, Brussels (Belgium); Brouns, Raf; Smedt, Ann de [Universitair Ziekenhuis Brussel, Neurology and Center for Neuroscience, Brussels (Belgium); Poelaert, Jan [Universitair Ziekenhuis Brussel, Anesthesiology, Brussels (Belgium); Buyl, Ronald [Vrije Universiteit Brussel, Department of Biostatistics and Medical Informatics, Brussels (Belgium); Droogmans, Steven [Universitair Ziekenhuis Brussel, Cardiology, Brussels (Belgium); Schuerbeek, Peter van [Universitair Ziekenhuis Brussel, Radiology, Brussels (Belgium); Sunaert, Stefan [Katholieke Universiteit Leuven, Department of Radiology, UZ Leuven, Leuven (Belgium); Nuttin, Bart [Katholieke Universiteit Leuven, Neurosurgery, UZ Leuven, Leuven (Belgium)

    2013-08-15

    Although spinal cord stimulation (SCS) is a widely used treatment for chronic neuropathic pain secondary to spinal surgery, little is known about the underlying physiological mechanisms. The primary aim of this study is to investigate the neural substrate underlying short-term SCS by means of {sup 1}H MR spectroscopy with short echo time, in 20 patients with failed back surgery syndrome. Marked increase of {gamma}-aminobutyric acid (GABA) and decrease in glucose in the ipsilateral thalamus were found between baseline situation without SCS and after 9' of SCS, indicating the key role of the ipsilateral thalamus as a mediator of chronic neuropathic pain. In addition, this study also showed a progressive decrease in glucose in the ipsilateral thalamus over time, which is in line with the findings of previous studies reporting deactivation in the ipsilateral thalamic region. The observation of GABA increase and glucose decrease over time in the ipsilateral thalamus may be the causal mechanism of the pain relief due to SCS or an epiphenomenon. (orig.)

  15. Effects of Intralaminar Thalamic Stimulation on Language Functions

    Science.gov (United States)

    Bhatnagar, Subhash C.; Mandybur, George T.

    2005-01-01

    Fifteen neurosurgical subjects, who were undergoing thalamic chronic electrode implants as a treatment for dyskinesia and chronic pain, were evaluated on a series of neurolinguistic functions to determine if the stimulation of the centromedianum nucleus of the thalamus affected language and cognitive processing. Analysis of the data revealed that…

  16. The music of your emotions: neural substrates involved in detection of emotional correspondence between auditory and visual music actions.

    Science.gov (United States)

    Petrini, Karin; Crabbe, Frances; Sheridan, Carol; Pollick, Frank E

    2011-04-29

    In humans, emotions from music serve important communicative roles. Despite a growing interest in the neural basis of music perception, action and emotion, the majority of previous studies in this area have focused on the auditory aspects of music performances. Here we investigate how the brain processes the emotions elicited by audiovisual music performances. We used event-related functional magnetic resonance imaging, and in Experiment 1 we defined the areas responding to audiovisual (musician's movements with music), visual (musician's movements only), and auditory emotional (music only) displays. Subsequently a region of interest analysis was performed to examine if any of the areas detected in Experiment 1 showed greater activation for emotionally mismatching performances (combining the musician's movements with mismatching emotional sound) than for emotionally matching music performances (combining the musician's movements with matching emotional sound) as presented in Experiment 2 to the same participants. The insula and the left thalamus were found to respond consistently to visual, auditory and audiovisual emotional information and to have increased activation for emotionally mismatching displays in comparison with emotionally matching displays. In contrast, the right thalamus was found to respond to audiovisual emotional displays and to have similar activation for emotionally matching and mismatching displays. These results suggest that the insula and left thalamus have an active role in detecting emotional correspondence between auditory and visual information during music performances, whereas the right thalamus has a different role.

  17. Brain structure in bipolar disorder : A longitudinal neuroimaging study in twins

    NARCIS (Netherlands)

    Bootsman, F

    2016-01-01

    In this longitudinal twin study, the goal was to ascertain the extent to which BD shows abnormalities in subcortical and cortical brain regions at baseline and over time. Baseline assessments in this study revealed that BD was associated with smaller volumes of the thalamus, putamen and nucleus

  18. Case of herpes simplex encephalitis(HSE) with a thalamic lesion

    Energy Technology Data Exchange (ETDEWEB)

    Fujimori, K.; Koike, R.; Yuasa, T.; Miyatake, T.; Ito, J.

    1987-02-01

    A case of herpes simplex encephalitis (HSE) with thalamic involvement was reported. The patient, a 27-year-old man, was admitted because of abnormal behavior and fever. He exhibited a disturbance of consciousness, meningial signs, and hyperreflexia. A CT scan of the head revealed diffuse brain edema. Acute encephalitis, especially HSE, was suspected, and so the intravenous administration of acyclovir and steroid therapy were started. The titer of herpes simplex Type 1 virus, as measured by CF and ELISA, was found to have increased amounts of serum and cerebrospinal fluid. 5 days after the onset, his consciousness worsened. He could not tell his name and scarely opened his eyes upon pain stimulation. A CT scan at this time showed low-density lesions in the left thalamus, cingulate gyrus, and the posterior portion of the putamen. About 5 days later, his consciousness level was increased, but he was mute. This symptom was thought to be thalamic aphasia, which might be correlative with the low-density lesions shown in the left thalamus by the CT scan. About 30 days after the onset of the disease, his speech became normal, and a CT scan at 51 hospital days showed no abnormality. The etiology of low-density lesions of the left thalamus in the CT scan is speculated to be as follows: firstly, vascular damage of circulation disturbance, and secondly a special affinity of herpes simplex Type 1 virus to the thalamus.

  19. Reduced Inhibition within Layer IV of Sert Knockout Rat Barrel Cortex is Associated with Faster Sensory Integration

    NARCIS (Netherlands)

    Miceli, S.M.; Nadif Kasri, N.; Joosten, J.; Huang, C.; Kepser, L.; Proville, R.D.R.; Selten, M.M.; Eijs, F. van; Azarfar, A.; Homberg, J.R.; Celikel, T.; Schubert, D.

    2017-01-01

    Neural activity is essential for the maturation of sensory systems. In the rodent primary somatosensory cortex (S1), high extracellular serotonin (5-HT) levels during development impair neural transmission between the thalamus and cortical input layer IV (LIV). Rodent models of impaired 5-HT

  20. Long-Term Synaptic Changes in Two Input Pathways into the Lateral Nucleus of the Amygdala Underlie Fear Extinction

    Science.gov (United States)

    Park, Junchol; Choi, June-Seek

    2010-01-01

    Plasticity in two input pathways into the lateral nucleus of the amygdala (LA), the medial prefrontal cortex (mPFC) and the sensory thalamus, have been suggested to underlie extinction, suppression of a previously acquired conditioned response (CR) following repeated presentations of the conditioned stimulus (CS). However, little is known about…

  1. The distributed somatotopy of tremor: a window into the motor system

    NARCIS (Netherlands)

    Helmich, R.C.G.

    2013-01-01

    The posterior ventrolateral thalamus (VLp) plays a crucial role in Parkinson's tremor and in essential tremor: deep brain stimulation (DBS) of the VLp effectively diminishes both tremor types. Previous research has shown tremor oscillations in the VLp, but the spatial extent and somatotopy of these

  2. Initial and follow-up MRI in a case of early diagnosed Reye's syndrome.

    Science.gov (United States)

    Ozdoba, C; Pfenninger, J; Schroth, G

    1997-07-01

    Early MRI in a case of clinically established Reye's syndrome confirmed CT findings of compressed ventricles and additionally demonstrated signal alterations in the thalamus, mesencephalon and pons. On follow-up MRI the pontine lesion had vanished by 1 week later, while the thalamic lesion persisted for more than 2 months. The patient, however, recovered without neurological sequelae.

  3. Effective connectivity of ascending and descending frontalthalamic pathways during sustained attention: Complex brain network interactions in adolescence.

    Science.gov (United States)

    Jagtap, Pranav; Diwadkar, Vaibhav A

    2016-07-01

    Frontal-thalamic interactions are crucial for bottom-up gating and top-down control, yet have not been well studied from brain network perspectives. We applied network modeling of fMRI signals [dynamic causal modeling (DCM)] to investigate frontal-thalamic interactions during an attention task with parametrically varying levels of demand. fMRI was collected while subjects participated in a sustained continuous performance task with low and high attention demands. 162 competing model architectures were employed in DCM to evaluate hypotheses on bilateral frontal-thalamic connections and their modulation by attention demand, selected at a second level using Bayesian model selection. The model architecture evinced significant contextual modulation by attention of ascending (thalamus → dPFC) and descending (dPFC → thalamus) pathways. However, modulation of these pathways was asymmetric: while positive modulation of the ascending pathway was comparable across attention demand, modulation of the descending pathway was significantly greater when attention demands were increased. Increased modulation of the (dPFC → thalamus) pathway in response to increased attention demand constitutes novel evidence of attention-related gain in the connectivity of the descending attention pathway. By comparison demand-independent modulation of the ascending (thalamus → dPFC) pathway suggests unbiased thalamic inputs to the cortex in the context of the paradigm. Hum Brain Mapp 37:2557-2570, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Effective connectivity of ascending and descending frontal-thalamic pathways during sustained attention: Complex brain network interactions in adolescence

    Science.gov (United States)

    Jagtap, Pranav; Diwadkar, Vaibhav A.

    2016-01-01

    Frontal-thalamic interactions are crucial for bottom-up gating and top-down control, yet have not been well studied from brain network perspectives. We applied network modeling of fMRI signals (Dynamic Causal Modeling; DCM) to investigate frontal-thalamic interactions during an attention task with parametrically varying levels of demand. fMRI was collected while subjects participated in a sustained continuous performance task with low and high attention demands. 162 competing model architectures were employed in DCM to evaluate hypotheses on bilateral frontal-thalamic connections and their modulation by attention demand, selected at a second level using Bayesian Model Selection. The model architecture evinced significant contextual modulation by attention of ascending (thalamus → dPFC) and descending (dPFC → thalamus) pathways. However, modulation of these pathways was asymmetric: While positive modulation of the ascending pathway was comparable across attention demand, modulation of the descending pathway was significantly greater when attention demands were increased. Increased modulation of the (dPFC → thalamus) pathway in response to increased attention demand constitutes novel evidence of attention-related gain in the connectivity of the descending attention pathway. By comparison demand-independent modulation of the ascending (thalamus → dPFC) pathway suggests unbiased thalamic inputs to the cortex in the context of the paradigm. PMID:27145923

  5. Advances in understanding mechanisms of thalamic relays in cognition and behavior.

    Science.gov (United States)

    Mitchell, Anna S; Sherman, S Murray; Sommer, Marc A; Mair, Robert G; Vertes, Robert P; Chudasama, Yogita

    2014-11-12

    The main impetus for a mini-symposium on corticothalamic interrelationships was the recent number of studies highlighting the role of the thalamus in aspects of cognition beyond sensory processing. The thalamus contributes to a range of basic cognitive behaviors that include learning and memory, inhibitory control, decision-making, and the control of visual orienting responses. Its functions are deeply intertwined with those of the better studied cortex, although the principles governing its coordination with the cortex remain opaque, particularly in higher-level aspects of cognition. How should the thalamus be viewed in the context of the rest of the brain? Although its role extends well beyond relaying of sensory information from the periphery, the main function of many of its subdivisions does appear to be that of a relay station, transmitting neural signals primarily to the cerebral cortex from a number of brain areas. In cognition, its main contribution may thus be to coordinate signals between diverse regions of the telencephalon, including the neocortex, hippocampus, amygdala, and striatum. This central coordination is further subject to considerable extrinsic control, for example, inhibition from the basal ganglia, zona incerta, and pretectal regions, and chemical modulation from ascending neurotransmitter systems. What follows is a brief review on the role of the thalamus in aspects of cognition and behavior, focusing on a summary of the topics covered in a mini-symposium held at the Society for Neuroscience meeting, 2014. Copyright © 2014 the authors 0270-6474/14/3415340-07$15.00/0.

  6. Abnormalities in metabolite concentrations in tourette's disorder and obsessive-compulsive disorder-A proton magnetic resonance spectroscopy study.

    Science.gov (United States)

    Fan, Siyan; Cath, Danielle C; van den Heuvel, Odile A; van der Werf, Ysbrand D; Schöls, Caroline; Veltman, Dick J; Pouwels, Petra J W

    2017-03-01

    Abnormal glutamatergic transmission in cortico-striato-thalamo-cortical (CSTC) circuits is thought to be involved in the pathophysiology of Tourette's disorder (TD) and obsessive-compulsive disorder (OCD). Using proton magnetic resonance spectroscopy, the current study aimed to investigate regional concentrations of glutamatergic compounds in TD and OCD patients in comparison to healthy control subjects (HC). Twenty-three TD patients, 20 OCD patients and 22 HC were included. Short echo-time single-voxel 3T MRS was obtained from dorsal anterior cingulate cortex (dACC) and midline bilateral thalamus. The 3-group comparison showed a significant difference in choline concentration in the thalamus. Thalamic choline was highest in OCD patients, showing a significant difference with TD, and a trend compared to HC (post-hoc analyses). Glutamine in dACC correlated negatively with tic severity scores in TD patients, while glutamate in thalamus correlated positively with anxiety severity scores in OCD patients. These findings suggest subtle differences in metabolites in CSTC areas between TD and OCD. Alterations of choline concentrations seem to be both regional (only in thalamus, not in dACC) and disease specific in OCD pathology. The findings need replication in larger groups, but encourage further research into glutamatergic metabolites in TD and OCD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. ORIGINAL ARTICLE

    African Journals Online (AJOL)

    boaz

    pineal gland and median eminence(3). From here, the trypanosomes invade other brain regions including the thalamus and hypothalamus where they cause inflammatory responses that may lead to disruptions in endogenous circadian rhythms like the sleep/wake cycle. The lateral geniculate nucleus, located in the.

  8. Optogenetic Activation of Presynaptic Inputs in Lateral Amygdala Forms Associative Fear Memory

    Science.gov (United States)

    Kwon, Jeong-Tae; Nakajima, Ryuichi; Hyung-Su, Kim; Jeong, Yire; Augustine, George J.; Han, Jin-Hee

    2014-01-01

    In Pavlovian fear conditioning, the lateral amygdala (LA) has been highlighted as a key brain site for association between sensory cues and aversive stimuli. However, learning-related changes are also found in upstream sensory regions such as thalamus and cortex. To isolate the essential neural circuit components for fear memory association, we…

  9. Large-scale cortico-subcortical functional networks in focal epilepsies: The role of the basal ganglia

    Directory of Open Access Journals (Sweden)

    Eva Výtvarová

    2017-01-01

    Significance: Focal epilepsies affect large-scale brain networks beyond the epileptogenic zones. Cortico-subcortical functional connectivity disturbance was displayed in LTLE, FLE, and POLE. Significant changes in the resting-state functional connectivity between cortical and subcortical structures suggest an important role of the BG and thalamus in focal epilepsies.

  10. Structural changes in cerebellar outflow tracts after thalamotomy in essential tremor

    NARCIS (Netherlands)

    Buijink, Arthur W. G.; Caan, Matthan W. A.; Contarino, M. Fiorella; Schuurman, P. Richard; van den Munckhof, Pepijn; de Bie, Rob M. A.; Olabarriaga, Silvia Delgado; Speelman, Johannes D.; van Rootselaar, Anne-Fleur

    2014-01-01

    This study set out to determine whether structural changes are present outside the thalamus after thalamotomy in patients with essential tremor (ET), specifically in the cerebellorubrothalamic tracts. We hypothesized that diffusion tensor imaging (DTI) would detect these changes. We collected DTI

  11. Experiment list: SRX733653 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available SRX733653 hg19 Unclassified Unclassified Neural Prefrontal Cortex MeSH Description=...rojection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fiber...H3K4me3.NeuN positive; Homo sapiens; ChIP-Seq source_name=prefrontal cortex || facs population=NeuN positive || Sex

  12. fMRI activation during spike and wave discharges evoked by photic stimulation

    DEFF Research Database (Denmark)

    Moeller, Friederike; Siebner, Hartwig R; Ahlgrimm, Nils

    2009-01-01

    (EEG-fMRI) in patients with spontaneous generalised spike-wave discharges (GSW) have revealed activation of the thalamus and deactivation in frontoparietal areas, EEG-fMRI studies on evoked GSW such as PPR are lacking. In this EEG-fMRI study, 30 subjects with reported generalised PPR underwent...

  13. The central oscillatory network of orthostatic tremor.

    Science.gov (United States)

    Muthuraman, Muthuraman; Hellriegel, Helge; Paschen, Steffen; Hofschulte, Frank; Reese, Rene; Volkmann, Jens; Witt, K; Deuschl, G; Raethjen, Jan

    2013-09-01

    Orthostatic tremor (OT) is a movement disorder of the legs and trunk that is present in the standing position but typically absent when sitting. The pathological central network involved in orthostatic tremor is still unknown. In this study we analyzed 15 patients with simultaneous high-resolution electroencephalography and electromyography recording to assess corticomuscular coherence. In 1 patient we were able to simultaneously record the local field potential in the ventrolateral thalamus and electroencephalography. Dynamic imaging of coherent source analysis was used to find the sources in the brain that are coherent with the peripheral tremor signal. When standing, the network for the tremor frequency consisted of unilateral activation in the primary motor leg area, supplementary motor area, primary sensory cortex, two prefrontal/premotor sources, thalamus, and cerebellum for the whole 30-second segment recorded. The source coherence dynamics for the primary leg area and the thalamic source signals with the tibialis anterior muscle showed that they were highly coherent for the whole 30 seconds for the contralateral side but markedly decreased after 15 seconds for the ipsilateral side. The source signal and the recorded thalamus signal followed the same time frequency dynamics of coherence in 1 patient. The corticomuscular interaction in OT follows a consistent pattern with an initially bilateral pattern and then a segregated unilateral pattern after 15 seconds. This may add to the feeling of unsteadiness. It also makes the thalamus unlikely as the main source of orthostatic tremor. © 2013 International Parkinson and Movement Disorder Society.

  14. Differential regional gray matter volumes in patients with on-line game addiction and professional gamers

    Science.gov (United States)

    Han, Doug Hyun; Lyoo, In Kyoon; Renshaw, Perry F.

    2015-01-01

    Patients with on-line game addiction (POGA) and professional video game players play video games for extended periods of time, but experience very different consequences for their on-line game play. Brain regions consisting of anterior cingulate, thalamus and occpito-temporal areas may increase the likelihood of becoming a pro-gamer or POGA. Twenty POGA, seventeen pro-gamers, and eighteen healthy comparison subjects (HC) were recruited. All magnetic resonance imaging (MRI) was performed on a 1.5 Tesla Espree MRI scanner (SIEMENS, Erlangen, Germany). Voxel-wise comparisons of gray matter volume were performed between the groups using the two-sample t-test with statistical parametric mapping (SPM5). Compared to HC, the POGA group showed increased impulsiveness and perseverative errors, and volume in left thalamus gray matter, but decreased gray matter volume in both inferior temporal gyri, right middle occipital gyrus, and left inferior occipital gyrus, compared with HC. Pro-gamers showed increased gray matter volume in left cingulate gyrus, but decreased gray matter volume in left middle occipital gyrus and right inferior temporal gyrus compared with HC. Additionally, the pro-gamer group showed increased gray matter volume in left cingulate gyrus and decreased left thalamus gray matter volume compared with the POGA group. The current study suggests that increased gray matter volumes of the left cingulate gyrus in pro-gamers and of the left thalamus in POGA may contribute to the different clinical characteristics of pro-gamers and POGA. PMID:22277302

  15. Visual and SPM analysis of regional cerebral glucose metabolism in adult patients with neurofibromatosis

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Joon Kee; An, Young Sil; Hong, Seon Pyo; Joh, Chul Woo; Yoon, Seok Nam [Ajou University, School of Medicine, Suwon (Korea, Republic of)

    2005-07-01

    We evaluated the regional cerebral glucose metabolism in adult patients with neurofibromatosis (NF) using visual and SPM analysis, and compared with MRI findings. A total of 11 adult patients with NF type I were prospectively included in the study. All patients underwent F-18 FDG PET and brain MRI within 2 month of each other. All hypometabolic areas on PET were determined visually by 2 nuclear medicine physician and compared with MRI findings. SPM analysis was done using 42 normal controls with p = 0.005. Seven of 11 PET images showed 10 hypometabolic areas and 4 of 11 MRIs showed 6 areas of signal change brain parenchyma. Hypometabolic areas were bilateral thalamus (n=5), left temporal cortex (n=4) and dentate nucleus (n=1). In only 2 lesions (thalamus and dentate nucleus), hypometabolic foci were consistently related to signal change on MRI. SPM analysis revealed significantly decreased area in bilateral thalamus and left temporal cortex. F-18 FDG PET revealed significant hypometabolism in bilateral thalamus and left temporal cortex in adult patients with NF, and it might be helpful in understanding developmental abnormality of NF.

  16. Multimodal target point assessment for stereotactic biopsy in children with diffuse bithalamic astrocytomas.

    Science.gov (United States)

    Messing-Jünger, A M; Floeth, F W; Pauleit, D; Reifenberger, G; Willing, R; Gärtner, J; Coenen, H H; Langen, K J

    2002-08-01

    Diffuse glial tumors with bithalamic involvement are rare in children. Diagnostic assessment can be difficult as the radiological findings can be unspecific. In order to enhance the diagnostic yield metabolic imaging with MRS and PET using FET ( O-(2-[(18)F]fluoroethyl)- L-tyrosine) was performed in two children (2 and 10 years of age). Co-registered images were used for image-guided biopsy, which was planned with neuronavigation and stereotaxy simultaneously. Biopsies from the right thalamus were planned, but locations were changed in both cases after metabolic imaging was available. MRS (thalamic voxel) was typical for a glial tumor in one child. In the older girl FET-PET revealed an unexpected lesion in the left cerebellar hemisphere, with a tumor-to-cortex ratio of 3.8, as against 1.7 in the thalamus. Accordingly, a stereotactic biopsy specimen was taken from the left cerebellar hemisphere, and a final diagnosis of anaplastic astrocytoma was made. The other patient showed a higher uptake (tumor-to-cortex ratio 1.6) in the left dorsal thalamus, compared with bilateral homogeneous hyperintensity of the thalamus structures on MRI. Stereotactic biopsy revealed a low-grade diffuse astrocytoma. Stereotactic biopsy using metabolic imaging and image fusion can enhance the diagnostic yield in cases of diffuse pediatric gliomas disclosing unexpected 'hot spots'.

  17. original articles

    African Journals Online (AJOL)

    antagonists to multiple receptor antagonists. Finally, the atypicality of an agent has entailed a strong ..... thalamus leading to a reduced transmission of sensory information to the cerebral cortex. However, any ..... double-blind comparison between olanzapine and risperidone in the same group of patients" provide evidence ...

  18. Brain Consequences of Spinal Cord Injury with and without Neuropathic Pain: Translating Animal Models of Neuroinflammation onto Human Neural Networks and Back

    Science.gov (United States)

    2016-10-01

    xylazine (Patterson Veterinary ) before systemic perfusion with 4% PFA. The spinal cord and the brain, together with other internal organs were...Positron Emission Tomography, functional Magnetic Resonance Imaging, translational medicine , spinal cord injury, rat, human 16. SECURITY CLASSIFICATION OF...translational medicine , thalamus, sensory cortex, anterior cingulate, resting state functional connectivity, brain structure 3. ACCOMPLISHMENTS

  19. Distribution of PDE8A in the nervous system of the Sprague-Dawley rat

    DEFF Research Database (Denmark)

    Kruse, Lars Schack; Møller, Morten; Kruuse, Christina

    2011-01-01

    immunoreactive neurons were located in the olfactory bulb, the septal area, zona incerta, and reticular nucleus of the thalamus. Less immunoreactivity was seen in the hippocampus and cerebral cortex. Intense staining was detected in both the substantia nigra and the sensory trigeminal nucleus. In cerebellum PDE8...

  20. Review: Neural correlates of consciousness | Negrao | African ...

    African Journals Online (AJOL)

    A basic understanding of consciousness and its neural correlates is of major importance for all clinicians, especially those involved with patients with altered states of consciousness. In this paper it is shown that consciousness is dependent on the brainstem and thalamus for arousal; that basic cognition is supported by ...

  1. Evaluating accuracy of striatal, pallidal, and thalamic segmentation methods: Comparing automated approaches to manual delineation.

    Science.gov (United States)

    Makowski, Carolina; Béland, Sophie; Kostopoulos, Penelope; Bhagwat, Nikhil; Devenyi, Gabriel A; Malla, Ashok K; Joober, Ridha; Lepage, Martin; Chakravarty, M Mallar

    2017-03-01

    Accurate automated quantification of subcortical structures is a greatly pursued endeavour in neuroimaging. In an effort to establish the validity and reliability of these methods in defining the striatum, globus pallidus, and thalamus, we investigated differences in volumetry between manual delineation and automated segmentations derived by widely used FreeSurfer and FSL packages, and a more recent segmentation method, the MAGeT-Brain algorithm. In a first set of experiments, the basal ganglia and thalamus of thirty subjects (15 first episode psychosis [FEP], 15 controls) were manually defined and compared to the labels generated by the three automated methods. Our results suggest that all methods overestimate volumes compared to the manually derived "gold standard", with the least pronounced differences produced using MAGeT. The least between-method variability was noted for the striatum, whereas marked differences between manual segmentation and MAGeT compared to FreeSurfer and FSL emerged for the globus pallidus and thalamus. Correlations between manual segmentation and automated methods were strongest for MAGeT (range: 0.51 to 0.92; pmanual labels and automated methods at the lower end of the distribution (i.e. smaller structures), which was most prominent for bilateral thalamus across automated pipelines, and left globus pallidus for FSL. We then went on to examine volume and shape of the basal ganglia structures using automated techniques in 135 FEP patients and 88 controls. The striatum and globus pallidus were significantly larger in FEP patients compared to controls bilaterally, irrespective of the method used. MAGeT-Brain was more sensitive to shape-based group differences, and uncovered widespread surface expansions in the striatum and globus pallidus bilaterally in FEP patients compared to controls, and surface contractions in bilateral thalamus (FDR-corrected). By contrast, after using a recommended cluster-wise thresholding method, FSL only detected

  2. Using susceptibility-weighted images to quantify iron deposition differences in amnestic mild cognitive impairment and Alzheimer's disease.

    Science.gov (United States)

    Wang, Dan; Zhu, Dan; Wei, Xiao-Er; Li, Yue-Hua; Li, Wen-Bin

    2013-01-01

    To quantify iron deposition in Alzheimer's disease (AD), amnestic mild cognitive impairment (aMCI), and control individuals using susceptibility weighted imaging (SWI). Sixty participants (22 aMCI, 20 AD, 18 normal controls) underwent conventional magnetic resonance imaging (MRI) and SWI using axial/oblique coronal sequences. Phase images were used to calculate bilateral iron deposition in 18 regions of interest (ROI). The radian angle value was calculated and compared between the three participant groups. The difference in radian angle value was significant between the aMCI and control groups in the left (L)-hippocampus, L-head of the caudate nucleus, R-lenticular nucleus, L-lenticular nucleus (P =0.02239, radian angle value was significant between the AD and aMCI groups in the R-cerebellar hemisphere, L-cerebellar hemisphere, R-hippocampus, L-hippocampus, R-red nucleus, R-thalamus, L-thalamus, and splenium of corpus callosum (P =0.02754, 0.01839, 0.00934, 0.04316, 0.02472, 0.00152, <0.001, 0.01448, respectively). Pearson correlation coefficients of the Mini-Mental State Examination score were all significant for the bilateral cerebellar hemisphere, hippocampus, red nucleus, lenticular nucleus, thalamus, R-head of the caudate nucleus, and splenium of corpus callosum. Iron deposition in the hippocampus, head of the caudate nucleuslenticular nucleus, and thalamus are significantly different between individuals with aMCI, AD, and controls. The thalamus is a particularly sensitive area. Using SWI to quantify the iron deposition is a useful tool in detecting aMCI and AD.

  3. In search of neural mechanisms of mirror neuron dysfunction in schizophrenia: resting state functional connectivity approach.

    Science.gov (United States)

    Zaytseva, Yuliya; Bendova, Marie; Garakh, Zhanna; Tintera, Jaroslav; Rydlo, Jan; Spaniel, Filip; Horacek, Jiri

    2015-09-01

    It has been repeatedly shown that schizophrenia patients have immense alterations in goal-directed behaviour, social cognition, and social interactions, cognitive abilities that are presumably driven by the mirror neurons system (MNS). However, the neural bases of these deficits still remain unclear. Along with the task-related fMRI and EEG research tapping into the mirror neuron system, the characteristics of the resting state activity in the particular areas that encompass mirror neurons might be of interest as they obviously determine the baseline of the neuronal activity. Using resting state fMRI, we investigated resting state functional connectivity (FC) in four predefined brain structures, ROIs (inferior frontal gyrus, superior parietal lobule, premotor cortex and superior temporal gyrus), known for their mirror neurons activity, in 12 patients with first psychotic episode and 12 matched healthy individuals. As a specific hypothesis, based on the knowledge of the anatomical inputs of thalamus to all preselected ROIs, we have investigated the FC between thalamus and the ROIs. Of all ROIs included, seed-to-voxel connectivity analysis revealed significantly decreased FC only in left posterior superior temporal gyrus (STG) and the areas in visual cortex and cerebellum in patients as compared to controls. Using ROI-to-ROI analysis (thalamus and selected ROIs), we have found an increased FC of STG and bilateral thalamus whereas the FC of these areas was decreased in controls. Our results suggest that: (1) schizophrenia patients exhibit FC of STG which corresponds to the previously reported changes of superior temporal gyrus in schizophrenia and might contribute to the disturbances of specific functions, such as emotional processing or spatial awareness; (2) as the thalamus plays a pivotal role in the sensory gating, providing the filtering of the redundant stimulation, the observed hyperconnectivity between the thalami and the STGs in patients with schizophrenia

  4. Radiosynthesis and preliminary evaluation of Z.W.-90 and Z.W.-110, two novel acetylenic pyridines for imaging the nicotinic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Kassiou, M.; Giboureau, N. [Sydney Univ., Brain and Mind Research Institute, NSW (Australia); Chellapan, S.; Wei, Z.L.; Kozikowski, A. [Illinois Univ., Chicago, Dept. of Medicinal Chemistry and Pharmacognosy, IL (United States); Henderson, D.; Fulton, R. [RPAH Sydney, Dept. PET and Nuclear Medicine (Australia); Xiao, Y.; Kellar, K. [Georgetown Univ., Dept. of Pharmacology, School of Medicine, Washington, DC (United States); Guilloteau, D.; Emond, P. [Institut National de la Sante et de la Recherche Medicale (INSERM), U619, 37 - Tours (France); Dolle, F. [Service Hospitalier Frederic Joliot, CEA/DSV, Institut d' Imagerie BioMedicale, 91 - Orsay (France)

    2008-02-15

    Central nicotinic acetylcholine receptors (n.A.Ch.R.s) have been implicated in learning memory processes and neuro-psychiatric disorders. Recently it was reported that the introduction of a substituted alkynyl group into the C-5 position of the pyridinyl ring of A-84543, significantly increased the selectivity for the n.A.Ch.R. containing {beta}{sub 2} subunits over {beta}{sub 4} subunits. Two selected candidates, Z.W.-90 and Z.W.-110 were labelled with carbon{sup 11} and evaluated in vivo.{sup 11}C Z.W.-90 penetrated rapidly into the brain, with maximum uptake in the thalamus and cerebellum 2 min post injection followed by clearance. The washout from cerebellum was faster than from thalamus, suggesting that specific binding can be optimally measured at 20 min post injection; Pretreatment of the baboon with nicotine resulted in markedly decreased uptake of the radioligand. {sup 11}C Z.W.-110 also penetrated rapidly into the brain, with a high evident uptake in the thalamus within 5 min. Surprisingly there was also considerable uptake in the striatum. Pretreatment with nicotine resulted in inhibition of uptake of 8 and 1%, in the thalamus and cerebellum, respectively. In pretreatment studies using unlabelled Z.W.-110, 32% inhibition of radioligand uptake was observed in the thalamus and striatum while uptake in the cerebellum was reduced by 24 %.While further work will be necessary in the development of optimal imaging agents for n.A.Ch.Rs, efforts will be made to examine the potential of these newly developed radioligands to serve diagnostic agents in the early detection of neurological disorders. (N.C.)

  5. Prefrontal-Thalamic Anatomical Connectivity and Executive Cognitive Function in Schizophrenia.

    Science.gov (United States)

    Giraldo-Chica, Monica; Rogers, Baxter P; Damon, Stephen M; Landman, Bennett A; Woodward, Neil D

    2018-03-15

    Executive cognitive functions, including working memory, cognitive flexibility, and inhibition, are impaired in schizophrenia. Executive functions rely on coordinated information processing between the prefrontal cortex (PFC) and thalamus, particularly the mediodorsal nucleus. This raises the possibility that anatomical connectivity between the PFC and mediodorsal thalamus may be 1) reduced in schizophrenia and 2) related to deficits in executive function. The current investigation tested these hypotheses. Forty-five healthy subjects and 62 patients with a schizophrenia spectrum disorder completed a battery of tests of executive function and underwent diffusion-weighted imaging. Probabilistic tractography was used to quantify anatomical connectivity between six cortical regions, including PFC, and the thalamus. Thalamocortical anatomical connectivity was compared between healthy subjects and patients with schizophrenia using region-of-interest and voxelwise approaches, and the association between PFC-thalamic anatomical connectivity and severity of executive function impairment was examined in patients. Anatomical connectivity between the thalamus and PFC was reduced in schizophrenia. Voxelwise analysis localized the reduction to areas of the mediodorsal thalamus connected to lateral PFC. Reduced PFC-thalamic connectivity in schizophrenia correlated with impaired working memory but not cognitive flexibility and inhibition. In contrast to reduced PFC-thalamic connectivity, thalamic connectivity with somatosensory and occipital cortices was increased in schizophrenia. The results are consistent with models implicating disrupted PFC-thalamic connectivity in the pathophysiology of schizophrenia and mechanisms of cognitive impairment. PFC-thalamic anatomical connectivity may be an important target for procognitive interventions. Further work is needed to determine the implications of increased thalamic connectivity with sensory cortex. Copyright © 2017 Society of

  6. The role of the thalamic nuclei in recognition memory accompanied by recall during encoding and retrieval: an fMRI study.

    Science.gov (United States)

    Pergola, Giulio; Ranft, Alexander; Mathias, Klaus; Suchan, Boris

    2013-07-01

    The present functional imaging study aimed at investigating the contribution of the mediodorsal nucleus and the anterior nuclei of the thalamus with their related cortical networks to recognition memory and recall. Eighteen subjects performed associative picture encoding followed by a single item recognition test during the functional magnetic resonance imaging session. After scanning, subjects performed a cued recall test using the formerly recognized pictures as cues. This post-scanning test served to classify recognition trials according to subsequent recall performance. In general, single item recognition accompanied by successful recall of the associations elicited stronger activation in the mediodorsal nucleus of the thalamus and in the prefrontal cortices both during encoding and retrieval compared to recognition without recall. In contrast, the anterior nuclei of the thalamus were selectively active during the retrieval phase of recognition followed by recall. A correlational analysis showed that activation of the anterior thalamus during retrieval as assessed by measuring the percent signal changes predicted lower rates of recognition without recall. These findings show that the thalamus is critical for recognition accompanied by recall, and provide the first evidence of a functional segregation of the thalamic nuclei with respect to the memory retrieval phase. In particular, the mediodorsal thalamic-prefrontal cortical network is activated during successful encoding and retrieval of associations, which suggests a role of this system in recall and recollection. The activity of the anterior thalamic-temporal network selectively during retrieval predicts better memory performances across subjects and this confirms the paramount role of this network in recall and recollection. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Preclinical evaluation of convection-enhanced delivery of liposomal doxorubicin to treat pediatric diffuse intrinsic pontine glioma and thalamic high-grade glioma.

    Science.gov (United States)

    Sewing, A Charlotte P; Lagerweij, Tonny; van Vuurden, Dannis G; Meel, Michaël H; Veringa, Susanna J E; Carcaboso, Angel M; Gaillard, Pieter J; Peter Vandertop, W; Wesseling, Pieter; Noske, David; Kaspers, Gertjan J L; Hulleman, Esther

    2017-05-01

    OBJECTIVE Pediatric high-grade gliomas (pHGGs) including diffuse intrinsic pontine gliomas (DIPGs) are primary brain tumors with high mortality and morbidity. Because of their poor brain penetrance, systemic chemotherapy regimens have failed to deliver satisfactory results; however, convection-enhanced delivery (CED) may be an alternative mode of drug delivery. Anthracyclines are potent chemotherapeutics that have been successfully delivered via CED in preclinical supratentorial glioma models. This study aims to assess the potency of anthracyclines against DIPG and pHGG cell lines in vitro and to evaluate the efficacy of CED with anthracyclines in orthotopic pontine and thalamic tumor models. METHODS The sensitivity of primary pHGG cell lines to a range of anthracyclines was tested in vitro. Preclinical CED of free doxorubicin and pegylated liposomal doxorubicin (PLD) to the brainstem and thalamus of naïve nude mice was performed. The maximum tolerated dose (MTD) was determined based on the observation of clinical symptoms, and brains were analyzed after H & E staining. Efficacy of the MTD was tested in adult glioma E98-FM-DIPG and E98-FM-thalamus models and in the HSJD-DIPG-007-Fluc primary DIPG model. RESULTS Both pHGG and DIPG cells were sensitive to anthracyclines in vitro. Doxorubicin was selected for further preclinical evaluation. Convection-enhanced delivery of the MTD of free doxorubicin and PLD in the pons was 0.02 mg/ml, and the dose tolerated in the thalamus was 10 times higher (0.2 mg/ml). Free doxorubicin or PLD via CED was ineffective against E98-FM-DIPG or HSJD-DIPG-007-Fluc in the brainstem; however, when applied in the thalamus, 0.2 mg/ml of PLD slowed down tumor growth and increased survival in a subset of animals with small tumors. CONCLUSIONS Local delivery of doxorubicin to the brainstem causes severe toxicity, even at doxorubicin concentrations that are safe in the thalamus. As a consequence, the authors could not establish a therapeutic

  8. Initial experience with single-photon emission tomography using iodine-123-labelled 2[beta]-carbomethoxy-3[beta](4-iodophnyl)tropane in human brain

    Energy Technology Data Exchange (ETDEWEB)

    Kuikka, J.T. (Kuopio Univ. Hospital (Finland). Dept. of Clinical Physiology); Bergstroem, K.A. (Kuopio Univ. Hospital (Finland). Dept. of Clinical Physiology); Vanninen, E. (Kuopio Univ. Hospital (Finland). Dept. of Clinical Physiology); Laulumaa, V. (Kuopio Univ. Hospital (Finland). Dept. of Neurology); Hartikainen, P. (Kuopio Univ. Hospital (Finland). Dept. of Neurology); Laensimies, E. (Kuopio Univ. Hospital (Finland). Dept. of Clinical Physiology)

    1993-09-01

    The iodinated cocaine analogue 2[beta]-carbomethoxy-3[beta]-(4-iodophenyl)tropane ([sup 123]I[beta]-CIT), a new dopamine transporter, was preliminarily tested in human brain. Two normal volunteers and two patients with Parkinson's disease were imaged with a high-resolution single-photon emission tomography scanner. The specific binding of [sup 123]I[beta]-CIT in the basal ganglia and thalamus was high in normal volunteers. In addition, there was relatively intense uptake in the medial prefrontal area. Patients with Parkinson's disease who were older than controls showed significantly lower specific binding in the basal ganglia and thalamus and no uptake in the medial prefrontal cortex. This decrease in the dopamine transporter may be age related. (orig.)

  9. Dysexecutive behaviour following deep brain lesions--a different type of disconnection syndrome?

    Science.gov (United States)

    Krause, Martin; Mahant, Neil; Kotschet, Katya; Fung, Victor S; Vagg, Daniel; Wong, Chong H; Morris, John G L

    2012-01-01

    The suppression of automatic prepotent behaviour in favour of more successful, more 'appropriate' behaviour is the primary function of the frontal lobe. Five frontal-subcortical circuits connect the frontal lobe to the basal ganglia and the thalamus. We report 17 patients with small lesions in the downstream structures of the frontal-subcortical circuits displaying severe dysexecutive behaviour. Positron emission tomography (PET) demonstrated hypometabolism of the frontal lobe in some of these patients. The literature on frontal lobe dysfunction after lesions in the basal ganglia and thalamus is discussed and the semiology of frontal lobe dysfunction in relation to the frontal-subcortical circuits is highlighted. Derived from our findings we suggest a disconnection syndrome of the frontal lobe caused by lesions in the downstream structures of the frontal-subcortical circuits. Crown Copyright © 2011. Published by Elsevier Srl. All rights reserved.

  10. Accelerated forgetting of contextual details due to focal medio-dorsal thalamic lesion

    Directory of Open Access Journals (Sweden)

    Sicong eTu

    2014-09-01

    Full Text Available Effects of thalamic nuclei damage and related white matter tracts on memory performance are still debated. This is particularly evident for the medio-dorsal thalamus which has been less clear in predicting amnesia than anterior thalamus changes. The current study addresses this issue by assessing 7 thalamic stroke patients with consistent unilateral lesions focal to the left medio-dorsal nuclei for immediate and delayed memory performance on standard visual and verbal tests of anterograde memory, and over the long-term (> 24 hrs on an object-location associative memory task. Thalamic patients showed selective impairment to delayed recall, but intact recognition memory. Patients also showed accelerated forgetting of contextual information after a 24 hour delay, compared to controls. Importantly, the mammillothalamic tract was intact in all patients, which suggests a role for the medio-dorsal nuclei in recall and early consolidation memory processes.

  11. Latency modulation of collicular neurons induced by electric stimulation of the auditory cortex in Hipposideros pratti: In vivo intracellular recording.

    Directory of Open Access Journals (Sweden)

    Kang Peng

    Full Text Available In the auditory pathway, the inferior colliculus (IC receives and integrates excitatory and inhibitory inputs from the lower auditory nuclei, contralateral IC, and auditory cortex (AC, and then uploads these inputs to the thalamus and cortex. Meanwhile, the AC modulates the sound signal processing of IC neurons, including their latency (i.e., first-spike latency. Excitatory and inhibitory corticofugal projections to the IC may shorten and prolong the latency of IC neurons, respectively. However, the synaptic mechanisms underlying the corticofugal latency modulation of IC neurons remain unclear. Thus, this study probed these mechanisms via in vivo intracellular recording and acoustic and focal electric stimulation. The AC latency modulation of IC neurons is possibly mediated by pre-spike depolarization duration, pre-spike hyperpolarization duration, and spike onset time. This study suggests an effective strategy for the timing sequence determination of auditory information uploaded to the thalamus and cortex.

  12. Control of Absence Seizures by the Thalamic Feed-Forward Inhibition.

    Science.gov (United States)

    Chen, Mingming; Guo, Daqing; Xia, Yang; Yao, Dezhong

    2017-01-01

    As a subtype of idiopathic generalized epilepsies, absence epilepsy is believed to be caused by pathological interactions within the corticothalamic (CT) system. Using a biophysical mean-field model of the CT system, we demonstrate here that the feed-forward inhibition (FFI) in thalamus, i.e., the pathway from the cerebral cortex (Ctx) to the thalamic reticular nucleus (TRN) and then to the specific relay nuclei (SRN) of thalamus that are also directly driven by the Ctx, may participate in controlling absence seizures. In particular, we show that increasing the excitatory Ctx-TRN coupling strength can significantly suppress typical electrical activities during absence seizures. Further, investigation demonstrates that the GABAA- and GABAB-mediated inhibitions in the TRN-SRN pathway perform combination roles in the regulation of absence seizures. Overall, these results may provide an insightful mechanistic understanding of how the thalamic FFI serves as an intrinsic regulator contributing to the control of absence seizures.

  13. Prostaglandin E2 receptor expression in the rat trigeminal-vascular system and other brain structures involved in pain

    DEFF Research Database (Denmark)

    Myren, Maja; Olesen, Jes; Gupta, Saurabh

    2012-01-01

    receptors in both peripheral and central structures involved in pain transmission and perception in migraine: dura mater, cerebral arteries, trigeminal ganglion, trigeminal nucleus caudalis, periaqueductal grey, thalamus, hypothalamus, cortex, pituitary gland, hippocampus and cerebellum. In the trigeminal......Prostaglandin E(2) (PGE(2)) is considered to be a key mediator in migraine pathophysiology. PGE(2) acts via four receptors (EP(1)-EP(4)) but their distribution in the brain districts implicated in migraine has yet to be delineated. We quantified amount of mRNA and protein expression for the EP...... than in dorsal root ganglia (peripheral control), whereas the EP(2) mRNA and protein were highly abundant in the pituitary gland. EP(3) mRNA was mainly found in thalamus and hypothalamus. The most robust mRNA and protein expression for EP(4) receptor was seen in the dorsal root ganglion. In conclusion...

  14. Altered thalamic connectivity during spontaneous attacks of migraine without aura

    DEFF Research Database (Denmark)

    Amin, Faisal Mohammad; Hougaard, Anders; Magon, Stefano

    2017-01-01

    Background Functional connectivity of brain networks may be altered in migraine without aura patients. Functional magnetic resonance imaging (fMRI) studies have demonstrated changed activity in the thalamus, pons and cerebellum in migraineurs. Here, we investigated the thalamic, pontine and cereb......Background Functional connectivity of brain networks may be altered in migraine without aura patients. Functional magnetic resonance imaging (fMRI) studies have demonstrated changed activity in the thalamus, pons and cerebellum in migraineurs. Here, we investigated the thalamic, pontine...... and cerebellar network connectivity during spontaneous migraine attacks. Methods Seventeen patients with episodic migraine without aura underwent resting-state fMRI scan during and outside of a spontaneous migraine attack. Primary endpoint was a difference in functional connectivity between the attack...

  15. Etiology of phantom limb syndrome: Insights from a 3D default space consciousness model.

    Science.gov (United States)

    Jerath, Ravinder; Crawford, Molly W; Jensen, Mike

    2015-08-01

    In this article, we examine phantom limb syndrome to gain insights into how the brain functions as the mind and how consciousness arises. We further explore our previously proposed consciousness model in which consciousness and body schema arise when information from throughout the body is processed by corticothalamic feedback loops and integrated by the thalamus. The parietal lobe spatially maps visual and non-visual information and the thalamus integrates and recreates this processed sensory information within a three-dimensional space termed the "3D default space." We propose that phantom limb syndrome and phantom limb pain arise when the afferent signaling from the amputated limb is lost but the neural circuits remain intact. In addition, integration of conflicting sensory information within the default 3D space and the loss of inhibitory afferent feedback to efferent motor activity from the amputated limb may underlie phantom limb pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Functional mapping of thalamic nuclei and their integration into cortico-striatal-thalamo-cortical loops via ultra-high resolution imaging- From animal anatomy to in vivo imaging in humans

    Directory of Open Access Journals (Sweden)

    Coraline D. Metzger

    2013-05-01

    Full Text Available The thalamus, a crucial node in the well-described cortico-striatal-thalamo-cortical circuits, has been the focus of functional and structural imaging studies investigating human emotion, cognition and memory. Invasive work in animals and post-mortem investigations have revealed the rich cytoarchitectonics and functional specificity of the thalamus. Given current restrictions in the spatial resolution of non-invasive imaging modalities, there is, however, a translational gap between functional and structural information on these circuits in humans and animals as well as between histological and cellular evidence and their relationship to psychological functioning.With the advance of higher field strengths for MR approaches, better spatial resolution is now available promising to overcome this conceptual problem.We here review these two levels, which exist for both neuroscientific and clinical investigations, and then focus on current attempts to overcome conceptual boundaries of these observations with the help of high-resolution imaging.

  17. Dynamics of absence seizures

    Science.gov (United States)

    Deeba, Farah; Sanz-Leon, Paula; Robinson, Peter

    A neural field model of the corticothalamic system is used to investigate the dynamics of absence seizures in the presence of temporally varying connection strength between the cerebral cortex and thalamus. Variation of connection strength from cortex to thalamus drives the system into seizure once a threshold is passed and a supercritical Hopf bifurcation occurs. The dynamics and spectral characteristics of the resulting seizures are explored as functions of maximum connection strength, time above threshold, and ramp rate. The results enable spectral and temporal characteristics of seizures to be related to underlying physiological variations via nonlinear dynamics and neural field theory. Notably, this analysis adds to neural field modeling of a wide variety of brain activity phenomena and measurements in recent years. Australian Research Council Grants FL1401000225 and CE140100007.

  18. [A new operational method of functional neurosurgery combining micro-recording and MRI stereotaxy for the treatment of Parkinson's disease].

    Science.gov (United States)

    Nishimura, H; Hirai, T

    1993-02-01

    We have developed a new operational method for stereotactic functional neurosurgery using MRI stereotaxy combined with microelectrode recording. MRI stereotaxy shows us the individual variations of thalamic configurations. The tentative target points were determined using the MRI stereotaxy assisted software system which revised the distortion of MRI images. Consequently, the accuracy and safety of the microelectrode recording were increased. This, in turn, increased the accuracy of stereotactic thalamotomy while producing encouraging operational outcomes. The effectiveness of stereotactic thalamotomy for Parkinson's disease was confirmed by these excellent operative results. The symptoms improved and the dosage of medications, including L-DOPA, decreased. Furthermore, our results indicate that the distributing area of deep sensory neurons in the thalamus extended more posteriorly and upward than previously expected. Therefore, the functional and anatomical similarity between the human and monkey thalamus was reaffirmed. In this report, based on the above data, we reevaluated the neural mechanism of tremor and the role of stereotactic functional neurosurgery for Parkinson's disease.

  19. Smoking normalizes cerebral blood flow and oxygen consumption after 12-hour abstention

    DEFF Research Database (Denmark)

    Seyedi Vafaee, Manouchehr; Gjedde, Albert; Imamirad, Nasrin

    2015-01-01

    Acute nicotine administration stimulates [14C]deoxyglucose trapping in thalamus and other regions of rat brain, but acute effects of nicotine and smoking on energy metabolism have rarely been investigated in human brain by positron emission tomography (PET). We obtained quantitative PET...... of the abstention period, global grey-matter CBF and CMRO2 were both reduced by 17% relative to nonsmokers. At 15 minutes after renewed smoking, global CBF had increased insignificantly, while global CMRO2 had increased by 11%. Regional analysis showed that CMRO2 had increased in the left putamen and thalamus......, and in right posterior cortical regions at this time. At 60 and 105 minutes after smoking resumption, CBF had increased by 8% and CMRO2 had increased by 11–12%. Thus, we find substantial and global impairment of CBF/CMRO2 in abstaining smokers, and acute restoration by resumption of smoking. The reduced CBF...

  20. Xenon contrast CT-CBF scanning of the brain differentiates normal age-related changes from multi-infarct dementia and senile dementia of Alzheimer type

    Energy Technology Data Exchange (ETDEWEB)

    Tachibana, H.; Meyer, J.S.; Okayasu, H.; Shaw, T.G.; Kandula, P.; Rogers, R.L.

    1984-07-01

    Local cerebral blood flow (LCBF) and partition coefficients (L lambda) were measured during inhalation of stable xenon gas with serial CT scanning among normal volunteers (N . 15), individuals with multi-infarct dementia (MID, N . 10), and persons with senile dementia of Alzheimer type (SDAT, N . 8). Mean gray matter flow values were reduced in both MID and SDAT. Age-related declines in LCBF values in normals were marked in frontal cortex and basal ganglia. LCBF values were decreased beyond normals in frontal and temporal cortices and thalamus in MID and SDAT, in basal ganglia only in MID. Unlike SDAT and age-matched normals, L lambda values were reduced in fronto-temporal cortex and thalamus in MID. Multifocal nature of lesions in MID was apparent. Coefficients of variation for LCBFs were greater in MID compared with SDAT and/or age-matched normals.

  1. Case of clinical Reye syndrome presenting characteristic CT changes

    Energy Technology Data Exchange (ETDEWEB)

    Hino, Tamaki; Sai, Hoshun; Morikawa, Yuji; Mizuta, Ryuzo (Kyoto Second Red Cross Hospital (Japan)); Okuno, Takehiko

    1984-05-01

    A 9-month-old male infant was admitted to our hospital on the second day of cold like syndrome because of high fever, convulsion, coma, and decerebrate rigidity. Serum GOT, GPT, LDH, and CPK were markedly elevated. Serum ammonia was slightly increased, and hypoglycemia was present. The cerebrospinal fluid showed no pleocytosis, normal sugar content, but increased protein. Thus we made a diagnosis of clinical Reye syndrome according to the criteria by Yamashita, et al. A CT on the day of admission showed symmetrical low-density areas in the posterior fossa and the regions of thalamus. Ringed enhancements were seen around the areas of low density in the thalamus on the twenty-second hospital day. We consider that these lesions may represent the infarction due to obstruction of the thalamoperforant arteries caused by cerebral edema in the early stage of the disease.

  2. Language Disorders due to Posterior System Strokes - An Ignored Dysfunction

    Science.gov (United States)

    ÖZTÜRK, Şerefnur; EGE, Fahrettin; EKMEKÇİ, Hakan

    2014-01-01

    The anterior system is primarily responsible for the clinical picture in a patient that presents with clinical aphasia. However, recent reports have shown that injuries to posterior structures, the cerebellum in particular, may have a role in language processing. Herein, we will look first at the linguistic role of the cerebellum in light of the literature, then of the thalamus and some described clinical syndromes, and finally, specific syndromes resulting from occipital lobe lesions, all of which are supported by the posterior vascular system. The human brain is such a complex organization that in addition to the thalamus and occipital cortex, we can see the involvement of the cerebellum in high cognitive functions. Posterior system strokes may lead to clinical findings of cognitive deficits, including neurolinguistic components. Determining these defects in stroke patients may precipitate changes in current management strategies. PMID:28360648

  3. Fahr’s Disease: A Case Report

    Directory of Open Access Journals (Sweden)

    İlhan Kılınç

    2007-01-01

    Full Text Available Fahr’s disease is characterized with presence of calcifications in basal ganglions, dentate nucleus, and centrum semiovale. Common clinical findings of the disease are Parkinsonism, dystonia, chorea, ataxia, dementia, and mood disorders. We present a patient, in whom a diagnosis of Fahr disease established, with clinical and radiological findings. Neurological and physical exam of the 56 year-old female with complaints of memory loss and speech disorder for one year. Brain CT showed Fahr type calcification in the basal ganglion, thalamus, periventricular white matter, centrum semiovale, and cerebellum. Fahr’s disease must be present in differential diagnosis of patients with calcification in basal ganglion, thalamus, periventricular white matter, centrum semiovale, and cerebellum on CT or MRI that could not be explained otherwise.

  4. Bilateral thalamocortical projection in hedgehogs: evolutionary implications.

    Science.gov (United States)

    Regidor, J; Divac, I

    1992-01-01

    In adult hedgehogs with large unilateral cortical deposits of fluorescent somatopetal tracers, labelled perikarya were found not only in the ipsilateral but also contralateral thalamus. An exceptionally large number of contralaterally labelled neurons was seen in the ventrolateral nucleus, also at a considerable distance from the midline. Deposits of one of two different tracers in the frontoparietal cortex of each hemisphere appear to label different perikarya in each ventrolateral nucleus. This projection to the contralateral cortex in hedgehogs does not resemble thalamo-cortical connections in either adult or developing brains of other mammalian species. Among amniotes, only in pigeons have contralateral projections from the thalamus to the telencephalon been described. The somatosensorimotor system of hedgehogs may be the only known mammalian remnant of primitive vertebrate thalamocortical organization. Whether primitive or derived, the bilateral thalamocortical projection in hedgehogs shows that hedgehog brains cannot be uncritically taken to represent brains of primate ancestors.

  5. Characteristics of thalamic local field potentials in patients with disorders of consciousness.

    Science.gov (United States)

    Huang, Yongzhi; He, Jianghong; Green, Alexander L; Aziz, Tipu Z; Stein, John F; Wang, Shouyan

    2015-08-01

    A functioning thalamus is essential for treatment of patients with disorders of consciousness (DOC) using deep brain stimulation (DBS). This work aims to identify the potential biomarkers related to consciousness from the thalamic deep brain local field potentials (LFPs) in DOC patients. The frequency features of central thalamic LFPs were characterized with spectral analysis. The features were further compared to those of LFPs from the ventroposterior lateral nucleus of the thalamus (VPL) in patients with pain. There are several distinct characteristics of thalamic LFPs found in patients with DOC. The most important feature is the oscillation around 10Hz which could be relevant to the existence of residual consciousness, whereas high power below 8Hz seemed to be associated with loss of consciousness. The invasive deep brain recording tool opens a unique way to explore the brain function in consciousness, awareness and alertness and clarify the potential mechanisms of thalamic stimulation in DOC.

  6. Computational modeling of stuttering caused by impairments in a basal ganglia thalamo-cortical circuit involved in syllable selection and initiation

    Science.gov (United States)

    Civier, Oren; Bullock, Daniel; Max, Ludo; Guenther, Frank H.

    2013-01-01

    A typical white-matter integrity and elevated dopamine levels have been reported for individuals who stutter. We investigated how such abnormalities may lead to speech dysfluencies due to their effects on a syllable-sequencing circuit that consists of basal ganglia (BG), thalamus, and left ventral premotor cortex (vPMC). “Neurally impaired” versions of the neurocomputational speech production model GODIVA were utilized to test two hypotheses: (1) that white-matter abnormalities disturb the circuit via corticostriatal projections carrying copies of executed motor commands, and (2) that dopaminergic abnormalities disturb the circuit via the striatum. Simulation results support both hypotheses: in both scenarios, the neural abnormalities delay readout of the next syllable’s motor program, leading to dysfluency. The results also account for brain imaging findings during dysfluent speech. It is concluded that each of the two abnormality types can cause stuttering moments, probably by affecting the same BG-thalamus-vPMC circuit. PMID:23872286

  7. A quantitative study of regional cerebral blood flow in childhood using {sup 123}I-IMP-SPECT. With emphasis on age-related changes

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Ayame; Kishi, Kazuko; Sejima, Hitoshi; Haneda, Noriyuki; Uchida, Nobue; Sugimura, Kazuro; Ito, Masatoshi; Shiraishi, Hideyuki [Shimane Medical Univ., Izumo (Japan)

    1996-11-01

    Single photon emission computed tomography (SPECT), using N-isopropyl-p-={sup 123}I= iodoamphetamine ({sup 123}I-IMP) was used for quantitative analysis of regional cerebral blood flow (rCBF) on 26 individuals between 0 and 19 years of age. The rCBF showed age-related changes; it was low in early infancy, increased in late infancy through early childhood, and decreased and remained constant after puberty. The rCBF through cerebral cortex varied more greatly than through thalamus and cerebellum, and seemed to depend more closely on age. In the case of 4 months of age rCBF was very low at the frontal region and was very high at the occipital region. In more older cases, rCBF in the cerebral cortex was higher than in the thalamus. In childhood, rCBF was very inconsistent and showed a great inter-individual variance. (author)

  8. Where fMRI and electrophysiology agree to disagree: corticothalamic and striatal activity patterns in the WAG/Rij rat

    Science.gov (United States)

    Mishra, Asht Mangal; Ellens, Damien J.; Schridde, Ulrich; Motelow, Joshua E.; Purcaro, Michael J.; DeSalvo, Matthew N.; Enev, Miro; Sanganahalli, Basavaraju G.; Hyder, Fahmeed; Blumenfeld, Hal

    2012-01-01

    The relationship between neuronal activity and hemodynamic changes plays a central role in functional neuroimaging. Under normal conditions and in neurological disorders such as epilepsy it is commonly assumed that increased functional magnetic resonance imaging (fMRI) signals reflect increased neuronal activity, and that fMRI decreases represent neuronal activity decreases. Recent work suggests these assumptions usually hold true in the cerebral cortex. However, less is known about the basis of fMRI signals from subcortical structures such as the thalamus and basal ganglia. We used Wistar Albino Glaxo rats of Rijswijk (WAG/Rij), an established animal model of human absence epilepsy, to perform fMRI studies with blood oxygen level dependent (BOLD) and cerebral blood volume (CBV) contrasts at 9.4 Tesla; as well as laser Doppler cerebral blood flow (CBF), local field potential (LFP), and multiunit activity (MUA) recordings. We found that during spike-wave discharges, the somatosensory cortex and thalamus showed increased fMRI, CBV, CBF, LFP and MUA signals. However, the caudate-putamen showed fMRI, CBV and CBF decreases despite increases in LFP and MUA signals. Similarly, during normal whisker stimulation the cortex and thalamus showed increases in CBF and MUA, while the caudate-putamen showed decreased CBF with increased MUA. These findings suggest that neuroimaging-related signals and electrophysiology tend to agree in the cortex and thalamus, but disagree in the caudate-putamen. These opposite changes in vascular and electrical activity indicate that caution should be applied when interpreting fMRI signals in both health and disease from the caudate-putamen, as well as possibly from other subcortical structures. PMID:22016539

  9. Synergistic Interactions of Neuroprotective and Neurotrophic Factors Against Sleep Deprivation

    Science.gov (United States)

    2017-03-30

    treatment with ADNP-8 or CNTF-11 restored glutathione peroxidase activity in frontal lobe . Furthermore, immunohistochemistry analysis performed...response…………………………….……36 4.2. Endoplasmic reticulum molecular chaperones response…………….……39 4.3. Neuronal cell death in frontal lobe , thalamus and...deprivation…...25 Figure 10: Blood serum corticosterone concentration after 96h sleep deprivation….25 Figure 11: Neuronal cell death in frontal lobe

  10. Army Medical Research and Materiel Command Resident Research Associateship Program

    Science.gov (United States)

    2017-05-01

    submitted four papers related to sleep and performance/sleep resiliency and genetics (2 published; 2 under review): Journal of Strength & Conditioning...study looking at genetic markers related to sleep resiliency and performance and performance maintenance with caffeine administration. This study is...uptake in the olfactory bulb at 24h following both sPCI and rPCI and depressed uptake in the thalamus, which is present at 3d, resolves, then re

  11. Altered thalamic functional connectivity in multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yaou; Liang, Peipeng; Duan, Yunyun; Huang, Jing; Ren, Zhuoqiong; Jia, Xiuqin [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Dong, Huiqing; Ye, Jing [Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Shi, Fu-Dong [Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052 (China); Butzkueven, Helmut [Department of Medicine, University of Melbourne, Parkville 3010 (Australia); Li, Kuncheng, E-mail: kunchengli55@gmail.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China)

    2015-04-15

    Highlights: •We demonstrated decreased connectivity between thalamus and cortical regions in MS. •Increased intra- and inter-thalamic connectivity was also observed in MS. •The increased functional connectivity is attenuated by increasing disease duration. -- Abstract: Objective: To compare thalamic functional connectivity (FC) in patients with multiple sclerosis (MS) and healthy controls (HC), and correlate these connectivity measures with other MRI and clinical variables. Methods: We employed resting-state functional MRI (fMRI) to examine changes in thalamic connectivity by comparing thirty-five patients with MS and 35 age- and sex-matched HC. Thalamic FC was investigated by correlating low frequency fMRI signal fluctuations in thalamic voxels with voxels in all other brain regions. Additionally thalamic volume fraction (TF), T2 lesion volume (T2LV), EDSS and disease duration were recorded and correlated with the FC changes. Results: MS patients were found to have a significantly lower TF than HC in bilateral thalami. Compared to HC, the MS group showed significantly decreased FC between thalamus and several brain regions including right middle frontal and parahippocampal gyri, and the left inferior parietal lobule. Increased intra- and inter-thalamic FC was observed in the MS group compared to HC. These FC alterations were not correlated with T2LV, thalamic volume or lesions. In the MS group, however, there was a negative correlation between disease duration and inter-thalamic connectivity (r = −0.59, p < 0.001). Conclusion: We demonstrated decreased FC between thalamus and several cortical regions, while increased intra- and inter-thalamic connectivity in MS patients. These complex functional changes reflect impairments and/or adaptations that are independent of T2LV, thalamic volume or presence of thalamic lesions. The negative correlation between disease duration and inter-thalamic connectivity could indicate an adaptive role of thalamus that is

  12. Central Pain Mechanisms and Novel Therapeutic Strategies in a Model of Closed Head Injury

    Science.gov (United States)

    2016-10-01

    concussion syndrome and highly prevalent following traumatic brain injury of all severities . Inflammation is an early promoter of pain, and is proposed...increased in the thalamus, or TNC (p=0.98 and p=0.31, respectively). Chronic group analysis: Increased power after rCHI across several frequency...develop an increase in power over several frequency bands compared to controls. Power is illustrated in three frequency bands: 4-10 Hz, 10-25 Hz, and 40

  13. Memory loss from a subcortical white matter infarct.

    OpenAIRE

    Kooistra, C A; Heilman, K M

    1988-01-01

    Clinical disorders of memory are believed to occur from the dysfunction of either the mesial temporal lobe, the mesial thalamus, or the basal forebrain. Fibre tract damage at the level of the fornix has only inconsistently produced amnesia. A patient is reported who suffered a cerebrovascular accident involving the posterior limb of the left internal capsule that resulted in a persistent and severe disorder of verbal memory. The inferior extent of the lesion effectively disconnected the mesia...

  14. Early and progressive microstructural brain changes in mice overexpressing human alpha-Synuclein detected by diffusion kurtosis imaging

    Czech Academy of Sciences Publication Activity Database

    Khairnar, A.; Rudá-Kučerová, J.; Szabó, N.; Dražanová, Eva; Arab, A.; Hutter-Paier, B.; Neddens, J.; Latta, P.; Starčuk jr., Zenon; Rektorová, I.

    2017-01-01

    Roč. 61, MAR (2017), s. 197-208 ISSN 0889-1591 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk(CZ) LM2015062; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : MRI * diffusion kurtosis imaging * substantia nigra * sriatum * thalamus * TNWT-61 * parkinson's disease * transgenic mice * animal model Subject RIV: BH - Optics, Masers, Lasers Impact factor: 5.964, year: 2016

  15. Impairments of thalamic resting-state functional connectivity in patients with chronic tinnitus

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jian [Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China); Chen, Yu-Chen [Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China); Center for Hearing and Deafness, University at Buffalo, State University of New York, Buffalo, NY (United States); Feng, Xu [Department of Otolaryngology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China); Yang, Ming; Liu, Bin; Qian, Cheng [Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China); Wang, Jian [Department of Physiology, Southeast University, Nanjing (China); School of Human Communication Disorders, Dalhousie University, Halifax, NS (Canada); Salvi, Richard [Center for Hearing and Deafness, University at Buffalo, State University of New York, Buffalo, NY (United States); Teng, Gao-Jun, E-mail: gjteng@vip.sina.com [Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China)

    2015-07-15

    Highlights: • Tinnitus patients have aberrant thalamic connectivity to many brain regions. • Decreased thalamic connectivity is linked with tinnitus characteristics. • Thalamocortical connectivity disturbances can reflect tinnitus-related networks. - Abstract: Purpose: The phantom sound of tinnitus is believed to arise from abnormal functional coupling between the thalamus and cerebral cortex. To explore this hypothesis, we used resting-state functional magnetic resonance imaging (fMRI) to compare the degree of thalamocortical functional connectivity in chronic tinnitus patients and controls. Materials and methods: Resting-state fMRI scans were obtained from 31 chronic tinnitus patients and 33 well-matched healthy controls. Thalamocortical functional connectivity was characterized using a seed-based whole-brain correlation method. The resulting thalamic functional connectivity measures were correlated with other clinical data. Results: We found decreased functional connectivity between the seed region in left thalamus and right middle temporal gyrus (MTG), right middle orbitofrontal cortex, left middle frontal gyrus, right precentral gyrus, and bilateral calcarine cortex. Decreased functional connectivity was detected between the seed in the right thalamus and the left superior temporal gyrus (STG), left amygdala, right superior frontal gyrus, left precentral gyrus, and left middle occipital gyrus. Tinnitus distress correlated negatively with thalamic functional connectivity in right MTG; tinnitus duration correlated negatively with thalamic functional connectivity in left STG. Increased functional connectivity between the bilateral thalamus and a set of regions were also observed. Conclusions: Chronic tinnitus patients have disrupted thalamocortical functional connectivity to selected brain regions which is associated with specific tinnitus characteristics. Resting-state thalamic functional connectivity disturbances may play an important role in

  16. [Functional analysis of the thalamocortical pathways in eye movements].

    Science.gov (United States)

    Kunimatsu, Jun; Tanaka, Masaki

    2011-08-01

    Although the roles of the thalamocortical pathways in somatic movements are well documented, their roles in eye movements have only recently been examined. The oculomotor-related areas in the frontal cortex receive inputs from the basal ganglia and the cerebellum via the thalamus. Consistent with this, neurons in the paralaminar part of the ventrolateral (VL), ventroanterior (VA), and mediodorsal (MD) nuclei and those in the intralaminar nuclei exhibit a variety of eye movement-related responses. To date, the thalamocortical pathways are known to play at least 2 roles in eye movements. First, they are involved in the generation of volitional, but not reactive, saccades. Thalamic neurons discharge during anti-saccades, which are known to be impaired in several neurological and psychiatric disorders, such as Parkinson's disease, attention deficit/hyperactivity disorder, and schizophrenia. In addition, neurons in the thalamus also exhibit a gradual increase in firing rate that predicts the timing of self-initiated saccades. Recent inactivation experiments have established the causal roles of these thalamic signals in the generation of volitional saccades. Second, the thalamocortical pathways transmit the efference copy signals for eye movements. During inactivation of the MD thalamus, which relays signals from the superior colliculus to the frontal eye field (FEF), the accuracy of the saccade is reduced in tasks requiring efference copy signals. In addition, inactivation of the same pathways reduces the predictive visual response associated with saccades in neurons in the FEF. Moreover the VL thalamus has been reported to play a role in monitoring smooth pursuit. While the functional analysis of thalamocortical pathways in eye movements is just a beginning, the anatomical data suggest their important roles. Analysis of eye movement control may shed light on the functions of the thalamocortical pathways in general, and may reveal the neural mechanisms of cerebro

  17. Finasteride Has Regionally Different Effects on Brain Oxidative Stress and Acetylcholinesterase Activity in Acute Thioacetamide-Induced Hepatic Encephalopathy in Rats.

    Directory of Open Access Journals (Sweden)

    Dušan Mladenović

    Full Text Available Finasteride (FIN inhibits neurosteroid synthesis and potentially improves the course of hepatic encephalopathy (HE. This study aimed to investigate the effects of FIN on brain oxidative stress and acetylcholinesterase (AchE activity in acute thioacetamide-induced HE in rats. Male Wistar rats were divided into groups: 1. control; 2. thioacetamide-treated group (TAA; 900 mg/kg; 3. finasteride-treated group (FIN; 150 mg/kg; 4. group treated with FIN and TAA (FIN+TAA. Daily doses of FIN (50 mg/kg and TAA (300 mg/kg were administered intraperitoneally during three days and in FIN+TAA group FIN was administered 2h before every dose of TAA. FIN pretreatment prevented TAA-induced rise in malondialdehyde level in the cortex due to restoration of catalase activity and increased expression of superoxide dismutase 1 (SOD1 and induced an increase in malondialdehyde level in the thalamus due to reduction of glutathione peroxidase (GPx and glutathione reductase (GR activity. Although FIN pretreatment did not affect malondialdehyde level in hippocampus and caudate nucleus, hippocampal SOD1 expression was higher (p<0.05 and GR activity lower in FIN+TAA vs. TAA group (p<0.05. GPx activity was lower in caudate nucleus in FIN+TAA vs. TAA group (p<0.01. FIN pretreatment prevented TAA-induced rise in AchE activity in the thalamus and caudate nucleus and AchE activity correlates inversely in the thalamus (p<0.05 and positively in caudate nucleus (p<0.01 with malondialdehyde level. FIN has regionally selective effects on oxidative stress and AchE activity in the brain in acute TAA-induced HE in rats. The prooxidant role of FIN in the thalamus may be causally linked with inhibition of AchE.

  18. [Computer tomography image of brain changes in an adult following resuscitation].

    Science.gov (United States)

    Kock, C; Helmke, K

    1983-12-01

    First description of a CT cerebral finding in an adult who had suffered cardiac arrest 14 days prior to CT and had been reanimated. Parts of the cerebral cortex, the thalamus and the brain stem ganglia appear moderately hyperdense; after injection of contrast medium there was a marked enhancement in these regions of the brain. The possible neuropathological correlate of this CT finding is discussed on the basis of relevant literature.

  19. Cell Proliferation in the Forebrain and Midbrain of the Adult Bullfrog, Rana catesbeiana

    OpenAIRE

    Simmons, Andrea Megela; Horowitz, Seth S.; Brown, Rebecca A.

    2007-01-01

    The distribution of proliferating cells in the midbrain, thalamus, and telencephalon of adult bullfrogs (Rana catesbeiana) was examined using immunohistochemistry for the thymidine analog 5-bromo-2′-deoxyuridine (BrdU) and DNA dot-blotting. At all time points examined (2 to 28 days post-injection), BrdU-labeled cells were located in ventricular zones at all levels of the neuraxis, but with relatively more label around the telencephalic ventricles. Labeled cells, some showing profiles indicati...

  20. Regional Abnormality of Grey Matter in Schizophrenia: Effect from the Illness or Treatment?

    Directory of Open Access Journals (Sweden)

    Ying Yue

    Full Text Available Both schizophrenia and antipsychotic treatment are known to modulate brain morphology. However, it is difficult to establish whether observed structural brain abnormalities are due to disease or the effects of treatment. The aim of this study was to investigate the effects of illness and antipsychotic treatment on brain structures in antipsychotic-naïve first-episode schizophrenia based on a longitudinal short-term design. Twenty antipsychotic-naïve subjects with first-episode schizophrenia and twenty-four age- and sex-matched healthy controls underwent 3T MRI scans. Voxel-based morphometry (VBM was used to examine the brain structural abnormality in patients compared to healthy controls. Nine patients were included in the follow-up examination after 8 weeks of treatment. Tensor-based morphometry (TBM was used to identify longitudinal brain structural changes. We observed significantly reduced grey matter volume in the right superior temporal gyrus in antipsychotic-naïve patients with schizophrenia compared with healthy controls. After 8 weeks of treatment, patients showed significantly increased grey matter volume primarily in the bilateral prefrontal cortex, insula, right thalamus, left superior occipital cortex and the bilateral cerebellum. In addition, a greater enlargement of the prefrontal cortex is associated with the improvement in negative symptoms, and a more enlarged thalamus is associated with greater improvement in positive symptoms. Our results suggest the following: (1 the abnormality in the right superior temporal gyrus is present in the early stages of schizophrenia, possibly representing the core region related to schizophrenia; and (2 atypical antipsychotics could modulate brain morphology involving the thalamus, cortical grey matter and cerebellum. In addition, examination of the prefrontal cortex and thalamus might facilitate an efficient response to atypical antipsychotics in terms of symptom improvement.

  1. The cranial MRI in severe cerebral palsy; A comparative study with clinical data

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Kazutaka; Itoh, Masahiro; Fueki, Noboru; Hirasawa, Kyoko; Suzuki, Noriko; Kurata, Kiyoko (Metropolitan Medical Center of the Severely Handicapped, Tokyo (Japan)); Sato, Junichi; Morimatsu, Yoshio; Yagishita, Akira

    1993-09-01

    The magnetic resonance examination was performed in 38 patients with severe cerebral palsy (CP; 15 males and 23 females) who had both motor delay (unable to move anywhere) and mental retardation (I.Q. or D.Q. below 30). Neuroimaging findings were compared with the CP type, etiology, and grade of understanding of language. Cranial magnetic resonance imagings (MRI) in CP were divided into five types. In type 1, nine predominantly showed cyst-liked ventricles and periventricular hyperintensity on T[sub 2]-weighted imaging (PVH) and only scarred basal ganglia and thalamus were visible. All suffered from neonatal asphyxia and the clinical type was rigospastic tetraplegia (RST). In type 2, eleven predominantly showed PVH and hyperintensity on T[sub 2]-weighted (HT2) in basal ganglia and thalamus. All suffered from neonatal asphyxia and the clinical type was RST or rigospastic diplegia. In type 3, five showed PVH and three had cortical atrophy. All suffered from neonatal asphyxia and the clinical type was spastic diplegia. In type 4, four predominantly showed HT2 in putamen and thalamus. Three had cortical atrophy. All suffered from neonatal asphyxia. The clinical type was athetotic CP (ATH). In type 5, nine predominantly showed HT2 in globus pallidus. Four had cortical atrophy and two had hippocampal atrophy. All suffered from neonatal jaundice and the clinical type was ATH. All patients who suffered from neonatal asphyxia and spastic CP had MRI in PVH. All patients who suffered from neonatal asphyxia and ATH showed HT2 in putamen and thalamus. Almost patients who suffered from neonatal jaundice and ATH showed HT2 in globus pallidus. With athetotic CP, cases with atrophy of the cerebral cortex and/or hippocampus were lower grade of understanding of language than no atrophy of both. The results of studies of MRI are in agreement with neuropathological findings. (author).

  2. Wernicke's Encephalopathy Complicating Hyperemesis during Pregnancy

    OpenAIRE

    Mohamed Adnane Berdai; Smael Labib; Mustapha Harandou

    2016-01-01

    Wernicke’s encephalopathy is caused by severe thiamine deficiency; it is mostly observed in alcoholic patients. We report the case of a 28-year-old woman, at 17 weeks of gestational age, with severe hyperemesis gravidarum. She presented with disturbance of consciousness, nystagmus, ophthalmoplegia, and ataxia. The resonance magnetic imagery showed bilaterally symmetrical hyperintensities of thalamus and periaqueductal area. The case was managed with very large doses of thiamine. The diagnosis...

  3. Advances in Therapeutic Options for Gait and Balance in Parkinson's Disease

    OpenAIRE

    Bohnen, Nicolaas I.; Albin, Roger L.; Müller, Martijn L.T.M; Chou, Kelvin

    2011-01-01

    There is a need to explore non-dopaminergic approaches to treating balance and gait problems in PD. There is emerging evidence on the role of cholinergic denervation of the PPN-thalamus system and falls in PD. Preliminary clinical trial data suggest that the subgroup of PD patients with frequent falls may be suitable candidates for future cholinergic augmentation clinical trials. Recent controlled clinical trials using methylphenidate have been unable to confirm earlier reports of improved ga...

  4. Responses of the Human Brain to Mild Dehydration and Rehydration Explored In Vivo by 1H-MR Imaging and Spectroscopy.

    Science.gov (United States)

    Biller, A; Reuter, M; Patenaude, B; Homola, G A; Breuer, F; Bendszus, M; Bartsch, A J

    2015-12-01

    As yet, there are no in vivo data on tissue water changes and associated morphometric changes involved in the osmo-adaptation of normal brains. Our aim was to evaluate osmoadaptive responses of the healthy human brain to osmotic challenges of de- and rehydration by serial measurements of brain volume, tissue fluid, and metabolites. Serial T1-weighted and (1)H-MR spectroscopy data were acquired in 15 healthy individuals at normohydration, on 12 hours of dehydration, and during 1 hour of oral rehydration. Osmotic challenges were monitored by serum measures, including osmolality and hematocrit. MR imaging data were analyzed by using FreeSurfer and LCModel. On dehydration, serum osmolality increased by 0.67% and brain tissue fluid decreased by 1.63%, on average. MR imaging morphometry demonstrated corresponding decreases of cortical thickness and volumes of the whole brain, cortex, white matter, and hypothalamus/thalamus. These changes reversed during rehydration. Continuous fluid ingestion of 1 L of water for 1 hour within the scanner lowered serum osmolality by 0.96% and increased brain tissue fluid by 0.43%, on average. Concomitantly, cortical thickness and volumes of the whole brain, cortex, white matter, and hypothalamus/thalamus increased. Changes in brain tissue fluid were related to volume changes of the whole brain, the white matter, and hypothalamus/thalamus. Only volume changes of the hypothalamus/thalamus significantly correlated with serum osmolality. This is the first study simultaneously evaluating changes in brain tissue fluid, metabolites, volume, and cortical thickness. Our results reflect cellular volume regulatory mechanisms at a macroscopic level and emphasize that it is essential to control for hydration levels in studies on brain morphometry and metabolism in order to avoid confounding the findings. © 2015 by American Journal of Neuroradiology.

  5. A distinct boundary between the higher brain's susceptibility to ischemia and the lower brain's resistance.

    Directory of Open Access Journals (Sweden)

    C Devin Brisson

    Full Text Available Higher brain regions are more susceptible to global ischemia than the brainstem, but is there a gradual increase in vulnerability in the caudal-rostral direction or is there a discrete boundary? We examined the interface between `higher` thalamus and the hypothalamus the using live brain slices where variation in blood flow is not a factor. Whole-cell current clamp recording of 18 thalamic neurons in response to 10 min O2/glucose deprivation (OGD revealed a rapid anoxic depolarization (AD from which thalamic neurons do not recover. Newly acquired neurons could not be patched following AD, confirming significant regional thalamic injury. Coinciding with AD, light transmittance (LT imaging during whole-cell recording showed an elevated LT front that initiated in midline thalamus and that propagated into adjacent hypothalamus. However, hypothalamic neurons patched in paraventricular nucleus (PVN, n= 8 magnocellular and 12 parvocellular neurons and suprachiasmatic nucleus (SCN, n= 18 only slowly depolarized as AD passed through these regions. And with return to control aCSF, hypothalamic neurons repolarized and recovered their input resistance and action potential amplitude. Moreover, newly acquired hypothalamic neurons could be readily patched following exposure to OGD, with resting parameters similar to neurons not previously exposed to OGD. Thalamic susceptibility and hypothalamic resilience were also observed following ouabain exposure which blocks the Na(+/K(+ pump, evoking depolarization similar to OGD in all neuronal types tested. Finally, brief exposure to elevated [K(+]o caused spreading depression (SD, a milder, AD-like event only in thalamic neurons so SD generation is regionally correlated with strong AD. Therefore the thalamus-hypothalamus interface represents a discrete boundary where neuronal vulnerability to ischemia is high in thalamus (like more rostral neocortex, striatum, hippocampus. In contrast hypothalamic neurons are

  6. The psiconeural relation in stress or from neurons to social cognition: an empirical review

    OpenAIRE

    Campos Roldán, Manuel; Facultad de Psicología de la UAM

    2014-01-01

    It reviews the brain activity, facts perception-appraisal, social context and neural mechanisms related in stress processes. In this paper, that sequence defines the psychoneural relation, situated in the prefrontal cortex and thalamus dorsomedial-amygdala circuit. El trabajo revisa los mecanismos neurales que hacen posible la relación entre actividad cerebral, percepción-evaluación de acontecimientos y contexto social en el desenlace del estrés. Sostiene la tesis de que dicha secuencia cr...

  7. Remote neuroimmune signaling: a long-range mechanism of nociceptive network plasticity.

    Science.gov (United States)

    Saab, Carl Y; Hains, Bryan C

    2009-02-01

    Chronic pain secondary to neuronal injury is actively and continuously modulated at multiple locations along the sensory neuraxis. Here, we describe how nociceptive neurons of the spinal cord and thalamus process and communicate nociceptive information in terms of precisely calibrated firing patterns. We then discuss how several cell types with immunogenic properties (e.g. blood cells and glia) cause system-wide interference in nociceptive processing through novel signaling schema, thus contributing to nociceptive network plasticity and chronic pain.

  8. Altered cortico-striatal-thalamic connectivity in relation to spatial working memory capacity in children with ADHD

    Directory of Open Access Journals (Sweden)

    Kathryn L. Mills

    2012-01-01

    Full Text Available Introduction: Attention deficit hyperactivity disorder (ADHD captures a heterogeneous group of children, who are characterized by a range of cognitive and behavioral symptoms. Previous resting state functional connectivity (rs-fcMRI studies have sought to understand the neural correlates of ADHD by comparing connectivity measurements between those with and without the disorder, focusing primarily on cortical-striatal circuits mediated by the thalamus. To integrate the multiple phenotypic features associated with ADHD and help resolve its heterogeneity, it is helpful to determine how specific circuits relate to unique cognitive domains of the ADHD syndrome. Spatial working memory has been proposed as a key mechanism in the pathophysiology of ADHD.Methods: We correlated the rs-fcMRI of five thalamic regions of interest with spatial span working memory scores in a sample of 67 children aged 7-11 years (ADHD and typically developing children; TDC. In an independent dataset, we then examined group differences in thalamo-striatal functional connectivity between 70 ADHD and 89 TDC (7-11 years from the ADHD-200 dataset. Thalamic regions of interest were created based on previous methods that utilize known thalamo-cortical loops and rs-fcMRI to identify functional boundaries in the thalamus.Results/Conclusions: Using these thalamic regions, we found atypical rs-fcMRI between specific thalamic groupings with the basal ganglia. To identify the thalamic connections that relate to spatial working memory in ADHD, only connections identified in both the correlational and comparative analyses were considered. Multiple connections between the thalamus and basal ganglia, particularly between medial and anterior dorsal thalamus and the putamen, were related to spatial working memory and also altered in ADHD. These thalamo-striatal disruptions may be one of multiple atypical neural and cognitive mechanisms that relate to the ADHD clinical phenotype.

  9. Human pallidothalamic and cerebellothalamic tracts: anatomical basis for functional stereotactic neurosurgery

    Science.gov (United States)

    Gallay, Marc N.; Jeanmonod, Daniel; Liu, Jian

    2008-01-01

    Anatomical knowledge of the structures to be targeted and of the circuitry involved is crucial in stereotactic functional neurosurgery. The present study was undertaken in the context of surgical treatment of motor disorders such as essential tremor (ET) and Parkinson’s disease (PD) to precisely determine the course and three-dimensional stereotactic localisation of the cerebellothalamic and pallidothalamic tracts in the human brain. The course of the fibre tracts to the thalamus was traced in the subthalamic region using multiple staining procedures and their entrance into the thalamus determined according to our atlas of the human thalamus and basal ganglia [Morel (2007) Stereotactic atlas of the human thalamus and basal ganglia. Informa Healthcare Inc., New York]. Stereotactic three-dimensional coordinates were determined by sectioning thalamic and basal ganglia blocks parallel to stereotactic planes and, in two cases, by correlation with magnetic resonance images (MRI) from the same brains prior to sectioning. The major contributions of this study are to provide: (1) evidence that the bulks of the cerebellothalamic and pallidothalamic tracts are clearly separated up to their thalamic entrance, (2) stereotactic maps of the two tracts in the subthalamic region, (3) the possibility to discriminate between different subthalamic fibre tracts on the basis of immunohistochemical stainings, (4) correlations of histologically identified fibre tracts with high-resolution MRI, and (5) evaluation of the interindividual variability of the fibre systems in the subthalamic region. This study should provide an important basis for accurate stereotactic neurosurgical targeting of the subthalamic region in motor disorders such as PD and ET. PMID:18193279

  10. Supraspinal gene transfer by intrathecal adeno-associated virus serotype 5

    OpenAIRE

    Schuster, Daniel J.; Belur, Lalitha R.; Riedl, Maureen S.; Schnell, Stephen A.; Podetz-Pedersen, Kelly M; Kitto, Kelley F.; R. Scott McIvor; Lucy eVulchanova; Fairbanks, Carolyn A.

    2014-01-01

    We report the pattern of transgene expression across brain regions after intrathecal delivery of adeno-associated virus serotype 5 (AAV5). Labeling in hindbrain appeared to be primarily neuronal, and was detected in sensory nuclei of medulla, pontine nuclei, and all layers of cerebellar cortex. Expression in midbrain was minimal, and generally limited to isolated neurons and astrocytes in the cerebral peduncles. GFP immunoreactivity (-ir) in thalamus was most prominent in medial geniculate nu...

  11. Wnt3 and Wnt3a are required for induction of the mid-diencephalic organizer in the caudal forebrain

    Directory of Open Access Journals (Sweden)

    Mattes Benjamin

    2012-04-01

    Full Text Available Abstract Background A fundamental requirement for development of diverse brain regions is the function of local organizers at morphological boundaries. These organizers are restricted groups of cells that secrete signaling molecules, which in turn regulate the fate of the adjacent neural tissue. The thalamus is located in the caudal diencephalon and is the central relay station between the sense organs and higher brain areas. The mid-diencephalic organizer (MDO orchestrates the development of the thalamus by releasing secreted signaling molecules such as Shh. Results Here we show that canonical Wnt signaling in the caudal forebrain is required for the formation of the Shh-secreting MD organizer in zebrafish. Wnt signaling induces the MDO in a narrow time window of 4 hours - between 10 and 14 hours post fertilization. Loss of Wnt3 and Wnt3a prevents induction of the MDO, a phenotype also observed upon blockage of canonical Wnt signaling per se. Pharmaceutical activation of the canonical Wnt pathways in Wnt3/Wnt3a compound morphant embryos is able to restore the lack of the MDO. After blockage of Wnt signaling or knock-down of Wnt3/Wnt3a we find an increase of apoptotic cells specifically within the organizer primordium. Consistently, blockage of apoptosis restores the thalamus organizer MDO in Wnt deficient embryos. Conclusion We have identified canonical Wnt signaling as a novel pathway, that is required for proper formation of the MDO and consequently for the development of the major relay station of the brain - the thalamus. We propose that Wnt ligands are necessary to maintain the primordial tissue of the organizer during somitogenesis by suppressing Tp53-mediated apoptosis.

  12. Case report

    African Journals Online (AJOL)

    abp

    5 sept. 2013 ... service de neurologie pour déficit moteur brutal de l'hémicorps droit avec aphasie; le bilan clinique avait conclu à un AVC et la tomodensitométrie cérébrale avait objectivé une hypodensité du thalamus et du bras postérieur de la capsule interne gauches. Les explorations biologiques avaient objectivé par ...

  13. Subarachnoid hemorrhage due to ruptured intracranial aneurysm following posterior reversible encephalopathy syndrome

    OpenAIRE

    Takamasa Nanba; Hiroshi Kashimura; Hiroaki Saura; Masaru Takeda

    2016-01-01

    Although posterior reversible encephalopathy syndrome (PRES) is rarely associated with subarachnoid hemorrhage, to our knowledge, rupture of a concomitant cerebral aneurysm following PRES has not been reported. We describe a patient with atypical PRES involving the brainstem, thalamus, and periventricular white matter without cortical or subcortical edema of the parietooccipital lobe on magnetic resonance imaging, with rupture of a concomitant cerebral aneurysm. Preexisting extremely high blo...

  14. Decreased thalamic glutamate level in unmedicated adult obsessive-compulsive disorder patients detected by proton magnetic resonance spectroscopy.

    Science.gov (United States)

    Zhu, Yajing; Fan, Qing; Han, Xu; Zhang, Haiyin; Chen, Jue; Wang, Zhen; Zhang, Zongfeng; Tan, Ling; Xiao, Zeping; Tong, Shanbao; Maletic-Savatic, Mirjana; Li, Yao

    2015-06-01

    Previous neuroimaging studies implied that the dysfunction of cortico-striato-thalamo-cortical (CSTC) circuit served as the neural basis for the pathophysiology of obsessive-compulsive disorder (OCD). The imbalances in neuronal metabolite and neurotransmitter within CSTC circuit have been shown as the leading reasons of the OCD onset. The aim of this study is to investigate the metabolic alterations, especially the glutamatergic signal dysfunction within CSTC circuit, and the relationships between neural metabolites and the symptom severity of OCD patients. Single voxel magnetic resonance spectroscopy (MRS) was conducted in medial prefrontal cortex (mPFC) and bilateral thalamus areas for thirteen unmedicated adult OCD patients with age-, gender-, and education-matched healthy controls. Quantification and multivariate analysis were performed to identify vital metabolic biomarkers for patients and healthy controls group differentiation. Moreover, we performed Spearman׳s rank correlation analysis for OCD patients to examine the relationship between the metabolite concentration level and OCD symptomatology. Patients with OCD showed significantly decreased glutamate level in mPFC (p=0.021) and right thalamus (p=0.039), and significantly increased choline compounds in left thalamus (p=0.044).The glutamate in right thalamus was shown as the most important metabolite for group separation from multivariate analysis (Q(2)=0.134) and was significantly correlated with the patients׳ compulsion scores (Spearman r=-0.674, p=0.016). Limited sample size, the use of creatine and phosphocreatine (Cr) ratios rather than absolute concentrations and unresolved glutamine (Gln) are limitations of the present study. Our study results consolidated the hypothesis about glutamatergic signaling dysfunction in OCD. To our knowledge, it is the first finding about a reduced thalamic glutamate level in adult unmedicated OCD patients. The dysregulation of glutamate serves as a potential target

  15. Symptomatic palatal tremor is not limited to the activity of guillain-mollaret triangle: A functional magnetic resonance imaging case study

    OpenAIRE

    Balaban, Hatice; Kayım Yıldız, Özlem; Öztoprak, İbrahim; Bolayır, Ertuğrul; Topaktaş, Suat

    2012-01-01

    Abstract A 57-year-old man was admitted to our clinic because of speech and swallowing disorder for six months. Palatal tremor and left upper extremity myorhythmia appeared on examination. Magnetic resonance imaging showed hypertrophic olivary degeneration, dentate pathology, Wallerian degeneration, and left parietal cystic encephalomalacia. Functional magnetic resonance imaging study of the brain showed prominent activation on the bilateral globus pallidus and thalamus. We suggest that invol...

  16. A theory about a role of the hyper direct pathway in pattern expression by the basal ganglia.

    Science.gov (United States)

    Jourdan, Ivan; Barttfeld, Pablo; Zanutto, B Silvano

    2010-01-01

    The Basal Ganglia (BG) are a group of nuclei, in the brain of mammalians and other vertebrates, strongly connected with the cerebral cortex, thalamus and other brain areas. The BG are associated with several brain functions including learning and motor control. When there is cortical activation, there is a strong synchronization between BG and cortex, i.e. when a given task is being executed or in the case of Parkinson disease[1], [2]. If we consider the internal segment of the Globus Pallidus (GPi) there is synchronism between GPi-cortex at frequencies as low as 3Hz to as high as 85Hz [1], [3]. In the other hand, in a delta sleep or in an anesthetized case, a very low frequency correlation is observed (1-10 Hz), but no high frequency correlation between GPi-cortex [1], [2], [3]. It is unknown why this decorrelation happens. But It is agreement that when there is no pattern to select, like in delta sleep or with an anesthetized model, the BG network would maintain the GPi and cortex decorrelated at high frequencies. Many thalamus-BG and thalamus-BG-cortex loops are modulators of the BG activity. Particularly there exists an anatomic thalamus-BG loop, formed by GPi, intralaminar thalamic nuclei (IL) and Subthalamic Nucleus (STN) [4]. Using a computational model, based on an "Integrate and Fire" neural network, we analyzed the IL nucleus as a modulator of the so-called hyper direct pathway. Our results show that, in an anesthetic case, this thalamic path could be relevant to allow a high frequency decorrelated state between the GPi and cortex.

  17. The thalamocortical vestibular system in animals and humans

    OpenAIRE

    LOPEZ, Christophe; Blanke, Olaf

    2011-01-01

    The vestibular system provides the brain with sensory signals about three-dimensional head rotations and translations. These signals are important for postural and oculomotor control, as well as for spatial and bodily perception and cognition, and they are subtended by pathways running from the vestibular nuclei to the thalamus, cerebellum and the "vestibular cortex." The present review summarizes current knowledge on the anatomy of the thalamocortical vestibular system and discusses data fro...

  18. [Anatomy and physiology of the vestibular system: review of the literature].

    Science.gov (United States)

    Sakka, L; Vitte, E

    2004-10-01

    The vestibular system is a complex system involving not only posterior labyrinth but also central structures such as cerebellum, striatum, thalamus, frontal and prefrontal cortex to assure balance, movements and walking. Information reaching the vestibular complex are not purely vestibular but also from visual, somatosensory and cerebellar origins. The equilibrium is also a complex physiological function needing concordance of vestibular, visual and somatosensory information or either central compensation after an injury but also an integrity of the central nervous system.

  19. Quantitative T2* magnetic resonance imaging for evaluation of iron deposition in the brain of β-thalassemia patients.

    Science.gov (United States)

    Akhlaghpoor, S; Ghahari, A; Morteza, A; Khalilzadeh, O; Shakourirad, A; Alinaghizadeh, M R

    2012-09-01

    Iron overload is a common clinical problem in patients with β-thalassemia major. The purpose of this study was to assess the presence of excess iron in certain areas of the brain (thalamus, midbrain, adenohypophysis and basal ganglia) in patients with β-thalassemia major and evaluate the association with serum ferritin and liver iron content. A cross-sectional study on 53 patients with β-thalassemia major and 40 healthy controls was carried out. All patients and healthy controls underwent magnetic resonance imaging (MRI) examinations of the brain and liver. Multiecho fast gradient echo sequence was used and T2* values were calculated based on the Brompton protocol. Correlations between T2* values in the brain with T2* values in the liver as well as serum ferritin levels were investigated. There were no significant differences between patients and healthy controls with respect to age and sex. Patients had significantly lower T2* values in basal ganglia (striatum), thalamus and adenohypophysis compared to controls while there were no differences in the midbrain (red nucleus). There were no significant correlations between liver T2* values or serum ferritin with T2* values of basal ganglia (striatum), thalamus and adenohypophysis in patients or healthy controls. There were no significant correlations between T2* values of adenohypophysis and thalamus or basal ganglia (striatum) while these variables were significantly correlated in healthy controls. Serum ferritin and liver iron content may not be good indicators of brain iron deposition in patients with β thalassemia major. Nevertheless, the quantitative T2* MRI technique is useful for evaluation of brain iron overload in β thalassemia major patients.

  20. How the Brain Works

    Science.gov (United States)

    1994-02-01

    olfactory lobe in amphibia and fits like a cap over the thalamus. The inner part, the basal ganglia (caudate nucleus, putamen, globus pallidus. and some...afferent To the receiving neuron, the synapse is afferent. amphibia A class of vertebrates, intermediate between fishes and reptiles. amygdala Nucleus...Posterior lobe of cerebral hemisphere. olfaction Sense of smell. olfactory lobe The internet for smell in amphibia ; becomes the olfactory bulb and the

  1. Follow-up findings in regional cerebral blood flow (r-CBF)-SPECT in a case of idiopathic childhood hemidystonia. Functional neuroimaging and pathophysiological implications

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, A.; Aderbauer, J.; Segerer, H. [St. Hedwig Hospital, Regensburg (Germany). Dept. of Pediatrics; Marienhagen, J.; Bock, E.; Eilles, C. [Univ. Hospital, Regensburg (Germany). Dept. of Nuclear Medicine

    1999-05-01

    A 9 1/2-year-old girl suffered from intermitting tremor and jitteriness of her left hand and oral muscles every 4 to 6 weeks with long lasting episodes. Clinically myoclonias and dystonic positioning of the left arm, hand and facial muscles were seen. No evidence of trauma, infection or inborn errors of metabolism was found. Successful therapy with carbamazepine was initiated while L-DOPA failed. An ictal 99m-Tc-HMPAO-SPECT showed severe asymmetry with focal hyperperfusion of the contralateral right thalamus and basal ganglia as well as of the bifrontal cortex, whereas no anatomical lesions were found by MRI. In contrast, an interictally performed 99m-Tc-HMPAO SPECT showed hypoperfusion or the right thalamus and normalisation of the frontal perfusion under medical treatment. These 99m-Tc-HMPAO-SPECT findings may provide new insights into the localisation and pathophysiological pathways of idiopathic childhood dystonia. (orig.) [Deutsch] Ein 9 1/2jaehriges Maedchen litt an rezidivierenden, langdauernden Schueben von Tremor und Zittern der linken Hand und der perioralen Muskulatur links. Klinisch fanden sich eine dystone Haltung des linken Armes und unerschoepfliche Myoklonien des Armes, der Hand und der Gesichtsmuskulatur links. Trauma, Infektion oder ein Stoffwechseldefekt als Ursache lagen nicht vor. Ein Therapieversuch mit L-DOPA war erfolglos. Unter Gabe von Carbamazepin wurde Beschwerdefreiheit bleibend erreicht. Ein iktuales 99m-Tc-HMPAO-SPECT zeigte eine fokale Hyperperfusion des rechtsseitigen Thalamus und der Basalganglien, sowie des bifrontalen Kortex. Ein interiktuales 99m-Tc-HMPAOSPECT ergab dann eine deutliche Hypoperfusion des rechtseitigen Thalamus bei normalisierter Perfusion des bifrontalen Kortex. Eine kranielle Magnetresonanztomographie (MRI) ergab einen unauffaelligen Befund. Der Vergleich der iktualen und interiktualen Perfusionsverhaeltnisse weist auf neue pathophysiologische Zusammenhaenge bei idiopathischer kindlicher Dystonie hin. (orig.)

  2. Alcohol affects brain functional connectivity and its coupling with behavior: greater effects in male heavy drinkers.

    Science.gov (United States)

    Shokri-Kojori, E; Tomasi, D; Wiers, C E; Wang, G-J; Volkow, N D

    2017-08-01

    Acute and chronic alcohol exposure significantly affect behavior but the underlying neurobiological mechanisms are still poorly understood. Here, we used functional connectivity density (FCD) mapping to study alcohol-related changes in resting brain activity and their association with behavior. Heavy drinkers (HD, N=16, 16 males) and normal controls (NM, N=24, 14 males) were tested after placebo and after acute alcohol administration. Group comparisons showed that NM had higher FCD in visual and prefrontal cortices, default mode network regions and thalamus, while HD had higher FCD in cerebellum. Acute alcohol significantly increased FCD within the thalamus, impaired cognitive and motor functions, and affected self-reports of mood/drug effects in both groups. Partial least squares regression showed that alcohol-induced changes in mood/drug effects were associated with changes in thalamic FCD in both groups. Disruptions in motor function were associated with increases in cerebellar FCD in NM and thalamus FCD in HD. Alcohol-induced declines in cognitive performance were associated with connectivity increases in visual cortex and thalamus in NM, but in HD, increases in precuneus FCD were associated with improved cognitive performance. Acute alcohol reduced 'neurocognitive coupling', the association between behavioral performance and FCD (indexing brain activity), an effect that was accentuated in HD compared with NM. Findings suggest that reduced cortical connectivity in HD contribute to decline in cognitive abilities associated with heavy alcohol consumption, whereas increased cerebellar connectivity in HD may have compensatory effects on behavioral performance. The results reveal how drinking history alters the association between brain FCD and individual differences in behavioral performance.

  3. Acute necrotising encephalopathy of childhood after exanthema subitum outside Japan or Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Porto, L.; Lanferman, H.; Moeller-Hartmann, W.; Jacobi, G.; Zanella, F. [Inst. fuer Neuroradiologie, Klinikum der Johann Wolfgang Goethe-Univ., Frankfurt am Main (Germany)

    1999-10-01

    Acute necrotising encephalopathy of childhood (ANE) is an uncommon disease which predominantly affects infants and young children living in Japan and Taiwan. A multifocal encephalopathy with symmetrical lesions in the thalamus, tegmentum of the brain stem, cerebral periventricular white matter and cerebellar medulla is characteristic. We present the imaging features in a 4-year-old Japanese boy who had been living in Germany for 2{sup 1}/{sub 2} years before presentation. (orig.)

  4. Differential regional gray matter volumes in patients with on-line game addiction and professional gamers.

    Science.gov (United States)

    Han, Doug Hyun; Lyoo, In Kyoon; Renshaw, Perry F

    2012-04-01

    Patients with on-line game addiction (POGA) and professional video game players play video games for extended periods of time, but experience very different consequences for their on-line game play. Brain regions consisting of anterior cingulate, thalamus and occpito-temporal areas may increase the likelihood of becoming a pro-gamer or POGA. Twenty POGA, seventeen pro-gamers, and eighteen healthy comparison subjects (HC) were recruited. All magnetic resonance imaging (MRI) was performed on a 1.5 Tesla Espree MRI scanner (SIEMENS, Erlangen, Germany). Voxel-wise comparisons of gray matter volume were performed between the groups using the two-sample t-test with statistical parametric mapping (SPM5). Compared to HC, the POGA group showed increased impulsiveness and perseverative errors, and volume in left thalamus gray matter, but decreased gray matter volume in both inferior temporal gyri, right middle occipital gyrus, and left inferior occipital gyrus, compared with HC. Pro-gamers showed increased gray matter volume in left cingulate gyrus, but decreased gray matter volume in left middle occipital gyrus and right inferior temporal gyrus compared with HC. Additionally, the pro-gamer group showed increased gray matter volume in left cingulate gyrus and decreased left thalamus gray matter volume compared with the POGA group. The current study suggests that increased gray matter volumes of the left cingulate gyrus in pro-gamers and of the left thalamus in POGA may contribute to the different clinical characteristics of pro-gamers and POGA. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. AAV-Mediated Gene Delivery in a Feline Model of Sandhoff Disease Corrects Lysosomal Storage in the Central Nervous System

    Directory of Open Access Journals (Sweden)

    Hannah E. Rockwell

    2015-04-01

    Full Text Available Sandhoff disease (SD is an autosomal recessive neurodegenerative disease caused by a mutation in the gene for the β-subunit of β-N-acetylhexosaminidase (Hex, resulting in the inability to catabolize ganglioside GM2 within the lysosomes. SD presents with an accumulation of GM2 and its asialo derivative GA2, primarily in the central nervous system. Myelin-enriched glycolipids, cerebrosides and sulfatides, are also decreased in SD corresponding with dysmyelination. At present, no treatment exists for SD. Previous studies have shown the therapeutic benefit of adeno-associated virus (AAV vector-mediated gene therapy in the treatment of SD in murine and feline models. In this study, we treated presymptomatic SD cats with AAVrh8 vectors expressing feline Hex in the thalamus combined with intracerebroventricular (Thal/ICV injections. Treated animals showed clearly improved neurologic function and quality of life, manifested in part by prevention or attenuation of whole-body tremors characteristic of untreated animals. Hex activity was significantly elevated, whereas storage of GM2 and GA2 was significantly decreased in tissue samples taken from the cortex, cerebellum, thalamus, and cervical spinal cord. Treatment also increased levels of myelin-enriched cerebrosides and sulfatides in the cortex and thalamus. This study demonstrates the therapeutic potential of AAV for feline SD and suggests a similar potential for human SD patients.

  6. Disconnection of the ascending arousal system in traumatic coma.

    Science.gov (United States)

    Edlow, Brian L; Haynes, Robin L; Takahashi, Emi; Klein, Joshua P; Cummings, Peter; Benner, Thomas; Greer, David M; Greenberg, Steven M; Wu, Ona; Kinney, Hannah C; Folkerth, Rebecca D

    2013-06-01

    Traumatic coma is associated with disruption of axonal pathways throughout the brain, but the specific pathways involved in humans are incompletely understood. In this study, we used high angular resolution diffusion imaging to map the connectivity of axonal pathways that mediate the 2 critical components of consciousness-arousal and awareness-in the postmortem brain of a 62-year-old woman with acute traumatic coma and in 2 control brains. High angular resolution diffusion imaging tractography guided tissue sampling in the neuropathologic analysis. High angular resolution diffusion imaging tractography demonstrated complete disruption of white matter pathways connecting brainstem arousal nuclei to the basal forebrain and thalamic intralaminar and reticular nuclei. In contrast, hemispheric arousal pathways connecting the thalamus and basal forebrain to the cerebral cortex were only partially disrupted, as were the cortical "awareness pathways." Neuropathologic examination, which used β-amyloid precursor protein and fractin immunomarkers, revealed axonal injury in the white matter of the brainstem and cerebral hemispheres that corresponded to sites of high angular resolution diffusion imaging tract disruption. Axonal injury was also present within the gray matter of the hypothalamus, thalamus, basal forebrain, and cerebral cortex. We propose that traumatic coma may be a subcortical disconnection syndrome related to the disconnection of specific brainstem arousal nuclei from the thalamus and basal forebrain.

  7. Detection and quantification of remote microglial activation in rodent models of focal ischaemia using the TSPO radioligand CLINDE

    Energy Technology Data Exchange (ETDEWEB)

    Arlicot, Nicolas [Universite Francois Rabelais de Tours, CHRU de Tours (France). UMR Inserm U 930, CNRS ERL 3106; UFR Sciences Pharmaceutiques, Laboratoire de Biophysique, Tours (France); Petit, Edwige; Toutain, Jerome; Divoux, Didier; Roussel, Simon; Bernaudin, Myriam [Universite de Caen Basse-Normandie, Universite Paris-Descartes, CNRS, CEA CYCERON, Caen (France). Equipe CERVOxy ' ' Hypoxie et Physiopathologie cerebrovasculaire' ' , UMR 6232 CI-NAPS; Katsifis, Andrew [ANSTO, Radiopharmaceuticals Research Institute, Menai (Australia); Bodard, Sylvie; Guilloteau, Denis; Chalon, Sylvie [Universite Francois Rabelais de Tours, CHRU de Tours (France). UMR Inserm U 930, CNRS ERL 3106

    2010-12-15

    Neuroinflammation is involved in stroke pathophysiology and might be imaged using radioligands targeting the 18 kDa translocator protein (TSPO). We studied microglial reaction in brain areas remote from the primary lesion site in two rodent models of focal cerebral ischaemia (permanent or transient) using [{sup 125}I]-CLINDE, a promising TSPO single photon emission computed tomography radioligand. In a mouse model of permanent middle cerebral artery occlusion (MCAO), ex vivo autoradiographic studies demonstrated, besides in the ischaemic territory, accumulation of [{sup 125}I]-CLINDE in the ipsilateral thalamus with a binding that progressed up to 3 weeks after MCAO. [{sup 125}I]-CLINDE binding markedly decreased in animals pre-injected with either unlabelled CLINDE or PK11195, while no change was observed with flumazenil pre-treatment, demonstrating TSPO specificity. In rats subjected to transient MCAO, [{sup 125}I]-CLINDE binding in the ipsilateral thalamus and substantia nigra pars reticulata (SNr) was significantly higher than that in contralateral tissue. Moreover, [{sup 125}I]-CLINDE binding in the thalamus and SNr was quantitatively correlated to the ischaemic volume assessed by MRI in the cortex and striatum, respectively. Clinical consequences of secondary neuronal degeneration in stroke might be better treated thanks to the discrimination of neuronal processes using in vivo molecular imaging and potent TSPO radioligands like CLINDE to guide therapeutic interventions. (orig.)

  8. [{sup 11}C]SMe-ADAM, an imaging agent for the brain serotonin transporter: synthesis, pharmacological characterization and microPET studies in rats

    Energy Technology Data Exchange (ETDEWEB)

    Zessin, Joerg [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany)]. E-mail: j.zessin@fz-rossendorf.de; Deuther-Conrad, Winnie [Institut fuer Interdisziplinaere Isotopenforschung, 04318 Leipzig (Germany); Kretzschmar, Marion [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Wuest, Frank [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Pawelke, Beate [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Brust, Peter [Institut fuer Interdisziplinaere Isotopenforschung, 04318 Leipzig (Germany); Steinbach, Joerg [Institut fuer Interdisziplinaere Isotopenforschung, 04318 Leipzig (Germany); Bergmann, Ralf [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany)

    2006-01-15

    N,N-Dimethyl-2-(2-amino-4-methylthiophenylthio)benzylamine (S Me-Adam, 1) is a highly potent and selective inhibitor of the serotonin transporter (SPERT). This compound was labeled with carbon-11 by methylation of the S-desmethyl precursor 10 with [{sup 11}C]methyl iodide to obtain the potential positron emission tomography (PET) radioligand [{sup 11}C]S Me-Adam. The radiochemical yield was 27{+-}5%, and the specific radioactivity was 26-40 GBq/{mu}mol at the end of synthesis. Ex vivo and in vivo biodistribution experiments in rats demonstrated a rapid accumulation of the radiotracer in brain regions known to be rich in SPERT, such as the thalamus/hypothalamus region (3.59{+-}0.41%ID/g at 5 min after injection). The specific uptake reached a thalamus to cerebellum ratio of 6.74{+-}0.95 at 60 min postinjection. The [{sup 11}C]SMe-ADAM uptake in the thalamus was significantly decreased by pretreatment with fluoxetine to 38{+-}11% of the control value. Furthermore, no metabolites of [{sup 11}C]SMe-ADAM could be detected in the SERT-rich regions of the rat brain. It is concluded that [{sup 11}C]SMe-ADAM may be a suitable PET ligand for SERT imaging in the living brain.

  9. Signal intensity change on unenhanced T1-weighted images in dentate nucleus and globus pallidus after multiple administrations of gadoxetate disodium: an intraindividual comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Giorgio; Minotti, Marta; De Piano, Francesca [Universita degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan (Italy); Preda, Lorenzo [Universita degli Studi di Pavia, Department of Clinical-Surgical Diagnostic and Pediatric Sciences, Pavia (Italy); National Center of Oncological Hadrontherapy (CNAO Foundation), Division of Radiology, Pavia (Italy); Cocorocchio, Emilia; Ferrucci, Pier Francesco [European Institute of Oncology, Melanoma and Sarcoma Medical Oncology Division, Milan (Italy); Raimondi, Sara [European Institute of Oncology, Division of Epidemiology and Biostatistics, Milan (Italy); Giannitto, Caterina; Petralia, Giuseppe [European Institute of Oncology, Division of Radiology, Milan (Italy); Bellomi, Massimo [European Institute of Oncology, Division of Radiology, Milan (Italy); Universita degli Studi di Milano, Oncology and Haematology/Oncology Department, Milan (Italy)

    2017-10-15

    To investigate whether there is an increased signal intensity (SI) of dentate nucleus (DN) and globus pallidus (GP) on unenhanced T1-weighted magnetic resonance imaging (MRI), in patients who had undergone multiple administrations of gadoxetate disodium. We retrospectively included stage III melanoma patients, who had been previously enrolled in a trial of adjuvant therapy and who had undergone whole-body contrast-enhanced MRIs with gadoxetate disodium every three months for their follow-up. The SI ratios of DN-to-pons and GP-to-thalamus on unenhanced T1-weighted images were calculated. The difference in SI ratios between the first and the last MRI examinations was assessed and a linear mixed model was performed to detect how SI ratios varied with the number of administrations. Eighteen patients were included in our study. The number of gadoxetate disodium administrations ranged from 2 to 18. Paired t-test did not show any significant difference in DN-to-pons (p=0.21) and GP-to-thalamus (p=0.09) SI ratios by the end of the study. DN-to-pons SI ratio and GP-to-thalamus SI ratio did not significantly increase with increasing the number of administrations (p=0.14 and p=0.06, respectively). Multiple administrations of gadoxetate disodium are not associated with increased SI in DN and GP in the brain. (orig.)

  10. Abnormal subcortical nuclei shapes in patients with type 2 diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ji; Wang, Xiaoyang; Li, Hui; Yang, Yanqiu; Lu, Jingjing; Chen, Ziqian [Fuzhou General Hospital, Department of Medical Imaging, Fuzhou, Fujian (China); Zhang, Junxiang [Bengbu Medical College, Department of Medical Imaging, Bengbu, Anhui (China); Liu, Xuebing [Fuzhou General Hospital, Department of Medical Imaging, Fuzhou, Fujian (China); The Second Affiliated Hospital of Nanjing Medical University, Department of Medical Imaging, Nanjing, Jiangsu (China); Xu, Xiangjin [Fuzhou General Hospital, Department of Endocrinology, Fuzhou, Fujian (China); Cao, Bo [The Second Affiliated Hospital of Nanjing Medical University, Department of Medical Imaging, Nanjing, Jiangsu (China)

    2017-10-15

    Type 2 diabetes mellitus (T2DM) increases the risk of brain atrophy and dementia. We aimed to elucidate deep grey matter (GM) structural abnormalities and their relationships with T2DM cognitive deficits by combining region of interest (ROI)-based volumetry, voxel-based morphometry (VBM) and shape analysis. We recruited 23 T2DM patients and 24 age-matched healthy controls to undergo T1-weighted structural MRI scanning. Images were analysed using the three aforementioned methods to obtain deep GM structural shapes and volumes. Biochemical and cognitive assessments were made and were correlated with the resulting metrics. Shape analysis revealed that T2DM is associated with focal atrophy in the bilateral caudate head and dorso-medial part of the thalamus. ROI-based volumetry only detected thalamic volume reduction in T2DM when compared to the controls. No significant between-group differences were found by VBM. Furthermore, a worse performance of cognitive processing speed correlated with more severe GM atrophy in the bilateral dorso-medial part of the thalamus. Also, the GM volume in the bilateral dorso-medial part of the thalamus changed negatively with HbA{sub 1c}. Shape analysis is sensitive in identifying T2DM deep GM structural abnormalities and their relationships with cognitive impairments, which may greatly assist in clarifying the neural substrate of T2DM cognitive dysfunction. (orig.)

  11. Hemichorea in a diabetes mellitus patient following acute ischemic stroke with changes in regional cerebral blood flow

    Directory of Open Access Journals (Sweden)

    Yutaka Suzuki

    2015-03-01

    Full Text Available It is not unusual to observe hemichorea in patients with diabetes mellitus, with origins attributable to recent ischemia. Our patient was a 66-year-old female with diabetes mellitus who suddenly developed right hemichorea, mild muscle weakness of the right upper extremity, ideational apraxia, and acalculia. Her blood glucose was 600 mg/dL, and HbA1c was 13.3%. After the patient underwent head magnetic resonance imaging (MRI, a new cerebral infarction was observed in the left frontal lobe, and treatment was started with edaravone and cilostazol. At the same time, insulin treatment was also started for hyperglycemia. The acalculia and ideational apraxia improved approximately 1 week after treatment initiated, and the hemichorea also decreased. ECD-SPECT was performed on admission, and it was observed that blood flow was decreased in the left frontal lobe and striatum, but increased in the thalamus; two weeks later on follow-up ECD-SPECT, blood flow had increased slightly in the left forebrain and striatum, while it had decreased slightly in the thalamus. This suggests that the cause of hemichorea was related to ischemia. When the activity of the pallidum is impaired, it is presumed that the inhibitory activity towards the thalamus weakens and the thalamic cells become over-excited, causing chorea.

  12. The neurobiology of sound-specific auditory plasticity: a core neural circuit.

    Science.gov (United States)

    Xiong, Ying; Zhang, Yonghai; Yan, Jun

    2009-09-01

    Auditory learning or experience induces large-scale neural plasticity in not only the auditory cortex but also in the auditory thalamus and midbrain. Such plasticity is guided by acquired sound (sound-specific auditory plasticity). The mechanisms involved in this process have been studied from various approaches and support the presence of a core neural circuit consisting of a subcortico-cortico-subcortical tonotopic loop supplemented by neuromodulatory (e.g., cholinergic) inputs. This circuit has three key functions essential for establishing large-scale and sound-specific plasticity in the auditory cortex, auditory thalamus and auditory midbrain. They include the presence of sound information for guiding the plasticity, the communication between the cortex, thalamus and midbrain for coordinating the plastic changes and the adjustment of the circuit status for augmenting the plasticity. This review begins with an overview of sound-specific auditory plasticity in the central auditory system. It then introduces the core neural circuit which plays an essential role in inducing sound-specific auditory plasticity. Finally, the core neural circuit and its relationship to auditory learning and experience are discussed.

  13. Dynamics of circadian thalamocortical flow of information during a peripheral neuropathic pain condition

    Directory of Open Access Journals (Sweden)

    Helder eCardoso-Cruz

    2011-08-01

    Full Text Available It is known that the thalamocortical loop plays a crucial role in the encoding of sensory-discriminative features of painful stimuli. However, only a few studies have addressed the changes in thalamocortical dynamics that may occur after the onset of chronic pain. Our goal was to evaluate how the induction of chronic neuropathic pain affected the flow of information within the thalamocortical loop throughout the brain states of the sleep-wake cycle. To address this issue we recorded local field potentials – LFPs – both before and after the establishment of neuropathic pain in awake freely moving adult rats chronically implanted with arrays of multielectrodes in the lateral thalamus and primary somatosensory cortex. Our results show that the neuropathic injury induced changes in the number of wake and slow-wave-sleep state episodes, and especially in the total number of transitions between brain states. Moreover, partial directed coherence – PDC – analysis revealed that the amount of information flow between cortex and thalamus in neuropathic animals decreased significantly, indicating that the overall thalamic activity had less weight over the cortical activity. However, thalamocortical LFPs displayed higher phase-locking during awake and slow-wave-sleep episodes after the nerve lesion, suggesting faster transmission of relevant information along the thalamocortical loop. The observed changes are in agreement with the hypothesis of thalamic dysfunction after the onset of chronic pain, and may result from diminished inhibitory effect of the primary somatosensory cortex over the lateral thalamus.

  14. Maternal endotoxin exposure results in abnormal neuronal architecture in the newborn rabbit.

    Science.gov (United States)

    Balakrishnan, Bindu; Dai, Hui; Janisse, James; Romero, Roberto; Kannan, Sujatha

    2013-01-01

    Maternal intrauterine inflammation/infection is a potential risk factor for the development of neurologic disorders such as cerebral palsy (CP) in preterm and term infants. CP is associated with white matter and grey matter injury. In the current study, we used a rabbit model of CP in which pregnant rabbits are administered intrauterine injections of the endotoxin lipopolysaccharide. We then investigated the extent of neuronal damage in the newborn kit brain. We observed an overall decrease in the number of MAP2-stained neurons and an increase in Fluoro-Jade C-stained cells in the anterior thalamus of 1-day-old rabbit brain. We also observed an overall decrease in the number of branching points and spine density in the retrosplenial cortex, a major output region of the anterior thalamus that is involved in cognition and memory. The loss of spines and dendritic atrophy in the retrosplenial cortex may be caused by loss of presynaptic input from the thalamus. Our study indicates that the cognitive impairments seen in patients with CP may be related to the degeneration of neurons and abnormal arborization of the thalamic and cortical neurons.

  15. Tasting calories differentially affects brain activation during hunger and satiety.

    Science.gov (United States)

    van Rijn, Inge; de Graaf, Cees; Smeets, Paul A M

    2015-02-15

    An important function of eating is ingesting energy. Our objectives were to assess whether oral exposure to caloric and non-caloric stimuli elicits discriminable responses in the brain and to determine in how far these responses are modulated by hunger state and sweetness. Thirty women tasted three stimuli in two motivational states (hunger and satiety) while their brain responses were measured using functional magnetic resonance imaging in a randomized crossover design. Stimuli were solutions of sucralose (sweet, no energy), maltodextrin (non-sweet, energy) and sucralose+maltodextrin (sweet, energy). We found no main effect of energy content and no interaction between energy content and sweetness. However, there was an interaction between hunger state and energy content in the median cingulate (bilaterally), ventrolateral prefrontal cortex, anterior insula and thalamus. This indicates that the anterior insula and thalamus, areas in which hunger state and taste of a stimulus are integrated, also integrate hunger state with caloric content of a taste stimulus. Furthermore, in the median cingulate and ventrolateral prefrontal cortex, tasting energy resulted in more activation during satiety compared to hunger. This finding indicates that these areas, which are known to be involved in processes that require approach and avoidance, are also involved in guiding ingestive behavior. In conclusion, our results suggest that energy sensing is a hunger state dependent process, in which the median cingulate, ventrolateral prefrontal cortex, anterior insula and thalamus play a central role by integrating hunger state with stimulus relevance. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. [Impairments of gray matter in MRI-negative epileptic patients with different seizure types].

    Science.gov (United States)

    Quan, W; Xu, Q; Yang, F; Chen, G H; Lin, Z X; Zhang, Q R; Xiao, J H; Lu, G M; Zhang, Z Q

    2017-12-05

    Objective: To investigate the damage of gray matter structure in MRI-negative epilepsy patients with different symptoms by voxel-based morphometry (VBM). Methods: From June, 2009 to October, 2016, ninety MRI-negative epilepsy patients and thirty-five healthy volunteers underwent the 3T magnetic resonance imaging scan in Nanjing General Hospital. The patients were divided into three groups, including idiopathic generalized tonic-clonic seizure (I-GTCS), secondarily generalized tonic-clonic seizure (S-GTCS), and partial seizure (PS) according to different symptoms. The three-dimensional high-resolution T1 structural MRI data was obtained for the voxel-based morphometry. Data of gray matter structure from four groups were compared using one-way analysis of variance (ANOVA). An independent-sample t test was performed in order to compare gray matter volume of the three patient groups with controls respectively. According the results of ANOVA, impaired brain regions were selected as regions of interest in order to carry out correlation analysis between gray matter volume and disease duration. Results: ANOVA showed significant differences in gray matter structure of bilateral thalamus and frontal lobe between four groups (alphasim correction, P structure, especially in thalamus and frontal lobe. The impairments of thalamus and frontal lobe in patients with different seizure types are different with the progression of disease, which suggests that influences of different epilepsy seizures on the thalamo-cortical network are different.

  17. Diffusion-weighted imaging in normal fetal brain maturation

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, J.F. [University Children' s Hospital UKBB, Department of Pediatric Radiology, Basel (Switzerland); Confort-Gouny, S.; Le Fur, Y.; Viout, P.; Cozzone, P. [UMR-CNRS 6612, Faculte de Medecine, Universite de la Mediterranee, Centre de Resonance Magnetique Biologique et Medicale, Marseille (France); Bennathan, M.; Chapon, F.; Fogliarini, C.; Girard, N. [Universite de la Mediterranee, Department of Neuroradiology AP-HM Timone, Marseille (France)

    2007-09-15

    Diffusion-weighted imaging (DWI) provides information about tissue maturation not seen on conventional magnetic resonance imaging. The aim of this study is to analyze the evolution over time of the apparent diffusion coefficient (ADC) of normal fetal brain in utero. DWI was performed on 78 fetuses, ranging from 23 to 37 gestational weeks (GW). All children showed at follow-up a normal neurological evaluation. ADC values were obtained in the deep white matter (DWM) of the centrum semiovale, the frontal, parietal, occipital and temporal lobe, in the cerebellar hemisphere, the brainstem, the basal ganglia (BG) and the thalamus. Mean ADC values in supratentorial DWM areas (1.68 {+-} 0.05 mm{sup 2}/s) were higher compared with the cerebellar hemisphere (1.25 {+-} 0.06 mm{sup 2}/s) and lowest in the pons (1.11 {+-} 0.05 mm{sup 2}/s). Thalamus and BG showed intermediate values (1.25 {+-} 0.04 mm{sup 2}/s). Brainstem, cerebellar hemisphere and thalamus showed a linear negative correlation with gestational age. Supratentorial areas revealed an increase in ADC values, followed by a decrease after the 30th GW. This study provides a normative data set that allows insights in the normal fetal brain maturation in utero, which has not yet been observed in previous studies on premature babies. (orig.)

  18. Unique Distribution of Aromatase in the Human Brain: In Vivo Studies With PET and [N-Methyl-11C]Vorozole

    Energy Technology Data Exchange (ETDEWEB)

    Biegon, A.; Biegon, A.; Kim, S.W.; Alexoff, D.; Millard, J.; Carter, P.; Hubbard, B.; King, P.; Logan, J.; Muench, L.; Pareto, D.; Schlyer, D.; Shea, C.; Telang, F.; Wang, G.-J.; Xu, Y.; Fowler, J.

    2010-10-01

    Aromatase catalyzes the last step in estrogen biosynthesis. Brain aromatase is involved in diverse neurophysiological and behavioral functions including sexual behavior, aggression, cognition, and neuroprotection. Using positron emission tomography (PET) with the radiolabeled aromatase inhibitor [N-methyl-{sup 11}C]vorozole, we characterized the tracer distribution and kinetics in the living human brain. Six young, healthy subjects, three men and three women, were administered the radiotracer alone on two separate occasions. Women were scanned in distinct phases of the menstrual cycle. Specificity was confirmed by pretreatment with a pharmacological (2.5 mg) dose of the aromatase inhibitor letrozole. PET data were acquired over a 90-min period and regions of interest placed over selected brain regions. Brain and plasma time activity curves, corrected for metabolites, were used to derive kinetic parameters. Distribution volume (V{sub T}) values in both men and women followed the following rank order: thalamus > amygdala = preoptic area > medulla (inferior olive) > accumbens, pons, occipital and temporal cortex, putamen, cerebellum, and white matter. Pretreatment with letrozole reduced VT in all regions, though the size of the reduction was region-dependent, ranging from {approx}70% blocking in thalamus andpreoptic area to {approx}10% in cerebellum. The high levels of aromatase in thalamus and medulla (inferior olive) appear to be unique to humans. These studies set the stage for the noninvasive assessment of aromatase involvement in various physiological and pathological processes affecting the human brain.

  19. Broca's area - thalamic connectivity.

    Science.gov (United States)

    Bohsali, Anastasia A; Triplett, William; Sudhyadhom, Atchar; Gullett, Joseph M; McGregor, Keith; FitzGerald, David B; Mareci, Thomas; White, Keith; Crosson, Bruce

    2015-02-01

    Broca's area is crucially involved in language processing. The sub-regions of Broca's area (pars triangularis, pars opercularis) presumably are connected via corticocortical pathways. However, growing evidence suggests that the thalamus may also be involved in language and share some of the linguistic functions supported by Broca's area. Functional connectivity is thought to be achieved via corticothalamic/thalamocortical white matter pathways. Our study investigates structural connectivity between Broca's area and the thalamus, specifically ventral anterior nucleus and pulvinar. We demonstrate that Broca's area shares direct connections with these thalamic nuclei and suggest a local Broca's area-thalamus network potentially involved in linguistic processing. Thalamic connectivity with Broca's area may serve to selectively recruit cortical regions storing multimodal features of lexical items and to bind them together during lexical-semantic processing. In addition, Broca's area-thalamic circuitry may enable cortico-thalamo-cortical information transfer and modulation between BA 44 and 45 during language comprehension and production. Published by Elsevier Inc.

  20. Distribution of vesicular glutamate transporters in the human brain

    Directory of Open Access Journals (Sweden)

    Erika eVigneault

    2015-03-01

    Full Text Available Glutamate is the major excitatory transmitter in the brain. Vesicular glutamate transporters (VGLUT1-3 are responsible for uploading glutamate into synaptic vesicles. VGLUT1 and VGLUT2 are considered as specific markers of canonical glutamatergic neurons, while VGLUT3 is found in neurons previously shown to use other neurotransmitters than glutamate. Although there exists a rich literature on the localization of these glutamatergic markers in the rodent brain, little is currently known about the distribution of VGLUT1-3 in the human brain. In the present study, using subtype specific probes and antisera, we examined the localization of the three vesicular glutamate transporters in the human brain by in situ hybridization, immunoautoradiography and immunohistochemistry. We found that the VGLUT1 transcript was highly expressed in the cerebral cortex, hippocampus and cerebellum, whereas VGLUT2 mRNA was mainly found in the thalamus and brainstem. VGLUT3 mRNA was localized in scarce neurons within the cerebral cortex, hippocampus, striatum and raphe nuclei. Following immunoautoradiographic labeling, intense VGLUT1- and VGLUT2-immunoreactivities were observed in all regions investigated (cerebral cortex, hippocampus, caudate-putamen, cerebellum, thalamus, amygdala, substantia nigra, raphe while VGLUT3 was absent from the thalamus and cerebellum. This extensive mapping of VGLUT1-3 in human brain reveals distributions that correspond for the most part to those previously described in rodent brains.

  1. Subcortical correlates of individual differences in aptitude.

    Science.gov (United States)

    Jung, Rex E; Ryman, Sephira G; Vakhtin, Andrei A; Carrasco, Jessica; Wertz, Chris; Flores, Ranee A

    2014-01-01

    The study of individual differences encompasses broad constructs including intelligence, creativity, and personality. However, substantially less research is devoted to the study of specific aptitudes in spite of their importance to educational, occupational, and avocational success. We sought to determine subcortical brain structural correlates of several broad aptitudes including Math, Vocabulary, Foresight, Paper Folding, and Inductive Reasoning in a large (N = 107), healthy, young (age range  = 16-29) cohort. Subcortical volumes were measured using an automated technique (FreeSurfer) across structures including bilateral caudate, putamen, globus pallidus, thalamus, nucleus accumbens, hippocampus, amygdala, and five equal regions of the corpus callosum. We found that performance on measures of each aptitude was predicted by different subcortical structures: Math--higher right nucleus accumbens volume; Vocabulary--higher left hippocampus volume; Paper Folding--higher right thalamus volume; Foresight--lower right thalamus and higher mid anterior corpus callosum volume; Inductive Reasoning--higher mid anterior corpus callosum volume. Our results support general findings, within the cognitive neurosciences, showing lateralization of structure-function relationships, as well as more specific relationships between individual structures (e.g., left hippocampus) and functions relevant to particular aptitudes (e.g., Vocabulary).

  2. Subcortical correlates of individual differences in aptitude.

    Directory of Open Access Journals (Sweden)

    Rex E Jung

    Full Text Available The study of individual differences encompasses broad constructs including intelligence, creativity, and personality. However, substantially less research is devoted to the study of specific aptitudes in spite of their importance to educational, occupational, and avocational success. We sought to determine subcortical brain structural correlates of several broad aptitudes including Math, Vocabulary, Foresight, Paper Folding, and Inductive Reasoning in a large (N = 107, healthy, young (age range  = 16-29 cohort. Subcortical volumes were measured using an automated technique (FreeSurfer across structures including bilateral caudate, putamen, globus pallidus, thalamus, nucleus accumbens, hippocampus, amygdala, and five equal regions of the corpus callosum. We found that performance on measures of each aptitude was predicted by different subcortical structures: Math--higher right nucleus accumbens volume; Vocabulary--higher left hippocampus volume; Paper Folding--higher right thalamus volume; Foresight--lower right thalamus and higher mid anterior corpus callosum volume; Inductive Reasoning--higher mid anterior corpus callosum volume. Our results support general findings, within the cognitive neurosciences, showing lateralization of structure-function relationships, as well as more specific relationships between individual structures (e.g., left hippocampus and functions relevant to particular aptitudes (e.g., Vocabulary.

  3. Resting-state fMRI revealed different brain activities responding to valproic acid and levetiracetam in benign epilepsy with central-temporal spikes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qirui; Zhang, Zhiqiang; Xu, Qiang; Wu, Han; Li, Zhipeng; Lu, Guangming [Nanjing University School of Medicine, Department of Medical Imaging, Jinling Hospital, Nanjing (China); Yang, Fang; Li, Qian [Nanjing University School of Medicine, Department of Neurology, Jinling Hospital, Nanjing (China); Hu, Zheng [Nanjing Children' s Hospital, Department of Neurology, Nanjing (China); Dante, Mantini [Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven (Belgium); Li, Kai [Suzhou University, Laboratory of Molecular Medicine, Suzhou (China)

    2017-05-15

    Our aim was to investigate regional difference in brain activities in response to antiepileptic drug (AED) medications in benign epilepsy with central-temporal spikes (BECTS) using resting-state functional magnetic resonance imaging (fMRI). Fifty-seven patients with BECTS underwent resting-state fMRI scans after receiving either valproic acid (VPA) (n = 15), levetiracetam (LEV) (n = 21), or no medication (n = 21). fMRI regional homogeneity (ReHo) parameter among the three groups of patients were compared and were correlated with total doses of AED in the two medicated groups. Compared with patients on no-medication, patients receiving either VPA or LEV showed decreased ReHo in the central-temporal region, frontal cortex, and thalamus. In particular, the VPA group showed greater ReHo decrease in the thalamus and milder in cortices and caudate heads compared with the LEV group. In addition, the VPA group demonstrated a negative correlation between ReHo values in the central-temporal region and medication dose. Both VPA and LEV inhibit resting-state neural activity in the central-temporal region, which is the main epileptogenic focus of BECTS. VPA reduced brain activity in the cortical epileptogenic regions and thalamus evenly, whereas LEV reduced brain activity predominantly in the cortices. Interestingly, VPA showed a cumulative effect on inhibiting brain activity in the epileptogenic regions in BECTS. (orig.)

  4. Transneuronal degeneration in patients with temporal lobe epilepsy: evaluation by MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, Fumiko; Ogawa, Toshihide; Sugihara, Shuji; Kamba, Masayuki; Kinoshita, Toshibumi [Department of Radiology, Faculty of Medicine' ' Tottori University, 36-1 Nishi-cho, 683-8504, Yonago, Tottori (Japan); Kohaya, Norimasa; Kondo, Shinji [Department of Neurosurgery, Faculty of Medicine' ' Tottori University, 36-1 Nishi-cho, 683-8504, Yonago, Tottori (Japan)

    2003-09-01

    The aim of this study was to assess the MR imaging findings of transneuronal degeneration of limbic system in the patients with temporal lobe epilepsy, and to detect the influence of surgery on the anatomy of the limbic system. Axial and coronal T1- and T2-weighted MR images were retrospectively analyzed in 34 patients with temporal lobe epilepsy, focusing on transneuronal degeneration. In 17 of the 34 patients, MR images were also analyzed after selective amygdalo-hippocampectomy. Atrophy of the fornix, mamillary body, mamillothalamic tract (MTT), and thalamus ipsilateral to the epileptic focus was demonstrated on MR images in 14.7, 17.6, 8.8, and 11.8% of the 34 patients, respectively. Focal hyperintensity of the thalamus was found on T2-weighted images in 8.8% of the 34 patients. In 17 patients who were evaluated before and after surgery, transneuronal degeneration was seen more frequently after surgery: fornix (11.8 vs 29.4%), mamillary body (11.8 vs 52.9%), MTT (5.9 vs 11.8%), and thalamus (11.8 vs 11.8%). Transneuronal degeneration of the limbic system is clearly demonstrated by MR imaging in patients with temporal lobe epilepsy, and surgical intervention induces transneuronal degeneration more frequently. (orig.)

  5. Unified thalamic model generates multiple distinct oscillations with state-dependent entrainment by stimulation.

    Science.gov (United States)

    Li, Guoshi; Henriquez, Craig S; Fröhlich, Flavio

    2017-10-01

    The thalamus plays a critical role in the genesis of thalamocortical oscillations, yet the underlying mechanisms remain elusive. To understand whether the isolated thalamus can generate multiple distinct oscillations, we developed a biophysical thalamic model to test the hypothesis that generation of and transition between distinct thalamic oscillations can be explained as a function of neuromodulation by acetylcholine (ACh) and norepinephrine (NE) and afferent synaptic excitation. Indeed, the model exhibited four distinct thalamic rhythms (delta, sleep spindle, alpha and gamma oscillations) that span the physiological states corresponding to different arousal levels from deep sleep to focused attention. Our simulation results indicate that generation of these distinct thalamic oscillations is a result of both intrinsic oscillatory cellular properties and specific network connectivity patterns. We then systematically varied the ACh/NE and input levels to generate a complete map of the different oscillatory states and their transitions. Lastly, we applied periodic stimulation to the thalamic network and found that entrainment of thalamic oscillations is highly state-dependent. Our results support the hypothesis that ACh/NE modulation and afferent excitation define thalamic oscillatory states and their response to brain stimulation. Our model proposes a broader and more central role of the thalamus in the genesis of multiple distinct thalamo-cortical rhythms than previously assumed.

  6. Revisiting Brain Atrophy and Its Relationship to Disability in Multiple Sclerosis

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    Shiee, Navid; Bazin, Pierre-Louis; Zackowski, Kathleen M.; Farrell, Sheena K.; Harrison, Daniel M.; Newsome, Scott D.; Ratchford, John N.; Caffo, Brian S.; Calabresi, Peter A.; Pham, Dzung L.; Reich, Daniel S.

    2012-01-01

    Background Brain atrophy is a well-accepted imaging biomarker of multiple sclerosis (MS) that partially correlates with both physical disability and cognitive impairment. Methodology/Principal Findings Based on MRI scans of 60 MS cases and 37 healthy volunteers, we measured the volumes of white matter (WM) lesions, cortical gray matter (GM), cerebral WM, caudate nucleus, putamen, thalamus, ventricles, and brainstem using a validated and completely automated segmentation method. We correlated these volumes with the Expanded Disability Status Scale (EDSS), MS Severity Scale (MSSS), MS Functional Composite (MSFC), and quantitative measures of ankle strength and toe sensation. Normalized volumes of both cortical and subcortical GM structures were abnormally low in the MS group, whereas no abnormality was found in the volume of the cerebral WM. High physical disability was associated with low cerebral WM, thalamus, and brainstem volumes (partial correlation coefficients ∼0.3–0.4) but not with low cortical GM volume. Thalamus volumes were inversely correlated with lesion load (r = −0.36, p<0.005). Conclusion The GM is atrophic in MS. Although lower WM volume is associated with greater disability, as might be expected, WM volume was on average in the normal range. This paradoxical result might be explained by the presence of coexisting pathological processes, such as tissue damage and repair, that cause both atrophy and hypertrophy and that underlie the observed disability. PMID:22615886

  7. Revisiting brain atrophy and its relationship to disability in multiple sclerosis.

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    Navid Shiee

    Full Text Available Brain atrophy is a well-accepted imaging biomarker of multiple sclerosis (MS that partially correlates with both physical disability and cognitive impairment.Based on MRI scans of 60 MS cases and 37 healthy volunteers, we measured the volumes of white matter (WM lesions, cortical gray matter (GM, cerebral WM, caudate nucleus, putamen, thalamus, ventricles, and brainstem using a validated and completely automated segmentation method. We correlated these volumes with the Expanded Disability Status Scale (EDSS, MS Severity Scale (MSSS, MS Functional Composite (MSFC, and quantitative measures of ankle strength and toe sensation. Normalized volumes of both cortical and subcortical GM structures were abnormally low in the MS group, whereas no abnormality was found in the volume of the cerebral WM. High physical disability was associated with low cerebral WM, thalamus, and brainstem volumes (partial correlation coefficients ~0.3-0.4 but not with low cortical GM volume. Thalamus volumes were inversely correlated with lesion load (r = -0.36, p<0.005.The GM is atrophic in MS. Although lower WM volume is associated with greater disability, as might be expected, WM volume was on average in the normal range. This paradoxical result might be explained by the presence of coexisting pathological processes, such as tissue damage and repair, that cause both atrophy and hypertrophy and that underlie the observed disability.

  8. Tensor-based morphometry and stereology reveal brain pathology in the complexin1 knockout mouse.

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    Catherine Kielar

    Full Text Available Complexins (Cplxs are small, soluble, regulatory proteins that bind reversibly to the SNARE complex and modulate synaptic vesicle release. Cplx1 knockout mice (Cplx1(-/- have the earliest known onset of ataxia seen in a mouse model, although hitherto no histopathology has been described in these mice. Nevertheless, the profound neurological phenotype displayed by Cplx1(-/- mutants suggests that significant functional abnormalities must be present in these animals. In this study, MRI was used to automatically detect regions where structural differences were not obvious when using a traditional histological approach. Tensor-based morphometry of Cplx1(-/- mouse brains showed selective volume loss from the thalamus and cerebellum. Stereological analysis of Cplx1(-/- and Cplx1(+/+ mice brain slices confirmed the volume loss in the thalamus as well as loss in some lobules of the cerebellum. Finally, stereology was used to show that there was loss of cerebellar granule cells in Cplx1(-/- mice when compared to Cplx1(+/+ animals. Our study is the first to describe pathological changes in Cplx1(-/- mouse brain. We suggest that the ataxia in Cplx1(-/- mice is likely to be due to pathological changes in both cerebellum and thalamus. Reduced levels of Cplx proteins have been reported in brains of patients with neurodegenerative diseases. Therefore, understanding the effects of Cplx depletion in brains from Cplx1(-/- mice may also shed light on the mechanisms underlying pathophysiology in disorders in which loss of Cplx1 occurs.

  9. Ataxic hemiparesis: neurophysiological analysis by cerebellar transcranial magnetic stimulation.

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    Kikuchi, Saeko; Mochizuki, Hitoshi; Moriya, Arata; Nakatani-Enomoto, Setsu; Nakamura, Koichiro; Hanajima, Ritsuko; Ugawa, Yoshikazu

    2012-03-01

    The aim of this study was to investigate physiological mechanisms underlying ataxia in patients with ataxic hemiparesis. Subjects were three patients with ataxic hemiparesis, whose responsible lesion was located at the posterior limb of internal capsule (case 1), thalamus (case 2), or pre- and post-central gyri (case 3). Paired-pulse transcranial magnetic stimulation (TMS) technique was used to evaluate connectivity between the cerebellum and contralateral motor cortex. The conditioning cerebellar stimulus was given over the cerebellum and the test stimulus over the primary motor cortex. We studied how the conditioning stimulus modulated motor evoked potentials (MEPs) to the cortical test stimulus. In non-ataxic limbs, the cerebellar stimulus normally suppressed cortical MEPs. In ataxic limbs, the cerebellar inhibition was not elicited in patients with a lesion at the posterior limb of internal capsule (case 1) or thalamus (case 2). In contrast, normal cerebellar inhibition was elicited in the ataxic limb in a patient with a lesion at sensori-motor cortex (case 3). Lesions at the internal capsule and thalamus involved the cerebello-thalamo-cortical pathways and reduced the cerebellar suppression effect. On the other hand, a lesion at the pre- and post-central gyri should affect cortico-pontine pathway but not involve the cerebello-thalamo-cortical pathways. This lack of cerebello-talamo-cortical pathway involvement may explain normal suppression in this patient. The cerebellar TMS method can differentiate cerebellar efferent ataxic hemiparesis from cerebellar afferent ataxic hemiparesis.

  10. Mapping abnormal subcortical brain morphometry in an elderly HIV+ cohort

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    Benjamin S.C. Wade

    2015-01-01

    Full Text Available Over 50% of HIV+ individuals exhibit neurocognitive impairment and subcortical atrophy, but the profile of brain abnormalities associated with HIV is still poorly understood. Using surface-based shape analyses, we mapped the 3D profile of subcortical morphometry in 63 elderly HIV+ participants and 31 uninfected controls. The thalamus, caudate, putamen, pallidum, hippocampus, amygdala, brainstem, accumbens, callosum and ventricles were segmented from high-resolution MRIs. To investigate shape-based morphometry, we analyzed the Jacobian determinant (JD and radial distances (RD defined on each region's surfaces. We also investigated effects of nadir CD4+ T-cell counts, viral load, time since diagnosis (TSD and cognition on subcortical morphology. Lastly, we explored whether HIV+ participants were distinguishable from unaffected controls in a machine learning context. All shape and volume features were included in a random forest (RF model. The model was validated with 2-fold cross-validation. Volumes of HIV+ participants' bilateral thalamus, left pallidum, left putamen and callosum were significantly reduced while ventricular spaces were enlarged. Significant shape variation was associated with HIV status, TSD and the Wechsler adult intelligence scale. HIV+ people had diffuse atrophy, particularly in the caudate, putamen, hippocampus and thalamus. Unexpectedly, extended TSD was associated with increased thickness of the anterior right pallidum. In the classification of HIV+ participants vs. controls, our RF model attained an area under the curve of 72%.

  11. Decreased T2 signal in the thalami may be a sign of lysosomal storage disease

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    Autti, Taina [Helsinki University Central Hospital, Helsinki Medical Imaging Center, P.O. Box 340, Helsinki (Finland); Joensuu, Raimo [AstraZeneca R and D Molndal, Moelndal (Sweden); Aaberg, Laura [University of Helsinki, Department of Child Neurology, Hospital for Children and Adolescents, Helsinki (Finland)

    2007-07-15

    Lysosomal disorders are rare and are caused by genetically transmitted lysosomal enzyme deficiencies. A decreased T2 signal in the thalamus has occasionally been reported. Because the finding of bilateral abnormal signal intensity of the thalamus on T2-weighted images has not been systematically reviewed, and its value as a diagnostic tool critically evaluated, we carried out a systematic review of the literature. Articles in English with 30 trios of keywords were collected from PubMed. Exclusion criteria were lack of conventional T2-weighted images in the protocol and not being a human study. Finally, 111 articles were included. The thalamus was considered affected only if mentioned in the text or in the figure legends. Some 117 patients with various lysosomal diseases and five patients with ceruloplasmin deficiency were reported to have a bilateral decrease in T2 signal intensity. At least one article reported a bilateral decrease in signal intensity of the thalami on T2-weighted images in association with GM1 and GM2 gangliosidosis and with Krabbe's disease, aspartylglucosaminuria, mannosidosis, fucosidosis, and mucolipidosis IV. Furthermore, thalamic alteration was a consistent finding in several types of neuronal ceroid lipofuscinosis (NCL) including CLN1 (infantile NCL), CLN2 (classic late infantile NCL), CLN3 (juvenile NCL), CLN5 (Finnish variant late infantile NCL), and CLN7 (Turkish variant late infantile NCL). A decrease in T2 signal intensity in the thalami seems to be a sign of lysosomal disease. (orig.)

  12. Unique distribution of aromatase in the human brain: in vivo studies with PET and [N-methyl-11C]vorozole.

    Science.gov (United States)

    Biegon, Anat; Kim, Sung Won; Alexoff, David L; Jayne, Millard; Carter, Pauline; Hubbard, Barbara; King, Payton; Logan, Jean; Muench, Lisa; Pareto, Deborah; Schlyer, David; Shea, Colleen; Telang, Frank; Wang, Gene-Jack; Xu, Youwen; Fowler, Joanna S

    2010-11-01

    Aromatase catalyzes the last step in estrogen biosynthesis. Brain aromatase is involved in diverse neurophysiological and behavioral functions including sexual behavior, aggression, cognition, and neuroprotection. Using positron emission tomography (PET) with the radiolabeled aromatase inhibitor [N-methyl-(11)C]vorozole, we characterized the tracer distribution and kinetics in the living human brain. Six young, healthy subjects, three men and three women, were administered the radiotracer alone on two separate occasions. Women were scanned in distinct phases of the menstrual cycle. Specificity was confirmed by pretreatment with a pharmacological (2.5 mg) dose of the aromatase inhibitor letrozole. PET data were acquired over a 90-min period and regions of interest placed over selected brain regions. Brain and plasma time activity curves, corrected for metabolites, were used to derive kinetic parameters. Distribution volume (V(T)) values in both men and women followed the following rank order: thalamus > amygdala = preoptic area > medulla (inferior olive) > accumbens, pons, occipital and temporal cortex, putamen, cerebellum, and white matter. Pretreatment with letrozole reduced V(T) in all regions, though the size of the reduction was region-dependent, ranging from ∼70% blocking in thalamus andpreoptic area to ∼10% in cerebellum. The high levels of aromatase in thalamus and medulla (inferior olive) appear to be unique to humans. These studies set the stage for the noninvasive assessment of aromatase involvement in various physiological and pathological processes affecting the human brain.

  13. Changes in functional network centrality underlie cognitive dysfunction and physical disability in multiple sclerosis.

    Science.gov (United States)

    Schoonheim, M M; Geurts, Jjg; Wiebenga, O T; De Munck, J C; Polman, C H; Stam, C J; Barkhof, F; Wink, A M

    2014-07-01

    Cognitive dysfunction in multiple sclerosis (MS) has a large impact on the quality of life and is poorly understood. The aim of this study was to investigate functional network integrity in MS, and relate this to cognitive dysfunction and physical disability. Resting state fMRI scans were included of 128 MS patients and 50 controls. Eigenvector centrality mapping (ECM) was applied, a graph analysis technique that ranks the importance of brain regions based on their connectivity patterns. Significant ECM changes were related to physical disability and cognitive dysfunction. In MS patients, ECM values were increased in bilateral thalamus and posterior cingulate (PCC) areas, and decreased in sensorimotor and ventral stream areas. Sensorimotor ECM decreases were related to higher EDSS (rho = -0.24, p = 0.007), while ventral stream decreases were related to poorer average cognition (rho = 0.23, p = 0.009). The thalamus displayed increased connectivity to sensorimotor and ventral stream areas. In MS, areas in the ventral stream and sensorimotor cortex appear to become less central in the entire functional network of the brain, which is associated with clinico-cognitive dysfunction. The thalamus, however, displays increased connectivity with these areas. These findings may aid in further elucidating the function of functional reorganization processes in MS. © The Author(s) 2013.

  14. Intrinsic properties of and thalamocortical inputs onto identified corticothalamic-VPM neurons.

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    Yang, Qizong; Chen, Chia-Chien; Ramos, Raddy L; Katz, Elizabeth; Keller, Asaf; Brumberg, Joshua C

    2014-06-01

    Corticothalamic (CT) feedback plays an important role in regulating the sensory information that the cortex receives. Within the somatosensory cortex layer VI originates the feedback to the ventral posterior medial (VPM) nucleus of the thalamus, which in turn receives sensory information from the contralateral whiskers. We examined the physiology and morphology of CT neurons in rat somatosensory cortex, focusing on the physiological characteristics of the monosynaptic inputs that they receive from the thalamus. To identify CT neurons, rhodamine microspheres were injected into VPM and allowed to retrogradely transport to the soma of CT neurons. Thalamocortical slices were prepared at least 3 days post injection. Whole-cell recordings from labeled CT cells in layer VI demonstrated that they are regular spiking neurons and exhibit little spike frequency adaption. Two anatomical classes were identified based on their apical dendrites that either terminated by layer V (compact cells) or layer IV (elaborate cells). Thalamic inputs onto identified CT-VPM neurons demonstrated paired pulse depression over a wide frequency range (2-20 Hz). Stimulus trains also resulted in significant synaptic depression above 10 Hz. Our results suggest that thalamic inputs differentially impact CT-VPM neurons in layer VI. This characteristic may allow them to differentiate a wide range of stimulation frequencies which in turn further tune the feedback signals to the thalamus.

  15. Functional neuroimaging abnormalities in idiopathic generalized epilepsy

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    Megan L. McGill

    2014-01-01

    Full Text Available Magnetic resonance imaging (MRI techniques have been used to quantitatively assess focal and network abnormalities. Idiopathic generalized epilepsy (IGE is characterized by bilateral synchronous spike–wave discharges on electroencephalography (EEG but normal clinical MRI. Dysfunctions involving the neocortex, particularly the prefrontal cortex, and thalamus likely contribute to seizure activity. To identify possible morphometric and functional differences in the brains of IGE patients and normal controls, we employed measures of thalamic volumes, cortical thickness, gray–white blurring, fractional anisotropy (FA measures from diffusion tensor imaging (DTI and fractional amplitude of low frequency fluctuations (fALFF in thalamic subregions from resting state functional MRI. Data from 27 patients with IGE and 27 age- and sex-matched controls showed similar thalamic volumes, cortical thickness and gray–white contrast. There were no differences in FA values on DTI in tracts connecting the thalamus and prefrontal cortex. Functional analysis revealed decreased fALFF in the prefrontal cortex (PFC subregion of the thalamus in patients with IGE. We provide minimum detectable effect sizes for each measure used in the study. Our analysis indicates that fMRI-based methods are more sensitive than quantitative structural techniques for characterizing brain abnormalities in IGE.

  16. Glutamatergic alterations in the cortex of genetic absence epilepsy rats

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    Didier-Bazes Marianne

    2007-08-01

    Full Text Available Abstract Background In absence epilepsy, the neuronal hyper-excitation and hyper-synchronization, which induce spike and wave discharges in a cortico-thalamic loop are suspected to be due to an imbalance between GABA and glutamate (GLU neurotransmission. In order to elucidate the role played by GLU in disease outcome, we measured cortical and thalamic extracellular levels of GLU and GABA. We used an in vivo quantitative microdialysis approach (no-net-flux method in an animal model of absence epilepsy (GAERS. In addition, by infusing labelled glutamate through the microdialysis probe, we studied in vivo glutamate uptake in the cortex and thalamus in GAERS and non-epileptic control (NEC rats. Expression of the vesicular glutamate transporters VGLUT1 and VGLUT2 and a synaptic component, synaptophysin, was also measured. Results Although extracellular concentrations of GABA and GLU in the cortex and thalamus were not significantly different between GAERS and NEC rats, cortical GLU uptake was significantly decreased in unrestrained awake GAERS. Expression of VGLUT2 and synaptophysin was increased in the cortex of GAERS compared to NEC rats, but no changes were observed in the thalamus. Conclusion The specific decrease in GLU uptake in the cortex of GAERS linked to synaptic changes suggests impairment of the glutamatergic terminal network. These data support the idea that a change in glutamatergic neurotransmission in the cortex could contribute to hyperexcitability in absence epilepsy.

  17. Caloric Vestibular Stimulation Reduces Pain and Somatoparaphrenia in a Severe Chronic Central Post-Stroke Pain Patient: A Case Study.

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    Grazia Fernanda Spitoni

    Full Text Available Central post-stroke pain is a neuropathic syndrome characterized by intolerable contralesional pain and, in rare cases, somatic delusions. To date, there is limited evidence for the effective treatments of this disease. Here we used caloric vestibular stimulation to reduce pain and somatoparaphrenia in a 57-year-old woman suffering from central post-stroke pain. Resting-state functional magnetic resonance imaging was used to assess the neurological effects of this treatment. Following vestibular stimulation we observed impressive improvements in motor skills, pain, and somatic delusions. In the functional connectivity study before the vestibular stimulation, we observed differences in the patient's left thalamus functional connectivity, with respect to the thalamus connectivity of a control group (N = 20, in the bilateral cingulate cortex and left insula. After the caloric stimulation, the left thalamus functional connectivity with these regions, which are known to be involved in the cortical response to pain, disappeared as in the control group. The beneficial use of vestibular stimulation in the reduction of pain and somatic delusion in a CPSP patient is now documented by behavioral and imaging data. This evidence can be applied to theoretical models of pain and body delusions.

  18. Alterations in brain Protein Kinase A activity and reversal of morphine tolerance by two fragments of native Protein Kinase A inhibitor peptide (PKI).

    Science.gov (United States)

    Dalton, George D; Smith, Forrest L; Smith, Paul A; Dewey, William L

    2005-04-01

    Two peptide fragments of native Protein Kinase A inhibitor (PKI), PKI-(6-22)-amide and PKI-(Myr-14-22)-amide, significantly reversed low-level morphine antinociceptive tolerance in mice. The inhibition of Protein Kinase A (PKA) activity by both peptide fragments was then measured in specific brain regions (thalamus, periaqueductal gray (PAG), and medulla) and in lumbar spinal cord (LSC), which in previous studies have been shown to play a role in morphine-induced analgesia. In drug naive animals, cytosolic PKA activity was greater than particulate PKA activity in each region, while cytosolic and particulate PKA activities were greater in thalamus and PAG compared to medulla and LSC. The addition of both peptides to homogenates from each region completely abolished cytosolic and particulate PKA activities in vitro. Following injection into the lateral ventricle of the brain of drug naive mice and morphine-tolerant mice, both peptides inhibited PKA activity in the cytosolic, but not the particulate fraction of LSC. In addition, cytosolic and particulate PKA activities were inhibited by both peptides in thalamus. These results demonstrate that the inhibition of PKA reverses morphine tolerance. Moreover, the inhibition of PKA activity in specific brain regions and LSC from morphine-tolerant mice by PKI analogs administered i.c.v. is evidence that PKA plays a role in morphine tolerance.

  19. Evaluation of periventricular radiolucency in hydrocephalus by dynamic CT studies

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    Nakano, Hideki; Bandou, Kuniaki; Miyaoka, Makoto (Fujisawa City Hospital, Kanagawa (Japan))

    1994-06-01

    The association of periventricular radiolucency (PVL) in normal pressure hydrocephalus (NPH) on CT scan is a common finding. However, it is difficult to differentiate NPH from atrophy or infarctions in which shunt surgery does not reverse these conditions. To distinguish NPH from these, we examined PVL by means of dynamic CT (DCT) studies. We investigated 12 elderly patients presenting with gait disturbance, urinary incontinence and mental dysfunction who had both enlarged lateral ventricles and PVL. All patients had laboratory investigations, including radioisotope and CT cisternography and Xenon CBF studies. Nine patients were shunted because of abnormal CSF dynamics. Varying degrees of clinical improvement after surgery were observed in 6 cases. A difference of arrival time (AT) between PVL and thalamus obtained from time-density-curve was calculated in each patient. The AT difference was 6.2[+-]1.5 sec. in the shunt-effective group, and 1.4[+-]1.3 sec. in both, the shunt in effective and ineligible group, this was highly significant (p<0.01). We also measured peak time (PT) in PVL, of the thalamus and anterior cerebral artery, but no significant correlation was obtained. An AT difference between PVL and thalamus obtained from DCT studies is a clinically useful diagnostic tool for the evaluation of NPH. (author).

  20. Regional cerebral blood flow in fibromyalgia

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    Kwiatek, R.; Barnden, L.; Rowe, C.; McKinnon, J.; Pile, K. [The Queen Elizabeth Hospital , Adelaide, SA (Australia)

    1998-06-01

    Full text: Little is known of the aetiology of fibromyalgia (FM), a condition diagnosed on the basis of widespread chronic pain and multiple tender points. We have used Tc-99m HMPAO SPECT to compare regional cerebral bloodflow (rCBF) in 17 women who fulfill American College of Rheumatology criteria for FM to 22 age, sex and education matched controls. Both Statistical Parametric Mapping (SPM95) and coregistered MRI guided ROI were used for analysis. SPM95 revealed statistically significant hypoperfusion in the pontine tegmentum (p=0.048) and a trend to hypoperfusion in the left putamen (p=0.07). MRI guided ROI placement by an operator blinded to clinical information and the coregistered SPECT images, confirmed significant hypoperfusion of the left thalamus (p<0.0001) and the pontine tegmentum (p=0.001) and revealed trends towards hypoperfusion in the caudate nuclei and right thalamus. These results are consistent with the hypothesis that FM is due to dysfunction of central pain pathways. Spinothalamic neurones are known to be involved in pain perception and there are synapse connections to the thalamus in the gigantocellular part of the medulla and pons

  1. Methanol extract of Nigella sativa seed induces changes in the levels of neurotransmitter amino acids in male rat brain regions.

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    El-Naggar, Tarek; Carretero, María Emilia; Arce, Carmen; Gómez-Serranillos, María Pilar

    2017-12-01

    Nigella sativa L. (Ranunculaceae) (NS) has been used for medicinal and culinary purposes. Different parts of the plant are used to treat many disorders. This study investigates the effects of NS methanol extract on brain neurotransmitter amino acid levels. We measured the changes in aspartate, glutamate, glycine and γ-aminobutyric acid in five brain regions of male Wistar rats after methanol extract treatment. Animals were injected intraperitoneally with saline solution (controls) or NS methanol extract (equivalent of 2.5 g/kg body weight) and sacrificed 1 h later or after administering 1 daily dose for 8 days. The neurotransmitters were measured in the hypothalamus, cortex, striatum, hippocampus and thalamus by HPLC. Results showed significant changes in amino acids compared to basal values. Glutamate increased significantly (16-36%) in the regions analyzed except the striatum. Aspartate in the hypothalamus (50 and 76%) and glycine in hippocampus (32 and 25%), thalamus (66 and 29%) and striatum (75 and 48%) also increased with the two treatment intervals. γ-Aminobutyric acid significantly increased in the hippocampus (38 and 32%) and thalamus (22 and 40%) but decreased in the cortex and hypothalamus although in striatum only after eight days of treatment (24%). Our results suggest that injected methanol extract modifies amino acid levels in the rat brain regions. These results could be of interest since some neurodegenerative diseases are related to amino acid level imbalances in the central nervous system, suggesting the prospect for therapeutic use of NS against these disorders.

  2. Metabotropic glutamate receptors as a strategic target for the treatment of epilepsy.

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    Alexander, Georgia M; Godwin, Dwayne W

    2006-09-01

    Epilepsy is a chronic neurological disorder that has many known types, including generalized epilepsies that involve cortical and subcortical structures. A proportion of patients have seizures that are resistant to traditional anti-epilepsy drugs, which mainly target ion channels or postsynaptic receptors. This resistance to conventional therapies makes it important to identify novel targets for the treatment of epilepsy. Given the involvement of the neurotransmitter glutamate in the etiology of epilepsy, targets that control glutamatergic neurotransmission are of special interest. The metabotropic glutamate receptors (mGluRs) are of a family of eight G-protein-coupled receptors that serve unique regulatory functions at synapses that use the neurotransmitter glutamate. Their distribution within the central nervous system provides a platform for both presynaptic control of glutamate release, as well as postsynaptic control of neuronal responses to glutamate. In recent years, substantial efforts have been made towards developing selective agonists and antagonists which may be useful for targeting specific receptor subtypes in an attempt to harness the therapeutic potential of these receptors. We examine the possibility of intervening at these receptors by considering the specific example of absence seizures, a form of generalized, non-convulsive seizure that involves the thalamus. Views of the etiology of absence seizures have evolved over time from the "centrencephalic" concept of a diffuse subcortical pacemaker toward the "cortical focus" theory in which cortical hyperexcitability leads the thalamus into the 3-4 Hz rhythms that are characteristic of absence seizures. Since the cortex communicates with the thalamus via a massive glutamatergic projection, ionotropic glutamate receptor (iGluR) blockade has held promise, but the global nature of iGluR intervention has precluded the clinical effectiveness of drugs that block iGluRs. In contrast, mGluRs, because they

  3. Regional thalamic neuropathology in patients with hippocampal sclerosis and epilepsy: A postmortem study

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    Sinjab, Barah; Martinian, Lillian; Sisodiya, Sanjay M; Thom, Maria

    2013-01-01

    Purpose Clinical, experimental, and neuroimaging data all indicate that the thalamus is involved in the network of changes associated with temporal lobe epilepsy (TLE), particularly in association with hippocampal sclerosis (HS), with potential roles in seizure initiation and propagation. Pathologic changes in the thalamus may be a result of an initial insult, ongoing seizures, or retrograde degeneration through reciprocal connections between thalamic and limbic regions. Our aim was to carry out a neuropathologic analysis of the thalamus in a postmortem (PM) epilepsy series, to assess the distribution, severity, and nature of pathologic changes and its association with HS. Methods Twenty-four epilepsy PM cases (age range 25–87 years) and eight controls (age range 38–85 years) were studied. HS was classified as unilateral (UHS, 11 cases), bilateral (BHS, 4 cases) or absent (No-HS, 9 cases). Samples from the left and right sides of the thalamus were stained with cresyl violet (CV), and for glial firbillary acidic protein (GFAP) and synaptophysin. Using image analysis, neuronal densities (NDs) or field fraction staining values (GFAP, synaptophysin) were measured in four thalamic nuclei: anteroventral nucleus (AV), lateral dorsal nucleus (LD), mediodorsal nucleus (MD), and ventrolateral nucleus (VL). The results were compared within and between cases. Key Findings The severity, nature, and distribution of thalamic pathology varied between cases. A pattern that emerged was a preferential involvement of the MD in UHS cases with a reduction in mean ND ipsilateral to the side of HS (p = 0.05). In UHS cases, greater field fraction values for GFAP and lower values for synaptophysin and ND were seen in the majority of cases in the MD ipsilateral to the side of sclerosis compared to other thalamic nuclei. In addition, differences in the mean ND between classical HS, atypical HS, and No-HS cases were noted in the ipsilateral MD (p < 0.05), with lower values observed in

  4. Determining the Neural Substrate for Encoding a Memory of Human Pain and the Influence of Anxiety.

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    Tseng, Ming-Tsung; Kong, Yazhuo; Eippert, Falk; Tracey, Irene

    2017-12-06

    To convert a painful stimulus into a briefly maintainable construct when the painful stimulus is no longer accessible is essential to guide human behavior and avoid dangerous situations. Because of the aversive nature of pain, this encoding process might be influenced by emotional aspects and could thus vary across individuals, but we have yet to understand both the basic underlying neural mechanisms as well as potential interindividual differences. Using fMRI in combination with a delayed-discrimination task in healthy volunteers of both sexes, we discovered that brain regions involved in this working memory encoding process were dissociable according to whether the to-be-remembered stimulus was painful or not, with the medial thalamus and the rostral anterior cingulate cortex encoding painful and the primary somatosensory cortex encoding nonpainful stimuli. Encoding of painful stimuli furthermore significantly enhanced functional connectivity between the thalamus and medial prefrontal cortex (mPFC). With regards to emotional aspects influencing encoding processes, we observed that more anxious participants showed significant performance advantages when encoding painful stimuli. Importantly, only during the encoding of pain, the interindividual differences in anxiety were associated with the strength of coupling between medial thalamus and mPFC, which was furthermore related to activity in the amygdala. These results indicate not only that there is a distinct signature for the encoding of a painful experience in humans, but also that this encoding process involves a strong affective component. SIGNIFICANCE STATEMENT To convert the sensation of pain into a briefly maintainable construct is essential to guide human behavior and avoid dangerous situations. Although this working memory encoding process is implicitly contained in the majority of studies, the underlying neural mechanisms remain unclear. Using fMRI in a delayed-discrimination task, we found that the

  5. Neuroanatomical Abnormalities in Violent Individuals with and without a Diagnosis of Schizophrenia.

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    Del Bene, Victor A; Foxe, John J; Ross, Lars A; Krakowski, Menahem I; Czobor, Pal; De Sanctis, Pierfilippo

    2016-01-01

    Several structural brain abnormalities have been associated with aggression in patients with schizophrenia. However, little is known about shared and distinct abnormalities underlying aggression in these subjects and non-psychotic violent individuals. We applied a region-of-interest volumetric analysis of the amygdala, hippocampus, and thalamus bilaterally, as well as whole brain and ventricular volumes to investigate violent (n = 37) and non-violent chronic patients (n = 26) with schizophrenia, non-psychotic violent (n = 24) as well as healthy control subjects (n = 24). Shared and distinct volumetric abnormalities were probed by analysis of variance with the factors violence (non-violent versus violent) and diagnosis (non-psychotic versus psychotic), adjusted for substance abuse, age, academic achievement and negative psychotic symptoms. Patients showed elevated vCSF volume, smaller left hippocampus and smaller left thalamus volumes. This was particularly the case for non-violent individuals diagnosed with schizophrenia. Furthermore, patients had reduction in right thalamus size. With regard to left amygdala, we found an interaction between violence and diagnosis. More specifically, we report a double dissociation with smaller amygdala size linked to violence in non-psychotic individuals, while for psychotic patients smaller size was linked to non-violence. Importantly, the double dissociation appeared to be mostly driven by substance abuse. Overall, we found widespread morphometric abnormalities in subcortical regions in schizophrenia. No evidence for shared volumetric abnormalities in individuals with a history of violence was found. Finally, left amygdala abnormalities in non-psychotic violent individuals were largely accounted for by substance abuse. This might be an indication that the association between amygdala reduction and violence is mediated by substance abuse. Our results indicate the importance of structural abnormalities in aggressive individuals.

  6. Neuroanatomical Abnormalities in Violent Individuals with and without a Diagnosis of Schizophrenia.

    Directory of Open Access Journals (Sweden)

    Victor A Del Bene

    Full Text Available Several structural brain abnormalities have been associated with aggression in patients with schizophrenia. However, little is known about shared and distinct abnormalities underlying aggression in these subjects and non-psychotic violent individuals. We applied a region-of-interest volumetric analysis of the amygdala, hippocampus, and thalamus bilaterally, as well as whole brain and ventricular volumes to investigate violent (n = 37 and non-violent chronic patients (n = 26 with schizophrenia, non-psychotic violent (n = 24 as well as healthy control subjects (n = 24. Shared and distinct volumetric abnormalities were probed by analysis of variance with the factors violence (non-violent versus violent and diagnosis (non-psychotic versus psychotic, adjusted for substance abuse, age, academic achievement and negative psychotic symptoms. Patients showed elevated vCSF volume, smaller left hippocampus and smaller left thalamus volumes. This was particularly the case for non-violent individuals diagnosed with schizophrenia. Furthermore, patients had reduction in right thalamus size. With regard to left amygdala, we found an interaction between violence and diagnosis. More specifically, we report a double dissociation with smaller amygdala size linked to violence in non-psychotic individuals, while for psychotic patients smaller size was linked to non-violence. Importantly, the double dissociation appeared to be mostly driven by substance abuse. Overall, we found widespread morphometric abnormalities in subcortical regions in schizophrenia. No evidence for shared volumetric abnormalities in individuals with a history of violence was found. Finally, left amygdala abnormalities in non-psychotic violent individuals were largely accounted for by substance abuse. This might be an indication that the association between amygdala reduction and violence is mediated by substance abuse. Our results indicate the importance of structural abnormalities in aggressive

  7. Voxelwise meta-ananlysis of gray matter anomalies in progressive supranuclear palsy and Parkinson’s disease using anatomic likelihood estimation

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    Huifang eShang

    2014-02-01

    Full Text Available Numerous voxel-based morphometry (VBM studies on gray matter (GM of patients with progressive supranuclear palsy (PSP and Parkinson’s disease (PD have been conducted separately. Identifying the different neuroanatomical changes in GM resulting from PSP and PD through meta-analysis will aid the differential diagnosis of PSP and PD. In this study, a systematic review of VBM studies of patients with PSP and PD relative to healthy controls (HC in the Embase and PubMed databases from January 1995 to April 2013 was conducted. The anatomical distribution of the coordinates of GM differences was meta-analyzed using anatomical likelihood estimation. Separate maps of GM changes were constructed and subtraction meta-analysis was performed to explore the differences in GM abnormalities between PSP and PD. Nine PSP studies and 24 PD studies were included. GM reductions were present in the bilateral thalamus, basal ganglia, midbrain, insular cortex and inferior frontal gyrus, and left precentral gyrus and anterior cingulate gyrus in PSP. Atrophy of GM was concentrated in the bilateral middle and inferior frontal gyrus, precuneus, left precentral gyrus, middle temporal gyrus, right superior parietal lobule, and right cuneus in PD. Subtraction meta-analysis indicated that GM volume was lesser in the bilateral midbrain, thalamus, and insula in PSP compared with that in PD. Our meta-analysis indicated that PSP and PD shared a similar distribution of neuroanatomical changes in the frontal lobe, including inferior frontal gyrus and precentral gyrus, and that atrophy of the midbrain, thalamus, and insula are neuroanatomical markers for differentiating PSP from PD.

  8. Disrupted thalamic resting-state functional connectivity in patients with minimal hepatic encephalopathy

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    Qi, Rongfeng [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China); Zhang, Long Jiang, E-mail: kevinzhanglongjiang@yahoo.com.cn [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China); Zhong, Jianhui [Department of Biomedical Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zhang, Zhiqiang; Ni, Ling; Zheng, Gang [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China); Lu, Guang Ming, E-mail: cjr.luguangming@vip.163.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China)

    2013-05-15

    Background and purpose: Little is known about the role of thalamus in the pathophysiology of minimal hepatic encephalopathy (MHE). The purpose of this study was to investigate whether the thalamic functional connectivity was disrupted in cirrhotic patients with MHE by using resting-state functional magnetic resonance imaging (rs-fMRI). Materials and Methods: Twenty seven MHE patients and twenty seven age- and gender- matched healthy controls participated in the rs-fMRI scans. The functional connectivity of 11 thalamic nuclei were characterized by using a standard seed-based whole-brain correlation method and compared between MHE patients and healthy controls. Pearson correlation analysis was performed between the thalamic functional connectivity and venous blood ammonia levels/neuropsychological tests scores of patients. Results: The ventral anterior nucleus (VAN) and the ventral posterior medial nucleus (VPMN) in each side of thalamus showed abnormal functional connectivities in MHE. Compared with healthy controls, MHE patients demonstrated significant decreased functional connectivity between the right/left VAN and the bilateral putamen/pallidum, inferior frontal gyri, insula, supplementary motor area, right middle frontal gyrus, medial frontal gyrus. In addition, MHE patients showed significantly decreased functional connectivity with the right/left VPMN in the bilateral middle temporal gyri (MTG), temporal lobe, and right superior temporal gyrus. The venous blood ammonia levels of MHE patients negatively correlated with the functional connectivity between the VAN and the insula. Number connecting test scores showed negative correlation with the functional connectivity between the VAN and the insula, and between the VPMN and the MTG. Conclusion: MHE patients had disrupted thalamic functional connectivity, which mainly located in the bilateral ventral anterior nuclei and ventral posterior medial nuclei. The decreased connectivity between thalamus and many

  9. Altered spontaneous brain activity in patients with acute spinal cord injury revealed by resting-state functional MRI.

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    Ling Zhu

    Full Text Available Previous neuroimaging studies have provided evidence of structural and functional reorganization of brain in patients with chronic spinal cord injury (SCI. However, it remains unknown whether the spontaneous brain activity changes in acute SCI. In this study, we investigated intrinsic brain activity in acute SCI patients using a regional homogeneity (ReHo analysis based on resting-state functional magnetic resonance imaging.A total of 15 patients with acute SCI and 16 healthy controls participated in the study. The ReHo value was used to evaluate spontaneous brain activity, and voxel-wise comparisons of ReHo were performed to identify brain regions with altered spontaneous brain activity between groups. We also assessed the associations between ReHo and the clinical scores in brain regions showing changed spontaneous brain activity.Compared with the controls, the acute SCI patients showed decreased ReHo in the bilateral primary motor cortex/primary somatosensory cortex, bilateral supplementary motor area/dorsal lateral prefrontal cortex, right inferior frontal gyrus, bilateral dorsal anterior cingulate cortex and bilateral caudate; and increased ReHo in bilateral precuneus, the left inferior parietal lobe, the left brainstem/hippocampus, the left cingulate motor area, bilateral insula, bilateral thalamus and bilateral cerebellum. The average ReHo values of the left thalamus and right insula were negatively correlated with the international standards for the neurological classification of spinal cord injury motor scores.Our findings indicate that acute distant neuronal damage has an immediate impact on spontaneous brain activity. In acute SCI patients, the ReHo was prominently altered in brain regions involved in motor execution and cognitive control, default mode network, and which are associated with sensorimotor compensatory reorganization. Abnormal ReHo values in the left thalamus and right insula could serve as potential biomarkers for

  10. Reduced metabolism in brain "control networks" following cocaine-cues exposure in female cocaine abusers.

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    Nora D Volkow

    2011-02-01

    Full Text Available Gender differences in vulnerability for cocaine addiction have been reported. Though the mechanisms are not understood, here we hypothesize that gender differences in reactivity to conditioned-cues, which contributes to relapse, are involved.To test this we compared brain metabolism (using PET and ¹⁸FDG between female (n = 10 and male (n = 16 active cocaine abusers when they watched a neutral video (nature scenes versus a cocaine-cues video.Self-reports of craving increased with the cocaine-cue video but responses did not differ between genders. In contrast, changes in whole brain metabolism with cocaine-cues differed by gender (p<0.05; females significantly decreased metabolism (-8.6%±10 whereas males tended to increase it (+5.5%±18. SPM analysis (Cocaine-cues vs Neutral in females revealed decreases in frontal, cingulate and parietal cortices, thalamus and midbrain (p<0.001 whereas males showed increases in right inferior frontal gyrus (BA 44/45 (only at p<0.005. The gender-cue interaction showed greater decrements with Cocaine-cues in females than males (p<0.001 in frontal (BA 8, 9, 10, anterior cingulate (BA 24, 32, posterior cingulate (BA 23, 31, inferior parietal (BA 40 and thalamus (dorsomedial nucleus.Females showed greater brain reactivity to cocaine-cues than males but no differences in craving, suggesting that there may be gender differences in response to cues that are not linked with craving but could affect subsequent drug use. Specifically deactivation of brain regions from "control networks" (prefrontal, cingulate, inferior parietal, thalamus in females could increase their vulnerability to relapse since it would interfere with executive function (cognitive inhibition. This highlights the importance of gender tailored interventions for cocaine addiction.

  11. Detecting a dexmedetomidine-evoked reduction of noradrenaline release in the human brain with the alpha2C-adrenoceptor PET ligand [11C]ORM-13070.

    Science.gov (United States)

    Lehto, Jussi; Scheinin, Annalotta; Johansson, Jarkko; Marjamäki, Päivi; Arponen, Eveliina; Scheinin, Harry; Scheinin, Mika

    2016-02-01

    PET imaging can for some neurotransmitters be used to measure synaptic neurotransmitter concentrations. The objective of this study was to test whether the receptor binding of the α2C -AR antagonist PET tracer [(11)C]ORM-13070 would increase in response to reductions in synaptic noradrenaline, evoked by dexmedetomidine as a sympatholytic drug challenge. Six subjects underwent a control PET scan and two dexmedetomidine PET scans. Dexmedetomidine was infused with target plasma concentrations of 0.6 and 0.2 ng/ml. Tracer binding was measured by voxel-based analysis of bound per free (B/F) images. ROI-based analysis was performed in the dorsal striatum and in the thalamus. Vital signs and drug concentrations in plasma were measured and the sedative effect was estimated with the visual analog scale. In the voxel-based analysis, dexmedetomidine administration was associated with a tendency to increased B/F tracer in the right thalamus (mean, +17%, P = 0.14, and +19%, P = 0.05, with the low and high dose, respectively). Tracer binding in the dorsal striatum was unaffected by dexmedetomidine. A cluster with significantly increased B/F tracer (+42%, P = 0.01) was seen in the right superior temporal gyrus with low-dose dexmedetomidine, but not after the high dose. Brain uptake of [(11)C]ORM-13070 has previously been shown to be reduced in conditions of increased synaptic noradrenaline concentrations. In this study, tracer binding in the thalamus tended to increase in accordance with reduced activity of noradrenergic projections from the locus coeruleus, but statistical significance was not reached. © 2015 Wiley Periodicals, Inc.

  12. Telencephalic connections in the Pacific hagfish (Eptatretus stouti), with special reference to the thalamopallial system.

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    Wicht, H; Northcutt, R G

    1998-06-01

    The pallium of hagfishes (myxinoids) is unique: It consists of a superficial "cortical" mantle of gray matter which is subdivided into several layers and fields, but it is not clear whether or how these subdivisions can be compared to those of other craniates, i.e., lampreys and gnathostomes. The pallium of hagfishes receives extensive secondary olfactory projections (Wicht and Northcutt [1993] J. Comp. Neurol. 337:529-542), but there are no experimental data on its nonolfactory connections. We therefore investigated the pallial and dorsal thalamic connections of the Pacific hagfish. Injections of tracers into the pallium labeled many cells bilaterally in the olfactory bulbs. Other pallial afferents arise from the contralateral pallium, the dorsal thalamic nuclei, the preoptic region, and the posterior tubercular nuclei. Descending pallial efferents reach the preoptic region, the dorsal thalamus, and the mesencephalic tectum but not the motor or premotor centers of the brainstem. Injections of tracers into the dorsal thalamus confirmed the presence of reciprocal thalamopallial connections. In addition, these injections revealed that there is no "preferred" pallial target for the ascending thalamic fibers; instead, ascending thalamic and secondary olfactory projections overlap throughout the pallium. The mesencephalic tectum and tegmentum, which receive afferents from a variety of sensory sources, are interconnected with the dorsal thalamus; thus, ascending nonolfactory sensory information may reach myxinoid pallia via a tectal-thalamic-telencephalic route. A comparative analysis of pallial organization reveals that the subdivisions of the pallium in gnathostomes (i.e., medial, dorsal, and lateral pallia) cannot be recognized with certainty in hagfishes.

  13. Role of thalamic diffusion for disease differentiation between multiple sclerosis and ischemic cerebral small vessel disease

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    Oeztoprak, Bilge; Oeztoprak, Ibrahim; Salk, Ismail [Cumhuriyet University School of Medicine, Department of Radiology, Sivas (Turkey); Topalkara, Kamil [Bayindir Hospital, Department of Neurology, Ankara (Turkey); Erkoc, Mustafa F. [Bozok University School of Medicine, Department of Radiology, Yozgat (Turkey)

    2015-04-01

    Cerebral small vessel disease (CSVD) and multiple sclerosis (MS) both harbor multiple, T2-hyperintense white matter lesions on conventional magnetic resonance imaging (MRI).We aimed to determine the microstructural changes via diffusion-weighted imaging (DWI) in normal appearing thalami. We hypothesized that the apparent diffusion coefficient (ADC) values would be different in CSVD and MS, since the extent of arterial involvement is different in these two diseases. DWI was performed for 50 patients with CSVD and 35 patients with MS along with gender- and age-matched controls whose conventional MRI revealed normal findings. DWI was done with 1.5 Tesla MR devices using echo planar imaging (EPI) for b = 0, 1000 s/mm{sup 2}. ADC values were obtained from the thalami which appeared normal on T2-weighted and FLAIR images. Standard oval regions of interest (ROIs) of 0.5 cm{sup 2} which were oriented parallel to the long axis of the thalamus were used for this purpose. The mean ADC value of the thalamus was (0.99 ± 0.16) x 10{sup -3} mm{sup 2}/s in patients with CSVD, whereas the mean ADC value was (0.78 ± 0.06) x 10{sup -3} mm{sup 2}/s in the control group. The mean ADC value was significantly higher in patients with CSVD compared to the controls (p < 0.001). The mean ADC values of the thalamus were (0.78 ± 0.08) x 10{sup -3} mm{sup 2}/s in MS patients, and (0.75 ± 0.08) x 10{sup -3} mm{sup 2}/s in the control group, which are not significantly different (p > 0.05). Our study revealed a difference in the diffusion of the thalami between CSVD and MS. DWI may aid in the radiological disease differentiation. (orig.)

  14. Cerebral blood flow SPET in transient global amnesia with automated ROI analysis by 3DSRT

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    Takeuchi, Ryo [Division of Nuclear Medicine, Nishi-Kobe Medical Center, Kohjidai 5-7-1, 651-2273, Nishi-ku, Kobe-City, Hyogo (Japan); Matsuda, Hiroshi [Department of Radiology, National Center Hospital for Mental, Nervous and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo (Japan); Yoshioka, Katsunori [Daiichi Radioisotope Laboratories, Ltd., Tokyo (Japan); Yonekura, Yoshiharu [Biomedical Imaging Research Center, University of Fukui, Fukui (Japan)

    2004-04-01

    The aim of this study was to determine the areas involved in episodes of transient global amnesia (TGA) by calculation of cerebral blood flow (CBF) using 3DSRT, fully automated ROI analysis software which we recently developed. Technetium-99m l,l-ethyl cysteinate dimer single-photon emission tomography ({sup 99m}Tc-ECD SPET) was performed during and after TGA attacks on eight patients (four men and four women; mean study interval, 34 days). The SPET images were anatomically standardized using SPM99 followed by quantification of 318 constant ROIs, grouped into 12 segments (callosomarginal, precentral, central, parietal, angular, temporal, posterior cerebral, pericallosal, lenticular nucleus, thalamus, hippocampus and cerebellum), in each hemisphere to calculate segmental CBF (sCBF) as the area-weighted mean value for each of the respective 12 segments based on the regional CBF in each ROI. Correlation of the intra- and post-episodic sCBF of each of the 12 segments of the eight patients was estimated by scatter-plot graphical analysis and Pearson's correlation test with Fisher's Z-transformation. For the control, {sup 99m}Tc-ECD SPET was performed on eight subjects (three men and five women) and repeated within 1 month; the correlation between the first and second sCBF values of each of the 12 segments was evaluated in the same way as for patients with TGA. Excellent reproducibility between the two sCBF values was found in all 12 segments of the control subjects. However, a significant correlation between intra- and post-episodic sCBF was not shown in the thalamus or angular segments of TGA patients. The present study was preliminary, but at least suggested that thalamus and angular regions are closely involved in the symptoms of TGA. (orig.)

  15. Effect of dimethyl fumarate on gray and white matter pathology in subjects with relapsing multiple sclerosis: a longitudinal study.

    Science.gov (United States)

    Zivadinov, R; Hagemeier, J; Bergsland, N; Tavazzi, E; Weinstock-Guttman, B

    2018-03-01

    Dimethyl fumarate (DMF) is an oral treatment for relapsing-remitting multiple sclerosis (MS) with anti-inflammatory and possible neuroprotective properties. Its effect on white matter and gray matter pathology is still not fully understood. The aim of the study was to characterize the effect of DMF on normal-appearing white matter (NAWM) and thalamic pathology longitudinally. In this observational, longitudinal, 24-month magnetic resonance imaging study, 75 patients with relapsing-remitting MS treated with DMF and 40 age- and sex-matched healthy individuals were enrolled. Regional diffusion tensor imaging metrics and tract-based spatial statistics analyses were used to assess differences between groups. Mean diffusivity, axial diffusivity, radial diffusivity and fractional anisotropy were measured in the thalamus and NAWM. Baseline differences and changes over time were evaluated within and between study groups. At baseline, patients with MS showed significantly increased diffusivity and decreased fractional anisotropy in the thalamus (P < 0.001 for mean diffusivity, axial diffusivity and radial diffusivity) and NAWM (all P < 0.016) compared with healthy individuals. No significant within-group difference was found in diffusion tensor imaging measures over 24 months in either group. Healthy individuals showed a significantly greater rate of increased diffusivity parameters in the thalamus and NAWM compared with patients with MS, over 24 months (P < 0.05). The lack of changes in diffusion tensor imaging metrics in patients with MS over 24 months possibly indicates a neuroprotective role of DMF. These findings provide additional evidence of the beneficial effect of DMF on MS-related pathology. © 2018 EAN.

  16. Thalamocortical relationship in epileptic patients with generalized spike and wave discharges — A multimodal neuroimaging study

    Directory of Open Access Journals (Sweden)

    Clara Huishi Zhang

    2015-01-01

    Full Text Available Unlike focal or partial epilepsy, which has a confined range of influence, idiopathic generalized epilepsy (IGE often affects the whole or a larger portion of the brain without obvious, known cause. It is important to understand the underlying network which generates epileptic activity and through which epileptic activity propagates. The aim of the present study was to investigate the thalamocortical relationship using non-invasive imaging modalities in a group of IGE patients. We specifically investigated the roles of the mediodorsal nuclei in the thalami and the medial frontal cortex in generating and spreading IGE activities. We hypothesized that the connectivity between these two structures is key in understanding the generation and propagation of epileptic activity in brains affected by IGE. Using three imaging techniques of EEG, fMRI and EEG-informed fMRI, we identified important players in generation and propagation of generalized spike-and-wave discharges (GSWDs. EEG-informed fMRI suggested multiple regions including the medial frontal area near to the anterior cingulate cortex, mediodorsal nuclei of the thalamus, caudate nucleus among others that related to the GSWDs. The subsequent seed-based fMRI analysis revealed a reciprocal cortical and bi-thalamic functional connection. Through EEG-based Granger Causality analysis using (DTF and adaptive DTF, within the reciprocal thalamocortical circuitry, thalamus seems to serve as a stronger source in driving cortical activity from initiation to the propagation of a GSWD. Such connectivity change starts before the GSWDs and continues till the end of the slow wave discharge. Thalamus, especially the mediodorsal nuclei, may serve as potential targets for deep brain stimulation to provide more effective treatment options for patients with drug-resistant generalized epilepsy.

  17. Global and regional annual brain volume loss rates in physiological aging.

    Science.gov (United States)

    Schippling, Sven; Ostwaldt, Ann-Christin; Suppa, Per; Spies, Lothar; Manogaran, Praveena; Gocke, Carola; Huppertz, Hans-Jürgen; Opfer, Roland

    2017-03-01

    The objective is to estimate average global and regional percentage brain volume loss per year (BVL/year) of the physiologically ageing brain. Two independent, cross-sectional single scanner cohorts of healthy subjects were included. The first cohort (n = 248) was acquired at the Medical Prevention Center (MPCH) in Hamburg, Germany. The second cohort (n = 316) was taken from the Open Access Series of Imaging Studies (OASIS). Brain parenchyma (BP), grey matter (GM), white matter (WM), corpus callosum (CC), and thalamus volumes were calculated. A non-parametric technique was applied to fit the resulting age-volume data. For each age, the BVL/year was derived from the age-volume curves. The resulting BVL/year curves were compared between the two cohorts. For the MPCH cohort, the BVL/year curve of the BP was an increasing function starting from 0.20% at the age of 35 years increasing to 0.52% at 70 years (corresponding values for GM ranged from 0.32 to 0.55%, WM from 0.02 to 0.47%, CC from 0.07 to 0.48%, and thalamus from 0.25 to 0.54%). Mean absolute difference between BVL/year trajectories across the age range of 35-70 years was 0.02% for BP, 0.04% for GM, 0.04% for WM, 0.11% for CC, and 0.02% for the thalamus. Physiological BVL/year rates were remarkably consistent between the two cohorts and independent from the scanner applied. Average BVL/year was clearly age and compartment dependent. These results need to be taken into account when defining cut-off values for pathological annual brain volume loss in disease models, such as multiple sclerosis.

  18. Cerebral activation associated with visually evoked sexual arousal in the limbic system: functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Eun, Sung Jong; Kong, Gwang Woo; Kim, Hyung Joong; Seo, Jeong Jin; Kang, Heoung Keun; Cho, Ki Hyun; Yoon, Ka Hyun [School of Medicine, Chonnam National Univ., Kwangju (Korea, Republic of); Kim, Kyung Yo [Wonkwang Univ., Iksan (Korea, Republic of)

    2004-08-01

    To identify the brain centers associated with visually evoked sexual arousal in the human brain, and to investigate the neural mechanism for sexual arousal using functional MRI (fMRI). A total of 20 sexually potent volunteers consisting of 10 males (mean age: 24) and 10 females (mean age: 23) underwent fMRI on a 1.5T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 slices (10 mm slice thickness) parallel to the AC-PC (anterior commissure and posterior commissure) line, giving a total of 511 MR images. The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 4-minute stimulation by an erotic video film, and concluded with a 2-minute rest. The brain activation maps and their quantification were analyzed by the statistical parametric mapping (SPM 99) program. The brain activation regions associated with visual sexual arousal in the limbic system are the posterior cingulate gyrus, parahippocampal gyrus, hypothalamus, medial cingulate gyrus, thalamus, amygdala, anterior cingulate gyrus, insula, hippocampus, caudate nucleus, globus pallidus and putamen. Especially, the parahippocampal gyrus, cingulate gyrus, thalamus and hypothalamus were highly activated in comparison with other areas. The overall activities of the limbic lobe, diencephalon, and basal ganglia were 11.8%, 10.5%, and 3.4%, respectively. In the correlation test between brain activity and sexual arousal, the hypothalamus and thalamus showed positive correlation, but the other brain areas showed no correlation. The fMRI is useful to quantitatively evaluate the cerebral activation associated with visually evoked, sexual arousal in the human brain. This result may be helpful by providing clinically valuable information on sexual disorder in humans as well as by increasing the understanding of the neuroanatomical correlates of sexual arousal.

  19. Correlation between changes in regional cerebral blood flow and pain relief in complex regional pain syndrome type 1.

    Science.gov (United States)

    Wu, Ching-Tang; Fan, Yu-Ming; Sun, Chen-Ming; Borel, Cecil O; Yeh, Chun-Chang; Yang, Chih-Ping; Wong, Chih-Shung

    2006-06-01

    Analyzing changes in regional cerebral blood flow (rCBF) with SPECT in complex regional pain syndrome type 1 (CRPS 1), formerly known as reflex sympathetic dystrophy, is an optimal method for evaluating effective pain relief. We attempted to investigate the correlation of changes in rCBF with pain relief during treatments of sympathetic blockade and multimodal epidural pain control. We describe a patient with severe CRPS 1 in whom conventional treatment failed to relieve the pain. Combined repeated lumbar sympathetic blocks and long-term epidural morphine, bupivacaine, and ketamine administration provided satisfactory pain relief and functional activity recovery. Six normal control subjects having one Tc-99m HMPAO scan each and the patient with CRPS having 3 Tc-99m HMPAO scans (once before treatment and twice at 4 months and 6 months after treatment, respectively). The patient with CRPS showed lower rCBF than normal controls in the left thalamus and higher rCBF than normal controls in the right parietal lobe and left frontal lobe. After subsequent treatment, the subtraction images showed increased rCBF in the left thalamus and decreased rCBF in the right parietal and left frontal lobes. Tc-99m HMPAO SPECT showed a relationship of rCBF in the thalamus, parietal lobe, and frontal lobe with pain relief. rCBF alterations may provide an indicator for the quality of pain management for neuropathic pains. Subtraction analysis between pre- and posttreatment, by using statistical parametric mapping (version 2), can be used as an objective indicator for the effectiveness of therapy.

  20. Signal intensity at unenhanced T1-weighted magnetic resonance in the globus pallidus and dentate nucleus after serial administrations of a macrocyclic gadolinium-based contrast agent in children.

    Science.gov (United States)

    Rossi Espagnet, Maria Camilla; Bernardi, Bruno; Pasquini, Luca; Figà-Talamanca, Lorenzo; Tomà, Paolo; Napolitano, Antonio

    2017-09-01

    Few studies have been conducted on the relations between T1-weighted signal intensity changes in the pediatric brain following gadolinium-based contrast agent (GBCA) exposure. The purpose of this study is to investigate the effect of multiple administrations of a macrocyclic GBCA on signal intensity in the globus pallidus and dentate nucleus of the pediatric brain on unenhanced T1-weighted MR images. This retrospective study included 50 patients, mean age: 8 years (standard deviation: 4.8 years), with normal renal function exposed to ≥6 administrations of the same macrocyclic GBCA (gadoterate meglumine) and a control group of 59 age-matched GBCA-naïve patients. The globus pallidus-to-thalamus signal intensity ratio and dentate nucleus-to-pons signal intensity ratio were calculated from unenhanced T1-weighted images for both patients and controls. A mixed linear model was used to evaluate the effects on signal intensity ratios of the number of GBCA administrations, the time interval between administrations, age, radiotherapy and chemotherapy. T-test analyses were performed to compare signal intensity ratio differences between successive administrations and baseline MR signal intensity ratios in patients compared to controls. P-values were considered significant if <0.05. A significant effect of the number of GBCA administrations on relative signal intensities globus pallidus-to-thalamus (F[8]=3.09; P=0.002) and dentate nucleus-to-pons (F[8]=2.36; P=0.021) was found. The relative signal intensities were higher at last MR examination than at baseline (P<0.001). Quantitative analysis evaluation of globus pallidus:thalamus and dentate nucleus:pons of the pediatric brain demonstrated an increase after serial administrations of macrocyclic GBCA. Further research is necessary to fully understand GBCA pharmacokinetic in children.

  1. Thalamic volume as a biomarker for disorders of consciousness

    Science.gov (United States)

    Rubeaux, Mathieu; Mahalingam, Jamuna Jayashri; Gomez, Francisco; Nelson, Marvin; Vanhaudenhuyse, Audrey; Bruno, Marie-Aurélie; Gosseries, Olivia; Laureys, Steven; Soddu, Andrea; Lepore, Natasha

    2015-01-01

    Disorders of consciousness (DOC) may be characterized by the degree at which consciousness is impaired, and include for example vegetative state (VS) and minimally conscious state (MCS) patients. Using a reliable marker as a measure of the level of consciousness in such patients is of utmost necessity and importance for their appropriate diagnosis and prognosis. Identification of VS and MCS states based on their behaviors sometimes leads to incorrect inferences due to the influence of a range of factors like motor impairment, fluctuating arousal levels and rapidly habituating responses to name a few.1 The extent of damage in the thalamus, a structure known for its role in arousal regulation, may provide an imaging biomarker to better differentiate between VS and MCS. In this study, we manually segmented the thalamus from T1-weighted brain MRI images in a large cohort of 19 VS and 23 MCS subjects that were examined using the French version of the Coma Recovery Scale Revised (CRS-R).2 This scale is the most trustworthy behavioural diagnosis tool3 for patients with DOC available. The aim was to determine whether a relationship between thalamus volume and consciousness level exists. Results show that total thalamic volume tends to decrease over time after a severe brain injury. Moreover, for subjects in chronic state, the thalamic volume seems to differ with respect to the degree of consciousness that was diagnosed. Finally, for these same chronic patients, the total thalamic volume is varying linearly as a function of the CRS-R score obtained, indicating that thalamic volume may be used as a biomarker to measure the level of consciousness.

  2. Metabolic patterns in prion diseases: an FDG PET voxel-based analysis

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, Elena; Dominguez-Prado, Ines; Jesus Ribelles, Maria; Arbizu, Javier [Clinica Universidad de Navarra, Nuclear Medicine Department, Pamplona (Spain); Riverol, Mario; Ortega-Cubero, Sara; Rosario Luquin, Maria; Castro, Purificacion de [Clinica Universidad de Navarra, Neurology Department, Pamplona (Spain)

    2015-09-15

    Clinical diagnosis of human prion diseases can be challenging since symptoms are common to other disorders associated with rapidly progressive dementia. In this context, {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET) might be a useful complementary tool. The aim of this study was to determine the metabolic pattern in human prion diseases, particularly sporadic Creutzfeldt-Jakob disease (sCJD), the new variant of Creutzfeldt-Jakob disease (vCJD) and fatal familial insomnia (FFI). We retrospectively studied 17 patients with a definitive, probable or possible prion disease who underwent FDG PET in our institution. Of these patients, 12 were diagnosed as sCJD (9 definitive, 2 probable and 1 possible), 1 was diagnosed as definitive vCJD and 4 were diagnosed as definitive FFI. The hypometabolic pattern of each individual and comparisons across the groups of subjects (control subjects, sCJD and FFI) were evaluated using a voxel-based analysis. The sCJD group exhibited a pattern of hypometabolism that affected both subcortical (bilateral caudate, thalamus) and cortical (frontal cortex) structures, while the FFI group only presented a slight hypometabolism in the thalamus. Individual analysis demonstrated a considerable variability of metabolic patterns among patients, with the thalamus and basal ganglia the most frequently affected areas, combined in some cases with frontal and temporal hypometabolism. Patients with a prion disease exhibit a characteristic pattern of brain metabolism presentation in FDG PET imaging. Consequently, in patients with rapidly progressive cognitive impairment, the detection of these patterns in the FDG PET study could orient the diagnosis to a prion disease. (orig.)

  3. Finding prefrontal cortex in the rat.

    Science.gov (United States)

    Leonard, Christiana M

    2016-08-15

    The prefrontal cortex of the rat. I. Cortical projection of the mediodorsal nucleus. II. Efferent connections The cortical projection field of the mediodorsal nucleus of the thalamus (MD) was identified in the rat using the Fink-Heimer silver technique for tracing degenerating fibers. Small stereotaxic lesions confined to MD were followed by terminal degeneration in the dorsal bank of the rhinal sulcus (sulcal cortex) and the medial wall of the hemisphere anterior and dorsal to the genu of the corpus callosum (medial cortex). No degenerating fibers were traced to the convexity of the hemisphere. The cortical formation receiving a projection from MD is of a relatively undifferentiated type which had been previously classified as juxtallocortex. A study of the efferent fiber connections of the rat׳s MD-projection cortex demonstrated some similarities to those of monkey prefrontal cortex. A substantial projection to the pretectal area and deep layers of the superior colliculus originates in medial cortex, a connection previously reported for caudal prefrontal (area 8) cortex in the monkey. Sulcal cortex projects to basal olfactory structures and lateral hypothalamus, as does orbital frontal cortex in the monkey. The rat׳s MD-projection cortex differs from that in the monkey in that it lacks a granular layer and appears to have no prominent direct associations with temporal and juxtahippocampal areas. Furthermore, retrograde degeneration does not appear in the rat thalamus after damage to MD-projection areas, suggesting that the striatum or thalamus receives a proportionally larger share of the MD-projection in this animal than it does in the monkey. Comparative behavioral investigations are in progress to investigate functional differences between granular prefrontal cortex in the primate and the relatively primitive MD-projection cortex in the rat. © 1969. This article is part of a Special Issue entitled SI:50th Anniversary Issue. Copyright © 2016 Elsevier B

  4. Quantification of cerebral nicotinic acetylcholine receptors by PET using 2-F-18 fluoro-A-85380 and the multi-injection approach

    Energy Technology Data Exchange (ETDEWEB)

    Gallezot, J.D.; Bottlaender, M.A.; Delforge, J.; Valette, H.; Saba, W.; Dolle, F.; Coulon, C.M.; Ottaviani, M.P.; Hinnen, F.; Syrota, A. [CEA, DSV, Serv Hosp Frederic Joliot, I2BM, F-91401 Orsay (France); Gregoire, M.C. [CEA, Serv Hosp Frederic Joliot, CNRS, URA 2210, F-91401 Orsay (France)

    2008-07-01

    The multi-injection approach was used to study in vivo interactions between {alpha}4{beta}2 nicotinic acetylcholine receptors and 2-[{sup 18}F] fluoro-A-85380 in baboons. The ligand kinetics was modeled by the usual nonlinear compartment model composed of three compartments (arterial plasma, free and specifically bound ligand in tissue). Arterial blood samples were collected to generate a metabolite-corrected plasma input function. The experimental protocol, which consisted of three injections of labeled or unlabeled ligand, was aiming at identifying all parameters in one experiment. Various parameters, including B'max (the binding sites density) and K{sub d}V{sub R} (the apparent in vivo affinity of 2-[{sup 18}F]fluoro-A-85380) could then be estimated in thalamus and in several receptor-poor regions. B'max estimate was 3.0 {+-} 0.3 pmol/ml in thalamus, and ranged from 0.25 to 1.58 pmol/ml in extra-thalamic regions. Although K{sub d}V{sub R} could be precisely estimated, the association and dissociation rate constants kon/V{sub R} and koff could not be identified separately. A second protocol was then used to estimate koff more precisely in the thalamus. Having estimated all model parameters, we performed simulations of 2-[{sup 18}F]fluoro-A-85380 kinetics to test equilibrium hypotheses underlying simplified approaches. These showed that a pseudo-equilibrium is quickly reached between the free and bound compartments, a favorable situation to apply Logan graphical analysis. In contrast, the pseudo-equilibrium between the plasma and free compartments is only reached after several hours. The ratio of radioligand concentration in these two compartments then overestimates the true equilibrium value, an unfavorable situation to estimate distribution volumes from late images after a bolus injection. (authors)

  5. Normal cerebral FDG uptake during childhood

    Energy Technology Data Exchange (ETDEWEB)

    London, Kevin [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Discipline of Paediatrics and Child Health, Sydney Medical School, Sydney, NSW (Australia); Howman-Giles, Robert [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Disciplines of Imaging and Paediatrics and Child Health, Sydney Medical School, Sydney, NSW (Australia)

    2014-04-15

    Current understanding of cerebral FDG uptake during childhood originates from a small number of studies in patients with neurological abnormalities. Our aim was to describe cerebral FDG uptake in a dataset of FDG PET scans in children more likely to represent a normal population. We reviewed cerebral FDG PET scans in children up to 16 years of age with suspected/proven extracranial malignancies and the following exclusions: central nervous system metastases, previous malignancies, previous chemotherapy or radiotherapy, development of cerebral metastases during therapy, neurological conditions, taking antiepileptic medication or medications likely to interfere with cerebral metabolism, and general anaesthesia within 24 h. White matter, basal ganglia, thalamus and the cerebellar cortex were analysed using regional SUV{sub max}, and the cerebral cortex, basal ganglia, thalamus and cerebellum were analysed using a regional relative uptake analysis in comparison to maximal cortical uptake. Scans from 30 patients (age range 11 months to 16 years, mean age 10 years 5 months) were included. All regions showed increasing SUV{sub max} with age. The parietal, occipital, lateral temporal and medial temporal lobes showed lower rates of increasing FDG uptake causing changing patterns of regional FDG uptake during childhood. The cortical regions showing the most intense uptake in early childhood were the parietal and occipital lobes. At approximately 7 years of age these regions had relatively less uptake than the frontal lobes and at approximately 10 years of age these regions had relatively less uptake than the thalamus. Relative FDG uptake in the brain has not reached an adult pattern by 1 year of age, but continues to change up to 16 years of age. The changing pattern is due to different regional rates of increasing cortical FDG uptake, which is less rapid in the parietal, occipital and temporal lobes than in the frontal lobes. (orig.)

  6. Thalamocortical functional connectivity in Lennox-Gastaut syndrome is abnormally enhanced in executive-control and default-mode networks.

    Science.gov (United States)

    Warren, Aaron E L; Abbott, David F; Jackson, Graeme D; Archer, John S

    2017-12-01

    To identify abnormal thalamocortical circuits in the severe epilepsy of Lennox-Gastaut syndrome (LGS) that may explain the shared electroclinical phenotype and provide potential treatment targets. Twenty patients with a diagnosis of LGS (mean age = 28.5 years) and 26 healthy controls (mean age = 27.6 years) were compared using task-free functional magnetic resonance imaging (MRI). The thalamus was parcellated according to functional connectivity with 10 cortical networks derived using group-level independent component analysis. For each cortical network, we assessed between-group differences in thalamic functional connectivity strength using nonparametric permutation-based tests. Anatomical locations were identified by quantifying spatial overlap with a histologically informed thalamic MRI atlas. In both groups, posterior thalamic regions showed functional connectivity with visual, auditory, and sensorimotor networks, whereas anterior, medial, and dorsal thalamic regions were connected with networks of distributed association cortex (including the default-mode, anterior-salience, and executive-control networks). Four cortical networks (left and right executive-control network; ventral and dorsal default-mode network) showed significantly enhanced thalamic functional connectivity strength in patients relative to controls. Abnormal connectivity was maximal in mediodorsal and ventrolateral thalamic nuclei. Specific thalamocortical circuits are affected in LGS. Functional connectivity is abnormally enhanced between the mediodorsal and ventrolateral thalamus and the default-mode and executive-control networks, thalamocortical circuits that normally support diverse cognitive processes. In contrast, thalamic regions connecting with primary and sensory cortical networks appear to be less affected. Our previous neuroimaging studies show that epileptic activity in LGS is expressed via the default-mode and executive-control networks. Results of the present study suggest that

  7. The evaluation of the changes in enzymatic antioxidant reserves and lipid peroxidation in chosen parts of the brain in an animal model of Parkinson disease.

    Science.gov (United States)

    Romuk, Ewa B; Szczurek, Wioletta; Oleś, Michał; Gabrysiak, Artur; Skowron, Marta; Nowak, Przemysław; Birkner, Ewa

    2017-09-01

    Parkinson's disease is a progressive neurodegenerative disorder, characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. The causes of Parkinson's disease are not fully understood; however, increasing evidence implicates oxidative stress. The study was aimed at assessing the nature of the changes in the oxidation-antioxidant balance in the cerebral cortex, striatum, hippocampus, thalamus, and cerebellum in a rat model of Parkinson's disease (PD). Sixteen male Wistar rats were divided into 2 groups: Icontrol, IIParkinson's disease. The 8-weeks-old animals were decapitated, their brains removed and the following structures dissected and then frozen for further biochemical assays: cerebral cortex, striatum, hippocampus, thalamus and cerebellum. The activities of: the catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione S-transferase (GST), superoxide dismutase (SOD) and the isoenzymes: Cu/ZnSOD and MnSOD; together with the malondialdehyde (MDA) and the total oxidative status (TOS) concentrations were measured in each structure. A significantly increased activities of SOD, Cu/ZnSOD, GST and reduced GR activity and an increase of MDA concentration were observed in the striatum of PD rats, comparing to the control group, combined with a significantly reduced activities of GR,SOD, Cu/ZnSOD and an increased GPX activity and MDA concentration in the hippocampus, a significantly lower GR, SOD, MnSOD, Cu/ZnSOD, and GST activities in the cerebral cortex. A significantly lower GR activity, higher CAT activity and MDA concentration in the thalamus and a significantly increased GR activity in the cerebellum were observed in PD rats compared to the corresponding control group. Oxidative stress in PD involves many brain structures and various antioxidant enzymes and oxidative status parameters become dysfunctional, depending on the area of the brain, which might reflect the complexity of the clinical symptoms of PD.

  8. Spinal cord stimulation modulates cerebral function: an fMRI study

    Energy Technology Data Exchange (ETDEWEB)

    Moens, M. [Universitair Ziekenhuis Brussel, Department of Neurosurgery and Center for Neuroscience, Brussels (Belgium); Sunaert, S.; Peeters, R. [UZ Leuven, Katholieke Universiteit Leuven, Department of Radiology, Leuven (Belgium); Marien, P. [ZNA Middelheim General Hospital, Department of Neurology, Antwerp (Belgium); Vrije Universiteit Brussel, Department of Clinical and Experimental Neurolinguistics, Brussels (Belgium); Brouns, R.; Smedt, A. de [Universitair Ziekenhuis Brussel, Department of Neurology and Center for Neuroscience, Brussels (Belgium); Droogmans, S. [Universitair Ziekenhuis Brussel, Department of Cardiology, Brussels (Belgium); Schuerbeek, P. van [Universitair Ziekenhuis Brussel, Department of Radiology, Brussels (Belgium); Poelaert, J. [Universitair Ziekenhuis Brussel, Department of Anesthesiology, Brussels (Belgium); Nuttin, B. [UZ Leuven, Katholieke Universiteit Leuven, Department of Neurosurgery, Leuven (Belgium)

    2012-12-15

    Although spinal cord stimulation (SCS) is widely used for chronic neuropathic pain after failed spinal surgery, little is known about the underlying physiological mechanisms. This study aims to investigate the neural substrate underlying short-term (30 s) SCS by means of functional magnetic resonance imaging in 20 patients with failed back surgery syndrome (FBSS). Twenty patients with FBSS, treated with externalized SCS, participated in a blocked functional magnetic resonance imaging design with stimulation and rest phases of 30 s each, repeated eight times in a row. During scanning, patients rated pain intensity over time using an 11-point numerical rating scale with verbal anchors (0 = no pain at all to 10 = worst pain imaginable) by pushing buttons (left hand, lesser pain; right hand, more pain). This scale was back projected to the patients on a flat screen allowing them to manually direct the pain indicator. To increase the signal-to-noise ratio, the 8-min block measurements were repeated three times. Marked deactivation of the bilateral medial thalamus and its connections to the rostral and caudal cingulate cortex and the insula was found; the study also showed immediate pain relief obtained by short-term SCS correlated negatively with activity in the inferior olivary nucleus, the cerebellum, and the rostral anterior cingulate cortex. Results indicate the key role of the medial thalamus as a mediator and the involvement of a corticocerebellar network implicating the modulation and regulation of averse and negative affect related to pain. The observation of a deactivation of the ipsilateral antero-medial thalamus might be used as a region of interest for further response SCS studies. (orig.)

  9. The spatio-temporal profile of multisensory integration.

    Science.gov (United States)

    Starke, Johanna; Ball, Felix; Heinze, Hans-Jochen; Noesselt, Toemme

    2017-10-23

    Task-irrelevant visual stimuli can enhance auditory perception. However, while there is some neurophysiological evidence for mechanisms that underlie the phenomenon, the neural basis of visually induced effects on auditory perception remains unknown. Combining fMRI and EEG with psychophysical measurements in two independent studies, we identified the neural underpinnings and temporal dynamics of visually induced auditory enhancement. Lower- and higher-intensity sounds were paired with a non-informative visual stimulus, while participants performed an auditory detection task. Behaviourally, visual co-stimulation enhanced auditory sensitivity. Using fMRI, enhanced BOLD signals were observed in primary auditory cortex for low-intensity audiovisual stimuli which scaled with subject-specific enhancement in perceptual sensitivity. Concordantly, a modulation of event-related potentials could already be observed over frontal electrodes at an early latency (30-80 ms), which again scaled with subject-specific behavioural benefits. Later modulations starting around 280 ms, that is in the time range of the P3, did not fit this pattern of brain-behaviour correspondence. Hence, the latency of the corresponding fMRI-EEG brain-behaviour modulation points at an early interplay of visual and auditory signals in low-level auditory cortex, potentially mediated by crosstalk at the level of the thalamus. However, fMRI signals in primary auditory cortex, auditory thalamus and the P50 for higher-intensity auditory stimuli were also elevated by visual co-stimulation (in the absence of any behavioural effect) suggesting a general, intensity-independent integration mechanism. We propose that this automatic interaction occurs at the level of the thalamus and might signify a first step of audiovisual interplay necessary for visually induced perceptual enhancement of auditory perception. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  10. Reading, listening and memory-related brain activity in children with early-stage temporal lobe epilepsy of unknown cause-an fMRI study.

    Science.gov (United States)

    Mankinen, Katariina; Ipatti, Pieta; Harila, Marika; Nikkinen, Juha; Paakki, Jyri-Johan; Rytky, Seppo; Starck, Tuomo; Remes, Jukka; Tokariev, Maksym; Carlson, Synnöve; Tervonen, Osmo; Rantala, Heikki; Kiviniemi, Vesa

    2015-09-01

    The changes in functional brain organization associated with paediatric epilepsy are largely unknown. Since children with epilepsy are at risk of developing learning difficulties even before or shortly after the onset of epilepsy, we assessed the functional organization of memory and language in paediatric patients with temporal lobe epilepsy (TLE) at an early stage in epilepsy. Functional magnetic resonance imaging was used to measure the blood oxygenation level-dependent (BOLD) response to four cognitive tasks measuring reading, story listening, memory encoding and retrieval in a population-based group of children with TLE of unknown cause (n = 21) and of normal intelligence and a healthy age and gender-matched control group (n = 21). Significant BOLD response differences were found only in one of the four tasks. In the story listening task, significant differences were found in the right hemispheric temporal structures, thalamus and basal ganglia. Both activation and deactivation differed significantly between the groups, activation being increased and deactivation decreased in the TLE group. Furthermore, the patients with abnormal electroencephalograms (EEGs) showed significantly increased activation bilaterally in the temporal structures, basal ganglia and thalamus relative to those with normal EEGs. The patients with normal interictal EEGs had a significantly stronger deactivation than those with abnormal EEGs or the controls, the differences being located outside the temporal structures. Our results suggest that TLE entails a widespread disruption of brain networks. This needs to be taken into consideration when evaluating learning abilities in patients with TLE. The thalamus seems to play an active role in TLE. The changes in deactivation may reflect neuronal inhibition. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  11. In vitro evaluation of nicotinic acetylcholine receptors with 2-[{sup 18}F]F-A85380 in Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Schmaljohann, Joern [Department of Neurology, University of Bonn (Germany) and Department of Nuclear Medicine, University of Bonn (Germany)]. E-mail: joern.schmaljohann@ukb.uni-bonn.de; Guendisch, Daniela [Department of Pharmaceutical Chemistry, University of Bonn (Germany); Minnerop, Martina [Department of Neurology, University of Bonn (Germany); Bucerius, Jan [Department of Nuclear Medicine, University of Bonn (Germany); Joe, Alexius [Department of Nuclear Medicine, University of Bonn (Germany); Reinhardt, Michael [Department of Nuclear Medicine, University of Bonn (Germany); Guhlke, Stefan [Department of Nuclear Medicine, University of Bonn (Germany); Biersack, Hans-Juergen [Department of Nuclear Medicine, University of Bonn (Germany); Wuellner, Ullrich [Department of Neurology, University of Bonn (Germany)

    2006-04-15

    Nicotinic acetylcholine receptors (nAChR) are involved in many physiological functions and appear to be affected in neurodegenerative diseases like Alzheimer's disease and Parkinson's disease (PD). Here, we describe the in vitro evaluation of nAChRs in PD with 2-[{sup 18}F]F-A85380, a ligand with high affinity to the {beta}2 nAChR subunit. Autoradiography with 2-[{sup 18}F]F-A85380 in untreated rat brain corresponded to the known distribution of {alpha}4{beta}2 nAChRs with high uptake in the thalamus, moderate uptake in the striatum and cortex and low uptake in the cerebellum (47%, 43% and 19% of the thalamus, respectively). The localization of {alpha}4{beta}2 nAChRs in the striatum was investigated in rodents with unilateral lesion of the substantia nigra. 2-[{sup 18}F]F-A85380 binding was significantly reduced in the striatum ipsilateral to the lesion side (to 64% of the contralateral side), indicating that a fraction of {alpha}4{beta}2 nAChRs is located on dopaminergic terminals, whereas another fraction resides on striatal interneurons or cortical afferents. Similarly, in human brain sections of PD patients, 2-[{sup 18}F]F-A85380 uptake was significantly reduced not only in the caudate and putamen but also in the thalamus (approximately 30% of the binding of control brain in all three regions); within the striatum, nAChRs in the putamen were significantly more severely affected as in the caudate. The observed pattern of {alpha}4{beta}2* nAChR loss demonstrates the potential of 2-[{sup 18}F]F-A85380 for further investigations of this positron emission tomography ligand for in vivo studies of {alpha}4{beta}2* nAChRs in PD.

  12. Decreased norepinephrine transporter availability in obesity: Positron Emission Tomography imaging with (S,S)-[(11)C]O-methylreboxetine.

    Science.gov (United States)

    Li, Chiang-shan R; Potenza, Marc N; Lee, Dianne E; Planeta, Beata; Gallezot, Jean-Dominique; Labaree, David; Henry, Shannan; Nabulsi, Nabeel; Sinha, Rajita; Ding, Yu-Shin; Carson, Richard E; Neumeister, Alexander

    2014-02-01

    Noradrenergic dysfunction is implicated in obesity. The norepinephrine transporter (NET) regulates the synaptic availability of norepinephrine. However, NET availability has not been previously characterized in vivo in obese people using Positron Emission Tomography (PET) imaging. Here we report findings evaluating NET availability in individuals with obesity and matched lean (i.e., normal weight) comparison subjects. Seventeen obese but otherwise healthy individuals with a mean±SD body mass index (BMI) of 34.7±2.6 and 17 lean individuals with a mean±SD BMI of 23.1±1.4 were studied using a high-resolution research tomograph (HRRT) and (S,S)-[(11)C]O-methylreboxetine ([(11)C]-MRB), a radioligand selective for the NET. The regional brain NET binding potential (BPND) was estimated by the multilinear reference tissue model 2 (MRTM2) with the occipital cortex as a reference region. BPND for regions of interest were obtained with the Automated Anatomic Labeling (AAL) template registered to individual's structural MR scans. Obese individuals had lower NET BPND values in the thalamus (p<0.038, 27% reduction) including within the pulvinar (p<0.083, 30% reduction), but not in the hypothalamus, locus coeruleus or the raphe nuclei, compared to lean individuals. When age was included as a covariate, the difference in NET BPND values remained significant in the thalamus (p<0.025) and pulvinar (p<0.042). These results indicate that NET availability is decreased in the thalamus, including the pulvinar, in obese individuals. These findings further support data indicating noradrenergic dysfunction in obesity and suggest impaired NE clearance in obesity. © 2013 Elsevier Inc. All rights reserved.

  13. Decreased Norepinephrine Transporter Availability in Obesity: Positron Emission Tomography Imaging with (S,S)-[11C]O-Methylreboxetine

    Science.gov (United States)

    Li, Chiang-shan R.; Potenza, Marc N.; Lee, Dianne E.; Planeta, Beata; Gallezot, Jean-Dominique; Labaree, David; Henry, Shannan; Nabulsi, Nabeel; Sinha, Rajita; Ding, Yu-Shin; Carson, Richard E.; Neumeister, Alexander

    2013-01-01

    Objectives Noradrenergic dysfunction is implicated in obesity. The norepinephrine transporter (NET) regulates the synaptic availability of norepinephrine. However, NET availability has not been previously characterized in vivo in obese people using Positron Emission Tomography (PET) imaging. Here we report findings evaluating NET availability in individuals with obesity and matched lean (i.e., normal weight) comparison subjects. Methods Seventeen obese but otherwise healthy individuals with a mean±SD body mass index (BMI) of 34.7±2.6 and 17 lean individuals with a mean±SD BMI of 23.1±1.4 were studied using a High-Resolution Research Tomograph (HRRT) and (S,S)-[11C]O-methylreboxetine ([11C]-MRB), a radioligand selective for the NET. The regional brain NET binding potential (BPND) was estimated by the multilinear reference tissue model 2 (MRTM2) with the occipital cortex as a reference region. BPND for regions of interest were obtained with the Automated Anatomic Labeling (AAL) template registered to individual’s structural MR scans. Results Obese individuals had lower NET BPND values in the thalamus (p<0.038, 27% reduction) including within the pulvinar (p<0.083, 30% reduction), but not in the hypothalamus, locus coeruleus or the raphe nuclei, compared to lean individuals. When age was included as a covariate, the difference in NET BPND values remained significant in the thalamus (p<0.025) and pulvinar (p<0.042). Conclusions These results indicate that NET availability is decreased in the thalamus, including the pulvinar, in obese individuals. These findings further support data indicating noradrenergic dysfunction in obesity and suggest impaired NE clearance in obesity. PMID:24121204

  14. Quantitative Visualization of Dynamic Tracer Transportation in the Extracellular Space of Deep Brain Regions Using Tracer-Based Magnetic Resonance Imaging.

    Science.gov (United States)

    Hou, Jin; Wang, Wei; Quan, Xianyue; Liang, Wen; Li, Zhiming; Chen, Deji; Han, Hongbin

    2017-09-03

    BACKGROUND This study assessed an innovative tracer-based magnetic resonance imaging (MRI) system to visualize the dynamic transportation of tracers in regions of deep brain extracellular space (ECS) and to measure transportation ability and ECS structure. MATERIAL AND METHODS Gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) was the chosen tracer and was injected into the caudate nucleus and thalamus. Real-time dynamic transportation of Gd-DTPA in ECS was observed and the results were verified by laser scanning confocal microscopy. Using Transwell assay across the blood-brain barrier, a modified diffusion equation was further simplified. Effective diffusion coefficient D* and tortuosity λ were calculated. Immunohistochemical staining and Western blot analysis were used to investigate the extracellular matrix contributing to ECS structure. RESULTS Tracers injected into the caudate nucleus were transported to the ipsilateral frontal and temporal cortices away from the injection points, while both of them injected into the thalamus were only distributed on site. Although the caudate nucleus was closely adjacent to the thalamus, tracer transportation between partitions was not observed. In addition, D* and the λ showed statistically significant differences between partitions. ECS was shown to be a physiologically partitioned system, and its division is characterized by the unique distribution territory and transportation ability of substances located in it. Versican and Tenascin R are possible contributors to the tortuosity of ECS. CONCLUSIONS Tracer-based MRI will improve our understanding of the brain microenvironment, improve the techniques for local delivery of drugs, and highlight brain tissue engineering fields in the future.

  15. Fish oil supplementation associated with decreased cellular degeneration and increased cellular proliferation 6 weeks after middle cerebral artery occlusion in the rat

    Directory of Open Access Journals (Sweden)

    Pascoe MC

    2015-01-01

    Full Text Available Michaela C Pascoe,1 David W Howells, 2David P Crewther,1 Leeanne M Carey,2,3 Sheila G Crewther4 1Brain Sciences Institute, Swinburne University, ²Florey Institute of Neuroscience and Mental Health, University of Melbourne, 3Department of Occupational Therapy, School of Allied Health La Trobe University, 4School of Psychological Science, La Trobe University, Melbourne, VIC, Australia Abstract: Anti-inflammatory long-chain omega-3 polyunsaturated fatty acids (n-3-LC-PUFAs are both neuroprotective and have antidepressive effects. However the influence of dietary supplemented n-3-LC-PUFAs on inflammation-related cell death and proliferation after middle cerebral artery occlusion (MCAo-induced stroke is unknown. We have previously demonstrated that anxiety-like and hyperactive locomotor behaviors are reduced in n-3-LC-PUFA-fed MCAo animals. Thus in the present study, male hooded Wistar rats were exposed to MCAo or sham surgeries and examined behaviorally 6 weeks later, prior to euthanasia and examination of lesion size, cell death and proliferation in the dentate gyrus, cornu ammonis region of the hippocampus of the ipsilesional hemispheres, and the thalamus of the ipsilesional and contralesional hemispheres. Markers of cell genesis and cell degeneration in the hippocampus or thalamus of the ipsilesional hemisphere did not differ between surgery and diet groups 6 weeks post MCAo. Dietary supplementation with n-3-LC-PUFA decreased cell degeneration and increased cell proliferation in the thalamic region of the contralesional hemisphere. MCAo–associated cell degeneration in the hippocampus and thalamus positively correlated with anxiety-like and hyperactive locomotor behaviors previously reported in these animals. These results suggest that anti-inflammatory n-3-LC-PUFA supplementation appears to have cellular protective effects after MCAo in the rat, which may affect behavioral outcomes. Keywords: apoptosis, polyunsaturated fatty acids

  16. Reduced Metabolsim in Brain 'Control Networks' Following Cocaine-Cues Exposure in Female Cocaine Abusers

    Energy Technology Data Exchange (ETDEWEB)

    Volkow, N.D.; Wang, G.; Volkow, N.D.; Tomasi, D.; Wang, G.-J.; Fowler, J.S.; Telang, F.; Goldstein, R.Z.; Alia-Klein, N.; Wong, C.T.

    2011-03-01

    Gender differences in vulnerability for cocaine addiction have been reported. Though the mechanisms are not understood, here we hypothesize that gender differences in reactivity to conditioned-cues, which contributes to relapse, are involved. To test this we compared brain metabolism (using PET and {sup 18}FDG) between female (n = 10) and male (n = 16) active cocaine abusers when they watched a neutral video (nature scenes) versus a cocaine-cues video. Self-reports of craving increased with the cocaine-cue video but responses did not differ between genders. In contrast, changes in whole brain metabolism with cocaine-cues differed by gender (p<0.05); females significantly decreased metabolism (-8.6% {+-} 10) whereas males tended to increase it (+5.5% {+-} 18). SPM analysis (Cocaine-cues vs Neutral) in females revealed decreases in frontal, cingulate and parietal cortices, thalamus and midbrain (p<0.001) whereas males showed increases in right inferior frontal gyrus (BA 44/45) (only at p<0.005). The gender-cue interaction showed greater decrements with Cocaine-cues in females than males (p<0.001) in frontal (BA 8, 9, 10), anterior cingulate (BA 24, 32), posterior cingulate (BA 23, 31), inferior parietal (BA 40) and thalamus (dorsomedial nucleus). Females showed greater brain reactivity to cocaine-cues than males but no differences in craving, suggesting that there may be gender differences in response to cues that are not linked with craving but could affect subsequent drug use. Specifically deactivation of brain regions from 'control networks' (prefrontal, cingulate, inferior parietal, thalamus) in females could increase their vulnerability to relapse since it would interfere with executive function (cognitive inhibition). This highlights the importance of gender tailored interventions for cocaine addiction.

  17. Altered Functional Connectivity in Patients with Subcortical Vascular Cognitive Impairment--A Resting-State Functional Magnetic Resonance Imaging Study.

    Directory of Open Access Journals (Sweden)

    Weina Ding

    Full Text Available Recent neuroimaging studies have shown that people with subcortical vascular cognitive impairment (sVCI have structural and functional abnormalities in the frontal lobe and subcortical brain sites. In this study, we used seed-based resting-state functional connectivity (rsFC analysis and voxel-mirrored homotopic connectivity (VMHC techniques to investigate the alteration of rsFC in patients with sVCI. rsFC and structural magnetic resonance images were acquired for 51 patients with subcortical cerebrovascular disease. All patients were subdivided based on cognitive status into 29 with sVCI and 22 controls; patient characteristics were matched. rsFC of the posterior cingulate cortex (PCC and VMHC were calculated separately, and rsFC of the PCC and VMHC between the two groups were compared. The regions showing abnormal rsFC of the PCC or VMHC in sVCI patients were adopted as regions of interest for correlation analyses. Our results are as follows: The patients with sVCI exhibited increases in rsFC in the left middle temporal lobe, right inferior temporal lobe and left superior frontal gyrus, and significant decreases in rsFC of the left thalamus with the PCC. sVCI patients showed a significant deficit in VMHC between the bilateral lingual gyrus, putamen, and precentral gyrus. Additionally, the z-memory score was significantly positively associated with connectivity between the left thalamus and the PCC (r = 0.41, p = 0.03, uncorrected in the sVCI group. Our findings suggest that the frontal lobe and subcortical brain sites play an important role in the pathogenesis of sVCI. Furthermore, rsFC between the left thalamus and the PCC might indicate the severity of sVCI.

  18. Signal intensity at unenhanced T1-weighted magnetic resonance in the globus pallidus and dentate nucleus after serial administrations of a macrocyclic gadolinium-based contrast agent in children

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    Rossi Espagnet, Maria Camilla; Bernardi, Bruno; Figa-Talamanca, Lorenzo [Ospedale Pediatrico Bambino Gesu, IRCCS, Neuroradiology Unit, Imaging Department, Rome (Italy); Pasquini, Luca [Ospedale Pediatrico Bambino Gesu, IRCCS, Neuroradiology Unit, Imaging Department, Rome (Italy); University Sapienza, Neuroradiology Unit, Azienda Ospedaliera Sant' Andrea, Rome (Italy); Toma, Paolo [Ospedale Pediatrico Bambino Gesu, IRCCS, Department of Imaging, Rome (Italy); Napolitano, Antonio [Ospedale Pediatrico Bambino Gesu, IRCCS, Enterprise Risk Management, Medical Physics Department, Rome (Italy)

    2017-09-15

    Few studies have been conducted on the relations between T1-weighted signal intensity changes in the pediatric brain following gadolinium-based contrast agent (GBCA) exposure. The purpose of this study is to investigate the effect of multiple administrations of a macrocyclic GBCA on signal intensity in the globus pallidus and dentate nucleus of the pediatric brain on unenhanced T1-weighted MR images. This retrospective study included 50 patients, mean age: 8 years (standard deviation: 4.8 years), with normal renal function exposed to ≥6 administrations of the same macrocyclic GBCA (gadoterate meglumine) and a control group of 59 age-matched GBCA-naive patients. The globus pallidus-to-thalamus signal intensity ratio and dentate nucleus-to-pons signal intensity ratio were calculated from unenhanced T1-weighted images for both patients and controls. A mixed linear model was used to evaluate the effects on signal intensity ratios of the number of GBCA administrations, the time interval between administrations, age, radiotherapy and chemotherapy. T-test analyses were performed to compare signal intensity ratio differences between successive administrations and baseline MR signal intensity ratios in patients compared to controls. P-values were considered significant if <0.05. A significant effect of the number of GBCA administrations on relative signal intensities globus pallidus-to-thalamus (F[8]=3.09; P=0.002) and dentate nucleus-to-pons (F[8]=2.36; P=0.021) was found. The relative signal intensities were higher at last MR examination than at baseline (P<0.001). Quantitative analysis evaluation of globus pallidus:thalamus and dentate nucleus:pons of the pediatric brain demonstrated an increase after serial administrations of macrocyclic GBCA. Further research is necessary to fully understand GBCA pharmacokinetic in children. (orig.)

  19. Cortically-controlled population stochastic facilitation as a plausible substrate for guiding sensory transfer across the thalamic gateway.

    Directory of Open Access Journals (Sweden)

    Sébastien Béhuret

    Full Text Available The thalamus is the primary gateway that relays sensory information to the cerebral cortex. While a single recipient cortical cell receives the convergence of many principal relay cells of the thalamus, each thalamic cell in turn integrates a dense and distributed synaptic feedback from the cortex. During sensory processing, the influence of this functional loop remains largely ignored. Using dynamic-clamp techniques in thalamic slices in vitro, we combined theoretical and experimental approaches to implement a realistic hybrid retino-thalamo-cortical pathway mixing biological cells and simulated circuits. The synaptic bombardment of cortical origin was mimicked through the injection of a stochastic mixture of excitatory and inhibitory conductances, resulting in a gradable correlation level of afferent activity shared by thalamic cells. The study of the impact of the simulated cortical input on the global retinocortical signal transfer efficiency revealed a novel control mechanism resulting from the collective resonance of all thalamic relay neurons. We show here that the transfer efficiency of sensory input transmission depends on three key features: i the number of thalamocortical cells involved in the many-to-one convergence from thalamus to cortex, ii the statistics of the corticothalamic synaptic bombardment and iii the level of correlation imposed between converging thalamic relay cells. In particular, our results demonstrate counterintuitively that the retinocortical signal transfer efficiency increases when the level of correlation across thalamic cells decreases. This suggests that the transfer efficiency of relay cells could be selectively amplified when they become simultaneously desynchronized by the cortical feedback. When applied to the intact brain, this network regulation mechanism could direct an attentional focus to specific thalamic subassemblies and select the appropriate input lines to the cortex according to the descending

  20. Lateralization of Neurobiological Response in Adolescents with Post-Traumatic Stress Disorder Related to Severe Childhood Sexual Abuse: the Tri-Modal Reaction (T-MR) Model of Protection.

    Science.gov (United States)

    Mutluer, Tuba; Şar, Vedat; Kose-Demiray, Çiğdem; Arslan, Harun; Tamer, Sibel; Inal, Serap; Kaçar, Anıl Ş

    2018-01-01

    This study inquires into neurobiological response to stress and its clinical correlates among adolescents with post-traumatic stress disorder (PTSD). Structural magnetic resonance imaging (MRI) measures of cerebral anatomy were carried out on 23 female adolescents with PTSD related to severe childhood sexual abuse and 21 matched healthy controls. Clinician Administered PTSD Scale for Children and Adolescents, Adolescent Dissociative Experiences Scale, Childhood Trauma Questionnaire, Schedule for Affective Disorders and Schizophrenia for School Age Children, Beck Depression Scale, and a set of neuro-cognitive tests were administered to all participants. Compared to controls, PTSD group bilaterally had smaller amygdala, hippocampus, anterior cingulate, and thinner prefrontal cortex but normal thalamus. Further analyses within the PTSD group suggested an association between symptoms of PTSD and sizes of right brain structures including smaller amygdala but larger hippocampus and anterior cingulate. Thinner right prefrontal cortex and larger right thalamus seemed to be related to denial and response prevention, respectively. Being related to both hemispheres, dissociative amnesia was negatively associated with proportion of the right amygdala to right thalamus and to both left and right prefrontal cortex. Suggesting a neuro-protective effect against traumatic stress at least through adolescence, depersonalization-derealization and identity alteration were correlated with thicker left prefrontal cortex. Unlike the lateralization within PTSD group, correlations between regions of interest were rather symmetrical in controls. The graded response to stress seemed to be aimed at mental protection by lateralization of brain functions and possibly diminished connection between two hemispheres. A Tri-Modal Reaction (T-MR) Model of protection is proposed.

  1. A study of glutamate levels, NR1, NR2A, NR2B receptors and oxidative stress in rat model of Japanese encephalitis.

    Science.gov (United States)

    Chauhan, Prashant Singh; Misra, Usha Kant; Kalita, Jayantee

    2017-03-15

    There is paucity of studies on the role of glutamate excitotoxicity in cell damage in Japanese encephalitis. In this study the glutamate levels and its NMDA receptors, and oxidative stress markers in different brain regions have been evaluated and correlated with neurobehavioral changes at different time points. Twelve day old Wistar rats were inoculated with 3×10(6)pfu/ml intracerebrally. The neurobehavioral effects were evaluated by spontaneous locomotor activity (SLA), grip strength and rota rod test on 10, 33 and 48days post inoculation (dpi). Glutamate level was evaluated by enzyme linked immunosorbent assay, mRNA gene expression of ionotropic glutamate receptors N-methyl d-aspartate (NMDA) receptor 1, 2A and 2B (NR1, NR2A and NR2B) were evaluated by real time PCR. Malondialdehyde (MDA), glutathione (GSH) and glutathione peroxidase (GPx) levels were measured by spectrophotometer in different brain regions of JEV infected rats on 10, 33 and 48dpi. There was significant increase in motor deficit, grip strength and decreased locomotor activity on 10 and 33dpi. Glutamate levels were increased in thalamus, midbrain, frontal cortex, striatum and cerebellum on 10 and 33dpi and were followed by a recovery on 48dpi. Glutamate NMDR receptors NR1, NR2A and NR2B were reduced in thalamus, midbrain, frontal cortex, striatum and cerebellum on 10dpi which was followed by recovery after 33dpi. A significant increase in MDA level in thalamus, midbrain, frontal cortex, striatum and cerebellum was noted on 10 and 33dpi. The antioxidant GSH and GPx were significantly reduced in these brain regions on 10 and 33dpi. Glutamate, MDA, GSH and GPx correlated in different brain regions as the disease progress. Increased Glutamate level may be related to oxidative stress and may be responsible for behavioral alterations in rat model of Japanese encephalitis. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Early magnetic resonance detection of cortical necrosis and acute network injury associated with neonatal and infantile cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Okabe, Tetsuhiko; Aida, Noriko; Nozawa, Kumiko [Kanagawa Children' s Medical Center, Department of Radiology, Yokohama (Japan); Niwa, Tetsu [Kanagawa Children' s Medical Center, Department of Radiology, Yokohama (Japan); Tokai University School of Medicine, Department of Radiology, Isehara (Japan); Shibasaki, Jun [Kanagawa Children' s Medical Center, Department of Neonatology, Yokohama (Japan); Osaka, Hitoshi [Kanagawa Children' s Medical Center, Department of Neurology, Yokohama (Japan)

    2014-05-15

    Knowledge of MRI findings in pediatric cerebral infarction is limited. To determine whether cortical necrosis and network injury appear in the acute phase in post-stroke children and to identify anatomical location of acute network injury and the ages at which these phenomena are seen. Images from 12 children (age range: 0-9 years; neonates [<1 month], n=5; infants [1 month-12 months], n=3; others [≥1 year], n=4) with acute middle cerebral artery (MCA) cortical infarction were retrospectively analyzed. Cortical necrosis was defined as hyperintense cortical lesions on T1-weighted imaging that lacked evidence of hemorrhage. Acute network injury was defined as hyperintense lesions on diffusion-weighted imaging that were not in the MCA territory and had fiber connections with the affected cerebral cortex. MRI was performed within the first week after disease onset. Cortical necrosis was only found in three neonates. Acute network injury was seen in the corticospinal tract (CST), thalamus and corpus callosum. Acute network injury along the CST was found in five neonates and one 7-month-old infant. Acute network injury was evident in the thalamus of four neonates and two infants (ages 4 and 7 months) and in the corpus callosum of five neonates and two infants (ages 4 and 7 months). The entire thalamus was involved in three children when infarction of MCA was complete. In acute MCA cortical infarction, MRI findings indicating cortical necrosis or acute network injury was frequently found in neonates and early infants. Response to injury in a developing brain may be faster than that in a mature one. (orig.)

  3. Characteristics of seizure-induced signal changes on MRI in patients with first seizures.

    Science.gov (United States)

    Kim, Si Eun; Lee, Byung In; Shin, Kyong Jin; Ha, Sam Yeol; Park, JinSe; Park, Kang Min; Kim, Hyung Chan; Lee, Joonwon; Bae, Soo-Young; Lee, Dongah; Kim, Sung Eun

    2017-05-01

    The aim of this study was to investigate the predictive factors and identify the characteristics of the seizure-induced signal changes on MRI (SCM) in patients with first seizures. We conducted a retrospective study of patients with first seizures from March 2010 to August 2014. The inclusion criteria for this study were patients with 1) first seizures, and 2) MRI and EEG performed within 24h of the first seizures. The definition of SCM was hyper-intensities in the brain not applying to cerebral arterial territories. Multivariate logistic regression was performed with or without SCM as a dependent variable. Of 431 patients with seizures visiting the ER, 69 patients met the inclusion criteria. Of 69 patients, 11 patients (15.9%) had SCM. Epileptiform discharge on EEG (OR 29.7, 95% CI 1.79-493.37, p=0.018) was an independently significant variable predicting the presence of SCM in patients with first seizures. In addition, the topography of SCM was as follows; i) ipsilateral hippocampus, thalamus and cerebral cortex (5/11), ii) unilateral cortex (4/11), iii) ipsilateral thalamus and cerebral cortex (1/11), iv) bilateral hippocampus (1/11). Moreover, 6 out of 7 patients who underwent both perfusion CT and MRI exhibited unilateral cortical hyperperfusion with ipsilateral thalamic involvement reflecting unrestricted vascular territories. There is an association between epileptiform discharges and SCM. Additionally, the involvement of the unilateral cortex and ipsilateral thalamus in SCM and its hyperperfusion state could be helpful in differentiating the consequences of epileptic seizures from other pathologies. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  4. Maturing thalamocortical functional connectivity across development

    Directory of Open Access Journals (Sweden)

    Damien Fair

    2010-05-01

    Full Text Available Recent years have witnessed a surge of investigations examining functional brain organization using resting-state functional connectivity MRI (rs-fcMRI. To date, this method has been used to examine systems organization in typical and atypical developing populations. While the majority of these investigations have focused on cortical-cortical interactions, cortical-subcortical interactions also mature into adulthood. Innovative work by Zhang et al (Zhang et al., 2008 in adults have identified methods that utilize rs-fcMRI and known thalamo-cortical topographic segregation to identify functional boundaries in the thalamus that are remarkably similar to known thalamic nuclear grouping. However, despite thalamic nuclei being well formed early in development, the developmental trajectory of functional thalamo-cortical relations remains unexplored. Thalamic maps generated by rs-fcMRI are based on functional relationships, and should modify with the dynamic thalamo-cortical changes that occur throughout maturation. To examine this possibility, we employed a strategy as previously described by Zhang et al to a sample of healthy children, adolescents, and adults. We found strengthening functional connectivity of the frontal cortex with dorsal/anterior subdivisions of the thalamus across age groups. Temporal lobe connectivity with ventral/midline/posterior subdivisions of the thalamus weakened with age. Changes in sensory and motor thalamo-cortical interactions were limited. These findings are consistent with known anatomical and physiological cortical-subcortical changes over development. The methods and developmental context provided here will be important for relating how cortical-subcortical interactions relate to models of typically developing behavior and developmental neuropsychiatric disorders.

  5. Late-stage α-synuclein accumulation in TNWT-61 mouse model of Parkinson's disease detected by diffusion kurtosis imaging.

    Science.gov (United States)

    Khairnar, Amit; Ruda-Kucerova, Jana; Drazanova, Eva; Szabó, Nikoletta; Latta, Peter; Arab, Anas; Hutter-Paier, Birgit; Havas, Daniel; Windisch, Manfred; Sulcova, Alexandra; Starcuk, Zenon; Király, András; Rektorova, Irena

    2015-12-19

    Diffusion kurtosis imaging (DKI) by measuring non-Gaussian diffusion allows an accurate estimation of the distribution of water molecule displacement and may correctly characterize microstructural brain changes caused by neurodegeneration. The aim of the present study was to evaluate the ability of DKI to detect changes induced by α-synuclein (α-Syn) accumulation in α-Syn overexpressing transgenic mice (TNWT-61) in both gray matter (GM) and white matter (WM) using region of interest (ROI) and tract-based spatial statistics (TBSS) analyses respectively and to explore the relationship between α-Syn accumulation and DKI metrics in our regions of interest. Fourteen-month-old TNWT-61 mice and wild-type (WT) littermates underwent in vivo DKI scanning using the Bruker Avance 9.4 Tesla MRI system. ROI analysis in the GM regions substantia nigra, striatum, hippocampus, sensorimotor cortex, and thalamus and TBSS analysis in WM were performed. Immunohistochemistry for α-Syn was performed in TNWT-61 mice and correlated with DKI findings. We found increased kurtosis and decreased diffusivity values in GM regions such as the thalamus and sensorimotor cortex, and in WM regions such as the external and internal capsule, mamillothalamic tract, anterior commissure, cingulum, and corpus callosum in TNWT-61 mice as compared to WT mice. Furthermore, we report for the first time that α-Syn accumulation is positively correlated with kurtosis and negatively correlated with diffusivity in the thalamus. The study provides evidence of an association between the amount of α-Syn and the magnitude of DKI metric changes in the ROIs, with the potential of improving the clinical diagnosis of PD. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  6. Seizure susceptibility and the brain regional sensitivity to oxidative stress in male and female rats in the lithium-pilocarpine model of temporal lobe epilepsy.

    Science.gov (United States)

    Peternel, Sandra; Pilipović, Kristina; Zupan, Gordana

    2009-04-30

    Several studies have shown the existence of sex differences in the sensitivity to various convulsants in animals and to the development of some epilepsy types in humans. The purpose of this study was to investigate whether there are sex differences in seizure susceptibility and sensitivity of different brain regions to oxidative stress in rats with status epilepticus (SE) induced by lithium-pilocarpine administration, that provides a common experimental model of temporal lobe epilepsy (TLE) in humans. Latencies to isolated full limbic seizures or SE onset as well as the number of the animals presenting full limbic seizures, SE or full limbic seizures that progressed to SE were recorded for 2 h after pilocarpine administration. Number of animals which survived 24 h after SE onset was also monitored. Levels of lipid peroxidation as well as the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in the piriform and entorhinal cortices, temporal neocortex, thalamus, and hippocampus in rats of both sexes, at 24 h after SE onset were determined. Results of our study showed that males developed full limbic seizures and SE more rapidly and in greater number than females. Levels of lipid peroxidation in all brain regions examined, the SOD activities in the piriform and entorhinal cortices, and temporal neocortex as well as the GSH-Px activities in the piriform and entorhinal cortices, and thalamus were significantly higher in rats with SE in comparison to the values of mentioned biochemical parameters in rats of the control groups. Lipid peroxidation level in the temporal neocortex as well as the GSH-Px activity in the hippocampus in male rats were significantly higher in comparison to the values registered in females. With the exception of the thalamus, where SOD activity in male rats with SE was significantly higher in relation to the respective control group and also to females with SE, sex differences in the response of other brain regions

  7. Neural correlates of stress and favorite-food cue exposure in adolescents: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Hommer, Rebecca E; Seo, Dongju; Lacadie, Cheryl M; Chaplin, Tara M; Mayes, Linda C; Sinha, Rajita; Potenza, Marc N

    2013-10-01

    Adolescence is a critical period of neurodevelopment for stress and appetitive processing, as well as a time of increased vulnerability to stress and engagement in risky behaviors. This study was conducted to examine brain activation patterns during stress and favorite-food-cue experiences relative to a neutral-relaxing condition in adolescents. Functional magnetic resonance imaging was employed using individualized script-driven guided imagery to compare brain responses with such experiences in 43 adolescents. Main effects of condition and gender were found, without a significant gender-by-condition interaction. Stress imagery, relative to neutral, was associated with activation in the caudate, thalamus, left hippocampus/parahippocampal gyrus, midbrain, left superior/middle temporal gyrus, and right posterior cerebellum. Appetitive imagery of favorite food was associated with caudate, thalamus, and midbrain activation compared with the neutral-relaxing condition. To understand neural correlates of anxiety and craving, subjective (self-reported) measures of stress-induced anxiety and favorite-food-cue-induced craving were correlated with brain activity during stress and appetitive food-cue conditions, respectively. High self-reported stress-induced anxiety was associated with hypoactivity in the striatum, thalamus, hippocampus, and midbrain. Self-reported favorite-food-cue-induced craving was associated with blunted activity in cortical-striatal regions, including the right dorsal and ventral striatum, medial prefrontal cortex, motor cortex, and left anterior cingulate cortex. These findings in adolescents indicate the activation of predominantly subcortical-striatal regions in the processing of stressful and appetitive experiences and link hypoactive striatal circuits to self-reported stress-induced anxiety and cue-induced favorite-food craving. Copyright © 2012 Wiley Periodicals, Inc.

  8. Impairment in material-specific long-term memory following unilateral mediodorsal thalamic damage and presumed partial disconnection of the mammillo-thalamic tract.

    Science.gov (United States)

    Edelstyn, Nicola M J; Mayes, Andrew R; Denby, Christine; Ellis, Simon J

    2012-03-01

    Neuropsychological findings suggest material-specific lateralization of the medial temporal lobe's role in long-term memory, with greater left-sided involvement in verbal memory, and greater right-sided involvement in visual memory. Whether material-specific lateralization of long-term memory also extends to the anteromedial thalamus remains uncertain. We report two patients with unilateral right (OG) and left (SM) mediodorsal thalamic pathology plus probable correspondingly lateralized damage of the mammillo-thalamic tract. The lesions were mapped using high-resolution structural magnetic resonance imaging and schematically reconstructed. Mean absolute volume estimates for the mammillary bodies, hippocampus, perirhinal cortex, and ventricles are also presented. Estimates of visual and verbal recall and item recognition memory were obtained using the Doors and People, the Rey Complex Figure Test, and the Logical Memory subtests of the Wechsler Memory Scales. Each patient's performance was compared to a group of healthy volunteers matched for demographic characteristics, premorbid IQ, and current levels of functioning. A striking double dissociation was evident in material-specific long-term memory, with OG showing significant impairments in visual memory but not verbal memory, and SM showing the opposite profile of preserved visual memory and significantly impaired verbal memory. These impairments affected both recall and item recognition. The reported double dissociation provides the strongest evidence yet that material-specific lateralization of long-term memory also extends to the anteromedial thalamus. The findings are also discussed in relation to proposals that distinct anatomical regions within the medial temporal lobe, anteromedial thalamus, and associated tracts make qualitatively different contributions to recall and item recognition. ©2011 The British Psychological Society.

  9. The nondecussating pathway of the dentatorubrothalamic tract in humans: human connectome-based tractographic study and microdissection validation.

    Science.gov (United States)

    Meola, Antonio; Comert, Ayhan; Yeh, Fang-Cheng; Sivakanthan, Sananthan; Fernandez-Miranda, Juan C

    2016-05-01

    OBJECT The dentatorubrothalamic tract (DRTT) is the major efferent cerebellar pathway arising from the dentate nucleus (DN) and decussating to the contralateral red nucleus (RN) and thalamus. Surprisingly, hemispheric cerebellar output influences bilateral limb movements. In animals, uncrossed projections from the DN to the ipsilateral RN and thalamus may explain this phenomenon. The aim of this study was to clarify the anatomy of the dentatorubrothalamic connections in humans. METHODS The authors applied advanced deterministic fiber tractography to a template of 488 subjects from the Human Connectome Project (Q1-Q3 release, WU-Minn HCP consortium) and validated the results with microsurgical dissection of cadaveric brains prepared according to Klingler's method. RESULTS The authors identified the "classic" decussating DRTT and a corresponding nondecussating path (the nondecussating DRTT, nd-DRTT). Within each of these 2 tracts some fibers stop at the level of the RN, forming the dentatorubro tract and the nondecussating dentatorubro tract. The left nd-DRTT encompasses 21.7% of the tracts and 24.9% of the volume of the left superior cerebellar peduncle, and the right nd-DRTT encompasses 20.2% of the tracts and 28.4% of the volume of the right superior cerebellar peduncle. CONCLUSIONS The connections of the DN with the RN and thalamus are bilateral, not ipsilateral only. This affords a potential anatomical substrate for bilateral limb motor effects originating in a single cerebellar hemisphere under physiological conditions, and for bilateral limb motor impairment in hemispheric cerebellar lesions such as ischemic stroke and hemorrhage, and after resection of hemispheric tumors and arteriovenous malformations. Furthermore, when a lesion is located on the course of the dentatorubrothalamic system, a careful preoperative tractographic analysis of the relationship of the DRTT, nd-DRTT, and the lesion should be performed in order to tailor the surgical approach properly

  10. Sleep in children with cancer: case review of 70 children evaluated in a comprehensive pediatric sleep center.

    Science.gov (United States)

    Rosen, Gerald; Brand, Sarah R

    2011-07-01

    The goal of this study was to characterize the sleep problems of children with cancer who were referred for a comprehensive sleep evaluation. A retrospective case series review was conducted of all children with cancer referred to the pediatric sleep clinic from 1994 to 2009 for evaluation of a sleep problem. Seventy children were seen and evaluated during this interval; all had a complete sleep history taken, and further objective sleep evaluations were performed as part of their evaluation only when clinically indicated. An overnight polysomnogram was performed in 53 children. In 36 children with a history of excessive daytime sleepiness (EDS), a multiple sleep latency study was performed the following day. Seven children had a 3-4-week actigraphic study. Children with neoplasms of central nervous system (CNS) involving the hypothalamus, thalamus, and brainstem were the most commonly referred children and had the most frequent and severe sleep problems. Excessive daytime sleepiness was the most common sleep problem, seen in 60% of children with cancer and in 80% of children with CNS neoplasms involving the hypothalamus, thalamus, and brainstem. Sleep disordered breathing (SDB) was present in 40% of the entire group of children with cancer and 46% of children with neoplasms involving the hypothalamus, thalamus, and brainstem. Children with CNS neoplasms often had more than one sleep problem, most commonly EDS and SDB. In these children, correction of the SDB often did not eliminate the EDS. In children with leukemia, insomnia was the most common sleep problem identified, present in 39%. The causes of the sleep problems were varied and included neurologic injury caused by the neoplasm and/or the CNS-directed treatments; seizures, adenotonsillar hypertrophy, medication side effects, obesity, pain, anxiety, and drug abuse. Some of the sleep problems were present before the diagnosis of cancer, though most developed after treatment was begun. A wide range of

  11. Human auditory evoked potentials. I - Evaluation of components

    Science.gov (United States)

    Picton, T. W.; Hillyard, S. A.; Krausz, H. I.; Galambos, R.

    1974-01-01

    Fifteen distinct components can be identified in the scalp recorded average evoked potential to an abrupt auditory stimulus. The early components occurring in the first 8 msec after a stimulus represent the activation of the cochlea and the auditory nuclei of the brainstem. The middle latency components occurring between 8 and 50 msec after the stimulus probably represent activation of both auditory thalamus and cortex but can be seriously contaminated by concurrent scalp muscle reflex potentials. The longer latency components occurring between 50 and 300 msec after the stimulus are maximally recorded over fronto-central scalp regions and seem to represent widespread activation of frontal cortex.

  12. Synthesis and characterization of EADAM: a selective radioligand for mapping the brain serotonin transporters by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jarkas, Nachwa [Department of Radiology, Division of Radiological Sciences, Emory University, Atlanta, GA 30322 (United States); McConathy, Jonathan [Department of Radiology, Division of Radiological Sciences, Emory University, Atlanta, GA 30322 (United States); Department of Psychiatry and Behavior Sciences, Emory University, Atlanta, GA 30322 (United States); Votaw, John R. [Department of Radiology, Division of Radiological Sciences, Emory University, Atlanta, GA 30322 (United States); Voll, Ronald J. [Department of Radiology, Division of Radiological Sciences, Emory University, Atlanta, GA 30322 (United States); Malveaux, Eugene [Department of Radiology, Division of Radiological Sciences, Emory University, Atlanta, GA 30322 (United States); Camp, Vernon M. [Department of Radiology, Division of Radiological Sciences, Emory University, Atlanta, GA 30322 (United States); Williams, Larry [Department of Radiology, Division of Radiological Sciences, Emory University, Atlanta, GA 30322 (United States); Goodman, Robin R. [Department of Radiology, Division of Radiological Sciences, Emory University, Atlanta, GA 30322 (United States); Kilts, Clinton D. [Department of Psychiatry and Behavior Sciences, Emory University, Atlanta, GA 30322 (United States); Goodman, Mark M. [Department of Radiology, Division of Radiological Sciences, Emory University, Atlanta, GA 30322 (United States) and Department of Psychiatry and Behavior Sciences, Emory University, Atlanta, GA 30322 (United States)]. E-mail: mgoodma@emory.edu

    2005-01-01

    [{sup 11}C]N,N-Dimethyl-2-(2'-amino-4'-ethylphenylthio)benzylamine ([{sup 11}C]EADAM) was synthesized in the development of a serotonin transporter (SERT) imaging ligand for positron emission tomography (PET). The methods of ligand synthesis, results of in vitro characterization, {sup 11}C labeling and in vivo micro-PET imaging studies of [{sup 11}C]EADAM in cynomolgus monkey brain are described. {sup 11}C was introduced into N,N-dimethyl-2-(2'-amino-4'-ethylphenylthio)benzylamine () by alkylation of N-methyl-2-(2'-amino-4'-ethylphenylthio)benzylamine () in 32% radiochemical yield (end of bombardment [EOB], decay-corrected from [{sup 11}C]methyl iodide). Competition binding assays in cells stably expressing the transfected human dopamine transporter (DAT), SERT and norepinephrine transporter (NET) labeled with [{sup 3}H]WIN 35428 or [{sup 125}I]RTI-55, [{sup 3}H]citalopram and [{sup 3}H]nisoxetine, respectively, indicated the following order of SERT affinity: ADAM>EADAM>>fluvoxamine. The affinity of EADAM for DAT and NET was 500- and >1000-fold lower, respectively, than for SERT. Micro-PET brain imaging studies in a cynomolgus monkey demonstrated high [{sup 11}C]EADAM uptake in the striatum, thalamus and brainstem. [{sup 11}C]EADAM uptake in these brain regions peaked in less than 60 min following administration of [{sup 11}C]EADAM. The tissue-to-cerebellum ratios of the striatum, thalamus and brainstem were 1.67, 1.71 and 1.63, respectively, at 120 min postinjection of [{sup 11}C]EADAM. Analysis of monkey arterial plasma samples using high-pressure liquid chromatography determined there was no detectable formation of lipophilic radiolabeled metabolites capable of entering the brain. In a displacement experiment with citalopram in a cynomolgus monkey, radioactivity in the striatum, thalamus and brainstem was displaced 20-60 min after administration of citalopram. In a blocking experiment with citalopram in a cynomolgus monkey

  13. <報告>頭部外傷により小児失語症を呈した1例の長期経過

    OpenAIRE

    玉井,ふみ; 徳永,要二

    1996-01-01

    A longitudinal study of a case of aphasia acquired in childhood was reported. The patient was a 27-year-old right-handed man who had suffered a traumatic brain injury caused by a serious traumatic fall at 11 years of age. Surgery was performed to remove an epidural hematoma immediately. He remained in a coma for four months following the accident. MRI revealed extensive lesions extending across the parietal, temporal, and occipital lobes, basal ganglia and thalamus in the left hemisphere. The...

  14. Cerebral hemorrhagic infarction after radiation for pituitary adenoma

    Energy Technology Data Exchange (ETDEWEB)

    Ogaki, Satoko; Suzuki, Masatsune; Shimano, Hitoshi; Toyoshima, Hideo; Sone, Hirohito; Okuda, Yukichi; Yamada, Nobuhiro [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Suzuki, Seiji; Suzuki, Hiroaki [National Hospital Tokyo Disaster Medical Center, Tachikawa (Japan)

    2002-10-01

    We report a case of cerebral hemorrhagic infarction after radiation for pituitary adenoma. A 55-year-old woman was hospitalized to check for aldosteronism, post-operative pituitary function, and recurrence of thyroid cancer. She had short-term memory disturbance beginning two months prior to admission. Brain MRI showed a T1 and T2 high intensity lesion of her left anterolateral thalamus. Brain MRA revealed a narrowing in her left middle cerebral artery. The abnormal brain lesion was diagnosed as cerebral hemorrhagic infarction. She had received radiation therapy for pituitary adenoma 20 years earlier. It was considered that her cerebral hemorrhagic infarction was caused by radiation therapy. (author)

  15. Cockayne syndrome: MRI correlates of hypomyelination.

    Science.gov (United States)

    Dabbagh, O; Swaiman, K F

    1988-01-01

    Two siblings with Cockayne syndrome are reported who had most of the stigmata characteristic of the syndrome as it was initially described in 1936. Unusual findings are emphasized, such as the early onset of cataracts and the early detection of peripheral neuropathy. The previously reported autopsy abnormalities in this condition are correlated with the present magnetic resonance imaging findings of mild ventricular enlargement and delay in myelination of the cerebrum and cerebellum. Properly myelinated structures included the basal ganglia, thalamus, internal capsule, splenium, and genu of the corpus callosum.

  16. [{sup 123}I]-3-Iodcytisin as possible radiotracer for the imaging of nicotinic acetylcholine receptors using single photon emission computer tomography; [{sup 123}I]-3-Iodcytisin als moeglicher Radiotracer fuer die Darstellung der nikotinergen Acetylcholin Rezeptoren mittels Single-Photon-Emissions-Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Paulik, Dagmar Julia

    2015-03-06

    For the synthesis of [{sup 123}I]-3-Iodcytisin as possible radiotracer for the imaging of nicotinic acetylcholine (nACh) receptors using SPECT two different technologies were used: the radio-iodination with iodogen and the radio-iodination with nitric acid. The latter one showed higher efficiency. The radiotracer will allow to detect degenerative processes and other nACh-depending diseases in the brain (Alzheimer, Parkinson) and to observe the progress. The autoradiography is aimed to the imaging of the nACh receptors in the brain bypassing the brain-blood barrier. The highest activity was measured in the thalamus of mice and rat brains.

  17. Quantification of [11C]yohimbine binding to α2 adrenoceptors in rat brain in vivo

    DEFF Research Database (Denmark)

    Phan, Jenny-Ann; Landau, Anne M.; Wong, Dean F.

    2015-01-01

    tomography (PET) recordings were applied to five Sprague Dawley rats at baseline, followed by acute amphetamine administration (2 mg/kg) to induce elevation of the endogenous level of noradrenaline. The volume of distribution (VT) of [11C]yohimbine was obtained using Logan plot with arterial plasma input...... challenge with amphetamine induced a significant decline of [11C]yohimbine BPND of ∼38% in all volumes of interest. The BPND was greatest in the thalamus and striatum, followed in descending order by, frontal cortex, pons, and cerebellum. The experimental data demonstrate that [11C]yohimbine binding...

  18. Loss of function of Slc20a2 associated with familial idiopathic basal ganglia calcification in humans causes brain calcifications in mice

    DEFF Research Database (Denmark)

    Jensen, Nina; Daa Schrøder, Henrik; Kildall Hejbøl, Eva

    2013-01-01

    Familial idiopathic basal ganglia calcification (FIBGC) is a neurodegenerative disorder with neuropsychiatric and motor symptoms. Deleterious mutations in SLC20A2, encoding the type III sodium-dependent phosphate transporter 2 (PiT2), were recently linked to FIBGC in almost 50 % of the families r...... reported worldwide. Here, we show that knockout of Slc20a2 in mice causes calcifications in the thalamus, basal ganglia, and cortex, demonstrating that reduced PiT2 expression alone can cause brain calcifications....

  19. Medial thalamic 18-FDG uptake following inescapable shock correlates with subsequent learned helpless behavior

    Energy Technology Data Exchange (ETDEWEB)

    Mirrione,M.M.; Mirrione, M.M.; Schulz, D.; Dewey, S.L.; Henn, F.A.

    2009-12-06

    The learned helplessness paradigm has been repeatedly shown to correlate with neurobiological aspects of depression in humans. In this model, rodents are exposed inescapable foot-shock in order to reveal susceptibility to escape deficit, defined as 'learned helplessness' (LH). Few methods are available to probe the neurobiological aspects underlying the differences in susceptibility in the living animal, thus far being limited to studies examining regional neurochemical changes with microdialysis. With the widespread implementation of small animal neuroimaging methods, including positron emission tomography (PET), it is now possible to explore the living brain on a systems level to define regional changes that may correlate with vulnerability to stress. In this study, 12 wild type Sprague-Dawley rats were exposed to 40 minutes of inescapable foot-shock followed by metabolic imaging using 2-deoxy-2[{sup 18}F]fluoro-D-glucose (18-FDG) 1 hour later. The escape test was performed on these rats 48 hours later (to accommodate radiotracer decay), where they were given the opportunity to press a lever to shut off the shock. A region of interest (ROI) analysis was used to investigate potential correlations (Pearson Regression Coefficients) between regional 18-FDG uptake following inescapable shock and subsequent learned helpless behavior (time to finish the test; number of successful lever presses within 20 seconds of shock onset). ROI analysis revealed a significant positive correlation between time to finish and 18-FDG uptake, and a negative correlation between lever presses and uptake, in the medial thalamic area (p=0.033, p=0.036). This ROI included the paraventricular thalamus, mediodorsal thalamus, and the habenula. In an effort to account for possible spillover artifact, the posterior thalamic area (including ventral medial and lateral portions) was also evaluated but did not reveal significant correlations (p=0.870, p=0.897). No other significant

  20. Calcitonin gene-related peptide modulates heat nociception in the human brain - An fMRI study in healthy volunteers

    DEFF Research Database (Denmark)

    Asghar, Mohammad Sohail; Becerra, Lino; Larsson, Henrik B.W.

    2016-01-01

    blood-oxygenation-level-dependent (BOLD) signals in the brain by functional MRI after infusion of CGRP in a double-blind placebo-controlled crossover study of 27 healthy volunteers. BOLD-signals were recorded in response to noxious heat stimuli in the V1-area of the trigeminal nerve. In addition, we...... measured BOLD-signals after injection of sumatriptan (5-HT1B/1D antagonist). Results: Brain activation to noxious heat stimuli following CGRP infusion compared to baseline resulted in increased BOLD-signal in insula and brainstem, and decreased BOLD-signal in the caudate nuclei, thalamus and cingulate...

  1. Altered structural connectivity of cortico-striato-pallido-thalamic networks in Gilles de la Tourette syndrome.

    Science.gov (United States)

    Worbe, Yulia; Marrakchi-Kacem, Linda; Lecomte, Sophie; Valabregue, Romain; Poupon, Fabrice; Guevara, Pamela; Tucholka, Alan; Mangin, Jean-François; Vidailhet, Marie; Lehericy, Stephane; Hartmann, Andreas; Poupon, Cyril

    2015-02-01

    Gilles de la Tourette syndrome is a childhood-onset syndrome characterized by the presence and persistence of motor and vocal tics. A dysfunction of cortico-striato-pallido-thalamo-cortical networks in this syndrome has been supported by convergent data from neuro-pathological, electrophysiological as well as structural and functional neuroimaging studies. Here, we addressed the question of structural integration of cortico-striato-pallido-thalamo-cortical networks in Gilles de la Tourette syndrome. We specifically tested the hypothesis that deviant brain development in Gilles de la Tourette syndrome could affect structural connectivity within the input and output basal ganglia structures and thalamus. To this aim, we acquired data on 49 adult patients and 28 gender and age-matched control subjects on a 3 T magnetic resonance imaging scanner. We used and further implemented streamline probabilistic tractography algorithms that allowed us to quantify the structural integration of cortico-striato-pallido-thalamo-cortical networks. To further investigate the microstructure of white matter in patients with Gilles de la Tourette syndrome, we also evaluated fractional anisotropy and radial diffusivity in these pathways, which are both sensitive to axonal package and to myelin ensheathment. In patients with Gilles de la Tourette syndrome compared to control subjects, we found white matter abnormalities in neuronal pathways connecting the cerebral cortex, the basal ganglia and the thalamus. Specifically, striatum and thalamus had abnormally enhanced structural connectivity with primary motor and sensory cortices, as well as paracentral lobule, supplementary motor area and parietal cortices. This enhanced connectivity of motor cortex positively correlated with severity of tics measured by the Yale Global Tics Severity Scale and was not influenced by current medication status, age or gender of patients. Independently of the severity of tics, lateral and medial orbito

  2. Attentional effects in the visual pathways

    DEFF Research Database (Denmark)

    Bundesen, Claus; Larsen, Axel; Kyllingsbæk, Søren

    2002-01-01

    nucleus. Frontal activations were found in a region that seems implicated in visual short-term memory (posterior parts of the superior sulcus and the middle gyrus). The reverse, color-shape comparison showed bilateral increases in rCBF in the anterior cingulate gyri, superior frontal gyri, and superior...... and middle temporal gyri. The attentional effects found by the shape-color comparison in the thalamus and the primary visual cortex may have been generated by feedback signals preserving visual representations of selected stimuli in short-term memory....

  3. Ipsilateral sensory disturbances in Complex Regional Pain Syndrome (CRPS)

    DEFF Research Database (Denmark)

    Knudsen, Lone

    a disturbance in central nociceptive pathways processing input from hemilateral body sites. However, it may also be consistent with referred pain and cortical reorganization. Thus, it is important to assess whether sensory disturbances spread to ipsilateral body sites other than the forehead. The aim...... hyperalgesia to sharpness were not related to age, pain intensity, or pain duration. 2 Conclusions: The findings suggest the presence of heightened excitability in nociceptive pathways in CRPS, particularly those that provide hemilateral input, perhaps due to disturbances in pain control from thalamus...

  4. Preterm birth and structural brain alterations in early adulthood

    Directory of Open Access Journals (Sweden)

    Chiara Nosarti

    2014-01-01

    Full Text Available Alterations in cortical development and impaired neurodevelopmental outcomes have been described following very preterm (VPT birth in childhood and adolescence, but only a few studies to date have investigated grey matter (GM and white matter (WM maturation in VPT samples in early adult life. Using voxel-based morphometry (VBM we studied regional GM and WM volumes in 68 VPT-born individuals (mean gestational age 30 weeks and 43 term-born controls aged 19–20 years, and their association with cognitive outcomes (Hayling Sentence Completion Test, Controlled Oral Word Association Test, Visual Reproduction test of the Wechsler Memory Scale-Revised and gestational age. Structural MRI data were obtained with a 1.5 Tesla system and analysed using the VBM8 toolbox in SPM8 with a customized study-specific template. Similarly to results obtained at adolescent assessment, VPT young adults compared to controls demonstrated reduced GM volume in temporal, frontal, insular and occipital areas, thalamus, caudate nucleus and putamen. Increases in GM volume were noted in medial/anterior frontal gyrus. Smaller subcortical WM volume in the VPT group was observed in temporal, parietal and frontal regions, and in a cluster centred on posterior corpus callosum/thalamus/fornix. Larger subcortical WM volume was found predominantly in posterior brain regions, in areas beneath the parahippocampal and occipital gyri and in cerebellum. Gestational age was associated with GM and WM volumes in areas where VPT individuals demonstrated GM and WM volumetric alterations, especially in temporal, parietal and occipital regions. VPT participants scored lower than controls on measures of IQ, executive function and non-verbal memory. When investigating GM and WM alterations and cognitive outcome scores, subcortical WM volume in an area beneath the left inferior frontal gyrus accounted for 14% of the variance of full-scale IQ (F = 12.9, p < 0.0001. WM volume in posterior corpus

  5. A viscoelastic analysis of the P56 mouse brain under large-deformation dynamic indentation.

    Science.gov (United States)

    MacManus, David B; Pierrat, Baptiste; Murphy, Jeremiah G; Gilchrist, Michael D

    2017-01-15

    The brain is a complex organ made up of many different functional and structural regions consisting of different types of cells such as neurons and glia, as well as complex anatomical geometries. It is hypothesized that the different regions of the brain exhibit significantly different mechanical properties which may be attributed to the diversity of cells within individual brain regions. The regional viscoelastic properties of P56 mouse brain tissue, up to 70μm displacement, are presented and discussed in the context of traumatic brain injury, particularly how the different regions of the brain respond to mechanical loads. Force-relaxation data obtained from micro-indentation measurements were fit to both linear and quasi-linear viscoelastic models to determine the time and frequency domain viscoelastic response of the pons, cortex, medulla oblongata, cerebellum, and thalamus. The damping ratio of each region was also determined. Each region was found to have a unique mechanical response to the applied displacement, with the pons and thalamus exhibiting the largest and smallest force-response, respectively. All brain regions appear to have an optimal frequency for the dissipation of energies which lies between 1 and 10Hz. We present the first mechanical characterization of the viscoelastic response for different regions of mouse brain. Force-relaxation tests are performed under large strain dynamic micro-indentation, and viscoelastic models are used subsequently, providing time-dependent mechanical properties of brain tissue under loading conditions comparable to what is experienced in TBI. The unique mechanical properties of different brain regions are highlighted, with substantial variations in the viscoelastic properties and damping ratio of each region. Cortex and pons were the stiffest regions, while the thalamus and medulla were most compliant. The cerebellum and thalamus had highest damping ratio values and those of the medulla were lowest. The reported

  6. Lethal subarachnoid bleeding under immunosuppressive therapy due to mycotic arteritis

    Energy Technology Data Exchange (ETDEWEB)

    Weigel, S.; Kloska, S.; Freund, M. [Dept. of Clinical Radiology, Univ. Hospital of Muenster, Muenster (Germany); Kehl, H.G. [Dept. of Pediatric Cardiology, Univ. Hospital of Muenster, Muenster (Germany)

    2003-12-01

    A subarachnoid haemorrhage (SAH) occurred 67 days after cardiac transplantation in 10-year-old girl with consecutive immunocompromising therapy. Neither digital subtraction angiography (DSA) nor computed tomographic angiography showed signs of intracranial vascular malformations. One month before the lethal SAH occurred, she had developed arterial hypertension and attacks of severe headache with cerebrospinal fluid (CSF) pleocytosis while CT scans showed an infarct of the left thalamus. Pathologic findings established the rare diagnosis of SAH due to aspergillosis-related mycotic arteritis. Imaging characteristics are presented. (orig.)

  7. MRI in tick-borne encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Alkadhi, H.; Kollias, S.S. [Institute of Neuroradiology, University Hospital of Zurich (Switzerland)

    2000-10-01

    The tick-borne encephalitis (TBE) virus gives rise to epidemic encephalitis. Mild forms usually manifest as influenza-like episodes or are clinically silent. MRI is usually normal in TBE. We describe severe TBE in a patient who presented with fever and altered mental status after a tick bite and a specific antibody response to TBE. MRI revealed pronounced signal abnormalities in the basal ganglia and thalamus, without contrast enhancement. These findings coincide well with neuropathological studies of severe nerve cell degeneration with inflammatory cell infiltrates, neuronophagia and reactive astrocytosis in the deep grey matter. We review the literature and discuss the relevant differential diagnosis. (orig.)

  8. Somatosensory evoked response: application in neurology

    Directory of Open Access Journals (Sweden)

    Carlos A. M. Guerreiro

    1982-03-01

    Full Text Available One technique used for short-latency somatosensory evoked response (SER is described. SER following nerve stimulation is a unique non-invasive, clinical test used to evaluate the somatosensory pathways. It tests the physiological function of the median nerve, the brachial plexus, the C6-7 cervical roots, cervical spinal cord, the cuneate nuclei, the medial lemniscus, the thalamus, and the contralateral sensory cortex. It has been shown to be a reliable and useful clinical test partiicularly in multiple sclerosis and comatose patients. The promising technique of SER following peroneal nerve stimulation is mentioned.

  9. Effects of donepezil on behavioural manifestations of thalamic infarction: a single case observation

    Directory of Open Access Journals (Sweden)

    Rodrigo eRiveros

    2011-03-01

    Full Text Available Objective: To examine the effect of donepezil for the treatment of cognitive and behavioural disorders associated with thalamic lesions in a 45 years old male who suffered an infarct in the left thalamus. Background: Recent studies suggest that donepezil may improve executive functions impairments due to subcortical ischemic lesionsMethod: The crossover effects of donepezil were analyzed in a single case of thalamic infarction with cognitive and behavioural alterations. Results: Significant behavioural modifications related to improved performances in executive functions were observed with the treatment. Conclusions: The results suggest that donepezil may have significant effect on executive functions that can alter behavioural outcomes after thalamic infarctions

  10. Altered 13C glucose metabolism in the cortico-striato-thalamo-cortical loop in the MK-801 rat model of schizophrenia

    DEFF Research Database (Denmark)

    Eyjolfsson, Elvar M; Nilsen, Linn Hege; Kondziella, Daniel

    2011-01-01

    and on day 6, they also received an injection of [1-(13)C]glucose. Extracts of frontal cortex (FCX), parietal and temporal cortex (PTCX), thalamus, striatum, nucleus accumbens (NAc), and hippocampus were analyzed using (13)C nuclear magnetic resonance spectroscopy, high-performance liquid chromatography......, and gas chromatography-mass spectrometry. A pronounced reduction in glycolysis was found only in PTCX, in which (13)C labeling of glucose, lactate, and alanine was decreased. (13)C enrichment in lactate, however, was reduced in all areas investigated. The largest reductions in glutamate labeling were...

  11. Neuromyelitis optica and Wernicke encephalopathy share the similar imagings, any correlations?

    Directory of Open Access Journals (Sweden)

    Jing Yang

    2016-06-01

    Full Text Available Two cases with similar brain imaging findings were reported. Both brain MRIs were characterized by abnormal signal intensities in thalamus, surrounding third ventricle, periaqueductal areas and posteromedial thalami. Through clinical observation and a series of auxiliary examinations, one patient was diagnosed as Wernicke encephalopathy (WE and the other as neuromyelitis optica (NMO. Although WE and NMO are totally different diseases entity, but similar lesions area aroused hypothesis that potential correlations may exist between these two diseases. Astrocytes may be the target cells connecting these two diseases. Potential benefit of thiamine supplementary therapy is suggested for NMO treatment.

  12. Bilateral internal carotid artery agenesis with artery compression of the brain parenchyma.

    Science.gov (United States)

    Sun, Jihong; Jiang, Dingyao; Zhang, Shizheng

    2008-09-15

    Bilateral internal carotid artery (ICA) agenesis is an extremely rare congenital anomaly. The most common type of collateral circulation is developed through the circle of Willis via the basilar and posterior communicating arteries. Both anterior circulations are usually supplied by enlarged posterior communicating arteries (PCOMs). We present an unusual case of bilateral ICA agenesis, which is associated with dolichoectatic left PCOM and left posterior cerebral artery (PCA) compression of left basal ganglia and thalamus. These complex cerebral and vascular anomalies can be noninvasively revealed and evaluated by CT and MR.

  13. Benzodiazepine receptor quantification in vivo in humans using [11C]flumazenil and PET

    DEFF Research Database (Denmark)

    Lassen, N A; Bartenstein, P A; Lammertsma, A A

    1995-01-01

    Carbon-11-labeled flumazenil combined with positron emission tomography (PET) was used to measure the concentration (Bmax) of the benzodiazepine (Bz) receptor in the brain and its equilibrium dissociation constant (KD) for flumazenil in five normal subjects. The steady-state approach was used...... (60 min instead of 120 min) it was preferred. The five subjects had a mean KD value of 12 nM/L of water and Bmax values of the grey matter ranging from 39 +/- 11 in thalamus to 120 +/- 14 nM/L of brain in occipital cortex. Most previous studies have been based on the pseudoequilibrium approach using...

  14. Barrels XXVII meeting report: Barrels in the monument city.

    Science.gov (United States)

    Bajnath, Adesh; Chu, Philip; Steger, Robert; Brumberg, Joshua C

    2015-01-01

    The 27th annual Barrels meeting highlighted the latest advances in this rapidly growing field. The Barrels meeting annually focuses on the role of the posterior medial thalamus in somatosensation, dendritic processing, and the cortical dynamics involved during touch perception. Speakers utilized diverse molecular, physiological, computational techniques to understand the development, sensory processing, and motor commands that are involved with the rodent mystacial vibrissae. The meeting was held Thursday, 13 November through Friday, 14 November 2014 on the Homewood campus of Johns Hopkins University, Baltimore, MD.

  15. Hydranencephaly in Neonates

    Directory of Open Access Journals (Sweden)

    Jeng-Dau Tsai

    2008-08-01

    Full Text Available Hydranencephaly is characterized by severe dysgenesis of the cerebral hemispheres, with relative preservation of the thalamus, cerebellum and brainstem. Modern neurological imaging techniques have demonstrated that the affected regions are usually localized within the territories of the middle cerebral arteries. Evoked potentials have confirmed the imaging findings. This article reports on two neonates with hydranencephaly who presented with normal appearance. Neurological images were characterized by marked reduction of the total brain cortex, which was replaced by fluid. Evoked potentials demonstrated preserved auditory evoked potentials but a total absence of visual evoked potentials. These diagnostic techniques provided efficient and precise information concerning the extent of intracranial dysgenesis.

  16. Subcortical connections of an 'oculomotor' region in the ventral bank of the anterior ectosylvian sulcus in the cat.

    Science.gov (United States)

    Tamai, Y; Miyashita, E

    1989-12-01

    Subcortical connections of an 'oculomotor' region in the ventral bank of the anterior ectosylvian sulcus (AESo), where eye movements were evoked by intracortical microstimulation, were studied in cats using a wheatgerm agglutinin horseradish peroxidase (WGA-HRP) tracing method. Following injection of WGA-HRP into the AESo, both anterogradely-labeled terminals and retrogradely-labeled cells were found with the highest concentration in the suprageniculate nucleus and the medial zone of the lateroposterior nucleus of the thalamus. In the brainstem, anterogradely-labeled terminals were found in the superior colliculus, the pontine reticular formation, the pontine tegmental reticular formation and the pontine nuclei.

  17. Effect of intranasally administered insulin on cerebral blood flow and perfusion

    DEFF Research Database (Denmark)

    Akintola, Abimbola A.; van Opstal, Anna M.; Westendorp, Rudi G.

    2017-01-01

    (40IU) on cerebral blood flow (CBF) and perfusion in older (60-69 years, n=11) and younger (20-26 years, n=8) adults. Changes in CBF through the major cerebropetal arteries were assessed via phase contrast MR-angiography, and regional cortical tissue perfusion via pseudo-continuous arterial spin.......28±6.75 mL/100g/min versus 63.31±6.84 mL/100g/min, P=0.003). Thus, intranasal insulin improved tissue perfusion of the occipital cortical brain region and the thalamus in older adults....

  18. Changes in the Papez Circuit in early stages of Alzheimer's Disease

    OpenAIRE

    García-Polo, Pablo; Pajares, Gonzalo; Hernández Tamames, J.A.; Alfayate, E.; Frank, A.; Alvarez Linera, Juan

    2011-01-01

    Alzheimer's disease (AD) is the most common cause of demenMa. Neuronal and synapMc losses occur iniMally and predominantly in the medial temporal lobe structures including hippocampus, amygdala and thalamus, structures that belong to the Papez circuit. The integrity of the connecMons amongst them is essenMal for episodic memory, which is specifically impaired in AD. For this reason we have invesMgated the degeneraMon paRern of subcorMcal structures and its relaMon to early stages of AD, i.e. ...

  19. Experiment list: SRX019342 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available SRX019342 hg19 Histone H3K4me3 Neural Prefrontal Cortex MeSH Description=The rostra...fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...K4me3 NeuN+ rep2 #11.2 source_name=prefrontal cortex || population=NeuN+ || age=69 || chip antibody=H3K4me3 ...|| cell type=neurons from prefrontal cortex http://dbarchive.biosciencedbc.jp/kyu

  20. Experiment list: SRX019344 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available SRX019344 hg19 Histone H3K4me3 Neural Prefrontal Cortex MeSH Description=The rostra...fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from num...K4me3 NeuN- rep1 #11n source_name=prefrontal cortex || population=NeuN- || age=69 || chip antibody=H3K4me3 |...| cell type=neurons from prefrontal cortex http://dbarchive.biosciencedbc.jp/kyus

  1. Convergence spasm due to aquaporin-positive neuromyelitis optica spectrum disorder

    Directory of Open Access Journals (Sweden)

    Pınar Özçelik

    2017-06-01

    Full Text Available A female 27 presented with nausea and diplopia for 1 week. On examination she had normal vertical gaze but would develop convergence with miosis whenever she made horizontal saccades. Pupils were 6 mm and unreactive to light. MRI showed extensive hyperintensity in the dorsal midbrain and thalamus. Spinal MRI and CSF were both normal. Serum aquaporin-4-antibody was positive. She was treated with steroids and plasmapheresis and after 3 months convergence spasm resolved but pupils remained unreactive. Neuromyelitis optica often presents with brainstem signs, rarely a dorsal midbrain syndrome. Convergence spasm is occasionally of organic neurologic origin.

  2. 350-μm side-view optical probe for imaging the murine brain in vivo from the cortex to the hypothalamus

    Science.gov (United States)

    Kim, Jun Ki; Choi, Jin Woo; Yun, Seok Hyun

    2013-05-01

    Miniature endoscopic probes offer a solution for deep brain imaging by overcoming the limited depth of intravital microscopy. We describe a small-diameter (350 μm) graded-index optical probe with a side-view design for in vivo cellular imaging of the mammalian brain. The side-view probe provides a unique view of the vertical network of neurons and penetrating blood vessels. At a given insertion site, the translational and rotational scanning of the probe provides access to a large tissue area (>) across the cortex, hippocampus, thalamus, and hypothalamus.

  3. Touch me not

    Directory of Open Access Journals (Sweden)

    Paras Karmacharya

    2014-02-01

    Full Text Available Central Poststroke Pain syndrome (CPSP can occur due to disruption of the somatosensory pathways of the brain at any level such as the thalamus, medulla, or cerebral cortex. It is characterized by sensory abnormalities and hyperesthesia in the part of the body correlating to the central lesion. The treatment of this pain syndrome is often difficult, and it does not usually respond to traditional analgesics. The first line of treatment is drugs aimed at lowering neuronal hyperexcitability, for example, amitriptyline or lamotrigine, with gabapentin considered a second line.

  4. Location of lacunar infarcts correlates with cognition in a sample of non-disabled subjects with age-related white-matter changes: the LADIS study

    DEFF Research Database (Denmark)

    Benisty, S; Gouw, A A; Porcher, R

    2009-01-01

    in the following areas: lobar white matter, putamen/pallidum, thalamus, caudate nucleus, internal/external capsule, infratentorial areas. An analysis of covariance was performed after adjustment for possible confounders. RESULTS: Among 633 subjects, 47% had at least one lacune (31% at least one within basal...... a significant negative association between the presence of lacunes in putamen/pallidum and the memory compound Z score (beta = -0.13; p = 0.038). By contrast, no significant negative association was found between cognitive parameters and the presence of lacunes in internal capsule, lobar white matter...

  5. Dramatic response to levetiracetam in post-ischaemic Holmes’ tremor

    Science.gov (United States)

    Striano, P; Elefante, Andrea; Coppola, Antonietta; Tortora, Fabio; Zara, Federico; Minetti, Carlo

    2009-01-01

    Holmes’ tremor refers to an unusual combination of rest, postural and kinetic tremor of extremities. Common causes of Holmes’ tremor include stroke, trauma, vascular malformations and multiple sclerosis, with lesions involving the thalamus, brain stem or cerebellum. Although some drugs (eg, levodopa and dopaminergic drugs, clonazepam and propranolol) have been occasionally reported to give some benefit, medical treatment of Holmes’ tremor is unsatisfactory, and many patients require thalamic surgery to achieve satisfactory control. We report a patient in whom post-ischaemic Holmes’ tremor dramatically responded to levetiracetam treatment. PMID:21686707

  6. Nasitrema sp.-associated encephalitis in a striped dolphin (Stenella coeruleoalba) stranded in the Gulf of Mexico

    Science.gov (United States)

    O'Shea, Thomas J.; Homer, Bruce L.; Greiner, Ellis C.; Layton, A. William

    1991-01-01

    An immature female striped dolphin (Stenella coeruleoalba) found dead on a northwestern Florida beach in 1988 exhibited severe inflammation bilaterally in the dorsal and mid-thalamus in association with adult trematodes (Nasitrema sp.) and trematode eggs. Numerous specimens of Nasitrema sp. also were present in the pterygoid sinuses. Pneumonia in association with a heavy growth of Vibrio damsela was observed also. This report confirms the occurrence of Nasitrema sp.-associated encephalitis in striped dolphins and in small cetaceans from the Gulf of Mexico.

  7. Brain Tumor-Associated Psychosis and Spirituality—A Case Report

    Directory of Open Access Journals (Sweden)

    Lars Levi Dutschke

    2017-11-01

    Full Text Available This case report describes a patient with a dysembryogenic neuroepithelial tumor localized in the posterior thalamus and internal capsule, which presented with psychosis including religiously determined severe self-mutilation, auditory hallucinations, and rituals. The patient’s history includes periodic religiousness over decades of her life suggesting that spirituality in this case might be a symptom of tumor progression. Our case reports on the topology-related effect of lesions on different brain networks involved in the phenomenology of the patient’s psychotic symptoms.

  8. Diffusion MRI findings in patients with extensive and minimal post-concussion symptoms after mTBI and healthy controls - a cross sectional study

    DEFF Research Database (Denmark)

    Næss-Schmidt, Erhard Trillingsgaard; Blicher, Jakob Udby; Tietze, Anna

    2017-01-01

    PRIMARY OBJECTIVES: We hypothesized that the microstructure of the corpus callosum, thalamus and hippocampus, as measured with diffusion and Mean of the Kurtosis Tensor (MKT) MRI, differs between healthy subjects and patients with extensive and minimal post-concussion symptoms (PCS) and that MKT...... AND PROCEDURES: Diffusion MRI was obtained in 25 patients with extensive PCS and in 25 patients with minimal PCS as measured by the Rivermead Post-concussion Symptoms Questionnaire. The patients were matched on age, sex and time since accident. Data from an external healthy control group (n = 27) was included...

  9. Analysis of transcriptional initiation and translatability of brain-derived neurotrophic factor mRNAs in the rat brain.

    Science.gov (United States)

    Timmusk, T; Persson, H; Metsis, M

    1994-08-15

    The rat brain-derived neurotrophic factor (BDNF) gene consists of four 5' exons linked to separate promoters and one 3' exon encoding the prepro-BDNF protein. In the present study, using RNase protection analysis, we show that the same major transcription initiation sites are used for each BDNF exon mRNA in different brain regions and that in addition to hippocampus and cerebral cortex, kainate differentially induces the expression of BDNF exon mRNAs in thalamus, cerebellum and striatum. The 4.2 kb transcripts, are less enriched in the polysomal fraction of rat brain than the shorter 1.6 kb transcripts suggesting their translational discrimination.

  10. Positron emission tomography assessment of effects of benzodiazepines on regional glucose metabolic rate in patients with anxiety disorder

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    Buchsbaum, M.S.; Wu, J.; Haier, R.; Hazlett, E.; Ball, R.; Katz, M.; Sokolski, K.; Lagunas-Solar, M.; Langer, D.

    1987-06-22

    Patients with generalized anxiety disorder (n = 18) entered a 21-day, double-blind, placebo-controlled random assignment trial of clorazepate. Positron emission tomography with YF-deoxyglucose was carried out before and after treatment. Decreases in glucose metabolic rate in visual cortex and relative increases in the basal ganglia and thalamus were found. A correlation between regional changes in metabolic rate and regional benzodiazepine receptor binding density from other human autopsy studies was observed; brain regions highest in receptor density showed the greatest decrease in rate.

  11. A Bayesian Generative Model for Surface Template Estimation

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    Jun Ma

    2010-01-01

    Full Text Available 3D surfaces are important geometric models for many objects of interest in image analysis and Computational Anatomy. In this paper, we describe a Bayesian inference scheme for estimating a template surface from a set of observed surface data. In order to achieve this, we use the geodesic shooting approach to construct a statistical model for the generation and the observations of random surfaces. We develop a mode approximation EM algorithm to infer the maximum a posteriori estimation of initial momentum μ, which determines the template surface. Experimental results of caudate, thalamus, and hippocampus data are presented.

  12. Rapid treatment-induced brain changes in pediatric CRPS.

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    Erpelding, Nathalie; Simons, Laura; Lebel, Alyssa; Serrano, Paul; Pielech, Melissa; Prabhu, Sanjay; Becerra, Lino; Borsook, David

    2016-03-01

    To date, brain structure and function changes in children with complex regional pain syndrome (CRPS) as a result of disease and treatment remain unknown. Here, we investigated (a) gray matter (GM) differences between patients with CRPS and healthy controls and (b) GM and functional connectivity (FC) changes in patients following intensive interdisciplinary psychophysical pain treatment. Twenty-three patients (13 females, 9 males; average age ± SD = 13.3 ± 2.5 years) and 21 healthy sex- and age-matched controls underwent magnetic resonance imaging. Compared to controls, patients had reduced GM in the primary motor cortex, premotor cortex, supplementary motor area, midcingulate cortex, orbitofrontal cortex, dorsolateral prefrontal cortex (dlPFC), posterior cingulate cortex, precuneus, basal ganglia, thalamus, and hippocampus. Following treatment, patients had increased GM in the dlPFC, thalamus, basal ganglia, amygdala, and hippocampus, and enhanced FC between the dlPFC and the periaqueductal gray, two regions involved in descending pain modulation. Accordingly, our results provide novel evidence for GM abnormalities in sensory, motor, emotional, cognitive, and pain modulatory regions in children with CRPS. Furthermore, this is the first study to demonstrate rapid treatment-induced GM and FC changes in areas implicated in sensation, emotion, cognition, and pain modulation.

  13. Functional disconnection of thalamic and cerebellar dentate nucleus networks in progressive supranuclear palsy and corticobasal syndrome.

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    Upadhyay, Neeraj; Suppa, Antonio; Piattella, Maria Cristina; Giannì, Costanza; Bologna, Matteo; Di Stasio, Flavio; Petsas, Nikolaos; Tona, Francesca; Fabbrini, Giovanni; Berardelli, Alfredo; Pantano, Patrizia

    2017-06-01

    To assess functional rearrangement following neurodegeneration in the thalamus and dentate nucleus in patients with progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS). We recruited 19 patients with PSP, 11 with CBS and 14 healthy subjects. All the subjects underwent resting-state (rs) fMRI using a 3T system. Whole brain functional connectivity of the thalamus and dentate nucleus were calculated by means of a seed-based approach with FEAT script in FSL toolbox. Thalamic volume was calculated by means of FIRST, and the dentate area by means of Jim software. Both thalamic volume and dentate area were significantly smaller in PSP and CBS patients than in healthy subjects. No significant difference emerged in thalamic volume between PSP and CBS patients, whereas dentate area was significantly smaller in PSP than in CBS. Thalamic functional connectivity was significantly reduced in both patient groups in various cortical, subcortical and cerebellar areas. By contrast, changes in dentate nucleus functional connectivity differed in PSP and CBS: it decreased in subcortical and prefrontal cortical areas in PSP, but increased asymmetrically in the frontal cortex in CBS. Evaluating the dentate nucleus size and its functional connectivity may help to differentiate patients with PSP from those with CBS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Thalamic alexia with agraphia

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    Fábio Henrique de Gobbi Porto

    2012-02-01

    Full Text Available Alexia with agraphia is defined as an acquired impairment affecting reading and writing ability. It can be associated with aphasia, but can also occur as an isolated entity. This impairment has classically been associated with a left angular gyrus lesion In the present study, we describe a case involving a patient who developed alexia with agraphia and other cognitive deficits after a thalamic hemorrhage. In addition, we discuss potential mechanisms of this cortical dysfunction syndrome caused by subcortical injury. We examined a patient who presented with alexia with agraphia and other cognitive deficits due to a hemorrhage in the left thalamus. Neuropsychological evaluation showed attention, executive function, arithmetic and memory impairments. In addition, language tests revealed severe alexia with agraphia in the absence of aphasia. Imaging studies disclosed an old thalamic hemorrhage involving the anterior, dorsomedial and pulvinar nuclei. Tractography revealed asymmetric thalamocortical radiations in the parietal region (left - right, and single photon emission computed tomography demonstrated hypoperfusion in the left thalamus that extended to the frontal and parietal cortices. Cortical cognitive deficits, including alexia with agraphia, may occur as the result of thalamic lesions. The probable mechanism is a diaschisis phenomenon involving thalamic tract disconnections.

  15. Cannabis, Cigarettes, and Their Co-Occurring Use: Disentangling Differences in Gray Matter Volume

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    Jagannathan, Kanchana; Hager, Nathan; Childress, Anna Rose; Rao, Hengyi; Franklin, Teresa R.

    2015-01-01

    Background: Structural magnetic resonance imaging techniques are powerful tools for examining the effects of drug use on the brain. The nicotine and cannabis literature has demonstrated differences between nicotine cigarette smokers and cannabis users compared to controls in brain structure; however, less is known about the effects of co-occurring cannabis and tobacco use. Methods: We used voxel-based morphometry to examine gray matter volume differences between four groups: (1) cannabis-dependent individuals who do not smoke tobacco (Cs); (2) cannabis-dependent individuals who smoke tobacco (CTs); (3) cannabis-naïve, nicotine-dependent individuals who smoke tobacco (Ts); and (4) healthy controls (HCs). We also explored associations between gray matter volume and measures of cannabis and tobacco use. Results: A significant group effect was observed in the left putamen, thalamus, right precentral gyrus, and left cerebellum. Compared to HCs, the Cs, CTs, and Ts exhibited larger gray matter volumes in the left putamen. Cs also had larger gray matter volume than HCs in the right precentral gyrus. Cs and CTs exhibited smaller gray matter volume than HCs in the thalamus, and CTs and Ts had smaller left cerebellar gray matter volume than HCs. Conclusions: This study extends previous research that independently examined the effects of cannabis or tobacco use on brain structure by including an examination of co-occurring cannabis and tobacco use, and provides evidence that cannabis and tobacco exposure are associated with alterations in brain regions associated with addiction. PMID:26045474

  16. Abnormal Baseline Brain Activity in Drug-Naïve Patients with Tourette Syndrome: A Resting-state fMRI Study

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    Yonghua eCui

    2014-01-01

    Full Text Available Tourette Syndrome (TS is a childhood-onset chronic disorder characterized by the presence of multiple motor and vocal tics. This study investigated spontaneous low-frequency fluctuations in TS patients during resting-state functional magnetic resonance imaging (fMRI scans. We obtained resting-state fMRI scans from seventeen drug-naïve TS children and fifteen demographically matched healthy children. We computed the amplitude of low frequency fluctuation (ALFF and fractional ALFF (fALFF of resting-state fMRI data to measure spontaneous brain activity, and assessed the between-group differences in ALFF/fALFF and the relationship between ALFF/fALFF and tic severity scores. Our results showed that the children with TS exhibited significantly decreased ALFF in the posterior cingulate gyrus/precuneus and bilateral parietal gyrus. fALFF was decreased in TS children in the anterior cingulated cortex, bilateral middle and superior frontal cortices and superior parietal lobule, and increased in the left putamen and bilateral thalamus. Moreover, we found significantly positive correlations between fALFF and tic severity scores in the right thalamus. Our study provides empirical evidence for abnormal spontaneous neuronal activity in TS patients, which may implicate the underlying neurophysiological mechanism in TS and demonstrate the possibility of applying ALFF/fALFF for clinical TS studies.

  17. Thyroid hormones regulate levels of thyrotropin-releasing-hormone mRNA in the paraventricular nucleus

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    Koller, K.J.; Wolff, R.S.; Warden, M.K.; Zoeller, R.T.

    1987-10-01

    Cellular levels of messenger RNA encoding thyrotropin-releasing hormone (TRH) were measured in the paraventricular nucleus of the hypothalamus and the reticular nucleus of the thalamus in male rats after chemical thyroidectomy and thyroid hormone, replacement. TRH mRNA levels were measured by quantitative in situ hybridization histochemistry using a /sup 35/S-labeled synthetic 48-base oligodeoxynucleotide probe and quantitative autoradiography. Chemical thyroidectomy, produced by the administration of 6-(n-propyl)-2-thiouracil (PrSur), reduced plasma thyroxine below detection limits and significantly increased TRH mRNA in the paraventricular nucleus. Treatments with exogenous L-triiodothyronine (T/sub 3/) reduced TRH mRNA to the same level in both hypothyroid and euthyroid animals. Neither PrSur treatment nor T/sub 3/ replacement influenced TRH mRNA levels in the reticular nucleus of the thalamus. Blot hybridization analysis of electrophoretically fractionated total RNA from pituitaries of these animals indicated that thyrotropin-..beta.. mRNA levels were elevated after thyroidectomy and reduced by T/sub 3/ treatment, showing that the pituitary-thyroid axis was indeed stimulated by PrSur treatment. These results suggest that thyroid hormones are involved, either directly or indirectly, in regulating the biosynthesis of TRH in the thyrotropic center of the hypothalamus.

  18. Complex neurological symptoms in bilateral thalamic stroke due to Percheron artery occlusion

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    Caruso P

    2016-12-01

    Full Text Available Paola Caruso, Paolo Manganotti, Rita Moretti Department of Clinical Neurology, University of Trieste, Trieste, Italy Abstract: The artery of Percheron is a rare anatomical variant where a single thalamic perforating artery arises from the proximal posterior cerebral artery (P1 segment between the basilar artery and the posterior communicating artery and supplies the rostral mesencephalon and both paramedian territories of the thalami. Almost one-third of human brains present this variant. Occlusion of the artery of Percheron mostly results in a bilateral medial thalamic infarction, which usually manifests with altered consciousness (including coma, vertical gaze paresis, and cognitive disturbance. The presentation is similar to the “top of the basilar syndrome”, and early recognition should be prompted. We describe the case of a young female with this vessel variant who experienced a bilateral thalamic stroke. Magnetic resonance angiography demonstrated bilateral thalamic infarcts and a truncated artery of Percheron. Occlusion of the vessel was presumably due to embolism from a patent foramen ovale. Thrombolysis was performed, with incomplete symptom remission, cognitive impairment, and persistence of speech disorders. Early recognition and treatment of posterior circulation strokes is mandatory, and further investigation for underlying stroke etiologies is needed. Keywords: thalamus vascularization, cognitive impairment, paramedian thalamus territory, speech disorder, vertical gaze palsy

  19. Resting-state fMRI connectivity impairment in schizophrenia and bipolar disorder.

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    Argyelan, Miklos; Ikuta, Toshikazu; DeRosse, Pamela; Braga, Raphael J; Burdick, Katherine E; John, Majnu; Kingsley, Peter B; Malhotra, Anil K; Szeszko, Philip R

    2014-01-01

    Schizophrenia and bipolar disorder share aspects of phenomenology and neurobiology and thus may represent a continuum of disease. Few studies have compared connectivity across the brain in these disorders or investigated their functional correlates. We used resting-state functional magnetic resonance imaging to evaluate global and regional connectivity in 32 healthy controls, 19 patients with bipolar disorder, and 18 schizophrenia patients. Patients also received comprehensive neuropsychological and clinical assessments. We computed correlation matrices among 266 regions of interest within the brain, with the primary dependent measure being overall global connectivity strength of each region with every other region. Patients with schizophrenia had significantly lower global connectivity compared with healthy controls, whereas patients with bipolar disorder had global connectivity intermediate to and significantly different from those of patients with schizophrenia and healthy controls. Post hoc analyses revealed that compared with healthy controls, both patient groups had significantly lower connectivity in the paracingulate gyrus and right thalamus. Patients with schizophrenia also had significantly lower connectivity in the temporal occipital fusiform cortex, left caudate nucleus, and left thalamus compared with healthy controls. There were no significant differences among the patient groups in any of these regions. Lower global connectivity among all patients was associated with worse neuropsychological and clinical functioning, but these effects were not specific to any patient group. These findings are consistent with the hypothesis that schizophrenia and bipolar disorder may represent a continuum of global disconnectivity in the brain but that regional functional specificity may not be evident.

  20. Acute effects of the designer drugs benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP) using functional magnetic resonance imaging (fMRI) and the Stroop task--a pilot study.

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    Curley, Louise E; Kydd, Rob R; Robertson, Michelle C; Pillai, Avinesh; McNair, Nicolas; Lee, HeeSeung; Kirk, Ian J; Russell, Bruce R

    2015-08-01

    A novel group of designer drugs containing benzylpiperazine (BZP) and/or trifluoromethylphenylpiperazine (TFMPP) have been available worldwide for more than a decade; however, their effects on human brain function have not been extensively described. In a double-blind, placebo-controlled crossover study, the acute effects of BZP and TFMPP (alone and in combination) on the neural networks involved in executive function were investigated using an event-related Stroop functional magnetic resonance imaging (fMRI) paradigm. Thirteen healthy participants aged 18-40 years undertook the Stroop task 90 min after taking an oral dose of either BZP (200 mg), TFMPP (either 50 or 60 mg), BZP + TFMPP (100 + 30 mg) or placebo. A change in activity in neural regions reflects an increase in local demand for oxygen, due to an increase in neuronal activity. Relative to placebo, an increase in neural activation was observed in the dorsal striatum following BZP, and in the thalamus following TFMPP, when performing the Stroop task. These data suggest that additional compensatory resources were recruited to maintain performance during the Stroop task. When BZP and TFMPP were administered together, both the dorsal striatum and thalamus were activated. However, the combination of BZP/TFMPP attenuated activation in the caudate, possibly due to TFMPP's indirect effects on dopamine release via 5HT2C receptors.

  1. Regional homogeneity of intrinsic brain activity in happy and unhappy individuals.

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    Luo, Yangmei; Huang, Xiting; Yang, Zhen; Li, Baolin; Liu, Jie; Wei, Dongtao

    2014-01-01

    Why are some people happier than others? This question has intrigued many researchers. However, limited work has addressed this question within a neuroscientific framework. The present study investigated the neural correlates of trait happiness using the resting-state functional magnetic resonance imaging (rs-fMRI) approach. Specifically, regional homogeneity (ReHo) was examined on two groups of young adults: happy and unhappy individuals (N = 25 per group). Decreased ReHo in unhappy relative to happy individuals was observed within prefrontal cortex, medial temporal lobe, superior temporal lobe, and retrosplenial cortex. In contrast, increased ReHo in unhappy relative to happy individuals was observed within the dorsolateral prefrontal cortex, middle cingulate gyrus, putamen, and thalamus. In addition, the ReHo within the left thalamus was negatively correlated with Chinese Happiness Inventory (CHI) score within the happy group. As an exploratory study, we examined how general trait happiness is reflected in the regional homogeneity of intrinsic brain activity in a relatively small sample. Examining other types of happiness in a larger sample using a multitude of intrinsic brain activity indices are warranted for future work. The local synchronization of BOLD signal is altered in unhappy individuals. The regions implicated in this alteration partly overlapped with previously identified default mode network, emotional circuitry, and rewarding system, suggesting that these systems may be involved in happiness.

  2. Resting Brain Activity Related to Dispositional Mindfulness: a PET Study.

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    Gartenschläger, Martin; Schreckenberger, Mathias; Buchholz, Hans-Georg; Reiner, Iris; Beutel, Manfred E; Adler, Julia; Michal, Matthias

    2017-01-01

    Mindfulness denotes a state of consciousness characterized by receptive attention to and awareness of present events and experiences. As a personality trait, it constitutes the ability to become aware of mental activities such as sensations, images, feelings, and thoughts, and to disengage from judgment, conditioned emotions, and their cognitive processing or automatic inhibition. Default brain activity reflects the stream of consciousness and sense of self at rest. Analysis of brain activity at rest in persons with mindfulness propensity may help to elucidate the neurophysiological basis of this important mental trait. The sample consisted of 32 persons-23 with mental disorders and 9 healthy controls. Dispositional mindfulness (DM) was operationalized by Mindful Attention Awareness Scale (MAAS). Brain activity at rest with eyes closed was assessed by fluorodeoxyglucose positron emission tomography (F-18-FDG PET). After adjustment for depression, anxiety, age and years of education, resting glucose metabolism in superior parietal lobule and left precuneus/Brodmann area (BA) 7 was positively associated with DM. Activity of the left inferior frontal orbital gyrus (BA 47) and bilateral anterior thalamus were inversely associated with DM. DM appears to be associated with increased metabolic activity in some core area of the default mode network (DMN) and areas connected to the DMN, such as BA 7, hosting sense of self functions. Hypometabolism on the other hand was found in some nodes connected to the DMN, such as left inferior frontal orbital gyrus and bilateral thalamus, commonly related to functions of memory retrieval, decision making, or outward attention.

  3. Higher order thalamic nuclei resting network connectivity in early schizophrenia and major depressive disorder.

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    Penner, Jacob; Osuch, Elizabeth A; Schaefer, Betsy; Théberge, Jean; Neufeld, Richard W J; Menon, Ravi S; Rajakumar, Nagalingam; Bourne, James A; Williamson, Peter C

    2017-12-08

    The pulvinar and the mediodorsal (MDN) nuclei of the thalamus are higher order nuclei which have been implicated in directed effort and corollary discharge systems. We used seed-based resting fMRI to examine functional connectivity to bilateral pulvinar and MDN in 24 schizophrenic patients (SZ), 24 major depressive disorder patients (MDD), and 24 age-matched healthy controls. SZ had less connectivity than controls between the left pulvinar and precuneus, left ventral-lateral prefrontal cortex (vlPFC), and superior and medial-frontal regions, between the right pulvinar and right frontal pole, and greater connectivity between the right MDN and left dorsolateral prefrontal cortex (dlPFC). SZ had less connectivity than MDD between the left pulvinar and ventral anterior cingulate (vACC), left vlPFC, anterior insula, posterior cingulate cortex (PCC), and right hippocampus, between the right pulvinar and right PCC, and between the right MDN and right dorsal anterior cingulate (dACC). This is the first study to measure the functional connectivity to the higher order nuclei of the thalamus in both SZ and MDD. We observed less connectivity in SZ than MDD between pulvinar and emotional encoding regions, a directed effort region, and a region involved in representation and salience, and between MDN and a directed effort region. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Healthy brain ageing assessed with 18F-FDG PET and age-dependent recovery factors after partial volume effect correction

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    Bonte, Stijn [IBiTech, Ghent, (Belgium); Ghent University, iMinds - Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Ghent (Belgium); University Hospital, Department of Radiology and Nuclear Medicine, Ghent (Belgium); Vandemaele, Pieter; Deblaere, Karel; Goethals, Ingeborg [University Hospital, Department of Radiology and Nuclear Medicine, Ghent (Belgium); Verleden, Stijn; Audenaert, Kurt [University Hospital, Department of Psychiatry, Ghent (Belgium); Holen, Roel van [Ghent University, iMinds - Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Ghent (Belgium)

    2017-05-15

    The mechanisms of ageing of the healthy brain are not entirely clarified to date. In recent years several authors have tried to elucidate this topic by using {sup 18}F-FDG positron emission tomography. However, when correcting for partial volume effects (PVE), divergent results were reported. Therefore, it is necessary to evaluate these methods in the presence of atrophy due to ageing. In this paper we first evaluate the performance of two PVE correction techniques with a phantom study: the Rousset method and iterative deconvolution. We show that the ability of the latter method to recover the true activity in a small region decreases with increasing age due to brain atrophy. Next, we have calculated age-dependent recovery factors to correct for this incomplete recovery. These factors were applied to PVE-corrected {sup 18}F-FDG PET scans of healthy subjects for mapping the agedependent metabolism in the brain. Many regions in the brain show a reduced metabolism with ageing, especially in grey matter in the frontal and temporal lobe. An increased metabolism is found in grey matter of the cerebellum and thalamus. Our study resulted in age-dependent recovery factors which can be applied following standard PVE correction methods. Cancelling the effect of atrophy, we found regional changes in {sup 18}F-FDG metabolism with ageing. A decreasing trend is found in the frontal and temporal lobe, whereas an increasing metabolism with ageing is observed in the thalamus and cerebellum.

  5. Functional neuroimaging in specific phobia.

    Science.gov (United States)

    Del Casale, Antonio; Ferracuti, Stefano; Rapinesi, Chiara; Serata, Daniele; Piccirilli, Massimo; Savoja, Valeria; Kotzalidis, Georgios D; Manfredi, Giovanni; Angeletti, Gloria; Tatarelli, Roberto; Girardi, Paolo

    2012-06-30

    Specific phobias (SPs) are common, with lifetime prevalence estimates of 10%. Our current understanding of their pathophysiology owes much to neuroimaging studies, which enabled us to construct increasingly efficient models of the underlying neurocircuitry. We provide an updated, comprehensive review and analyze the relevant literature of functional neuroimaging studies in specific phobias. Findings are presented according to the functional neuroanatomy of patients with SPs. We performed a careful search of the major medical and psychological databases by crossing SP with each neuroimaging technique. Functional neuroimaging, mostly using symptom provocation paradigms, showed abnormal activations in brain areas involved in emotional perception and early amplification, mainly the amygdala, anterior cingulate cortex, thalamus, and insula. The insula, thalamus and other limbic/paralimbic structures are particularly involved in SPs with prominent autonomic arousal. Emotional modulation is also impaired after exposure to phobic stimuli, with abnormal activations reported for the prefrontal, orbitofrontal and visual cortices. Other cortices and the cerebellum also appear to be involved in the pathophysiology of this disorder. Functional neuroimaging identified neural substrates that differentiate SPs from other anxiety disorders and separate SP subtypes from one another; the results support current Diagnostic and Statistical Manual of Mental Disorders, 4th edition-Text Revision (DSM-IV-TR) diagnostic subtyping of SPs. Functional neuroimaging shows promise as a means of identifying treatment-response predictors. Improvement in these techniques may help in clarifying the neurocircuitry underlying SP, for both research and clinical-therapeutic purposes. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Neuronal nonlinearity explains greater visual spatial resolution for darks than lights.

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    Kremkow, Jens; Jin, Jianzhong; Komban, Stanley J; Wang, Yushi; Lashgari, Reza; Li, Xiaobing; Jansen, Michael; Zaidi, Qasim; Alonso, Jose-Manuel

    2014-02-25

    Astronomers and physicists noticed centuries ago that visual spatial resolution is higher for dark than light stimuli, but the neuronal mechanisms for this perceptual asymmetry remain unknown. Here we demonstrate that the asymmetry is caused by a neuronal nonlinearity in the early visual pathway. We show that neurons driven by darks (OFF neurons) increase their responses roughly linearly with luminance decrements, independent of the background luminance. However, neurons driven by lights (ON neurons) saturate their responses with small increases in luminance and need bright backgrounds to approach the linearity of OFF neurons. We show that, as a consequence of this difference in linearity, receptive fields are larger in ON than OFF thalamic neurons, and cortical neurons are more strongly driven by darks than lights at low spatial frequencies. This ON/OFF asymmetry in linearity could be demonstrated in the visual cortex of cats, monkeys, and humans and in the cat visual thalamus. Furthermore, in the cat visual thalamus, we show that the neuronal nonlinearity is present at the ON receptive field center of ON-center neurons and ON receptive field surround of OFF-center neurons, suggesting an origin at the level of the photoreceptor. These results demonstrate a fundamental difference in visual processing between ON and OFF channels and reveal a competitive advantage for OFF neurons over ON neurons at low spatial frequencies, which could be important during cortical development when retinal images are blurred by immature optics in infant eyes.

  7. T1 Shortening in the Globus Pallidus after Multiple Administrations of Gadobutrol: Assessment with a Multidynamic Multiecho Sequence.

    Science.gov (United States)

    Kang, Koung Mi; Choi, Seung Hong; Hwang, Moonjung; Yun, Tae Jin; Kim, Ji-Hoon; Sohn, Chul-Ho

    2017-11-01

    Purpose To determine the association between the administration of the macrocyclic contrast medium gadobutrol and T1 relaxation time in the brains of patients with normal renal function by using multidynamic multiecho (MDME) magnetic resonance (MR) imaging sequences. Materials and Methods The institutional review board approved this retrospective study, and the need to obtain written informed consent was waived. This study included 46 patients (revealed by an electronic medical record search) who had received one or more gadobutrol injections and a maximum of one MR imaging contrast medium injection other than gadobutrol before MDME sequence acquisition. One radiologist performed quantitative analyses of regions of interest on quantitative T1 maps twice to cover the normal-appearing globus pallidus (GP), frontal white matter, frontal cortex, and thalamus. The number of administrations and the cumulative dose of gadobutrol, age, intervals between administrations, sex, and treatment were investigated. Univariable and multivariable linear regression analyses of the T1 values in four brain regions and the GP-to-thalamus signal intensity (SI) ratio were performed. P values of less than the Bonferroni-corrected value of .01 were considered to indicate significant differences. Results Intraobserver reproducibility was good to excellent (intraclass correlation coefficients, 0.62-0.81). Because of high multicollinearity between the number of gadobutrol administrations and accumulated dose (r = 0.96, P .01). Conclusion Multiple exposures to gadobutrol are associated with T1 shortening in the GP. (©) RSNA, 2017 Online supplemental material is available for this article.

  8. Humans use internal models to construct and update a sense of verticality.

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    Barra, Julien; Marquer, Adélaïde; Joassin, Roxane; Reymond, Céline; Metge, Liliane; Chauvineau, Valérie; Pérennou, Dominic

    2010-12-01

    Internal models serve sensory processing, sensorimotor integration and motor control. They could be a way to construct and update a sense of verticality, by combining vestibular and somatosensory graviception. We tested this hypothesis by investigating self-orientation relative to gravity in 39 normal subjects and in subjects with various somatosensory losses showing either a complete deafferentation of trunk and lower limbs (14 paraplegic patients after complete traumatic spinal cord injury) or a gradient in the degree of a hemibody sensory loss (23 hemiplegic patients after stroke). We asked subjects to estimate, in the dark, the direction of the Earth vertical in two postural conditions-upright and at lateral whole body tilt. For upright conditions, verticality estimates were not different from the direction of the Earth vertical in normal (0.24° ± 1; P = 0.42) and paraplegic subjects (0.87° ± 0.9; P = 0.14). The within-subject variability was much greater in hemiplegic than in normal subjects (2.05° ± 1.15 versus 1.06° ± 0.4; P integrity of the posterolateral thalamus. This study reveals the existence of a synthesis of vestibular and somaesthetic graviception for which the posterolateral thalamus plays a major role. This corresponds to a primary property of internal models and yields the neural bases of the Aubert effect. We conclude that humans construct and update internal models of verticality in which somatosensory information plays an important role.

  9. Efficacy of T2*-Weighted Gradient-Echo MRI in Early Diagnosis of Cerebral Venous Thrombosis with Unilateral Thalamic Lesion

    Directory of Open Access Journals (Sweden)

    Shingo Mitaki

    2013-01-01

    Full Text Available Cerebral venous thrombosis (CVT is an uncommon cause of stroke with diverse etiologies and varied clinical presentations. Because of variability in clinical presentation and neuroimaging, CVT remains a diagnostic challenge. Recently, some studies have highlighted the value of T2*-weighted gradient-echo MRI (T2*WI in the diagnosis of CVT. We report the case of a 79-year-old woman with CVT due to a hypercoagulable state associated with cancer. On the initial T2-weighted image (T2WI, there was a diffuse high-intensity lesion in the right thalamus, extending into the posterior limb of the internal capsule and midbrain. T2*WI showed diminished signal and enlargement of the right basilar vein and the vein of Galen. Even though there is a wide range of differential diagnoses in unilateral thalamic lesions, and a single thalamus lesion is a rare entity of CVT, based on T2*WI findings we could make an early diagnosis and perform treatment. Our case report suggests that T2*WI could detect thrombosed veins and be a useful method of early diagnosis in CVT.

  10. Abnormal functioning of the thalamocortical system underlies the conscious awareness of the phantom limb phenomenon.

    Science.gov (United States)

    Romero-Romo, J I; Bauer, C C C; Pasaye, E H; Gutiérrez, R A; Favila, R; Barrios, F A

    2010-12-01

    Phantom limb (PL), a phenomenon experienced by most patients after amputation, has mostly served as a paradigm to study experiences that appear to be associated with neural plasticity within the CNS. However, the subjective nature of PL experiences has had no definitive means of reliable assessment other than using patients' direct reports, nor was there a way to study the neural mechanisms involved in the conscious awareness of this mental phenomenon. Here we obtained patients' indirect responses to PL experiences for an objective evaluation using functional magnetic resonance imaging (fMRI). Six control subjects and six lower limb (LL) amputees participated in a motor imagery task for both the intact and the particular phantom toes. While all subjects shared neural processing of distinctive regional cerebral activations during motor imagery of the intact toes (prefrontal (PF), supplementary motor area (SMA), primary motor cortex (M1), superior temporal gyrus (STG)), it was only during motor imagery of the amputated toes in amputees that we observed an increased blood oxygen level-dependent (BOLD) signal in the contralateral basal ganglia at the medial globus pallidus (MGP), substantia nigra (SN), and thalamus. This increased BOLD signal in the basal ganglia-thalamus-cortex pathway during imaginary movement of the phantom toes may reflect an abnormal open loop functioning of the thalamocortical system underlying the conscious awareness of the phantom phenomenon. We suggest that the reduction in afferent information contributes to and coalesces with the higher-level reorganization resulting in the subjective conscious awareness of the phantom limb.

  11. Motor cortex neuroplasticity following brachial plexus transfer.

    Science.gov (United States)

    Dimou, Stefan; Biggs, Michael; Tonkin, Michael; Hickie, Ian B; Lagopoulos, Jim

    2013-01-01

    In the past decade, research has demonstrated that cortical plasticity, once thought only to exist in the early stages of life, does indeed continue on into adulthood. Brain plasticity is now acknowledged as a core principle of brain function and describes the ability of the central nervous system to adapt and modify its structural organization and function as an adaptive response to functional demand. In this clinical case study we describe how we used neuroimaging techniques to observe the functional topographical expansion of a patch of cortex along the sensorimotor cortex of a 27-year-old woman following brachial plexus transfer surgery to re-innervate her left arm. We found bilateral activations present in the thalamus, caudate, insula as well as across the sensorimotor cortex during an elbow flex motor task. In contrast we found less activity in the sensorimotor cortex for a finger tap motor task in addition to activations lateralized to the left inferior frontal gyrus and thalamus and bilaterally for the insula. From a pain perspective the patient who had experienced extensive phantom limb pain (PLP) before surgery found these sensations were markedly reduced following transfer of the right brachial plexus to the intact left arm. Within the context of this clinical case the results suggest that functional improvements in limb mobility are associated with increased activation in the sensorimotor cortex as well as reduced PLP.

  12. Thalamo-cortical interactions modeled by weakly connected oscillators: could the brain use FM radio principles?

    Science.gov (United States)

    Hoppensteadt, F C; Izhikevich, E M

    1998-01-01

    We consider all models of the thalamo-cortical system that satisfy the following two assumptions: (1) each cortical column is an autonomous oscillator; (2) connections between cortical columns and the thalamus are weak. Our goal is to deduce from these assumptions general principles of thalamo-cortical interactions that are independent of the equations describing the system. We find that the existence of synaptic connections between any two cortical columns does not guarantee that the columns interact: They interact only when there is a certain nearly resonant relation between their frequencies, which implies that the interactions are frequency modulated (FM). When the resonance relation holds, the cortical columns interact through phase modulations. Thus, communications between weakly connected cortical oscillators employ a principle similar to that in FM radio: The frequency of oscillation encodes the channel of communication, while the information is transmitted via phase modulations. If the thalamic input has an appropriate frequency, then it can dynamically link any two cortical columns, even those that have non-resonant frequencies and would otherwise be unlinked. Thus, by adjusting its temporal activity, the thalamus has control over information processing taking place in the cortex. Our results suggest that the mean firing rate (frequency) of periodically spiking neuron does not carry any information other than identifying a channel of communication. Information (i.e. neural code) is carried through modulations of interspike intervals.

  13. Increasing signal intensity within the dentate nucleus and globus pallidus on unenhanced T1W magnetic resonance images in patients with relapsing-remitting multiple sclerosis: correlation with cumulative dose of a macrocyclic gadolinium-based contrast agent, gadobutrol

    Energy Technology Data Exchange (ETDEWEB)

    Stojanov, Dragan A. [University of Nis, Faculty of Medicine, Nis (Serbia); Clinical Center Nis, Center for Radiology, Nis (Serbia); Aracki-Trenkic, Aleksandra [Clinical Center Nis, Center for Radiology, Nis (Serbia); Vojinovic, Slobodan; Ljubisavljevic, Srdjan [University of Nis, Faculty of Medicine, Nis (Serbia); Clinical Center Nis, Clinic for Neurology, Nis (Serbia); Benedeto-Stojanov, Daniela [University of Nis, Faculty of Medicine, Nis (Serbia)

    2016-03-15

    To evaluate correlation between cumulative dose of gadobutrol and signal intensity (SI) within dentate nucleus and globus pallidus on unenhanced T1-weighted images in patients with relapsing-remitting multiple sclerosis (RRMS). Dentate nucleus-to-pons and globus pallidus-to-thalamus SI ratios, and renal and liver functions, were evaluated after multiple intravenous administrations of 0.1 mmol/kg gadobutrol at 27, 96-98, and 168 weeks. We compared SI ratios based on the number of administrations, total amount of gadobutrol administered, and time between injections. Globus pallidus-to-thalamus (p = 0.025) and dentate nucleus-to-pons (p < 0.001) SI ratios increased after multiple gadobutrol administrations, correlated with the number of administrations (ρ = 0.263, p = 0.046, respectively) and depended on the length of administration (p = 0.017, p = 0.037, respectively). Patients receiving gadobutrol at 27 weeks showed the greatest increase in both SI ratios (p = 0.006; p = 0.014, respectively, versus 96-98 weeks). GGT increased at the end of the study (p = 0.004). In patients with RRMS, SI within the dentate nucleus and globus pallidus increased on unenhanced T1-weighted images after multiple gadobutrol injections. Administration of the same total amount of gadobutrol over a shorter period caused greater SI increase. (orig.)

  14. Aberrant functional connectivity in Papez circuit correlates with memory performance in cognitively intact middle-aged APOE4 carriers.

    Science.gov (United States)

    Li, Wenjun; Antuono, Piero G; Xie, Chunming; Chen, Gang; Jones, Jennifer L; Ward, B Douglas; Singh, Suraj P; Franczak, Malgorzata B; Goveas, Joseph S; Li, Shi-Jiang

    2014-08-01

    The main objective of this study is to detect the early changes in resting-state Papez circuit functional connectivity using the hippocampus as the seed, and to determine the associations between altered functional connectivity (FC) and the episodic memory performance in cognitively intact middle-aged apolipoprotein E4 (APOE4) carriers who are at risk of Alzheimer's disease (AD). Forty-six cognitively intact, middle-aged participants, including 20 APOE4 carriers and 26 age-, sex-, and education-matched noncarriers were studied. The resting-state FC of the hippocampus (HFC) was compared between APOE4 carriers and noncarriers. APOE4 carriers showed significantly decreased FC in brain areas that involve learning and memory functions, including the frontal, cingulate, thalamus and basal ganglia regions. Multiple linear regression analysis showed significant correlations between HFC and the episodic memory performance. Conjunction analysis between neural correlates of memory and altered HFC showed the overlapping regions, especially the subcortical regions such as thalamus, caudate nucleus, and cingulate cortices involved in the Papez circuit. Thus, changes in connectivity in the Papez circuit may be used as an early risk detection for AD. Copyright © 2014. Published by Elsevier Ltd.

  15. Independent component analysis (ICA) of generalized spike wave discharges in fMRI: comparison with general linear model-based EEG-fMRI.

    Science.gov (United States)

    Moeller, Friederike; LeVan, Pierre; Gotman, Jean

    2011-02-01

    Most EEG-fMRI studies in epileptic patients are analyzed using the general linear model (GLM), which assumes a known hemodynamic response function (HRF) to epileptic spikes. In contrast, independent component analysis (ICA) can extract blood-oxygenation level dependent (BOLD) responses without imposing constraints on the HRF. ICA might therefore detect responses that vary in time and shape, and that are not detected in the GLM analysis. In this study, we compared the findings of ICA and GLM analyses in 12 patients with idiopathic generalized epilepsy. Spatial ICA was used to extract independent components from the functional magnetic resonance imaging (fMRI) data. A deconvolution method identified component time courses significantly related to the generalized EEG discharges, without constraining the shape of the HRF. The results from the ICA analysis were compared to those from the GLM analysis. GLM maps and ICA maps showed significant correlation and revealed BOLD responses in the thalamus, caudate nucleus, and default mode areas. In patients with a low rate of discharges per minute, the GLM analysis detected BOLD signal changes within the thalamus and the caudate nucleus that were not revealed by the ICA. In conclusion, ICA is a viable alternative technique to GLM analyses in EEG-fMRI studies related to generalized discharges. This study demonstrated that the BOLD response largely resembles the standard HRF and that GLM analysis is adequate. However, ICA is more dependent on a sufficient number of events than GLM analysis. Copyright © 2010 Wiley-Liss, Inc.

  16. Differential Activation Patterns of fMRI in Sleep-Deprived Brain: Restoring Effects of Acupuncture

    Directory of Open Access Journals (Sweden)

    Lei Gao

    2014-01-01

    Full Text Available Previous studies suggested a remediation role of acupuncture in insomnia, and acupuncture also has been used in insomnia empirically and clinically. In this study, we employed fMRI to test the role of acupuncture in sleep deprivation (SD. Sixteen healthy volunteers (8 males were recruited and scheduled for three fMRI scanning procedures, one following the individual’s normal sleep and received acupuncture SP6 (NOR group and the other two after 24 h of total SD with acupuncture on SP6 (SD group or sham (Sham group. The sessions were counterbalanced approximately two weeks apart. Acupuncture stimuli elicited significantly different activation patterns of three groups. In NOR group, the right superior temporal lobe, left inferior parietal lobule, and left postcentral gyrus were activated; in SD group, the anterior cingulate cortex, bilateral insula, left basal ganglia, and thalamus were significantly activated while, in Sham group, the bilateral thalamus and left cerebellum were activated. Different activation patterns suggest a unique role of acupuncture on SP6 in remediation of SD. SP6 elicits greater and anatomically different activations than those of sham stimuli; that is, the salience network, a unique interoceptive autonomic circuit, may indicate the mechanism underlying acupuncture in restoring sleep deprivation.

  17. Neural substrates of irony comprehension: A functional MRI study.

    Science.gov (United States)

    Shibata, Midori; Toyomura, Akira; Itoh, Hiroaki; Abe, Jun-ichi

    2010-01-13

    In daily communication, we sometimes use ironic expressions to convey the opposite meaning. To understand these contradictory statements, we have to infer contextual implications and the speaker's mental state. However, little is known about how our brains carry out these complex processes. In this study, we investigated the neural substrates involved in irony comprehension using echoic utterance (Sperber and Wilson, 1986, 1995). Participants read a short scenario that consisted of five sentences. The first four sentences explained the situation of the protagonists. The fifth connoted either an ironic, literal, or unconnected meaning. The participants had to press a button to indicate whether or not the final sentence expressed irony. In the ironic sentence condition, the bilateral superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus, medial prefrontal cortex, superior temporal gyrus, inferior parietal lobule, caudate, thalamus, the left insula, and amygdala were activated. In the literal sentence condition, the right superior frontal gyrus, the bilateral middle frontal gyrus, inferior frontal gyrus, medial prefrontal cortex, superior temporal gyrus, inferior parietal lobule, caudate, the left insula, the right thalamus, and the left amygdala were activated. However, in the ironic sentence condition minus the literal sentence condition, we observed higher activation in the right medial prefrontal cortex (BA 10), the right precentral (BA 6), and the left superior temporal sulcus (BA 21). Our results suggest that irony comprehension is strongly related to mentalizing processes and that activation in these regions might be affected by higher-order cognitive operations.

  18. Cognitive impairment related changes in the elemental concentration in the brain of old rat

    Energy Technology Data Exchange (ETDEWEB)

    Serpa, R.F.B. [Federal University of Rio de Janeiro/COPPE, Nuclear Instrumentation Laboratory, P.O. Box: 68509, Zip Code: 21941-972, Rio de Janeiro (Brazil)]. E-mail: renata@lin.ufrj.br; Jesus, E.F.O. de [University of Rio de Janeiro State, Physics Institute, RJ (Brazil); Anjos, M.J. [Federal University of Rio de Janeiro/COPPE, Nuclear Instrumentation Laboratory, P.O. Box: 68509, Zip Code: 21941-972, Rio de Janeiro (Brazil); University of Rio de Janeiro State, Physics Institute, RJ (Brazil); Lopes, R.T. [Federal University of Rio de Janeiro/COPPE, Nuclear Instrumentation Laboratory, P.O. Box: 68509, Zip Code: 21941-972, Rio de Janeiro (Brazil); Carmo, M.G.T. do [Federal University of Rio de Janeiro, Nutrition Institute, RJ (Brazil); Rocha, M.S. [Federal University of Rio de Janeiro, Department of Basics and Clinic Pharmacy, RJ (Brazil); Rodrigues, L.C. [Federal University of Rio de Janeiro, Department of Basics and Clinic Pharmacy, RJ (Brazil); Moreira, S. [University of Campinas State, Civil Engineering Department, SP (Brazil); Martinez, A.M.B. [Federal University of Rio de Janeiro, Department of Histology and Embryology, RJ (Brazil)

    2006-11-15

    In order to evaluate the elemental concentration as a function of learning and memory deficiency, six different structures of the brain were analyzed by total reflection X-ray fluorescence spectrometry with synchrotron radiation (SR-TXRF). To evaluate the cognitive processes, the animals were tested in an adaptation of the Morris water maze. After the test, the animals were divided into two groups: cognitively healthy (control group) and cognitively impaired. The measurements were carried out at XRF beam line at Light Synchrotron Brazilian laboratory, Campinas, Brazil. The following elements were identified: Al, P, S, Cl, K, Ca, Ti, Cr, Fe, Cu, Zn, Br and Rb. K concentration was higher in all regions of the brain studied for control group than the cognitively impaired group. Moreover, the control group presented higher levels for P and Fe in the entorhinal cortex, in the temporal cortex (only P), in the hypothalamus and in the thalamus, than the cognitively impaired group. Br concentration in the animals which presented cognitive impairment was three times larger in the hypothalamus and thalamus, twice larger in temporal cortex and higher in visual cortex than the cognitively healthy group. Cu was more remarkable in the hippocampus and hypothalamus from the animals with cognitive impairment than the control group. We observed that the cognitively impaired group presented highest concentrations of Br and Cu in certain areas than the control group, on the other hand, this group presented highest levels of K for all brain areas studied.

  19. Reduced thalamic and pontine connectivity in Kleine-Levin syndrome

    Directory of Open Access Journals (Sweden)

    Maria eEngström

    2014-04-01

    Full Text Available The Kleine-Levin syndrome is a rare sleep disorder, characterized by exceptionally long sleep episodes. The neuropathology of the syndrome is unknown and treatment is often inadequate. The aim of the study was to improve understanding of the underlying neuropathology, related to cerebral networks, in Kleine-Levin syndrome during sleep episodes. One patient with Kleine-Levin syndrome and congenital nystagmus, was investigated by resting state functional Magnetic Resonance Imaging during both asymptomatic and hypersomnic periods. Fourteen healthy subjects were also investigated as control samples. Functional connectivity was assessed from seed regions of interest in the thalamus and the dorsal pons. Thalamic connectivity was normal in the asymptomatic patient whereas the connectivity between the brain stem, including dorsal pons, and the thalamus was diminished during hypersomnia. These results suggest that the patient’s nystagmus and hypersomnia might have their pathological origin in adjacent dorsal pontine regions. This finding provides additional knowledge of the cerebral networks involved in the neuropathology of this disabling disorder. Furthermore, these findings regarding a rare syndrome have broad implications and results could be of interest to researchers and clinicians in the whole field of sleep medicine.

  20. Sleep onset uncovers thalamic abnormalities in patients with idiopathic generalised epilepsy

    Directory of Open Access Journals (Sweden)

    Andrew P. Bagshaw

    2017-01-01

    Full Text Available The thalamus is crucial for sleep regulation and the pathophysiology of idiopathic generalised epilepsy (IGE, and may serve as the underlying basis for the links between the two. We investigated this using EEG-fMRI and a specific emphasis on the role and functional connectivity (FC of the thalamus. We defined three types of thalamic FC: thalamocortical, inter-hemispheric thalamic, and intra-hemispheric thalamic. Patients and controls differed in all three measures, and during wakefulness and sleep, indicating disorder-dependent and state-dependent modification of thalamic FC. Inter-hemispheric thalamic FC differed between patients and controls in somatosensory regions during wakefulness, and occipital regions during sleep. Intra-hemispheric thalamic FC was significantly higher in patients than controls following sleep onset, and disorder-dependent alterations to FC were seen in several thalamic regions always involving somatomotor and occipital regions. As interactions between thalamic sub-regions are indirect and mediated by the inhibitory thalamic reticular nucleus (TRN, the results suggest abnormal TRN function in patients with IGE, with a regional distribution which could suggest a link with the thalamocortical networks involved in the generation of alpha rhythms. Intra-thalamic FC could be a more widely applicable marker beyond patients with IGE.