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  1. Thinking outside a less intact box: thalamic dopamine D2 receptor densities are negatively related to psychometric creativity in healthy individuals.

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    Orjan de Manzano

    Full Text Available Several lines of evidence support that dopaminergic neurotransmission plays a role in creative thought and behavior. Here, we investigated the relationship between creative ability and dopamine D2 receptor expression in healthy individuals, with a focus on regions where aberrations in dopaminergic function have previously been associated with psychotic symptoms and a genetic liability to schizophrenia. Scores on divergent thinking tests (Inventiveness battery, Berliner Intelligenz Struktur Test were correlated with regional D2 receptor densities, as measured by Positron Emission Tomography, and the radioligands [(11C]raclopride and [(11C]FLB 457. The results show a negative correlation between divergent thinking scores and D2 density in the thalamus, also when controlling for age and general cognitive ability. Hence, the results demonstrate that the D2 receptor system, and specifically thalamic function, is important for creative performance, and may be one crucial link between creativity and psychopathology. We suggest that decreased D2 receptor densities in the thalamus lower thalamic gating thresholds, thus increasing thalamocortical information flow. In healthy individuals, who do not suffer from the detrimental effects of psychiatric disease, this may increase performance on divergent thinking tests. In combination with the cognitive functions of higher order cortical networks, this could constitute a basis for the generative and selective processes that underlie real life creativity.

  2. Thinking Outside a Less Intact Box: Thalamic Dopamine D2 Receptor Densities Are Negatively Related to Psychometric Creativity in Healthy Individuals

    OpenAIRE

    de Manzano, Örjan; Cervenka, Simon; Karabanov, Anke; Farde, Lars; Ullén, Fredrik

    2010-01-01

    Several lines of evidence support that dopaminergic neurotransmission plays a role in creative thought and behavior. Here, we investigated the relationship between creative ability and dopamine D2 receptor expression in healthy individuals, with a focus on regions where aberrations in dopaminergic function have previously been associated with psychotic symptoms and a genetic liability to schizophrenia. Scores on divergent thinking tests (Inventiveness battery, Berliner Intelligenz Struktur Te...

  3. Orexin Signaling in the Paraventricular Thalamic Nucleus Modulates Mesolimbic Dopamine and Hedonic Feeding in the Rat

    OpenAIRE

    Choi, Derrick L.; Davis, Jon F.; Magrisso, Irwin J.; Fitzgerald, Maureen E.; Lipton, Jack W.; Benoit, Stephen C.

    2012-01-01

    Data from our lab indicate that the orexin system is involved in the regulation of both conditioned and unconditioned responding for palatable foods. Anticipation of food rewards activates orexin receptor containing neurons within the paraventricular nucleus of the thalamus (PVT). The PVT regulates mesolimbic dopamine neurochemistry through direct connections with the nucleus accumbens and modulates the processing of cognitive-emotional information, suggesting that the PVT may represent a uni...

  4. Striatal dopamine D2 receptor availability predicts the thalamic and medial prefrontal responses to reward in cocaine abusers three years later

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    Asensio, S.; Goldstein, R.; Asensio, S.; Romero, M.J.; Romero, F.J.; Wong, C.T.; Alia-Klein, N.; Tomasi, D.; Wang, G.-J.; Telang, F..; Volkow, N.D.; Goldstein, R.Z.

    2010-05-01

    Low levels of dopamine (DA) D2 receptor availability at a resting baseline have been previously reported in drug addicted individuals and have been associated with reduced ventral and dorsal prefrontal metabolism. The reduction in DA D2 receptor availability along with the reduced ventral frontal metabolism is thought to underlie compromised sensitivity to nondrug reward, a core characteristic of drug addiction. We therefore hypothesized that variability in DA D2 receptor availability at baseline will covary with dynamic responses to monetary reward in addicted individuals. Striatal DA D2 receptor availability was measured with [{sup 11}C]raclopride and positron emission tomography and response to monetary reward was measured (an average of three years later) with functional magnetic resonance imaging in seven cocaine-addicted individuals. Results show that low DA D2 receptor availability in the dorsal striatum was associated with decreased thalamic response to monetary reward; while low availability in ventral striatum was associated with increased medial prefrontal (Brodmann Area 6/8/32) response to monetary reward. These preliminary results, that need to be replicated in larger sample sizes and validated with healthy controls, suggest that resting striatal DA D2 receptor availability predicts variability in functional responses to a nondrug reinforcer (money) in prefrontal cortex, implicated in behavioral monitoring, and in thalamus, implicated in conditioned responses and expectation, in cocaine-addicted individuals.

  5. Striatal dopamine D2 receptor availability predicts the thalamic and medial prefrontal responses to reward in cocaine abusers three years later

    International Nuclear Information System (INIS)

    Low levels of dopamine (DA) D2 receptor availability at a resting baseline have been previously reported in drug addicted individuals and have been associated with reduced ventral and dorsal prefrontal metabolism. The reduction in DA D2 receptor availability along with the reduced ventral frontal metabolism is thought to underlie compromised sensitivity to nondrug reward, a core characteristic of drug addiction. We therefore hypothesized that variability in DA D2 receptor availability at baseline will covary with dynamic responses to monetary reward in addicted individuals. Striatal DA D2 receptor availability was measured with (11C)raclopride and positron emission tomography and response to monetary reward was measured (an average of three years later) with functional magnetic resonance imaging in seven cocaine-addicted individuals. Results show that low DA D2 receptor availability in the dorsal striatum was associated with decreased thalamic response to monetary reward; while low availability in ventral striatum was associated with increased medial prefrontal (Brodmann Area 6/8/32) response to monetary reward. These preliminary results, that need to be replicated in larger sample sizes and validated with healthy controls, suggest that resting striatal DA D2 receptor availability predicts variability in functional responses to a nondrug reinforcer (money) in prefrontal cortex, implicated in behavioral monitoring, and in thalamus, implicated in conditioned responses and expectation, in cocaine-addicted individuals.

  6. Thalamic infarcts and hemorrhages.

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    Amici, Serena

    2012-01-01

    The anatomy and supply of thalamic arteries are briefly described here. Thalamic infarcts and small-size hemorrhages are classified according to their sites: (1) posterolateral, (2) anterolateral, (3) medial, and (4) dorsal. (1) Posterolateral hemorrhages or lateral thalamic infarcts are usually characterized by severe motor impairment and sensory loss. Transient reduced consciousness, vertical-gaze abnormalities, and small fixed pupils may be evidenced. (2) Patients with anterolateral hemorrhages or tuberothalamic artery infarcts present frontal-type neuropsychological symptoms associated with mild hemiparesis and hemihypesthesia. (3) Medially located hemorrhages or paramedian artery infarcts have decreased levels of consciousness, vertical- and horizontal-gaze abnormalities, amnesia, and abulia. (4) Dorsal hemorrhages or posterior choroidal artery infarcts present with minimal transient hemiparesis and hemihypesthesia; apraxia, aphasia, and amnesia have also been described. PMID:22377880

  7. 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.

  8. Genetics Home Reference: dopamine beta-hydroxylase deficiency

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    ... Genetics Home Health Conditions dopamine beta-hydroxylase deficiency dopamine beta-hydroxylase deficiency Enable Javascript to view the ... boxes. Print All Open All Close All Description Dopamine beta (β)-hydroxylase deficiency is a condition that ...

  9. Altered thalamic functional connectivity in multiple sclerosis

    International Nuclear Information System (INIS)

    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

  10. Altered thalamic functional connectivity in multiple sclerosis

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    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

  11. Symmetrical thalamic lesions in infants.

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    Eicke, M.; Briner, J; Willi, U; Uehlinger, J; Boltshauser, E

    1992-01-01

    Clinical observations and findings on imaging are reported in six newborns with symmetrical thalamic lesions (STL). In three cases the diagnosis was confirmed by postmortem examination. Characteristic observations in this series and 17 previously reported cases include no evidence of perinatal asphyxia, high incidence of polyhydramnios, absent suck and swallow, absent primitive reflexes, appreciable spasticity at or within days of birth, lack of psychomotor development, and death within days ...

  12. Permanent tremor reduction during thalamic stimulation in Multiple Sclerosis

    OpenAIRE

    Thevathasan, Wesley; Schweder, Patrick; Joint, Carole; Ray, Nicola; Pretorius, Pieter; Gregory, Ralph; Aziz, Tipu

    2010-01-01

    Abstract Background: Unlike thalamic lesioning, thalamic stimulation is considered a reversible treatment for tremor. However, tremor in Multiple Sclerosis (MS) can sometimes permanently improve during thalamic stimulation. Such 'permanent tremor reduction' (PTR) has been attributed to limb weakness preventing tremor expression. In this study, eleven consecutive patients with MS tremor treated with thalamic stimulation were assessed for PTR. Eighteen upper limbs had tremor, of ...

  13. Preoperative shunts in thalamic tumours.

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    Goel A

    2000-10-01

    Full Text Available Thirty one patients with thalamic glioma underwent a pre-tumour resection shunt surgery. The procedure was uneventful in 23 patients with relief from symptoms of increased intracranial pressure. Eight patients worsened after the procedure. The level of sensorium worsened from excessively drowsy state to unconsciousness in seven patients. Three patients developed hemiparesis, 4 developed paresis of extra-ocular muscles and altered pupillary reflexes, and 1 developed incontinence of urine and persistent vomiting. Alteration in the delicately balanced intracranial pressure and movements in the tumour and vital adjacent brain areas could be the probable cause of the worsening in the neurological state in these 8 patients. On the basis of these observations and on review of literature, it is postulated that the ventricular dilatation following an obstruction in the path of the cerebrospinal fluid flow by a tumour could be a natural defense phenomenon of the brain.

  14. Dopamine receptor regulating factor, DRRF: A zinc finger transcription factor

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    Hwang, Cheol Kyu; D'Souza, Ursula M.; Eisch, Amelia J.; Yajima, Shunsuke; Lammers, Claas-Hinrich; Yang, Young; Lee, Sang-Hyeon; Kim, Yong-Man; Nestler, Eric J.; Mouradian, M. Maral

    2001-01-01

    Dopamine receptor genes are under complex transcription control, determining their unique regional distribution in the brain. We describe here a zinc finger type transcription factor, designated dopamine receptor regulating factor (DRRF), which binds to GC and GT boxes in the D1A and D2 dopamine receptor promoters and effectively displaces Sp1 and Sp3 from these sequences. Consequently, DRRF can modulate the activity of these dopamine receptor promoters. Highest DRRF mRNA levels are found in ...

  15. Right thalamic infarction after closed head injury

    International Nuclear Information System (INIS)

    We reported a case of right thalamic infarction after a closed head injury. A 12-year-old boy was hit by an autotruck. He was semi-comatose, with left temporal scalp swelling and excoriation in the left lower limb. Three days after the accident, he exhibited left hemiparesis. CT scans on the day of the accident showed no abnormality, but on the following day, right thalamic infarction appeared. Right carotid angiography showed only an irregular vascular shadow in the cisternal segment of the right internal carotid artery. Vascular obstruction after closed head injury is rare, especially in the intracranial vessels, and several pathogeneses may be postulated. The right thalamic infarction in this case was supposed to be due to the damage of the perforators from the right posterior communicating artery and the right posterior cerebral artery, which were struck as a contre-coup by the force from the left side. (author)

  16. PT-12SURGICAL APPROACH FOR THALAMIC TUMORS

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    Smrcka, Martin; Priban, Vladimír; Brichtova, Eva; Juran, Vilem

    2014-01-01

    INTRODUCTION: Thalamic tumors are relatively rare tumors growing in a highly functional part of brain. They are more frequent in pediatric population. Their surgery is challenging and a high morbidity is possible. Relatively benign nature of many of these tumors means that an attempt for radical resection should frequently be performed. The approach has to be very carefully planned, sometimes with the help of modern diagnostic methods like DTI. The location and projection of the tumor in the thalamus plays an important role in choosing the approach. MATERIAL: We have studied a group of 12 patients with thalamic tumors treated from 2005 - 2012. There were 10 males and 2 females, age ranged from 1 - 64 years (mean 17,5 years). Transcortical approach was used 6x, transcallosal 3x, transsylvian 2x and supracerebellar infratentorial 1x. One patient is being observed only. RESULTS: Gross total resection was achieved in 6 cases, subtotal in 2 and partial in 3. There were 7 pilocytic astrocytomas, one subependymal giant cell astrocytoma, one diffuse astrocytoma G II and two glioblastomas. All patients are still alive with the mean follow-up 4 years. There was no permanent morbidity in this group. CONCLUSION: Thalamic tumors might be safely radically resected if correct approach is used. The choice of approach is based in the projection of the tumor. Smaller tumors which are not close to the thalamic surface might be followed or biopsied if there is a likelihood of its malignant nature. Oncological treatment should be reserved for malignant tumors.

  17. Global aphasia due to left thalamic hemorrhage

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    Ozeren Ali

    2006-01-01

    Full Text Available Global aphasia is an acquired language disorder characterized by severe impairments in all modalities of language. The specific sites of injury commonly include Wernike′s and Broca′s areas and result from large strokes - particularly those involving the internal carotid or middle cerebral arteries. Rarely, deep subcortical lesions may cause global aphasia. We present three cases with global aphasia due to a more rare cause: left thalamic hemorrhage. Their common feature was the large size of the hemorrhage and its extension to the third ventricule. HMPAO-SPECT in one of the cases revealed ipsilateral subcortical, frontotemporal cortical and right frontal cortical hypoperfusion. Left thalamic hemorrhage should be considered in the differential diagnosis of global aphasia.

  18. Dopaminergic Modulation of Lateral Amygdala Neuronal Activity: Differential D1 and D2 Receptor Effects on Thalamic and Cortical Afferent Inputs

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    Chang, Chun-hui; Grace, Anthony A.

    2015-01-01

    Background: In auditory fear conditioning, the lateral nucleus of the amygdala (LA) integrates a conditioned stimulus (CS) from the auditory thalamus (MGN) and the auditory association cortex (Te3) with an aversive unconditioned stimulus. The thalamic input provides a basic version of the CS, while the cortical input provides a processed representation of the stimulus. Dopamine (DA) is released in the LA under heightened arousal during the presentation of the CS. Methods: In this study we exa...

  19. Thalamic control of layer 1 circuits in prefrontal cortex

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    Cruikshank, Scott J.; Ahmed, Omar J.; Stevens, Tanya R.; Patrick, Saundra L.; Gonzalez, Amalia N.; Elmaleh, Margot; Connors, Barry W.

    2012-01-01

    Knowledge of thalamocortical (TC) processing comes mainly from studying core thalamic systems that project to middle layers of primary sensory cortices. However, most thalamic relay neurons comprise a matrix of cells that are densest in the “nonspecific” thalamic nuclei and usually target layer 1 of multiple cortical areas. A longstanding hypothesis is that matrix TC systems are crucial for regulating neocortical excitability during changing behavioral states, yet we know almost nothing about...

  20. Neurological manifestations and PET studies of the thalamic vascular lesions

    International Nuclear Information System (INIS)

    We divided 38 patients with cerebrovascular disease of the thalamus into 5 groups according to the site of the thalamic lesions as confirmed by X-ray CT and/or MRI. In 16 patients, we examined the cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) by positron emission tomography (PET). In the anteromedial thalamic lesion group, patients displayed disturbances of spontaneity, memory, reading and writing. CBF and CMRO2 were decreased in the frontal, parietal and temporal lobes on the side of the lesion. In the dorsolateral thalamic lesion group, ataxic hemiparesis was a characteristic symptom. CBF and CMRO2 were decreased in frontoparietal lobes on the side of the lesion. In the group with lesions confined to the nucleus ventralis posterioris thalami, the main symptoms were sensory disturbance, with cheiro-oral sensory syndrome being particularly evident. CBF and CMRO2 were decreased in the parietal lobe on the side of the lesion. In the group with posterolateral thalamic lesions without pulvinar involvement, patients exhibited thalamic syndrome without thalamic pain. CBF and CMRO2 were decreased in the frontoparietal and temporal lobes on the side of the lesion. In contrast, in the group with posterolateral thalamic lesions with pulvinar involvement, all patients showed thalamic pain. The decrease in CBF and CMRO2 extended to the inferomedial region of the temporal lobe in addition to the area of decreased CBF and CMRO2 observed in the group with posterolateral thalamic lesions without pulvinar involvement. Based on these results, we speculate that the neurological manifestations of thalamic vascular disease are associated with a decrease in cortical CBF and CMRO2 secondary to the thalamic lesions. (author)

  1. Distribution of dopamine D2-like receptors in the human thalamus: autoradiographic and PET studies.

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    Rieck, Richard W; Ansari, M S; Whetsell, William O; Deutch, Ariel Y; Kessler, Robert M

    2004-02-01

    The distribution of dopamine (DA) D(2)-like receptors in the human thalamus was studied using in vitro autoradiographic techniques and in vivo positron emission tomography in normal control subjects. [(125)I]Epidepride, which binds with high affinity to DA D(2) and D(3) receptors, was used in autoradiographic studies to determine the distribution and density of D(2)-like receptors, and the epidepride analogue [(18)F]fallypride positron was used for positron emission tomography studies to delineate D(2)-like receptors in vivo. Both approaches revealed a heterogeneous distribution of thalamic D(2/3) receptors, with relatively high densities in the intralaminar and midline thalamic nuclei, including the paraventricular, parataenial, paracentral, centrolateral, and centromedian/parafascicular nuclei. Moderate densities of D(2/3) sites were seen in the mediodorsal and anterior nuclei, while other thalamic nuclei expressed lower levels of D(2)-like receptors. Most thalamic nuclei that express high densities of D(2)-like receptors project to forebrain DA terminal fields, suggesting that both the thalamic neurons expressing D(2)-like receptors and the projection targets of these neurons are regulated by DA. Because the midline/intralaminar nuclei receive prominent projections from both the ascending reticular activating core and the hypothalamus, these thalamic nuclei may integrate activity conveying both interoceptive and exteroceptive information to telencephalic DA systems involved in reward and cognition. PMID:14627996

  2. Thalamic hemorrhage in ischemic anoxic encephalopathy

    International Nuclear Information System (INIS)

    The authors have performed MR imaging, CT, and US examinations in eight infants with ischemic anoxic encephalopathy (IAE). The patients were delivered at 39-42 weeks. IAE was diagnosed by reduced Apgar score, presence of respiratory difficulty, and convulsive episodes. High-signal-intensity lesions were seen in the thalamus with inversion recovery sequences and low-signal-intensity areas were seen with PS1660/193 sequences in six of the eight infants. CT and US were positive for hemorrhage in only three of the infants. Of MR imaging, CT, and US, MR imaging was the most sensitive technique for detecting thalamic hemorrhage in IAE

  3. Thalamic pain: anatomical and physiological indices of prediction.

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    Vartiainen, Nuutti; Perchet, Caroline; Magnin, Michel; Creac'h, Christelle; Convers, Philippe; Nighoghossian, Norbert; Mauguière, François; Peyron, Roland; Garcia-Larrea, Luis

    2016-03-01

    Thalamic pain is a severe and treatment-resistant type of central pain that may develop after thalamic stroke. Lesions within the ventrocaudal regions of the thalamus carry the highest risk to develop pain, but its emergence in individual patients remains impossible to predict. Because damage to the spino-thalamo-cortical system is a crucial factor in the development of central pain, in this study we combined detailed anatomical atlas-based mapping of thalamic lesions and assessment of spinothalamic integrity using quantitative sensory analysis and laser-evoked potentials in 42 thalamic stroke patients, of whom 31 had developed thalamic pain. More than 97% of lesions involved an area between 2 and 7 mm above the anterior-posterior commissural plane. Although most thalamic lesions affected several nuclei, patients with central pain showed maximal lesion convergence on the anterior pulvinar nucleus (a major spinothalamic target) while the convergence area lay within the ventral posterior lateral nucleus in pain-free patients. Both involvement of the anterior pulvinar nucleus and spinothalamic dysfunction (nociceptive thresholds, laser-evoked potentials) were significantly associated with the development of thalamic pain, whereas involvement of ventral posterior lateral nucleus and lemniscal dysfunction (position sense, graphaesthesia, pallaesthesia, stereognosis, standard somatosensory potentials) were similarly distributed in patients with or without pain. A logistic regression model combining spinothalamic dysfunction and anterior pulvinar nucleus involvement as regressors had 93% sensitivity and 87% positive predictive value for thalamic pain. Lesion of spinothalamic afferents to the posterior thalamus appears therefore determinant to the development of central pain after thalamic stroke. Sorting out of patients at different risks of developing thalamic pain may be achievable at the individual level by combining lesion localization and functional investigation of

  4. Morphological Abnormalities of Thalamic Subnuclei in Migraine

    DEFF Research Database (Denmark)

    Magon, Stefano; May, Arne; Stankewitz, Anne;

    2015-01-01

    UNLABELLED: The thalamus contains third-order relay neurons of the trigeminal system, and animal models as well as preliminary imaging studies in small cohorts of migraine patients have suggested a role of the thalamus in headache pathophysiology. However, larger studies using advanced imaging...... techniques in substantial patient populations are lacking. In the present study, we investigated changes of thalamic volume and shape in a large multicenter cohort of patients with migraine. High-resolution T1-weighted MRI data acquired at 3 tesla in 131 patients with migraine (38 with aura; 30.8 ± 9 years...... a fully automated multiatlas approach. Deformation-based shape analysis was performed to localize surface abnormalities. Differences between patients with migraine and healthy subjects were assessed using an ANCOVA model. After correction for multiple comparisons, performed using the false discovery...

  5. Fatal thalamic abscess secondary to dental infection.

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    Basyuni, Shadi; Sharma, Valmiki; Santhanam, Vijay; Ferro, Ashley

    2015-01-01

    We present the case of poor neurological recovery and subsequent death secondary to a thalamic abscess in a 53-year-old man. This patient initially presented with sudden dysarthria and left hemiparesis while driving. Neuroimaging showed a multilobular abscess involving the right thalamus with oedema extending to the basal ganglionic region and brainstem. The source of the abscess was initially unknown and it required draining multiple times while the different causes were being explored. The patient's neurological state along with intubation made for a difficult and inconclusive oral examination. It was only after neuroimaging included tooth-bearing areas that it became evident that this patient had extensive periodontal disease with multiple areas of periapical radiolucencies. The patient underwent complete dental clearance alongside repeated drainage of the abscess. Despite initial postoperative improvement, the patient never recovered from the neurological damage and died 3 weeks later. PMID:26678690

  6. CT classification of small thalamic hemorrhages

    International Nuclear Information System (INIS)

    The thalamus is located deep in the cerebral hemispheres, and most of its nuclei have reciprocal fiber connections with specific areas over the cerebral cortex. Localized lesions in the thalamus, therefore, can cause specific neurological deficits, depending on their locations. From this point of view, we reviewed 110 cases, admitted over the past 7 years, with thalamic hemorrhages 37 (34%) of which were small hematomas less than 2 cm in diameter. These small hematomas could be divided into 4 types depending on their locations as follows: antero-lateral type, postero-lateral type, medial type, and dorsal type. Each type had the peculiar clinical features described below: 1) Postero-lateral Type (PL type, 28 cases, 76%): The original symptom was a sudden onset of moderate to severe sensori-motor deficits in most cases. The patients were mostly alert or only slightly confused. 2) Antero-lateral Type (AL type, 4 cases, 11%): The patients of this type first presented with sensori-motor disturbance and prefrontal signs. Both were generally mild and often disappeared early. 3) Medial Type (M type, 3 cases, 8%): The main symptom at onset was either a disturbance of consciousness or dementia. 4) Dorsal Type (D type, 2 cases, 5%): One patient with a right thalamic hematoma of this type showed geographical agnosia and visuo-constructive apraxia. The other patient, with a left-sided hematoma, exhibited transient clumsiness of the right hand and mild dysphasia. In our experience, the above classification of small hematomas clearly delineated the clinical symptoms and neurological signs of the different types; therefore, the symptoms and signs in larger hematoma could be explained by a combination of those of each type. (J.P.N.)

  7. Einstein's Boxes

    CERN Document Server

    Norsen, T

    2005-01-01

    At the 1927 Solvay conference, Einstein presented a thought experiment intended to demonstrate the incompleteness of the quantum mechanical description of reality. In the following years, the thought experiment was picked up and modified by Einstein, de Broglie, and several other commentators into a simple scenario involving the splitting in half of the wave function of a single particle in a box. In this paper we collect together several formulations of this thought experiment from the existing literature; analyze and assess it from the point of view of the Einstein-Bohr debates, the EPR dilemma, and Bell's theorem; and generally lobby for Einstein's Boxes taking its rightful place alongside similar but historically better-known quantum mechanical thought experiments such as EPR and Schroedinger's Cat.

  8. Einstein's Boxes

    OpenAIRE

    Norsen, Travis

    2004-01-01

    At the 1927 Solvay conference, Einstein presented a thought experiment intended to demonstrate the incompleteness of the quantum mechanical description of reality. In the following years, the thought experiment was picked up and modified by Einstein, de Broglie, and several other commentators into a simple scenario involving the splitting in half of the wave function of a single particle in a box. In this paper we collect together several formulations of this thought experiment from the exist...

  9. MRI of paramedian thalamic stroke with sleep disturbance

    Energy Technology Data Exchange (ETDEWEB)

    Loevblad, K.O. [MRI Unit, Radiology Department, AN-234, Beth Israel Hospital, 330 Brookline Avenue, Boston, MA 02215 (United States)]|[Department of Neuroradiology, Inselspital, University of Bern (Switzerland); Bassetti, C.; Mathis, J. [Department of Neurology, Inselspital, University of Bern (Switzerland); Schroth, G. [Department of Neuroradiology, Inselspital, University of Bern (Switzerland)

    1997-10-01

    The paramedian thalamus is believed to play an important role in the regulation of sleep, and disturbances of sleep regulation are known to occur in paramedian thalamic stroke (PTS). We examined 12 consecutive patients with PTS and sleep disturbance by MRI. Two distinct groups of patients could be defined: six presenting with severe hypersomnia (group 1) and six with slight sleepiness (group 2). On MRI, all patients had ischaemic lesions involving the paramedian thalamic nuclei, the centre of the lesions being the dorsomedial and centromedial thalamic nuclei. In group 1 the lesions were bilateral, butterfly-shaped infarcts involving the paramedian nuclei (three cases), or unilateral with an extension into the subthalamic nuclei. In group 2 the lesions were unilateral and limited to the paramedian nuclei, mainly the dorsomedial nucleus. Bilateral lesions can be attributed to a common origin in some cases for both paramedian thalamic arteries and the mesencephalic arteries. (orig.). With 5 figs.

  10. MRI of paramedian thalamic stroke with sleep disturbance

    International Nuclear Information System (INIS)

    The paramedian thalamus is believed to play an important role in the regulation of sleep, and disturbances of sleep regulation are known to occur in paramedian thalamic stroke (PTS). We examined 12 consecutive patients with PTS and sleep disturbance by MRI. Two distinct groups of patients could be defined: six presenting with severe hypersomnia (group 1) and six with slight sleepiness (group 2). On MRI, all patients had ischaemic lesions involving the paramedian thalamic nuclei, the centre of the lesions being the dorsomedial and centromedial thalamic nuclei. In group 1 the lesions were bilateral, butterfly-shaped infarcts involving the paramedian nuclei (three cases), or unilateral with an extension into the subthalamic nuclei. In group 2 the lesions were unilateral and limited to the paramedian nuclei, mainly the dorsomedial nucleus. Bilateral lesions can be attributed to a common origin in some cases for both paramedian thalamic arteries and the mesencephalic arteries. (orig.). With 5 figs

  11. Deficits in human visual spatial attention following thalamic lesions.

    OpenAIRE

    Rafal, R D; Posner, M I

    1987-01-01

    There has been speculation concerning the role that thalamic nuclei play in directing attention to locations in visual space [Crick, F. (1984) Proc. Natl. Acad. Sci. USA 81, 4586-4590]. We measured covert shifts of visual attention in three patients with unilateral thalamic hemorrhages shortly after the lesion and after a 6-month recovery period. The experiment measured reaction time to targets that occurred at locations to which attention had been cued (valid trials) or at a currently unatte...

  12. Thalamic Circuit Diversity: Modulation of the Driver/Modulator Framework

    Directory of Open Access Journals (Sweden)

    Martha E Bickford

    2016-01-01

    Full Text Available The idea that dorsal thalamic inputs can be divided into drivers, which provide the primary excitatory drive for the relay of information to cortex, and modulators, which alter the gain of signal transmission, has provided a valuable organizing principle for the study of thalamic function. This view further promoted the identification of first order and higher order thalamic nuclei, based on the origin of their driving inputs. Since the introduction of this influential terminology, a number of studies have revealed the existence of a wide variety of thalamic organizational schemes. For example, some thalamic nuclei are not innervated by typical driver inputs, but instead receive input from terminals which exhibit features distinct from those of either classic drivers or modulators. In addition, many thalamic nuclei contain unique combinations of convergent first order, higher order, and/or other driver-like inputs that do not conform with the driver/modulator framework. The assortment of synaptic arrangements identified in the thalamus are reviewed and discussed from the perspective that this organizational diversity can dramatically increase the computational capabilities of the thalamus, reflecting its essential roles in sensory, motor, and sensory-motor circuits.

  13. Midline thalamic neurons are differentially engaged during hippocampus network oscillations.

    Science.gov (United States)

    Lara-Vásquez, Ariel; Espinosa, Nelson; Durán, Ernesto; Stockle, Marcelo; Fuentealba, Pablo

    2016-01-01

    The midline thalamus is reciprocally connected with the medial temporal lobe, where neural circuitry essential for spatial navigation and memory formation resides. Yet, little information is available on the dynamic relationship between activity patterns in the midline thalamus and medial temporal lobe. Here, we report on the functional heterogeneity of anatomically-identified thalamic neurons and the differential modulation of their activity with respect to dorsal hippocampal rhythms in the anesthetized mouse. Midline thalamic neurons expressing the calcium-binding protein calretinin, irrespective of their selective co-expression of calbindin, discharged at overall low levels, did not increase their activity during hippocampal theta oscillations, and their firing rates were inhibited during hippocampal sharp wave-ripples. Conversely, thalamic neurons lacking calretinin discharged at higher rates, increased their activity during hippocampal theta waves, but remained unaffected during sharp wave-ripples. Our results indicate that the midline thalamic system comprises at least two different classes of thalamic projection neuron, which can be partly defined by their differential engagement by hippocampal pathways during specific network oscillations that accompany distinct behavioral contexts. Thus, different midline thalamic neuronal populations might be selectively recruited to support distinct stages of memory processing, consistent with the thalamus being pivotal in the dialogue of cortical circuits. PMID:27411890

  14. Dopamine receptor regulating factor, DRRF: a zinc finger transcription factor.

    Science.gov (United States)

    Hwang, C K; D'Souza, U M; Eisch, A J; Yajima, S; Lammers, C H; Yang, Y; Lee, S H; Kim, Y M; Nestler, E J; Mouradian, M M

    2001-06-19

    Dopamine receptor genes are under complex transcription control, determining their unique regional distribution in the brain. We describe here a zinc finger type transcription factor, designated dopamine receptor regulating factor (DRRF), which binds to GC and GT boxes in the D1A and D2 dopamine receptor promoters and effectively displaces Sp1 and Sp3 from these sequences. Consequently, DRRF can modulate the activity of these dopamine receptor promoters. Highest DRRF mRNA levels are found in brain with a specific regional distribution including olfactory bulb and tubercle, nucleus accumbens, striatum, hippocampus, amygdala, and frontal cortex. Many of these brain regions also express abundant levels of various dopamine receptors. In vivo, DRRF itself can be regulated by manipulations of dopaminergic transmission. Mice treated with drugs that increase extracellular striatal dopamine levels (cocaine), block dopamine receptors (haloperidol), or destroy dopamine terminals (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) show significant alterations in DRRF mRNA. The latter observations provide a basis for dopamine receptor regulation after these manipulations. We conclude that DRRF is important for modulating dopaminergic transmission in the brain. PMID:11390978

  15. Thalamic mediation of hypoxic respiratory depression in lambs.

    Science.gov (United States)

    Koos, Brian J; Rajaee, Arezoo; Ibe, Basil; Guerra, Catalina; Kruger, Lawrence

    2016-04-01

    Immaturity of respiratory controllers in preterm infants dispose to recurrent apnea and oxygen deprivation. Accompanying reductions in brain oxygen tensions evoke respiratory depression, potentially exacerbating hypoxemia. Central respiratory depression during moderate hypoxia is revealed in the ventilatory decline following initial augmentation. This study determined whether the thalamic parafascicular nuclear (Pf) complex involved in adult nociception and sensorimotor regulation (Bentivoglio M, Balerecia G, Kruger L.Prog Brain Res87: 53-80, 1991) also becomes a postnatal controller of hypoxic ventilatory decline. Respiratory responses to moderate isocapnic hypoxia were studied in conscious lambs. Hypoxic ventilatory decline was compared with peak augmentation. Pf and/or adjacent thalamic structures were destroyed by the neuron-specific toxin ibotenic acid (IB). IB lesions involving the thalamic Pf abolished hypoxic ventilatory decline. Lesions of adjacent thalamic nuclei that spared Pf and control injections of vehicle failed to blunt hypoxic respiratory depression. Our findings reveal that the thalamic Pf region is a critical controller of hypoxic ventilatory depression and thus a key target for exploring molecular concomitants of forebrain pathways regulating hypoxic ventilatory depression in early development. PMID:26818057

  16. Global suppression of electrocortical activity in unilateral perinatal thalamic stroke.

    LENUS (Irish Health Repository)

    Kharoshankaya, Liudmila

    2014-07-01

    We present an unusual case of persistent generalized electroencephalography (EEG) suppression and right-sided clonic seizures in a male infant born at 40(+2) weeks\\' gestation, birthweight 3240g, with an isolated unilateral thalamic stroke. The EEG at 13 hours after birth showed a generalized very low amplitude background pattern, which progressed to frequent electrographic seizures over the left hemisphere. The interictal background EEG pattern remained grossly abnormal over the next 48 hours, showing very low background amplitudes (<10μV). Magnetic resonance imaging revealed an isolated acute left-sided thalamic infarction. This is the first description of severe global EEG suppression caused by an isolated unilateral thalamic stroke and supports the role of the thalamus as the control centre for cortical electrical activity.

  17. Positive Correlation between Severity of Blepharospasm and Thalamic Glucose Metabolism.

    Science.gov (United States)

    Murai, Hideki; Suzuki, Yukihisa; Kiyosawa, Motohiro; Wakakura, Masato; Mochizuki, Manabu; Ishiwata, Kiichi; Ishii, Kenji

    2011-01-01

    A 43-year-old woman with drug-related blepharospasm was followed up for 22 months. She had undergone etizolam treatment for 19 years for indefinite complaints. We examined her cerebral glucose metabolism 5 times (between days 149 and 688 since presentation), using positron emission tomography, and identified regions of interest in the thalamus, caudate nucleus, putamen, and primary somatosensory area on both sides. The severity of the blepharospasm was evaluated by PET scanning using the Wakakura classification. Sixteen women (mean age 42.4 ± 11.7 years) were examined as normal controls. The thalamic glucose metabolism in our patient was significantly increased on days 149, 212, and 688. The severity of the blepharospasm was positively correlated with the thalamic glucose metabolism, suggesting that the severity of blepharospasms reflects thalamic activity. PMID:22110436

  18. Effects of thalamic deep brain stimulation on spontaneous language production.

    Science.gov (United States)

    Ehlen, Felicitas; Vonberg, Isabelle; Kühn, Andrea A; Klostermann, Fabian

    2016-08-01

    The thalamus is thought to contribute to language-related processing, but specifications of this notion remain vague. An assessment of potential effects of thalamic deep brain stimulation (DBS) on spontaneous language may help to delineate respective functions. For this purpose, we analyzed spontaneous language samples from thirteen (six female / seven male) patients with essential tremor treated with DBS of the thalamic ventral intermediate nucleus (VIM) in their respective ON vs. OFF conditions. Samples were obtained from semi-structured interviews and examined on multidimensional linguistic levels. In the VIM-DBS ON condition, participants used a significantly higher proportion of paratactic as opposed to hypotactic sentence structures. This increase correlated negatively with the change in the more global cognitive score, which in itself did not change significantly. In conclusion, VIM-DBS appears to induce the use of a simplified syntactic structure. The findings are discussed in relation to concepts of thalamic roles in language-related cognitive behavior. PMID:27267813

  19. Intrinsic properties and neuropharmacology of midline paraventricular thalamic nucleus neurons.

    Directory of Open Access Journals (Sweden)

    Miloslav Kolaj

    2014-04-01

    Full Text Available Neurons in the midline and intralaminar thalamic nuclei are components of an interconnected brainstem, limbic and prefrontal cortex neural network that is engaged during arousal, vigilance, motivated and addictive behaviors, and stress. To better understand the cellular mechanisms underlying these functions, here we review some of the recently characterized electrophysiological and neuropharmacological properties of neurons in the paraventricular thalamic nucleus (PVT, derived from whole cell patch clamp recordings in acute rat brain slice preparations. PVT neurons display firing patterns and ionic conductances (IT and IH that exhibit significant diurnal change. Their resting membrane potential is maintained by various ionic conductances that include inward rectifier (Kir, hyperpolarization-activated nonselective cation (HCN and TWIK-related acid sensitive (TASK K+ channels. Firing patterns are regulated by high voltage-activated (HVA and low voltage-activated (LVA Ca2+ conductances. Moreover, transient receptor potential (TRP-like nonselective cation channels together with Ca2+- and Na+-activated K+ conductances (KCa; KNa contribute to unique slow afterhyperpolarizing potentials (sAHPs that are generally not detectable in lateral thalamic or reticular thalamic nucleus neurons. We also report on receptor-mediated actions of GABA, glutamate, monoamines and several neuropeptides: arginine vasopressin, gastrin-releasing peptide, thyrotropin releasing hormone and the orexins (hypocretins. This review represents an initial survey of intrinsic and transmitter-sensitive ionic conductances that are deemed to be unique to this population of midline thalamic neurons, information that is fundamental to an appreciation of the role these thalamic neurons may play in normal central nervous system (CNS physiology and in CNS disorders that involve the dorsomedial thalamus.

  20. A thalamic reticular networking model of consciousness

    Directory of Open Access Journals (Sweden)

    Min Byoung-Kyong

    2010-03-01

    Full Text Available Abstract [Background] It is reasonable to consider the thalamus a primary candidate for the location of consciousness, given that the thalamus has been referred to as the gateway of nearly all sensory inputs to the corresponding cortical areas. Interestingly, in an early stage of brain development, communicative innervations between the dorsal thalamus and telencephalon must pass through the ventral thalamus, the major derivative of which is the thalamic reticular nucleus (TRN. The TRN occupies a striking control position in the brain, sending inhibitory axons back to the thalamus, roughly to the same region where they receive afferents. [Hypotheses] The present study hypothesizes that the TRN plays a pivotal role in dynamic attention by controlling thalamocortical synchronization. The TRN is thus viewed as a functional networking filter to regulate conscious perception, which is possibly embedded in thalamocortical networks. Based on the anatomical structures and connections, modality-specific sectors of the TRN and the thalamus appear to be responsible for modality-specific perceptual representation. Furthermore, the coarsely overlapped topographic maps of the TRN appear to be associated with cross-modal or unitary conscious awareness. Throughout the latticework structure of the TRN, conscious perception could be accomplished and elaborated through accumulating intercommunicative processing across the first-order input signal and the higher-order signals from its functionally associated cortices. As the higher-order relay signals run cumulatively through the relevant thalamocortical loops, conscious awareness becomes more refined and sophisticated. [Conclusions] I propose that the thalamocortical integrative communication across first- and higher-order information circuits and repeated feedback looping may account for our conscious awareness. This TRN-modulation hypothesis for conscious awareness provides a comprehensive rationale regarding

  1. Lateral and Anterior Thalamic Lesions Impair Independent Memory Systems

    Science.gov (United States)

    Mitchell, Anna S.; Dalrymple-Alford, John C.

    2006-01-01

    Damage to the medial region of the thalamus, both in clinical cases (e.g., patients with infarcts or the Korsakoff's syndrome) and animal lesion models, is associated with variable amnesic deficits. Some studies suggest that many of these memory deficits rely on the presence of lateral thalamic lesions (LT) that include the intralaminar nuclei,…

  2. DISC1 Ser704Cys impacts thalamic-prefrontal connectivity.

    Science.gov (United States)

    Liu, Bing; Fan, Lingzhong; Cui, Yue; Zhang, Xiaolong; Hou, Bing; Li, Yonghui; Qin, Wen; Wang, Dawei; Yu, Chunshui; Jiang, Tianzi

    2015-01-01

    The Disrupted-in-Schizophrenia 1 (DISC1) gene has been thought as a putative susceptibility gene for various psychiatric disorders, and DISC1 Ser704Cys is associated with variations of brain morphology and function. Moreover, our recent diffusion magnetic resonance imaging (dMRI) study reported that DISC1 Ser704Cys was associated with information transfer efficiency in the brain anatomical network. However, the effects of the DISC1 gene on functional brain connectivity and networks, especially for thalamic-prefrontal circuit, which are disrupted in various psychiatric disorders, are largely unknown. Using a functional connectivity density (FCD) mapping method based on functional magnetic resonance imaging data in a large sample of healthy Han Chinese subjects, we first investigated the association between DISC1 Ser704Cys and short- and long-range FCD hubs. Compared with Ser homozygotes, Cys-allele individuals had increased long-range FCD hubs in the bilateral thalami. The functional and anatomical connectivity of the thalamus to the prefrontal cortex was further analyzed. Significantly increased thalamic-prefrontal functional connectivity and decreased thalamic-prefrontal anatomical connectivity were found in DISC1 Cys-allele carriers. Our findings provide consistent evidence that the DISC1 Ser704Cys polymorphism influences the thalamic-prefrontal circuits in humans and may provide new insights into the neural mechanisms that link DISC1 and the risk for psychiatric disorders. PMID:24146131

  3. Thalamic T-type Ca2+ channels and NREM sleep

    OpenAIRE

    Crunelli, Vincenzo; Cope, David W.; Hughes, Stuart W.

    2006-01-01

    T-type Ca2+ channels play a number of different and pivotal roles in almost every type of neuronal oscillation expressed by thalamic neurones during non-Rapid Eye Movement (NREM) sleep, including those underlying sleep theta waves, the K-complex and the slow (

  4. Outcome After Pituitary Radiosurgery for Thalamic Pain Syndrome

    International Nuclear Information System (INIS)

    Purpose: To evaluate outcomes after pituitary radiosurgery in patients with post-stroke thalamic pain syndrome. Methods and Materials: From 2002 to 2006, 24 patients with thalamic pain syndrome underwent pituitary radiosurgery at Tokyo Women's Medical University and were followed at least 12 months thereafter. The radiosurgical target was defined as the pituitary gland and its connection with the pituitary stalk. The maximum dose varied from 140 to 180 Gy. Mean follow-up after treatment was 35 months (range, 12-48 months). Results: Initial pain reduction, usually within 48 h after radiosurgery, was marked in 17 patients (71%). However, in the majority of cases the pain recurred within 6 months after treatment, and at the time of the last follow-up examination durable pain control was marked in only 5 patients (21%). Ten patients (42%) had treatment-associated side effects. Anterior pituitary abnormalities were marked in 8 cases and required hormonal replacement therapy in 3; transient diabetes insipidus was observed in 2 cases, transient hyponatremia in 1, and clinical deterioration due to increase of the numbness severity despite significant reduction of pain was seen once. Conclusions: Pituitary radiosurgery for thalamic pain results in a high rate of initial efficacy and is accompanied by acceptable morbidity. It can be used as a primary minimally invasive management option for patients with post-stroke thalamic pain resistant to medical therapy. However, in the majority of cases pain recurrence occurs within 1 year after treatment

  5. Dopamine transporters govern diurnal variation in extracellular dopamine tone

    OpenAIRE

    Ferris, Mark J.; España, Rodrigo A.; Locke, Jason L.; Konstantopoulos, Joanne K.; Rose, Jamie H.; Chen, Rong; Jones, Sara R.

    2014-01-01

    The mechanism for diurnal (i.e., light/dark) oscillations in extracellular dopamine tone in mesolimbic and nigrostriatal systems is unknown. This is because, unlike other neurotransmitter systems, variation in dopamine tone does not correlate with variation in dopamine cell firing. The current research pinpoints the dopamine transporter as a critical governor of diurnal variation in both extracellular dopamine tone and the intracellular availability of releasable dopamine. These data describe...

  6. Clinical patterns of speech-language disorders in thalamic aphasias

    OpenAIRE

    Kuljić-Obradović Dragana; Ocić Gordana G.

    2002-01-01

    The aim of this study was to investigate the characteristic symptom cluster and the course of aphasia in 12 patients with single left thalamic lesion verified by CAT scan. The testing of language disorder was performed by standard linguistic tests for aphasia in the acute stage and one month after the insult. Although this clinical syndrome varied greatly it was possible to point out some common characteristics. Spontaneous speech was fluent, easily articulated, grammatically correct, with pr...

  7. Bilateral paramedian thalamic artery infarcts: report of eight cases.

    OpenAIRE

    Gentilini, M.; De Renzi, E; Crisi, G

    1987-01-01

    Eight consecutive patients with CT scan evidence of a bilateral infarct in the territory of the paramedian thalamic artery are reported. In seven cases the infarct also extended to the territory of the polar artery. The main symptoms were: disorder of vigilance which cleared in a few days, and hypersomnolence which lasted longer and in two patients was still present a year later; amnesia, detectable clinically in four patients and only with tests in two patients, which persisted in one patien...

  8. Bilateral thalamic infarction with psychiatric symptoms: case report

    OpenAIRE

    Betül Tekin Güveli; Ahmet Nalbant; Metin Dedei Daryan; Batuhan Kara; Cengiz Dayan; Dilek Ataklı

    2016-01-01

    Introduction: Thalamus is a mass of gray matter, which plays a role in the transmission of sensory and motor information to the primary sensory and motor centers of the cerebral cortex, cerebellum and basal ganglia. Vascular lesions of thalamus may occur in different syndromes depending on the affected nuclei. In this report, a case with acute evolving personality and behavior changes and detected bilateral thalamic infarction will be presented. Case: A 40-year-old male patient was brought to...

  9. 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.

  10. Injury of the mammillothalamic tract in patients with thalamic hemorrhage

    Directory of Open Access Journals (Sweden)

    Sung Ho Jang

    2014-04-01

    Full Text Available Objective:Injury of the mammillothalamic tract(MTT has been suggested as one of the plausible pathogenic mechanisms of memory impairment in patients with thalamic hemorrhage; however, it has not been clearly demonstrated so far. We attempted to investigate whether injury of the MTT documented by diffusion tensor tractography(DTT following thalamic hemorrhage correlates with cognitive impairment. Methods:We recruited 22 patients with a thalamic hemorrhage and 20 control subjects. MTTs were reconstructed using the probabilistic tractography method. Patients were classified into two subgroups: Reconstructed group-patients whose MTT was reconstructed in the affected hemisphere and Non-reconstructed group-patients whose MTT was not reconstructed.Results:MTT was reconstructed in five(22.7%,Reconstructed group patients in the affected hemisphere and was not reconstructed in the remaining 17 patients(77.3%,Non-reconstructed group. In addition, the MTT was not reconstructed even in the unaffected hemisphere in four patients(23.5% in Non-reconstructed group. Fractional anisotropy and mean diffusivity values of the affected hemisphere in Reconstructed group also did not show significant differences from those in the unaffected hemisphere of Reconstructed group and the control group(p>0.05. However, the tract volume of the affected hemisphere in Reconstructed group was significantly lower than that of the unaffected hemisphere in Reconstructed group and the control group(pConclusion:A large portion of patients with thalamic hemorrhage appeared to suffer severe injury of the ipsi-lesional MTT(77.3% and 18.2% of these patients appeared to suffer severe injury even in the contra-lesional MTT. In addition, the remaining 22.7% of patients who had preserved integrity of the ipsi-lesional MTT appeared to suffer partial injury of the ipsi-lesional MTT.

  11. State-dependent architecture of thalamic reticular sub-networks

    OpenAIRE

    Halassa, Michael M.; Chen, Zhe; Wimmer, Ralf D.; Brunetti, Philip M.; Zhao, Shengli; Zikopoulos, Basilis; Wang, Fan; Brown, Emery N.; Wilson, Matthew A

    2014-01-01

    Behavioral state is known to influence interactions between thalamus and cortex, which are important for sensation, action and cognition. The thalamic reticular nucleus (TRN) is hypothesized to regulate thalamo-cortical transmission, but the underlying functional architecture of this process and its state-dependence are unknown. By combining the first TRN ensemble recording with psychophysics and connectivity-based optogenetic tagging, we find that the TRN is composed of distinct sub-networks...

  12. Laryngeal (Voice Box) Cancer

    Science.gov (United States)

    ... Meeting Calendar Find an ENT Doctor Near You Voice Box (Laryngeal) Cancer Voice Box (Laryngeal) Cancer Patient Health Information News media ... laryngeal cancer can be severe with respect to voice, breathing, or swallowing. It is fundamentally a preventable ...

  13. Thalamic amplification of sensory input in experimental diabetes.

    Science.gov (United States)

    Freeman, Oliver J; Evans, Mathew H; Cooper, Garth J S; Petersen, Rasmus S; Gardiner, Natalie J

    2016-07-01

    Diabetic neuropathy is a common, and often debilitating, secondary complication of diabetes mellitus. As pain, hypersensitivity and paraesthesias present in a distal-proximal distribution, symptoms are generally believed to originate from damaged afferents within the peripheral nervous system. Increasing evidence suggests altered processing within the central nervous system in diabetic neuropathy contributes towards somatosensory dysfunction, but whether the accurate coding and relay of peripherally encoded information through the central nervous system is altered in diabetes is not understood. Here, we applied the strengths of the rodent whisker-barrel system to study primary afferent-thalamic processing in diabetic neuropathy. We found that neurons in the thalamic ventral posteromedial nucleus from rats with experimental diabetic neuropathy showed increased firing to precisely graded, multidirectional whisker deflection compared to non-diabetic rats. This thalamic hyperactivity occurred without any overt primary afferent dysfunction, as recordings from the trigeminal ganglion showed these primary afferents to be unaffected by diabetes. These findings suggest that central amplification can substantially transform ascending sensory input in diabetes, even in the absence of a barrage of ectopic primary afferent activity. PMID:27152754

  14. Selective Thalamic Innervation of Rat Frontal Cortical Neurons.

    Science.gov (United States)

    Shigematsu, Naoki; Ueta, Yoshifumi; Mohamed, Alsayed A; Hatada, Sayuri; Fukuda, Takaichi; Kubota, Yoshiyuki; Kawaguchi, Yasuo

    2016-06-01

    Most glutamatergic inputs in the neocortex originate from the thalamus or neocortical pyramidal cells. To test whether thalamocortical afferents selectively innervate specific cortical cell subtypes and surface domains, we investigated the distribution patterns of thalamocortical and corticocortical excitatory synaptic inputs in identified postsynaptic cortical cell subtypes using intracellular and immunohistochemical staining combined with confocal laser scanning and electron microscopic observations in 2 thalamorecipient sublayers, lower layer 2/3 (L2/3b) and lower layer 5 (L5b) of rat frontal cortex. The dendrites of GABAergic parvalbumin (PV) cells preferentially received corticocortical inputs in both sublayers. The somata of L2/3b PV cells received thalamic inputs in similar proportions to the basal dendritic spines of L2/3b pyramidal cells, whereas L5b PV somata were mostly innervated by cortical inputs. The basal dendrites of L2/3b pyramidal and L5b corticopontine pyramidal cells received cortical and thalamic glutamatergic inputs in proportion to their local abundance, whereas crossed-corticostriatal pyramidal cells in L5b exhibited a preference for thalamic inputs, particularly in their distal dendrites. Our data demonstrate an exquisite selectivity among thalamocortical afferents in which synaptic connectivity is dependent on the postsynaptic neuron subtype, cortical sublayer, and cell surface domain. PMID:26045568

  15. Presentation of bilateral thalamic infarction on CT, MRI and PET

    International Nuclear Information System (INIS)

    Paramedian thalamic structures and part of the upper midbrain are frequently supplied by posterior thalamoperforating arteries originating from one common trunk. Local impairment of flow entails a bilateral more or less symmetric thalamic infarction with varying involvement of the midbrain. Diagnosis usually can neither be firmly established on clinical grounds nor by angiography alone. In the present series of four patients the two cases observed before the CT era were diagnosed correctly only at autopsy. Only one patient presented the classical syndrome of hypersomnia, thalamic dementia, and occulomotor nerve paralysis, while in the others clinical signs probably were masked by serious impairment of consciousness. In two cases X-ray computed tomography and magnetic resonance tomography (one case) afforded precise definition of infarct localization and size. Infarction in the described terminal vascular supply territory may be detected more often by these modern diagnostic techniques than anticipated from previous clinico-pathological experience as the underlying cause of coma in the elderly - a group of patients at particular risk for low-flow states. Positron emission tomography repeat studies with 18F-2-fluorodeoxyglucose (one case) revealed complex disturbances of brain energy metabolism; correlative analysis of clinical function and metabolic patterns during the course of the disease may not only advance individual prognostication but also contribute to the understanding and localization of brain function. (orig.)

  16. The role of thalamic population synchrony in the emergence of cortical feature selectivity.

    OpenAIRE

    Kelly, Sean T.; Jens Kremkow; Jianzhong Jin; Yushi Wang; Qi Wang; Jose-Manuel Alonso; Stanley, Garrett B.

    2014-01-01

    In a wide range of studies, the emergence of orientation selectivity in primary visual cortex has been attributed to a complex interaction between feed-forward thalamic input and inhibitory mechanisms at the level of cortex. Although it is well known that layer 4 cortical neurons are highly sensitive to the timing of thalamic inputs, the role of the stimulus-driven timing of thalamic inputs in cortical orientation selectivity is not well understood. Here we show that the synchronization of th...

  17. The Role of Thalamic Population Synchrony in the Emergence of Cortical Feature Selectivity

    OpenAIRE

    Kelly, Sean T.; Kremkow, Jens; Jin, Jianzhong; Wang, Yushi; Wang, Qi; Alonso, Jose-Manuel; Stanley, Garrett B.

    2014-01-01

    In a wide range of studies, the emergence of orientation selectivity in primary visual cortex has been attributed to a complex interaction between feed-forward thalamic input and inhibitory mechanisms at the level of cortex. Although it is well known that layer 4 cortical neurons are highly sensitive to the timing of thalamic inputs, the role of the stimulus-driven timing of thalamic inputs in cortical orientation selectivity is not well understood. Here we show that the synchronization of th...

  18. Postnatal maturational properties of rat parafascicular thalamic neurons recorded in vitro

    OpenAIRE

    PHELAN, K.D.; Mahler, H.R.; DEERE, T.; CROSS, C.B.; GOOD, C.; Garcia-Rill, E.

    2005-01-01

    Thalamic relay neurons have homogeneous, adult-like firing properties and similar morphology by 12 days postnatally (PN 12). Parafascicular (Pf) neurons have a different morphology compared with typical thalamic relay neurons, but the development of their electrophysiological properties is not well studied. Intracellular recordings in PN 12–50 Pf neurons revealed several heterogeneous firing patterns different from those in thalamic relay neurons. Two types of cells were identified: Type I ce...

  19. Dopamins renale virkninger

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal

    1990-01-01

    which are possible not exclusively secondary to alterations in the renal haemodynamics but may also be due to specific tubular effects. Recent investigations have revealed that dopamine does not increase RBF and GFR in patients with chronic renal failure if GFR is less than 60 ml/minute. Dopamine in low...... doses is frequently employed in cases of acute oliguric renal failure but the results available concerning the therapeutic effect are frequently retrospective and uncontrolled. The results suggest that early treatment with 1-3 micrograms/kg/min dopamine combined with furosemide can postpone or possibly......Dopamine is an endogenic catecholamine which, in addition to being the direct precursor of noradrenaline, has also an effect on peripheral dopaminergic receptors. These are localized mainly in the heart, splanchnic nerves and the kidneys. Dopamine is produced in the kidneys and the renal metabolism...

  20. What does a comparison of the alcoholic Korsakoff syndrome and thalamic infarction tell us about thalamic amnesia?

    Science.gov (United States)

    Kopelman, Michael D

    2015-07-01

    In this review, the clinical, neuropsychological, and neuroimaging findings in the alcoholic Korsakoff syndrome and in thalamic amnesia, resulting from focal infarction, are compared. In both disorders, there is controversy over what is the critical site for anterograde amnesia to occur-damage to the anterior thalamus/mammillo-thalamic tract has most commonly been cited, but damage to the medio-dorsal nuclei has also been advocated. Both syndromes show 'core' features of an anterograde amnesic syndrome; but retrograde amnesia is generally much more extensive (going back many years or decades) in the Korsakoff syndrome. Likewise, spontaneous confabulation occurs more commonly in the Korsakoff syndrome, although seen in only a minority of chronic cases. These differences are attributed to the greater prevalence of frontal atrophy and frontal damage in Korsakoff cases. PMID:25218758

  1. Hypertensive thalamic hematoma treated by CT stereotactic evacuation (with two cases reports)

    International Nuclear Information System (INIS)

    Objective: To investigate new surgical method to treat hypertensive thalamic hematoma. Methods: Two medial-degree coma patients with hypertensive thalamic hematoma were treated by CT stereotactic evacuation. Results: One week after operation the two patients regained consciousness. The function of paraplegic appendage restored partly, and one patient could take care of himself. Conclusion: CT stereotactic evacuation to treat hypertensive thalamic hematoma has the advantages of small trauma, little complication and good clinical results. The authors suggest that it be selected firstly in treating hypertensive thalamic hematoma

  2. Decreased striatal and enhanced thalamic dopaminergic responsivity in detoxified cocaine abusers

    Energy Technology Data Exchange (ETDEWEB)

    Volkow, N.D.; Wang, G.J.; Fowler, J.S. [Brookhaven National Lab., Stony Brook, NY (United States)] [and others

    1997-05-01

    It has been hypothesized that cocaine addiction could result from decreased brain dopamine (DA) function. However, little is known about changes in (DA) neurotransmission in human cocaine addiction. We used PET and [C-11]raclopride, a DA D2 receptor ligand sensitive to competition with endogenous DA, to measure relative changes in extracellular DA induced by methylphenidate (MP) in 20 cocaine abusers (3-6 weeks after cocaine discontinuation) and 23 controls. MP did not affect the transport of [C-11]raclopride from blood to brain (K1); however it induced a significant reduction in DA D2 receptor availability (Bmax/Kd) in striatum. The magnitude of ND-induced changes in striatal [C-11]raclopride binding were significantly larger in controls (21 + 13% change from baseline) than in cocaine abusers (9 {+-} 13 %) (ANOVA p < 0.005). In cocaine abusers, but not in controls, MP also decreased Bmax/Kd values in thalamus (29 {+-} 35 %) (ANOVA p < 0.005). There were no differences in plasma MP concentration between the groups. In striatum MP-induced changes in Bmax/Kd were significantly correlated with MP-induced changes in self reports of restlessness (r = 0.49, df 42, p < 0.002). In thalamus MP-induced changes in Bmax/Kd were significantly correlated with ND-induced changes in self reports of cocaine craving (r = 0.57, df 42, p < 0.0001). These results are compatible with a decrease in striatal DA brain function in cocaine abusers. They also suggest a participation of thalamic DA pathways in cocaine addiction.

  3. The role of thalamic population synchrony in the emergence of cortical feature selectivity.

    Directory of Open Access Journals (Sweden)

    Sean T Kelly

    2014-01-01

    Full Text Available In a wide range of studies, the emergence of orientation selectivity in primary visual cortex has been attributed to a complex interaction between feed-forward thalamic input and inhibitory mechanisms at the level of cortex. Although it is well known that layer 4 cortical neurons are highly sensitive to the timing of thalamic inputs, the role of the stimulus-driven timing of thalamic inputs in cortical orientation selectivity is not well understood. Here we show that the synchronization of thalamic firing contributes directly to the orientation tuned responses of primary visual cortex in a way that optimizes the stimulus information per cortical spike. From the recorded responses of geniculate X-cells in the anesthetized cat, we synthesized thalamic sub-populations that would likely serve as the synaptic input to a common layer 4 cortical neuron based on anatomical constraints. We used this synchronized input as the driving input to an integrate-and-fire model of cortical responses and demonstrated that the tuning properties match closely to those measured in primary visual cortex. By modulating the overall level of synchronization at the preferred orientation, we show that efficiency of information transmission in the cortex is maximized for levels of synchronization which match those reported in thalamic recordings in response to naturalistic stimuli, a property which is relatively invariant to the orientation tuning width. These findings indicate evidence for a more prominent role of the feed-forward thalamic input in cortical feature selectivity based on thalamic synchronization.

  4. Developmental Alterations of Frontal-Striatal-Thalamic Connectivity in Obsessive-Compulsive Disorder

    Science.gov (United States)

    Fitzgerald, Kate Dimond; Welsh, Robert C.; Stern, Emily R.; Angstadt, Mike; Hanna, Gregory L.; Abelson, James L.; Taylor, Stephan F.

    2011-01-01

    Objective: Pediatric obsessive-compulsive disorder is characterized by abnormalities of frontal-striatal-thalamic circuitry that appear near illness onset and persist over its course. Distinct frontal-striatal-thalamic loops through cortical centers for cognitive control (anterior cingulate cortex) and emotion processing (ventral medial frontal…

  5. Cocaine dependence and thalamic functional connectivity: a multivariate pattern analysis.

    Science.gov (United States)

    Zhang, Sheng; Hu, Sien; Sinha, Rajita; Potenza, Marc N; Malison, Robert T; Li, Chiang-Shan R

    2016-01-01

    Cocaine dependence is associated with deficits in cognitive control. Previous studies demonstrated that chronic cocaine use affects the activity and functional connectivity of the thalamus, a subcortical structure critical for cognitive functioning. However, the thalamus contains nuclei heterogeneous in functions, and it is not known how thalamic subregions contribute to cognitive dysfunctions in cocaine dependence. To address this issue, we used multivariate pattern analysis (MVPA) to examine how functional connectivity of the thalamus distinguishes 100 cocaine-dependent participants (CD) from 100 demographically matched healthy control individuals (HC). We characterized six task-related networks with independent component analysis of fMRI data of a stop signal task and employed MVPA to distinguish CD from HC on the basis of voxel-wise thalamic connectivity to the six independent components. In an unbiased model of distinct training and testing data, the analysis correctly classified 72% of subjects with leave-one-out cross-validation (p brain regions with similar voxel counts (p cocaine dependence. PMID:27556009

  6. Thalamic shape abnormalities in antipsychotic naïve schizophrenia

    Directory of Open Access Journals (Sweden)

    Vijay Danivas

    2013-01-01

    Full Text Available Background: Neurodevelopmental hypothesis of schizophrenia states abnormal pruning as one of the pathogenetic mechanism in schizophrenia. Though thalamic volume abnormalities have been documented, the shape differences of thalamus in antipsychotic-free schizophrenia in comparison with age- and sex-matched healthy volunteers need validation. Materials and Methods: We examined antipsychotic naïve schizophrenia patients ( n=60 and age- and sex-matched healthy volunteers ( n=44. The thalamic shape abnormalities were analyzed from their coded structural magnetic resonance imaging (MRI data using three-dimensional automated image analysis software, FMRIB′s (Oxford Center for the functional MRI of the brain tools-FIRST (FMRIB′s Integrated Registration and Segmentation Tool by creating deformable mesh model. Correlation with the psychopathology scores was carried out using F-statistics. Results: Patients with schizophrenia showed significant inward deformations in the regions corresponding to anterior, ventromedial, mediodorsal, and pulvinar nuclei. There was a direct correlation between negative syndrome score and the deformation in the right mediodorsal and right pulvinar nuclei. Conclusion: The inward deformations of thalamus in antipsychotic naive schizophrenia patients correspond to those nuclei which have reciprocal connections with frontal, superior temporal, and anterior cingulate regions and support the neurodevelopmental hypothesis of schizophrenia.

  7. Shaping 3-D boxes

    DEFF Research Database (Denmark)

    Stenholt, Rasmus; Madsen, Claus B.

    2011-01-01

    Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data...

  8. From Parkinsonian thalamic activity to restoring thalamic relay using deep brain stimulation: new insights from computational modeling

    Science.gov (United States)

    Meijer, H. G. E.; Krupa, M.; Cagnan, H.; Lourens, M. A. J.; Heida, T.; Martens, H. C. F.; Bour, L. J.; van Gils, S. A.

    2011-10-01

    We present a computational model of a thalamocortical relay neuron for exploring basal ganglia thalamocortical loop behavior in relation to Parkinson's disease and deep brain stimulation (DBS). Previous microelectrode, single-unit recording studies demonstrated that oscillatory interaction within and between basal ganglia nuclei is very often accompanied by synchronization at Parkinsonian rest tremor frequencies (3-10 Hz). These oscillations have a profound influence on thalamic projections and impair the thalamic relaying of cortical input by generating rebound action potentials. Our model describes convergent inhibitory input received from basal ganglia by the thalamocortical cells based on characteristics of normal activity, and/or low-frequency oscillations (activity associated with Parkinson's disease). In addition to simulated input, we also used microelectrode recordings as inputs for the model. In the resting state, and without additional sensorimotor input, pathological rebound activity is generated for even mild Parkinsonian input. We have found a specific stimulation window of amplitudes and frequencies for periodic input, which corresponds to high-frequency DBS, and which also suppresses rebound activity for mild and even more prominent Parkinsonian input. When low-frequency pathological rebound activity disables the thalamocortical cell's ability to relay excitatory cortical input, a stimulation signal with parameter settings corresponding to our stimulation window can restore the thalamocortical cell's relay functionality.

  9. Dopamine, Affordance and Active Inference

    OpenAIRE

    Friston, Karl J.; Tamara Shiner; Thomas FitzGerald; Galea, Joseph M.; Rick Adams; Harriet Brown; Dolan, Raymond J.; Rosalyn Moran; Klaas Enno Stephan; Sven Bestmann

    2012-01-01

    The role of dopamine in behaviour and decision-making is often cast in terms of reinforcement learning and optimal decision theory. Here, we present an alternative view that frames the physiology of dopamine in terms of Bayes-optimal behaviour. In this account, dopamine controls the precision or salience of (external or internal) cues that engender action. In other words, dopamine balances bottom-up sensory information and top-down prior beliefs when making hierarchical inferences (prediction...

  10. The deafferented reticular thalamic nucleus generates spindle rhythmicity.

    Science.gov (United States)

    Steriade, M; Domich, L; Oakson, G; Deschênes, M

    1987-01-01

    The hypothesis that nucleus reticularis thalami (RE) is the generator of spindle rhythmicity during electroencephalogram (EEG) synchronization was tested in acutely prepared cats. Unit discharges and focal waves were extracellularly recorded in the rostral pole of RE nucleus, which was completely disconnected by transections from all other thalamic nuclei. In some experiments, additional transections through corona radiata created a triangular island in which the rostral RE pole survived with the caudate nucleus, putamen, basal forebrain nuclei, prepyriform area, and the adjacent cortex. Similar results were obtained in two types of experiments: brain stem-transected preparations that exhibited spontaneous spindle sequences, and animals under ketamine anesthesia in which transient spindling was repeatedly precipitated during recording by very low doses of a short-acting barbiturate. Both spindle-related rhythms (7- to 16-Hz waves grouped in sequences that recur with a rhythm of 0.1-0.3 Hz) are seen in focal recordings of the deafferented RE nucleus. The presence of spindling rhythmicity in the disconnected RE nucleus contrasts with total absence of spindles in cortical EEG leads and in thalamic recordings behind the transection. Oscillations within the same frequency range as that of spontaneous spindles can be evoked in the deafferented RE nucleus by subcortical white matter stimulation. In deafferented RE cells, the burst structure consists of an initially biphasic acceleration-deceleration pattern, eventually leading to a long-lasting tonic tail. Quantitative group data show that the burst parameters of disconnected RE cells are very similar to those of RE neurons with intact connections. In the deafferented RE nucleus, spike bursts of RE neurons recur periodically (0.1-0.3 Hz) in close time-relation with simultaneously recorded focal spindle sequences. The burst occurrence of deafferented RE cells is greatly reduced after systemic administration of bicuculline

  11. Dopamine hypothesis of mania

    OpenAIRE

    Cookson, John

    2013-01-01

    s­of­the­Speakers­/­Konuşmacı­leriThe discovery of dopamine and its pathwaysDopamine (DA) was first synthesized in 1910 from 3,4-dihydroxy phenyl alanine (DOPA) by Barger and Ewens at Wellcome Laboratories in London. It is a cathecholamine and in the 1940s Blaschko in Cambridge proposed that DA was a precursor in synthesis of the cat-echolamine neurotransmitters noradrenaline (norepinephrine) and adrenaline (epinephrine). In 1957 it was shown to be present in the brain with other catecholamin...

  12. Postsynaptic receptors for cholecystokinin in the thalamic reticular nucleus: a possible modulatory system for sensory transmission

    International Nuclear Information System (INIS)

    Cholecystokinin (CCK) binding sites have been described in several areas of the brains with particularly rich localization being found in the thalamic reticular nucleus (TRN). We have studied the distribution of CCK binding sites in the TRN using a high resolution autoradiographic technique and observed that the CCK receptors were dense throughout the whole nucleus. Using Kainic acid excitotoxic lesions, it was demonstrated the CCK receptors were attached to postsynaptic elements and not afferent fibers. These results are discussed in view of the known functional role of the thalamic reticular nucleus as an inhibitory control, gating all thalamic sensory transmission systems. 21 refs

  13. 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

  14. Thalamic Volume Is Reduced in Cervical and Laryngeal Dystonias

    Science.gov (United States)

    Waugh, Jeff L.; Kuster, John K.; Levenstein, Jacob M.; Makris, Nikos; Multhaupt-Buell, Trisha J.; Sudarsky, Lewis R.; Breiter, Hans C.; Sharma, Nutan; Blood, Anne J.

    2016-01-01

    Background Dystonia, a debilitating movement disorder characterized by abnormal fixed positions and/or twisting postures, is associated with dysfunction of motor control networks. While gross brain lesions can produce secondary dystonias, advanced neuroimaging techniques have been required to identify network abnormalities in primary dystonias. Prior neuroimaging studies have provided valuable insights into the pathophysiology of dystonia, but few directly assessed the gross volume of motor control regions, and to our knowledge, none identified abnormalities common to multiple types of idiopathic focal dystonia. Methods We used two gross volumetric segmentation techniques and one voxelwise volumetric technique (voxel based morphometry, VBM) to compare regional volume between matched healthy controls and patients with idiopathic primary focal dystonia (cervical, n = 17, laryngeal, n = 7). We used (1) automated gross volume measures of eight motor control regions using the FreeSurfer analysis package; (2) blinded, anatomist-supervised manual segmentation of the whole thalamus (also gross volume); and (3) voxel based morphometry, which measures local T1-weighted signal intensity and estimates gray matter density or volume at the level of single voxels, for both whole-brain and thalamus. Results Using both automated and manual gross volumetry, we found a significant volume decrease only in the thalamus in two focal dystonias. Decreases in whole-thalamic volume were independent of head and brain size, laterality of symptoms, and duration. VBM measures did not differ between dystonia and control groups in any motor control region. Conclusions Reduced thalamic gross volume, detected in two independent analyses, suggests a common anatomical abnormality in cervical dystonia and spasmodic dysphonia. Defining the structural underpinnings of dystonia may require such complementary approaches. PMID:27171035

  15. Accuracy of MRI-guided stereotactic thalamic functional neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, G.; Magnin, M.; Morel, A.; Jeanmonod, D. [Laboratory for Functional Neurosurgery, Neurosurgical Clinic, University Hospital, Zurich (Switzerland); Sartoretti, S.; Huisman, T.; Tuncdogan, E. [Department of Neuroradiology, University Hospital, Zurich (Switzerland); Meier, D. [Institute of Biomedical Engineering and Medical Informatics, University and ETH, Zurich (Switzerland)

    1999-09-01

    Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions were performed. Their co-ordinates were corrected from adjustments based on peroperative electrophysiological data and compared to those planned. MR image distortion (maximum: 1 mm) and chemical shift of petroleum oil-filled localiser rods (2.2 mm) induced an anterior target displacement of 2.6 mm (at a field strength of 1.5 T, frequency encoding bandwidth of 187.7 kHz, on T1-weighted images). The average absolute error of the stereotactic material was 0.7 mm for anteroposterior (AP), 0.5 mm for mediolateral (ML) and 0.8 mm for dorsoventral (DV) co-ordinates (maximal absolute errors: 1.6 mm, 2.2 mm and 1.7 mm, respectively; mean euclidean error: 1 mm). Three-dimensional MRI reconstructions showed an average absolute error of 0.8 mm, 0.9 mm and 1.9 mm in AP, ML and DV co-ordinates, respectively (maximal absolute errors: 2.4 mm, 2.7 mm and 5.7 mm, respectively; mean euclidean error: 2.3 mm). MRI distortion and chemical-shift errors must be determined by a phantom study and then compensated for. The most likely explanation for an average absolute error of 1.9 mm in the DV plane is displacement of the brain under the pressure of the penetrating electrode. When this displacement is corrected for by microelectrode recordings and stimulation data, MRI offers a high degree of accuracy and reliability for thalamic stereotaxy. (orig.)

  16. The Maine Music Box

    OpenAIRE

    Lutz, Marilyn; Gallucci, Laura

    2005-01-01

    The paper describes the Maine Music Box and examines its potential as a tool for teaching and learning music. Pedagogical concepts are demonstrated using MIDI, Scorch, image and streaming video files.

  17. Voice box (image)

    Science.gov (United States)

    The larynx, or voice box, is located in the neck and performs several important functions in the body. The larynx is involved in swallowing, breathing, and voice production. Sound is produced when the air which ...

  18. Dopamine and anorexia nervosa.

    Science.gov (United States)

    Södersten, P; Bergh, C; Leon, M; Zandian, M

    2016-01-01

    We have suggested that reduced food intake increases the risk for anorexia nervosa by engaging mesolimbic dopamine neurons, thereby initially rewarding dieting. Recent fMRI studies have confirmed that dopamine neurons are activated in anorexia nervosa, but it is not clear whether this response is due to the disorder or to its resulting nutritional deficit. When the body senses the shortage of nutrients, it rapidly shifts behavior toward foraging for food as a normal physiological response and the mesolimbic dopamine neurons may be involved in that process. On the other hand, the altered dopamine status of anorexics has been suggested to result from a brain abnormality that underlies their complex emotional disorder. We suggest that the outcomes of the treatments that emerge from that perspective remain poor because they target the mental symptoms that are actually the consequences of the food deprivation that accompanies anorexia. On the other hand, a method that normalizes the disordered eating behavior of anorexics results in much better physiological, behavioral, and emotional outcomes. PMID:26608248

  19. Endoscopic considerations treating hydrocephalus caused by basal ganglia and large thalamic tumors

    Directory of Open Access Journals (Sweden)

    Jonathan Roth

    2015-01-01

    Conclusions: Endoscopic surgery may potentially play a significant role in the initial management of patients with large basal ganglia and large thalamic tumors causing obstructive hydrocephalus. Technical nuances and individualized goals are crucial for optimal outcomes.

  20. Firing properties of dopamine neurons in freely moving dopamine-deficient mice: Effects of dopamine receptor activation and anesthesia

    OpenAIRE

    Robinson, Siobhan; Smith, David M.; Mizumori, Sheri J. Y.; Palmiter, Richard D

    2004-01-01

    To examine the regulation of midbrain dopamine neurons, recordings were obtained from single neurons of freely moving, genetically engineered dopamine-deficient (DD) mice. DD mice were tested without dopamine signaling (basal state) and with endogenous dopamine signaling (after L-dopa administration). In the basal state, when dopamine concentration in DD mice is

  1. Usefulness of gamma knife pituitary surgery to control thalamic pain after treatment of thalamic malignant lymphoma and report of pathology of gamma knife lesions

    Directory of Open Access Journals (Sweden)

    Utsuki Satoshi

    2009-01-01

    Full Text Available Here, we describe the first reported autopsy findings following gamma knife surgery for thalamic pain. A 62-year-old man presented with thalamic pain after treatment for thalamic malignant lymphoma. He was treated with narcotic drugs, but his pain was uncontrollable. Treatment using gamma knife surgery on the pituitary gland using a maximum dose of 180 Gy, led to the control of his intractable pain with lower doses of drugs. His death was pain-free and was caused by a recurrence of the tumor, six months after gamma knife surgery. An autopsy was performed and necrosis was present in the area of the pituitary gland where it borders the pituitary stalk. Half of the adenohypophysis was not necrotic, and necrosis was not found in the pituitary stalk.

  2. Thalamic functional connectivity predicts seizure laterality in individual TLE patients: Application of a biomarker development strategy

    OpenAIRE

    Barron, Daniel S.; Fox, Peter T.; Heath Pardoe; Jack Lancaster; Price, Larry R.; Karen Blackmon; Kristen Berry; Cavazos, Jose E.; Ruben Kuzniecky; Orrin Devinsky; Thomas Thesen

    2014-01-01

    Noninvasive markers of brain function could yield biomarkers in many neurological disorders. Disease models constrained by coordinate-based meta-analysis are likely to increase this yield. Here, we evaluate a thalamic model of temporal lobe epilepsy that we proposed in a coordinate-based meta-analysis and extended in a diffusion tractography study of an independent patient population. Specifically, we evaluated whether thalamic functional connectivity (resting-state fMRI-BOLD) with temporal l...

  3. Amphetamine Paradoxically Augments Exocytotic Dopamine Release and Phasic Dopamine Signals

    OpenAIRE

    Daberkow, DP; Brown, HD; Bunner, KD; Kraniotis, SA; Doellman, MA; Ragozzino, ME; Garris, PA; Roitman, MF

    2013-01-01

    Drugs of abuse hijack brain reward circuitry during the addiction process by augmenting action potential-dependent phasic dopamine release events associated with learning and goal-directed behavior. One prominent exception to this notion would appear to be amphetamine (AMPH) and related analogs, which are proposed instead to disrupt normal patterns of dopamine neurotransmission by depleting vesicular stores and promoting non-exocytotic dopamine efflux via reverse transport. This mechanism of ...

  4. The BOXES Methodology Black Box Dynamic Control

    CERN Document Server

    Russell, David W

    2012-01-01

    Robust control mechanisms customarily require knowledge of the system’s describing equations which may be of the high order differential type.  In order to produce these equations, mathematical models can often be derived and correlated with measured dynamic behavior.  There are two flaws in this approach one is the level of inexactness introduced by linearizations and the other when no model is apparent.  Several years ago a new genre of control systems came to light that are much less dependent on differential models such as fuzzy logic and genetic algorithms. Both of these soft computing solutions require quite considerable a priori system knowledge to create a control scheme and sometimes complicated training program before they can be implemented in a real world dynamic system. Michie and Chambers’ BOXES methodology created a black box system that was designed to control a mechanically unstable system with very little a priori system knowledge, linearization or approximation.  All the method need...

  5. Opto-Box

    CERN Document Server

    Bertsche, David; The ATLAS collaboration; Welch, Steven; Smith, Dale Shane; Che, Siinn; Gan, K.K.; Boyd, George Russell Jr

    2015-01-01

    The opto-box is a custom mini-crate for housing optical modules, which process and transfer optoelectronic data. The system tightly integrates electrical, mechanical, and thermal functionality into a small package of size 35x10x8 cm^3. Special attention was given to ensure proper shielding, grounding, cooling, high reliability, and environmental tolerance. The custom modules, which incorporate Application Specific Integrated Circuits (ASICs), were developed through a cycle of rigorous testing and redesign. In total, fourteen opto-boxes have been installed and loaded with modules on the ATLAS detector. They are currently in operation as part of the LHC run 2 data read-out chain.

  6. Radioiodinated ligands for dopamine receptors

    International Nuclear Information System (INIS)

    The dopamine receptor system is important for normal brain function; it is also the apparent action site for various neuroleptic drugs for the treatment of schizophrenia and other metal disorders. In the past few years radioiodinated ligands for single photon emission tomography (SPECT) have been successfully developed and tested in humans: [123I]TISCH for D1 dopamine receptors; [123I]IBZM, epidepride, IBF and FIDA2, four iodobenzamide derivatives, for D2/D3 dopamine receptors. In addition, [123I]β-CIT (RTI-55) and IPT, cocaine derivatives, for the dopamine reuptake site are potentially useful for diagnosis of loss of dopamine neurons. The first iodinated ligand, (R)trans-7-OH-PIPAT, for D3 dopamine receptors, was synthesized and characterized with cloned cell lines (Spodoptera frugiperda, Sf9) expressing the D2 and D3 dopamine receptors and with rat basal forebrain membrane preparations. Most of the known iodobenzamides displayed similar potency in binding to both D2 and D3 dopamine receptors expressed in the cell lines. Initial studies appear to suggest that by fine tuning the structures it may be possible to develop agents specific for D2 and D3 dopamine receptors. It is important to investigate D2/D3 selectivity for this series of potent ligands

  7. Sleep and Cognitive Abnormalities in Acute Minor Thalamic Infarction.

    Science.gov (United States)

    Wu, Wei; Cui, Linyang; Fu, Ying; Tian, Qianqian; Liu, Lei; Zhang, Xuan; Du, Ning; Chen, Ying; Qiu, Zhijun; Song, Yijun; Shi, Fu-Dong; Xue, Rong

    2016-08-01

    In order to characterize sleep and the cognitive patterns in patients with acute minor thalamic infarction (AMTI), we enrolled 27 patients with AMTI and 12 matched healthy individuals. Questionnaires about sleep and cognition as well as polysomnography (PSG) were performed on days 14 and 90 post-stroke. Compared to healthy controls, in patients with AMTI, hyposomnia was more prevalent; sleep architecture was disrupted as indicated by decreased sleep efficiency, increased sleep latency, and decreased non-rapid eye movement sleep stages 2 and 3; more sleep-related breathing disorders occurred; and cognitive functions were worse, especially memory. While sleep apnea and long-delay memory recovered to a large extent in the patients, other sleep and cognitive function deficit often persisted. Patients with AMTI are at an increased risk for hyposomnia, sleep structure disturbance, sleep apnea, and memory deficits. Although these abnormalities improved over time, the slow and incomplete improvement suggest that early management should be considered in these patients. PMID:27237578

  8. 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.

  9. Teaching with Box Tops.

    Science.gov (United States)

    Raiser, Lynne; D'Zamko, Mary Elizabeth

    1984-01-01

    Using environmental materials (such as the phone book and placemats from fast food restaurants) can be a motivating way to teach learning disabled students skills and concepts, as shown in an approach to reading, math, science and nutrition, and social studies instruction using a JELL-O brand gelatin box. (CL)

  10. Hydrophobic, Porous Battery Boxes

    Science.gov (United States)

    Bragg, Bobby J.; Casey, John E., Jr.

    1995-01-01

    Boxes made of porous, hydrophobic polymers developed to contain aqueous potassium hydroxide electrolyte solutions of zinc/air batteries while allowing air to diffuse in as needed for operation. Used on other types of batteries for in-cabin use in which electrolytes aqueous and from which gases generated during operation must be vented without allowing electrolytes to leak out.

  11. Glove box posting system

    International Nuclear Information System (INIS)

    A system for posting objects into closed containers, such as glove boxes, is described in which the bag used, preferably made of plastic, does not have to be fitted and sealed by the operator during each posting operation. (U.K.)

  12. Cereal Box Totems.

    Science.gov (United States)

    Jones, AnnMarie

    2002-01-01

    Presents a multicultural project used with fourth-grade students in which they created a three-dimensional totem pole using leftover cereal boxes. Discusses in detail how to create the totem pole. Explains that students learned about Northwest American Indians in class. (CMK)

  13. PHOTOCHEMICAL BOX MODEL (PBM)

    Science.gov (United States)

    This magnetic tape contains the FORTRAN source code, sample input data, and sample output data for the Photochemical Box Model (PBM). The PBM is a simple stationary single-cell model with a variable height lid designed to provide volume-integrated hour averages of O3 and other ph...

  14. Methamphetamine Increases Locomotion and Dopamine Transporter Activity in Dopamine D5 Receptor-Deficient Mice

    OpenAIRE

    Hayashizaki, Seiji; Hirai, Shinobu; Ito, Yumi; Honda, Yoshiko; Arime, Yosefu; Sora, Ichiro; Okado, Haruo; Kodama, Tohru; Takada, Masahiko

    2013-01-01

    Dopamine regulates the psychomotor stimulant activities of amphetamine-like substances in the brain. The effects of dopamine are mediated through five known dopamine receptor subtypes in mammals. The functional relevance of D5 dopamine receptors in the central nervous system is not well understood. To determine the functional relevance of D5 dopamine receptors, we created D5 dopamine receptor-deficient mice and then used these mice to assess the roles of D5 dopamine receptors in the behaviora...

  15. Reduced thalamic volume in preterm infants is associated with abnormal white matter metabolism independent of injury

    Energy Technology Data Exchange (ETDEWEB)

    Wisnowski, Jessica L. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); University of Southern California, Brain and Creativity Institute, Los Angeles, CA (United States); Ceschin, Rafael C. [University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); University of Pittsburgh, Department of Biomedical Informatics, Pittsburgh, PA (United States); Choi, So Young [University of Southern California, Brain and Creativity Institute, Los Angeles, CA (United States); Schmithorst, Vincent J. [University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); Painter, Michael J. [University of Pittsburgh, Department of Pediatrics, Division of Neurology, Childrens Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); Nelson, Marvin D. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Blueml, Stefan [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Rudi Schulte Research Institute, Santa Barbara, CA (United States); Panigrahy, Ashok [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States)

    2015-05-01

    Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury. Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23-36 weeks) who underwent MR examinations under clinical indications were included in this study. Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and among the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older. These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation. (orig.)

  16. Reduced thalamic volume in preterm infants is associated with abnormal white matter metabolism independent of injury

    International Nuclear Information System (INIS)

    Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury. Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23-36 weeks) who underwent MR examinations under clinical indications were included in this study. Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and among the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older. These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation. (orig.)

  17. Decommissioning a small glove box

    International Nuclear Information System (INIS)

    An account is given of dismantling a fuel fabrication glove box using simple tooling. The fissile content of the box was first measured by several non-destructive techniques. After cleaning, the box was dismantled using hand tools and finally packed for disposal. A record of operator radiation doses, the time taken for each stage of the operation and packing information is given. (author)

  18. Opto-Box

    CERN Document Server

    Bertsche, David; The ATLAS collaboration

    2015-01-01

    The opto-box is a custom mini-crate for housing optical modules, which process and transfer optoelectronic data. Many novel solutions were developed for the custom design and manufacturing. The system tightly integrates electrical, mechanical, and thermal functionality into a small package of size 35x10x8 cm$^{3}$. Special attention was given to ensure proper shielding, grounding, cooling, high reliability, and environmental tolerance. The custom modules, which incorporate Application Specific Integrated Circuits (ASICs), were developed through a cycle of rigorous testing and redesign. In total, fourteen opto-boxes have been installed and loaded with modules on the ATLAS detector. They are currently in operation as part of the LHC run 2 data read-out chain.

  19. The Box Method

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    The velocity level in a room ventilated by jet ventilation is strongly influenced by the supply conditions. The momentum flow in the supply jets controls the air movement in the room and, therefore, it is very important that the inlet conditions and the numerical method can generate a satisfactor...... description of this momentum flow. The Box Method is a practical method for the description of an Air Terminal Device which will save grid points and ensure the right level of the momentum flow....

  20. Learning with box kernels.

    Science.gov (United States)

    Melacci, Stefano; Gori, Marco

    2013-11-01

    Supervised examples and prior knowledge on regions of the input space have been profitably integrated in kernel machines to improve the performance of classifiers in different real-world contexts. The proposed solutions, which rely on the unified supervision of points and sets, have been mostly based on specific optimization schemes in which, as usual, the kernel function operates on points only. In this paper, arguments from variational calculus are used to support the choice of a special class of kernels, referred to as box kernels, which emerges directly from the choice of the kernel function associated with a regularization operator. It is proven that there is no need to search for kernels to incorporate the structure deriving from the supervision of regions of the input space, because the optimal kernel arises as a consequence of the chosen regularization operator. Although most of the given results hold for sets, we focus attention on boxes, whose labeling is associated with their propositional description. Based on different assumptions, some representer theorems are given that dictate the structure of the solution in terms of box kernel expansion. Successful results are given for problems of medical diagnosis, image, and text categorization. PMID:24051728

  1. Autobiogutobiographical amnesia and cognltive disorder resulgting from bilateral severe thalamic infarction Two cases reports

    Institute of Scientific and Technical Information of China (English)

    Ytt Kai; Yu Feng Qi; Lei Zheng Lin; Zhang Jun

    2000-01-01

    Objective To report two cases of patients with bilateral severe thalamic infarction.which showed autobiographical amnesia and cognitive disorders and to shed light on the mechanisms underlying thc retrograde amenesia. Method The two cases were studied clinically, CT and MRI were performed also, Language and neuropsychological tests were evaluated. Results Two patients with a chronic amnesia and cogntive disorders resulting from bilateral paramedian thalamic infarction showed a pattern of retrograde amnesia personally relevent autobiographical memory were prefoundly impaired .Whereas about the famous people and public events were relatively impaired. The patients almost had no thalamic aphasia.The events the one described showed spontaneously confabulated. Conclusion We think a probable explanation that the disorders at the thematic retrieval fiomwork ievel of memory and the information reconstruction due to a disconnetion of frontal and medial temperal memory systems.

  2. Molecular anatomy of the thalamic complex and the underlying transcription factors.

    Science.gov (United States)

    Nagalski, Andrzej; Puelles, Luis; Dabrowski, Michal; Wegierski, Tomasz; Kuznicki, Jacek; Wisniewska, Marta B

    2016-06-01

    Thalamocortical loops have been implicated in the control of higher-order cognitive functions, but advances in our understanding of the molecular underpinnings of neocortical organization have not been accompanied by similar analyses in the thalamus. Using expression-based correlation maps and the manual mapping of mouse and human datasets available in the Allen Brain Atlas, we identified a few individual regions and several sets of molecularly related nuclei that partially overlap with the classic grouping that is based on topographical localization and thalamocortical connections. These new molecular divisions of the adult thalamic complex are defined by the combinatorial expression of Tcf7l2, Lef1, Gbx2, Prox1, Pou4f1, Esrrg, and Six3 transcription factor genes. Further in silico and experimental analyses provided the evidence that TCF7L2 might be a pan-thalamic specifier. These results provide substantial insights into the "molecular logic" that underlies organization of the thalamic complex. PMID:25963709

  3. Dopamine Oxidation and Autophagy

    Directory of Open Access Journals (Sweden)

    Patricia Muñoz

    2012-01-01

    Full Text Available The molecular mechanisms involved in the neurodegenerative process of Parkinson's disease remain unclear. Currently, there is a general agreement that mitochondrial dysfunction, α-synuclein aggregation, oxidative stress, neuroinflammation, and impaired protein degradation are involved in the neurodegeneration of dopaminergic neurons containing neuromelanin in Parkinson's disease. Aminochrome has been proposed to play an essential role in the degeneration of dopaminergic neurons containing neuromelanin by inducing mitochondrial dysfunction, oxidative stress, the formation of neurotoxic α-synuclein protofibrils, and impaired protein degradation. Here, we discuss the relationship between the oxidation of dopamine to aminochrome, the precursor of neuromelanin, autophagy dysfunction in dopaminergic neurons containing neuromelanin, and the role of dopamine oxidation to aminochrome in autophagy dysfunction in dopaminergic neurons. Aminochrome induces the following: (i the formation of α-synuclein protofibrils that inactivate chaperone-mediated autophagy; (ii the formation of adducts with α- and β-tubulin, which induce the aggregation of the microtubules required for the fusion of autophagy vacuoles and lysosomes.

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

    International Nuclear Information System (INIS)

    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

  5. 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

  6. Apathy, cognitive dysfunction and impaired social cognition in a patient with bilateral thalamic infarction.

    Science.gov (United States)

    Ioannidis, Anestis E; Kimiskidis, Vasilios K; Loukopoulou, Eleni; Geroukis, Triantafyllos; Vlaikidis, Nikolaos; Kosmidis, Mary H

    2013-01-01

    We describe the case of a patient with bilateral thalamic lesions due to brain infarcts in the paramedian thalamic artery territories. The patient demonstrated symptoms of apathy (e.g., loss of initiative and interest in others, poor motivation, flattened affect). Neuropsychological assessment 3 and 5 years post-infarct revealed severe deficits in verbal and non-verbal immediate and delayed memory, attention, and executive functioning, with minimal improvement over time. Also, he demonstrated difficulties in social cognition (i.e., perception of facial expressions of others and of sarcasm). These findings are discussed and interpreted in light of current theories regarding the neurobiological substrate of apathy. PMID:22816313

  7. Dopamine, reward learning, and active inference

    OpenAIRE

    Thomas Fitzgerald; Ray Dolan

    2015-01-01

    Temporal difference learning models propose phasic dopamine signalling encodes reward prediction errors that drive learning. This is supported by studies where optogenetic stimulation of dopamine neurons can stand in lieu of actual reward. Nevertheless, a large body of data also shows that dopamine is not necessary for learning, and that dopamine depletion primarily affects task performance. We offer a resolution to this paradox based on an hypothesis that dopamine encodes the precision of b...

  8. Midbrain dopamine D2/3 receptor binding in schizophrenia.

    Science.gov (United States)

    Tuppurainen, Heli; Kuikka, Jyrki T; Laakso, Mikko P; Viinamäki, Heimo; Husso, Minna; Tiihonen, Jari

    2006-09-01

    Several studies suggest that dysregulation of dopaminergic transmission in the midbrain and thalamus may contribute to the symptomatology of schizophrenia. The objective of this study was to examine the putative alteration of dopamine D(2/3 )receptor densities in the thalamus and midbrain of drug-naïve schizophrenic patients. We used the high-affinity single-photon emission tomography ligand [(123)I]epidepride for imaging D(2/3 )receptor binding sites in six neuroleptic-naïve schizophrenic patients, and seven healthy controls. Schizophrenic symptoms were evaluated by the Positive and Negative Syndrome Scale. Significantly lower D(2/3 )values were observed in the midbrain of patients with schizophrenia compared to controls (P = 0.02). No statistically significant difference was observed in the thalamus between two groups. Negative correlations were found between thalamic D(2/3 )receptor binding and general psychopathological schizophrenic symptoms (r from -0.78 to -0.92). These observations implicate altered dopaminergic activity in the midbrain of schizophrenic patients. PMID:16783502

  9. How Dopamine Transporter Interacts with Dopamine: Insights from Molecular Modeling and Simulation

    OpenAIRE

    Huang, Xiaoqin; Zhan, Chang-Guo

    2007-01-01

    By performing homology modeling, molecular docking, and molecular dynamics simulations, we have developed three-dimensional (3D) structural models of both dopamine transporter and dopamine transporter-dopamine complex in the environment of lipid bilayer and solvent water. According to the simulated structure of dopamine transporter-dopamine complex, dopamine was orientated in a hydrophobic pocket at the midpoint of the membrane. The modeled 3D structures provide some detailed structural and m...

  10. Dopamine signaling: target in glioblastoma

    Czech Academy of Sciences Publication Activity Database

    Bartek, Jiří; Hodný, Zdeněk

    2014-01-01

    Roč. 5, č. 5 (2014), 1116-1117. ISSN 1949-2553 Institutional support: RVO:68378050 Keywords : Dopamine signaling * glioblastoma * MAPK Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.359, year: 2014

  11. Projection optics box

    Science.gov (United States)

    Hale, Layton C.; Malsbury, Terry; Hudyma, Russell M.; Parker, John M.

    2000-01-01

    A projection optics box or assembly for use in an optical assembly, such as in an extreme ultraviolet lithography (EUVL) system using 10-14 nm soft x-ray photons. The projection optics box utilizes a plurality of highly reflective optics or mirrors, each mounted on a precision actuator, and which reflects an optical image, such as from a mask, in the EUVL system onto a point of use, such as a target or silicon wafer, the mask, for example, receiving an optical signal from a source assembly, such as a developed from laser system, via a series of highly reflective mirrors of the EUVL system. The plurality of highly reflective optics or mirrors are mounted in a housing assembly comprised of a series of bulkheads having wall members secured together to form a unit construction of maximum rigidity. Due to the precision actuators, the mirrors must be positioned precisely and remotely in tip, tilt, and piston (three degrees of freedom), while also providing exact constraint.

  12. Interval timing, dopamine, and motivation

    OpenAIRE

    Balcı, Fuat

    2014-01-01

    The dopamine clock hypothesis suggests that the dopamine level determines the speed of the hypothetical internal clock. However, dopaminergic function has also been implicated for motivation and thus the effect of dopaminergic manipulations on timing behavior might also be independently mediated by altered motivational state. Studies that investigated the effect of motivational manipulations on peak responding are reviewed in this paper. The majority of these studies show that a higher reward...

  13. Neuroanatomy of a neurobehavioral disturbance in the left anterior thalamic infarction

    OpenAIRE

    Nishio, Yoshiyuki; Hashimoto, Mamoru; Ishii, Kazunari; Mori, Etsuro

    2011-01-01

    Background and purpose Cognitive and behavioural symptoms represent primary clinical manifestations of anterior thalamic infarcts (ATIs) in the tuberothalamic artery territory. The aim of the study is to understand the pathomechanism of cognitive and behavioural disturbances in left ATI (LATI). Methods 6 patients with isolated LATIs were investigated using neuropsychological assessments, MRI stereotactic lesion localisation and positron emission tomography. Results The patients were character...

  14. MRI volumetry shows increased anterior thalamic volumes in patients with absence seizures.

    Science.gov (United States)

    Betting, Luiz Eduardo; Mory, Susana Barreto; Lopes-Cendes, Iscia; Li, Li Min; Guerreiro, Marilisa M; Guerreiro, Carlos A M; Cendes, Fernando

    2006-05-01

    The interaction between thalamus and cortex appears to be critical to the pathophysiology of idiopathic generalized epilepsies (IGEs). The objective of this study was to investigate thalamic volumes of a group of patients with IGEs using high-resolution MRI. Thalamic segmentation was performed by the same rater, who was unaware of the diagnosis. Thalamic volumes were divided into anterior half and posterior half. One hundred forty-seven patients were scanned (71 with juvenile myoclonic epilepsy, 49 with generalized tonic-clonic seizures only, and 27 with absence epilepsy). Subgroup analyses with corrections for multiple comparisons showed that, when compared with those of controls, anterior thalamic volumes were increased in patients with absence epilepsy and juvenile myoclonic epilepsy with absence seizures, but not in patients with generalized tonic-clonic seizures only and juvenile myoclonic epilepsy without absence seizures. Our results demonstrated that the anterior thalamus is structurally different in patients with IGEs and absence seizures as compared with patients with IGEs without absence seizures. PMID:16530016

  15. A stereological study of the mediodorsal thalamic nucleus in Down syndrome

    DEFF Research Database (Denmark)

    Karlsen, A S; Korbo, S; Uylings, H B M;

    2014-01-01

    The total number of neurons and glial cells in the mediodorsal thalamic (MDT) nucleus of four aged females with Down syndrome (DS; mean age 69years) was estimated and compared to six age- and sex-matched controls. The MDT nucleus was delineated on coronal sections, and cell numbers (large and small...

  16. Distinct molecular components for thalamic- and cortical-dependent plasticity in the lateral amygdala

    Directory of Open Access Journals (Sweden)

    Osvaldo eMirante

    2014-07-01

    Full Text Available N-methyl-D-aspartate receptor (NMDAR-dependent long-term depression (LTD in the lateral nucleus of the amygdala (LA is a form of synaptic plasticity thought to be a cellular substrate for the extinction of fear memory. The LA receives converging inputs from the sensory thalamus and neocortex that are weakened following fear extinction. Combining field and patch-clamp electrophysiological recordings in mice, we show that a paired-pulse low-frequency stimulation can induce a robust LTD at thalamic and cortical inputs to LA, and we identify different underlying molecular components at these pathways. We show that while LTD depends on NMDARs and activation of the protein phosphatases PP2B and PP1 at both pathways, it requires NR2B-containing NMDARs at the thalamic pathway, but NR2C/D-containing NMDARs at the cortical pathway. LTD appears to be induced postsynaptically at the thalamic input but presynaptically at the cortical input, since postsynaptic calcium chelation and NMDAR blockade prevent thalamic but not cortical LTD. These results highlight distinct molecular features of LTD in LA that may be relevant for traumatic memory and its erasure, and for pathologies such as post-traumatic stress disorder (PTSD.

  17. Mesolimbic dopamine signals the value of work.

    Science.gov (United States)

    Hamid, Arif A; Pettibone, Jeffrey R; Mabrouk, Omar S; Hetrick, Vaughn L; Schmidt, Robert; Vander Weele, Caitlin M; Kennedy, Robert T; Aragona, Brandon J; Berke, Joshua D

    2016-01-01

    Dopamine cell firing can encode errors in reward prediction, providing a learning signal to guide future behavior. Yet dopamine is also a key modulator of motivation, invigorating current behavior. Existing theories propose that fast (phasic) dopamine fluctuations support learning, whereas much slower (tonic) dopamine changes are involved in motivation. We examined dopamine release in the nucleus accumbens across multiple time scales, using complementary microdialysis and voltammetric methods during adaptive decision-making. We found that minute-by-minute dopamine levels covaried with reward rate and motivational vigor. Second-by-second dopamine release encoded an estimate of temporally discounted future reward (a value function). Changing dopamine immediately altered willingness to work and reinforced preceding action choices by encoding temporal-difference reward prediction errors. Our results indicate that dopamine conveys a single, rapidly evolving decision variable, the available reward for investment of effort, which is employed for both learning and motivational functions. PMID:26595651

  18. Dopamine, affordance and active inference.

    Directory of Open Access Journals (Sweden)

    Karl J Friston

    2012-01-01

    Full Text Available The role of dopamine in behaviour and decision-making is often cast in terms of reinforcement learning and optimal decision theory. Here, we present an alternative view that frames the physiology of dopamine in terms of Bayes-optimal behaviour. In this account, dopamine controls the precision or salience of (external or internal cues that engender action. In other words, dopamine balances bottom-up sensory information and top-down prior beliefs when making hierarchical inferences (predictions about cues that have affordance. In this paper, we focus on the consequences of changing tonic levels of dopamine firing using simulations of cued sequential movements. Crucially, the predictions driving movements are based upon a hierarchical generative model that infers the context in which movements are made. This means that we can confuse agents by changing the context (order in which cues are presented. These simulations provide a (Bayes-optimal model of contextual uncertainty and set switching that can be quantified in terms of behavioural and electrophysiological responses. Furthermore, one can simulate dopaminergic lesions (by changing the precision of prediction errors to produce pathological behaviours that are reminiscent of those seen in neurological disorders such as Parkinson's disease. We use these simulations to demonstrate how a single functional role for dopamine at the synaptic level can manifest in different ways at the behavioural level.

  19. ED-27CLINICAL CHARACTERISTICS AND LONG-TERM OUTCOME IN MOVEMENT DISORDER IN CHILDHOOD THALAMIC TUMORS

    Science.gov (United States)

    Sadighi, Zsila; Zabrowski, Jennifer; Broniscer, Alberto; Gajjar, Amar; Khan, Raja

    2014-01-01

    BACKGROUND: Clinical observations of children with thalamic tumors and secondary movement disorders (MD) suggest correlation between anatomical location and treatment modalities to severity of MD. METHODS: We conducted an IRB approved retrospective review of patients ≤ 18 years old with thalamic tumors and MD at St. Jude Children's Research Hospital from 1996-2013. Magnetic Resonance Imaging (MRI) was reviewed and thalamic nuclei involved with tumor and/or surgical site were documented. MD severity was rated with Karnofsky Performance Score (KPS); Extrapyramidal Symptom Rating Scale (ESRS), which scores 0 (absent) to 6 (extremely severe); and Clinical Global Impression of Severity for dystonia and dyskinesia (CGI-S), which scores 0 (absent) to 8 (extremely severe). RESULTS: We reviewed 83 patients with thalamic with 9 confirmed MD by neurological evaluation. Median age at tumor diagnosis was 7 years old (3 months-11 years), median age at MD onset was 7 years old (18 months-11 years). Types of MD found were postural tremor (7), ballismus (4), myoclonus (1), and athetosis (4). Median time to last follow-up was 3 years. 8 patients had onset of MD median of 1.5 months (0-4 months) time after surgical intervention. Initial median KPS was 80 (60-90) and at last follow-up was 80 (50-90). Initial median ESRS was 5 (3-8) and at last follow-up was 5 (0-5). Initial median CGI-S was 5 (3-6) and at last follow-up was 4 (0-6). Based on these severity scales, 2 patients showed no change, 1 patient worsened, 1 patient completely resolved, and 4 patients had improvement regardless of initial extent of surgery or number of nuclei involved. CONCLUSION: This retrospective analysis compares thalamic tumor anatomical locations and treatment intervention with respect to movement disorder clinical characteristics and outcomes. Extent of location and surgical intervention did not correlate to severity and will be included in final presentation.

  20. Disrupted thalamic resting-state functional connectivity in patients with minimal hepatic encephalopathy

    International Nuclear Information System (INIS)

    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

  1. Disrupted thalamic resting-state functional connectivity in patients with minimal hepatic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    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

  2. Thalamic neuron models encode stimulus information by burst-size modulation

    Directory of Open Access Journals (Sweden)

    Daniel Henry Elijah

    2015-09-01

    Full Text Available Thalamic neurons have been long assumed to fire in tonic mode during perceptive states, and in burst mode during sleep and unconsciousness. However, recent evidence suggests that bursts may also be relevant in the encoding of sensory information. Here we explore the neural code of such thalamic bursts. In order to assess whether the burst code is generic or whether it depends on the detailed properties of each bursting neuron, we analyzed two neuron models incorporating different levels of biological detail. One of the models contained no information of the biophysical processes entailed in spike generation, and described neuron activity at a phenomenological level. The second model represented the evolution of the individual ionic conductances involved in spiking and bursting, and required a large number of parameters. We analyzed the models' input selectivity using reverse correlation methods and information theory. We found that n-spike bursts from both models transmit information by modulating their spike count in response to changes to instantaneous input features, such as slope, phase, amplitude, etc. The stimulus feature that is most efficiently encoded by bursts, however, need not coincide with one of such classical features. We therefore searched for the optimal feature among all those that could be expressed as a linear transformation of the time-dependent input current. We found that bursting neurons transmitted 6 times more information about such more general features. The relevant events in the stimulus were located in a time window spanning ~100 ms before and ~20 ms after burst onset. Most importantly, the neural code employed by the simple and the biologically realistic models was largely the same, implying that the simple thalamic neuron model contains the essential ingredients that account for the computational properties of the thalamic burst code. Thus, our results suggest the n-spike burst code is a general property of

  3. Altered neurocircuitry in the dopamine transporter knockout mouse brain.

    Directory of Open Access Journals (Sweden)

    Xiaowei Zhang

    Full Text Available The plasma membrane transporters for the monoamine neurotransmitters dopamine, serotonin, and norepinephrine modulate the dynamics of these monoamine neurotransmitters. Thus, activity of these transporters has significant consequences for monoamine activity throughout the brain and for a number of neurological and psychiatric disorders. Gene knockout (KO mice that reduce or eliminate expression of each of these monoamine transporters have provided a wealth of new information about the function of these proteins at molecular, physiological and behavioral levels. In the present work we use the unique properties of magnetic resonance imaging (MRI to probe the effects of altered dopaminergic dynamics on meso-scale neuronal circuitry and overall brain morphology, since changes at these levels of organization might help to account for some of the extensive pharmacological and behavioral differences observed in dopamine transporter (DAT KO mice. Despite the smaller size of these animals, voxel-wise statistical comparison of high resolution structural MR images indicated little morphological change as a consequence of DAT KO. Likewise, proton magnetic resonance spectra recorded in the striatum indicated no significant changes in detectable metabolite concentrations between DAT KO and wild-type (WT mice. In contrast, alterations in the circuitry from the prefrontal cortex to the mesocortical limbic system, an important brain component intimately tied to function of mesolimbic/mesocortical dopamine reward pathways, were revealed by manganese-enhanced MRI (MEMRI. Analysis of co-registered MEMRI images taken over the 26 hours after introduction of Mn(2+ into the prefrontal cortex indicated that DAT KO mice have a truncated Mn(2+ distribution within this circuitry with little accumulation beyond the thalamus or contralateral to the injection site. By contrast, WT littermates exhibit Mn(2+ transport into more posterior midbrain nuclei and contralateral

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

    Directory of Open Access Journals (Sweden)

    KathrynL.Mills

    2012-01-01

    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.

  5. Glove-box filters

    International Nuclear Information System (INIS)

    Description is given of a device for simply and rapidly assembling and dissassembling the filters used inside sealed enclosures, such as glove-boxes and shielded cells equipped with nippers or manipulators, said filters being of the type comprising a cylindrical casing containing a filtering member, the upper portion of said casing being open so as to allow the gases to be cleaned to flow in, whereas the casing bottom is centrally provided with a hole extended outwardly by a threaded collar on which is screwed a connecting-sleeve to be fixed to the mouth of a gas outlet pipe. To a yoke transverse bar is welded a pin which can be likened to a bent spring-blade, one arm of which welded to said transverse bar, is rectilinear whereas its other arm is provided with a boss cooperating with a cavity made in a protrusion of said pipe, right under the mouth thereof

  6. ACSYS in a box

    CERN Document Server

    Briegel, C; Hendricks, B; King, C; Lackey, S; Neswold, R; Nicklaus, D; Patrick, J; Petrov, A; Rechenmacher, R; Schumann, C; Smedinghoff, J

    2012-01-01

    The Accelerator Control System at Fermilab has evolved to enable this relatively large control system to be encapsulated into a "box" such as a laptop. The goal was to provide a platform isolated from the "online" control system. This platform can be used internally for making major upgrades and modifications without impacting operations. It also provides a standalone environment for research and development including a turnkey control system for collaborators. Over time, the code base running on Scientific Linux has enabled all the salient features of the Fermilab's control system to be captured in an off-the-shelf laptop. The anticipated additional benefits of packaging the system include improved maintenance, reliability, documentation, and future enhancements.

  7. Cardboard Boxes: Learning Concepts Galore!

    Science.gov (United States)

    Warner, Laverne; Wilmoth, Linda

    2007-01-01

    Mrs. Keenan, a preschool teacher, observed her 3-year-old granddaughter Riley pull, tug, and stack piles of holiday boxes on the floor. She remembered that her child care director had suggested using boxes as a curriculum theme, but she hadn't given much thought about the idea until now. She said to herself, "I wonder if my children would be as…

  8. NEUROTRANSMITTERS AND IMMUNITY: 1. DOPAMINE

    Directory of Open Access Journals (Sweden)

    Lucian Hritcu

    2007-08-01

    Full Text Available Dopamine is one of the principal neurotransmitters in the central nervous system (CNC, and its neuronal pathways are involved in several key functions such as behavior (Hefco et al., 2003a,b, control of movement, endocrine regulation, immune response (Fiserova et al., 2002; Levite et al., 2001, Hritcu et al., 2006a,b,c, and cardiovascular function. Dopamine has at least five G-protein, coupled receptor subtypes, D1-D5, each arising from a different gene (Sibley et al., 1993. Traditionally, these receptors have been classified into D1-like (the D1 and D5 and D2-like (D2, D3 and D4 receptors subtypes, primarily according to their ability to stimulate or inhibit adenylate cyclase, respectively, and to their pharmacological characteristics (Seeman et al., 1993. Receptors for dopamine (particularly of D2 subclass are the primary therapeutic target in a number of neuropathological disorders including schizophrenia, Parkinson’s disease and Huntington’s chorea (Seeman et al., 1987. Neither dopamine by itself, nor dopaminergic agonists by themselves, has been shown to activate T cell function. Nevertheless, lymphocytes are most probably exposed to dopamine since the primary and secondary lymphoid organs of various mammals are markedly innervated, and contain nerve fibers which stain for tyrosine hydroxylase (Weihe et al., 1991, the enzyme responsible for dopamine synthesis. Moreover, cathecolamines and their metabolites are present in single lymphocytes and in extracts of T and B cell clones, and pharmacological inhibition of tyrosine hydroxylase reduces catecholamine levels, suggesting catecholamine synthesis by lymphocytes (Bergquist et al., 1994. The existence of putative dopamine receptors of D2, D3, D4 and D5 subtypes on immune cells has been proposed of several authors, primarily on the basis of dopaminergic ligand binding assays and specific mRNA expression as monitored by reverse transcription-PCR. Several experiments evoked the idea of a

  9. Dopamine, reward learning, and active inference

    Directory of Open Access Journals (Sweden)

    Thomas eFitzgerald

    2015-11-01

    Full Text Available Temporal difference learning models propose phasic dopamine signalling encodes reward prediction errors that drive learning. This is supported by studies where optogenetic stimulation of dopamine neurons can stand in lieu of actual reward. Nevertheless, a large body of data also shows that dopamine is not necessary for learning, and that dopamine depletion primarily affects task performance. We offer a resolution to this paradox based on an hypothesis that dopamine encodes the precision of beliefs about alternative actions, and thus controls the outcome-sensitivity of behaviour. We extend an active inference scheme for solving Markov decision processes to include learning, and show that simulated dopamine dynamics strongly resemble those actually observed during instrumental conditioning. Furthermore, simulated dopamine depletion impairs performance but spares learning, while simulated excitation of dopamine neurons drives reward learning, through aberrant inference about outcome states. Our formal approach provides a novel and parsimonious reconciliation of apparently divergent experimental findings.

  10. Genetics Home Reference: dopamine transporter deficiency syndrome

    Science.gov (United States)

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions dopamine transporter deficiency syndrome dopamine ...

  11. Students' approaches to mathematical tasks using software as a black-box, glass-box or open-box

    OpenAIRE

    Hosein, Anesa

    2009-01-01

    Three mathematical software modes are investigated in this thesis: black-box software showing no mathematical steps; glass-box software showing the intermediate mathematical steps; and open-box software showing and allowing interaction at the intermediate mathematical steps. The glass-box and open-box software modes are often recommended over the black-box software to help understanding but there is limited research comparing all three. This research investigated students' performance and the...

  12. Dopamine gates sensory representations in cortex

    OpenAIRE

    Eshel, Neir; Tian, Ju

    2014-01-01

    The prefrontal cortex (PFC) maintains information about relevant sensory stimuli, in a process thought to rely on dopamine release. In a recent paper, Jacob et al. (J Neurosci 33: 13724–13734, 2013) demonstrated one way in which dopamine might facilitate this process. The authors recorded from PFC neurons in monkeys during local application of dopamine. They found that dopamine increases the gain of sensory-evoked responses in putative pyramidal neurons in PFC, potentially by inhibiting local...

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

    OpenAIRE

    de Groote, C; 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 examined the effects of blockade of GABAB receptors in the ventromedial thalamic nucleus of rats with a unilateral 6-OHDA lesion of the substantia nigra on locomotor activity. In addition we studied the ...

  14. Dopamine agents for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Junker, Anders Ellekær; Als-Nielsen, Bodil; Gluud, Christian;

    2014-01-01

    BACKGROUND: Patients with hepatic encephalopathy may present with extrapyramidal symptoms and changes in basal ganglia. These changes are similar to those seen in patients with Parkinson's disease. Dopamine agents (such as bromocriptine and levodopa, used for patients with Parkinson's disease) have...... therefore been assessed as a potential treatment for patients with hepatic encephalopathy. OBJECTIVES: To evaluate the beneficial and harmful effects of dopamine agents versus placebo or no intervention for patients with hepatic encephalopathy. SEARCH METHODS: Trials were identified through the Cochrane...... the trials followed participants after the end of treatment. Only one trial reported adequate bias control; the remaining four trials were considered to have high risk of bias. Random-effects model meta-analyses showed that dopamine agents had no beneficial or detrimental effect on hepatic...

  15. Method of positioning channel box

    International Nuclear Information System (INIS)

    Upon measuring the dimension of a channel box by disposing ultrasonic sensors to the uppermost portion of a measuring device main body, the deviation of the channel box from the center of the device main body is detected by measuring the distance betwen the sensors at the uppermost portion of the device main body and the lower end of the channel box for four surfaces simultaneously. The direction and the distance for moving the channel box to the center of the device main body are calculated based on the results to feedback tham for the operation of a fuel exchanger, thereby positioning the channel box upon insertion to the device main body. That is, a fuel assembly loaded with the channel box is gradually brought down being suspended from a crane and the position of the channel box is recognized by the ultrasonic sensors, thereafter, the position of the center is corrected and it is brought down again and the outer dimension is measured. Accurate positioning in a short periodof time is enabled and operator's burden can be mitigated to prevent the danger of indury. (N.H.)

  16. Microclimate boxes for panel paintings

    DEFF Research Database (Denmark)

    Wadum, Jørgen

    The use of microclimate boxes to protect vulnerable panel paintings is, therefore, not a new phenomenon of the past two or three decades. Rather, it has been a concern for conservators and curators to protect these objects of art at home and in transit since the end of the nineteenth century. The...... increased number of travelling exhibitions in recent years has heightened the need to protect paintings during circulation (Thomson 1961; Mecklenburg 1991). The use and design of microclimate boxes have been evolving since 1892. These boxes may be divided into three broad groups: those using an active...

  17. Two-dimensional box plot

    OpenAIRE

    Phattrawan Tongkumchum

    2005-01-01

    In this paper we propose a two-dimensional box plot, a simple bivariate extension of the box plot and the scatter plot. This plot comprises a pair of trapeziums oriented in the direction of a fitted straight line, with symbols denoting extreme values. The choice for the fitted straight resistant line showing the relationship between the two variables is Tukey’s resistance line. The main components of the plot are an inner box containing 50% of the projection points of the observations on the ...

  18. Crossed cerebellar and uncrossed basal ganglia and thalamic diaschisis in Alzheimer's disease

    International Nuclear Information System (INIS)

    We detected crossed cerebellar as well as uncrossed basal ganglia and thalamic diaschisis in Alzheimer's disease by positron emission tomography (PET) using 18F-fluorodeoxyglucose. We studied a series of 26 consecutive, clinically diagnosed Alzheimer cases, including 6 proven by later autopsy, and compared them with 9 age-matched controls. We calculated asymmetry indices (AIs) of cerebral metabolic rate for matched left-right regions of interest (ROIs) and determined the extent of diaschisis by correlative analyses. For the Alzheimer group, we found cerebellar AIs correlated negatively, and thalamic AIs positively, with those of the cerebral hemisphere and frontal, temporal, parietal, and angular cortices, while basal ganglia AIs correlated positively with frontal cortical AIs. The only significant correlation of AIs for normal subjects was between the thalamus and cerebral hemisphere. These data indicate that PET is a sensitive technique for detecting diaschisis

  19. Thalamic abnormalities are a cardinal feature of alcohol-related brain dysfunction.

    Science.gov (United States)

    Pitel, Anne Lise; Segobin, Shailendra H; Ritz, Ludivine; Eustache, Francis; Beaunieux, Hélène

    2015-07-01

    Two brain networks are particularly affected by the harmful effect of chronic and excessive alcohol consumption: the circuit of Papez and the frontocerebellar circuit, in both of which the thalamus plays a key role. Shrinkage of the thalamus is more severe in alcoholics with Korsakoff's syndrome (KS) than in those without neurological complication (AL). In accordance with the gradient effect of thalamic abnormalities between AL and KS, the pattern of brain dysfunction in the Papez's circuit results in anterograde amnesia in KS and only mild-to-moderate episodic memory disorders in AL. On the opposite, dysfunction of the frontocerebellar circuit results in a similar pattern of working memory and executive deficits in the AL and KS. Several hypotheses, mutually compatible, can be drawn to explain that the severe thalamic shrinkage observed in KS has different consequences in the neuropsychological profile associated with the two brain networks. PMID:25108034

  20. Memory Profiles after Unilateral Paramedian Thalamic Stroke Infarction: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Antonio Carota

    2015-01-01

    Full Text Available We performed extensive neuropsychological assessment of two male patients (matched for age and educational level with similar (localization and size unilateral paramedian ischemic thalamic lesions (AB on the left and SD on the right. Both patients showed severe memory impairments as well as other cognitive deficits. In comparison to SD, AB showed severe impairment of executive functions and a more severe deficit of episodic/anterograde memory, especially in the verbal modality. The findings of this single case study suggest the possibility that the profile and severity of the executive dysfunction are determinant for the memory deficits and depend on from the side of the lesion. In addition to a material-side-specific (verbal versus visual deficit hypothesis, the differential diencephalo-prefrontal contributions in mnestic-processing, in case of paramedian thalamic stroke, might also be explained in terms of their stage-specificity (encoding versus retrieval.

  1. Autoradiographic localization of extrastriatal D2-dopamine receptors in the human brain using [125I]epidepride.

    Science.gov (United States)

    Hall, H; Farde, L; Halldin, C; Hurd, Y L; Pauli, S; Sedvall, G

    1996-06-01

    Epidepride is a benzamide with high affinity for central D2- and D3-dopamine receptors. The anatomical distribution of [125I]epidepride binding was examined by autoradiography, using postmortem human whole-hemisphere cryosections. The density of [125I]epidepride binding sites was high in caudate nucleus and putamen. [125I]epidepride also labeled receptors in extrastriatal region such as in the pallidum, some thalamic nuclei, the neocortex, and the substantia nigra. The neocortical binding was heterogeneously distributed. In most cortical regions, binding sites were located in superficial layers (I-II). However, in basal levels of the occipital cortex, [125I]epidepride binding was located in a deeper layer, probably corresponding to layer V. Competition studies indicated that most of the [125I]epidepride binding represented predominantly D2-dopamine receptors, in striatal as well as in extrastriatal regions. The presence of extrastriatal D2-dopamine receptor populations is of particular interest for research on schizophrenia and antipsychotic drug action. PMID:8723716

  2. Dynamics of Action Potential Initiation in the GABAergic Thalamic Reticular Nucleus In Vivo

    OpenAIRE

    Fabián Muñoz; Pablo Fuentealba

    2012-01-01

    Understanding the neural mechanisms of action potential generation is critical to establish the way neural circuits generate and coordinate activity. Accordingly, we investigated the dynamics of action potential initiation in the GABAergic thalamic reticular nucleus (TRN) using in vivo intracellular recordings in cats in order to preserve anatomically-intact axo-dendritic distributions and naturally-occurring spatiotemporal patterns of synaptic activity in this structure that regulates the th...

  3. Two Case Reports on Thalamic and Basal Ganglia Involvement in Children with Dengue Fever

    Science.gov (United States)

    Adhikari, Lihini; Wijesekera, Saraji; Wijayawardena, Maheshaka; Chandrasiri, Suchithra

    2016-01-01

    There have been increasing numbers of case reports of dengue infection with unusual manifestations. Such unusual manifestations including acute liver failure and encephalopathy could be manifested even in the absence of significant plasma leakage. Further, severe organ involvement including nervous system involvement indicates severe dengue infection. However, neurological manifestations of dengue fever are rare. This is the first case report of dengue infection with thalamic and basal ganglia involvement in Sri Lanka. PMID:27478661

  4. Two Case Reports on Thalamic and Basal Ganglia Involvement in Children with Dengue Fever.

    Science.gov (United States)

    Liyanage, Guwani; Adhikari, Lihini; Wijesekera, Saraji; Wijayawardena, Maheshaka; Chandrasiri, Suchithra

    2016-01-01

    There have been increasing numbers of case reports of dengue infection with unusual manifestations. Such unusual manifestations including acute liver failure and encephalopathy could be manifested even in the absence of significant plasma leakage. Further, severe organ involvement including nervous system involvement indicates severe dengue infection. However, neurological manifestations of dengue fever are rare. This is the first case report of dengue infection with thalamic and basal ganglia involvement in Sri Lanka. PMID:27478661

  5. Two Functionally Distinct Networks of Gap Junction-Coupled Inhibitory Neurons in the Thalamic Reticular Nucleus

    OpenAIRE

    Lee, Seung-Chan; Patrick, Saundra L.; Richardson, Kristen A.; Connors, Barry W.

    2014-01-01

    Gap junctions (GJs) electrically couple GABAergic neurons of the forebrain. The spatial organization of neuron clusters coupled by GJs is an important determinant of network function, yet it is poorly described for nearly all mammalian brain regions. Here we used a novel dye-coupling technique to show that GABAergic neurons in the thalamic reticular nucleus (TRN) of mice and rats form two types of GJ-coupled clusters with distinctive patterns and axonal projections. Most clusters are elongate...

  6. Bilateral enhancing thalamic lesions in a 10 year old boy: case report

    OpenAIRE

    Olivero, W.; Deshmukh, P.; Gujrati, M

    1999-01-01

    A young boy presented with monoparesis of the left arm. MRI disclosed bilateral enhancing thalamic lesions. Biopsy results and subsequent clinical history were most compatible with postinfectious or acute disseminated encephalomyelitis. This represents one of the first cases of acute disseminated encephalomyelitis affecting the thalami, established by biopsy. This uncommon disease entity is reviewed and how it may affect the deep grey matter is described. 



  7. OCCLUSION OF ARTERY OF PERCHERON: A RARE AETIOLOGY OF BILATERAL THALAMIC INFARCT

    Directory of Open Access Journals (Sweden)

    Mane Makarand, Mane Priyanka, Mohite Rajsinh , Bhattad Prashant, Bangar Kushal, Mahajani Anup

    2015-10-01

    Full Text Available The Artery of Percheron, a rare anatomical variant of brain vascularisation, arises from the posterior cerebral artery. Occlusion of this artery leads to bilateral paramedian thalamic infarct leads to dysfunction of central nervous system. Incidence of bilateral thalamic infarct secondary to occlusion of artery of Percheron is unknown because of its rarity. Here we report a case of 35 year old female presented with altered state of consciousness and the underlying cause was occlusion of Artery of Percheron which leads to bilateral thalamic infarct detected on MRI scanning. It showed hyperintensities on T2W1 and FLAIR, and hypointensity on T1W1, restricted to bilateral ventromedial thalami showing corresponding area of high signal intensity on diffusion weighted images and hypointensity on apparent diffusion coefficient images indicating diffusion restriction, suggestive of infarct. On further investigation magnetic resonance arteriogram (MRA of the brain demonstrated a single common artery arising from the left P1 segment which divided into two branches distally supplying bilateral thalami. Patient became alright after 2 weeks of medical line of treatment.

  8. Fgf15 regulates thalamic development by controlling the expression of proneural genes.

    Science.gov (United States)

    Martinez-Ferre, Almudena; Lloret-Quesada, Cosme; Prakash, Nilima; Wurst, Wolfgang; Rubenstein, John L R; Martinez, Salvador

    2016-07-01

    The establishment of the brain structural complexity requires a precisely orchestrated interplay between extrinsic and intrinsic signals modulating cellular mechanisms to guide neuronal differentiation. However, little is known about the nature of these signals in the diencephalon, a complex brain region that processes and relays sensory and motor information to and from the cerebral cortex and subcortical structures. Morphogenetic signals from brain organizers regulate histogenetic processes such as cellular proliferation, migration, and differentiation. Sonic hedgehog (Shh) in the key signal of the ZLI, identified as the diencephalic organizer. Fgf15, the mouse gene orthologous of human, chick, and zebrafish Fgf19, is induced by Shh signal and expressed in the diencephalic alar plate progenitors during histogenetic developmental stages. This work investigates the role of Fgf15 signal in diencephalic development. In the absence of Fgf15, the complementary expression pattern of proneural genes: Ascl1 and Nng2, is disrupted and the GABAergic thalamic cells do not differentiate; in addition dorsal thalamic progenitors failed to exit from the mitotic cycle and to differentiate into neurons. Therefore, our findings indicate that Fgf15 is the Shh downstream signal to control thalamic regionalization, neurogenesis, and neuronal differentiation by regulating the expression and mutual segregation of neurogenic and proneural regulatory genes. PMID:26311466

  9. Myiasis in two box turtles.

    Science.gov (United States)

    Gould, W J; Georgi, M E

    1991-10-15

    Two eastern box turtles (Terrapene carolina carolina) were treated for myiasis caused by Sarcophaga cistudinis. The tortoises were examined because of swellings of the proximal cervical regions. Both fully recovered following surgical removal of multiple larvae. PMID:1748614

  10. DOPAMINE DEPLETION SLOWS RETINAL TRANSMISSION

    Science.gov (United States)

    In male hooded rats, depletion of norepinephrine and dopamine by a-methyl-paratyrosine (AMT) significantly increased the latencies of early peaks in flash-evoked potentials recorded from the visual cortex, lateral geniculate nucleus, and optic tract. These effects were not produc...

  11. Psychostimulants affect dopamine transmission through both dopamine transporter-dependent and independent mechanisms.

    Science.gov (United States)

    dela Peña, Ike; Gevorkiana, Ruzanna; Shi, Wei-Xing

    2015-10-01

    The precise mechanisms by which cocaine and amphetamine-like psychostimulants exert their reinforcing effects are not yet fully defined. It is widely believed, however, that these drugs produce their effects by enhancing dopamine neurotransmission in the brain, especially in limbic areas such as the nucleus accumbens, by inducing dopamine transporter-mediated reverse transport and/or blocking dopamine reuptake though the dopamine transporter. Here, we present the evidence that aside from dopamine transporter, non-dopamine transporter-mediated mechanisms also participate in psychostimulant-induced dopamine release and contribute to the behavioral effects of these drugs, such as locomotor activation and reward. Accordingly, psychostimulants could increase norepinephrine release in the prefrontal cortex, the latter then alters the firing pattern of dopamine neurons resulting in changes in action potential-dependent dopamine release. These alterations would further affect the temporal pattern of dopamine release in the nucleus accumbens, thereby modifying information processing in that area. Hence, a synaptic input to a nucleus accumbens neuron may be enhanced or inhibited by dopamine depending on its temporal relationship to dopamine release. Specific temporal patterns of dopamine release may also be required for certain forms of synaptic plasticity in the nucleus accumbens. Together, these effects induced by psychostimulants, mediated through a non-dopamine transporter-mediated mechanism involving norepinephrine and the prefrontal cortex, may also contribute importantly to the reinforcing properties of these drugs. PMID:26209364

  12. Thalamic involvement in the regulation of alpha EEG activity in psychiatric patients

    International Nuclear Information System (INIS)

    Aim: The thalamus is considered to be an important sub-cortical system involved in modulation of cortical activities. A relationship between thalamic activity and surface EEG was recently reported. In this study we evaluated a group of patients with psychiatric disorders who presented with asymmetric perfusion of the thalamus based on brain SPECT HMPAO studies. We predicted that asymmetrical activity of the thalamus would have asymmetrically distributed surface qEEG activity patterns. Materials and Methods: Twenty-three male psychiatric patients (age 54±14) with a primary diagnosis of depression and co-morbid substance abuse (83%) were studied with qEEG and HMPAO brain SPECT. The HMPAO ligand was administered while the EEG activity was being recorded. The SPECT analysis was conducted by means of ROI and SPM. ROI regions were determined based on the Talairach atlas coordinate system. ROI locations were verified by the automated utility, Talairach Demon. QEEG data was analyzed by a standardized protocol involving the NxLink database. Correlations between SPECT findings and qEEG absolute power were calculated. Results: Patients were divided into two groups based on thalamic perfusion patterns. Group 1 (Gr 1) had decreased perfusion to the right thalamus whereas Group 2 (Gr 2) had decreased perfusion to the left thalamus. SPM comparison of the patient groups to normal control subjects indicated significant findings. Comparison of Gr 1 to controls showed increased activity in the left temporal lobe and vermis. Decreased activity was observed in the left and right medial frontal lobes (right Brodmann 9;left Brodmann 6) as well as the left (Brodmann 30) and right (Brodmann 24) cingulate. Gr 2 comparison showed increased activity in the right middle frontal gyrus (Brodmann 10) and left inferior parietal lobe. Decreased activity was found in the left inferior frontal lobe (Brodmann 47). A positive correlation between alpha power and thalamic perfusion was identified in Gr

  13. Short-term synaptic plasticity in the nociceptive thalamic-anterior cingulate pathway

    Directory of Open Access Journals (Sweden)

    Vogt Brent A

    2009-09-01

    Full Text Available Abstract Background Although the mechanisms of short- and long-term potentiation of nociceptive-evoked responses are well known in the spinal cord, including central sensitization, there has been a growing body of information on such events in the cerebral cortex. In view of the importance of anterior cingulate cortex (ACC in chronic pain conditions, this review considers neuronal plasticities in the thalamocingulate pathway that may be the earliest changes associated with such syndromes. Results A single nociceptive electrical stimulus to the sciatic nerve induced a prominent sink current in the layer II/III of the ACC in vivo, while high frequency stimulation potentiated the response of this current. Paired-pulse facilitation by electrical stimulation of midline, mediodorsal and intralaminar thalamic nuclei (MITN suggesting that the MITN projection to ACC mediates the nociceptive short-term plasticity. The short-term synaptic plasticities were evaluated for different inputs in vitro where the medial thalamic and contralateral corpus callosum afferents were compared. Stimulation of the mediodorsal afferent evoked a stronger short-term synaptic plasticity and effectively transferred the bursting thalamic activity to cingulate cortex that was not true for contralateral stimulation. This short-term enhancement of synaptic transmission was mediated by polysynaptic pathways and NMDA receptors. Layer II/III neurons of the ACC express a short-term plasticity that involves glutamate and presynaptic calcium influx and is an important mechanism of the short-term plasticity. Conclusion The potentiation of ACC neuronal activity induced by thalamic bursting suggest that short-term synaptic plasticities enable the processing of nociceptive information from the medial thalamus and this temporal response variability is particularly important in pain because temporal maintenance of the response supports cortical integration and memory formation related to

  14. Thinking Outside the Box

    International Nuclear Information System (INIS)

    The World Nuclear Transport Institute was formed to fill a need to provide a dedicated vehicle for the radioactive transport and packaging industry sectors worldwide, to exchange information and ideas, all with a view to working toward consolidated industry positions on the key issues affecting safe, efficient and reliable transport. WNTI was also intended to be a strong voice for industry in those international and national bodies where deliberations on such transport safety issues take place. The very fact that companies, sometimes in competition with each other, were prepared to come together in this way, reflects two important points: firstly, it represents an acknowledgement on industry's part that safe, effective and reliable transport is the sine qua non, the absolute essential. And second, it is a recognition that it is enhanced to the extent that industry is able to collaborate to this end. This is thinking outside the box. Another important attribute of safety is 'stability'. Everyone likes to know where he or she stands. The radioactive materials packaging and transport industry thrives within a stable regulatory framework for safety. For a stable regulatory regime allows operators to be properly trained; it allows operators to become familiar with safety requirements, and to be at ease with them. Stability is conducive to safety and efficiency. Stability is good for business too - for stability in package and transport requirements allows sufficient time for a fair return on investment in expensive package design, manufacture, licensing and use over time. Stability should not, however, be opposed to creativity. From experience we can develop new thinking to improve efficiency as illustrated in examples of work related to the packaging and transport of Uranium Concentrates for instance.. Another example is work within WNTI on the thermal test requirements for the packaging of uranium hexafluoride. The robustness of packages is based on the risk factors

  15. 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

  16. Comparison of black-box, glass-box and open-box software for aiding conceptual understanding

    OpenAIRE

    Hosein, Anesa; Aczel, James; Clow, Doug; Richardson, John T. E.

    2008-01-01

    Three mathematical software types: black-box (no steps shown), glass-box (steps shown) and open-box (interactive steps) were used by 32 students to solve conceptual and procedural tasks on the computer via remote observation. Comparison of the three software types suggests that there is no difference in the scores that students receive for conceptual understanding tasks. Students using the black-box are more likely to explore answers than students using the glass and open-box software.

  17. Plate forming and break down pizza box

    Science.gov (United States)

    Pantisano, Frank; Devine, Scott M.

    1992-01-01

    A standard corrugated paper pizza box is provided with slit cuts cut through the top panel of the pizza box in a shape to form four circular serving plates with a beveled raised edge and cross slit cuts through the bottom panel of the pizza box separating the box into four essentially equal portions for easy disposal.

  18. Increased brain dopamine and dopamine receptors in schizophrenia

    International Nuclear Information System (INIS)

    In postmortem samples of caudate nucleus and nucleus accumbens from 48 schizophrenic patients, there were significant increases in both the maximum number of binding sites (Bmax) and the apparent dissociation constant (KD) for tritiated spiperone. The increase in apparent KD probably reflects the presence of residual neuroleptic drugs, but changes in Bmax for tritiated spiperone reflect genuine changes in receptor numbers. The increases in receptors were seen only in patients in whom neuroleptic medication had been maintained until the time of death, indicating that they may be entirely iatrogenic. Dopamine measurements for a larger series of schizophrenic and control cases (n greater than 60) show significantly increased concentrations in both the nucleus accumbens and caudate nucleus. The changes in dopamine were not obviously related to neuroleptic medication and, unlike the receptor changes, were most severe in younger patients

  19. First-aid boxes - Reminder

    CERN Multimedia

    GS Department

    2010-01-01

    With a view to ensuring optimum use of the first-aid boxes on the CERN site, we should like to remind you of various changes introduced in March 2009: The TSO of the buildings concerned is responsible for the first-aid boxes, including checking their contents.   First-aid boxes may be restocked ONLY at the CERN stores (SCEM No. 54.99.80). This is no longer possible at the Infirmary. The associated cost is charged to the Departments.   First-aid boxes should be used only for mild injuries. All other cases should be referred to the Medical Service Infirmary (Bldg. 57 – ground-floor, tel. 73802) between 8.00 a.m. and 5.30 p.m. or to the Fire and Rescue Service (tel. 74444). N.B.: This information does not apply to the red emergency first-aid boxes in the underground areas or to the emergency kits for use in the event of being splashed with hydrofluoric acid.

  20. Functional connectivity and dynamics of cortical-thalamic networks co-cultured in a dual compartment device

    Science.gov (United States)

    Kanagasabapathi, Thirukumaran T.; Massobrio, Paolo; Barone, Rocco Andrea; Tedesco, Mariateresa; Martinoia, Sergio; Wadman, Wytse J.; Decré, Michel M. J.

    2012-06-01

    Co-cultures containing dissociated cortical and thalamic cells may provide a unique model for understanding the pathophysiology in the respective neuronal sub-circuitry. In addition, developing an in vitro dissociated co-culture model offers the possibility of studying the system without influence from other neuronal sub-populations. Here we demonstrate a dual compartment system coupled to microelectrode arrays (MEAs) for co-culturing and recording spontaneous activities from neuronal sub-populations. Propagation of electrical activities between cortical and thalamic regions and their interdependence in connectivity is verified by means of a cross-correlation algorithm. We found that burst events originate in the cortical region and drive the entire cortical-thalamic network bursting behavior while mutually weak thalamic connections play a relevant role in sustaining longer burst events in cortical cells. To support these experimental findings, a neuronal network model was developed and used to investigate the interplay between network dynamics and connectivity in the cortical-thalamic system.

  1. Dopamine, uncertainty and TD learning

    Directory of Open Access Journals (Sweden)

    Duff Michael O

    2005-05-01

    Full Text Available Abstract Substantial evidence suggests that the phasic activities of dopaminergic neurons in the primate midbrain represent a temporal difference (TD error in predictions of future reward, with increases above and decreases below baseline consequent on positive and negative prediction errors, respectively. However, dopamine cells have very low baseline activity, which implies that the representation of these two sorts of error is asymmetric. We explore the implications of this seemingly innocuous asymmetry for the interpretation of dopaminergic firing patterns in experiments with probabilistic rewards which bring about persistent prediction errors. In particular, we show that when averaging the non-stationary prediction errors across trials, a ramping in the activity of the dopamine neurons should be apparent, whose magnitude is dependent on the learning rate. This exact phenomenon was observed in a recent experiment, though being interpreted there in antipodal terms as a within-trial encoding of uncertainty.

  2. Asymptotic Symmetries from finite boxes

    CERN Document Server

    Andrade, Tomas

    2015-01-01

    It is natural to regulate an infinite-sized system by imposing a boundary condition at finite distance, placing the system in a "box." This breaks symmetries, though the breaking is small when the box is large. One should thus be able to obtain the asymptotic symmetries of the infinite system by studying regulated systems. We provide concrete examples in the context of Einstein-Hilbert gravity (with negative or zero cosmological constant) by showing in 4 or more dimensions how the Anti-de Sitter and Poincar\\'e asymptotic symmetries can be extracted from gravity in a spherical box with Dirichlet boundary conditions. In 2+1 dimensions we obtain the full double-Virasoro algebra of asymptotic symmetries for AdS$_3$ and, correspondingly, the full Bondi-Metzner-Sachs (BMS) algebra for asymptotically flat space. In higher dimensions, a related approach may continue to be useful for constructing a good asymptotically flat phase space with BMS asymptotic symmetries.

  3. Asymptotic symmetries from finite boxes

    Science.gov (United States)

    Andrade, Tomás; Marolf, Donald

    2016-01-01

    It is natural to regulate an infinite-sized system by imposing a boundary condition at finite distance, placing the system in a 'box.' This breaks symmetries, though the breaking is small when the box is large. One should thus be able to obtain the asymptotic symmetries of the infinite system by studying regulated systems. We provide concrete examples in the context of Einstein-Hilbert gravity (with negative or zero cosmological constant) by showing in 4 or more dimensions how the anti-de Sitter and Poincaré asymptotic symmetries can be extracted from gravity in a spherical box with Dirichlet boundary conditions. In 2 + 1 dimensions we obtain the full double-Virasoro algebra of asymptotic symmetries for AdS3 and, correspondingly, the full Bondi-Metzner-Sachs (BMS) algebra for asymptotically flat space. In higher dimensions, a related approach may continue to be useful for constructing a good asymptotically flat phase space with BMS asymptotic symmetries.

  4. Identifying competencies of boxing coaches

    Directory of Open Access Journals (Sweden)

    Ioannis Tasiopoulos

    2014-10-01

    Full Text Available The purpose of this study was to find out the management skills required by boxing coaches to administrate their clubs. For the purposes of this study a scale was constructed which was answered by 98 boxing coaches. Explanatory factor analysis revealed seven factors: Communication-public relations (5 items, event management (4 items, management techniques (4 items, new technologies (4 items, prevention-safety (2 items, sport (5 items and sports facilities (2 items. The Cronbach of the scale was 0.85. The five competencies that rated by the coaches were: Supervisors of the area of training, maintaining excellent communication with athletes, using new technologies (e-mail, internet, handling disciplinary matters, accidents, complaints and reports on some sporting games and promoted harmony among athletes. We concluded that boxing coaches understand that the competencies required for meeting their obligations, were related to sports, prevention, safety and communications-public relations.

  5. Dopamine, Behavioral Economics, and Effort

    OpenAIRE

    Salamone, John D; Correa, Merce; Farrar, Andrew M.; Nunes, Eric J; Pardo, Marta

    2009-01-01

    There are numerous problems with the hypothesis that brain dopamine (DA) systems, particularly in the nucleus accumbens, directly mediate the rewarding or primary motivational characteristics of natural stimuli such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on hedonia and primary reward yielding to other concepts and lines of inquiry. The present review is focused upon the involve...

  6. Dopamine, behavioral economics, and effort

    OpenAIRE

    Salamone, John D; Merce Correa; Farrar, Andrew M.; Nunes, Eric J; Marta Pardo

    2009-01-01

    Abstract. There are numerous problems with the hypothesis that brain dopamine (DA) systems, particularly in the nucleus accumbens, directly mediate the rewarding or primary motivational characteristics of natural stimuli such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on hedonia and primary reward yielding to other concepts and lines of inquiry. The present review is focused upo...

  7. Distinct temporal spike and local field potential activities in the thalamic parafascicular nucleus of parkinsonian rats during rest and limb movement.

    Science.gov (United States)

    Wang, Min; Qu, Qingyang; He, Tingting; Li, Min; Song, Zhimin; Chen, Feiyu; Zhang, Xiao; Xie, Jinlu; Geng, Xiwen; Yang, Maoquan; Wang, Xiusong; Lei, Chengdong; Hou, Yabing

    2016-08-25

    Several studies have suggested that the thalamic centromedian-parafascicular (CM/PF or the PF in rodents) is implicated in the pathophysiology of Parkinson's disease (PD). However, inconsistent changes in the neuronal firing rate and pattern have been reported in parkinsonian animals. To investigate the impact of a dopaminergic cell lesion on PF extracellular discharge in behaving rats, the PF neural activities in the spike and local field potential (LFP) were recorded in unilaterally 6-hydroxydopamine- (6-OHDA) lesioned and neurologically intact control rats during rest and limb movement. During rest, the two PF neuronal subtypes was less spontaneously active, with no difference in the spike firing rates between the control and lesioned rats; only the lesioned rats reshaped their spike firing pattern. Furthermore, the simultaneously recorded LFP in the lesioned rats exhibited a significant increase in power at 12-35 and 35-70Hz and a decrease in power at 0.7-12Hz. During the execution of a voluntary movement, two subtypes of PF neurons were identified by a rapid increase in the discharge activity in both the control and lesioned rats. However, dopamine lesioning was associated with a decrease in neuronal spiking fire rate and reshaping in the firing pattern in the PF. The simultaneously recorded LFP activity exhibited a significant increase in power at 12-35Hz and a decrease in power at 0.7-12Hz compared with the control rats. These findings indicate that 6-OHDA induces modifications in PF spike and LFP activities in rats during rest and movement and suggest that PF dysfunction may be an important contributor to the pathophysiology of parkinsonian motor impairment. PMID:27238892

  8. Evolution of mammalian sensorimotor cortex: Thalamic projections to parietal cortical areas in Monodelphis domestica

    Directory of Open Access Journals (Sweden)

    James Clinton Dooley

    2015-01-01

    Full Text Available The current experiments build upon previous studies designed to reveal the network of parietal cortical areas present in the common mammalian ancestor. Understanding this ancestral network is essential for highlighting the basic somatosensory circuitry present in all mammals, and how this basic plan was modified to generate species specific behaviors. Our animal model, the short-tailed opossum (Monodelphis domestica, is a South American marsupial that has been proposed to have a similar ecological niche and morphology to the earliest common mammalian ancestor. In this investigation, we injected retrograde neuroanatomical tracers into the face and body representations of primary somatosensory cortex (S1, the rostral and caudal somatosensory fields (SR and SC, as well as a multimodal region (MM. Projections from different architectonically defined thalamic nuclei were then quantified. Our results provide further evidence to support the hypothesized basic mammalian plan of thalamic projections to S1, with the lateral and medial ventral posterior thalamic nuclei (VPl and VPm projecting to S1 body and S1 face, respectively. Additional strong projections are from the medial division of posterior nucleus (Pom. SR receives projections from several midline nuclei, including the medial dorsal, ventral medial nucleus, and Pom. SC and MM show similar patterns of connectivity, with projections from the ventral anterior and ventral lateral nuclei, VPm and VPl, and the entire posterior nucleus (medial and lateral. Notably, MM is distinguished from SC by relatively dense projections from the dorsal division of the lateral geniculate nucleus and pulvinar. We discuss the finding that S1 of the short-tailed opossum has a similar pattern of projections as other marsupials and mammals, but also some distinct projections not present in other mammals. Further we provide additional support for a primitive posterior parietal cortex which receives input from multiple

  9. 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.)

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

    International Nuclear Information System (INIS)

    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 (1H-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.)

  11. The treatment of brain stem and thalamic gliomas with 78 Gy of hyperfractionated radiation therapy

    International Nuclear Information System (INIS)

    Purpose: To see whether increasing the dose of hyperfractionated radiation therapy from 72 to 78 Gy would increase survival time in patients with gliomas, particularly those with brain stem or thalamic tumors. Methods: Seventy-eight patients with a clinical and radiographic diagnosis of a brain stem or thalamic glioma were enrolled in a trial to receive 78 Gy (1.0 Gy twice a day). Six patients with disease in other sites were also treated. The initial response to therapy was determined by comparing pretreatment magnetic resonance images and neurological examinations with those obtained within 2 weeks of completing therapy; subsequent responses were determined from bimonthly follow-up images. Time-to-tumor progression was measured from the date radiation therapy began until the date of documented radiographic or clinical progression. Survival time was measured from the date radiation therapy began until the date of death. Cox proportional hazards analysis was used to estimate the effects of specific variables on survival. Results: Of 81 evaluable patients, 68 received ≥ 76 Gy, 10 received between 70 and 75 Gy, and 3 received between 60 and 68 Gy. The overall response or stabilization rate was 70.4%. Tumor size decreased in 30.8% of patients; 39.5% had stable disease, and 29.6% had immediate progression. The median survival time was 12.7 months (16.1 months for adults and 10.8 months for children). The median time to tumor progression was 9.0 months (11.4 months for adults and 8.4 months for children). A duration of symptoms ≤ 2 months and a diffuse lesion were each associated with shorter survival and progression times. Conclusions: For patients with brain stem or thalamic gliomas, increasing the dose of radiation therapy from 72 to 78 Gy did not significantly improve survival. Different treatment strategies are clearly needed

  12. Thalamic functional connectivity predicts seizure laterality in individual TLE patients: Application of a biomarker development strategy

    Science.gov (United States)

    Barron, Daniel S.; Fox, Peter T.; Pardoe, Heath; Lancaster, Jack; Price, Larry R.; Blackmon, Karen; Berry, Kristen; Cavazos, Jose E.; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas

    2014-01-01

    Noninvasive markers of brain function could yield biomarkers in many neurological disorders. Disease models constrained by coordinate-based meta-analysis are likely to increase this yield. Here, we evaluate a thalamic model of temporal lobe epilepsy that we proposed in a coordinate-based meta-analysis and extended in a diffusion tractography study of an independent patient population. Specifically, we evaluated whether thalamic functional connectivity (resting-state fMRI-BOLD) with temporal lobe areas can predict seizure onset laterality, as established with intracranial EEG. Twenty-four lesional and non-lesional temporal lobe epilepsy patients were studied. No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons). Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength) successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional) predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional) achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses. PMID:25610790

  13. Abnormal functional integration of thalamic low frequency oscillation in the BOLD signal after acute heroin treatment.

    Science.gov (United States)

    Denier, Niklaus; Schmidt, André; Gerber, Hana; Vogel, Marc; Huber, Christian G; Lang, Undine E; Riecher-Rossler, Anita; Wiesbeck, Gerhard A; Radue, Ernst-Wilhelm; Walter, Marc; Borgwardt, Stefan

    2015-12-01

    Heroin addiction is a severe relapsing brain disorder associated with impaired cognitive control, including deficits in attention allocation. The thalamus has a high density of opiate receptors and is critically involved in orchestrating cortical activity during cognitive control. However, there have been no studies on how acute heroin treatment modulates thalamic activity. In a cross-over, double-blind, vehicle-controlled study, 29 heroin-maintained outpatients were studied after heroin and placebo administration, while 20 healthy controls were included for the placebo condition only. Resting-state functional magnetic resonance imaging was used to analyze functional integration of the thalamus by three different resting state analysis techniques. Thalamocortical functional connectivity (FC) was analyzed by seed-based correlation, while intrinsic thalamic oscillation was assessed by analysis of regional homogeneity (ReHo) and the fractional amplitude of low frequency fluctuations (fALFF). Relative to the placebo treatment and healthy controls, acute heroin administration reduced thalamocortical FC to cortical regions, including the frontal cortex, while the reductions in FC to the mediofrontal cortex, orbitofrontal cortex, and frontal pole were positively correlated with the plasma level of morphine, the main psychoactive metabolite of heroin. Furthermore, heroin treatment was associated with increased thalamic ReHo and fALFF values, whereas fALFF following heroin exposure correlated negatively with scores of attentional control. The heroin-associated increase in fALFF was mainly dominated by slow-4 (0.027-0.073 Hz) oscillations. Our findings show that there are acute effects of heroin within the thalamocortical system and may shed new light on the role of the thalamus in cognitive control in heroin addiction. Future research is needed to determine the underlying physiological mechanisms and their role in heroin addiction. PMID:26441146

  14. Thalamic hemorrhage in a 4-year-old child induced by nephro-vascular hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, E.; Savasta, S.; Torcetta, F.; Solmi, M.; Beluffi, G.; Gajno, T.M.

    1989-08-01

    A child affected by cardiomyopathy from the age of 12 months suddenly manifested right hemiparesis and dysarthria at the age of 48/12 years. Emergency brain CT showed a hemorrhage in progress in the left thalamic area. A serve from of hypertension was concomitant and resisted all pharmacological treatment. Retrograde transfemural aortography pointed out an atrophy of the right renal artery. This finding, together with the high renin and aldosterone values, indicated a nephrogenic hypertension causing both the cardiomyopathy found at 12 months of age and the endocranial hermorrhage. Right nephrectomy led to the normalization of blood pressure. (orig.).

  15. Translaminar Inhibitory Cells Recruited by Layer 6 Cortico-Thalamic Neurons Suppress Visual Cortex

    OpenAIRE

    Bortone, Dante S.; Olsen, Shawn R.; Scanziani, Massimo

    2014-01-01

    In layer 6 (L6), a principal output layer of the mammalian cerebral cortex, a population of excitatory neurons defined by the NTSR1-Cre mouse line inhibit cortical responses to visual stimuli. Here we show that of the two major types of excitatory neurons existing in L6, the NTSR1-Cre line selectively targets those whose axon innervate both cortex and thalamus and not those whose axons remain within the cortex. These cortico-thalamic neurons mediate widespread inhibition across all cortical l...

  16. "Blue is music to my ears": multimodal synesthesias after a thalamic stroke.

    Science.gov (United States)

    Fornazzari, Luis; Fischer, Corinne E; Ringer, Lee; Schweizer, Tom A

    2012-01-01

    Acquired synesthesias have been reported in association with deafferentation of the visual system, temporal lobe seizures, and the use of psychedelics. Based on our review of the literature, the appearance of synesthesias after a thalamic stroke has been reported only once. We present the case of a 45-year-old hypertensive male who, 9 months after a hemorrhagic stroke involving the left lateral posterior nucleus of the thalamus developed persistent sound-tactile, sound-color, and grapheme-gustatory synesthesias. Moreover, the patient noted that even thinking about a sensory stimulus could trigger the experience of another sensory modality, a conceptual type of synesthesia. PMID:22111936

  17. Thalamic hemorrhage in a 4-year-old child induced by nephro-vascular hypertension

    International Nuclear Information System (INIS)

    A child affected by cardiomyopathy from the age of 12 months suddenly manifested right hemiparesis and dysarthria at the age of 48/12 years. Emergency brain CT showed a hemorrhage in progress in the left thalamic area. A serve from of hypertension was concomitant and resisted all pharmacological treatment. Retrograde transfemural aortography pointed out an atrophy of the right renal artery. This finding, together with the high renin and aldosterone values, indicated a nephrogenic hypertension causing both the cardiomyopathy found at 12 months of age and the endocranial hermorrhage. Right nephrectomy led to the normalization of blood pressure. (orig.)

  18. Innovations in Los Alamos alpha box design

    International Nuclear Information System (INIS)

    Destructive examinations of irradiated fuel pins containing plutonium fuel must be performed in shielded hot cells with strict provisions for containing the plutonium. Alpha boxes provide containment for the plutonium, toxic fission products, and other hazardous highly radioactive materials. The alpha box contains windows for viewing and a variety of transfer systems specially designed to allow transfers in and out of the alpha box without spread of the hazardous materials that are contained in the box. Alpha boxes have been in use in the Wing 9 hot cells at Los Alamos National Laboratory for more than 20 years. Features of the newly designed alpha boxes are presented

  19. Innovations in Los Alamos alpha box design

    Energy Technology Data Exchange (ETDEWEB)

    Ledbetter, J.M.; Dowler, K.E.; Cook, J.H.

    1985-01-01

    Destructive examinations of irradiated fuel pins containing plutonium fuel must be performed in shielded hot cells with strict provisions for containing the plutonium. Alpha boxes provide containment for the plutonium, toxic fission products, and other hazardous highly radioactive materials. The alpha box contains windows for viewing and a variety of transfer systems specially designed to allow transfers in and out of the alpha box without spread of the hazardous materials that are contained in the box. Alpha boxes have been in use in the Wing 9 hot cells at Los Alamos National Laboratory for more than 20 years. Features of the newly designed alpha boxes are presented.

  20. Partons of a spherical box

    International Nuclear Information System (INIS)

    Calculation of parton distributions in the 'cavity approximation' to the MIT bag model gives a divergent sum of positive terms. In this version of the model the flexible movable bag is replaced by an inflexible immovable box. This suggests that Bjorken scaling does not hold for the deep inelastic scattering in this version of the model. (K.A.)

  1. On the Dirichlet's Box Principle

    Science.gov (United States)

    Poon, Kin-Keung; Shiu, Wai-Chee

    2008-01-01

    In this note, we will focus on several applications on the Dirichlet's box principle in Discrete Mathematics lesson and number theory lesson. In addition, the main result is an innovative game on a triangular board developed by the authors. The game has been used in teaching and learning mathematics in Discrete Mathematics and some high schools in…

  2. A Box Full of Kisses

    Institute of Scientific and Technical Information of China (English)

    崔增印

    2008-01-01

    The story goes that some time ago,a man pun- ished his 3-year-old daughter for wasting a roll of gold wrapping paper.Money was tight and he became infuriated when the child tried to decorate a box to put under the Christmas tree.Nevertheless,the little girl brought the gift to

  3. WNT Protein-independent Constitutive Nuclear Localization of β-Catenin Protein and Its Low Degradation Rate in Thalamic Neurons*

    OpenAIRE

    Misztal, Katarzyna; Wisniewska, Marta B.; Ambrozkiewicz, Mateusz; Nagalski, Andrzej; Kuznicki, Jacek

    2011-01-01

    Nuclear localization of β-catenin is a hallmark of canonical Wnt signaling, a pathway that plays a crucial role in brain development and the neurogenesis of the adult brain. We recently showed that β-catenin accumulates specifically in mature thalamic neurons, where it regulates the expression of the Cav3.1 voltage-gated calcium channel gene. Here, we investigated the mechanisms underlying β-catenin accumulation in thalamic neurons. We report that a lack of soluble factors produced either by ...

  4. Clinical, neuropsychological, and pre-stimulus dorsomedial thalamic nucleus electrophysiological data in deep brain stimulation patients.

    Science.gov (United States)

    Sweeney-Reed, Catherine M; Zaehle, Tino; Voges, Jürgen; Schmitt, Friedhelm C; Buentjen, Lars; Kopitzki, Klaus; Richardson-Klavehn, Alan; Hinrichs, Hermann; Heinze, Hans-Jochen; Knight, Robert T; Rugg, Michael D

    2016-09-01

    The data presented here comprise clinical, neuropsychological, and intrathalamic electrophysiological data from 7 patients with pharmacoresistant focal epilepsy and are related to the article "Pre-stimulus thalamic theta power predicts human memory formation" C.M. Sweeney-Reed, T. Zaehle, J. Voges, F.C. Schmitt, L. Buentjen, K. Kopitzki, et al. (2016) [1]. The patients participated in a memory paradigm after receiving electrodes implanted in the DMTN due to the surgical approach taken in electrode insertion for deep brain stimulation of the anterior thalamic nucleus. Epilepsy duration and pre-operative neuropsychological tests provide an indication of the profile of patients receiving intrathalamic electrode implantation and the memory capabilities in such a patient group. The electrophysiological data were recorded from the right DMTN preceding stimulus presentation during intentional memory encoding. The patients viewed a series of photographic scenes, which they judged as indoors or outdoors. The 900 ms epochs prior to stimulus presentation were labeled as preceding successful or unsuccessful subsequent memory formation according to a subsequent memory test for the items. The difference between theta power preceding successful versus unsuccessful subsequent memory formation is shown against time for each patient individually. PMID:27508216

  5. Dural arteriovenous fistula-induced thalamic dementia: report of 4 cases.

    Science.gov (United States)

    Holekamp, Terrence F; Mollman, Matthew E; Murphy, Rory K J; Kolar, Grant R; Kramer, Neha M; Derdeyn, Colin P; Moran, Christopher J; Perrin, Richard J; Rich, Keith M; Lanzino, Giuseppe; Zipfel, Gregory J

    2016-06-01

    Nonhemorrhagic neurological deficits are underrecognized symptoms of intracranial dural arteriovenous fistulas (dAVFs) having cortical venous drainage. These symptoms are the consequence of cortical venous hypertension and portend a clinical course with increased risk of neurological morbidity and mortality. One rarely documented and easily misinterpreted type of nonhemorrhagic neurological deficit is progressive dementia, which can result from venous hypertension in the cortex or in bilateral thalami. The latter, which is due to dAVF drainage into the deep venous system, is the less common of these 2 dementia syndromes. Herein, the authors report 4 cases of dAVF with venous drainage into the vein of Galen causing bithalamic edema and rapidly progressive dementia. Two patients were treated successfully with endovascular embolization, and the other 2 patients were treated successfully with endovascular embolization followed by surgery. The radiographic abnormalities and presenting symptoms rapidly resolved after dAVF obliteration in all 4 cases. Detailed descriptions of these 4 cases are presented along with a critical review of 15 previously reported cases. In our analysis of these 19 published cases, the following were emphasized: 1) the clinical and radiographic differences between dAVF-induced thalamic versus cortical dementia syndromes; 2) the differential diagnosis and necessary radiographic workup for patients presenting with a rapidly progressive thalamic dementia syndrome; 3) the frequency at which delays in diagnosis occurred and potentially dangerous and avoidable diagnostic procedures were used; and 4) the rapidity and completeness of symptom resolution following dAVF treatment. PMID:26587655

  6. 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.

  7. A case of herpes simplex encephalitis(HSE) with a thalamic lesion

    International Nuclear Information System (INIS)

    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. (author)

  8. Chronic bilateral thalamic stimulation: a new therapeutic approach in intractable Tourette syndrome. Report of three cases.

    Science.gov (United States)

    Visser-Vandewalle, Veerle; Temel, Yasin; Boon, Peter; Vreeling, Fred; Colle, Henry; Hoogland, Govert; Groenewegen, Henk J; van der Linden, Chris

    2003-12-01

    Based on the results of thalamotomies described by Hassler in 1970, the authors performed bilateral thalamic high-frequency stimulation (HFS) in three patients with intractable Tourette syndrome (TS). In this report they describe the long-term effects. Three male patients (42, 28, and 45 years of age) had manifested motor and vocal tics since early childhood. The diagnosis of TS was made according to the criteria of the Tourette Syndrome Classification Study Group. Any drug or alternative treatment had been either ineffective or only temporarily effective in all three patients. There was no serious comorbidity. The target for stimulation was chosen at the level of the centromedian nucleus, substantia periventricularis, and nucleus ventrooralis internus. After 2 weeks of test stimulation, the pulse generators were implanted. After a follow-up period of 5 years in the patient in Case 1, 1 year in the patient in Case 2, and 8 months in the patient in Case 3, all major motor and vocal tics had disappeared and no serious complications had occurred. When stimulation was applied at the voltage necessary to achieve an optimal result on the tics, a slight sedative effect was noted in all three patients. In the patients in Cases 1 and 3 there were stimulation-induced changes in sexual behavior. Chronic thalamic HFS may be an effective and safe treatment for medically intractable TS in adult patients. Unwanted stimulation-induced side effects may occur. PMID:14705742

  9. Early life stress predicts thalamic hyperconnectivity: A transdiagnostic study of global connectivity.

    Science.gov (United States)

    Philip, Noah S; Tyrka, Audrey R; Albright, Sarah E; Sweet, Lawrence H; Almeida, Jorge; Price, Lawrence H; Carpenter, Linda L

    2016-08-01

    Early life stress (ELS) is an established risk factor for psychiatric illness and is associated with altered functional connectivity within- and between intrinsic neural networks. The widespread nature of these disruptions suggests that broad imaging measures of neural connectivity, such as global based connectivity (GBC), may be particularly appropriate for studies of this population. GBC is designed to identify brain regions having maximal functional connectedness with the rest of the brain, and alterations in GBC may reflect a restriction or broadening of network synchronization. We evaluated whether ELS severity predicted GBC in a sample (N = 46) with a spectrum of ELS exposure. Participants included healthy controls without ELS, those with at least moderate ELS but without psychiatric disorders, and a group of patients with ELS- related psychiatric disorders. The spatial distribution of GBC peaked in regions of the salience and default mode networks, and ELS severity predicted increased GBC of the left thalamus (corrected p < 0.005, r = 0.498). Thalamic connectivity was subsequently evaluated and revealed reduced connectivity with the salience network, particularly the dorsal anterior cingulate cortex (corrected p < 0.005), only in the patient group. These findings support a model of disrupted thalamic connectivity in ELS and trauma-related negative affect states, and underscore the importance of a transdiagnostic, dimensional neuroimaging approach to understanding the sequelae of trauma exposure. PMID:27214526

  10. Clinical appraisal of stereotactic hematoma aspiration surgery for hypertensive thalamic hemorrhage

    International Nuclear Information System (INIS)

    Three hundred and four patients with hypertensive thalamic hemorrhage were managed by medical treatment, ventricular drainage, or CT-controlled stereotactic aspiration surgery (AS). The therapeutic results of the 6-month outcome were analyzed and correlated with the volume of the hematoma. A hematoma volume of 20 ml was thought to be the critical size in determining whether the outcome would be favorable or unfavorable. Indications for AS are suggested as follows. In patients with a small-sized hematoma having a volume of less than 10 ml use of AS should be restricted to patients with severe paralysis or other neurological complications and the elderly (aged 70 years or older). For patients with a medium-sized hematoma having a volume between 10 ml and 20 ml, AS is indicated for patients having severe paralysis and disturbances of consciousness. For patients with a large-sized hematoma having a volume of 20 ml or more, AS increases not only the survival rate of patients but also reduces the number of bedridden patients. We conclude that AS opens up a new avenue of surgical treatment for hypertensive thalamic hemorrhage, which has been no indication for hematoma evacuation by conventional craniotomy. (author)

  11. Dynamics of action potential initiation in the GABAergic thalamic reticular nucleus in vivo.

    Directory of Open Access Journals (Sweden)

    Fabián Muñoz

    Full Text Available Understanding the neural mechanisms of action potential generation is critical to establish the way neural circuits generate and coordinate activity. Accordingly, we investigated the dynamics of action potential initiation in the GABAergic thalamic reticular nucleus (TRN using in vivo intracellular recordings in cats in order to preserve anatomically-intact axo-dendritic distributions and naturally-occurring spatiotemporal patterns of synaptic activity in this structure that regulates the thalamic relay to neocortex. We found a wide operational range of voltage thresholds for action potentials, mostly due to intrinsic voltage-gated conductances and not synaptic activity driven by network oscillations. Varying levels of synchronous synaptic inputs produced fast rates of membrane potential depolarization preceding the action potential onset that were associated with lower thresholds and increased excitability, consistent with TRN neurons performing as coincidence detectors. On the other hand the presence of action potentials preceding any given spike was associated with more depolarized thresholds. The phase-plane trajectory of the action potential showed somato-dendritic propagation, but no obvious axon initial segment component, prominent in other neuronal classes and allegedly responsible for the high onset speed. Overall, our results suggest that TRN neurons could flexibly integrate synaptic inputs to discharge action potentials over wide voltage ranges, and perform as coincidence detectors and temporal integrators, supported by a dynamic action potential threshold.

  12. Cosmetic Foot Surgery: Fashion's Pandora's Box

    Science.gov (United States)

    ... News, Videos & Podcasts » Articles » Text Size Print Bookmark Cosmetic Foot Surgery: Fashion’s Pandora’s Box? Cosmetic Foot Surgery: Fashion’s Pandora’s Box? Foot and Ankle Surgeons Warn ...

  13. Dopamine: burning the candle at both ends.

    Science.gov (United States)

    Pearson, John M; Platt, Michael L

    2013-09-01

    Dopamine neurons are well known for signaling reward-prediction errors. In this issue, Matsumoto and Takada (2013) show that some dopamine neurons also signal salient events during progression through a visual search task requiring working memory and sustained attention. PMID:24011998

  14. Computational systems analysis of dopamine metabolism.

    Directory of Open Access Journals (Sweden)

    Zhen Qi

    Full Text Available A prominent feature of Parkinson's disease (PD is the loss of dopamine in the striatum, and many therapeutic interventions for the disease are aimed at restoring dopamine signaling. Dopamine signaling includes the synthesis, storage, release, and recycling of dopamine in the presynaptic terminal and activation of pre- and post-synaptic receptors and various downstream signaling cascades. As an aid that might facilitate our understanding of dopamine dynamics in the pathogenesis and treatment in PD, we have begun to merge currently available information and expert knowledge regarding presynaptic dopamine homeostasis into a computational model, following the guidelines of biochemical systems theory. After subjecting our model to mathematical diagnosis and analysis, we made direct comparisons between model predictions and experimental observations and found that the model exhibited a high degree of predictive capacity with respect to genetic and pharmacological changes in gene expression or function. Our results suggest potential approaches to restoring the dopamine imbalance and the associated generation of oxidative stress. While the proposed model of dopamine metabolism is preliminary, future extensions and refinements may eventually serve as an in silico platform for prescreening potential therapeutics, identifying immediate side effects, screening for biomarkers, and assessing the impact of risk factors of the disease.

  15. The Heuristic Interpretation of Box Plots

    Science.gov (United States)

    Lem, Stephanie; Onghena, Patrick; Verschaffel, Lieven; Van Dooren, Wim

    2013-01-01

    Box plots are frequently used, but are often misinterpreted by students. Especially the area of the box in box plots is often misinterpreted as representing number or proportion of observations, while it actually represents their density. In a first study, reaction time evidence was used to test whether heuristic reasoning underlies this…

  16. Box-shaped halophilic bacteria.

    OpenAIRE

    Javor, B; Requadt, C; Stoeckenius, W

    1982-01-01

    Three morphologically similar strains of halophilic, box-shaped procaryotes have been isolated from brines collected in the Sinai, Baja California (Mexico), and southern California (United States). Although the isolates in their morphology resemble Walsby's square bacteria, which are a dominant morphological type in the Red Sea and Baja California brines, they are probably not identical to them. The cells show the general characteristics of extreme halophiles and archaebacteria. They contain ...

  17. Broken links and black boxes

    DEFF Research Database (Denmark)

    Sindbæk, Søren Michael

    2013-01-01

    Long-distance communication has emerged as a particular focus for archaeological exploration using network theory, analysis, and modelling. Initial attempts to adapt methods from social network analysis to archaeological data have, however, struggled to produce decisive results. This paper argues...... ruined network from observable distributions and patterns of association in the archaeological record. In formal terms this is not a problem of network analysis, but network synthesis: the classic problem of cracking codes or reconstructing black-box circuits....

  18. Das k-Box-Produkt

    OpenAIRE

    Elser, Stefan

    2011-01-01

    Ziel dieser Doktorarbeit ist es, bekannte und oft verwendete Eigenschaften des Tychonow-Produkts in analoger Form für das k-Box-Produkt zu beweisen, was bisher noch nicht geschehen ist, und die Verbindung zwischen der Infinitären Kombinatorik und der Topologie zu vertiefen. In der Infinitären Kombinatorik, ein Zweig der modernen Mengenlehre, bedient man sich gerne topologischer Begriffe, um einerseits Ergebnisse zu verdeutlichen und um andererseits den sehr abstrakten kombinatorischen Be...

  19. 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 exam

  20. MM2-thalamic Creutzfeldt-Jakob disease: neuropathological, biochemical and transmission studies identify a distinctive prion strain.

    Science.gov (United States)

    Moda, Fabio; Suardi, Silvia; Di Fede, Giuseppe; Indaco, Antonio; Limido, Lucia; Vimercati, Chiara; Ruggerone, Margherita; Campagnani, Ilaria; Langeveld, Jan; Terruzzi, Alessandro; Brambilla, Antonio; Zerbi, Pietro; Fociani, Paolo; Bishop, Matthew T; Will, Robert G; Manson, Jean C; Giaccone, Giorgio; Tagliavini, Fabrizio

    2012-09-01

    In Creutzfeldt-Jakob disease (CJD), molecular typing based on the size of the protease resistant core of the disease-associated prion protein (PrP(Sc) ) and the M/V polymorphism at codon 129 of the PRNP gene correlates with the clinico-pathologic subtypes. Approximately 95% of the sporadic 129MM CJD patients are characterized by cerebral deposition of type 1 PrP(Sc) and correspond to the classic clinical CJD phenotype. The rare 129MM CJD patients with type 2 PrP(Sc) are further subdivided in a cortical and a thalamic form also indicated as sporadic fatal insomnia. We observed two young patients with MM2-thalamic CJD. Main neuropathological features were diffuse, synaptic PrP immunoreactivity in the cerebral cortex and severe neuronal loss and gliosis in the thalamus and olivary nucleus. Western blot analysis showed the presence of type 2A PrP(Sc) . Challenge of transgenic mice expressing 129MM human PrP showed that MM2-thalamic sporadic CJD (sCJD) was able to transmit the disease, at variance with MM2-cortical sCJD. The affected mice showed deposition of type 2A PrP(Sc) , a scenario that is unprecedented in this mouse line. These data indicate that MM2-thalamic sCJD is caused by a prion strain distinct from the other sCJD subtypes including the MM2-cortical form. PMID:22288561

  1. Pramipexole, a dopamine D2 autoreceptor agonist, decreases the extracellular concentration of dopamine in vivo.

    Science.gov (United States)

    Carter, A J; Müller, R E

    1991-07-23

    Pramipexole (SND 919) is a dopamine D2 autoreceptor agonist which is structurally related to talipexole (B-HT 920), a potential antipsychotic agent. The aim of this study was to investigate the effects of pramipexole on the extracellular concentration of dopamine in vivo. Dopamine and its metabolites, 3,4-dihydrophenylacetic acid and homovanillic acid, were measured in the anterior striatum of freely moving rats by microdialysis and high-performance liquid chromatography with electrochemical detection. Pramipexole (30 and 100 micrograms/kg) caused long-lasting decreases in the extracellular concentrations of dopamine and its metabolites. Talipexole (30 micrograms/kg) produced similar effects. Sulpiride (5 mg/kg), a selective dopamine D2 antagonist, caused a transient increase in the concentration of dopamine and long-lasting increases in the concentrations of its metabolites; it also reversed the effects of pramipexole. SCH-23390 (100 micrograms/kg), a selective dopamine D1 receptor antagonist, caused a transient increase in the concentration of dopamine but did not affect the concentrations of the metabolites. SCH-23390 failed to reverse the effects of pramipexole. These results indicate that pramipexole reduces the extracellular concentrations of dopamine and its metabolites in vivo through a reversible interaction with the dopamine D2 receptor. PMID:1685123

  2. Urinary dopamine in man and rat: effects of inorganic salts on dopamine excretion.

    Science.gov (United States)

    Ball, S G; Oats, N S; Lee, M R

    1978-08-01

    1. Plasma and urine free dopamine (3,4-dihydroxyphenethylamine) were measured in six normal male volunteer subjects and the urinary clearance of dopamine was calculated for each subject. 2. The excretion rates for free dopamine in man were greater than could be explained by simple renal clearance. It was concluded that free dopamine must, therefore, be formed in the kidney. 3. Changes in urinary dopamine excretion were studied in four groups of rats initially maintained on low sodium diet and then given equimolar dietary supplements of NaCl, NaHCO3, KCl or NH4Cl, to study the specificity of the previously observed increase in dopamine excretion after increased dietary NaCl. 4. The mean dopamine excretion increased significantly in rats given NaCl, KCl and NH4Cl, whereas dopamine excretion decreased in those given NaHCO3. 5. The failure of dopamine excretion to rise in response to loading with NaHCO3 was unexpected, and argues against a simple effect of volume expansion by the sodium ion. The increase in dopamine excretion with KCl and NH4Cl showed that this response was not specific to the sodium ion. PMID:28196

  3. Dopamine beta-hydroxylase deficiency

    Directory of Open Access Journals (Sweden)

    Senard Jean-Michel

    2006-03-01

    Full Text Available Abstract Dopamine beta-hydroxylase (DβH deficiency is a very rare form of primary autonomic failure characterized by a complete absence of noradrenaline and adrenaline in plasma together with increased dopamine plasma levels. The prevalence of DβH deficiency is unknown. Only a limited number of cases with this disease have been reported. DβH deficiency is mainly characterized by cardiovascular disorders and severe orthostatic hypotension. First symptoms often start during a complicated perinatal period with hypotension, muscle hypotonia, hypothermia and hypoglycemia. Children with DβH deficiency exhibit reduced ability to exercise because of blood pressure inadaptation with exertion and syncope. Symptoms usually worsen progressively during late adolescence and early adulthood with severe orthostatic hypotension, eyelid ptosis, nasal stuffiness and sexual disorders. Limitation in standing tolerance, limited ability to exercise and traumatic morbidity related to falls and syncope may represent later evolution. The syndrome is caused by heterogeneous molecular alterations of the DBH gene and is inherited in an autosomal recessive manner. Restoration of plasma noradrenaline to the normal range can be achieved by therapy with the synthetic precursor of noradrenaline, L-threo-dihydroxyphenylserine (DOPS. Oral administration of 100 to 500 mg DOPS, twice or three times daily, increases blood pressure and reverses the orthostatic intolerance.

  4. Polypharmacology of dopamine receptor ligands.

    Science.gov (United States)

    Butini, S; Nikolic, K; Kassel, S; Brückmann, H; Filipic, S; Agbaba, D; Gemma, S; Brogi, S; Brindisi, M; Campiani, G; Stark, H

    2016-07-01

    Most neurological diseases have a multifactorial nature and the number of molecular mechanisms discovered as underpinning these diseases is continuously evolving. The old concept of developing selective agents for a single target does not fit with the medical need of most neurological diseases. The development of designed multiple ligands holds great promises and appears as the next step in drug development for the treatment of these multifactorial diseases. Dopamine and its five receptor subtypes are intimately involved in numerous neurological disorders. Dopamine receptor ligands display a high degree of cross interactions with many other targets including G-protein coupled receptors, transporters, enzymes and ion channels. For brain disorders like Parkinsońs disease, schizophrenia and depression the dopaminergic system, being intertwined with many other signaling systems, plays a key role in pathogenesis and therapy. The concept of designed multiple ligands and polypharmacology, which perfectly meets the therapeutic needs for these brain disorders, is herein discussed as a general ligand-based concept while focusing on dopaminergic agents and receptor subtypes in particular. PMID:27234980

  5. Dopamine-transporter SPECT and Dopamine-D2-receptor SPECT in basal ganglia diseases

    International Nuclear Information System (INIS)

    The basal ganglia comprise a group of subcortical nuclei, which are essential for motor control. Dysfunction of these areas, especially in dopaminergic transmission, results in disordered movement and neurological diseases such as Parkinson's disease, Wilson's disease, or Huntington disease. Positron emission tomography and single photon emission computed tomography (SPECT) have enhanced the understanding of the underlying pathophysiology, but they much more contribute to the early differential diagnosis of patients suffering from Parkinsonian syndrome in routine care. The present article provides dopamine transporter and D2 receptor SPECT findings in selected movement disorders. (orig.)

  6. 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

  7. Medial thalamic 18-FDG uptake following inescapable shock correlates with subsequent learned helpless behavior

    International Nuclear Information System (INIS)

    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[18F]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 correlations were found

  8. The findings of Tc-99m ECD brain perfusion SPECT in the patients with left anterior thalamic infarction

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Y. A.; Kim, S. H.; Sohn, H. S.; Jeong, S. G. [The Catholic University of Korea, Seoul (Korea, Republic of)

    2005-07-01

    The thalamus has multiple connections with areas of the cerebral cortex involved in arousal and cognition. Thalamic damage has been reported to be associated with variable neuropsychological dysfunctions and dementia. This study evaluates the changes of regional cerebral blood flow (rCBF) by using SPM analysis of brain perfusion SPECT and examining the neuropsychological abnormalities of 4 patients with anterior thalamic infarctions. Four patients with left anterior thalamic infarctions and eleven normal controls were evaluated. K-MMSE and the Seoul Neuropsychological Screening Battery were performed within 2 days after stroke. The normalized SPECT data of 4 patients were compared to those of 11 controls for the detection of areas with decreased rCBF by SPM analysis. All 4 patients showed anterograde amnesia in their verbal memory, which was not improved by recognition. Dysexecutive features were occasionally present, such as decreased word fluency and impaired Stroop test results. SPM analysis revealed decreased rCBF in the left supra marginal gyrus, the superior temporal gyrus, the middle and inferior frontal gyrus, the medial dorsal and anterior nucleus of the left thalamus. The changes of rCBF in patients with left anterior thalamic infarctions may be due to the remote suppression on metabolism by the interruption of the cortico-subcortical circuit, which connects the anterior thalamic nucleus and various cortical areas. The executive dysfunction and dysnomia may be caused by the left dorsolateral frontal dysfunction of the thalamo-cortical circuit. Anterograde amnesia with storage deficit may be caused by the disruption of mamillothalamic tract.

  9. The findings of Tc-99m ECD brain perfusion SPECT in the patients with left anterior thalamic infarction

    International Nuclear Information System (INIS)

    The thalamus has multiple connections with areas of the cerebral cortex involved in arousal and cognition. Thalamic damage has been reported to be associated with variable neuropsychological dysfunctions and dementia. This study evaluates the changes of regional cerebral blood flow (rCBF) by using SPM analysis of brain perfusion SPECT and examining the neuropsychological abnormalities of 4 patients with anterior thalamic infarctions. Four patients with left anterior thalamic infarctions and eleven normal controls were evaluated. K-MMSE and the Seoul Neuropsychological Screening Battery were performed within 2 days after stroke. The normalized SPECT data of 4 patients were compared to those of 11 controls for the detection of areas with decreased rCBF by SPM analysis. All 4 patients showed anterograde amnesia in their verbal memory, which was not improved by recognition. Dysexecutive features were occasionally present, such as decreased word fluency and impaired Stroop test results. SPM analysis revealed decreased rCBF in the left supra marginal gyrus, the superior temporal gyrus, the middle and inferior frontal gyrus, the medial dorsal and anterior nucleus of the left thalamus. The changes of rCBF in patients with left anterior thalamic infarctions may be due to the remote suppression on metabolism by the interruption of the cortico-subcortical circuit, which connects the anterior thalamic nucleus and various cortical areas. The executive dysfunction and dysnomia may be caused by the left dorsolateral frontal dysfunction of the thalamo-cortical circuit. Anterograde amnesia with storage deficit may be caused by the disruption of mamillothalamic tract

  10. Stereoselectivity of presynaptic autoreceptors modulating dopamine release

    Energy Technology Data Exchange (ETDEWEB)

    Arbilla, S.; Langer, S.Z. (Department of Biology, Laboratoires d' Etudes et de Recherches Synthelabo, Paris, France)

    1981-12-17

    The effects of the (R)- and (S)-enantiomers of sulpiride and butaclamol were studied on the spontaneous and field stimulation-evoked release of total radioactivity from slices of rabbit caudate nucleus prelabelled with (/sup 3/H)dopamine. (S)-Sulpiride in concentrations ranging from 0.01-1..mu..M enhanced the electrically evoked release of (/sup 3/H)dopamine while (R)-sulpiride was 10 times less potent than (S)-sulpiride. Exposure to (S)-butaclamol (0.1-1 ..mu..M) but not to (R)-butaclamol (0.1-10..mu..M) enhanced the field-stimulated release of (/sup 3/H)dopamine. The facilitatory effects of (S)- and (R)-sulpiride and (S)-butaclamol on the stimulated release of the labelled neurotransmitter were observed under conditions in which these drugs did not modify the spontaneous outflow of radioactivity. Only the active enantiomers of sulpiride and butaclamol antagonized the inhibition by apomorphine (1..mu..M) of the stimulated release of (/sup 3/H)dopamine. Our results indicate that the presynaptic inhibitory dopamine autoreceptors modulating the stimulation-evoked release of (/sup 3/H)dopamine in the caudate nucleus are, like the classical postsynaptic dopamine receptors, chemically stereoselective.

  11. Renal dopamine receptors in health and hypertension.

    Science.gov (United States)

    Jose, P A; Eisner, G M; Felder, R A

    1998-11-01

    During the past decade, it has become evident that dopamine plays an important role in the regulation of renal function and blood pressure. Dopamine exerts its actions via a class of cell-surface receptors coupled to G-proteins that belong to the rhodopsin family. Dopamine receptors have been classified into two families based on pharmacologic and molecular cloning studies. In mammals, two D1-like receptors that have been cloned, the D1 and D5 receptors (known as D1A and D1B, respectively, in rodents), are linked to stimulation of adenylyl cyclase. Three D2-like receptors that have been cloned (D2, D3, and D4) are linked to inhibition of adenylyl cyclase and Ca2+ channels and stimulation of K+ channels. All the mammalian dopamine receptors, initially cloned from the brain, have been found to be expressed outside the central nervous system, in such sites as the adrenal gland, blood vessels, carotid body, intestines, heart, parathyroid gland, and the kidney and urinary tract. Dopamine receptor subtypes are differentially expressed along the nephron, where they regulate renal hemodynamics and electrolyte and water transport, as well as renin secretion. The ability of renal proximal tubules to produce dopamine and the presence of receptors in these tubules suggest that dopamine can act in an autocrine or paracrine fashion; this action becomes most evident during extracellular fluid volume expansion. This renal autocrine/paracrine function is lost in essential hypertension and in some animal models of genetic hypertension; disruption of the D1 or D3 receptor produces hypertension in mice. In humans with essential hypertension, renal dopamine production in response to sodium loading is often impaired and may contribute to the hypertension. The molecular basis for the dopaminergic dysfunction in hypertension is not known, but may involve an abnormal post-translational modification of the dopamine receptor. PMID:9839770

  12. Endogenous Dopamine Suppresses Initiation of Swimming in Prefeeding Zebrafish Larvae

    OpenAIRE

    Thirumalai, Vatsala; Cline, Hollis T.

    2008-01-01

    Dopamine is a key neuromodulator of locomotory circuits, yet the role that dopamine plays during development of these circuits is less well understood. Here, we describe a suppressive effect of dopamine on swim circuits in larval zebrafish. Zebrafish larvae exhibit marked changes in swimming behavior between 3 days postfertilization (dpf) and 5dpf. We found that swim episodes were fewer and of longer durations at 3 than at 5dpf. At 3dpf, application of dopamine as well as bupropion, a dopamin...

  13. Dopamine: an old target in a new therapy

    OpenAIRE

    Banerjee, Sushanta K

    2015-01-01

    Dopamine, a molecule of joy and emotions, plays vital role in regulation cancer growth and tumor angiogenesis. Dopamine secrets from neural cells in brain and peripheral cells as well. Peripheral dopamine is associated with tumorigenic events. Recent publication [Sarkar et al. Int. J. Cancer: doi:10.1002/ijc.29414, 2014] suggests that dopamine can be an ideal substitute as an anti-vascular endothelial growth factor A (VEGF-A) agent for the treatment tumor angiogenesis as dopamine is less expe...

  14. Striatal Presynaptic Dopamine in Schizophrenia, Part I: Meta-Analysis of Dopamine Active Transporter (DAT) Density

    OpenAIRE

    Fusar-Poli, Paolo; Meyer-Lindenberg, Andreas

    2012-01-01

    Background: Striatal dopaminergic neurotransmission has been postulated to be fundamental to the emergence of key symptoms of schizophrenia, such as psychotic symptoms, and is targeted by currently available dopaminergic drugs. A specific marker of the integrity of presynaptic dopamine neurons in the striatum, the density of striatal dopamine terminals, can be quantified through molecular neuroimaging of the dopamine active transporter (DAT). However, the currently available results using thi...

  15. Anterior thalamic nuclei lesions and recovery of function: Relevance to cognitive thalamus.

    Science.gov (United States)

    Dalrymple-Alford, John C; Harland, Bruce; Loukavenko, Elena A; Perry, Brook; Mercer, Stephanie; Collings, David A; Ulrich, Katharina; Abraham, Wickliffe C; McNaughton, Neil; Wolff, Mathieu

    2015-07-01

    Injury to the anterior thalamic nuclei (ATN) and their neural connections is the most consistent neuropathology associated with diencephalic amnesia. ATN lesions in rats produce memory impairments that support a key role for this region within an extended hippocampal system of complex overlapping neural connections. Environmental enrichment is a therapeutic tool that produces substantial, although incomplete, recovery of memory function after ATN lesions, even after the lesion-induced deficit has become established. Similarly, the neurotrophic agent cerebrolysin, also counters the negative effects of ATN lesions. ATN lesions substantially reduce c-Fos expression and spine density in the retrosplenial cortex, and reduce spine density on CA1 neurons; only the latter is reversed by enrichment. We discuss the implications of this evidence for the cognitive thalamus, with a proposal that there are genuine interactions among different but allied thalamo-cortical systems that go beyond a simple summation of their separate effects. PMID:25637779

  16. Bilateral symmetrical basal ganglia and thalamic lesions in children: an update (2015)

    Energy Technology Data Exchange (ETDEWEB)

    Zuccoli, Giulio [Children' s Hospital of Pittsburgh of UPMC, Section of Neuroradiology, Pittsburgh, PA (United States); Yannes, Michael Paul [University of Pittsburgh School of Medicine, Department of Radiology, Pittsburgh, PA (United States); Nardone, Raffaele [Paracelsus Medical University, Department of Neurology, Christian Doppler Klinik, Salzburg (Austria); Bailey, Ariel [West Virginia University, Department of Radiology, Morgantown, WV (United States); Goldstein, Amy [Children' s Hospital of Pittsburgh of UPMC, Department of Neurology, Section of Metabolic Disorders and Neurogenetics, Pittsburgh, PA (United States)

    2015-10-15

    In children, many inherited or acquired neurological disorders may cause bilateral symmetrical signal intensity alterations in the basal ganglia and thalami. A literature review was aimed at assisting neuroradiologists, neurologists, infectious diseases specialists, and pediatricians to provide further understanding into the clinical and neuroimaging features in pediatric patients presenting with bilateral symmetrical basal ganglia and thalamic lesions on magnetic resonance imaging (MRI). We discuss hypoxic-ischemic, toxic, infectious, immune-mediated, mitochondrial, metabolic, and neurodegenerative disorders affecting the basal ganglia and thalami. Recognition and correct evaluation of basal ganglia abnormalities, together with a proper neurological examination and laboratory findings, may enable the identification of each of these clinical entities and lead to earlier diagnosis. (orig.)

  17. Thalamic functional connectivity predicts seizure laterality in individual TLE patients: Application of a biomarker development strategy

    Directory of Open Access Journals (Sweden)

    Daniel S. Barron

    2015-01-01

    No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons. Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses.

  18. Stereological analysis of the mediodorsal thalamic nucleus in schizophrenia: volume, neuron number, and cell types

    DEFF Research Database (Denmark)

    Dorph-Petersen, Karl-Anton; Pierri, Joseph N; Sun, Zhuoxin;

    2004-01-01

    The mediodorsal thalamic nucleus (MD) is the principal relay nucleus for the prefrontal cortex, a brain region thought to be dysfunctional in schizophrenia. Several, but not all, postmortem studies of the MD in schizophrenia have reported decreased volume and total neuronal number. However, it is...... differences were observed between the two groups of monkeys. Thus, these findings do not support the hypothesis that the MD is a locus of pathology in schizophrenia, although they cannot rule out important functional or structural changes in parameters not measured. Like other studies, this investigation is...... subject to the limitations involved in sampling from a heterogeneous population emphasizing the need to continue to improve the application of robust, unbiased techniques to quantitative studies of this complex brain disorder. Udgivelsesdato: 2004-May-10...

  19. Bilateral symmetrical basal ganglia and thalamic lesions in children: an update (2015)

    International Nuclear Information System (INIS)

    In children, many inherited or acquired neurological disorders may cause bilateral symmetrical signal intensity alterations in the basal ganglia and thalami. A literature review was aimed at assisting neuroradiologists, neurologists, infectious diseases specialists, and pediatricians to provide further understanding into the clinical and neuroimaging features in pediatric patients presenting with bilateral symmetrical basal ganglia and thalamic lesions on magnetic resonance imaging (MRI). We discuss hypoxic-ischemic, toxic, infectious, immune-mediated, mitochondrial, metabolic, and neurodegenerative disorders affecting the basal ganglia and thalami. Recognition and correct evaluation of basal ganglia abnormalities, together with a proper neurological examination and laboratory findings, may enable the identification of each of these clinical entities and lead to earlier diagnosis. (orig.)

  20. Thalamic metabolic abnormalities in patients with Huntington's disease measured by magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Casseb, R.F.; Castellano, G., E-mail: gabriela@ifi.unicamp.br [Cooperacao Interinstitucional de Apoio a Pesquisas sobre o Cerebro (Programa CInAPCe), Sao Paulo, SP (Brazil); Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Fisica Gleb Wataghin. Dept. de Raios Cosmicos e Cronologia; D' Abreu, A.; Cendes, F. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Dept. de Neurologia. Lab. de Neuroimagem; Cooperacao Interinstitucional de Apoio a Pesquisas sobre o Cerebro (Programa CInAPCe), Sao Paulo, SP (Brazil); Ruocco, H.H. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Ciencias Medicas. Dept. de Neurologia. Lab. de Neuroimagem; Lopes-Cendes, I., E-mail: seixas.fk@gmail.com [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Ciencias Medicas. Dept. de Genetica Medica; Cooperacao Interinstitucional de Apoio a Pesquisas sobre o Cerebro (Programa CInAPCe), Sao Paulo, SP (Brazil)

    2013-08-15

    Huntington's disease (HD) is a neurologic disorder that is not completely understood; its fundamental physiological mechanisms and chemical effects remain somewhat unclear. Among these uncertainties, we can highlight information about the concentrations of brain metabolites, which have been widely discussed. Concentration differences in affected, compared to healthy, individuals could lead to the development of useful tools for evaluating the progression of disease, or to the advance of investigations of different/alternative treatments. The aim of this study was to compare the thalamic concentration of metabolites in HD patients and healthy individuals using magnetic resonance spectroscopy. We used a 2.0-Tesla magnetic field, repetition time of 1500 ms, and echo time of 135 ms. Spectra from 40 adult HD patients and 26 control subjects were compared. Quantitative analysis was performed using the LCModel method. There were statistically significant differences between HD patients and controls in the concentrations of N-acetylaspartate+N-acetylaspartylglutamate (NAA+NAAG; t-test, P,0.001), and glycerophosphocholine+phosphocholine (GPC+PCh; t-test, P=0.001) relative to creatine+phosphocreatine (Cr+PCr). The NAA+NAAG/Cr+PCr ratio was decreased by 9% and GPC+PCh/Cr+PCr increased by 17% in patients compared with controls. There were no correlations between the concentration ratios and clinical features. Although these results could be caused by T1 and T2 changes, rather than variations in metabolite concentrations given the short repetition time and long echo time values used, our findings point to thalamic dysfunction, corroborating prior evidence. (author)

  1. Thalamic metabolic abnormalities in patients with Huntington's disease measured by magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Huntington's disease (HD) is a neurologic disorder that is not completely understood; its fundamental physiological mechanisms and chemical effects remain somewhat unclear. Among these uncertainties, we can highlight information about the concentrations of brain metabolites, which have been widely discussed. Concentration differences in affected, compared to healthy, individuals could lead to the development of useful tools for evaluating the progression of disease, or to the advance of investigations of different/alternative treatments. The aim of this study was to compare the thalamic concentration of metabolites in HD patients and healthy individuals using magnetic resonance spectroscopy. We used a 2.0-Tesla magnetic field, repetition time of 1500 ms, and echo time of 135 ms. Spectra from 40 adult HD patients and 26 control subjects were compared. Quantitative analysis was performed using the LCModel method. There were statistically significant differences between HD patients and controls in the concentrations of N-acetylaspartate+N-acetylaspartylglutamate (NAA+NAAG; t-test, P,0.001), and glycerophosphocholine+phosphocholine (GPC+PCh; t-test, P=0.001) relative to creatine+phosphocreatine (Cr+PCr). The NAA+NAAG/Cr+PCr ratio was decreased by 9% and GPC+PCh/Cr+PCr increased by 17% in patients compared with controls. There were no correlations between the concentration ratios and clinical features. Although these results could be caused by T1 and T2 changes, rather than variations in metabolite concentrations given the short repetition time and long echo time values used, our findings point to thalamic dysfunction, corroborating prior evidence. (author)

  2. Strategic lesions in the anterior thalamic radiation and apathy in early Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Mario Torso

    Full Text Available Behavioural disorders and psychological symptoms of Dementia (BPSD are commonly observed in Alzheimer's disease (AD, and strongly contribute to increasing patients' disability. Using voxel-lesion-symptom mapping (VLSM, we investigated the impact of white matter lesions (WMLs on the severity of BPSD in patients with amnestic mild cognitive impairment (a-MCI.Thirty-one a-MCI patients (with a conversion rate to AD of 32% at 2 year follow-up and 26 healthy controls underwent magnetic resonance imaging (MRI examination at 3T, including T2-weighted and fluid-attenuated-inversion-recovery images, and T1-weighted volumes. In the patient group, BPSD was assessed using the Neuropsychiatric Inventory-12. After quantitative definition of WMLs, their distribution was investigated, without an a priori anatomical hypothesis, against patients' behavioural symptoms. Unbiased regional grey matter volumetrics was also used to assess the contribution of grey matter atrophy to BPSD.Apathy, irritability, depression/dysphoria, anxiety and agitation were shown to be the most common symptoms in the patient sample. Despite a more widespread anatomical distribution, a-MCI patients did not differ from controls in WML volumes. VLSM revealed a strict association between the presence of lesions in the anterior thalamic radiations (ATRs and the severity of apathy. Regional grey matter atrophy did not account for any BPSD.This study indicates that damage to the ATRs is strategic for the occurrence of apathy in patients with a-MCI. Disconnection between the prefrontal cortex and the mediodorsal and anterior thalamic nuclei might represent the pathophysiological substrate for apathy, which is one of the most common psychopathological symptoms observed in dementia.

  3. Two distinct subpopulations of neurons in the thalamic intergeniculate leaflet identified by subthreshold currents.

    Science.gov (United States)

    Chrobok, Lukasz; Palus, Katarzyna; Lewandowski, Marian Henryk

    2016-08-01

    The intergeniculate leaflet (IGL) is a flat retinorecipient thalamic structure implicated in orchestrating circadian rhythm, historically considered to be a subdivision of the neighboring ventrolateral geniculate nucleus (VLG). IGL consists of two main neuronal subpopulations: enkephalinergic and neuropeptide Y (NPY)-synthesizing cells. These cell types have different functions, connectivity and firing pattern in vivo, which suggest that they have different membrane currents to support their functional differences. We therefore performed patch-clamp experiments combined with immunohistochemical staining to clarify possible differences in the subthreshold currents of IGL neurons. Our results suggest that IGL neurons can be divided into two subpopulations based on two ionic currents. A T-type calcium current (IT) was identified in neurons that do not synthesise NPY, whereas all NPY-positive neurons were found to express a marked A-type potassium current (IA). Due to the fact that the clear electrophysiological discriminants between IGL and VLG are lacking, we decided to compare the amplitudes of the identified currents between those two structures. Our data suggest that VLG neurons can be characterized by a high amplitude IT and a low IA. Finally, we compared both currents with WAG/Rij rats, a well-established model of absence epilepsy, with co-occurring retinal pathologies, sleep-onset disturbances, and seizures exhibiting circadian rhythmicity. Data presented in this study uncovered pathologies in the IT exhibiting neurons of the IGL and VLG. In conclusion, the data presented here suggest that different subthreshold current expression supports the functional differences of thalamic nuclei. Those differences are promising for possible pharmacological manipulations of specified cell types in pathophysiologies including absence epilepsy. PMID:27208616

  4. Comparison of the vasodilator action of dopamine and dopamine agonists in the renal and coronary beds of the dog.

    OpenAIRE

    Lang, W. J.; Woodman, O. L.

    1982-01-01

    1 The effects of dopamine and the dopamine receptor agonists, SK&F 38393 and bromocriptine, on renal and coronary blood flow in the anaesthetized dog were examined. Dopamine was found to dilate both vascular beds, whereas SK&F 38393 increased renal blood flow but did not have any dilator activity in the coronary vasculature. Bromocriptine did not cause vasodilatation in either vascular bed. 2 The vasodilator responses to dopamine and SK&F 38393 were significantly reduced by the dopamine recep...

  5. Diagnosing dopamine-responsive dystonias.

    Science.gov (United States)

    Malek, N; Fletcher, N; Newman, E

    2015-10-01

    The clinical spectrum of dopamine-responsive dystonias (DRDs) has expanded over the last decade to comprise several distinct disorders. At the milder end of the clinical spectrum is the autosomal-dominant guanosine triphosphate cyclohydrolase deficiency syndrome (GTPCH-DRD), and at the more severe end is the much less common autosomal recessive tyrosine hydroxylase deficiency syndrome (TH-DRD), with intermediate forms in between. Understanding the pathophysiology of DRDs can help in their optimal diagnosis and management. These are conditions with the potential to be either underdiagnosed when not considered or overdiagnosed if there is an equivocal L-dopa (levo-3,4-dihydroxyphenylalanine) response. In this article, we discuss the clinical phenotypes of these disorders, and we outline how investigations can help in confirming the diagnosis. PMID:26045581

  6. Turning skin into dopamine neurons

    Institute of Scientific and Technical Information of China (English)

    Malin Parmar; Johan Jakobsson

    2011-01-01

    The possibility to generate neurons from fibroblasts became a reality with the development of iPS technology a few years ago.By reprogramming somatic cells using transcription factor (TF) overexpression,it is possible to generate pluripotent stem cells that then can be differentiated into any somatic cell type including various subtypes of neurons.This raises the possibility of using donor-matched or even patientspecific cells for cell therapy of neurological disorders such as Parkinson's disease (PD),Huntington's disease and stroke.Supporting this idea,dopamine neurons,which are the cells dying in PD,derived from human iPS cells have been demonstrated to survive transplantation and reverse motor symptoms in animal models of PD [1].

  7. Visualization and quantification of dopamine

    International Nuclear Information System (INIS)

    Spiperone is a potent antagonist of dopamine D2 receptors in the brain. 3-N-[11C] methylspiperone (11C-NMSP), a spiperone derivative, was synthesized by N-alkylation of spiperone with [11C] methyliodide for the visualization and quantification of dopamine receptors in the brain using PET. Age related decrease of 11C-NMSP binding to the striatum was studied in healthy normal volunteers and the binding capacity was also examined in patients with Parkinson's disease and striatonigral degeneration (SND). After intravenous injection of 11C-NMSP, 5 sequential 2 min scan followed by 16 sequential 5 min scan were performed using a PET system. Region of interests to the striatum, cerebral cortex and cerebellum were outlined in the brain image and were plotted against time. The radioactivity in the striatum, in which much D2 binding site exists, was the highest among the brain and gradually increased with time. On the other hand, that in the cerebellar cortex, in which only non-specific binding site exists, peaked within 10 min, followed by rapid decrease. The ratios between striatum and cerebellum, which correlate with specific binding of 11C-NMSP, increased with time and had a linear relationship against time. Quantification of specific binding was evaluated by taking receptor-ligand association rate constant 'K3' in 3 conpartment model. The constant K3 was evaluated from the slope of the striatum to cerebellum ratio vesus an equivalent time which was calculated by the radioactivity in the cerebellulm. Decrease of K3 value with increase of age was observed. The values in Parkinson's disease were almost the same or slightly higher than those in age-matched control, however, a significant decrease compated to the normal value was observed in SND. The possible explanations for unchange or slight increase in Parkinson's disease and the decrease in SND were discussed. (author)

  8. Dopamine signals mimic reward prediction errors

    OpenAIRE

    Schoenbaum, Geoffrey; Esber, Guillem R; Iordanova, Mihaela D.

    2013-01-01

    Modern theories of associative learning center on a prediction error. A study finds that artificial activation of dopamine neurons can substitute for missing reward prediction errors to rescue blocked learning.

  9. Modeling the dopamine system in vivo

    International Nuclear Information System (INIS)

    Positron Emission Tomography (PET) can be used to measure several steps in the synthesis, binding, and metabolism of dopamine in the normal or abnormal living human brain. Fluorodopa is a PET tracer of DOPA metabolism. Recent evidence suggests that only a fraction of striatal fluorodopamine accumulates in the large, static pool of dopamine. Hence, the accumulation of FDOPA-derived radioactivity in striatum reflects the dopamine turnover of this pool. Labeled L-deprenyl is a PET tracer of monoamine oxidase B. The accumulation in striatum and other regions of the human brain reflects the number of reactive sites on the enzyme. The densities of dopamine-binding neuroreceptors may be calculated from the accumulation of reversibly binding tracers by equilibrium kinetics or from the accumulation of irreversibly binding tracers by transient analysis. The reversible tracers include labeled SCH 23390 and raclopride. An irreversibly binding tracer is N- methylspiperone

  10. Feasibility of Diffusion Tractography for the Reconstruction of Intra-Thalamic and Cerebello-Thalamic Targets for Functional Neurosurgery: A Multi-Vendor Pilot Study in Four Subjects

    Science.gov (United States)

    Jakab, András; Werner, Beat; Piccirelli, Marco; Kovács, Kázmér; Martin, Ernst; Thornton, John S.; Yousry, Tarek; Szekely, Gabor; O‘Gorman Tuura, Ruth

    2016-01-01

    Functional stereotactic neurosurgery by means of deep brain stimulation or ablation provides an effective treatment for movement disorders, but the outcome of surgical interventions depends on the accuracy by which the target structures are reached. The purpose of this pilot study was to evaluate the feasibility of diffusion tensor imaging (DTI) based probabilistic tractography of deep brain structures that are commonly used for pre- and perioperative targeting for functional neurosurgery. Three targets were reconstructed based on their significance as intervention sites or as a no-go area to avoid adverse side effects: the connections propagating from the thalamus to (1) primary and supplementary motor areas, (2) to somatosensory areas and the cerebello-thalamic tract (CTT). We evaluated the overlap of the reconstructed connectivity based targets with corresponding atlas based data, and tested the inter-subject and inter-scanner variability by acquiring repeated DTI from four volunteers, and on three MRI scanners with similar sequence parameters. Compared to a 3D histological atlas of the human thalamus, moderate overlaps of 35-50% were measured between connectivity- and atlas based volumes, while the minimal distance between the centerpoints of atlas and connectivity targets was 2.5 mm. The variability caused by the MRI scanner was similar to the inter-subject variability, except for connections with the postcentral gyrus where it was higher. While CTT resolved the anatomically correct trajectory of the tract individually, high volumetric variability was found across subjects and between scanners. DTI can be applied in the clinical, preoperative setting to reconstruct the CTT and to localize subdivisions within the lateral thalamus. In our pilot study, such subdivisions moderately matched the borders of the ventrolateral-posteroventral (VLpv) nucleus and the ventral-posterolateral (VPL) nucleus. Limitations of the currently used standard DTI protocols were

  11. Ionization box type radiation detector

    International Nuclear Information System (INIS)

    An ionization box for monitoring radiation rays, a first amplification circuit of a multi-stage amplification circuit employing a MOS type FET as an initial stage amplification device, a second amplification circuit employing a junction type FET as an initial stage amplification device, a first change-over switch for switching ionization current depending on input signals, a second change-over switch for switching output signals, and a signal level discrimination circuit are constituted integrally. When radiation dose rate is low, the ionization current is inputted to the first amplification circuit and outputted as a radiation ray monitor signal and, when the radiation dose rate is increased to higher than a predetermined value, the ionization current is inputted to the second amplification circuit and outputted as a radiation ray monitor signal. That is, monitoring accuracy is high when the ionization current is low since the MOS type FET of high input impedance is used. If the ionization current is higher than a predetermined value, there is no worry that the detection becomes impossible since the junction type FET having less worry of causing characteristic change due to high radiation dose rate is used. Accordingly, ionization box type monitor at a high monitoring reliability can be obtained. (N.H.)

  12. F-box proteins in flowering plants

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In eukaryotes, the ubiquitin-mediated protein degradation pathway has been shown to control several key biological processes such as cell division, development, metabolism and immune response. F-box proteins, as a part of SCF (Skp1-Cullin (or Cdc53)-F-box) complex, functioned by interacting with substrate proteins, leading to their subsequent degradation by the 26S proteasome. To date, several F-box proteins identified in Arabidopsis and Antirrhinum have been shown to play important roles in auxin signal transduction, floral organ formation, flowering and leaf senescence. Arabidopsis genome sequence analysis revealed that it encodes over 1000 predicted F-box proteins accounting for about 5% of total predicted proteins. These results indicate that the ubiquitin-mediated protein degradation involving the F-box proteins is an important mechanism controlling plant gene expression. Here, we review the known F-box proteins and their functionsin flowering plants.

  13. Understanding Recommender Dynamics driving Box Office Revenues

    CERN Document Server

    Yeung, C H; Jin, C -H

    2010-01-01

    We introduce a simple model to investigate the underlying dynamics driving movie box office. Without an explicit reliance on time, the box office of movies evolves naturally by movie-movie competition through reviews listed on a centralized recommender system. A simple mean-field approximation is employed which assumes an average interaction between the competing movies, and describes the interesting box office dynamics. Box office hits are found for movies with quality beyond a critical value, leading to booms in gross box office. Such critical value is dependent on the reviewing behaviors, intention of movie goers for new movies, and the quality of the peer competing movies. Finally we compare our analytical results with simulations and real system and obtain qualitative agreements, suggesting the present model in describing the fundamental dynamics of box office.

  14. Electrophysiology and Pharmacology of the Corticothalamic Input to Lateral Thalamic Nuclei: an Intracellular Study in the Cat.

    Science.gov (United States)

    Deschêenes, Martin; Hu, Bin

    1990-02-01

    Though most experimental evidence indicates that the corticothalamic (CT) pathway would exert a direct excitatory action on thalamic relay neurons, the electrophysiological features of this excitation have never been clearly described. A methodological problem in previous electrophysiological studies was that direct corticofugal effects on relay cells could not be separated from those mediated by collateral activation of reticular thalamic neurons. In the present study, the reticular complex was lesioned by kainic acid and the CT response of relay neurons of the ventral lateral nucleus was recorded intracellularly in cats under pentobarbital or urethane anaesthesia. Following reticular thalamic lesions, a prominent depolarization was triggered in thalamic relay cells by stimulation of the CT pathway. This depolarization strongly drove spike discharges, and its amplitude augmented when the stimulation rate exceeded 2 Hz. Tetanizing the CT input with short trains (100 - 200 Hz for 200 - 300 ms) produced a similar augmentation to test volleys for 15 - 30 s after the tetanos. The CT excitation and its frequency-dependent augmentation were depressed by ketamine injection or by local application of N-methyl-D-aspartate (NMDA) antagonists. The augmenting phenomenon appeared strictly homosynaptic. For instance, it did not appear during repetitive stimulation of the cerebellar input, nor did the CT input potentiate subthreshold synaptic potentials of cerebellar origin during a conditioning procedure. Conversely, the cerebellar excitation was depressed when it occurred during the CT depolarization. It is concluded that the direct synaptic responses induced by CT fibres in relay neurons are mediated at least partly by the activation of NMDA receptors. Moreover, the marked non-linear additivity of cerebellar and CT synaptic potentials raises questions concerning the presumed improvement of thalamic transmission of peripheral informations ensured by the CT input. Instead, both

  15. Metabolism of N-acylated-dopamine.

    Directory of Open Access Journals (Sweden)

    Dominika Zajac

    Full Text Available N-oleoyl-dopamine (OLDA is a novel lipid derivative of dopamine. Its biological action includes the interaction with dopamine and the transient receptor potential vanilloid (TRPV1 receptors. It seems to be synthesized in a dopamine-like manner, but there has been no information on its degradation. The aim of the study was, therefore, to determine whether OLDA metabolism proceeds the way dopamine proper does. We addressed the issue by examining the occurrence of O-methylation of exogenously supplemented OLDA via catechol-O-methyltransferase (COMT under in vitro, ex vivo, and in vivo conditions using rat brain tissue. The results show that OLDA was methylated by COMT in all conditions studied, yielding the O-methylated derivative. The methylation was reversed by tolcapone, a potent COMT inhibitor, in a dose-dependent manner. We conclude that OLDA enters the metabolic pathway of dopamine. Methylation of OLDA may enhance its bioactive properties, such as the ability to interact with TRPV1 receptors.

  16. Dopamine versus noradrenaline in septic shock

    Directory of Open Access Journals (Sweden)

    Bo Xu

    2011-10-01

    Full Text Available BackgroundThe ‘Surviving Sepsis’ Campaign guidelines recommend theuse of dopamine or noradrenaline as the first vasopressor inseptic shock. However, information that guides clinicians inchoosing between dopamine and noradrenaline as the firstvasopressor in patients with septic shock is limited.ObjectiveThis article presents a review of the literature regarding theuse of dopamine versus noradrenaline in patients with septicshock.ResultsTwo randomised controlled trials (RCT and two largeprospective cohort studies were analysed. RCT data showeddopamine was associated with increased arrhythmic events.One cohort study found dopamine was associated with higher30-day mortality. The other cohort study found noradrenalinewas associated with higher 28-day mortality.DiscussionData on the use of dopamine versus noradrenaline in patientswith septic shock is limited. Following the recent SOAP IIstudy, there is now strong evidence that the use of dopaminein septic shock is associated with significantly morecardiovascular adverse events, compared tonoradrenaline.ConclusionNoradrenaline should be used as the initial vasopressor inseptic shock to avoid the arrhythmic events associatedwith dopamine.

  17. Metod of black box and their us

    OpenAIRE

    Novotný, Martin

    2013-01-01

    This thesis on a topic "black-box method and its use" deals with the description of the method of solving problematic tasks as a black box and its use in teaching. Using the theory of systems and cybernetics disciplines, especially cybernetic-pedagogy attempts to describe this method so that it is as efficient as possible and to maximize the benefits for students. Besides, the implementation of selected black box that will be suitable and used for teaching subjects electrotechnics, automatiza...

  18. Inhibitory effects of microinjection of morphine into thalamic nucleus submedius on ipsilateral paw bee venom-induced inflammatory pain in the rat

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective To examine whether microinjection of morphine into the rat thalamic nucleus submedius (Sm) could depress the bee venom (BV)-induced nociceptive behaviours. Methods In inflammatory pain model induced by BV subcutaneous injection into rat unilateral hind paw,the inhibitory effects of morphine microinjection into thalamic nucleus submedius (Sm) on the spontaneous nociceptive behavior,heat hyperalgesia and tactile allodynia,and the influence of naloxone on the morphine effects were observed in the rat...

  19. Repackaging SRS Black Box TRU Waste

    International Nuclear Information System (INIS)

    Historically, large items of TRU Waste, which were too large to be packaged in drums for disposal have been packaged in various sizes of custom made plywood boxes at the Savannah River Site (SRS), for many years. These boxes were subsequently packaged into large steel ''Black Boxes'' for storage at SRS, pending availability of Characterization and Certification capability, to facilitate disposal of larger items of TRU Waste. There are approximately 107 Black Boxes in inventory at SRS, each measuring some 18' x 12' x 7', and weighing up to 45,000 lbs. These Black Boxes have been stored since the early 1980s. The project to repackage this waste into Standard Large Boxes (SLBs), Standard Waste Boxes (SWB) and Ten Drum Overpacks (TDOP), for subsequent characterization and WIPP disposal, commenced in FY04. To date, 10 Black Boxes have been repackaged, resulting in 40 SLB-2's, and 37 B25 overpack boxes, these B25's will be overpacked in SLB-2's prior to shipping to WIPP. This paper will describe experience to date from this project

  20. Interchangeable breech lock for glove boxes

    Energy Technology Data Exchange (ETDEWEB)

    Lemonds, David Preston

    2015-11-24

    A breech lock for a glove box is provided that may be used to transfer one or more items into the glove box. The breech lock can be interchangeably installed in place of a plug, glove, or other device in a port or opening of a glove box. Features are provided to aid the removal of items from the breech lock by a gloved operator. The breech lock can be reused or, if needed, can be replaced with a plug, glove, or other device at the port or opening of the glove box.

  1. Model Equations: "Black Box" Reconstruction

    Science.gov (United States)

    Bezruchko, Boris P.; Smirnov, Dmitry A.

    Black box reconstruction is both the most difficult and the most tempting modelling problem when any prior information about an appropriate model structure is lacking. An intriguing thing is that a model capable of reproducing an observed behaviour or predicting further evolution should be obtained only from an observed time series, i.e. "from nothing" at first sight. Chances for a success are not large. Even more so, a "good" model would become a valuable tool to characterise an object and understand its dynamics. Lack of prior information causes one to utilise universal model structures, e.g. artificial neural networks, radial basis functions and algebraic polynomials are included in the right-hand sides of dynamical model equations. Such models are often multi-dimensional and involve quite many free parameters.

  2. Lesion of the Centromedian Thalamic Nucleus in MPTP-Treated Monkeys

    OpenAIRE

    Lanciego, J.L. (José Luis); Rodriguez-Oroz, M C; Blesa, F.J. (F.J.); Alvarez-Erviti, L; Guridi, J.; Barroso-Chinea, P. (P.); Smith, Y.; J.A. Obeso

    2008-01-01

    The caudal intralaminar nuclei are a major source of glutamatergic afferents to the basal ganglia. Experiments in the 6-hydroxydopamine rat model have shown that the parafascicular nucleus is overactive and its lesion alleviates basal ganglia neurochemical abnormalities associated with dopamine depletion. Accordingly, removal of this excitatory innervation of the basal ganglia could have a beneficial value in the parkinsonian state. To test this hypothesis, unilateral kainate-induced chemical...

  3. Bleomycin induced flagellate erythema in a patient with thalamic mixed germ cell tumour: Report of a rare adverse effect

    OpenAIRE

    Ahitagni Biswas; Pramod Kumar Julka

    2016-01-01

    Bleomycin induced flagellate dermatitis is an uncommon and unique adverse effect. With the declining use of bleomycin, this complication is becoming increasingly infrequent in day-to-day clinical practice. We herein describe a case of a 13 year old male patient with left thalamic mixed germ cell tumour treated by multimodality approach, who developed flagellate erythema after two cycles of combination chemotherapy with bleomycin, etoposide and cisplatin (BEP). This brief report highlights the...

  4. Thalamic innervation of the direct and indirect basal ganglia pathways in the rat: Ipsi- and contralateral projections

    OpenAIRE

    Castle, M; Aymerich, M.S. (María S.); Sanchez-Escobar, C. (Carlos); N. Gonzalo; Obeso, J. A.; Lanciego, J.L.

    2005-01-01

    The present study describes the thalamic innervation coming from the rat parafascicular nucleus (PF) onto striatal and subthalamic efferent neurons projecting either to the globus pallidus (GP) or to the substantia nigra pars reticulata (SNr) by using a protocol for multiple neuroanatomical tracing. Both striatofugal neurons targeting the ipsilateral SNr (direct pathway) as well as striatal efferent neurons projecting to the ipsilateral GP (indirect pathway) were located within the terminal f...

  5. Cortical-Thalamic Axons are Required for Retinal Ganglion Cell Targeting to the Mouse Dorsal Lateral Geniculate Nucleus

    OpenAIRE

    Shanks, James Alexander

    2015-01-01

    AbstractJames A. ShanksCortical-Thalamic Axons are Required for Retinal Ganglion Cell Targeting to the Mouse Dorsal Lateral Geniculate Nucleus The human brain contains over 85 billion neurons, which make trillions of synapses in a very ordered and stereotypical manner (Williams and Herrup, 1988). The human cerebral cortex, which contains over 20 percent of the total number of neurons within the brain, is responsible for critical functions such as memory, attention, perception, awareness, lan...

  6. High field fMRI reveals thalamocortical integration of segregated cognitive and emotional processing in mediodorsal and intralaminar thalamic nuclei

    Directory of Open Access Journals (Sweden)

    Coraline Danielle Metzger

    2010-11-01

    Full Text Available Thalamocortical loops, connecting functionally segregated, higher order cortical regions and basal ganglia, have been proposed not only for well described motor and sensory regions, but also for limbic and prefrontal areas relevant for affective and cognitive processes. These functions are, however, more specific to humans, rendering most invasive neuroanatomical approaches impossible and interspecies translations difficult. In contrast, non invasive imaging of functional neuroanatomy using fMRI allows for the development of elaborate task paradigms capable of testing the specific functionalities proposed for these circuits. Until recently, spatial resolution largely limited the anatomical definition of functional clusters at the level of distinct thalamic nuclei. Since their anatomical distinction seems crucial not only for the segregation of cognitive and limbic loops but also for the detection of their functional interaction during cognitive-emotional integration, we applied high resolution fMRI on 7 Tesla.Using an event related design, we could isolate thalamic effects for preceding attention as well as experience of erotic stimuli. We could demonstrate specific thalamic effects of general emotional arousal in mediodorsal nucleus and effects specific to preceding attention and expectancy in intralaminar centromedian/parafascicular complex (CM/PF. These thalamic effects were paralleled by specific coactivations in the head of caudate nucleus as well as segregated portions of rostral or caudal cingulate cortex and anterior insula supporting distinct thalamo-striato-cortical loops. In addition to predescribed effects of sexual arousal in hypothalamus and ventral striatum, high resolution fMRI could extent this network to paraventricular thalamus encompassing laterodorsal and parataenial nuclei. We could lend evidence to segregated subcortical loops which integrate cognitive and emotional aspects of basic human behaviour such as sexual

  7. Impaired Macromolecular Protein Pools in Fronto-Striato-Thalamic Circuits in Type 2 Diabetes Revealed by Magnetization Transfer Imaging

    OpenAIRE

    Yang, Shaolin; Ajilore, Olusola; Wu, Minjie; Lamar, Melissa; Kumar, Anand

    2014-01-01

    Previous research has shown that type 2 diabetes mellitus (T2DM) is associated with white matter microstructural changes, cognitive impairment, and decreased resting-state functional connectivity and spontaneous brain activity. This study used magnetization transfer imaging to examine, for the first time, the integrity of macromolecular protein pools in fronto-striato-thalamic circuits and its clinical and cognitive correlates in patients with T2DM. T2DM patients without mood disorders (n = 2...

  8. Genetic disruption of dopamine production results in pituitary adenomas and severe prolactinemia

    Science.gov (United States)

    Dopamine release from tuberoinfundibular dopamine neurons into the median eminence activates dopamine-D2 receptors in the pituitary gland where it inhibits lactotroph function. We have previously described genetic dopamine-deficient mouse models which lack the ability to synthesize dopamine. Because...

  9. Addiction: Beyond dopamine reward circuitry

    Energy Technology Data Exchange (ETDEWEB)

    Volkow, N.D.; Wang, G.; Volkow, N.D.; Wang, G.-J.; Fowler, J.S.; Tomasi, D.; Telang, F.

    2011-09-13

    Dopamine (DA) is considered crucial for the rewarding effects of drugs of abuse, but its role in addiction is much less clear. This review focuses on studies that used PET to characterize the brain DA system in addicted subjects. These studies have corroborated in humans the relevance of drug-induced fast DA increases in striatum [including nucleus accumbens (NAc)] in their rewarding effects but have unexpectedly shown that in addicted subjects, drug-induced DA increases (as well as their subjective reinforcing effects) are markedly blunted compared with controls. In contrast, addicted subjects show significant DA increases in striatum in response to drug-conditioned cues that are associated with self-reports of drug craving and appear to be of a greater magnitude than the DA responses to the drug. We postulate that the discrepancy between the expectation for the drug effects (conditioned responses) and the blunted pharmacological effects maintains drug taking in an attempt to achieve the expected reward. Also, whether tested during early or protracted withdrawal, addicted subjects show lower levels of D2 receptors in striatum (including NAc), which are associated with decreases in baseline activity in frontal brain regions implicated in salience attribution (orbitofrontal cortex) and inhibitory control (anterior cingulate gyrus), whose disruption results in compulsivity and impulsivity. These results point to an imbalance between dopaminergic circuits that underlie reward and conditioning and those that underlie executive function (emotional control and decision making), which we postulate contributes to the compulsive drug use and loss of control in addiction.

  10. Imaging dopamine transmission in schizophrenia

    International Nuclear Information System (INIS)

    Over the last ten years, several positron emission tomography (PET) and single photon computerized tomography (SPECT) studies of the dopamine (DA) system in patients with schizophrenia were performed to test the hypothesis that DA hyperactivity is associated with this illness. In this paper are reviewed the results of fifteen brain imaging studies comparing indices of DA function in drug naive or drug free patients with schizophrenia and healthy controls: thirteen studies included measurements of Da D2 receptor density, two studies compared amphetamine-induced DA release, and two studies measured DOPA decarboxylase activity, an enzyme involved in DA synthesis. It was conducted a meta-analysis of the studies measuring D2 receptor density parameters, under the assumption that all tracers labeled the same population of D2 receptors. This analysis revealed that, compared to healthy controls, patients with schizophrenia present a significant but mild elevation of D2 receptor density parameters and a significant larger variability of these indices. It was found no statistical evidence that studies performed with radiolabeled butyrophenones detected a larger increase in D2 receptor density parameters than studies performed with other radioligands, such as benzamides. Studies of presynaptic activity revealed an increase in DA transmission response to amphetamine challenge, and an increase in DOPA decarboxylase activity. Together, these data are compatible with both pre- and post-synaptic alterations of DA transmission in schizophrenia. Future studies should aim at a better characterization of these alterations, and at defining their role in the pathophysiology of the illness

  11. Addiction: Beyond dopamine reward circuitry

    International Nuclear Information System (INIS)

    Dopamine (DA) is considered crucial for the rewarding effects of drugs of abuse, but its role in addiction is much less clear. This review focuses on studies that used PET to characterize the brain DA system in addicted subjects. These studies have corroborated in humans the relevance of drug-induced fast DA increases in striatum [including nucleus accumbens (NAc)] in their rewarding effects but have unexpectedly shown that in addicted subjects, drug-induced DA increases (as well as their subjective reinforcing effects) are markedly blunted compared with controls. In contrast, addicted subjects show significant DA increases in striatum in response to drug-conditioned cues that are associated with self-reports of drug craving and appear to be of a greater magnitude than the DA responses to the drug. We postulate that the discrepancy between the expectation for the drug effects (conditioned responses) and the blunted pharmacological effects maintains drug taking in an attempt to achieve the expected reward. Also, whether tested during early or protracted withdrawal, addicted subjects show lower levels of D2 receptors in striatum (including NAc), which are associated with decreases in baseline activity in frontal brain regions implicated in salience attribution (orbitofrontal cortex) and inhibitory control (anterior cingulate gyrus), whose disruption results in compulsivity and impulsivity. These results point to an imbalance between dopaminergic circuits that underlie reward and conditioning and those that underlie executive function (emotional control and decision making), which we postulate contributes to the compulsive drug use and loss of control in addiction.

  12. Dopamine, behavioral economics, and effort

    Directory of Open Access Journals (Sweden)

    John D Salamone

    2009-09-01

    Full Text Available Abstract. There are numerous problems with the hypothesis that brain dopamine (DA systems, particularly in the nucleus accumbens, directly mediate the rewarding or primary motivational characteristics of natural stimuli such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on hedonia and primary reward yielding to other concepts and lines of inquiry. The present review is focused upon the involvement of nucleus accumbens DA in behavioral activation and effort-related processes. Viewed from the framework of behavioral economics, the effects of accumbens DA depletions and antagonism on food-reinforced behavior are highly dependent upon the work requirements of the instrumental task, and DA depleted rats are more sensitive to increases in response costs (i.e., ratio requirements. Moreover, interference with accumbens DA transmission exerts a powerful influence over effort-related choice behavior. Rats with accumbens DA depletions or antagonism reallocate their instrumental behavior away from food-reinforced tasks that have high response requirements, and instead these rats select a less-effortful type of food-seeking behavior. Nucleus accumbens DA and adenosine interact in the regulation of effort-related functions, and other brain structures (anterior cingulate cortex, amygdala, ventral pallidum also are involved. Studies of the brain systems regulating effort-based processes may have implications for understanding drug abuse, as well as energy-related disorders such as psychomotor slowing, fatigue or anergia in depression and other neurological disorders.

  13. Dopamine, behavioral economics, and effort.

    Science.gov (United States)

    Salamone, John D; Correa, Merce; Farrar, Andrew M; Nunes, Eric J; Pardo, Marta

    2009-01-01

    There are numerous problems with the hypothesis that brain dopamine (DA) systems, particularly in the nucleus accumbens, directly mediate the rewarding or primary motivational characteristics of natural stimuli such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on hedonia and primary reward yielding to other concepts and lines of inquiry. The present review is focused upon the involvement of nucleus accumbens DA in behavioral activation and effort-related processes. Viewed from the framework of behavioral economics, the effects of accumbens DA depletions and antagonism on food-reinforced behavior are highly dependent upon the work requirements of the instrumental task, and DA depleted rats are more sensitive to increases in response costs (i.e., ratio requirements). Moreover, interference with accumbens DA transmission exerts a powerful influence over effort-related choice behavior. Rats with accumbens DA depletions or antagonism reallocate their instrumental behavior away from food-reinforced tasks that have high response requirements, and instead these rats select a less-effortful type of food-seeking behavior. Nucleus accumbens DA and adenosine interact in the regulation of effort-related functions, and other brain structures (anterior cingulate cortex, amygdala, ventral pallidum) also are involved. Studies of the brain systems regulating effort-based processes may have implications for understanding drug abuse, as well as energy-related disorders such as psychomotor slowing, fatigue or anergia in depression and other neurological disorders. PMID:19826615

  14. Unification of box shapes in molecular simulations

    NARCIS (Netherlands)

    Bekker, H.

    1997-01-01

    In molecular simulations with periodic boundary conditions the computational box may have five different shapes: triclinic; the hexagonal prism; two types of dodecahedrons; and the truncated octahedron. In this article, we show that every molecular simulation, formulated in one of these boxes, can b

  15. Black-Box Search by Unbiased Variation

    DEFF Research Database (Denmark)

    Lehre, Per Kristian; Witt, Carsten

    2012-01-01

    The complexity theory for black-box algorithms, introduced by Droste, Jansen, and Wegener (Theory Comput. Syst. 39:525–544, 2006), describes common limits on the efficiency of a broad class of randomised search heuristics. There is an obvious trade-off between the generality of the black-box model...

  16. Cosmetic Foot Surgery: Fashion's Pandora's Box

    Science.gov (United States)

    ... Fashion’s Pandora’s Box? A A A | Print | Share Cosmetic Foot Surgery: Fashion’s Pandora’s Box? Foot and ankle ... extreme and imprudent as it may sound, the cosmetic surgery craze isn't just for faces anymore- ...

  17. Modern biotechnology Panacea or new Pandora's box?

    NARCIS (Netherlands)

    Tramper, J.; Yang Zhu, Yang

    2011-01-01

    According to Greek mythology Pandora was sent down to earth upon the orders of Zeus. She was given a mysterious box which she was not allowed to open. However, Pandora was very curious and when she arrived on earth she couldn?t help taking a peek inside the box. She saw that it was filled with gifts

  18. Box Plots in the Australian Curriculum

    Science.gov (United States)

    Watson, Jane M.

    2012-01-01

    This article compares the definition of "box plot" as used in the "Australian Curriculum: Mathematics" with other definitions used in the education community; describes the difficulties students experience when dealing with box plots; and discusses the elaboration that is necessary to enable teachers to develop the knowledge necessary to use them…

  19. 49 CFR 178.515 - Standards for reconstituted wood boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for reconstituted wood boxes. 178.515... wood boxes. (a) The identification code for a reconstituted wood box is 4F. (b) Construction requirements for reconstituted wood boxes are as follows: (1) The walls of boxes must be made of...

  20. Dopamine-induced apoptosis in human neuronal cells: inhibition by nucleic acides antisense to the dopamine transporter

    International Nuclear Information System (INIS)

    Human neuroblastoma NMB cells take up [3H]dopamine in a selective manner indicating that dopamine transporters are responsible for this uptake. These cells were therefore used as a model to study dopamine neurotoxicity, and to elucidate the role of dopamine transporters in controlling cell death. Treatment with 0.05-0.4 mM dopamine changed cells' morphology within 4 h, accompanied by retraction of processes, shrinkage, apoptosis-like atrophy, accumulation of apoptotic particles, DNA fragmentation and cell death. Cycloheximide inhibited dopamine's effect, suggesting that induction of apoptosis by dopamine was dependent upon protein synthesis. Dopamine cytotoxicity, monitored morphologically by flow cytometric analysis, and by lactate dehydrogenase released, was blocked by cocaine but not by the noradrenaline and serotonin uptake blockers desimipramine and imipramine, respectively. Attempting to inhibit dopamine transport and toxicity in a drug-free and highly selective way, three 18-mer dopamine transporter antisense phosphorothioate oligonucleotides (numbers 1, 2 and 3) and a new plasmid vector expressing the entire rat dopamine transporter complementary DNA in the antisense orientation were prepared and tested. Antisense phosphorothioate oligonucleotide 3 inhibited [3H]dopamine uptake in a time- and dose-dependent manner. Likewise, transient transfection of NMB cells with the plasmid expressing dopamine transporter complementary DNA in the antisense orientation partially blocked [3H]dopamine uptake. Antisense phosphorothioate oligonucleotide 3 also decreased, dose-dependently, the toxic effect of dopamine and 6-hydroxydopamine. Western blot analysis with newly prepared anti-human dopamine transporter antibodies showed that antisense phosphorothioate oligonucleotide 3 decreased the transporter protein level. These studies contribute to better understand the mechanism of dopamine-induced apoptosis and neurotoxicity. (Copyright (c) 1996 Elsevier Science B

  1. Brain May Compensate for Dopamine Neuron Loss Early in Parkinson's

    Science.gov (United States)

    ... More Science News Brain May Compensate for Dopamine Neuron Loss Early in Parkinson’s - May 09 2014 Scientists ... at least 25 percent of the brain’s dopamine neurons already have been lost. So why do symptoms ...

  2. Cerebral vascular effects of hypovolemia and dopamine infusions

    DEFF Research Database (Denmark)

    Holst Hahn, Gitte; Heiring, Christian; Pryds, Ole;

    2012-01-01

    Despite widespread use, effects of volume boluses and dopamine in hypotensive newborn infants remain controversial. We aimed to elucidate if hypovolemia alone impairs cerebral autoregulation (CA) and if dopamine affects cerebral vasculature....

  3. Modeling dopamine system dysfunction in experimental animals

    International Nuclear Information System (INIS)

    Quite a substantial number of human disorders have been associated with a primary or a secondary impairment of one or several of the dopaminergic pathways. Among disorders associated with a primary impairment of dopaminergic transmission are Parkinson's disease, striatonigral degeneration, progressive supranuclear palsy, and possibly schizophrenia. Diseases of secondary dopamine dysfunction are chiefly represented by Huntington's disease in which dopaminergic transmission is being interrupted by progressive loss of the striatal neurons bearing the postsynaptic D1- and D2-dopamine receptors. Central dopaminergic systems have anatomical as well as organizational properties that render them unique by comparison to other neurotransmission systems, making them able to play a pivotal role in the modulation of various important brain functions such as locomotor activity, attention, and some cognitive abilities. These properties of dopamine neurons have obviously several implications in the clinical expression of human disorders involving dopamine neuron dysfunction. In addition, they can greatly influence the clinical/behavioral consequences of experimental lesions in animal models of dopamine dysfunctions

  4. Regionally specific expression of high-voltage-activated calcium channels in thalamic nuclei of epileptic and non-epileptic rats.

    Science.gov (United States)

    Kanyshkova, Tatyana; Ehling, Petra; Cerina, Manuela; Meuth, Patrick; Zobeiri, Mehrnoush; Meuth, Sven G; Pape, Hans-Christian; Budde, Thomas

    2014-07-01

    The polygenic origin of generalized absence epilepsy results in dysfunction of ion channels that allows the switch from physiological asynchronous to pathophysiological highly synchronous network activity. Evidence from rat and mouse models of absence epilepsy indicates that altered Ca(2+) channel activity contributes to cellular and network alterations that lead to seizure activity. Under physiological circumstances, high voltage-activated (HVA) Ca(2+) channels are important in determining the thalamic firing profile. Here, we investigated a possible contribution of HVA channels to the epileptic phenotype using a rodent genetic model of absence epilepsy. In this study, HVA Ca(2+) currents were recorded from neurons of three different thalamic nuclei that are involved in both sensory signal transmission and rhythmic-synchronized activity during epileptic spike-and-wave discharges (SWD), namely the dorsal part of the lateral geniculate nucleus (dLGN), the ventrobasal thalamic complex (VB) and the reticular thalamic nucleus (NRT) of epileptic Wistar Albino Glaxo rats from Rijswijk (WAG/Rij) and non-epileptic August Copenhagen Irish (ACI) rats. HVA Ca(2+) current densities in dLGN neurons were significantly increased in epileptic rats compared with non-epileptic controls while other thalamic regions revealed no differences between the strains. Application of specific channel blockers revealed that the increased current was carried by L-type Ca(2+) channels. Electrophysiological evidence of increased L-type current correlated with up-regulated mRNA and protein expression of a particular L-type channel, namely Cav1.3, in dLGN of epileptic rats. No significant changes were found for other HVA Ca(2+) channels. Moreover, pharmacological inactivation of L-type Ca(2+) channels results in altered firing profiles of thalamocortical relay (TC) neurons from non-epileptic rather than from epileptic rats. While HVA Ca(2+) channels influence tonic and burst firing in ACI and WAG

  5. Phasic dopamine release in appetitive behaviors and drug abuse

    OpenAIRE

    Wanat, Matthew J.; Willuhn, Ingo; Clark, Jeremy J.; Phillips, Paul E.M.

    2009-01-01

    Short phasic bursts of neuronal activity in dopamine neurons produce rapid and transient increases in extracellular dopamine concentrations throughout the mesocorticolimbic system, which are associated with the initiation of goal-directed behaviors. It is well established that acute exposure to many addictive drugs produce increases in tonic dopamine levels that occur on the order of minutes. However, recent studies suggest that abused drugs similarly enhance phasic dopamine release events th...

  6. Impaired spatial working memory after anterior thalamic lesions: recovery with cerebrolysin and enrichment.

    Science.gov (United States)

    Loukavenko, Elena A; Wolff, Mathieu; Poirier, Guillaume L; Dalrymple-Alford, John C

    2016-05-01

    Lesions to the anterior thalamic nuclei (ATN) in rats produce robust spatial memory deficits that reflect their influence as part of an extended hippocampal system. Recovery of spatial working memory after ATN lesions was examined using a 30-day administration of the neurotrophin cerebrolysin and/or an enriched housing environment. As expected, ATN lesions in standard-housed rats given saline produced severely impaired reinforced spatial alternation when compared to standard-housed rats with sham lesions. Both cerebrolysin and enrichment substantially improved this working memory deficit, including accuracy on trials that required attention to distal cues for successful performance. The combination of cerebrolysin and enrichment was more effective than either treatment alone when the delay between successive runs in a trial was increased to 40 s. Compared to the intact rats, ATN lesions in standard-housed groups produced substantial reduction in c-Fos expression in the retrosplenial cortex, which remained low after cerebrolysin and enrichment treatments. Evidence that multiple treatment strategies restore some memory functions in the current lesion model reinforces the prospect for treatments in human diencephalic amnesia. PMID:25725627

  7. The slow oscillation in cortical and thalamic networks: mechanisms and functions

    Directory of Open Access Journals (Sweden)

    Garrett T. Neske

    2016-01-01

    Full Text Available During even the most quiescent behavioral periods, the cortex and thalamus express rich spontaneous activity in the form of slow (<1 Hz, synchronous network state transitions. Throughout this so-called slow oscillation, cortical and thalamic neurons fluctuate between periods of intense synaptic activity (Up states and almost complete silence (Down states. The two decades since the original characterization of the slow oscillation in the cortex and thalamus have seen considerable advances in deciphering the cellular and network mechanisms associated with this pervasive phenomenon. There are, nevertheless, many questions regarding the slow oscillation that await more thorough illumination, particularly the mechanisms by which Up states initiate and terminate, the functional role of the rhythmic activity cycles in unconscious or minimally conscious states, and the precise relation between Up states and the activated states associated with waking behavior. Given the substantial advances in multineuronal recording and imaging methods in both in vivo and in vitro preparations, the time is ripe to take stock of our current understanding of the slow oscillation and pave the way for future investigations of its mechanisms and functions. My aim in this Review is to provide a comprehensive account of the mechanisms and functions of the slow oscillation, and to suggest avenues for further exploration.

  8. Ophthalmoplegic migraine with reversible thalamic ischemia by Tc-99m ethylcysteinate dimer brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Ho; Shin, Dong Jin; Kang, Sung Soo [Gachon Medical School, Gil Medical Center, Inchon (Korea, Republic of)

    1999-07-01

    Two patients presented with ophthalmoplegic migraine (OM) underwent EEG, Brain-MRI, cerebral angiography, and Tc-99m ECD SPECT during an attack. Follow-up SPECT was performed after neurologic symptoms resolved. In both cases, SPECT during an attack of ophthalmoplegia and headache demonstrated a significantly decreased regional cerebral blood flow in the thalamus to the side of ophthalmoplegia, which was normalized on the follow-up SPECT during a symptom free recovery phase (Lesion to Non-lesion thalamic ratio=1.19 to 0.96 and 1.16 to 0.98, respectively). The other roentgenographic and laboratory findings were normal. These findings are suggestive the ischemia in the perforators of PCA results in third nerve palsy because the portion of oculomotor nerve behind the cavernous sinus derives its blood supply from small perforating branches of the basilar and PCA. Matched ictal hypoperfusion of the thalamus to the site of ophthalmoplegic migraine is suggestive of the ischemic neuropathy as an etiology of OM.

  9. Gait balance disorder by thalamic infarction with the disorder of interstitial nucleus of cajal.

    Science.gov (United States)

    Kurosu, A; Hayashi, Y; Wada, K; Nagaoka, M

    2011-01-01

    The interstitial nucleus of Cajal (INC) is thought to play an important role in torsional/vertical eye position and head posture, and disorders of the INC induce abnormal ocular movements and head tilt. Our patients with ocular tilt reactions simultaneously also had disturbances in ambulatory balance, yet no reports address the loss of balance control induced by disorders of the INC. We examined the ambulatory disturbances induced by INC lesion. We experienced three patients with ocular movement disorders and abnormal head tilt due to thalamic infarction. We performed ophthalmic examinations on and checked the balance of them. With funduscopy, abnormal cycloduction was seen in the unaffected side and normal cycloduction was observed in the affected side. Nevertheless, Hess charts showed distortions in the visual image of both eyes. They all had disorders of balance control. We tried to treat them using the Bobath approach for improving their ambulatory balance. With subsequent improvements in balance control it was possible for them to take short walks, but it was difficult to make any improvements in their ocular movement. The INC is related to balance control of ambulation and disorders of the INC induce ambulatory disturbances. Cycloduction was only observed in the unaffected side, but Hess charts showed distortions of the visual image in both eyes. Ambulation was briefly improved, but diplopia persisted in these patients. PMID:21769260

  10. Minimal Hodgkin-Huxley type models for different classes of cortical and thalamic neurons.

    Science.gov (United States)

    Pospischil, Martin; Toledo-Rodriguez, Maria; Monier, Cyril; Piwkowska, Zuzanna; Bal, Thierry; Frégnac, Yves; Markram, Henry; Destexhe, Alain

    2008-11-01

    We review here the development of Hodgkin-Huxley (HH) type models of cerebral cortex and thalamic neurons for network simulations. The intrinsic electrophysiological properties of cortical neurons were analyzed from several preparations, and we selected the four most prominent electrophysiological classes of neurons. These four classes are "fast spiking", "regular spiking", "intrinsically bursting" and "low-threshold spike" cells. For each class, we fit "minimal" HH type models to experimental data. The models contain the minimal set of voltage-dependent currents to account for the data. To obtain models as generic as possible, we used data from different preparations in vivo and in vitro, such as rat somatosensory cortex and thalamus, guinea-pig visual and frontal cortex, ferret visual cortex, cat visual cortex and cat association cortex. For two cell classes, we used automatic fitting procedures applied to several cells, which revealed substantial cell-to-cell variability within each class. The selection of such cellular models constitutes a necessary step towards building network simulations of the thalamocortical system with realistic cellular dynamical properties. PMID:19011929

  11. Corticothalamic Synaptic Noise as a Mechanism for Selective Attention in Thalamic Neurons

    Directory of Open Access Journals (Sweden)

    Sébastien Béhuret

    2015-12-01

    Full Text Available A reason why the thalamus is more than a passive gateway for sensory signals is that two-third of the synapses of thalamocortical neurons are directly or indirectly related to the activity of corticothalamic axons. While the responses of thalamocortical neurons evoked by sensory stimuli are well characterized, with ON- and OFF-center receptive field structures, the prevalence of synaptic noise resulting from neocortical feedback in intracellularly recorded thalamocortical neurons in vivo has attracted little attention. However, in vitro and modeling experiments point to its critical role for the integration of sensory signals. Here we combine our recent findings in a unified framework suggesting the hypothesis that corticothalamic synaptic activity is adapted to modulate the transfer efficiency of thalamocortical neurons during selective attention at three different levels: First, on ionic channels by interacting with intrinsic membrane properties, second at the neuron level by impacting on the input-output gain, and third even more effectively at the cell assembly level by boosting the information transfer of sensory features encoded in thalamic subnetworks. This top-down population control is achieved by tuning the correlations in subthreshold membrane potential fluctuations and is adapted to modulate the transfer of sensory features encoded by assemblies of thalamocortical relay neurons. We thus propose that cortically-controlled (de-correlation of subthreshold noise is an efficient and swift dynamic mechanism for selective attention in the thalamus.

  12. Abnormal EEG Complexity and Functional Connectivity of Brain in Patients with Acute Thalamic Ischemic Stroke

    Science.gov (United States)

    Liu, Shuang; Guo, Jie; Meng, Jiayuan; Wang, Zhijun; Yao, Yang; Yang, Jiajia; Qi, Hongzhi; Ming, Dong

    2016-01-01

    Ischemic thalamus stroke has become a serious cardiovascular and cerebral disease in recent years. To date the existing researches mostly concentrated on the power spectral density (PSD) in several frequency bands. In this paper, we investigated the nonlinear features of EEG and brain functional connectivity in patients with acute thalamic ischemic stroke and healthy subjects. Electroencephalography (EEG) in resting condition with eyes closed was recorded for 12 stroke patients and 11 healthy subjects as control group. Lempel-Ziv complexity (LZC), Sample Entropy (SampEn), and brain network using partial directed coherence (PDC) were calculated for feature extraction. Results showed that patients had increased mean LZC and SampEn than the controls, which implied the stroke group has higher EEG complexity. For the brain network, the stroke group displayed a trend of weaker cortical connectivity, which suggests a functional impairment of information transmission in cortical connections in stroke patients. These findings suggest that nonlinear analysis and brain network could provide essential information for better understanding the brain dysfunction in the stroke and assisting monitoring or prognostication of stroke evolution.

  13. 99mTc-HMPAO SPECT thalamic blood flow study in migraine

    International Nuclear Information System (INIS)

    The changes of blood flow in the thalamic of migraineurs by 99mTc-HMPAO SPECT imaging are investigated. 60 cases with migraine were performed by Novo 810 high-resolution SPECT 30 minutes after injection of 99mTc-HMPAO. The quantitative analysis of SPECT data was based on the irregular ROI% uptake normalized to total slice method. There were significantly increased mean % uptake values in migraine with aura (259.1 +-17.1), and more significantly in those who experienced hemisensory symptoms and hemiparesis during aura (263.8 +- 17.2), compared to that of migraine without aura (249.1 +- 14.9), but there were not statistically significant difference between migraine with only visual disturbance during aura (255.1 +- 16.4) and without aura. The possible explanations for the increased mean % uptake values in migraineurs who experienced hemisensory symptoms and hemiparesis during aura are: (1) the reactive postischemic hyperemia. (2) excepting thalamus, the regional blood flow was decreased. (3) the secondary phenomenon to the various neurogenic and chemical stimuli

  14. Modelling of cortical and thalamic 600 Hz activity by means of oscillatory networks.

    Science.gov (United States)

    Milde, Thomas; Haueisen, Jens; Witte, Herbert; Leistritz, Lutz

    2009-11-01

    The purpose of this study is to investigate information processing in the primary somatosensory system with the help of oscillatory network modelling. Specifically, we consider interactions in the oscillatory 600Hz activity between the thalamus and the cortical Brodmann areas 3b and 1. This type of cortical activity occurs after electrical stimulation of peripheral nerves such as the median nerve. Our measurements consist of simultaneous 31-channel MEG and 32-channel EEG recordings and individual 3D MRI data. We perform source localization by means of a multi-dipole model. The dipole activation time courses are then modelled by a set of coupled oscillators, described by linear second-order ordinary delay differential equations (DDEs). In particular, a new model for the thalamic activity is included in the oscillatory network. The parameters of the DDE system are successfully fitted to the data by a nonlinear evolutionary optimization method. To activate the oscillatory network, an individual input function is used, based on measurements of the propagated stimulation signal at the biceps. A significant feedback from the cortex to the thalamus could be detected by comparing the network modelling with and without feedback connections. Our finding in humans is supported by earlier animal studies. We conclude that this type of rhythmic brain activity can be modelled by oscillatory networks in order to disentangle feed forward and feedback information transfer. PMID:19497365

  15. Thalamic reticular impairment underlies attention deficit in Ptchd1(Y/-) mice.

    Science.gov (United States)

    Wells, Michael F; Wimmer, Ralf D; Schmitt, L Ian; Feng, Guoping; Halassa, Michael M

    2016-04-01

    Developmental disabilities, including attention-deficit hyperactivity disorder (ADHD), intellectual disability (ID), and autism spectrum disorders (ASD), affect one in six children in the USA. Recently, gene mutations in patched domain containing 1 (PTCHD1) have been found in ~1% of patients with ID and ASD. Individuals with PTCHD1 deletion show symptoms of ADHD, sleep disruption, hypotonia, aggression, ASD, and ID. Although PTCHD1 is probably critical for normal development, the connection between its deletion and the ensuing behavioural defects is poorly understood. Here we report that during early post-natal development, mouse Ptchd1 is selectively expressed in the thalamic reticular nucleus (TRN), a group of GABAergic neurons that regulate thalamocortical transmission, sleep rhythms, and attention. Ptchd1 deletion attenuates TRN activity through mechanisms involving small conductance calcium-dependent potassium currents (SK). TRN-restricted deletion of Ptchd1 leads to attention deficits and hyperactivity, both of which are rescued by pharmacological augmentation of SK channel activity. Global Ptchd1 deletion recapitulates learning impairment, hyper-aggression, and motor defects, all of which are insensitive to SK pharmacological targeting and not found in the TRN-restricted deletion mouse. This study maps clinically relevant behavioural phenotypes onto TRN dysfunction in a human disease model, while also identifying molecular and circuit targets for intervention. PMID:27007844

  16. Thalamic ventrobasal stimulation for pain relief: probable mechanisms, pathways and neurotransmitters

    Directory of Open Access Journals (Sweden)

    Osvaldo Vilela Filho

    1994-12-01

    Full Text Available Thalamic ventrobasal (VB stimulation, first performed by Mazars, in 1961, is a valuable means for treating central and deafferentation pain. The way it acts to achieve pain relief, however, is still a matter of controversy. In this paper, the author examines previously proposed hypotheses and suggests that VB stimulation induces pain relief by activation of a multisynaptyic inhibitory pathway to the medial thalamus, in which the dopaminergic nigrostriatal system exerts an important role and by modulation of abnormal activity in VB itself. The multisynaptic pathway involved, as well as the neurotransmitters, are suggested: VB stimulation excites somatosensory cortex through the glutaminergic thalamocortical pathway, which in turn, sends excitatory glutaminergic axons to the motor cortex. The sensorymotor cortex originates the excitatory glutaminergic corticostriatal pathway to the anterior putamen. The anterior putamen sends excitatory peptidergic (substance P pathways to the globus pallidus interims (striatopallidal pathway and to the substantia nigra reticulata (striatonigral pathway. The globus pallidus interims inhibits the medial thalamus through the pallidothalamic GABAergic pathway. The substantia nigra reticulata sends inhibitory GABAergic projections to the medial thalamus (nigrothalamic pathway and excites the substantia nigra compacta. The substantia nigra compacta projects excitatory dopaminergic axons to the striatal neurons (nigrostriatal pathway with output to the globus pallidus internus and substantia nigra reticulata and so on. Data to support this hypothesis are provided by an extensive review of the literature.

  17. Ophthalmoplegic migraine with reversible thalamic ischemia by Tc-99m ethylcysteinate dimer brain SPECT

    International Nuclear Information System (INIS)

    Two patients presented with ophthalmoplegic migraine (OM) underwent EEG, Brain-MRI, cerebral angiography, and Tc-99m ECD SPECT during an attack. Follow-up SPECT was performed after neurologic symptoms resolved. In both cases, SPECT during an attack of ophthalmoplegia and headache demonstrated a significantly decreased regional cerebral blood flow in the thalamus to the side of ophthalmoplegia, which was normalized on the follow-up SPECT during a symptom free recovery phase (Lesion to Non-lesion thalamic ratio=1.19 to 0.96 and 1.16 to 0.98, respectively). The other roentgenographic and laboratory findings were normal. These findings are suggestive the ischemia in the perforators of PCA results in third nerve palsy because the portion of oculomotor nerve behind the cavernous sinus derives its blood supply from small perforating branches of the basilar and PCA. Matched ictal hypoperfusion of the thalamus to the site of ophthalmoplegic migraine is suggestive of the ischemic neuropathy as an etiology of OM

  18. Simple cortical and thalamic neuron models for digital arithmetic circuit implementation

    Directory of Open Access Journals (Sweden)

    Takuya eNanami

    2016-05-01

    Full Text Available Trade-off between reproducibility of neuronal activities and computational efficiency is one ofcrucial subjects in computational neuroscience and neuromorphic engineering. A wide variety ofneuronal models have been studied from different viewpoints. The digital spiking silicon neuron(DSSN model is a qualitative model that focuses on efficient implementation by digital arithmeticcircuits. We expanded the DSSN model and found appropriate parameter sets with which itreproduces the dynamical behaviors of the ionic-conductance models of four classes of corticaland thalamic neurons. We first developed a 4-variable model by reducing the number of variablesin the ionic-conductance models and elucidated its mathematical structures using bifurcationanalysis. Then, expanded DSSN models were constructed that reproduce these mathematicalstructures and capture the characteristic behavior of each neuron class. We confirmed thatstatistics of the neuronal spike sequences are similar in the DSSN and the ionic-conductancemodels. Computational cost of the DSSN model is larger than that of the recent sophisticatedIntegrate-and-Fire-based models, but smaller than the ionic-conductance models. This modelis intended to provide another meeting point for above trade-off that satisfies the demand forlarge-scale neuronal network simulation with closer-to-biology models.

  19. Imaging dopamine transmission in schizophrenia

    Energy Technology Data Exchange (ETDEWEB)

    Laruelle, M. [New York, Columbia Univ. College of Physicians and Surgeons, NY (United States). New York State Psychiatric Insitute. Brain Imaging Division

    1998-09-01

    Over the last ten years, several positron emission tomography (PET) and single photon computerized tomography (SPECT) studies of the dopamine (DA) system in patients with schizophrenia were performed to test the hypothesis that DA hyperactivity is associated with this illness. In this paper are reviewed the results of fifteen brain imaging studies comparing indices of DA function in drug naive or drug free patients with schizophrenia and healthy controls: thirteen studies included measurements of Da D{sub 2} receptor density, two studies compared amphetamine-induced DA release, and two studies measured DOPA decarboxylase activity, an enzyme involved in DA synthesis. It was conducted a meta-analysis of the studies measuring D{sub 2} receptor density parameters, under the assumption that all tracers labeled the same population of D{sub 2} receptors. This analysis revealed that, compared to healthy controls, patients with schizophrenia present a significant but mild elevation of D{sub 2} receptor density parameters and a significant larger variability of these indices. It was found no statistical evidence that studies performed with radiolabeled butyrophenones detected a larger increase in D{sub 2} receptor density parameters than studies performed with other radioligands, such as benzamides. Studies of presynaptic activity revealed an increase in DA transmission response to amphetamine challenge, and an increase in DOPA decarboxylase activity. Together, these data are compatible with both pre- and post-synaptic alterations of DA transmission in schizophrenia. Future studies should aim at a better characterization of these alterations, and at defining their role in the pathophysiology of the illness.

  20. Excitatory neuromodulator reduces dopamine release, enhancing prolactin secretion

    OpenAIRE

    van den Pol, Anthony N.

    2010-01-01

    Hypothalamic dopamine neurons inhibit pituitary prolactin secretion. In this issue, Lyons et al provide evidence for a novel model, whereby the excitatory neuropeptide TRH depolarizes gap junction-coupled dopamine neurons, leading to a shift in the population pattern of action potentials from phasic burst firing to regular tonic firing, hypothetically reducing dopamine release while increasing total spike number.

  1. Progressive supranuclear palsy dopamine D2 receptor tomoscintigraphy to detect L-dopamine efficiency

    International Nuclear Information System (INIS)

    Progressive supranuclear palsy (PSP) may sometimes be misdiagnosed as Parkinson's disease in its early stages, hence an early positive diagnosis of PSP based on dopamine D2 receptor density could be extremely valuable. In the present case report, the absence of dopamine D2 receptors was clearly demonstrated in the striatum using 123I-iodobenzamide (IBZM) tomoscintigraphy. This illustrates the potential use of IBZM tomoscintigraphy to identify Parkinson-like's disease presenting with decreased dopamine D2 receptor density; and hence to predict L-Dopa effectiveness. Further studies are needed to evaluate the value of IBZM tomoscintigraphy in the different Parkinson's like diseases. (authors). 11 refs., 2 figs

  2. Improvements relating to glove boxes

    International Nuclear Information System (INIS)

    It is stated that radiation problems with glove boxes can only be partly overcome by adding shielding to their working faces, since about 25% of the working face may be taken up with glove ports at which the only shielding provided is that of the glove. A glove port cover is here described, mountable above the port, comprising a number of flaps of lead-loaded flexible material. The flaps can be pushed aside by hand to permit access to a glove fixed in the port, but overlap to close off the port when the hand is withdrawn. The lead loaded flexible material preferably has a natural or synthetic rubber base. Constructional details are given. Only the flaps need to be lead-loaded, and to facilitate manufacture and handling the surfaces of the cover are preferably lead-free. Three flaps can suffice, but five or six are preferred. For mounting purposes a cover may have beading at its periphery for clamped location in a groove round the glove port. (U.K.)

  3. NOVEL FLUORESCENT PROBES FOR THE DOPAMINE TRANSPORTER

    DEFF Research Database (Denmark)

    Cha, J; Vægter, Christian Bjerggaard; Adkins, Erica;

    To enable visualization of the dopamine transporter (DAT) through fluorescence technologies we have synthesized a novel series of fluorescently tagged analogs of cocaine. Previous structure-activity relationship (SAR) studies have demonstrated that the dopamine transporter (DAT) can tolerate...... untransfected control cells. The possibility of using these ligands for direct labeling of the DAT in living cells represents a new and important approach for understanding cellular targeting and trafficking of the DAT. Moreover, these fluorescent ligands might also provide the molecular tools for the...

  4. Dopamine transporter imaging in neurodegenerative disorders

    International Nuclear Information System (INIS)

    The dopamine transporter (DAT) is responsible for the re-uptake of dopamine from the synaptic cleft and is located on dopaminergic nerve terminals only. DAT single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging, therefore, offer the unique opportunity to study via striatal uptake the integrity of presynaptic dopaminergic nerve terminals in vivo. In recent years SPECT and PET using specific ligands binding to DAT have evolved as an useful tool for diagnosing and monitoring progression of neurodegenerative disorders affecting dopaminergic systems. This article briefly reviews the literature dealing with DTA SPECT and PET imaging in Parkinsonism and other neurodegenerative disorders

  5. Cellular regulation of the dopamine transporter

    DEFF Research Database (Denmark)

    Eriksen, Jacob

    2010-01-01

    The dopamine transporter (DAT) mediates reuptake of dopamine from the synaptic cleft and is a target for widely abused psychostimulants such as cocaine and amphetamine. Nonetheless, little is known about the cellular distribution and trafficking of natively expressed DAT. DAT and its trafficking...... single-membrane spanning protein Tac, thereby creating an extracellular antibody epitope. Upon expression in HEK293 cells this TacDAT fusion protein displayed functional properties similar to the wild type transporter. In an ELISA based internalization assay, TacDAT intracellular accumulation was...

  6. Contribution of vesicular and cytosolic dopamine to the increased striatal dopamine efflux elicited by intrastriatal injection of dexamphetamine.

    NARCIS (Netherlands)

    Watanabe, S.; Aono, Y.; Fusa, K.; Takada, K.; Saigusa, T.; Koshikawa, N.; Cools, A.R.

    2005-01-01

    Systemic administration of high doses of dexamphetamine induces a dopamine efflux that has its intracellular origin in both the vesicular, reserpine-sensitive dopamine pool and the cytosolic, alpha-methyl-para-tyrosine-sensitive, newly synthesized dopamine pool. It remains unknown whether locally ad

  7. Fluctuation of the dopamine uptake inhibition potency of cocaine, but not amphetamine, at mammalian cells expressing the dopamine transporter

    OpenAIRE

    Ukairo, Okechukwu T.; Ramanujapuram, Suneetha; Surratt, Christopher K.

    2006-01-01

    Cocaine, amphetamines and other psychostimulants inhibit synaptic dopamine uptake by interfering with dopamine transporter (DAT) function. The resultant potentiation of dopaminergic neurotransmission is associated with psychostimulant addiction. Fluctuations in dopamine uptake inhibition potency (DUIP) were observed for classical DAT blockers including cocaine, mazindol, methylphenidate (Ritalin™) and benztropine in CHO cells expressing wildtype DAT; cocaine potency also decreased in DAT-expr...

  8. Characterization of high affinity dopamine uptake into the dopamine neurons of the hypothalamus

    International Nuclear Information System (INIS)

    In this study the authors have examined the uptake of tritiated dopamine into the nerve terminals of hypothalamic DA neurons, which were isolated pharmacologically from NE neurons using desmethylimipramine (DMI), an inhibitor of catecholamine uptake into NE neurons. (Auth.)

  9. Dopamine induces neutrophil apoptosis through a dopamine D-1 receptor-independent mechanism.

    LENUS (Irish Health Repository)

    Sookhai, S

    2012-02-03

    BACKGROUND: For the normal resolution of an acute inflammatory response, neutrophil (PMN) apoptosis is essential to maintain immune homeostasis and to limit inappropriate host tissue damage. A delay in PMN apoptosis has been implicated in the pathogenesis of the systemic inflammatory response syndrome (SIRS). Dopamine, a biogenic amine with known cardiovascular and neurotransmitter properties, is used in patients with SIRS to maintain hemodynamic stability. We sought to determine whether dopamine may also have immunoregulatory properties capable of influencing PMN apoptosis, function, and activation state in patients with SIRS. METHODS: PMNs were isolated from healthy volunteers and patients with SIRS and treated with varying doses of dopamine and a dopamine D-1 receptor agonist, fenoldopam. PMN apoptosis was assessed every 6 hours with use of propidium iodide DNA staining and PMN function was assessed with use of respiratory burst activity, phagocytosis ability, and CD11a, CD11b, and CD18 receptor expression as functional markers. RESULTS: There was a significant delay in PMN apotosis in patients with SIRS compared with controls. Treatment of isolated PMNs from both healthy controls and patients with SIRS with 10 and 100 mumol\\/L dopamine induced apoptosis. PMN ingestive and cytocidal capacity were both decreased in patients with SIRS compared with controls. Treatment with dopamine significantly increased phagocytic function. Fenoldopam did not induce PMN apoptosis. CONCLUSION: Our data demonstrate for the first time that dopamine induces PMN apoptosis and modulates PMN function both in healthy controls and in patients with SIRS. These results indicate that dopamine may be beneficial during SIRS through a nonhemodynamic PMN-dependent proapoptotic mechanism.

  10. The binding sites for benztropines and dopamine in the dopamine transporter overlap

    DEFF Research Database (Denmark)

    Jensen, Heidi Bisgaard; Larsen, M Andreas B; Mazier, Sonia;

    2011-01-01

    Analogs of benztropines (BZTs) are potent inhibitors of the dopamine transporter (DAT) but are less effective than cocaine as behavioral stimulants. As a result, there have been efforts to evaluate these compounds as leads for potential medication for cocaine addiction. Here we use computational...... with a larger decrease in the affinity for BZT than for JHW007. Summarized, our data suggest that BZTs display a classical competitive binding mode with binding sites overlapping those of cocaine and dopamine....

  11. Packing a cake into a box

    KAUST Repository

    Skopenkov, Mikhail

    2011-05-01

    Given a triangular cake and a box in the shape of its mirror image, how can the cake be cut into a minimal number of pieces so that it can be put into the box? The cake has icing, so we are not allowed to put it into the box upside down. V. G. Boltyansky asked this question in 1977 and showed that three pieces always suffice. In this paper we provide examples of cakes that cannot be cut into two pieces to be put into the box. This shows that three is the answer to Boltyansky\\'s question. We also give examples of cakes which can be cut into two pieces. © THE MATHEMATICAL ASSOCIATION OF AMERICA.

  12. Spacer for supporting fuel element boxes

    International Nuclear Information System (INIS)

    A spacer plate unit arranged externally on each side and at a predetermined level of a polygonal fuel element box for mutually supporting, with respect to one another, a plurality of the fuel element boxes forming a fuel element bundle, is formed of a first and a second spacer plate part each having the same length and the same width and being constituted of unlike first and second materials, respectively. The first and second spacer plate parts of the several spacer plate units situated at the predetermined level are arranged in an alternating continuous series when viewed in the peripheral direction of the fuel element box, so that any two spacer plate units belonging to face-to-face oriented sides of two adjoining fuel element boxes in the fuel element bundle define interfaces of unlike materials

  13. Mystery Boxes, X Rays, and Radiology.

    Science.gov (United States)

    Thomson, Norman

    2000-01-01

    Indicates the difficulties of teaching concepts beyond light and color and creating memorable learning experiences. Recommends sequential activities using the mystery box approach to explain how scientists and doctors use photon applications. (YDS)

  14. Packing a cake into a box

    CERN Document Server

    Skopenkov, Mikhail

    2010-01-01

    Given a cake in form of a triangle and a box that fits the mirror image of the cake, how to cut the cake into a minimal number of pieces so that it can be put into the box? The cake has an icing, so that we are not allowed to put it into the box upside down. V.G. Boltyansky asked this question in 1977 and showed that three pieces always suffice. In this paper we provide examples of cakes that cannot be cut into two pieces to put into the box. This shows that three is the answer to V.G. Boltyansky's question. Also we give examples of cakes which can be cut into two pieces.

  15. The role of dopamine in a model of trigeminovascular nociception.

    Science.gov (United States)

    Akerman, S; Goadsby, P J

    2005-07-01

    Migraine is a common, disabling problem with three phases: premonitory, main headache attack, and postdrome. The headache phase is thought to involve activation of trigeminal neurons, whereas the premonitory and postdrome phases may involve dopaminergic mechanisms. In animal studies, dopamine has been found to cause vasodilation of cranial arteries at very low doses. Using intravital microscopy, we examined the effect of dopamine receptor agonists on dural blood vessel caliber and the effect of dopamine and specific dopamine receptor antagonists on trigeminovascular neurogenic dural vasodilation. Dopamine hydrochloride caused a significant vasoconstriction (P blood pressure (P dopamine receptor antagonists. The D1 receptor agonist caused a vasoconstriction (P blood pressure increase (P dopamine receptor antagonists were able to attenuate neurogenic dural vasodilation. Dopamine hydrochloride infusion (P dopamine agonist infusion. This response may be due to the vasoconstrictor effects of the alpha2-adrenoceptor and an action at the D1 receptor. In the intravital model of trigeminal activation, it seems that dopamine receptors do not play a major role and may not present an acute treatment option. Our data do not exclude a role for dopamine receptor modulators in short- or long-term prevention. PMID:15778266

  16. Antagonism of presynaptic dopamine receptors by phenothiazine drug metabolites

    International Nuclear Information System (INIS)

    Electrically evoked release of dopamine from the caudate nucleus is reduced by the dopamine receptor agonists, apomorphine and bromocriptine, and facilitated by neuroleptic drugs, which act as dopamine autoreceptor antagonists. The potencies of chlorpromazine, fluphenazine, levomepromazine and their hydroxy-metabolites in modulating electrically evoked release of dopamine were examined by superfusion of rabbit caudate nucleus slices pre-incubated with 3H-dopamine. O-Desmethyl levomepromazine, 3-hydroxy- and 7-hydroxy metabolites of chlorpromazine and levomepromazine facilitated electrically evoked release of 3H-dopamine, having potencies similar to that of the parent compounds. 7-Hydroxy fluphenazine was less active than fluphenazine in this system. These results indicate that phenolic metabolites of chlorpromazine and levomepromazine, but not of fluphenazine, may contribute to effects of the drugs mediated by presynaptic dopamine receptors

  17. Regulation of c-fos expression by the dopamine D1–D2 receptor heteromer

    Science.gov (United States)

    Perreault, Melissa L.; Shen, Maurice Y.F.; George, Susan R.

    2015-01-01

    The dopamine D1 and D2 receptors form the D1–D2 receptor heteromer in a subset of neurons and couple to the Gq protein to regulated intracellular calcium signaling. In the present study the effect of D1–D2 heteromer activation and disruption on neuronal activation in rat brain was mapped. This was accomplished using the dopamine agonist SKF 83959 to activate the D1–D2 heteromer in combination with a TAT-D1 disrupting peptide we developed, and which has been shown to disrupt the D1/D2 receptor interaction and antagonize D1–D2 heteromer-induced cell signaling and behaviour. Acute SKF 83959 administration to rats induced significant c-fos expression in nucleus accumbens that was significantly inhibited by TAT-D1 pretreatment. No effects of SKF 83959 were seen in caudate putamen. D1–D2 heteromer disruption by TAT-D1 did not have any effects in any striatal subregions, but induced significant c-fos immunoreactivity in a number of cortical regions including the orbitofrontal cortex, prelimbic and infralimbic cortices and the piriform cortex. The induction of c-fos by TAT-D1 was also evident in the anterior olfactory nucleus, as well as the lateral habenula and thalamic nuclei. These findings show for the first time that the D1–D2 heteromer can differentially regulate c-fos expression in a region-dependent manner either through its activation or through tonic inhibition of neuronal activity. PMID:25446350

  18. Prenatal L-DOPA exposure produces lasting changes in brain dopamine content, cocaine-induced dopamine release and cocaine conditioned place preference

    OpenAIRE

    Ren, Jia-Qian; Jiang, Yan; WANG, Zhihui; McCarthy, Deirdre; Rajadhyaksha, Anjali M.; Tropea, Thomas F.; Kosofsky, Barry E.; Bhide, Pradeep G.

    2010-01-01

    Dopamine, its receptors and transporter are present in the brain beginning from early in the embryonic period. Dopamine receptor activation can influence developmental events including neurogenesis, neuronal migration and differentiation raising the possibility that dopamine imbalance in the fetal brain can alter development of the brain and behavior. We examined whether elevated dopamine levels during gestation can produce persisting changes in brain dopamine content and dopamine-mediated be...

  19. Increased expression of the dopamine transporter leads to loss of dopamine neurons, oxidative stress and L-DOPA reversible motor deficits

    OpenAIRE

    Masoud, ST; Vecchio, LM; Bergeron, Y; Hossain, MM; Nguyen, LT; Bermejo, MK; Kile, B; Sotnikova, TD; Siesser, WB; Gainetdinov, Rr; Wightman, RM; Caron, MG; Richardson, JR; Miller, GW; Ramsey, AJ

    2014-01-01

    The dopamine transporter is a key protein responsible for regulating dopamine homeostasis. Its function is to transport dopamine from the extracellular space into the presynaptic neuron. Studies have suggested that accumulation of dopamine in the cytosol can trigger oxidative stress and neurotoxicity. Previously, ectopic expression of the dopamine transporter was shown to cause damage in non-dopaminergic neurons due to their inability to handle cytosolic dopamine. However, it is unknown wheth...

  20. Imaging extrastriatal dopamine D(2) receptor occupancy by endogenous dopamine in healthy humans.

    Science.gov (United States)

    Fujita, M; Verhoeff, N P; Varrone, A; Zoghbi, S S; Baldwin, R M; Jatlow, P A; Anderson, G M; Seibyl, J P; Innis, R B

    2000-01-10

    The effect of endogenous dopamine on in vivo measurement of dopamine D(2) receptors in extrastriatal regions (thalamus and temporal cortex) was evaluated with single photon emission computed tomography and the high affinity ligand [123I]epidepride by comparing the binding potential before and after acute dopamine depletion. Dopamine depletion was achieved by per-oral administration of 5.5 g/70 kg body weight alpha-methyl-para-tyrosine given in 37 h. The alpha-methyl-para-tyrosine treatment increased the binding potential significantly in the temporal cortex (13+/-15%, P=0.036) but not in the thalamus (2+/-9%). The increase of the binding potential in the temporal cortex correlated strongly with the increase of dysphoric mood evaluated by the Positive and Negative Symptom Scale (PANSS) (rho=0.88, P=0.004). These results imply that [123I]epidepride, coupled with acute dopamine depletion might provide estimates of synaptic dopamine concentration. PMID:10650158

  1. Decommissioning a tritium glove-box facility

    Energy Technology Data Exchange (ETDEWEB)

    Folkers, C.L.; Homann, S.G.; Nicolosi, A.S.; Hanel, S.L.; King, W.C.

    1979-08-08

    A large glove-box facility for handling reactive metal tritides was decommissioned. Major sections of the glove box were decontaminated and disassembled for reuse at another tritium facility. To achieve the desired results, decontamnation required repeated washing, first with organic liquids, then with water and detergents. Worker protection was provided by simple ventilation combined with careful monitoring of the work areas and employees. Several innovative techniques are described.

  2. Decommissioning a tritium glove-box facility

    International Nuclear Information System (INIS)

    A large glove-box facility for handling reactive metal tritides was decommissioned. Major sections of the glove box were decontaminated and disassembled for reuse at another tritium facility. To achieve the desired results, decontamnation required repeated washing, first with organic liquids, then with water and detergents. Worker protection was provided by simple ventilation combined with careful monitoring of the work areas and employees. Several innovative techniques are described

  3. SET Backaction on the Single Electron Box

    OpenAIRE

    Turek, B. A.; Lehnert, K. W.; Clerk, A.; Gunnarsson, D.; Bladh, K.; Delsing, P.; Schoelkopf, R. J.

    2005-01-01

    We report an experimental observation of the backaction of a Single Electron Transistor (SET) measuring the Coulomb staircase of a single electron box. As current flows through the SET, the charge state of the SET island fluctuates. These fluctuations capacitively couple to the box and cause changes in the position, width, and asymmetry of the Coulomb staircase. A sequential tunnelling model accurately recreates these effects, confirming this mechanism of the backaction of an SET. This is a f...

  4. Random Young diagrams in a Rectangular Box

    DEFF Research Database (Denmark)

    Beltoft, Dan; Boutillier, Cédric; Enriquez, Nathanaël

    We exhibit the limit shape of random Young diagrams having a distribution proportional to the exponential of their area, and confined in a rectangular box. The Ornstein-Uhlenbeck bridge arises from the fluctuations around the limit shape.......We exhibit the limit shape of random Young diagrams having a distribution proportional to the exponential of their area, and confined in a rectangular box. The Ornstein-Uhlenbeck bridge arises from the fluctuations around the limit shape....

  5. Oscillating from Neurosecretion to Multitasking Dopamine Neurons

    Directory of Open Access Journals (Sweden)

    David R. Grattan

    2016-04-01

    Full Text Available In this issue of Cell Reports, Stagkourakis et al. (2016 report that oscillating hypothalamic TIDA neurons, previously thought to be simple neurosecretory neurons controlling pituitary prolactin secretion, control dopamine output via autoregulatory mechanisms and thus could potentially regulate other physiologically important hypothalamic neuronal circuits.

  6. Oscillating from Neurosecretion to Multitasking Dopamine Neurons.

    Science.gov (United States)

    Grattan, David R; Akopian, Armen N

    2016-04-26

    In this issue of Cell Reports, Stagkourakis et al. (2016) report that oscillating hypothalamic TIDA neurons, previously thought to be simple neurosecretory neurons controlling pituitary prolactin secretion, control dopamine output via autoregulatory mechanisms and thus could potentially regulate other physiologically important hypothalamic neuronal circuits. PMID:27119847

  7. Oscillating from Neurosecretion to Multitasking Dopamine Neurons

    Science.gov (United States)

    Grattan, David R.; Akopian, Armen N.

    2016-01-01

    In this issue of Cell Reports, Stagkourakis et al. (2016) report that oscillating hypothalamic TIDA neurons, previously thought to be simple neurosecretory neurons controlling pituitary prolactin secretion, control dopamine output via autoregulatory mechanisms and thus could potentially regulate other physiologically important hypothalamic neuronal circuits. PMID:27119847

  8. Nerve cell loss in the thalamic centromedian-parafascicular complex in patients with Huntington's disease.

    Science.gov (United States)

    Heinsen, H; Rüb, U; Gangnus, D; Jungkunz, G; Bauer, M; Ulmar, G; Bethke, B; Schüler, M; Böcker, F; Eisenmenger, W; Götz, M; Strik, M

    1996-01-01

    The centromedian-parafascicular complex represents a nodal point in the neuronal loop comprising striatum--globulus pallidus--thalamus--striatum. Striatal neurone degeneration is a hallmark in Huntington's disease and we were interested in estimating total neurone and glial number in this thalamic nuclear complex. Serial 500-microns-thick gallocyanin-stained frontal sections of the left hemisphere from six cases of Huntington's disease patients (three females, three males) and six age- and sex-matched controls were investigated applying Cavalieri's principle and the optical disector. Mean neurone number in the controls was 646,952 +/- 129,668 cells versus 291,763 +/- 60,122 in Huntington's disease patients (Mann-Whitney U-test, P < 0.001). Total glial cell number (astrocytes, oligodendrocytes, microglia, and unclassifiable glial profiles) was higher in controls with 9,544,191 +/- 3,028,944 versus 6,961,989 +/- 2,241,543 in Huntington's disease patients (Mann-Whitney U-test, P < 0.021). Considerable increase of fibrous astroglia within the centromedian-parafascicular complex could be observed after Gallyas' impregnation. Most probably this cell type enhanced the numerical ratio between glial number and neurone number (glial index: Huntington's disease patients = 24.4 +/- 8.1; controls = 15.0 +/- 5.2; Mann-Whitney U-test, P < 0.013). The neurone number in the centromedian-parafascicular complex correlated negatively, although statistically not significantly, with the striatal neurone number. This lack of correlation between an 80% neuronal loss in the striatum and a 55% neurone loss in the centromedian-parafascicular complex points to viable neuronal circuits connecting the centromedian-parafascicular complex with cortical and subcortical regions that are less affected in Huntington's disease. PMID:8787149

  9. Thalamic mediodorsal nucleus and its participation in spatial working memory processes: comparison with the prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Shintaro Funahashi

    2013-07-01

    Full Text Available Working memory is a dynamic neural system that includes processes for temporarily maintaining and processing information. Working memory plays a significant role in a variety of cognitive functions, such as thinking, reasoning, decision-making, and language comprehension. Although the prefrontal cortex (PFC is known to play an important role in working memory, several lines of evidence indicate that the thalamic mediodorsal nucleus (MD also participates in this process. While monkeys perform spatial working memory tasks, MD neurons exhibit directionally selective delay-period activity, which is considered to be a neural correlate for the temporary maintenance of information in PFC neurons. Studies have also shown that, while most MD neurons maintain prospective motor information, some maintain retrospective sensory information. Thus, the MD plays a greater role in prospective motor aspects of working memory processes than the PFC, which participates more in retrospective aspects. For the performance of spatial working memory tasks, the information provided by a sensory cue needs to be transformed into motor information to give an appropriate response. A population vector analysis using neural activities revealed that, although the transformation of sensory-to-motor information occurred during the delay period in both the PFC and the MD, PFC activities maintained sensory information until the late phase of the delay period, while MD activities initially represented sensory information but then started to represent motor information in the earlier phase of the delay period. These results indicate that long-range neural interactions supported by reciprocal connections between the MD and the PFC could play an important role in the transformation of maintained information in working memory processes.

  10. Early postnatal switch in GABAA receptor α-subunits in the reticular thalamic nucleus.

    Science.gov (United States)

    Pangratz-Fuehrer, Susanne; Sieghart, Werner; Rudolph, Uwe; Parada, Isabel; Huguenard, John R

    2016-03-01

    The GABAergic neurons of the thalamic reticular nucleus (nRt) provide the primary source of inhibition within the thalamus. Using physiology, pharmacology, and immunohistochemistry in mice, we characterized postsynaptic developmental changes in these inhibitory projection neurons. First, at postnatal days 3-5 (P3-5), inhibitory postsynaptic currents (IPSCs) decayed very slowly, followed by a biphasic developmental progression, becoming faster at P6-8 and then slower again at P9-11 before stabilizing in a mature form around P12. Second, the pharmacological profile of GABA(A) receptor (GABA(A)R)-mediated IPSCs differed between neonatal and mature nRt neurons, and this was accompanied by reciprocal changes in α3 (late) and α5 (early) subunit expression in nRt. Zolpidem, selective for α1- and α3-containing GABA(A)Rs, augmented only mature IPSCs, whereas clonazepam enhanced IPSCs at all stages. This effect was blocked by the α5-specific inverse agonist L-655,708, but only in immature neurons. In α3(H126R) mice, in which α3-subunits were mutated to become benzodiazepine insensitive, IPSCs were enhanced compared with those in wild-type animals in early development. Third, tonic GABA(A)R activation in nRt is age dependent and more prominent in immature neurons, which correlates with early expression of α5-containing GABA(A)Rs. Thus neonatal nRt neurons show relatively high expression of α5-subunits, which contributes to both slow synaptic and tonic extrasynaptic inhibition. The postnatal switch in GABA(A)R subunits from α5 to α3 could facilitate spontaneous network activity in nRt that occurs at this developmental time point and which is proposed to play a role in early circuit development. PMID:26631150

  11. Functional interactions between dentate gyrus, striatum and anterior thalamic nuclei on spatial memory retrieval.

    Science.gov (United States)

    Méndez-Couz, M; Conejo, N M; González-Pardo, H; Arias, J L

    2015-04-24

    The standard model of memory system consolidation supports the temporal reorganization of brain circuits underlying long-term memory storage, including interactions between the dorsal hippocampus and extra-hippocampal structures. In addition, several brain regions have been suggested to be involved in the retrieval of spatial memory. In particular, several authors reported a possible role of the ventral portion of the hippocampus together with the thalamus or the striatum in the persistence of this type of memory. Accordingly, the present study aimed to evaluate the contribution of different cortical and subcortical brain regions, and neural networks involved in spatial memory retrieval. For this purpose, we used cytochrome c oxidase quantitative histochemistry as a reliable method to measure brain oxidative metabolism. Animals were trained in a hidden platform task and tested for memory retention immediately after the last training session; one week after completing the task, they were also tested in a memory retrieval probe. Results showed that retrieval of the previously learned task was associated with increased levels of oxidative metabolism in the prefrontal cortex, the dorsal and ventral striatum, the anterodorsal thalamic nucleus and the dentate gyrus of the dorsal and ventral hippocampus. The analysis of functional interactions between brain regions suggest that the dorsal and ventral dentate gyrus could be involved in spatial memory retrieval. In addition, the results highlight the key role of the extended hippocampal system, thalamus and striatum in this process. Our study agrees with previous ones reporting interactions between the dorsal hippocampus and the prefrontal cortex during spatial memory retrieval. Furthermore, novel activation patterns of brain networks involving the aforementioned regions were found. These functional brain networks could underlie spatial memory retrieval evaluated in the Morris water maze task. PMID:25680583

  12. Thalamic Kv7 channels: pharmacological properties and activity control during noxious signal processing

    Science.gov (United States)

    Cerina, Manuela; Szkudlarek, Hanna J; Coulon, Philippe; Meuth, Patrick; Kanyshkova, Tatyana; Nguyen, Xuan Vinh; Göbel, Kerstin; Seidenbecher, Thomas; Meuth, Sven G; Pape, Hans-Christian; Budde, Thomas

    2015-01-01

    Background and Purpose The existence of functional Kv7 channels in thalamocortical (TC) relay neurons and the effects of the K+-current termed M-current (IM) on thalamic signal processing have long been debated. Immunocytochemical evidence suggests their presence in this brain region. Therefore, we aimed to verify their existence, pharmacological properties and function in regulating activity in neurons of the ventrobasal thalamus (VB). Experimental Approach Characterization of Kv7 channels was performed by combining in vitro, in vivo and in silico techniques with a pharmacological approach. Retigabine (30 μM) and XE991 (20 μM), a specific Kv7 channel enhancer and blocker, respectively, were applied in acute brain slices during electrophysiological recordings. The effects of intrathalamic injection of retigabine (3 mM, 300 nL) and/or XE991 (2 mM, 300 nL) were investigated in freely moving animals during hot-plate tests by recording behaviour and neuronal activity. Key Results Kv7.2 and Kv7.3 subunits were found to be abundantly expressed in TC neurons of mouse VB. A slow K+-current with properties of IM was activated by retigabine and inhibited by XE991. Kv7 channel activation evoked membrane hyperpolarization, a reduction in tonic action potential firing, and increased burst firing in vitro and in computational models. Single-unit recordings and pharmacological intervention demonstrated a specific burst-firing increase upon IM activation in vivo. A Kv7 channel-mediated increase in pain threshold was associated with fewer VB units responding to noxious stimuli, and increased burst firing in responsive neurons. Conclusions and Implications Kv7 channel enhancement alters somatosensory activity and may reflect an anti-nociceptive mechanism during acute pain processing. PMID:25684311

  13. Losing the struggle to stay awake: divergent thalamic and cortical activity during microsleeps.

    Science.gov (United States)

    Poudel, Govinda R; Innes, Carrie R H; Bones, Philip J; Watts, Richard; Jones, Richard D

    2014-01-01

    Maintaining alertness is critical for safe and successful performance of most human activities. Consequently, microsleeps during continuous visuomotor tasks, such as driving, can be very serious, not only disrupting performance but sometimes leading to injury or death due to accidents. We have investigated the neural activity underlying behavioral microsleeps--brief (0.5-15 s) episodes of complete failure to respond accompanied by slow eye-closures--and EEG theta activity during drowsiness in a continuous task. Twenty healthy normally-rested participants performed a 50-min continuous tracking task while fMRI, EEG, eye-video, and responses were simultaneously recorded. Visual rating of performance and eye-video revealed that 70% of the participants had frequent microsleeps. fMRI analysis revealed a transient decrease in thalamic, posterior cingulate, and occipital cortex activity and an increase in frontal, posterior parietal, and parahippocampal activity during microsleeps. The transient activity was modulated by the duration of the microsleep. In subjects with frequent microsleeps, power in the post-central EEG theta was positively correlated with the BOLD signal in the thalamus, basal forebrain, and visual, posterior parietal, and prefrontal cortices. These results provide evidence for distinct neural changes associated with microsleeps and with EEG theta activity during drowsiness in a continuous task. They also suggest that the occurrence of microsleeps during an active task is not a global deactivation process but involves localized activation of fronto-parietal cortex, which, despite a transient loss of arousal, may constitute a mechanism by which these regions try to restore responsiveness. PMID:23008180

  14. HYDROGEN AND VOC RETENTION IN WASTE BOXES

    Energy Technology Data Exchange (ETDEWEB)

    PACE ME; MARUSICH RM

    2008-11-21

    The Hanford Waste Management Project Master Documented Safety Analysis (MDSA) (HNF-14741, 2003) identifies derived safety controls to prevent or mitigate the risks of a single-container deflagration during operations requiring moving, venting or opening transuranic (TRU)-waste containers. The issue is whether these safety controls are necessary for operations involving TRU-waste boxes that are being retrieved from burial at the Hanford Site. This paper investigates the potential for a deflagration hazard within these boxes and whether safety controls identified for drum deflagration hazards should be applied to operations involving these boxes. The study evaluates the accumulation of hydrogen and VOCs within the waste box and the transport of these gases and vapors out of the waste box. To perform the analysis, there were numerous and major assumptions made regarding the generation rate and the transport pathway dimensions and their number. Since there is little actual data with regards to these assumptions, analyses of three potential configurations were performed to obtain some indication of the bounds of the issue (the concentration of hydrogen or flammable VOCs within a waste box). A brief description of each of the three cases along with the results of the analysis is summarized.

  15. Multiple Sclerosis: Changes in Thalamic Resting-State Functional Connectivity Induced by a Home-based Cognitive Rehabilitation Program.

    Science.gov (United States)

    De Giglio, Laura; Tona, Francesca; De Luca, Francesca; Petsas, Nikolaos; Prosperini, Luca; Bianchi, Valentina; Pozzilli, Carlo; Pantano, Patrizia

    2016-07-01

    Purpose To investigate thalamic connectivity changes after use of a video game-based cognitive rehabilitation program, as thalamic damage and alterations in thalamocortical functional connectivity (FC) are important factors in cognitive dysfunction in patients with multiple sclerosis (MS). Materials and Methods This prospective study was approved by the local ethical committee. Twenty-four patients with MS and cognitive impairment were randomly assigned to either an intervention or a wait-list group. Patients were evaluated with cognitive tests and 3-T resting-state functional magnetic resonance (MR) imaging at baseline and after an 8-week period. In addition, 11 healthy subjects underwent baseline resting-state functional MR imaging. Patients in the intervention group performed the video game-based cognitive rehabilitation program, while those in the wait-list group served as control subjects. Repeated measures analysis of variance was used to test efficacy of the intervention. The thalamic resting-state network was identified with a seed-based method; both first-level and high-level analyses were performed by using software tools. Results Patients showed lower baseline FC compared with healthy subjects. A significant improvement was seen in results of the Paced Auditory Serial Addition Test and the Stroop Test after 8 weeks of cognitive rehabilitation (F = 6.616, [P = .018] and F = 5.325 [P = .030], respectively). At follow-up, the intervention group had an increased FC in the cingulum, precuneus, and bilateral parietal cortex and a lower FC in the cerebellum and in left prefrontal cortex compared with the wait-list group (P game-based cognitive rehabilitation program. (©) RSNA, 2016. PMID:26953867

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

    Directory of Open Access Journals (Sweden)

    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

  17. Prognosis of thalamic hemorrhage with special reference to the level of consciousness and CT findings on admission

    International Nuclear Information System (INIS)

    The prognosis of thalamic hemorrhage was studied on the basis of neurological gradings on admission, mode of extension and hematoma size on brain CT. The subjects were 126 patients with thalamic hemorrhage who were admitted to Ashikaga Red Cross Hospital during the past ten years. Among the subjects, 120 patients (ages 64±10 yr; mean ±SD) were treated with conservative therapy, and 6 patients (ages 59±10 yr) with surgical therapy (ventricular drainage). Brain CT scans were done within 48 hours after onset in all patients. Neurological gradings, brain CT classification and prognosis were investigated according to the criteria of the Japanese Conference on Surgery for Cerebral Stroke. The results of conservative therapy were as follows: (1) In the grade I group on the neurological gradings, 29 of the 39 patients (74%) recovered to full work or an independent life, and none of them died. In the grade IV and V groups, mortality rate was 86%. (2) The prognosis was more unfavorable in type III than in types I and II on the CT classification. Twenty-six of the 36 patients (73%) with type I-a recovered to full work or an independent life. Twenty-five of the 34 patients (74%) with the type III-b died. (3) Only 4 of the 75 patients (5%) with less than 10 ml of hematoma volume died. In contrast, all 14 patients with more than 25 ml of hematoma volume died. (4) The mortality rate among patients with ventricular rupture (47%) was significantly higher than that among patients without ventricular rupture (2%) (p<0.001). (5) The mortality rate of patients with acute hydrocephalus (83%) was significantly higher than that of patients without acute hydrocephalus (20%) (p<0.001). From the above results, it is suggested that neurological grading, brain CT classification, hematoma volume, ventricular rupture and acute hydrocephalus are important prognostic factors for thalamic hemorrhage. (author)

  18. Analysis of correlation between white matter changes and functional responses in thalamic stroke: a DTI & EEG study.

    Science.gov (United States)

    Duru, Adil Deniz; Duru, Dilek Göksel; Yumerhodzha, Sami; Bebek, Nerses

    2016-06-01

    Diffusion tensor imaging (DTI) allows in vivo structural brain mapping and detection of microstructural disruption of white matter (WM). One of the commonly used parameters for grading the anisotropic diffusivity in WM is fractional anisotropy (FA). FA value helps to quantify the directionality of the local tract bundle. Therefore, FA images are being used in voxelwise statistical analyses (VSA). The present study used Tract-Based Spatial Statistics (TBSS) of FA images across subjects, and computes the mean skeleton map to detect voxelwise knowledge of the tracts yielding to groupwise comparison. The skeleton image illustrates WM structure and shows any changes caused by brain damage. The microstructure of WM in thalamic stroke is investigated, and the VSA results of healthy control and thalamic stroke patients are reported. It has been shown that several skeleton regions were affected subject to the presence of thalamic stroke (FWE, p power values and FA values of the skeleton was found to support the cortico-thalamocortical cycles for both subject groups. Further, the neurophysiological tests including Benton Face Recognition (BFR), Digit Span test (DST), Warrington Topographic Memory test (WTMT), California Verbal Learning test (CVLT) has been regressed with the FA skeleton maps for both subject groups. Our results corresponding to DST task were found to be similar with previously reported findings for working memory and episodic memory tasks. For the WTMT, FA values of the cingulum (right) that plays a role in memory process was found to be related with the behavioral responses. Splenium of corpus callosum was found to be correlated for both subject groups for the BFR. PMID:25957181

  19. Unilateral asterixis, thalamic astasia and vertical one and half syndrome in a unilateral posterior thalamo-subthalamic paramedian infarct: An interesting case report

    Directory of Open Access Journals (Sweden)

    Subasree Ramakrishnan

    2013-01-01

    Full Text Available A 42-year-old young lady presented with acute onset of dizziness, drooping of left eye with binocular diplopia and inability to walk unassisted. She had past history of uncontrolled diabetes mellitus and hypertension. On examination, she had left fascicular type of third nerve palsy, vertical one and half syndrome (VOHS, left internuclear ophthalmoplegia and skew deviation with ipsilesional hypertropia. She also had thalamic astasia and right unilateral asterixis. Her MRI revealed T2 and Flair hyper intense signal changes with restricted diffusion in the left thalamus, subthalamus and left midbrain. MR Angiography was normal. Thalamic-subthalamic paramedian territory infarct is relatively uncommon. It can present with oculomotor abnormalities including vertical one and half syndrome, skew deviation, thalamic astasia and asterixis. This case is reported for the rarity of the presenting clinical findings in unilateral thalamo-mesencephalic infarcts.

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

    OpenAIRE

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

    2013-01-01

    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...

  1. Tc-99m ECD brain SPECT in patients with traumatic brain injury: evaluating distribution of hypoperfusion and assessment of cognitive and behavioral impairment in relation to thalamic hypoperfusion

    International Nuclear Information System (INIS)

    We evaluated the distribution of hypoperfusion in patients with traumatic brain injury (TBI) and the relationship of thalamic hypoperfusion to severity of cognitive and behavioral sequelae. Tc-99m ECD SPECT and MRI were performed in 103 patients (M/F=81/22, mean age 34.7± 15.4 yrs) from 0.5 to 55 months (mean 10.3 months) after TBI. The patients were divided into three groups showing no abnormalities (G1), focal (G2) and diffuse injury (G3) on MRI. Psychometric tests assessed 11 cognitive or behavioral items. In all patients, we evaluated the distribution of hypoperfused areas in SPECT, and in 57/103 patients, neuropsychological (NP) abnormalities in patients with thalamic hypoperfusion were compared with those of patients without thalamic hypoperfusion. The perfusion dificits were most frequently located in the frontal lobe (G1, 42.3%: G2 34.5%: G3 33.3%), temporal lobe (24∼26%) thalami (21∼22.4%), parietal and occipital lobe (≤10%). Numbers of NP abnormalities in the cases of cortical hypoperfusion with or without concomitant thalamic hypoperfusion were following: the former 4.7±1.5 and the latter 3.2±1.4 in G1, 5.0±1.1 and 4.8±1.2 in G2, 6.8±1.8 and 6.3±1.1 in G3, respectively. This difference according to thalamic hypoperfusion was significant in G1 (p=0.002), but was not significant in G2 or G3. SPECT in patients with TBI had demonstrated hypoperfusion mostly involving the frontal, temporal and thalami. In normal group on MRI, frontal hypoperfusion was more prominent than that of any other group, Furthermore in this group, SPECT could predict severity of NP outcome by concomitant thalamic hypoperfusion with cerebral cortical abnormalities

  2. 49 CFR 178.517 - Standards for plastic boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for plastic boxes. 178.517 Section 178... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.517 Standards for plastic boxes. (a) The following are identification codes for plastic boxes: (1) 4H1 for an expanded plastic box; and (2) 4H2 for...

  3. 49 CFR 230.101 - Steam locomotive driving journal boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive driving journal boxes. 230.101... Locomotives and Tenders Running Gear § 230.101 Steam locomotive driving journal boxes. (a) Driving journal boxes. Driving journal boxes shall be maintained in a safe and suitable condition for service. Not...

  4. Effect of an odor eliminator on feline litter box behavior.

    Science.gov (United States)

    Cottam, Nicole; Dodman, Nicholas H

    2007-02-01

    Decreasing litter box odor may be an important treatment component in addressing feline inappropriate elimination. A three-phase study was conducted to determine if the use of Zero Odor litter box spray increases the preference of litter boxes to cats, presumably by its odor-eliminating quality. In the first phase, cats were given a litter box preference test between a litter box sprayed with Zero Odor and one without. In the second phase, the number of occurrences of behaviors indicative of a cat's dissatisfaction with the litter box (scratching at the sides of the box, floor or wall, hesitating when entering the litter box, balancing on the side of the box and eliminating outside of the litter box) was compared before and after the use of Zero Odor. Last, the frequency of eliminations that occurred outside the litter box was measured during a baseline phase and a test phase, in which Zero Odor was sprayed into all litter boxes in the home. Significantly fewer behaviors associated with feline litter box dissatisfaction and fewer undesirable eliminations were observed in phases 2 and 3, respectively. These findings suggest that use of Zero Odor litter box spray appears to decrease litter box odor and increases the attractiveness of litter box to cats. PMID:17049291

  5. 49 CFR 178.514 - Standards for plywood boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for plywood boxes. 178.514 Section 178... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.514 Standards for plywood boxes. (a) The identification code for a plywood box is 4D. (b) Construction requirements for plywood boxes are as follows:...

  6. Sensitivity of binding of high-affinity dopamine receptor radioligands to increased synaptic dopamine.

    Science.gov (United States)

    Gatley, S J; Gifford, A N; Carroll, F I; Volkow, N D

    2000-12-15

    PET and SPECT studies have documented that D2 radioligands of moderate affinity, but not radioligands of high affinity, are sensitive to pharmacological challenges that alter synaptic dopamine levels. The objective of this work was to determine whether the brain kinetics of high-affinity radioligands for dopamine D1 ([(3)H]SCH 23390) and D2 ([(123)I]epidepride) receptors were altered by a prolonged elevation of synaptic dopamine induced by the potent cocaine analog RTI-55. Mice were injected intravenously with radioligands either 30 min after or 4 h before intraperitoneal administration of RTI-55 (2 mg/kg). In separate experiments, the pharmacological effects of RTI-55 were assessed biochemically by measuring uptake of dopamine in synaptosomes prepared from RTI-treated mice and behaviorally by monitoring locomotor activity. Consistent with the expected elevation of synaptic dopamine, RTI-55 induced a long-lasting decrement in dopamine uptake measured ex vivo, and a prolonged increase in locomotor activity. RTI-55 injected prior to the radioligands induced a significant (P epidepride at 15 min, relative to saline-treated controls, but there were no differences between the two groups at later time-points. For [(3)H]SCH 23390, both initial striatal uptake and subsequent clearance were slightly increased by preadministration of RTI-55. Administration of RTI-55 4 h after the radioligands (i.e., when it was presumed that a state of near equilibrium binding of the radioligands had been reached), was associated with a significant reduction of striatal radioactivity for both radiotracers. Our results are consistent with increased competition between dopamine and radioligand for binding to both D1 and D2 receptors after treatment with RTI-55. We suggest that the magnitude of the competition is reduced by failure of the receptor binding of high-affinity radioligands to rapidly attain equilibrium. PMID:11044896

  7. Dopamine receptor activation increases HIV entry into primary human macrophages.

    Directory of Open Access Journals (Sweden)

    Peter J Gaskill

    Full Text Available Macrophages are the primary cell type infected with HIV in the central nervous system, and infection of these cells is a major component in the development of neuropathogenesis and HIV-associated neurocognitive disorders. Within the brains of drug abusers, macrophages are exposed to increased levels of dopamine, a neurotransmitter that mediates the addictive and reinforcing effects of drugs of abuse such as cocaine and methamphetamine. In this study we examined the effects of dopamine on HIV entry into primary human macrophages. Exposure to dopamine during infection increased the entry of R5 tropic HIV into macrophages, irrespective of the concentration of the viral inoculum. The entry pathway affected was CCR5 dependent, as antagonizing CCR5 with the small molecule inhibitor TAK779 completely blocked entry. The effect was dose-dependent and had a steep threshold, only occurring above 108 M dopamine. The dopamine-mediated increase in entry required dopamine receptor activation, as it was abrogated by the pan-dopamine receptor antagonist flupenthixol, and could be mediated through both subtypes of dopamine receptors. These findings indicate that the effects of dopamine on macrophages may have a significant impact on HIV pathogenesis. They also suggest that drug-induced increases in CNS dopamine may be a common mechanism by which drugs of abuse with distinct modes of action exacerbate neuroinflammation and contribute to HIV-associated neurocognitive disorders in infected drug abusers.

  8. Optical suppression of drug-evoked phasic dopamine release

    Directory of Open Access Journals (Sweden)

    James Edgar Mccutcheon

    2014-09-01

    Full Text Available Brief fluctuations in dopamine concentration (dopamine transients play a key role in behavior towards rewards, including drugs of abuse. Drug-evoked dopamine transients may result from actions at both dopamine cell bodies and dopamine terminals. Inhibitory opsins can be targeted to dopamine neurons permitting their firing activity to be suppressed. However, as dopamine transients can become uncoupled from firing, it is unknown whether optogenetic hyperpolarization at the level of the soma is able to suppress dopamine transients. Here, we used in vivo fast-scan cyclic voltammetry to record transients evoked by cocaine and raclopride in nucleus accumbens (NAc of urethane-anesthetized rats. We targeted halorhodopsin (NpHR specifically to dopamine cells by injecting Cre-inducible virus into ventral tegmental area (VTA of transgenic rats that expressed Cre recombinase under control of the tyrosine hydroxylase promoter (TH-Cre+ rats. Consistent with previous work, co-administration of cocaine and raclopride led to the generation of dopamine transients in NAc shell. Illumination of VTA with laser strongly suppressed the frequency of transients in NpHR-expressing rats, but not in control rats. Laser did not have any effect on amplitude of transients. Thus, optogenetics can effectively reduce the occurrence of drug-evoked transients and is therefore a suitable approach for studying the functional role of such transients in drug-associated behavior.

  9. Bending analysis of laminated composite box beams

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, A.K.; Patel, H.J.; Pang, S.S. (Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Mechanical Engineering)

    1994-01-01

    Box beams are widely used in weight reduction structures such as aircraft wings. The use of composite box beams further reduces the weight factor for such structures with the same deflection and stress as that of isotropic box beams. The difference in the behavior of composite box beam with different fiber orientation, number of plies, and number of stringers also provides a wide range of designing parameters to achieve the required performance for a given problem. A bending analysis has been carried out for the study of deflections and stresses for box beams of different material (isotropic and laminated composites), size, and number of stringers subjected to different kinds of loading conditions. A finite element model has been developed based on the strain energy principle, and the results are compared with an available commercial code COSMOS/M.'' Experiments using aluminum and scotchply composite laminates were conducted to verify the results. An optimal design for size and number of stiffeners for a given loading condition has been achieved. Investigations have also been carried out to find the effect of transverse shear on the span-wise normal stress.

  10. Pharmacy Students’ Knowledge of Black Box Warnings

    Science.gov (United States)

    Shireman, Theresa I.; Generali, Joyce; Rigler, Sally; Mayorga, Angela

    2010-01-01

    Objective To evaluate the progression of pharmacy students’ knowledge of black box warnings across 3 years of didactic training, and to determine how they stay current with new warnings. Methods A cross-sectional survey instrument was administered to pharmacy students in their first (P1), second (P2), and third (P3) professional years. The survey assessed student awareness of medications possessing a black box warning and familiarity with the warning content for 20 medications (15 with and 5 without warnings). Results Mean number of correct responses identifying the presence or absence of a black box warning among the 20 medications were 5.8 ± 3.3, 9.6 ± 4.0, and 14.8 ± 2.8 for the P1, P2, and P3 students, respectively. Knowledge of black box warning content was variable. Students were least aware of the warning content for stavudine and enoxaparin. Students were most familiar with the warning content for paroxetine and estrogen. Conclusion Students’ awareness and understanding of black box warnings was proportional to their educational progression, but their knowledge level was inconsistent across drug groups. PMID:20221356

  11. Quantifying and comparing the pattern of thalamic and cortical projections to the posterior auditory field in hearing and deaf cats.

    Science.gov (United States)

    Butler, Blake E; Chabot, Nicole; Lomber, Stephen G

    2016-10-15

    Following sensory loss, compensatory crossmodal reorganization occurs such that the remaining modalities are functionally enhanced. For example, behavioral evidence suggests that peripheral visual localization is better in deaf than in normal hearing animals, and that this enhancement is mediated by recruitment of the posterior auditory field (PAF), an area that is typically involved in localization of sounds in normal hearing animals. To characterize the anatomical changes that underlie this phenomenon, we identified the thalamic and cortical projections to the PAF in hearing cats and those with early- and late-onset deafness. The retrograde tracer biotinylated dextran amine was deposited in the PAF unilaterally, to label cortical and thalamic afferents. Following early deafness, there was a significant decrease in callosal projections from the contralateral PAF. Late-deaf animals showed small-scale changes in projections from one visual cortical area, the posterior ectosylvian field (EPp), and the multisensory zone (MZ). With the exception of these minor differences, connectivity to the PAF was largely similar between groups, with the principle projections arising from the primary auditory cortex (A1) and the ventral division of the medial geniculate body (MGBv). This absence of large-scale connectional change suggests that the functional reorganization that follows sensory loss results from changes in synaptic strength and/or unmasking of subthreshold intermodal connections. J. Comp. Neurol. 524:3042-3063, 2016. © 2016 Wiley Periodicals, Inc. PMID:27019080

  12. The facilitatory influence of anterior cingulate cortex on ON-OFF response of tactile neuron in thalamic ventrobasal nucleus

    Institute of Scientific and Technical Information of China (English)

    曹晓华; 卢湘岳; 周绍慈

    2000-01-01

    The structures of limbic system have been found to modulate the auditory, visual and pain afferent signals in the related nuclei of thalamus. One of those structures is anterior cingulate cortex (ACC) that influences nocuous response of the pain-sensitive neurons in the ventropos-tero-lateral nucleus of thalamus. Thus, we inferred that ACC would also modulate tactile information at the thalamic level. To test this assumption, single units were recorded extracellularly from thalamic ventrobasal nucleus (VB). Tactile ON-OFF response and the relationship between different patterns of the responses and the parameters of tactile stimulation were examined. Furthermore, the influence of ACC on the tactile ON-OFF response was studied. ACC stimulation was found to produce a facilitatory effect on the OFF-response of ON-OFF neurons. It lowered the threshold of the off-response of that neuron, and therefore changed the response pattern or enhanced the firing rate of the OFF-response of the neuron. The study on rec

  13. The facilitatory influence of anterior cingulate cortex on ON-OFF response of tactile neuron in thalamic ventrobasal nucleus

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The structures of limbic system have been found to modulate the auditory, visual and pain afferent signals in the related nuclei of thalamus. One of those structures is anterior cingulate cortex (ACC) that influences nocuous response of the pain-sensitive neurons in the ventropostero-lateral nucleus of thalamus. Thus, we inferred that ACC would also modulate tactile information at the thalamic level. To test this assumption, single units were recorded extracellularly from thalamic ventrobasal nucleus (VB). Tactile ON-OFF response and the relationship between different patterns of the responses and the parameters of tactile stimulation were examined. Furthermore, the influence of ACC on the tactile ON-OFF response was studied. ACC stimulation was found to produce a facilitatory effect on the OFF-response of ON-OFF neurons. It lowered the threshold of the off-response of that neuron, and therefore changed the response pattern or enhanced the firing rate of the OFF-response of the neuron. The study on receptive fields of ON-OFF neurons showed that the excitation of the ACC could change an ON-response on the verge of a receptive field into an ON-OFF response. The above results suggest that the ACC modulation sharpens the response of a VB neuron to a moving stimulus within its receptive field, indicating that the limbic system can modulate tactile ascending sensory information.

  14. Engineering a thalamo-cortico-thalamic circuit on SpiNNaker: a preliminary study towards modelling sleep and wakefulness

    Directory of Open Access Journals (Sweden)

    Basabdatta Sen Bhattacharya

    2014-05-01

    Full Text Available We present a preliminary study of a thalamo-cortico-thalamic (TCT implementation on SpiNNaker (Spiking Neural Network architecture, a brain inspired hardware platform designed to incorporate the inherent biological properties of parallelism, fault tolerance and energy efficiency. These attributes make SpiNNaker an ideal platform for simulating biologically plausible computational models. Our focus in this work is to design a TCT framework that can be simulated on SpiNNaker to mimic dynamical behaviour similar to Electroencephalogram (EEG time and power-spectra signatures in sleep-wake transition. The scale of the model is minimised for simplicity in this proof-of-concept study; thus the total number of spiking neurons is approximately 1000 and represents a `mini-column' of the thalamocortical tissue. All data on model structure, synaptic layout and parameters is inspired from previous studies and abstracted at a level that is appropriate to the aims of the current study as well as computationally suitable for model simulation on a small 4-chip SpiNNaker system. The initial results from selective deletion of synaptic connectivity parameters in the model show similarity with EEG time series characteristics of sleep and wakefulness. These observations provide a positive perspective and a basis for future implementation of a very large scale biologically plausible model of thalamo-cortico-thalamic interactivity---the essential brain circuit that regulates the biological sleep-wake cycle and associated EEG rhythms.

  15. [Effect of dopamine on the portal pressure].

    Science.gov (United States)

    Benko, H; Peschl, L; Schüller, J; Neumayr, A

    1975-01-01

    1. An infusion of 3 gamma/kg/min dopamine causes a significant increase in the renal plasma flow and the glomerulum filtration rate. This dosage does not cause a change of the mean systolic and arterial pressure. This effect may also be observed in patients with hepatic cirrhosis. 2. The wedged hepatic vein pressure, an indicator for the portal pressure, only shows a slight increase (9,46 +/- 9,41%) as compared to the initial pressure produced by the mentioned dose. Measurements of the spleen pulpa pressure, which likewise indicates the portal pressure, showed an increase of pressure up to 100% due to pressing or coughing. 3. If in the case of bleeding oesophageal varices acute renal failure might develop, the advantage of the effect of dopamine in stimulating the blood flow through the kidneys may be considered more important than the minute danger of a slight increase of the portal pressure, which might provoke haemorrhage. PMID:1220517

  16. Social cognitive and neurocognitive deficits in inpatients with unilateral thalamic lesions — pilot study

    Directory of Open Access Journals (Sweden)

    Wilkos E

    2015-04-01

    Full Text Available Ewelina Wilkos,2 Timothy JB Brown,3 Ksenia Slawinska,1 Katarzyna A Kucharska2,3 1Department of Neurology, 2Department of Neuroses, Personality and Eating Disorders Institute of Psychiatry and Neurology, Warsaw, Poland; 3Department of Medical Education, Hull York Medical School, Hull, UK Background: The essential role of the thalamus in neurocognitive processes has been well documented. In contrast, relatively little is known about its involvement in social cognitive processes such as recognition of emotion, mentalizing, or empathy. The aim of the study: This study was designed to compare the performance of eight patients (five males, three females, mean age ± SD: 63.7±7.9 years at early stage of unilateral thalamic lesions and eleven healthy controls (six males, five females, 49.6±12.2 years in neurocognitive tests (CogState Battery: Groton Maze Learning Test, GML; Groton Maze Learning Test-Delayed Recall, GML-DR; Detection Task, DT; Identification Task, IT; One Card Learning Task, OCLT; One Back Task, OBT; Two Back Task, TBT; Set-Shifting Task, S-ST and other well-known tests (Benton Visual Retention Test, BVRT; California Verbal Learning Test, CVLT; The Rey-Osterrieth Complex Figure Test, ROCF; Trail Making Test, TMT part A and B; Color – Word Stroop Task, CWST; Verbal Fluency Test, VFT, and social cognitive tasks (The Penn Emotion Recognition Test, ER40; Penn Emotion Discrimination Task, EmoDiff40; The Penn Emotional Acuity Test, PEAT40; Reading the Mind in the Eyes Test, revised version II; Toronto Alexithymia Scale, TAS-20. Methods: Thalamic-damaged subjects were included if they experienced a single-episode ischemic stroke localized in right or left thalamus. The patients were examined at 3 weeks after the stroke onset. All were right handed. In addition, the following clinical scales were used: the Mini-Mental State Examination (MMSE, Spielberger State-Trait Anxiety Inventory (STAI, Beck Depression Inventory (BDI II. An inclusion

  17. Nearly Seamless Vacuum-Insulated Boxes

    Science.gov (United States)

    Stepanian, Christopher J.; Ou, Danny; Hu, Xiangjun

    2010-01-01

    A design concept, and a fabrication process that would implement the design concept, have been proposed for nearly seamless vacuum-insulated boxes that could be the main structural components of a variety of controlled-temperature containers, including common household refrigerators and insulating containers for shipping foods. In a typical case, a vacuum-insulated box would be shaped like a rectangular parallelepiped conventional refrigerator box having five fully closed sides and a hinged door on the sixth side. Although it is possible to construct the five-closed-side portion of the box as an assembly of five unitary vacuum-insulated panels, it is not desirable to do so because the relatively high thermal conductances of the seams between the panels would contribute significant amounts of heat leakage, relative to the leakage through the panels themselves. In contrast, the proposal would make it possible to reduce heat leakage by constructing the five-closed-side portion of the box plus the stationary portion (if any) of the sixth side as a single, seamless unit; the only remaining seam would be the edge seal around the door. The basic cross-sectional configuration of each side of a vacuum-insulated box according to the proposal would be that of a conventional vacuum-insulated panel: a low-density, porous core material filling a partially evacuated space between face sheets. However, neither the face sheets nor the core would be conventional. The face sheets would be opposite sides of a vacuum bag. The core material would be a flexible polymer-modified silica aerogel of the type described in Silica/Polymer and Silica/Polymer/Fiber Composite Aero - gels (MSC-23736) in this issue of NASA Tech Briefs. As noted in that article, the stiffness of this core material against compression is greater than that of prior aerogels. This is an important advantage because it translates to greater retention of thickness and, hence, of insulation performance when pressure is

  18. Advances in the theory of box integrals

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Borwein, J.M.; Crandall, R.E.

    2009-06-25

    Box integrals - expectations <|{rvec r}|{sup s}> or <|{rvec r}-{rvec q}|{sup s}> over the unit n-cube (or n-box) - have over three decades been occasionally given closed forms for isolated n,s. By employing experimental mathematics together with a new, global analytic strategy, we prove that for n {le} 4 dimensions the box integrals are for any integer s hypergeometrically closed in a sense we clarify herein. For n = 5 dimensions, we show that a single unresolved integral we call K{sub 5} stands in the way of such hyperclosure proofs. We supply a compendium of exemplary closed forms that naturally arise algorithmically from this theory.

  19. Trafficking of Dopamine Transporters in Psychostimulant Actions

    OpenAIRE

    Zahniser, Nancy R.; Sorkin, Alexander

    2009-01-01

    Brain dopamine (DA) plays a pivotal role in drug addiction. Since the plasma membrane DA transporter (DAT) is critical for terminating DA neurotransmission, it is important to understand how DATs are regulated and this regulation impacts drug addiction. The number of cell surface DATs is controlled by constitutive and regulated endocytic trafficking. Psychostimulants impact this trafficking. Amphetamines, DAT substrates, cause rapid up-regulation and slower down-regulation of DAT whereas coca...

  20. Dopamine Signaling in reward-related behaviors

    OpenAIRE

    Baik, Ja-Hyun

    2013-01-01

    Dopamine (DA) regulates emotional and motivational behavior through the mesolimbic dopaminergic pathway. Changes in DA mesolimbic neurotransmission have been found to modify behavioral responses to various environmental stimuli associated with reward behaviors. Psychostimulants, drugs of abuse, and natural reward such as food can cause substantial synaptic modifications to the mesolimbic DA system. Recent studies using optogenetics and DREADDs, together with neuron-specific or circuit-specifi...

  1. Dopamine Signaling in reward-related behaviors

    OpenAIRE

    Ja-Hyun Baik

    2013-01-01

    Dopamine (DA) regulates emotional and motivational behavior through the mesolimbic dopaminergic pathway. Changes in DAmesolimbic neurotransmission have been found to modify behavioral responses to various environmental stimuli associated with reward behaviors. Psychostimulants, drugs of abuse, and natural rewards such as food can cause substantial synaptic modifications to the mesolimbic DA system. Recent studies using optogenetics and DREADDs, together with neuron-specific or circuit-specifi...

  2. Dopamine Transporter Levels in Cocaine Dependent Subjects

    OpenAIRE

    Crits-Christoph, Paul; Newberg, Andrew; Wintering, Nancy; Ploessl, Karl; Gibbons, Mary Beth Connolly; RING-KURTZ, SARAH; Gallop, Robert; Present, Julie

    2008-01-01

    Cocaine use is a significant problem in the US and it is well established that cocaine binds to the dopamine transporter (DAT) in the brain. This study was designed to determine if the DAT levels measured by 99mTc TRODAT SPECT brain scans are altered in cocaine dependent subjects and to explore clinical correlates of such alterations. SPECT brain scans were acquired on 21 cocaine dependent subjects and 21 healthy matched controls. There were significantly higher DAT levels in cocaine dependen...

  3. The Evolution of Dopamine Systems in Chordates

    OpenAIRE

    Philippe Vernier

    2011-01-01

    Dopamine (DA) neurotransmission in the central nervous system (CNS) is found throughout chordates, and its emergence predates the divergence of chordates. Many of the molecular components of DA systems, such as biosynthetic enzymes, transporters, and receptors, are shared with those of other monoamine systems, suggesting the common origin of these systems. In the mammalian CNS, the DA neurotransmitter systems are diversified and serve for visual and olfactory perception, sensory–motor program...

  4. Response of Macroprolactinemia to Dopamine Agonists

    Directory of Open Access Journals (Sweden)

    Gonca Tamer

    2008-01-01

    Full Text Available Macroprolactinemia, defined as hyperprolactinemia with a predominance of the big big prolactin (macroprolactin isoform, is considered idiopathic and poorly symptomatic. Although macroprolactinemia has been considered to be a cause of apparent resistance to antiprolactinemic drugs, prolactin (PRL normalization with dopaminergic treatment cannot exclude macroprolactinemia.We report three cases with macroprolactinemia, whose PRL and macroprolactin levels were decreased and hyperprolactinemic symptoms were improved with dopamine agonists. Turk Jem 2008; 12: 83-5

  5. Dopamine Adsorption Configurations on Anatase (101) Surface

    Science.gov (United States)

    Stashans, Arvids; Marcillo, Freddy; Castillo, Darwin

    2015-05-01

    Present work is based on the density functional theory (DFT) and generalized gradient approximation studies. Different adsorption geometries of dopamine, C8H11O2N, on the anatase (101) surface have been considered and carefully investigated. Bidentate chelating configuration with two molecular oxygens binding to the same surface titanium has been found to be the equilibrium case. The Ti-O distances for this configuration are obtained to be equal to 2.23 and 2.37 Å, respectively.

  6. Fire test of DOT 7A Boxes

    International Nuclear Information System (INIS)

    The primary objective of conducting the full-scale fire tests of the DOT (Department of Transportation) 7A FRP Boxes was to provide information to assist in quantifying the fire hazard of the storage located at the Radioactive Waste Management Complex (RWMC), and to learn if changing the storage array will decrease the fire risk. Also, the level of fire fighting and fire protection required to maintain the risk at the RWMC within acceptable DOE guidelines was investigated. Two full-scale fire tests were conducted at Southwest Research Institute (SwRI) in June 1978, using the DOE 7A FRP Plywood Storage Containers. The fire tests showed that when subjected to a substantial ignition source, the boxes will propagate fire as long as no fire-suppression measures are taken. Fire will breach the boxes and spread the radioactive contaminated waste if it is not extinguished. As the fire progresses, additional boxes will become involved, and eventually the entire storage array will ignite. It is recommended that the use of DOT 7A Boxes be discontinued and replaced with noncombustible storage containers. In the event this is not practicable, guidance recommendations are presented to minimize the large fire loss potential. It is also recommended that an investigation be conducted into the number of boxes that can be destroyed and still maintain a safe environment for employees and the public. This investigation should include how far radioactive contamination will spread, what cleanup will be required, anticipated exposure of the people within the area, and the public impact of such a fire

  7. Layered reward signalling through octopamine and dopamine in Drosophila

    OpenAIRE

    Burke, Christopher J.; Huetteroth, Wolf; Owald, David; Perisse, Emmanuel; Krashes, Michael J.; Das, Gaurav; Gohl, Daryl; Silies, Marion; Certel, Sarah; Waddell, Scott

    2012-01-01

    Dopamine is synonymous with reward and motivation in mammals. However, only recently has dopamine been linked to motivated behaviour and rewarding reinforcement in fruitflies. Instead, octopamine has historically been considered to be the signal for reward in insects. Here we show, using temporal control of neural function in Drosophila, that only short-term appetitive memory is reinforced by octopamine. Moreover, octopamine-dependent memory formation requires signalling through dopamine neur...

  8. Dopamine Uptake Changes Associated with Cocaine Self-Administration

    OpenAIRE

    Oleson, Erik B.; Talluri, Sanjay; Childers, Steven R; Smith, James E.; Roberts, David C.S.; Bonin, Keith D.; Budygin, Evgeny A.

    2008-01-01

    The present study was designed to reveal the relationship between cocaine-induced dopamine uptake changes and patterns of cocaine self-administration observed under a fixed ratio schedule. Cocaine was intravenously infused into anesthetized rats, according to inter-infusion intervals obtained from self-administering animals, and dopamine uptake changes (apparent Km ) were assessed in the nucleus accumbens using voltammetry. The data demonstrate that cocaine-induced dopamine transporter (DAT) ...

  9. Striatal dopamine and the interface between motivation and cognition

    OpenAIRE

    Aarts, E.; Holstein, M.G.A. van; Cools, R.

    2011-01-01

    Brain dopamine has long been known to be implicated in the domains of appetitive motivation and cognition. Recent work indicates that dopamine also plays a role in the interaction between appetitive motivation and cognition. Here we review this work. Animal work has revealed an arrangement of spiraling connections between the midbrain and the striatum that subserves a mechanism by which dopamine can direct information flow from ventromedial to more dorsal regions in the striatum. In line with...

  10. Striatal Dopamine and the Interface between Motivation and Cognition

    OpenAIRE

    EstherAarts; Miekevan Holstein

    2011-01-01

    Brain dopamine has long been known to be implicated in the domains of appetitive motivation and cognition. Recent work indicates that dopamine also plays a role in the interaction between appetitive motivation and cognition. Here we review this work. Animal work has revealed an arrangement of spiraling connections between the midbrain and the striatum that subserves a mechanism by which dopamine can direct information flow from ventromedial to more dorsal regions in the striatum. In line with...

  11. The dopamine transporter: role in neurotoxicity and human disease

    International Nuclear Information System (INIS)

    The dopamine transporter (DAT) is a plasma membrane transport protein expressed exclusively within a small subset of CNS neurons. It plays a crucial role in controlling dopamine-mediated neurotransmission and a number of associated behaviors. This review focuses on recent data elucidating the role of the dopamine transporter in neurotoxicity and a number of CNS disorders, including Parkinson disease, drug abuse, and attention deficit hyperactivity disorder (ADHD)

  12. Brain dopamine and kinematics of graphomotor functions.

    Science.gov (United States)

    Lange, Klaus W; Mecklinger, Lara; Walitza, Susanne; Becker, Georg; Gerlach, Manfred; Naumann, Markus; Tucha, Oliver

    2006-10-01

    Three experiments were performed in an attempt to achieve a better understanding of the effect of dopamine on handwriting. In the first experiment, kinematic aspects of handwriting movements were compared between healthy participants and patients with Parkinson's disease (PD) on their usual dopaminergic treatment and following withdrawal of dopaminergic medication. In the second experiment, the writing performance of healthy participants with a hyperechogenicity of the substantia nigra as detected by transcranial sonography (TCS) was compared with the performance of healthy participants with low echogenicity of the substantia nigra. The third experiment examined the effect of central dopamine reduction on kinematic aspects of handwriting movements in healthy adults using acute phenylalanine and tyrosine depletion (APTD). A digitising tablet was used for the assessment of handwriting movements. Participants were asked to perform a simple writing task. Movement time, distance, velocity, acceleration and measures of fluency of handwriting movements were measured. The kinematic analysis of handwriting movements revealed that alterations of central dopaminergic neurotransmission adversely affect movement execution during handwriting. In comparison to the automatic processing of handwriting movements displayed by control participants, participants with an altered dopaminergic neurotransmission shifted from an automatic to a controlled processing of movement execution. Central dopamine appears to be of particular importance with regard to the automatic execution of well-learned movements. PMID:16859791

  13. Dopamine and food addiction: lexicon badly needed.

    Science.gov (United States)

    Salamone, John D; Correa, Mercè

    2013-05-01

    Over the last few years, the concept of food addiction has become a common feature in the scientific literature, as well as the popular press. Nevertheless, the use of the term addiction to describe pathological aspects of food intake in humans remains controversial, and even among those who affirm the validity of the concept, there is considerable disagreement about its utility for explaining the increasing prevalence of obesity throughout much of the world. An examination of the literature on food addiction indicates that mesolimbic and nigrostriatal dopamine systems often are cited as mechanisms that contribute to the establishment of food addiction. However, in reviewing this literature, it is important to have a detailed consideration of the complex nature of dopaminergic involvement in motivational processes. For example, although it is often stated that mesolimbic dopamine mediates reward, there is no standard or consistent technical meaning of this term. Moreover, there is a persistent tendency to link dopamine transmission with pleasure or hedonia, as opposed to other aspects of motivation or learning. The present article provides a critical discussion of some aspects of the food addiction literature, viewed through the lens of recent findings and current theoretical views of dopaminergic involvement in food motivation. Furthermore, compulsive food intake and binge eating will be considered from an evolutionary perspective, in terms of the motivational subsystems that are involved in adaptive patterns of food consumption and seeking behaviors and a consideration of how these could be altered in pathological conditions. PMID:23177385

  14. Testing of packings for stuffing boxes

    International Nuclear Information System (INIS)

    The stuffing box packings function when they are sealed tight and do not obstruct the movement of the spindle. Characteristic values are necessary to characterise the materials properties of stuffing box packings. Essentially, the definitions of the characteristic values are known and can be calculated in experimental setups. It is absolutely necessary to standardise the characteristic values as well as the testing procedures in order to be able to provide comparable and reproduceable characteristic values. Depending upon the importance of the fittings, it is necessary to guarantee sufficiently exact and reliable assembly for defined operating conditions. (orig.)

  15. Atypical Dopamine Uptake Inhibitors that Provide Clues About Cocaine's Mechanism at the Dopamine Transporter

    Science.gov (United States)

    Hauck Newman, Amy; Katz, Jonathan L.

    The dopamine transporter (DAT) has been a primary target for cocaine abuse/addiction medication discovery. However predicted addiction liability and limited clinical evaluation has provided a formidable challenge for development of these agents for human use. The unique and atypical pharmacological profile of the benztropine (BZT) class of dopamine uptake inhibitors, in preclinical models of cocaine effects and abuse, has encouraged further development of these agents. Moreover, in vivo studies have challenged the original DAT hypothesis and demonstrated that DAT occupancy and subsequent increases in dopamine produced by BZT analogues are significantly delayed and long lasting, as compared to cocaine. These important and distinctive elements are critical to the lack of abuse liability among BZT analogues, and improve their potential for development as treatments for cocaine abuse and possibly other neuropsychiatric disorders.

  16. Influence of phasic and tonic dopamine release on receptor activation

    DEFF Research Database (Denmark)

    Dreyer, Jakob Kristoffer Kisbye; Herrik, Kjartan F; Berg, Rune W; Hounsgaard, Jørn D

    2010-01-01

    Tonic and phasic dopamine release is implicated in learning, motivation, and motor functions. However, the relationship between spike patterns in dopaminergic neurons, the extracellular concentration of dopamine, and activation of dopamine receptors remains unresolved. In the present study, we...... develop a computational model of dopamine signaling that give insight into the relationship between the dynamics of release and occupancy of D(1) and D(2) receptors. The model is derived from first principles using experimental data. It has no free parameters and offers unbiased estimation of the...

  17. Several new imaging agents for central dopamine transporter

    International Nuclear Information System (INIS)

    123I-β-CIT (2β-carbomethoxy-3β-[4-iodophenyl]-tropane), a promising agent for imaging central dopamine transporter, has been successfully used in clinical and differential diagnosis and assessment of the magnitude of degeneration of nigra-striatum in Parkinson's disease. However, due to its poor selectivity for dopamine transporter and prolonged imaging interval (usually 20h after injection), and therefore limits its clinical use. Several new imaging agents have been developed for dopamine transporter in recent years, and significantly improved the characterization for imaging dopamine transporter

  18. Carbon Dot Based Sensing of Dopamine and Ascorbic Acid

    OpenAIRE

    Upama Baruah; Neelam Gogoi; Achyut Konwar; Manash Jyoti Deka; Devasish Chowdhury; Gitanjali Majumdar

    2014-01-01

    We demonstrate carbon dot based sensor of catecholamine, namely, dopamine and ascorbic acid. Carbon dots (CDs) were prepared from a green source: commercially available Assam tea. The carbon dots prepared from tea had particle sizes of ∼0.8 nm and are fluorescent. Fluorescence of the carbon dots was found to be quenched in the presence of dopamine and ascorbic acid with greater sensitivity for dopamine. The minimum detectable limits were determined to be 33 μM and 98 μM for dopamine and ascor...

  19. Cross-hemispheric dopamine projections have functional significance.

    Science.gov (United States)

    Fox, Megan E; Mikhailova, Maria A; Bass, Caroline E; Takmakov, Pavel; Gainetdinov, Raul R; Budygin, Evgeny A; Wightman, R Mark

    2016-06-21

    Dopamine signaling occurs on a subsecond timescale, and its dysregulation is implicated in pathologies ranging from drug addiction to Parkinson's disease. Anatomic evidence suggests that some dopamine neurons have cross-hemispheric projections, but the significance of these projections is unknown. Here we report unprecedented interhemispheric communication in the midbrain dopamine system of awake and anesthetized rats. In the anesthetized rats, optogenetic and electrical stimulation of dopamine cells elicited physiologically relevant dopamine release in the contralateral striatum. Contralateral release differed between the dorsal and ventral striatum owing to differential regulation by D2-like receptors. In the freely moving animals, simultaneous bilateral measurements revealed that dopamine release synchronizes between hemispheres and intact, contralateral projections can release dopamine in the midbrain of 6-hydroxydopamine-lesioned rats. These experiments are the first, to our knowledge, to show cross-hemispheric synchronicity in dopamine signaling and support a functional role for contralateral projections. In addition, our data reveal that psychostimulants, such as amphetamine, promote the coupling of dopamine transients between hemispheres. PMID:27298371

  20. [3H]dopamine release and dopamine receptor autoradiography in alcohol-preferring rats

    International Nuclear Information System (INIS)

    Full text: Given the reported importance of the A10 dopaminergic pathway in the reinforcement of many abused drugs, the objective of the present study was to examine the interaction of ethanol with dopamine neurotransmission, using an ethanol-preferring Fawn-Hooded (FH) strain of rats. [3H]Dopamine release was evoked from in vitro prisms of both FH and control Wistar-Kyoto (WKY) rat nucleus accumbens. KC1-stimulated [3H]dopamine release was reproducible, although S2/S1 ratios significantly differed between FH and WKY rats (FH 1.13±0.05, WKY 0.89±0.04, p3H]dopamine release was dependent on the presence of calcium ions, as demonstrated by the significant reduction in S2/S1 ratios upon calcium exclusion (FH 0.53±0.03, WKY 0.53±0.05> p2/D3-agonist quinpirole (1, 3 and 10μM). Ethanol (0.3, 1 and 3% υ/υ) potentiated the KC1-evoked release of [3H] dopamine in a concentration-related manner. Autoradiography was employed to quantify dopamine D1- and D2- binding site densities in the limbic system of FH and WKY rats. FH rats possessed a significantly higher density of D1- binding sites in the nucleus accumbens (FH 688±21, WKY 582±49 dpm/mm2; p<0.05, n=4). These findings suggest differences in central dopaminergic mechanisms may underlie alcohol seeking behaviour in FH rats. Copyright (1998) Australian Neuroscience Society

  1. Dopamine Transporters in Striatum Correlate with Deactivation in the Default Mode Network during Visuospatial Attention

    OpenAIRE

    Dardo Tomasi; Volkow, Nora D.; Ruiliang Wang; Frank Telang; Gene-Jack Wang; Linda Chang; Thomas Ernst; Fowler, Joanna S.

    2009-01-01

    BACKGROUND: Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain) are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN). Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation i...

  2. The selective detection of dopamine at a polypyrrole film doped with sulfonated β-cyclodextrins

    OpenAIRE

    Harley, Claire C.; Rooney, A. Denise; Breslin, Carmel B.

    2010-01-01

    A highly selective dopamine sensor was fabricated by doping polypyrrole with a sulfonated β-cyclodextrin. This composite material enabled the selective sensing of dopamine in the presence of a large excess of ascorbic acid and prevented the regeneration of dopamine through the homogeneous catalytic reaction of the ascorbate anion with the dopamine-o-quinone. A single redox wave, corresponding to the oxidation of dopamine, was observed in dopamine/ascorbate mixtures, giving a truly se...

  3. The role of the nucleus basalis of Meynert and reticular thalamic nucleus in pathogenesis of genetically determined absence epilepsy in rats : A lesion study

    NARCIS (Netherlands)

    Berdiev, R. K.; Chepurnov, S. A.; Veening, J. G.; Chepurnova, N. E.; van Luiftelaar, G.

    2007-01-01

    The role of cholinergic nucleus basalis (of Meynert) and the reticular thalamic nucleus in mechanisms of the generation spontaneous spike-and-wave discharges (SWDs) was investigated in the WAG/Rij rat model of absence epilepsy. Selective lesions were affected by local unilateral intraparenchymal inf

  4. Presence and function of dopamine transporter (DAT in stallion sperm: dopamine modulates sperm motility and acrosomal integrity.

    Directory of Open Access Journals (Sweden)

    Javier A Urra

    Full Text Available Dopamine is a catecholamine with multiple physiological functions, playing a key role in nervous system; however its participation in reproductive processes and sperm physiology is controversial. High dopamine concentrations have been reported in different portions of the feminine and masculine reproductive tract, although the role fulfilled by this catecholamine in reproductive physiology is as yet unknown. We have previously shown that dopamine type 2 receptor is functional in boar sperm, suggesting that dopamine acts as a physiological modulator of sperm viability, capacitation and motility. In the present study, using immunodetection methods, we revealed the presence of several proteins important for the dopamine uptake and signalling in mammalian sperm, specifically monoamine transporters as dopamine (DAT, serotonin (SERT and norepinephrine (NET transporters in equine sperm. We also demonstrated for the first time in equine sperm a functional dopamine transporter using 4-[4-(Dimethylaminostyryl]-N-methylpyridinium iodide (ASP(+, as substrate. In addition, we also showed that dopamine (1 mM treatment in vitro, does not affect sperm viability but decreases total and progressive sperm motility. This effect is reversed by blocking the dopamine transporter with the selective inhibitor vanoxerine (GBR12909 and non-selective inhibitors of dopamine reuptake such as nomifensine and bupropion. The effect of dopamine in sperm physiology was evaluated and we demonstrated that acrosome integrity and thyrosine phosphorylation in equine sperm is significantly reduced at high concentrations of this catecholamine. In summary, our results revealed the presence of monoamine transporter DAT, NET and SERT in equine sperm, and that the dopamine uptake by DAT can regulate sperm function, specifically acrosomal integrity and sperm motility.

  5. Methamphetamine produces bidirectional, concentration-dependent effects on dopamine neuron excitability and dopamine-mediated synaptic currents

    OpenAIRE

    Branch, Sarah Y.; Beckstead, Michael J.

    2012-01-01

    Amphetamine-like compounds are commonly used to enhance cognition and to treat attention deficit/hyperactivity disorder, but they also function as positive reinforcers and are self-administered at doses far exceeding clinical relevance. Many of these compounds (including methamphetamine) are substrates for dopamine reuptake transporters, elevating extracellular dopamine by inhibiting uptake and promoting reverse transport. This produces an increase in extracellular dopamine that inhibits dopa...

  6. Dopamine synapse is a neuroligin-2-mediated contact between dopaminergic presynaptic and GABAergic postsynaptic structures.

    Science.gov (United States)

    Uchigashima, Motokazu; Ohtsuka, Toshihisa; Kobayashi, Kazuto; Watanabe, Masahiko

    2016-04-12

    Midbrain dopamine neurons project densely to the striatum and form so-called dopamine synapses on medium spiny neurons (MSNs), principal neurons in the striatum. Because dopamine receptors are widely expressed away from dopamine synapses, it remains unclear how dopamine synapses are involved in dopaminergic transmission. Here we demonstrate that dopamine synapses are contacts formed between dopaminergic presynaptic and GABAergic postsynaptic structures. The presynaptic structure expressed tyrosine hydroxylase, vesicular monoamine transporter-2, and plasmalemmal dopamine transporter, which are essential for dopamine synthesis, vesicular filling, and recycling, but was below the detection threshold for molecules involving GABA synthesis and vesicular filling or for GABA itself. In contrast, the postsynaptic structure of dopamine synapses expressed GABAergic molecules, including postsynaptic adhesion molecule neuroligin-2, postsynaptic scaffolding molecule gephyrin, and GABAA receptor α1, without any specific clustering of dopamine receptors. Of these, neuroligin-2 promoted presynaptic differentiation in axons of midbrain dopamine neurons and striatal GABAergic neurons in culture. After neuroligin-2 knockdown in the striatum, a significant decrease of dopamine synapses coupled with a reciprocal increase of GABAergic synapses was observed on MSN dendrites. This finding suggests that neuroligin-2 controls striatal synapse formation by giving competitive advantage to heterologous dopamine synapses over conventional GABAergic synapses. Considering that MSN dendrites are preferential targets of dopamine synapses and express high levels of dopamine receptors, dopamine synapse formation may serve to increase the specificity and potency of dopaminergic modulation of striatal outputs by anchoring dopamine release sites to dopamine-sensing targets. PMID:27035941

  7. Cereal Box Design: An Interdisciplinary Graphics Activity

    Science.gov (United States)

    Fitzgerald, Mike; Tsosie, Teri

    2012-01-01

    The cereal box design activity is intriguing both for its simplicity and the resourcefulness that it can generate in young people. Also, it lends itself to a variety of curriculums. It covers both consumerism and Design for the Environment (DfE) concepts broadly and in depth. The activity introduces a wide range of topics. They include graphic…

  8. Study of WATCH GRB error boxes

    DEFF Research Database (Denmark)

    Gorosabel, J.; Castro-Tirado, A. J.; Lund, Niels;

    1995-01-01

    We have studied the first WATCH GRB Catalogue ofγ-ray Bursts in order to find correlations between WATCH GRB error boxes and a great variety of celestial objects present in 33 different catalogues. No particular class of objects has been found to be significantly correlated with the WATCH GRBs....

  9. Black hole formation in a box

    International Nuclear Information System (INIS)

    Evidence is presented for Hawking's viewpoint that in an insulated box in thermal equilibrium, black holes should form and evaporate in a statistically time-symmetric way. In particular, it is shown that if a black hole can evaporate adiabatically, it is much more likely to form adiabatically than by Jeans instability. (author)

  10. Safety evaluation for packaging CPC metal boxes

    International Nuclear Information System (INIS)

    This Safety Evaluation for Packaging (SEP) provides authorization for the use of Container Products Corporation (CPC) metal boxes, as described in this document, for the interarea shipment of radioactive contaminated equipment and debris for storage in the Central Waste Complex (CWC) or T Plant located in the 200 West Area. Authorization is granted until November 30, 1995. The CPC boxes included in this SEP were originally procured as US Department of Transportation (DOT) Specification 7A Type A boxes. A review of the documentation provided by the manufacturer revealed the documentation did not adequately demonstrate compliance to the 4 ft drop test requirement of 49 CFR 173.465(c). Preparation of a SEP is necessary to document the equivalent safety of the onsite shipment in lieu of meeting DOT packaging requirements until adequate documentation is received. The equivalent safety of the shipment is based on the fact that the radioactive contents consist of contaminated equipment and debris which are not dispersible. Each piece is wrapped in two layers of no less than 4 mil plastic prior to being placed in the box which has an additional 10 mil liner. Pointed objects and sharp edges are padded to prevent puncture of the plastic liner and wrapping

  11. Choreographies with Secure Boxes and Compromised Principals

    DEFF Research Database (Denmark)

    Carbone, Marco; Guttman, Joshua

      We equip choreography-level session descriptions with a simple abstraction of a security infrastruc- ture. Message components may be enclosed within (possibly nested) ”boxes” annotated with the intended source and destination of those components. The boxes are to be implemented with cryp...

  12. RELIABILITY BASED DESIGN OF A GEAR BOX

    Directory of Open Access Journals (Sweden)

    D.MADHUSEKHAR

    2014-08-01

    Full Text Available Reliability is the probability that a system, component or device will perform without failure for a specified period of time under specified operating conditions. The concept of reliability is of great importance in the design of various machine members. Conventional engineering design uses a deterministic approach. It disregards the fact that the material properties, the dimensions of the components and the externally applied loads are statistical in nature. In conventional design this uncertainties are covered with a factor of safety, which is not always successful. The growing trend towards reducing uncertainty and increasing reliability is to use the probabilistic approach. In the present work a three shaft four speed gear box and six speed gear box are designed using reliability principles. For the specified reliability of the system (Gear box, component reliability (Gear pair is calculated by considering the system as a series system. Design is considered to be safe and adequate if the probability of failure of gear box is less than or equal to a specified quantity in each of the two failure modes. . All the parameters affecting the design are considered as random variables and all the random variables are assumed to follow normal distribution. A computer program in C++ is developed to calculate the face widths in bending and surface failure modes. The larger one out of the two values is considered. By changing the variations in the design parameters, variations in the face widths are studied.

  13. Nondestructive assay of boxed radioactive waste

    International Nuclear Information System (INIS)

    This paper describes the problems related to the nondestructive assay (NDA) of boxed radioactive waste at the Hanford Site and how Westinghouse Hanford company (WHC) is solving the problems. The waste form and radionuclide content are described. The characteristics of the combined neutron and gamma-based measurement system are described

  14. A white box perspective on behavioural adaptation

    DEFF Research Database (Denmark)

    Bruni, Roberto; Corradini, Andrea; Gadducci, Fabio; Lluch Lafuente, Alberto; Vandin, Andrea

    We present a white-box conceptual framework for adaptation developed in the context of the EU Project ASCENS coordinated by Martin Wirsing. We called it CoDA, for Control Data Adaptation, since it is based on the notion of control data. CoDA promotes a neat separation between application and...

  15. PVC posting bags for glove boxes

    International Nuclear Information System (INIS)

    This specification covers the materials, measurements and manufacture of unpigmented PVC posting bags for use on glove boxes, together with methods of testing the materials. These bags are used in the handling of radioactive and toxic materials of a hazardous nature and therefore must be of the highest standard of mechanical strength, leak tightness and general finish. (author)

  16. Central actions of a novel and selective dopamine antagonist

    International Nuclear Information System (INIS)

    Receptors for the neurotransmitter dopamine traditionally have been divided into two subgroups: the D1 class, which is linked to the stimulation of adenylate cyclase-activity, and the D2 class which is not. There is much evidence suggesting that it is the D2 class which is not. There is much evidence suggesting that it is the D2 dopamine receptor that mediates the physiological and behavioral actions of dopamine in the intact animal. However, the benzazepine SCH23390 is a dopamine antagonist which has potent behavioral actions while displaying apparent neurochemical selectivity for the D1 class of dopamine receptors. The purpose of this dissertation was to (1) confirm and characterize this selectivity, and (2) test certain hypothesis related to possible modes of action of SCH233390. The inhibition of adenylate cyclase by SCH23390 occurred via an action at the dopamine receptor only. A radiolabeled analog of SCH23390 displayed the receptor binding properties of a specific high-affinity ligand, and regional receptor densities were highly correlated with dopamine levels. The subcellular distribution of [3H]-SCH23390 binding did not correspond completely with that of dopamine-stimulated adenylate cyclase. The neurochemical potency of SCH23390 as a D1 receptor antagonist was preserved following parental administration. A variety of dopamine agonists and antagonists displayed a high correlation between their abilities to compete for [3H]-SCH23390 binding in vitro and to act at an adenylate cyclase-linked receptor. Finally, the relative affinities of dopamine and SCH23390 for both D1 receptors and [3H]-SCH23390 binding sites were comparable. It is concluded that the behavioral effects of SCH23390 are mediated by actions at D1 dopamine receptors only, and that the physiological importance of this class of receptors should be reevaluated

  17. Responses of in vivo renal microvessels to dopamine.

    Science.gov (United States)

    Steinhausen, M; Weis, S; Fleming, J; Dussel, R; Parekh, N

    1986-09-01

    The split hydronephrotic kidney preparation was used to directly observe the effects of locally applied dopamine on the in vivo diameters of renal vessels. Dopamine (1 X 10(-6) to 3 X 10(-5) M) produced a concentration-dependent dilation of the arcuate and interlobular arteries and afferent arterioles. Efferent arterioles near the glomeruli also dilated to dopamine but the dilation was less than that of the preglomerular vessels. Higher dopamine concentrations (3 X 10(-4) and 1 X 10(-3) M) produced more variable effects, with a tendency for the arcuate and interlobular arteries and the afferent and efferent arterioles away from the glomeruli to decrease in diameter. After pretreatment with haloperidol, dopamine (1 X 10(-6) to 1 X 10(-4) M) did not dilate any pre- or postglomerular vascular segment, but the tendency for pre- and postglomerular constrictions with higher dopamine concentrations were not abolished. Pretreatment with phentolamine and propranolol enhanced the dilator response of the pre- and postglomerular vessels (except the afferent arterioles near glomeruli and efferent arterioles near welling points) to dopamine (3 X 10(-5) and 1 X 10(-4) M), and abolished the reductions in diameter produced by the high dopamine levels. These data indicate that the dilator effect of dopamine is mediated by interactions with specific dopaminergic receptors, while alpha and beta adrenergic receptors appear to mediate a constrictor influence observed with high dopamine concentrations. The overall effect of dopamine on the renal vessel diameters thus appears to depend on the balance of dilator and constrictor stimuli mediated by multiple receptors. PMID:3023735

  18. Anxiolytic effects of dopamine receptor ligands: I. Involvement of dopamine autoreceptors.

    Science.gov (United States)

    Bartoszyk, G D

    1998-01-01

    The anxiolytic-like properties of dopamine agonists and antagonists with different receptor profiles were investigated in the ultrasonic vocalization test in rats after subcutaneous administration. Only dopamine D2 receptor agonists inhibited ultrasonic vocalization with the following ED50 values: apomorphine (0.07 mg/kg), quinelorane (0.01 mg/kg), quinpirole (0.04 mg/kg), pramipexole (0.09 mg/kg), roxindole (0.04 mg/kg), talipexole (0.04 mg/kg), (+/-)-7-OH-DPAT (0.05 mg/kg), (+/-)-PPHT (0.03 mg/kg), (-)-TNPA (0.06 mg/kg), PD128907 (0.13 mg/kg). The D2 antagonists haloperidol, mazapertine, raclopride, remoxipride, L745870, U99194A, U101958 and S(-)-DS121, the partial agonists PD143188 and preclamol, the selective D1 agonist R(+)-SKF38393 and the D1 antagonist SCH23390, and the uptake inhibitors GBR12909, GBR12935 and indatraline lacked significant inhibitory effects on ultrasonic vocalization. Because at least some of the D2 receptor agonists investigated have selectivity for dopamine autoreceptors, it is speculated that the dopamine autoreceptor may be a target for the development of new antianxiety drugs. PMID:9472724

  19. Functional potencies of dopamine agonists and antagonists at human dopamine D₂ and D₃ receptors.

    Science.gov (United States)

    Tadori, Yoshihiro; Forbes, Robert A; McQuade, Robert D; Kikuchi, Tetsuro

    2011-09-01

    We measured the functional agonist potencies of dopamine agonists including antiparkinson drugs, and functional antagonist potencies of antipsychotics at human dopamine D(2) and D(3) receptors. In vitro pharmacological assessment included inhibition of forskolin-stimulated cAMP accumulation and the reversal of dopamine-induced inhibition in clonal Chinese hamster ovary cells expressing low and high densities of human dopamine D(2L) and D(2S) receptors (hD(2L)-Low, hD(2L)-High, hD(2S)-Low and hD(2S)-High, respectively) and human dopamine D(3) Ser-9 and D(3) Gly-9 receptors (hD(3)-Ser-9 and hD(3)-Gly-9, respectively). Cabergoline, bromocriptine, pergolide, (±)-7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT), talipexole, pramipexole, R-(+)-trans-3,4,4a,10b-tetrahydro-4-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-olhydrochloride (PD128907) and ropinirole behaved as dopamine D(2) and D(3) receptor full agonists and showed higher potencies in hD(2L)-High and hD(2S)-High compared to hD(2L)-Low and hD(2S)-Low. In hD(3)-Ser-9 and hD(3)-Gly-9 compared to hD(2L)-Low and hD(2S)-Low, dopamine, ropinirole, PD128907, and pramipexole potencies were clearly higher; talipexole and 7-OH-DPAT showed slightly higher potencies; pergolide showed slightly lower potency; and, cabergoline and bromocriptine potencies were lower. Aripiprazole acted as an antagonist in hD(2L)-Low; a low intrinsic activity partial agonist in hD(2S)-Low; a moderate partial agonist in hD(3)-Ser-9 and hD(3)-Gly-9; a robust partial agonist in hD(2L)-High; and a full agonist in hD(2S)-High. Amisulpride, sulpiride and perphenazine behaved as preferential antagonists; and chlorpromazine and asenapine behaved as modest preferential antagonists; whereas fluphenazine, haloperidol, and blonanserin behaved as non-preferential antagonists in hD(2S)-Low and hD(2S)-High compared to hD(3)-Ser-9 and hD(3)-Gly-9. These findings may help to elucidate the basis of therapeutic benefit observed with these drugs, with

  20. Increased expression of the dopamine transporter leads to loss of dopamine neurons, oxidative stress and l-DOPA reversible motor deficits.

    Science.gov (United States)

    Masoud, S T; Vecchio, L M; Bergeron, Y; Hossain, M M; Nguyen, L T; Bermejo, M K; Kile, B; Sotnikova, T D; Siesser, W B; Gainetdinov, R R; Wightman, R M; Caron, M G; Richardson, J R; Miller, G W; Ramsey, A J; Cyr, M; Salahpour, A

    2015-02-01

    The dopamine transporter is a key protein responsible for regulating dopamine homeostasis. Its function is to transport dopamine from the extracellular space into the presynaptic neuron. Studies have suggested that accumulation of dopamine in the cytosol can trigger oxidative stress and neurotoxicity. Previously, ectopic expression of the dopamine transporter was shown to cause damage in non-dopaminergic neurons due to their inability to handle cytosolic dopamine. However, it is unknown whether increasing dopamine transporter activity will be detrimental to dopamine neurons that are inherently capable of storing and degrading dopamine. To address this issue, we characterized transgenic mice that over-express the dopamine transporter selectively in dopamine neurons. We report that dopamine transporter over-expressing (DAT-tg) mice display spontaneous loss of midbrain dopamine neurons that is accompanied by increases in oxidative stress markers, 5-S-cysteinyl-dopamine and 5-S-cysteinyl-DOPAC. In addition, metabolite-to-dopamine ratios are increased and VMAT2 protein expression is decreased in the striatum of these animals. Furthermore, DAT-tg mice also show fine motor deficits on challenging beam traversal that are reversed with l-DOPA treatment. Collectively, our findings demonstrate that even in neurons that routinely handle dopamine, increased uptake of this neurotransmitter through the dopamine transporter results in oxidative damage, neuronal loss and l-DOPA reversible motor deficits. In addition, DAT over-expressing animals are highly sensitive to MPTP-induced neurotoxicity. The effects of increased dopamine uptake in these transgenic mice could shed light on the unique vulnerability of dopamine neurons in Parkinson's disease. PMID:25447236

  1. Nucleus accumbens dopamine receptors in the consolidation of spatial memory.

    NARCIS (Netherlands)

    Mele, A.; Avena, M.; Roullet, P.; Leonibus, E. de; Mandillo, S.; Sargolini, F.; Coccurello, R.; Oliverio, A.

    2004-01-01

    Nucleus accumbens dopamine is known to play an important role in motor activity and in behaviours governed by drugs and natural reinforcers, as well as in non-associative forms of learning. At the same time, activation of D1 and D2 dopamine receptors has been suggested to promote intracellular event

  2. Striatal dopamine and the interface between motivation and cognition

    NARCIS (Netherlands)

    Aarts, E.; Holstein, M.G.A. van; Cools, R.

    2011-01-01

    Brain dopamine has long been known to be implicated in the domains of appetitive motivation and cognition. Recent work indicates that dopamine also plays a role in the interaction between appetitive motivation and cognition. Here we review this work. Animal work has revealed an arrangement of spiral

  3. Mesolimbic dopamine and its neuromodulators in obesity and binge eating.

    Science.gov (United States)

    Naef, Lindsay; Pitman, Kimberley A; Borgland, Stephanie L

    2015-12-01

    Obesity has reached epidemic prevalence, and much research has focused on homeostatic and nonhomeostatic mechanisms underlying overconsumption of food. Mesocorticolimbic circuitry, including dopamine neurons of the ventral tegmental area (VTA), is a key substrate for nonhomeostatic feeding. The goal of the present review is to compare changes in mesolimbic dopamine function in human obesity with diet-induced obesity in rodents. Additionally, we will review the literature to determine if dopamine signaling is altered with binge eating disorder in humans or binge eating modeled in rodents. Finally, we assess modulation of dopamine neurons by neuropeptides and peripheral peptidergic signals that occur with obesity or binge eating. We find that while decreased dopamine concentration is observed with obesity, there is inconsistency outside the human literature on the relationship between striatal D2 receptor expression and obesity. Finally, few studies have explored how orexigenic or anorexigenic peptides modulate dopamine neuronal activity or striatal dopamine in obese models. However, ghrelin modulation of dopamine neurons may be an important factor for driving binge feeding in rodents. PMID:26514168

  4. Bilingual language processing after a lesion in the left thalamic and temporal regions. A case report with early childhood onset

    International Nuclear Information System (INIS)

    This case study concerns an 18-year-old bilingual girl who suffered a radiation lesion in the left (dominant) thalamic and temporal region when she was 4 years old. Language and memory assessment revealed deficits in auditory short-term memory, auditory word comprehension, nonword repetition, syntactic processing, word fluency, and confrontation naming tasks. Both languages (English and Dutch) were found to be affected in a similar manner, despite the fact that one language (English) was acquired before and the other (Dutch) after the period of lesion onset. Most of the deficits appear to be related to verbal (short-term) memory dysfunction. Several hypotheses of subcortical involvement in memory processes are discussed with reference to existing theories in this area

  5. On the genesis of spike-wave oscillations in a mean-field model of human thalamic and corticothalamic dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Serafim [Department of Mathematical Sciences, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Terry, John R. [Department of Mathematical Sciences, Loughborough University, Leicestershire, LE11 3TU (United Kingdom)]. E-mail: j.r.terry@lboro.ac.uk; Breakspear, Michael [Black Dog Institute, Randwick, NSW 2031 (Australia); School of Psychiatry, UNSW, NSW 2030 (Australia)

    2006-07-10

    In this Letter, the genesis of spike-wave activity-a hallmark of many generalized epileptic seizures-is investigated in a reduced mean-field model of human neural activity. Drawing upon brain modelling and dynamical systems theory, we demonstrate that the thalamic circuitry of the system is crucial for the generation of these abnormal rhythms, observing that the combination of inhibition from reticular nuclei and excitation from the cortical signal, interplay to generate the spike-wave oscillation. The mechanism revealed provides an explanation of why approaches based on linear stability and Heaviside approximations to the activation function have failed to explain the phenomena of spike-wave behaviour in mean-field models. A mathematical understanding of this transition is a crucial step towards relating spiking network models and mean-field approaches to human brain modelling.

  6. On the genesis of spike-wave oscillations in a mean-field model of human thalamic and corticothalamic dynamics

    International Nuclear Information System (INIS)

    In this Letter, the genesis of spike-wave activity-a hallmark of many generalized epileptic seizures-is investigated in a reduced mean-field model of human neural activity. Drawing upon brain modelling and dynamical systems theory, we demonstrate that the thalamic circuitry of the system is crucial for the generation of these abnormal rhythms, observing that the combination of inhibition from reticular nuclei and excitation from the cortical signal, interplay to generate the spike-wave oscillation. The mechanism revealed provides an explanation of why approaches based on linear stability and Heaviside approximations to the activation function have failed to explain the phenomena of spike-wave behaviour in mean-field models. A mathematical understanding of this transition is a crucial step towards relating spiking network models and mean-field approaches to human brain modelling

  7. Dopamine modulates egalitarian behavior in humans.

    Science.gov (United States)

    Sáez, Ignacio; Zhu, Lusha; Set, Eric; Kayser, Andrew; Hsu, Ming

    2015-03-30

    Egalitarian motives form a powerful force in promoting prosocial behavior and enabling large-scale cooperation in the human species [1]. At the neural level, there is substantial, albeit correlational, evidence suggesting a link between dopamine and such behavior [2, 3]. However, important questions remain about the specific role of dopamine in setting or modulating behavioral sensitivity to prosocial concerns. Here, using a combination of pharmacological tools and economic games, we provide critical evidence for a causal involvement of dopamine in human egalitarian tendencies. Specifically, using the brain penetrant catechol-O-methyl transferase (COMT) inhibitor tolcapone [4, 5], we investigated the causal relationship between dopaminergic mechanisms and two prosocial concerns at the core of a number of widely used economic games: (1) the extent to which individuals directly value the material payoffs of others, i.e., generosity, and (2) the extent to which they are averse to differences between their own payoffs and those of others, i.e., inequity. We found that dopaminergic augmentation via COMT inhibition increased egalitarian tendencies in participants who played an extended version of the dictator game [6]. Strikingly, computational modeling of choice behavior [7] revealed that tolcapone exerted selective effects on inequity aversion, and not on other computational components such as the extent to which individuals directly value the material payoffs of others. Together, these data shed light on the causal relationship between neurochemical systems and human prosocial behavior and have potential implications for our understanding of the complex array of social impairments accompanying neuropsychiatric disorders involving dopaminergic dysregulation. PMID:25802148

  8. Neuroprotective changes of thalamic degeneration-related gene expression by acupuncture in an MPTP mouse model of parkinsonism: microarray analysis.

    Science.gov (United States)

    Yeo, Sujung; Choi, Yeong-Gon; Hong, Yeon-Mi; Lim, Sabina

    2013-02-25

    Acupuncture stimulations at GB34 and LR3 inhibit the reduction of tyrosine hydroxylase in the nigrostriatal dopaminergic neurons in the parkinsonism animal models. Especially, behavioral tests showed that acupuncture stimulations improved the motor dysfunction in a previous study by almost 87.7%. The thalamus is a crucial area for the motor circuit and has been identified as one of the most markedly damaged areas in Parkinson's disease (PD), so acupuncture stimulations might also have an effect on the thalamic damage. In this study, gene expression changes following acupuncture at the acupoints were investigated in the thalamus of a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism model using a whole transcript array. It was confirmed that acupuncture at these acupoints could inhibit the decrease of tyrosine hydroxylase in the thalamic regions of the MPTP model, while acupuncture at the non-acupoints could not suppress this decrease by its level shown in the acupoints. GeneChip gene array analysis showed that 18 (5 annotated genes: Dnase1l2, Dusp4, Mafg, Ndph and Pgm5) of the probes down-regulated in MPTP, as compared to the control, were exclusively up-regulated by acupuncture at the acupoints, but not at the non-acupoints. In addition, 14 (3 annotated genes; Serinc2, Sp2 and Ucp2) of the probes up-regulated in MPTP, as compared to the control, were exclusively down-regulated by acupuncture at the acupoints, but not at the non-acupoints. The expression levels of the representative genes in the microarray were validated by real-time RT-PCR. These results suggest that the 32 probes (8 annotated genes) which are affected by MPTP and acupuncture may be responsible for exerting the inhibitory effect of acupuncture in the thalamus which can be damaged by MPTP intoxication. PMID:23235115

  9. Effects of intravenous metamizole on ongoing and evoked activity of dura-sensitive thalamic neurons in rats.

    Science.gov (United States)

    Sokolov, Alexey Y; Lyubashina, Olga A; Sivachenko, Ivan B; Panteleev, Sergey S

    2014-05-15

    Migraine and tension-type headache (TTH) are the most common forms of primary headaches. A general key mechanism underlying development of both the diseases is the trigeminal system activation associated with the ascending nociceptive transmission via the trigemino-thalamo-cortical pathway. The ventroposteromedial (VPM) nucleus is a key thalamic structure, receiving afferent inflow from the craniofacial region; it holds the third-order neurons responsible for conveying sensory information from the extra- and intracranial nociceptors to the cortex. The VPM is currently seen as a therapeutic target for various antimigraine medications, which is shown to reduce the VPM neuronal excitability. A non-opioid analgesic metamizole is widely used in some countries for acute treatment of migraine or TTH. However, the precise mechanisms underlying anticephalgic action of metamizole remain unclear. The objective of our study performed in the rat model of trigemino-durovascular nociception was to evaluate the effects of intravenously administered metamizole on ongoing and evoked firing of the dura-sensitive VPM neurons. The experiments were carried out on rats under urethane-chloralose anesthesia. Cumulative administration of metamizole (thrice-repeated intravenous infusion of 150 mg/kg performed 30 min apart) in 56% of cases produced a suppression of both the ongoing activity of the thalamic VPM neurons and their responses to dural electrical stimulation. Although the inhibitory effect was prevailing, a number of VPM neurons were indifferent to the administration of metamizole. These data suggest that one of the main components of neural mechanism underlying anticephalgic action of metamizole is suppression of the thalamo-cortical nociceptive transmission associated with trigemino-vascular activation. PMID:24650732

  10. Dopamine D4 Receptors in Psychostimulant Addiction

    OpenAIRE

    Di Ciano, Patricia; Grandy, David; Le Foll, Bernard

    2014-01-01

    Since the cloning of the D4 receptor in the 1990s, interest has been building in the role of this receptor in drug addiction, given the importance of dopamine in addiction. Like the D3 receptor, the D4 receptor has limited distribution within the brain suggesting it may have a unique role in drug abuse. However, compared to the D3 receptor, few studies have evaluated the importance of the D4 receptor. This may be due, in part, to the relative lack of compounds selective for the D4 receptor; t...

  11. Novos agonistas dopaminérgicos

    OpenAIRE

    MATTOS JAMES PITÁGORAS DE; MATTOS VÂNIA MARIA DE B. CORRÊA

    1999-01-01

    Apresentamos breve revisão da literatura sobre os agonistas dopaminérgicos. Referimos os cinco receptores conhecidos e onde estão localizados, as vantagens e as desvantagens de sua utilização nos pacientes com a doença de Parkinson.Introduzidos com o objetivo principal de controlar as limitações da levodopa, aumentando a janela terapêutica, analisamos a farmacocinética, a eficácia e os efeitos colaterais da cabergolina, do ropinirole e do pramipexole.

  12. A descending dopamine pathway conserved from basal vertebrates to mammals

    Science.gov (United States)

    Ryczko, Dimitri; Cone, Jackson J.; Alpert, Michael H.; Goetz, Laurent; Auclair, François; Dubé, Catherine; Parent, Martin; Roitman, Mitchell F.; Alford, Simon; Dubuc, Réjean

    2016-01-01

    Dopamine neurons are classically known to modulate locomotion indirectly through ascending projections to the basal ganglia that project down to brainstem locomotor networks. Their loss in Parkinson’s disease is devastating. In lampreys, we recently showed that brainstem networks also receive direct descending dopaminergic inputs that potentiate locomotor output. Here, we provide evidence that this descending dopaminergic pathway is conserved to higher vertebrates, including mammals. In salamanders, dopamine neurons projecting to the striatum or brainstem locomotor networks were partly intermingled. Stimulation of the dopaminergic region evoked dopamine release in brainstem locomotor networks and concurrent reticulospinal activity. In rats, some dopamine neurons projecting to the striatum also innervated the pedunculopontine nucleus, a known locomotor center, and stimulation of the dopaminergic region evoked pedunculopontine dopamine release in vivo. Finally, we found dopaminergic fibers in the human pedunculopontine nucleus. The conservation of a descending dopaminergic pathway across vertebrates warrants re-evaluating dopamine’s role in locomotion. PMID:27071118

  13. Grey-box modelling of pharmacokinetic/pharmacodynamic systems

    DEFF Research Database (Denmark)

    Tornøe, Christoffer Wenzel; Jacobsen, Judith L; Pedersen, Oluf;

    2004-01-01

    Grey-box pharmacokinetic/pharmacodynamic (PK/PD) modelling is presented as a promising way of modelling PK/PD systems. The concept behind grey-box modelling is based on combining physiological knowledge along with information from data in the estimation of model parameters. Grey-box modelling...

  14. 49 CFR 230.103 - Tender roller bearing journal boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Tender roller bearing journal boxes. 230.103... Locomotives and Tenders Running Gear § 230.103 Tender roller bearing journal boxes. Tender roller bearing journal boxes shall be maintained in a safe and suitable condition....

  15. 49 CFR 230.102 - Tender plain bearing journal boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Tender plain bearing journal boxes. 230.102... Locomotives and Tenders Running Gear § 230.102 Tender plain bearing journal boxes. Plain bearing journal boxes... expected to damage the bearing; or have a detrimental effect on the lubrication of the journal and...

  16. Application of Defense Technology Commonly Used in Boxing Match

    Institute of Scientific and Technical Information of China (English)

    Zhixiao Li[1; Jianjun Liu[2

    2015-01-01

    Boxing defense technology is a kind of techniques to prevent the opponent from attacking successfully. Boxing is a kind of sports that needs close cooperation between attack and defense. Attack is used for defense, where there is no attack, there will be no defense, and vice versa. Defense technology is the foundation of attack technology, therefore, defense is of vital importance in boxing match.

  17. Grey Box Modelling of Hydrological Systems

    DEFF Research Database (Denmark)

    Thordarson, Fannar Ørn

    intervals. The thesis illustrates three performance measures for this performance evaluations: reliability, sharpness and resolution. For decision making, a performance criterion is preferred that quantifies all of these measures in a single number, and for that the quantile skill score criterion is...... equations, and a black box model, which relates to models that are obtained statistically from input-output relations. Grey box model consists of a system description, defined by a finite set of stochastic differential equations, and an observation equation. Together, system and observation equations...... lack of fit in state space formulation, and further support decisions for a model expansion. By using stochastic differential equations to formulate the dynamics of the hydrological system, either the complexity of the model can be increased by including the necessary hydrological processes in the...

  18. Fatal exit the automotive black box debate

    CERN Document Server

    Kowalick, Tom

    2005-01-01

    "Fatal Exit: The Automotive Black Box Debate cuts through thirty years of political wrangling and institutional biases to provide an argument for the Motor Vehicle Event Data Recorder (MVEDR). This automotive equivalent of an airplane's flight recorder or black box is intended to solve the mysteries of car crashes and improve the safety of our roads. The reader is taken inside the automotive industry and the government highway safety establishment to foster an understanding of the politics and the positions on all sides of this safety debate. The author takes an unbiased approach, chronologically presenting each argument and uncovering the agendas and mandates of each of the stakeholders." "This publication is essential reading for all consumers who need to have their voices heard on this critical issue, as well as for attorneys, public safety advocates, public policy administrators, engineers, automotive professionals, journalists, and insurance executives."--Jacket.

  19. The Central Nervous System of Box Jellyfish

    DEFF Research Database (Denmark)

    Garm, Anders Lydik; Ekström, Peter

    2008-01-01

    nervous system is described. Each rhopalium holds a separate part of the CNS with 1,000 nerve cells and a large amount of neuropil. The rhopalial nervous system has several subsystems defined by the anatomy, location, and immunocytochemistry of the cells. Most of the subsystems connect to one or more of...... behaviors in the box jellyfish such as obstacle avoidance and navigation. The need to process the visual information and turn it into the appropriate behavior puts strong demands on the nervous system of box jellyfish, which appears more elaborate than in other cnidarians. Here, the central part of this...... the eye types, and it is likely that the rhopalial nervous system accounts for most of the visual processing. The major part of the CNS is made up of a ring nerve encircling the bell shaped body. The ring nerve holds around 10,000 cells and is directly connected to all four rhopalial nervous systems...

  20. The gradient flow in a twisted box

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Alberto [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2013-08-15

    We study the perturbative behavior of the gradient flow in a twisted box. We apply this information to define a running coupling using the energy density of the flow field. We study the step-scaling function and the size of cutoff effects in SU(2) pure gauge theory. We conclude that the twisted gradient flow running coupling scheme is a valid strategy for step-scaling purposes due to the relatively mild cutoff effects and high precision.

  1. Dry boxes and inert atmosphere techniques

    International Nuclear Information System (INIS)

    Practitioners need to conduct experiments with molten salts in an inert atmosphere owing to the chemical reactivity of these media. Most fused salt solvent systems show reactivity to water and/or oxygen, which results in significant chemical changes in the properties of these solvents. Although several studies on the nature of an oxygen/oxide electrode in this melt have been reported, the reactions have not been fully understood because of apparent water contamination in many cases. Nitrate melt systems are also hygroscopic; for example, the LiNO3-KNO3 eutectic (1770C) absorbs water to at least 0.2% by weight. The result is that the electrochemistry of heavier, electropositive metal ions has been significantly altered. In addition, trace amounts of water have been shown to significantly affect the oxygen-oxide redox chemistry in NaNO3-KNO3 melts (2500C). The haloaluminates, which include AlCl3-NaCl (1750C), as well as AlCl3-organic salt binaries are particularly sensitive to the presence of both oxygen and moisture. Oxygen is a strong oxidant in the fused hydroxide systems with formation of superoxide ion from either oxide or water. This chapter describes general, inert atmosphere techniques which can be used by the molten salt experimentalist. Because of the limitations of volatility, vacuum manipulations are not considered. Rather, the use of glove boxes, glove bags, and inert bench-top techniques are discussed. The areas covered are: glove box and bag equipment, operation and maintenance of glove boxes and glove bags, and common operations conducted inside glove boxes

  2. Adaptive Techniques to find Optimal Planar Boxes

    CERN Document Server

    Barbay, J; Pérez-Lantero, P

    2012-01-01

    Given a set $P$ of $n$ planar points, two axes and a real-valued score function $f()$ on subsets of $P$, the Optimal Planar Box problem consists in finding a box (i.e. axis-aligned rectangle) $H$ maximizing $f(H\\cap P)$. We consider the case where $f()$ is monotone decomposable, i.e. there exists a composition function $g()$ monotone in its two arguments such that $f(A)=g(f(A_1),f(A_2))$ for every subset $A\\subseteq P$ and every partition $\\{A_1,A_2\\}$ of $A$. In this context we propose a solution for the Optimal Planar Box problem which performs in the worst case $O(n^2\\lg n)$ score compositions and coordinate comparisons, and much less on other classes of instances defined by various measures of difficulty. A side result of its own interest is a fully dynamic \\textit{MCS Splay tree} data structure supporting insertions and deletions with the \\emph{dynamic finger} property, improving upon previous results [Cort\\'es et al., J.Alg. 2009].

  3. Changes in position and quality of preferred nest box: effects on nest box use by laying hens

    DEFF Research Database (Denmark)

    Riber, Anja Brinch; Nielsen, Birte L.

    2013-01-01

    Using laying hens, we investigated whether position of a nest box, both within the pen and relative to other nest boxes, influenced the preference for a nest box, and how a sudden and marked change to the preferred box influenced the use of nest boxes by the hens. Groups (n=12) of 15 Isa Warren...... hens were housed in pens, each with five identical nest boxes in different positions: Two single (in a corner or not) and a triplet of nest boxes (one of which in a corner). The use of nest boxes was determined by the number of eggs laid daily in each box. Three experiments, each lasting 10 days, were...... carried out. First, the undisturbed use of each of the nest box types was investigated, and a strong preference (P<0.001) was found for single nest boxes in a corner, with 62% of the nest box eggs laid there. Second, each of the hen groups was moved to another pen allocated at random, and where the...

  4. Elevated dopamine concentration in light-adapted zebrafish retinas is correlated with increased dopamine synthesis and metabolism.

    Science.gov (United States)

    Connaughton, Victoria P; Wetzell, Bradley; Arneson, Lynne S; DeLucia, Vittoria; Riley, Anthony L

    2015-10-01

    Probing zebrafish (Danio rerio) retinal cryostat sections, collected either 8 h into the light or dark cycle, with an antibody against tyrosine hydroxylase (TH) identified a single population of immunopositive cells in the inner retina. However, the observed labeling patterns were not identical in both sets of tissues - label intensity was brighter in light-adapted tissue. This difference was quantified by probing western blots of retinal homogenates with the same TH antibody, which showed that TH expression increased by 42% in light-adapted tissue. High-performance liquid chromatography with electrochemical detection revealed that the concentrations of both dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) are also elevated in light-adapted zebrafish retinal tissue. Dopamine levels increased by 14% and DOPAC levels increased by 25% when measured in retinal homogenates harvested during the light cycle. These results indicate that dopamine levels in zebrafish retina are significantly increased in light-adapted tissue. The increase in dopamine content is correlated with an increase in both TH and DOPAC, suggesting that changes in dopamine concentration are due to light-adaptive changes in the synthesis, release and metabolism of dopamine. Dopamine concentration is elevated in lighted-adapted zebrafish retinas. This increase is correlated with an increase in both tyrosine hydroxylase (TH) and DOPAC (3,4-dihydroxyphenylacetic acid), suggesting that changes in dopamine concentration are due to light-adaptive changes in the synthesis, release and metabolism of dopamine. This is applicable to studies examining retinal mutants, the role of dopamine in disease or visual system development. PMID:26212704

  5. Stimulus-Dependent Dopamine Release in Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Sikstrom, Sverker; Soderlund, Goran

    2007-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is related to an attenuated and dysfunctional dopamine system. Normally, a high extracellular dopamine level yields a tonic dopaminergic input that down-regulates stimuli-evoked phasic dopamine responses through autoreceptors. Abnormally low tonic extracellular dopamine in ADHD up-regulates the…

  6. Business plan PME.Box: internationalization to Spain

    OpenAIRE

    Pinto, Diogo José Gomes Ferreira

    2011-01-01

    The document herein described, provides detailed information of the development of PME.BOX Business Plan regarding the expansion to a detailed overview of the business model and strategies that PME.BOX looks to implement in order to maximize its business reach and in turn generate revenue. PME.BOX (firm) is an IT start up firm based in Madan Par the commercial rights of pme.box (software). Pme.box is a touch management solution intended to help small and medium enterprises (SMEs) in ...

  7. Dopamine D2-like receptor signaling suppresses human osteoclastogenesis.

    Science.gov (United States)

    Hanami, Kentaro; Nakano, Kazuhisa; Saito, Kazuyoshi; Okada, Yosuke; Yamaoka, Kunihiro; Kubo, Satoshi; Kondo, Masahiro; Tanaka, Yoshiya

    2013-09-01

    Dopamine, a major neurotransmitter, transmits signals via five different seven-transmembrane G protein-coupled receptors termed D1 to D5. Although the relevance of neuroendocrine system to bone metabolism has been emerging, the precise effects of dopaminergic signaling upon osteoclastogenesis remain unknown. Here, we demonstrate that human monocyte-derived osteoclast precursor cells express all dopamine-receptor subtypes. Dopamine and dopamine D2-like receptor agonists such as pramipexole and quinpirole reduced the formation of TRAP-positive multi-nucleated cells, cathepsin K mRNA expression, and pit formation area in vitro. These inhibitory effects were reversed by pre-treatment with a D2-like receptor antagonist haloperidol or a Gαi inhibitor pertussis toxin, but not with the D1-like receptor antagonist SCH-23390. Dopamine and dopamine D2-like receptor agonists, but not a D1-like receptor agonist, suppressed intracellular cAMP concentration as well as RANKL-meditated induction of c-Fos and NFATc1 mRNA expression in human osteoclast precursor cells. Finally, the dopamine D2-like receptor agonist suppressed LPS-induced osteoclast formation in murine bone marrow culture ex vivo. These findings indicate that dopaminergic signaling plays an important role in bone homeostasis via direct effects upon osteoclast differentiation and further suggest that the clinical use of neuroleptics is likely to affect bone mass. PMID:23631878

  8. The Neurotropic Parasite Toxoplasma Gondii Increases Dopamine Metabolism

    Science.gov (United States)

    Prandovszky, Emese; Gaskell, Elizabeth; Martin, Heather; Dubey, J. P.; Webster, Joanne P.; McConkey, Glenn A.

    2011-01-01

    The highly prevalent parasite Toxoplasma gondii manipulates its host's behavior. In infected rodents, the behavioral changes increase the likelihood that the parasite will be transmitted back to its definitive cat host, an essential step in completion of the parasite's life cycle. The mechanism(s) responsible for behavioral changes in the host is unknown but two lines of published evidence suggest that the parasite alters neurotransmitter signal transduction: the disruption of the parasite-induced behavioral changes with medications used to treat psychiatric disease (specifically dopamine antagonists) and identification of a tyrosine hydroxylase encoded in the parasite genome. In this study, infection of mammalian dopaminergic cells with T. gondii enhanced the levels of K+-induced release of dopamine several-fold, with a direct correlation between the number of infected cells and the quantity of dopamine released. Immunostaining brain sections of infected mice with dopamine antibody showed intense staining of encysted parasites. Based on these analyses, T. gondii orchestrates a significant increase in dopamine metabolism in neural cells. Tyrosine hydroxylase, the rate-limiting enzyme for dopamine synthesis, was also found in intracellular tissue cysts in brain tissue with antibodies specific for the parasite-encoded tyrosine hydroxylase. These observations provide a mechanism for parasite-induced behavioral changes. The observed effects on dopamine metabolism could also be relevant in interpreting reports of psychobehavioral changes in toxoplasmosis-infected humans. PMID:21957440

  9. The neurotropic parasite Toxoplasma gondii increases dopamine metabolism.

    Directory of Open Access Journals (Sweden)

    Emese Prandovszky

    Full Text Available The highly prevalent parasite Toxoplasma gondii manipulates its host's behavior. In infected rodents, the behavioral changes increase the likelihood that the parasite will be transmitted back to its definitive cat host, an essential step in completion of the parasite's life cycle. The mechanism(s responsible for behavioral changes in the host is unknown but two lines of published evidence suggest that the parasite alters neurotransmitter signal transduction: the disruption of the parasite-induced behavioral changes with medications used to treat psychiatric disease (specifically dopamine antagonists and identification of a tyrosine hydroxylase encoded in the parasite genome. In this study, infection of mammalian dopaminergic cells with T. gondii enhanced the levels of K+-induced release of dopamine several-fold, with a direct correlation between the number of infected cells and the quantity of dopamine released. Immunostaining brain sections of infected mice with dopamine antibody showed intense staining of encysted parasites. Based on these analyses, T. gondii orchestrates a significant increase in dopamine metabolism in neural cells. Tyrosine hydroxylase, the rate-limiting enzyme for dopamine synthesis, was also found in intracellular tissue cysts in brain tissue with antibodies specific for the parasite-encoded tyrosine hydroxylase. These observations provide a mechanism for parasite-induced behavioral changes. The observed effects on dopamine metabolism could also be relevant in interpreting reports of psychobehavioral changes in toxoplasmosis-infected humans.

  10. Dopamine modulates metabolic rate and temperature sensitivity in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Taro Ueno

    Full Text Available Homeothermal animals, such as mammals, maintain their body temperature by heat generation and heat dissipation, while poikilothermal animals, such as insects, accomplish it by relocating to an environment of their favored temperature. Catecholamines are known to regulate thermogenesis and metabolic rate in mammals, but their roles in other animals are poorly understood. The fruit fly, Drosophila melanogaster, has been used as a model system for the genetic studies of temperature preference behavior. Here, we demonstrate that metabolic rate and temperature sensitivity of some temperature sensitive behaviors are regulated by dopamine in Drosophila. Temperature-sensitive molecules like dTrpA1 and shi(ts induce temperature-dependent behavioral changes, and the temperature at which the changes are induced were lowered in the dopamine transporter-defective mutant, fumin. The mutant also displays a preference for lower temperatures. This thermophobic phenotype was rescued by the genetic recovery of the dopamine transporter in dopamine neurons. Flies fed with a dopamine biosynthesis inhibitor (3-iodo-L-tyrosine, which diminishes dopamine signaling, exhibited preference for a higher temperature. Furthermore, we found that the metabolic rate is up-regulated in the fumin mutant. Taken together, dopamine has functions in the temperature sensitivity of behavioral changes and metabolic rate regulation in Drosophila, as well as its previously reported functions in arousal/sleep regulation.

  11. Dopamine uptake dynamics are preserved under isoflurane anesthesia.

    Science.gov (United States)

    Brodnik, Zachary D; España, Rodrigo A

    2015-10-01

    Fast scan cyclic voltammetry is commonly used for measuring the kinetics of dopamine release and uptake. For experiments using an anesthetized preparation, urethane is preferentially used because it does not alter dopamine uptake kinetics compared to freely moving animals. Unfortunately, urethane is highly toxic, can induce premature death during experiments, and cannot be used for recovery surgeries. Isoflurane is an alternative anesthetic that is less toxic than urethane, produces a stable level of anesthesia over extended periods, and is often used for recovery surgeries. Despite these benefits, the effects of isoflurane on dopamine release and uptake have not been directly characterized. In the present studies, we assessed the utility of isoflurane for voltammetry experiments by testing dopamine signaling parameters under baseline conditions, after treatment with the dopamine uptake inhibitor cocaine, and after exposure to increasing concentrations of isoflurane. Our results indicate that surgical levels of isoflurane do not significantly alter terminal mechanisms of dopamine release and uptake over prolonged periods of time. Consequently, we propose that isoflurane is an acceptable anesthetic for voltammetry experiments, which in turn permits the design of studies in which dopamine signaling is examined under anesthesia prior to recovery and subsequent experimentation in the same animals. PMID:26321152

  12. Maternal Immune Activation Disrupts Dopamine System in the Offspring

    Science.gov (United States)

    Luchicchi, Antonio; Lecca, Salvatore; Melis, Miriam; De Felice, Marta; Cadeddu, Francesca; Frau, Roberto; Muntoni, Anna Lisa; Fadda, Paola; Devoto, Paola

    2016-01-01

    Background: In utero exposure to maternal viral infections is associated with a higher incidence of psychiatric disorders with a supposed neurodevelopmental origin, including schizophrenia. Hence, immune response factors exert a negative impact on brain maturation that predisposes the offspring to the emergence of pathological phenotypes later in life. Although ventral tegmental area dopamine neurons and their target regions play essential roles in the pathophysiology of psychoses, it remains to be fully elucidated how dopamine activity and functionality are disrupted in maternal immune activation models of schizophrenia. Methods: Here, we used an immune-mediated neurodevelopmental disruption model based on prenatal administration of the polyriboinosinic-polyribocytidilic acid in rats, which mimics a viral infection and recapitulates behavioral abnormalities relevant to psychiatric disorders in the offspring. Extracellular dopamine levels were measured by brain microdialysis in both the nucleus accumbens shell and the medial prefrontal cortex, whereas dopamine neurons in ventral tegmental area were studied by in vivo electrophysiology. Results: Polyriboinosinic-polyribocytidilic acid-treated animals, at adulthood, displayed deficits in sensorimotor gating, memory, and social interaction and increased baseline extracellular dopamine levels in the nucleus accumbens, but not in the prefrontal cortex. In polyriboinosinic-polyribocytidilic acid rats, dopamine neurons showed reduced spontaneously firing rate and population activity. Conclusions: These results confirm that maternal immune activation severely impairs dopamine system and that the polyriboinosinic-polyribocytidilic acid model can be considered a proper animal model of a psychiatric condition that fulfills a multidimensional set of validity criteria predictive of a human pathology. PMID:26819283

  13. Role of dopamine in the pathogenesis of hypertension.

    Science.gov (United States)

    Jose, P A; Eisner, G M; Felder, R A

    1999-04-01

    1. Dopamine, via different dopamine receptor subtypes, regulates cardiovascular functions by actions on the central and peripheral nervous systems, vascular smooth muscle, the heart and the kidney. The dopaminergic system in the central nervous system (CNS) may participate in the regulation of systemic blood pressure. 2. Dopamine 'D2-like' (D2, D3 and D4) receptors, rather than 'D1-like' (D1 and D5) receptors, are involved in the CNS regulation of blood pressure; post-synaptic D2-like receptors increase blood pressure, while presynaptic D2-like receptors (the predominant action) produce the opposite effect. 3. Outside the CNS, dopamine may regulate blood pressure via pressure controls that act with intermediate rapidity (e.g. stress relaxation, arginine vasopressin and renin-angiotensin vasoconstriction), as well as those systems related to the long-term control of body fluid volume. 4. Dopamine D1- and D2-like receptors have been described in resistance vessels, such as the renal, mesenteric, coronary, pulmonary and cerebral arteries. The ability of D1-like receptors to inhibit renal smooth muscle hypertrophy indicates their importance in longer-term regulation of blood pressure. 5. Aberrant dopaminergic regulation of aldosterone secretion, via D2-like receptors, has been reported to be involved in some forms of hyperaldosteronism and hypertension. Some forms of hypertension may also be caused by an aberrant renal dopaminergic system. Abnormalities of three aspects of the renal dopaminergic system may lead to hypertension: (i) renal production of dopamine; (ii) transduction of the renal vascular dopamine signal; and (iii) transduction of the renal tubular dopamine signal. 6. Thus, increased blood pressure occurs after either blockade of D1-like receptors or of dopamine production in rats or disruption of the D1 receptor or the D3 receptor gene in mice. PMID:10386248

  14. Dopamine agonist withdrawal syndrome: implications for patient care.

    Science.gov (United States)

    Nirenberg, Melissa J

    2013-08-01

    Dopamine agonists are effective treatments for a variety of indications, including Parkinson's disease and restless legs syndrome, but may have serious side effects, such as orthostatic hypotension, hallucinations, and impulse control disorders (including pathological gambling, compulsive eating, compulsive shopping/buying, and hypersexuality). The most effective way to alleviate these side effects is to taper or discontinue dopamine agonist therapy. A subset of patients who taper a dopamine agonist, however, develop dopamine agonist withdrawal syndrome (DAWS), which has been defined as a severe, stereotyped cluster of physical and psychological symptoms that correlate with dopamine agonist withdrawal in a dose-dependent manner, cause clinically significant distress or social/occupational dysfunction, are refractory to levodopa and other dopaminergic medications, and cannot be accounted for by other clinical factors. The symptoms of DAWS include anxiety, panic attacks, dysphoria, depression, agitation, irritability, suicidal ideation, fatigue, orthostatic hypotension, nausea, vomiting, diaphoresis, generalized pain, and drug cravings. The severity and prognosis of DAWS is highly variable. While some patients have transient symptoms and make a full recovery, others have a protracted withdrawal syndrome lasting for months to years, and therefore may be unwilling or unable to discontinue DA therapy. Impulse control disorders appear to be a major risk factor for DAWS, and are present in virtually all affected patients. Thus, patients who are unable to discontinue dopamine agonist therapy may experience chronic impulse control disorders. At the current time, there are no known effective treatments for DAWS. For this reason, providers are urged to use dopamine agonists judiciously, warn patients about the risks of DAWS prior to the initiation of dopamine agonist therapy, and follow patients closely for withdrawal symptoms during dopamine agonist taper. PMID:23686524

  15. The binding sites for cocaine and dopamine in the dopamine transporter overlap

    DEFF Research Database (Denmark)

    Beuming, Thijs; Kniazeff, Julie; Bergmann, Marianne L; Shi, Lei; Gracia, Luis; Raniszewska, Klaudia; Newman, Amy Hauck; Javitch, Jonathan A; Weinstein, Harel; Gether, Ulrik; Løland, Claus Juul

    2008-01-01

    Cocaine is a widely abused substance with psychostimulant effects that are attributed to inhibition of the dopamine transporter (DAT). We present molecular models for DAT binding of cocaine and cocaine analogs constructed from the high-resolution structure of the bacterial transporter homolog Leu......T. Our models suggest that the binding site for cocaine and cocaine analogs is deeply buried between transmembrane segments 1, 3, 6 and 8, and overlaps with the binding sites for the substrates dopamine and amphetamine, as well as for benztropine-like DAT inhibitors. We validated our models by detailed...... mutagenesis and by trapping the radiolabeled cocaine analog [3H]CFT in the transporter, either by cross-linking engineered cysteines or with an engineered Zn2+-binding site that was situated extracellularly to the predicted common binding pocket. Our data demonstrate the molecular basis for the competitive...

  16. Evidence that Sleep Deprivation Downregulates Dopamine D2R in Ventral Striatum in the Human Brain

    OpenAIRE

    Volkow, Nora D.; Tomasi, Dardo; Wang, Gene-Jack; Telang, Frank; Fowler, Joanna S.; Logan, Jean; Benveniste, Helene; Kim, Ron; Thanos, Panayotis K.; Ferré, Sergi

    2012-01-01

    Dopamine D2 receptors are involved with wakefulness but their role in the decreased alertness associated with sleep deprivation is unclear. We had shown that sleep deprivation reduced dopamine D2/D3 receptor availability (measured with PET and [11C]raclopride in controls) in striatum, but could not determine if this reflected dopamine increases ([11C]raclopride competes with dopamine for D2/D3 receptor binding) or receptor downregulation. To clarify this, we compared the dopamine increases in...

  17. Classic Studies on the Interaction of Cocaine and the Dopamine Transporter

    OpenAIRE

    Verma, Vivek

    2015-01-01

    The dopamine transporter is responsible for recycling dopamine after release. Inhibitors of the dopamine transporter, such as cocaine, will stop the reuptake of dopamine and allow it to stay extracellularly, causing prominent changes at the molecular, cellular, and behavioral levels. There is much left to be known about the mechanism and site(s) of binding, as well as the effect that cocaine administration does to dopamine transporter-cocaine binding sites and gene expression which also plays...

  18. Characterization of Mouse Striatal Precursor Cell Lines Expressing Functional Dopamine Receptors

    OpenAIRE

    Araki, Kiyomi Y.; Fujimura, Satoshi; MacDonald, Marcy E.; Bhide, Pradeep G

    2006-01-01

    Dopamine and its receptors appear in the developing brain early in the embryonic period and dopamine receptor activation influences proliferation and differentiation of neuroepithelial precursor cells. Since dopamine D1 and D2 receptor activation produces opposing effects on precursor cell activity, dopamine's overall effects may correlate with relative numbers and activity of each receptor subtype on the precursor cells. Dopamine receptor expression and activity in individual precursor cells...

  19. Reconciling White-Box and Black-Box Perspectives on Behavioral Self-adaptation

    DEFF Research Database (Denmark)

    Bruni, Roberto; Corradini, Andrea; Gadducci, Fabio; Hölzl, Matthias; Lluch Lafuente, Alberto; Vandin, Andrea; Wirsing, Martin

    This paper proposes to reconcile two perspectives on behavioral adaptation commonly taken at different stages of the engineering of autonomic computing systems. Requirements engineering activities often take a black-box perspective: A system is considered to be adaptive with respect to an...... environment whenever the system is able to satisfy its goals irrespectively of the environment perturbations. Modeling and programming engineering activities often take a white-box perspective: A system is equipped with suitable adaptation mechanisms and its behavior is classified as adaptive depending on...... whether the adaptation mechanisms are enacted or not. The proposed approach reconciles black- and white-box perspectives by proposing several notions of coherence between the adaptivity as observed by the two perspectives: These notions provide useful criteria for the system developer to assess and...

  20. The binding sites for cocaine and dopamine in the dopamine transporter overlap

    OpenAIRE

    Beuming, Thijs; Kniazeff, Julie; Bergmann, Marianne L; Shi, Lei; Gracia, Luis; Raniszewska, Klaudia; Newman, Amy Hauck; Javitch, Jonathan A.; Weinstein, Harel; Gether, Ulrik; Loland, Claus J

    2008-01-01

    Cocaine is a widely abused substance with psychostimulant effects that are attributed to inhibition of the dopamine transporter (DAT). We present molecular models for DAT binding of cocaine and cocaine analogs constructed from the high-resolution structure of the bacterial transporter homolog LeuT. Our models suggest that the binding site for cocaine and cocaine analogs is deeply buried between transmembrane segments 1, 3, 6 and 8, and overlaps with the binding sites for the substrates dopami...

  1. Low or High Cocaine Responding Rats Differ in Striatal Extracellular Dopamine Levels and Dopamine Transporter Number

    OpenAIRE

    Nelson, Anna M.; Larson, Gaynor A.; Zahniser, Nancy R

    2009-01-01

    Both humans and animals exhibit marked individual differences in cocaine responsiveness. By using the median split of cocaine-induced locomotor activity, we have classified outbred male Sprague-Dawley rats as either low or high cocaine responders (LCRs or HCRs, respectively). LCR/HCR classification predicts differences in cocaine inhibition of striatal dopamine (DA) transporters (DATs), cocaine-induced locomotor sensitization, cocaine-conditioned place preference, and motivation to self-admin...

  2. Understanding dopamine and reinforcement learning: The dopamine reward prediction error hypothesis

    OpenAIRE

    Glimcher, Paul W.

    2011-01-01

    A number of recent advances have been achieved in the study of midbrain dopaminergic neurons. Understanding these advances and how they relate to one another requires a deep understanding of the computational models that serve as an explanatory framework and guide ongoing experimental inquiry. This intertwining of theory and experiment now suggests very clearly that the phasic activity of the midbrain dopamine neurons provides a global mechanism for synaptic modification. These synaptic modif...

  3. Dopamine-1 and dopamine-2 mechanisms in the control of renal function.

    Science.gov (United States)

    Carey, R M; Siragy, H M; Ragsdale, N V; Howell, N L; Felder, R A; Peach, M J; Chevalier, R L

    1990-06-01

    Dopamine (DA), a catecholamine produced in the kidney, is a renal vasodilator and natriuretic substance, but its action at dopamine-1 (DA-1), dopamine-2 (DA-2) and alpha- and beta-adrenergic receptors limits its effectiveness as a heuristic tool and pharmacologic agent. We have studied the effects of highly selective DA-1 and DA-2 receptor agonists and antagonists in normal human subjects and experimental animals to determine the precise physiological role of renal dopamine at DA-1 and DA-2 receptors within the kidney. We studied fenoldopam, a selective DA-1 agonist, in normal human subjects in metabolic balances at high (300 mEq/day) and low (10 mEq/day) sodium (Na) intake. Selective DA-1 receptor stimulation during high Na intake resulted in renal vasodilation, natriuresis and diuresis in a sustained manner for 3 hours. The natriuresis was mediated by a reduction in Na reabsorption at both proximal and distal tubular sites. In contrast, during low Na intake, DA-1 receptor stimulation did not engender a natriuretic or diuretic response. Thus, sodium depletion may inhibit the function of renal tubular cells in response to DA-1 stimulation. DA-1 receptors are present in the medial layer of the renal vasculature, proximal tubule and cortical collecting duct; DA-2 receptors are localized to the glomerulus, the renal nerves surrounding renal blood vessels and possibly the renal vascular endothelium. We have performed studies in conscious dogs with indwelling renal arterial catheters to identify the physiological role of renal DA to DA-1 and DA-2 receptors.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1974444

  4. Dopamine signaling in food addiction: role of dopamine D2 receptors

    OpenAIRE

    Ja-Hyun Baik

    2013-01-01

    Dopamine (DA) regulates emotional and motivational behavior through the mesolimbic dopaminergic pathway. Changes in DA signaling in mesolimbic neurotransmission are widely believed to modify reward-related behaviors and are therefore closely associated with drug addiction. Recent evidence now suggests that as with drug addiction, obesity with compulsive eating behaviors involves reward circuitry of the brain, particularly the circuitry involving dopaminergic neural substrates. Increasing amou...

  5. 49 CFR 178.512 - Standards for steel or aluminum boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for steel or aluminum boxes. 178.512... aluminum boxes. (a) The following are identification codes for steel or aluminum boxes: (1) 4A for a steel box; and (2) 4B for an aluminum box. (b) Construction requirements for steel or aluminum boxes are...

  6. Dopamine D3 receptor-preferring agonists induce neurotrophic effects on mesencephalic dopamine neurons.

    Science.gov (United States)

    Du, Fang; Li, Rui; Huang, Yuangui; Li, Xuping; Le, Weidong

    2005-11-01

    Anti-parkinsonian agents, pramipexole (PPX) and ropinirole (ROP), have been reported to possess neuroprotective properties, both in vitro and in vivo. The mechanisms underlying neuroprotection afforded by the D3-preferring receptor agonists remain poorly understood. The present study demonstrates that incubation of primary mesencephalic cultures with PPX and ROP or the conditioned medium from PPX- or ROP-treated primary cultures induced a marked increase in the number of dopamine (DA) neurons in the cultures. Similar effects can be observed after incubating with the conditioned medium derived from PPX- and ROP-treated substantia nigra astroglia. Meanwhile, PPX and ROP can protect the primary cells from insult of 1-methyl-4-phenylpyridinium (MPP+), the active metabolite of the neurotoxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP). Furthermore, the neurotrophic effects of PPX and ROP on mesencephalic dopamine neurons could be significantly blocked by D3 receptor antagonist, but not by D2 receptor antagonist. Moreover, we found that the levels of glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) in the conditioned medium of mesencephalic cultures treated with PPX and ROP were significantly increased. Blocking GDNF and BDNF with the neutralizing antibodies, the neurotrophic effects of PPX and ROP were greatly diminished. These results suggest that D3 dopamine receptor-preferring agonists, PPX and ROP, exert neurotrophic effects on cultured DA neurons by modulating the production of endogenous GDNF and BDNF, which may participate in their neuroprotection. PMID:16307585

  7. Effects of dexamphetamine-induced dopamine release on resting-state network connectivity in recreational amphetamine users and healthy controls.

    Science.gov (United States)

    Schrantee, Anouk; Ferguson, Bart; Stoffers, Diederick; Booij, Jan; Rombouts, Serge; Reneman, Liesbeth

    2016-06-01

    Dexamphetamine (dAMPH) is not only used for the treatment of attention deficit hyperactivity disorder (ADHD), but also as a recreational drug. Acutely, dAMPH induces release of predominantly dopamine (DA) in the striatum, and in the cortex both DA and noradrenaline. Recent animal studies have shown that chronic dAMPH administration can induce changes in the DA system following long-term exposure, as evidenced by reductions in DA transporters, D2/3 receptors and endogenous DA levels. However, only a limited number of studies have investigated the effects of dAMPH in the human brain. We used a combination of resting-state functional magnetic resonance imaging (rs-fMRI) and [(123)I]IBZM single-photon emission computed tomography (SPECT) (to assess baseline D2/3 receptor binding and DA release) in 15 recreational AMPH users and 20 matched healthy controls to investigate the short-, and long-term effects of AMPH before and after an acute intravenous challenge with dAMPH. We found that acute dAMPH administration reduced functional connectivity in the cortico-striatal-thalamic network. dAMPH-induced DA release, but not DA D2/3 receptor binding, was positively associated with connectivity changes in this network. In addition, acute dAMPH reduced connectivity in default mode networks and salience-executive-networks networks in both groups. In contrast to our hypothesis, no significant group differences were found in any of the rs-fMRI networks investigated, possibly due to lack of sensitivity or compensatory mechanisms. Our findings thus support the use of ICA-based resting-state functional connectivity as a tool to investigate acute, but not chronic, alterations induced by dAMPH on dopaminergic processing in the striatum. PMID:26149196

  8. Dopamine D3 receptor is decreased and D2 receptor is elevated in the striatum of Parkinson's disease.

    Science.gov (United States)

    Ryoo, H L; Pierrotti, D; Joyce, J N

    1998-09-01

    The mesolimbic dopamine (DA) system preferentially innervates the D3 receptor, whereas the D2 receptor is, in addition, a target of the nigrostriatal DA system. In human brain D3 receptors and D3 mRNA-expressing neurons are largely segregated to brain regions that are the targets of the mesolimbic DA system and the efferents of the "limbic striatum." Thus, D3 receptors may regulate effects of DA on the "limbic" cortico-striatal-pallidal-thalamic-cortical loop. The nigrostriatal DA system is considerably more damaged in Parkinson's disease (PD) than the mesolimbic DA system. We report here, using radioligands selective for the D2 and D3 receptor, that these receptors are independently changed in PD. Tissue collected at autopsy from nine subjects with a diagnosis of PD and eight age-matched subjects with no evidence of a neurologic disorder was processed for [125I]epidepride binding to D2 receptors, [125I] trans-7-OH-PIPAT binding to D3 receptors, [125I]RTI-55 for the DA transporter (DAT), and immunoautoradiography for tyrosine hydroxylase (TH) using autoradiographic methods. Dopaminergic innervation to the caudal putamen was profoundly reduced and to a lesser extent in the rostral putamen in PD. DAT sites but not TH protein levels were reduced in the nucleus accumbens (NAS) in PD compared with age-matched control subjects. This is consistent with a loss of dopaminergic innervation from the mesolimbic DA system but elevation in TH production. D3 receptors were significantly reduced in PD by 40-45% particularly in the NAS and putamen. D2 receptors were elevated in PD in the dorsal putamen by 15%. The reduction in D3 receptor number was not observed in PD cases with a diagnosis of less than 10 years. The changes in DA D3 receptor number is interesting in light of the development of antiparkinsonian agents that are D3-preferring agonists. PMID:9756147

  9. The Human Thalamic Somatic Sensory Nucleus [Ventral Caudal (Vc)] Shows Neuronal Mechanoreceptor-Like Responses to Optimal Stimuli for Peripheral Mechanoreceptors

    OpenAIRE

    Weiss, N.; Ohara, S.; Johnson, K. O.; Lenz, F. A.

    2008-01-01

    Although the response of human cutaneous mechanoreceptors to controlled stimuli is well studied, it is not clear how these peripheral signals may be reflected in neuronal activity of the human CNS. We now test the hypothesis that individual neurons in the human thalamic principal somatic sensory nucleus [ventral caudal (Vc)] respond selectively to the optimal stimulus for one of the four mechanoreceptors. The optimal stimuli for particular mechanoreceptors were defined as follows: Pacinian co...

  10. The Emotional Gatekeeper: A Computational Model of Attentional Selection and Suppression through the Pathway from the Amygdala to the Inhibitory Thalamic Reticular Nucleus.

    OpenAIRE

    Yohan J John; Basilis Zikopoulos; Daniel Bullock; Helen Barbas

    2016-01-01

    In a complex environment that contains both opportunities and threats, it is important for an organism to flexibly direct attention based on current events and prior plans. The amygdala, the hub of the brain's emotional system, is involved in forming and signaling affective associations between stimuli and their consequences. The inhibitory thalamic reticular nucleus (TRN) is a hub of the attentional system that gates thalamo-cortical signaling. In the primate brain, a recently discovered pat...

  11. Dopamine Signaling in reward-related behaviors

    Directory of Open Access Journals (Sweden)

    Ja-Hyun eBaik

    2013-10-01

    Full Text Available Dopamine (DA regulates emotional and motivational behavior through the mesolimbic dopaminergic pathway. Changes in DAmesolimbic neurotransmission have been found to modify behavioral responses to various environmental stimuli associated with reward behaviors. Psychostimulants, drugs of abuse, and natural rewards such as food can cause substantial synaptic modifications to the mesolimbic DA system. Recent studies using optogenetics and DREADDs, together with neuron-specific or circuit-specific genetic manipulations have improved our understanding of DA signaling in the reward circuit, and provided a means to identify the neural substrates of complex behaviors such as drug addiction and eating disorders. This review focuses on the role of the DA system in drug addiction and food motivation, with an overview of the role of D1 and D2 receptors in the control of reward-associated behaviors.

  12. Limbic thalamus and state-dependent behavior: The paraventricular nucleus of the thalamic midline as a node in circadian timing and sleep/wake-regulatory networks.

    Science.gov (United States)

    Colavito, Valeria; Tesoriero, Chiara; Wirtu, Amenu T; Grassi-Zucconi, Gigliola; Bentivoglio, Marina

    2015-07-01

    The paraventricular thalamic nucleus (PVT), the main component of the dorsal thalamic midline, receives multiple inputs from the brain stem and hypothalamus, and targets the medial prefrontal cortex, nucleus accumbens and amygdala. PVT has been implicated in several functions, especially adaptation to chronic stress, addiction behaviors and reward, mood, emotion. We here focus on the wiring and neuronal properties linking PVT with circadian timing and sleep/wake regulation, and their behavioral implications. PVT is interconnected with the master circadian pacemaker, the hypothalamic suprachiasmatic nucleus, receives direct and indirect photic input, is densely innervated by orexinergic neurons which play a key role in arousal and state transitions. Endowed with prominent wake-related Fos expression which is suppressed by sleep, and with intrinsic neuronal properties showing a diurnal oscillation unique in the thalamus, PVT could represent a station of interaction of thalamic and hypothalamic sleep/wake-regulatory mechanisms. PVT could thus play a strategic task by funneling into limbic and limbic-related targets circadian timing and state-dependent behavior information, tailoring it for cognitive performance and motivated behaviors. PMID:25479103

  13. Adaptation of Black-Box Software Components

    Directory of Open Access Journals (Sweden)

    Rolf Andreas Rasenack

    2008-01-01

    Full Text Available The globalization of the software market leads to crucial problems for software companies. More competition between software companies arises and leads to the force on companies to develop ever newer software products in ever shortened time interval. Therefore the time to market for software systems is shortened and obviously the product life cycle is shortened too. Thus software companies shortened the time interval for research and development. Due to the fact of competition between software companies software products have to develop low-priced and this leads to a smaller return on investment. A big challenge for software companies is the use of an effective research and development process to have these problems under control. A way to control these problems can be the reuse of existing software components and adapt those software components to new functionality or accommodate mismatched interfaces. Complete redevelopment of software products is more expensive and time consuming than to develop software components. The approach introduced here presents novel technique together with a supportive environment that enables developers to cope with the adaptability of black-box software components. A supportive environment will be designed that checks the compatibility of black-box software components with the assistance of their specifications. Generated adapter software components can take over the part of adaptation and advance the functionality. Besides, a pool of software components can be used to compose an application to satisfy customer needs. Certainly this pool of software components consists of black-box software components and adapter software components which can be connected on demand.

  14. Box codes of lengths 48 and 72

    Science.gov (United States)

    Solomon, G.; Jin, Y.

    1993-11-01

    A self-dual code length 48, dimension 24, with Hamming distance essentially equal to 12 is constructed here. There are only six code words of weight eight. All the other code words have weights that are multiples of four and have a minimum weight equal to 12. This code may be encoded systematically and arises from a strict binary representation of the (8,4;5) Reed-Solomon (RS) code over GF (64). The code may be considered as six interrelated (8,7;2) codes. The Mattson-Solomon representation of the cyclic decomposition of these codes and their parity sums are used to detect an odd number of errors in any of the six codes. These may then be used in a correction algorithm for hard or soft decision decoding. A (72,36;15) box code was constructed from a (63,35;8) cyclic code. The theoretical justification is presented herein. A second (72,36;15) code is constructed from an inner (63,27;16) Bose Chaudhuri Hocquenghem (BCH) code and expanded to length 72 using box code algorithms for extension. This code was simulated and verified to have a minimum distance of 15 with even weight words congruent to zero modulo four. The decoding for hard and soft decision is still more complex than the first code constructed above. Finally, an (8,4;5) RS code over GF (512) in the binary representation of the (72,36;15) box code gives rise to a (72,36;16*) code with nine words of weight eight, and all the rest have weights greater than or equal to 16.

  15. Dopamine D2 receptor SPECT imaging

    International Nuclear Information System (INIS)

    The purposes of this study were to evaluate the utility of kit formulation, the basic in vivo charactristics, and clinical usefulness of dopamine D2 receptor imaging with 123I-(S)-(-)-3-iodo-2-hydroxy-6-methoxy-N-[(1-ethyl-2-pyrrodinyl)methyl]-benzamide (123I-IBZM). We studied 22 normal controls, 3 early symptomatic Huntington's disease patients, and 1 patient with visual hallucination on and off neuroleptics. 123I-IBZM could be conveniently prepared with a high degree of purity from a kit, but with relatively low radiochemical yield. We demonstrated 123I-IBZM receptor binding equilibrium by performing serial SPECT scanning in a normal volunteer. The basal ganglia/frontal cortex (BG/FC) ratios plateaued after the specific binding reached equilibrium approximately 60 minutes after injection. The BG/FC ratio declined significantly with age. The ratios for the Huntington's disease patients were significantly lower than those for normal controls. The images of the patient off neuroleptic therapy showed dramatically increased BG activity compared with those obtained while on therapy. The BG/FC ratio provides an estimate of Bmax/Kd and hence the receptor density. It appears important to perform SPECT early in the equilibrium phase and at a fixed time after injection to obtain significantly high signal to noise ratios. 123I-IBZM is an ideal tracer for SPECT including a rotating gamma camera type which can provide estimates of the receptor density objectively by calculating the BG/FC ratio, and is a promising agent for the investigation of dopamine D2 receptors in clinical conditions. (author)

  16. Keller-box method and its application

    CERN Document Server

    Prasad, Kerehalli V

    2014-01-01

    Most of the problems arising in science and engineering are nonlinear. They are inherently difficult to solve. Traditional analytical approximations are valid only for weakly nonlinear problems, and often break down for problems with strong nonlinearity. This book presents the current theoretical developments and applications of Keller-Box method to nonlinear problems. The first half of the bookaddresses basic concepts to understand the theoretical framework for the method. In the second half of the book, the authorsgive a number of examples of coupled nonlinear problems that have been solved

  17. Mirror box therapy: seeing is believing.

    Science.gov (United States)

    Lamont, Kelly; Chin, May; Kogan, Mikhail

    2011-01-01

    Working with patients with different chronic pain syndromes can be challenging. Pharmacological therapies are often associated with variety of side effects. Mind-body modalities are thought to play a role; however, the lack of clear consensus and large body of clinical experience makes it hard to provide good evidence-based recommendation to most of our chronic pain patients. In recent years the Phantom Limb Pain (PLP) and to some degree Complex Regional Pain Syndrome (CRPS) may prove to be an exception. In this review we summarize the current evidence supporting use of Mirror Box Therapy and its successor, Immersive Virtual Reality. PMID:22051561

  18. The Transformation of the "Black Box"

    OpenAIRE

    JIMENEZ DOMENECH, LUCIA

    2012-01-01

    The idea of this project is to convert an old office building downtown into an energy-neutral high-rise village. The assignment contained the office building located in the city centre of Groningen at Eendrachtskade 2, commonly called the "Black Box". It was built in 1976, and the actual technical condition is poor with inadequate insulation. When the building remains empty in 2014, the most obvious next thing to happen is the demolition. But, due to climate impact, the objective is to reuse ...

  19. Test procedure for boxed waste assay system

    International Nuclear Information System (INIS)

    This document, prepared by Los Alamos National Laboratory's NMT-4 group, details the test methodology and requirements for Acceptance/Qualification testing of a Boxed Waste Assay System (BWAS) designed and constructed by Pajarito Scientific Corporation. Testing of the BWAS at the Plutonium Facility (TA55) at Los Alamos National Laboratory will be performed to ascertain system adherence to procurement specification requirements. The test program shall include demonstration of conveyor handling capabilities, gamma ray energy analysis, and imaging passive/active neutron accuracy and sensitivity. Integral to these functions is the system's embedded operating and data reduction software

  20. Box model for channels of human migration

    CERN Document Server

    Vitanov, Nikolay K

    2016-01-01

    We discuss a mathematical model of migration channel based on the truncated Waring distribution. The truncated Waring distribution is obtained for a more general model of motion of substance through a channel containing finite number of boxes. The model is applied then for case of migrants moving through a channel consisting of finite number of countries or cities. The number of migrants in the channel strongly depends on the number of migrants that enter the channel through the country of entrance. It is shown that if the final destination country is very popular then large percentage of migrants may concentrate there.

  1. Radiometry of radiochemical processing plant box

    International Nuclear Information System (INIS)

    Radiometry method is used to detect shielding losses in the newly designed processing plants, to control the personnel exposure handling the radioactivity. The acceptable radiation level in occupied area at the working place, as per AERB regulatory guidelines is 1 μSv/h (0.1mR/h). Hence a stringent control on the shielding is mandatory. The shielding integrity was evaluated using a sealed source of 900 mCi 60Co (1.17 MeV and 1.33 MeV g photons of 100% abundance), by radiometry at -the newly designed 100 mm lead shielded SS 6 cell -plant box used for processing 5 -10Ci of 32P, 51Cr,153Sm, 177Lu, 166Ho etc. The radiometry source introduced into plant box through the loading chamber in H2 can (Dia. 25 mm and length 40 mm) was loaded in the plant. MS stand was fabricated and used for housing the radiometry source at different elevations (300, 600 and 900 mm). The stand was kept in the center of the plant at different locations viz., 845 mm, 1445 mm and 2045 mm distance from one side. The transmitted radiation field was mapped using radiation survey meter at marked grid segments of 100 mm x 100 mm in all sides and top of the plant box. The transmitted radiation field in all sides and top of the plant box were mapped using radiation survey meter. At certain grids the radiation levels indicated shielding losses, all such cavities were filled up, the gap was plugged and the radiometry dose mapping was repeated. Due to this rectification, radiation level at most of the places was reduced and the results showed that the shielding had improved. There was higher transmitted radiation field on the plant during opening of sliding doors. Whenever doors are opened during some work, alarm of audio alarm system indicates door opening condition. Installation of the same had been made mandatory to control occupational exposure. The radiation level may not exceed the limit of 1 μ iSv/h for the permanent occupancy of lab personnel at the working place

  2. Smart Distribution Boxes, Complete Energy Management

    Energy Technology Data Exchange (ETDEWEB)

    Platise, Uros

    2010-09-15

    Present households demand side management implementations are turning conventional appliances into smart ones to support auto demand (AutoDR) response function. Present concept features a direct link between the power meters and appliances. In this paper new concept and example of implementation of a so-called Smart Distribution Box (SmartDB) is represented for complete energy and power management. SmartDBs, as an intermediate layer, are extending smart grid power meter functionality to support AutoDR with fast and guaranteed response times, distributed power sources, and besides provide full control over energy management and extra safety functions to the consumers.

  3. LHC Crab Cavity Coupler Test Boxes

    CERN Document Server

    Mitchell, James; Burt, Graeme; Calaga, Rama; Macpherson, Alick; Montesinos, Eric; Silva, Subashini; Tutte, Adam; Xiao, Binping

    2016-01-01

    The LHC double quarter wave (DQW) crab cavities have two different types of Higher Order Mode (HOM) couplers in addition to a fundamental power coupler (FPC). The FPC requires conditioning, so to achieve this we have designed a radio-frequency (RF) quarter wave resonator to provide high transmission between two opposing FPCs. For the HOM couplers we must ensure that the stop-band filter is positioned at the cavity frequency and that peak transmission occurs at the same frequencies as the strongest HOMs. We have designed two test boxes which preserve the cavity spectral response in order to test the couplers.

  4. Slepton pair production in the POWHEG BOX

    International Nuclear Information System (INIS)

    We present an implementation for slepton pair production at hadron colliders in the POWHEG BOX, a framework for combining next-to-leading order QCD calculations with parton-shower Monte-Carlo programs. Our code provides a SUSY Les Houches Accord interface for setting the supersymmetric input parameters. Decays of the sleptons and parton-shower effects are simulated with PYTHIA. Our Monte-Carlo program allows the generation of events, and thus of arbitrary distributions with appropriate selection cuts. Kinematic distributions of experimentally observable quantities are shown for a representative point in the supersymmetric parameter space.

  5. Seismic stability of a standalone glove box structure

    International Nuclear Information System (INIS)

    Highlights: • Glove box is a leak tight, safety related structure used for handling radiotoxic materials. • To study the seismic performance of a freestanding glove box, extensive shake table testing has been carried out. • Glove box maintained structural integrity and leak tightness up to design basis earthquake loading. • Detailed three-dimensional finite element model of the structure is developed and analyzed by using direct time integration methods. • Simplified numerical method is proposed and successfully applied, to quickly estimate sliding displacement and determine upper bounds for it. - Abstract: In a nuclear fuel cycle facility, radiotoxic materials are being handled in freestanding leak tight enclosures called glove boxes (GBs). These glove boxes act as a primary confinement for the radiotoxic materials. Glove boxes are designed as per codal requirements for class I component. They are designed to withstand extreme level of earthquake loading with a return period of 10,000 years. To evaluate seismic performance of the glove box, there is a need to check the stability (sliding and overturning), structural integrity (stresses and strains) and leak tightness under earthquake loading. Extensive shake table experiments were conducted on a single standalone glove box. Actual laboratory conditions were simulated during testing to check the response. After extensive shake table testing, glove box structure was also analyzed using finite element (FE) software. Detailed three-dimensional model of glove box structure was developed and analyzed using nonlinear time history method. It was observed that finite element methods could be utilized to accurately predict dynamic response of glove box structure. This paper discusses the details and results of shake table testing and methodology used for modelling and analysing freestanding glove box structure under seismic loading. In addition, simplified numerical procedure, developed using energy conservation

  6. Seismic stability of a standalone glove box structure

    Energy Technology Data Exchange (ETDEWEB)

    Saraswat, A., E-mail: anupams@barc.gov.in [Bhabha Atomic Research Centre, Mumbai (India); Reddy, G.R. [Bhabha Atomic Research Centre, Mumbai (India); Ghosh, S. [Indian Institute of Technology Bombay, Mumbai (India); Ghosh, A.K.; Kumar, Arun [Bhabha Atomic Research Centre, Mumbai (India)

    2014-09-15

    Highlights: • Glove box is a leak tight, safety related structure used for handling radiotoxic materials. • To study the seismic performance of a freestanding glove box, extensive shake table testing has been carried out. • Glove box maintained structural integrity and leak tightness up to design basis earthquake loading. • Detailed three-dimensional finite element model of the structure is developed and analyzed by using direct time integration methods. • Simplified numerical method is proposed and successfully applied, to quickly estimate sliding displacement and determine upper bounds for it. - Abstract: In a nuclear fuel cycle facility, radiotoxic materials are being handled in freestanding leak tight enclosures called glove boxes (GBs). These glove boxes act as a primary confinement for the radiotoxic materials. Glove boxes are designed as per codal requirements for class I component. They are designed to withstand extreme level of earthquake loading with a return period of 10,000 years. To evaluate seismic performance of the glove box, there is a need to check the stability (sliding and overturning), structural integrity (stresses and strains) and leak tightness under earthquake loading. Extensive shake table experiments were conducted on a single standalone glove box. Actual laboratory conditions were simulated during testing to check the response. After extensive shake table testing, glove box structure was also analyzed using finite element (FE) software. Detailed three-dimensional model of glove box structure was developed and analyzed using nonlinear time history method. It was observed that finite element methods could be utilized to accurately predict dynamic response of glove box structure. This paper discusses the details and results of shake table testing and methodology used for modelling and analysing freestanding glove box structure under seismic loading. In addition, simplified numerical procedure, developed using energy conservation

  7. Effects of Dopamine D2 Receptor Partial Agonist Antipsychotic Aripiprazole on Dopamine Synthesis in Human Brain Measured by PET with L-[β-11C]DOPA

    OpenAIRE

    Ito, Hiroshi; Takano, Harumasa; Arakawa, Ryosuke; Takahashi, Hidehiko; Kodaka, Fumitoshi; Takahata, Keisuke; Nogami, Tsuyoshi; Suzuki, Masayuki; Suhara, Tetsuya

    2012-01-01

    Dopamine D2 receptor partial agonist antipsychotic drugs can modulate dopaminergic neurotransmission as functional agonists or functional antagonists. The effects of antipsychotics on presynaptic dopaminergic functions, such as dopamine synthesis capacity, might also be related to their therapeutic efficacy. Positron emission tomography (PET) was used to examine the effects of the partial agonist antipsychotic drug aripiprazole on presynaptic dopamine synthesis in relation to dopamine D2 rece...

  8. An inverse correlation between apparent rate of dopamine clearance and tonic autoinhibition in subdomains of the rat striatum: a possible role of transporter-mediated dopamine efflux

    OpenAIRE

    Moquin, Keith F.; Michael, Adrian C.

    2011-01-01

    The dopaminergic terminal field in the rat striatum is compartmentalized into subdomains that exhibit distinct dynamics of electrically evoked dopamine release. The fast striatal domains, where dopamine release is predominantly vesicular, exhibit conventional dopaminergic activity. However, vesicular dopamine release is tonically autoinhibited in the slow domains, which suggests that dopamine reaches the autoreceptors via a non-vesicular route. Hence, it appears that the domains use distinct ...

  9. Striatal dopamine release codes uncertainty in pathological gambling

    DEFF Research Database (Denmark)

    Linnet, Jakob; Mouridsen, Kim; Peterson, Ericka;

    2012-01-01

    Two mechanisms of midbrain and striatal dopaminergic projections may be involved in pathological gambling: hypersensitivity to reward and sustained activation toward uncertainty. The midbrain—striatal dopamine system distinctly codes reward and uncertainty, where dopaminergic activation is a linear...

  10. Striatal dopamine release codes uncertainty in pathological gambling

    DEFF Research Database (Denmark)

    Linnet, Jakob; Mouridsen, Kim; Peterson, Ericka;

    2012-01-01

    Two mechanisms of midbrain and striatal dopaminergic projections may be involved in pathological gambling: hypersensitivity to reward and sustained activation toward uncertainty. The midbrain-striatal dopamine system distinctly codes reward and uncertainty, where dopaminergic activation is a linear...

  11. Teaching Outside the Box: ARL Librarians' Integration of the "One- Box" into Student Instruction

    Science.gov (United States)

    Kulp, Christina; McCain, Cheryl; Scrivener, Laurie

    2014-01-01

    This article reports the results of a survey that targeted reference and instruction librarians who work at libraries that are members of the Asso- ciation of Research Libraries (ARL). Respondents were asked to indicate whether or not they teach students to use the one-box tool, and why or why not. Based on the responses of the 352 librarians who…

  12. Dopamine and glucose, obesity and Reward Deficiency Syndrome

    Directory of Open Access Journals (Sweden)

    Kenneth eBlum

    2014-09-01

    Full Text Available Obesity and many well described eating disorders are accurately considered a global epidemic. The consequences of Reward Deficiency Syndrome, a genetic and epigenetic phenomena that involves the interactions of powerful neurotransmitters, are impairments of brain reward circuitry, hypodopaminergic function and abnormal craving behavior. Numerous sound neurochemical and genetic studies provide strong evidence that food addiction is similar to psychoactive drug addiction. Important facts which could translate to potential therapeutic targets espoused in this review include: 1 brain dopamine (DA production and use is stimulated by consumption of alcohol in large quantities or carbohydrates bingeing; 2 in the mesolimbic system the enkephalinergic neurons are in close proximity, to glucose receptors; 3 highly concentrated glucose activates the calcium channel to stimulate dopamine release from P12 cells; 4 blood glucose and cerebrospinal fluid concentrations of homovanillic acid, the dopamine metabolite, are significantly correlated and 5 2-deoxyglucose the glucose analogue, in pharmacological doses associates with enhanced dopamine turnover and causes acute glucoprivation. Evidence from animal studies and human fMRI support the hypothesis that multiple, but similar brain circuits are disrupted in obesity and drug dependence and DA-modulated reward circuits are involved in pathologic eating behaviors. Treatment for addiction to glucose and drugs alike, based on a consensus of neuroscience research, should incorporate dopamine agonist therapy, in contrast to current theories and practices that use dopamine antagonists. Until now, powerful dopamine-D2 agonists have failed clinically, due to chronic down regulation of D2 receptors instead, consideration of novel less powerful D2 agonists that up-regulate D2 receptors seems prudent. We encourage new strategies targeted at improving DA function in the treatment and prevention of obesity a subtype of

  13. Dopamine-beta hydroxylase polymorphism and cocaine addiction

    OpenAIRE

    Collier David; Laranjeira Ronaldo; Guindalini Camila; Messas Guilherme; Vallada Homero; Breen Gerome

    2008-01-01

    Abstract Cocaine addiction involves a number of medical, psychological and social problems. Understanding the genetic aetiology of this disorder will be essential for design of effective treatments. Dopamine-beta hydroxylase (DbH) catalyzes the conversion of dopamine to norepinephrine and could, therefore, have an influence on both cocaine action and the basal sensitivity of neurotransmitter systems to cocaine. Recently, the -1021C>T polymorphism have been found to strongly correlated with in...

  14. Amphetamine Self-Administration Attenuates Dopamine D2 Autoreceptor Function

    OpenAIRE

    Calipari, Erin S.; Sun, Haiguo; Eldeeb, Khalil; Luessen, Deborah J; Feng, Xin; Howlett, Allyn C.; JONES, SARA R.; Chen, Rong

    2014-01-01

    Dopamine D2 autoreceptors located on the midbrain dopaminergic neurons modulate dopamine (DA) neuron firing, DA release, and DA synthesis through a negative-feedback mechanism. Dysfunctional D2 autoreceptors following repeated drug exposure could lead to aberrant DA activity in the ventral tegmental area (VTA) and projection areas such as nucleus accumbens (NAcc), promoting drug-seeking and -taking behavior. Therefore, it is important to understand molecular mechanisms underlying drug-induced...

  15. The dopamine withdrawal test following surgery for intracranial aneurysms.

    OpenAIRE

    Mendelow, A D; Dharker, S; J. Patterson; Nath, F; Teasdale, G M

    1986-01-01

    Cerebral blood flow was measured in eight patients who were being treated with dopamine in order to maintain cerebral perfusion after the onset of delayed postoperative ischaemia following intracranial aneurysm surgery. Measurements were made whilst on treatment and repeated either during a reduction in the dosage or withdrawal of dopamine. There was a significant fall in cerebral blood flow in both hemispheres in all eight patients. Clinical deterioration was observed in seven of nine instan...

  16. Dopamine receptor expression and function in corticotroph pituitary tumors

    OpenAIRE

    Pivonello, Rosario; Lamberts, Steven; Ferone, Diego; De Herder, Wouter; Kros, Johan; Caro, M.L.; M. Arvigo; Annunziato, L; Lombardi, Gaetano; Colao, Annamaria; Hofland, Leo

    2004-01-01

    textabstractThe role of dopamine agonist treatment in corticotroph pituitary tumors is controversial. The aim of this study was to evaluate D(2) receptor expression in 20 corticotroph pituitary tumors and to correlate it to the in vitro effect of dopamine agonists on ACTH secretion and the in vivo effect of short-term cabergoline treatment on cortisol secretion. D(2) expression was evaluated by receptor-ligand binding, immunohistochemistry, and RT-PCR. A 50% or more decrease in daily urinary ...

  17. Pharmacologic Neuroimaging of the Ontogeny of Dopamine Receptor Function

    OpenAIRE

    Chen, Y. Iris; Choi, Ji-Kyung; Xu, Haibo; Ren, Jiaqian; Andersen, Susan L.; Jenkins, Bruce G.

    2010-01-01

    Characterization of the ontogeny of the cerebral dopaminergic system is crucial for gaining a greater understanding of normal brain development and its alterations in response to drugs of abuse or conditions such as attention-deficit hyperactivity disorder. Pharmacological MRI (phMRI) was used to determine the response to dopamine transporter (DAT) blockers cocaine and methylphenidate (MPH), the dopamine releaser D-amphetamine (AMPH), the selective D1 agonist dihydrexidine, and the D2/D3 agon...

  18. Developmental changes in human dopamine neurotransmission: cortical receptors and terminators

    Directory of Open Access Journals (Sweden)

    Rothmond Debora A

    2012-02-01

    Full Text Available Abstract Background Dopamine is integral to cognition, learning and memory, and dysfunctions of the frontal cortical dopamine system have been implicated in several developmental neuropsychiatric disorders. The dorsolateral prefrontal cortex (DLPFC is critical for working memory which does not fully mature until the third decade of life. Few studies have reported on the normal development of the dopamine system in human DLPFC during postnatal life. We assessed pre- and postsynaptic components of the dopamine system including tyrosine hydroxylase, the dopamine receptors (D1, D2 short and D2 long isoforms, D4, D5, catechol-O-methyltransferase, and monoamine oxidase (A and B in the developing human DLPFC (6 weeks -50 years. Results Gene expression was first analysed by microarray and then by quantitative real-time PCR. Protein expression was analysed by western blot. Protein levels for tyrosine hydroxylase peaked during the first year of life (p O-methyltransferase (p = 0.024 were significantly higher in neonates and infants as was catechol-O-methyltransferase protein (32 kDa, p = 0.027. In contrast, dopamine D1 receptor mRNA correlated positively with age (p = 0.002 and dopamine D1 receptor protein expression increased throughout development (p Conclusions We find distinct developmental changes in key components of the dopamine system in DLPFC over postnatal life. Those genes that are highly expressed during the first year of postnatal life may influence and orchestrate the early development of cortical neural circuitry while genes portraying a pattern of increasing expression with age may indicate a role in DLPFC maturation and attainment of adult levels of cognitive function.

  19. Dopamine release in ventral striatum of pathological gamblers losing money

    DEFF Research Database (Denmark)

    Linnet, J; Peterson, E; Doudet, D J; Gjedde, A; Møller, A

    2010-01-01

    Linnet J, Peterson E, Doudet DJ, Gjedde A, Møller A. Dopamine release in ventral striatum of pathological gamblers losing money. Objective: To investigate dopaminergic neurotransmission in relation to monetary reward and punishment in pathological gambling. Pathological gamblers (PG) often continue...... suggest a dopaminergic basis of monetary losses in pathological gambling, which might explain loss-chasing behavior. The findings may have implications for the understanding of dopamine dysfunctions and impaired decision-making in pathological gambling and substance-related addictions....

  20. Epigenetic Effect of Chronic Stress on Dopamine Signaling and Depression

    OpenAIRE

    Sofia Moriam; Mahbub E. Sobhani

    2013-01-01

    Because of the complex causal factors leading to depression, epigenetics is of considerable interest for the understanding effect of stress in depression. Dopamine is a key neurotransmitter important in many physiological functions, including motor control, mood, and the reward pathway. These factors lead many drugs to target Dopamine receptors in treating depressive disorders. In this review, we try to portray how chronic stress as an epigenetic factor changes the gene regulation pattern by ...

  1. IA-2 modulates dopamine secretion in PC12 cells

    OpenAIRE

    Nishimura, Takuya; Harashima, Shin-ichi; Yafang, Hu; Notkins, Abner Louis

    2009-01-01

    The secretion of the hormone insulin from beta cells is modulated by the expression of the dense core vesicle transmembrane protein IA-2. Since IA-2 is found in neuroendocrine cells throughout the body, the present experiments were initiated to determine whether the expression of IA-2 also modulates the secretion of neurotransmitters. Using the dopamine-secreting pheochromocytoma cell line PC12, we found that the overexpressions of IA-2 increased the cellular content and secretion of dopamine...

  2. Alterations in blood glucose levels under hyperinsulinemia affect accumbens dopamine

    OpenAIRE

    Bello, Nicholas T.; Hajnal, Andras

    2006-01-01

    Dopaminergic systems have been implicated in diabetes and obesity. Notwithstanding, the most basic relationship between dopamine and plasma insulin as well as glucose levels yet remains unknown. The present experiments were designed to investigate the effects of acute hyperinsulinemia on basal dopamine levels in the nucleus accumbens of the rat under chloral hydrate anesthesia using acute microdialysis in combination with the hyperinsulinemic-glycemic clamping procedure. In Experiment 1, each...

  3. An Overview of the Association between Schizotypy and Dopamine

    OpenAIRE

    Christine eMohr; Ulrich eEttinger

    2014-01-01

    Schizotypy refers to a constellation of personality traits that are believed to mirror the subclinical expression of schizophrenia in the general population. Evidence from pharmacological studies indicates that dopamine is involved in the aetiology of schizophrenia. Based on the assumption of a continuum between schizophrenia and schizotypy, researchers have begun investigating the association between dopamine and schizotypy using a wide range of methods. In this article, we review published ...

  4. Could Dopamine Agonists Aid in Drug Development for Anorexia Nervosa?

    Directory of Open Access Journals (Sweden)

    Guido eFrank

    2014-11-01

    Full Text Available Anorexia nervosa is a severe psychiatric disorder most commonly starting during the teenage years and associated with food refusal and low body weight. Typically there is a loss of menses, intense fear of gaining weight and an often delusional quality of altered body perception. Anorexia nervosa is also associated with a pattern of high cognitive rigidity, which may contribute to treatment resistance and relapse. The complex interplay of state and trait biological, psychological and social factors has complicated identifying neurobiological mechanisms that contribute to the illness. The dopamine D1 and D2 neurotransmitter receptors are involved in motivational aspects of food approach, fear extinction and cognitive flexibility. They could therefore be important targets to improve core and associated behaviors in anorexia nervosa. Treatment with dopamine antagonists has shown little benefit, and it is possible that antagonists over time increase an already hypersensitive dopamine pathway activity in anorexia nervosa. On the contrary, application of dopamine receptor agonists could reduce circuit responsiveness, facilitate fear extinction and improve cognitive flexibility in anorexia nervosa, as they may be particularly effective during underweight and low gonadal hormone states. This article provides evidence that the dopamine receptor system could be a key factor in the pathophysiology of anorexia nervosa and dopamine agonists could be helpful in reducing core symptoms of the disorder. This review is a theoretical approach that primarily focuses on dopamine receptor function as this system has been mechanistically better described than other neurotransmitters that are altered in anorexia nervosa. However, those proposed dopamine mechanisms in anorexia nervosa also warrant further study with respect to their interaction with other neurotransmitter systems, such as serotonin pathways.

  5. Selective modulation of excitatory and inhibitory microcircuits by dopamine

    OpenAIRE

    Gao, Wen-Jun; Goldman-Rakic, Patricia S.

    2003-01-01

    Dopamine plays an important role in the working memory functions of the prefrontal cortex, functions that are impacted in age-related memory decline, drug abuse, and a wide variety of disorders, including schizophrenia and Parkinson's disease. We have previously reported that dopamine depresses excitatory transmission between pyramidal neurons in the prefrontal cortex. Here, using paired recordings, we have investigated dopaminergic modulation of excitatory transmission from pyramidal neurons...

  6. Dopamine and Impulse Control Disorders in Parkinson’s Disease

    OpenAIRE

    Weintraub, Daniel

    2008-01-01

    There is an increasing awareness that impulse control disorders (ICDs), including compulsive gambling, buying, sexual behavior, and eating, can occur as a complication of Parkinson’s disease (PD). In addition, other impulsive or compulsive disorders have been reported to occur, including dopamine dysregulation syndrome (DDS) and punding. Case reporting and prospective studies have reported an association between ICDs and the use of dopamine agonists (DAs), particularly at greater dosages, whe...

  7. Dorsal Striatal Dopamine, Food Preference and Health Perception in Humans

    OpenAIRE

    2014-01-01

    To date, few studies have explored the neurochemical mechanisms supporting individual differences in food preference in humans. Here we investigate how dorsal striatal dopamine, as measured by the positron emission tomography (PET) tracer [18F]fluorometatyrosine (FMT), correlates with food-related decision-making, as well as body mass index (BMI) in 16 healthy-weight to moderately obese individuals. We find that lower PET FMT dopamine synthesis binding potential correlates with higher BMI, gr...

  8. Dorsal striatal dopamine, food preference and health perception in humans

    OpenAIRE

    Wallace, D L; Aarts, E.; Dang, L.C.; Greer, S.M.; Jagust, W.J.; D'Esposito, M.

    2014-01-01

    To date, few studies have explored the neurochemical mechanisms supporting individual differences in food preference in humans. Here we investigate how dorsal striatal dopamine, as measured by the positron emission tomography (PET) tracer [(18)F]fluorometatyrosine (FMT), correlates with food-related decision-making, as well as body mass index (BMI) in 16 healthy-weight to moderately obese individuals. We find that lower PET FMT dopamine synthesis binding potential correlates with higher BMI, ...

  9. BASAL GANGLIA PATHOLOGY IN SCHIZOPHRENIA: DOPAMINE CONNECTIONS and ANOMALIES

    OpenAIRE

    Perez-Costas, Emma; Melendez-Ferro, Miguel; Roberts, Rosalinda C.

    2010-01-01

    Schizophrenia is a severe mental illness that affects 1% of the world population. The disease usually manifests itself in early adulthood with hallucinations, delusions, cognitive and emotional disturbances and disorganized thought and behavior. Dopamine was the first neurotransmitter to be implicated in the disease, and though no longer the only suspect in schizophrenia pathophysiology, it obviously plays an important role. The basal ganglia are the site of most of the dopamine neurons in th...

  10. Could dopamine agonists aid in drug development for anorexia nervosa?

    Science.gov (United States)

    Frank, Guido K W

    2014-01-01

    Anorexia nervosa is a severe psychiatric disorder most commonly starting during the teenage-years and associated with food refusal and low body weight. Typically there is a loss of menses, intense fear of gaining weight, and an often delusional quality of altered body perception. Anorexia nervosa is also associated with a pattern of high cognitive rigidity, which may contribute to treatment resistance and relapse. The complex interplay of state and trait biological, psychological, and social factors has complicated identifying neurobiological mechanisms that contribute to the illness. The dopamine D1 and D2 neurotransmitter receptors are involved in motivational aspects of food approach, fear extinction, and cognitive flexibility. They could therefore be important targets to improve core and associated behaviors in anorexia nervosa. Treatment with dopamine antagonists has shown little benefit, and it is possible that antagonists over time increase an already hypersensitive dopamine pathway activity in anorexia nervosa. On the contrary, application of dopamine receptor agonists could reduce circuit responsiveness, facilitate fear extinction, and improve cognitive flexibility in anorexia nervosa, as they may be particularly effective during underweight and low gonadal hormone states. This article provides evidence that the dopamine receptor system could be a key factor in the pathophysiology of anorexia nervosa and dopamine agonists could be helpful in reducing core symptoms of the disorder. This review is a theoretical approach that primarily focuses on dopamine receptor function as this system has been mechanistically better described than other neurotransmitters that are altered in anorexia nervosa. However, those proposed dopamine mechanisms in anorexia nervosa also warrant further study with respect to their interaction with other neurotransmitter systems, such as serotonin pathways. PMID:25988121

  11. Hairy Black Holes in a Box

    CERN Document Server

    Basu, Pallab; Subramanian, P N Bala

    2016-01-01

    We do a systematic study of the phases of gravity coupled to an electromagnetic field and charged scalar in flat space, with box boundary conditions. The scalar-less box has previously been investigated by Braden, Brown, Whiting and York (and others) before AdS/CFT and we elaborate and extend their results in a language more familiar from holography. The phase diagram of the system is analogous to that of AdS black holes, but we emphasize the differences and explain their origin. Once the scalar is added, we show that the system admits both boson stars as well as hairy black holes as solutions, providing yet another way to evade flat space no-hair theorems. Furthermore both these solutions can exist as stable phases in regions of the phase diagram. The final picture of the phases that emerges is strikingly similar to that found recently for holographic superconductors in global AdS, arXiv: 1602.07211. Our construction lays bare certain previously unnoticed subtleties associated to the definition quasi-local c...

  12. Expression of N-methyl-D-aspartic acid 2A-B and 2B receptors in anterior thalamic nucleus and subiculum complex of rats

    Institute of Scientific and Technical Information of China (English)

    Yuanshan Fu; Xiaokai Ma; Xiaoling Yue; Bin Wang

    2008-01-01

    BACKGROUND: Glutamate acid ionotropic receptor N-methyl-D-aspartic acid (NMDA) takes part in long-term potentiation, thereby influencing the process of learning and memory.OBJECTIVE: To verify expression of NMDA 2A/B and 2B receptors in the anterior thalamic nucleus and subieulum complex of rats.DESIGN, TIME AND SETTING: A single-sample observation was performed at Department of Anatomy in Dalian Mcdical University (Dalian, Liaoning, China) from April to September in 2007.MATERIALS: Ten adult Wistar rats were used for this study, as well as rabbit anti-NMDA 2A/B and 2Bantibodies.METHODS: The rats were anesthetized and perfused, followed by brain resection and coronal sectioning of the brain tissue. A 1:3 series was selected for immunohistochemistry, using antibodies specific to NMDA 2A/B and 2B receptors. Photos were taken using the Nikon image analysis system.MAIN OUTCOME MEASURES: Expression and distribution of immunohistochemistry staining of NMDA 2A/B and 2B receptor subunits.RESULTS: There were a large number of NMDA 2A/B and 2B receptor-positive neurons distributed throughout the anterior dorsal thalamic nucleus. In the anterior ventral thalamic nucleus, distribution of positive neurons was rare, staining intensity was lighter, and cell bodies were smaller compared with the anterior dorsal thalamic nucleus. In the subiculum complex, staining intensity of NMDA 2A/B and 2B-positive neurons was weakest in the molecular layer and stronger in the pyramidal layer, in particular the region with large cell bodies adjacent to the molecular layer. In the multiform layer, more positive neurons of various sizes were detected.CONCLUSION: NMDA 2A/B and 2B receptor subunits were richly distributed in the anterior thalamic nucleus, with a small difference existing between the anterior dorsal nucleus and anterior ventral nucleus.These neurons were also differentially distributed within the three layers of the subiculum complex.

  13. Roles of F-box Proteins in Plant Hormone Responses

    Institute of Scientific and Technical Information of China (English)

    Haichuan YU; Jiao WU; Nanfei XU; Ming PENG

    2007-01-01

    The F-box protein is an important component of the E3 ubiquitin ligase Skpl-Cullin-F-box protein complex. It binds specific substrates for ubiquitin-mediated proteolysis. The F-box proteins contain a signature F-box motif at their amino-terminus and some protein-protein interaction motifs at their carboxyterminus, such as Trp-Asp repeats or leucine rich repeats. Many F-box proteins have been identified to be involved in plant hormone response as receptors or important medial components. These breakthrough findings shed light on our current understanding of the structure and function of the various F-box proteins,their related plant hormone signaling pathways, and their roles in regulating plant development.

  14. Software sensors based on the grey-box modelling approach

    DEFF Research Database (Denmark)

    Carstensen, J.; Harremoës, P.; Strube, Rune

    1996-01-01

    In recent years the grey-box modelling approach has been applied to wastewater transportation and treatment Grey-box models are characterized by the combination of deterministic and stochastic terms to form a model where all the parameters are statistically identifiable from the on......-box model for the specific dynamics is identified. Similarly, an on-line software sensor for detecting the occurrence of backwater phenomena can be developed by comparing the dynamics of a flow measurement with a nearby level measurement. For treatment plants it is found that grey-box models applied to on......-line measurements. With respect to the development of software sensors, the grey-box models possess two important features. Firstly, the on-line measurements can be filtered according to the grey-box model in order to remove noise deriving from the measuring equipment and controlling devices. Secondly, the grey...

  15. Antibacterial surfaces through dopamine functionalization and silver nanoparticle immobilization

    International Nuclear Information System (INIS)

    Immobilization of silver nanoparticles on the dopamine functionalized polyimide (PI) films was carried out by photo-induced silver ion-reduction under atmosphere conditions. The dopamine has been successfully deposited on the PI surface in mild aqueous environments. The effects of pH, dopamine concentration and reaction time on the dopamine polymerization were investigated. The water contact angles of the poly(dopamine) functionalized PI films reduced remarkably in comparison with that of the pristine PI film. The chemical composition and structure of the UV-induced deposited-silver on the modified PI films were characterized by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The topography of the modified PI films was investigated by scanning electron microscope (SEM). The deposited poly(dopamine) layer acted as binding sites for the silver ions. The silver-plated PI films showed good antibacterial activity due to that biofilm formation was inhibited on the polymeric surfaces in contact with bacteria.

  16. An Overview of the Association between Schizotypy and Dopamine

    Directory of Open Access Journals (Sweden)

    Christine eMohr

    2014-12-01

    Full Text Available Schizotypy refers to a constellation of personality traits that are believed to mirror the subclinical expression of schizophrenia in the general population. Evidence from pharmacological studies indicates that dopamine is involved in the aetiology of schizophrenia. Based on the assumption of a continuum between schizophrenia and schizotypy, researchers have begun investigating the association between dopamine and schizotypy using a wide range of methods. In this article, we review published studies on this association from the following areas of work: (1 Experimental investigations of the interactive effects of dopaminergic challenges and schizotypy on cognition, motor control and behaviour, (2 dopaminergically supported cognitive functions, (3 studies of associations between schizotypy and polymorphisms in genes involved in dopaminergic neurotransmission, and (4 molecular imaging studies of the association between schizotypy and markers of the dopamine system. Together, data from these lines of evidence suggest that dopamine is important to the expression and experience of schizotypy and associated behavioural biases. An important observation is that the experimental designs, methods, and manipulations used in this research are highly heterogeneous. Future studies are required to replicate individual observations, to enlighten the link between dopamine and different schizotypy dimensions (positive, negative, cognitive disorganisation, and to guide the search for solid dopamine-sensitive behavioural markers. Such studies are important in order to clarify inconsistencies between studies. More work is also needed to identify differences between dopaminergic alterations in schizotypy compared to the dysfunctions observed in schizophrenia.

  17. Renal dopamine receptors: mechanisms of action and developmental aspects.

    Science.gov (United States)

    Cheung, P Y; Barrington, K J

    1996-01-01

    Dopamine is important for renal perfusion, natriuresis, and the control of blood pressure. Modulation of the activities of adenylyl cyclase, phospholipase C and protein kinases is involved in the signal transduction pathway of dopamine. Peripheral dopamine receptors are classified as the DA1 and DA2 subtypes on the basis of synaptic localization and their pharmacological profiles. In the kidney, DA1 receptors are localized in the medial layer of the renal vasculature and along the nephron; DA2 receptors are found in the glomerulus and the nerves surrounding renal blood vessels. While DA1 receptor stimulation results in renal vasodilatation and natriuresis, DA2 receptors may play a synergistic role in the DA1 modulated natriuresis. There is increasing evidence that these effects of dopamine are attenuated in younger than in older animals. Future studies should be directed to identify the ontogenic differences in vascular and tubular dopamine receptors (density and affinity) and their coupling mechanisms, in order to evaluate the role of dopamine which is frequently used in the management of shock in newborns. PMID:8849583

  18. Photoaffinity ligand for dopamine D2 receptors: azidoclebopride

    Energy Technology Data Exchange (ETDEWEB)

    Niznik, H.B.; Guan, J.H.; Neumeyer, J.L.; Seeman, P.

    1985-02-01

    In order to label D2 dopamine receptors selectively and covalently by means of a photosensitive compound, azidoclebopride was synthesized directly from clebopride. The dissociation constant (KD) of clebopride for the D2 dopamine receptor (canine brain striatum) was 1.5 nM, while that for azidoclebopride was 21 nM. The affinities of both clebopride and azidoclebopride were markedly reduced in the absence of sodium chloride. In the presence of ultraviolet light, azidoclebopride inactivated D2 dopamine receptors irreversibly, as indicated by the inability of the receptors to bind (/sup 3/H)spiperone. Maximal photoinactivation of about 60% of the D2 dopamine receptors occurred at 1 microM azidoclebopride; 30% of the receptors were inactivated at 80 nM azidoclebopride (pseudo-IC50). Dopamine agonists selectively protected the D2 receptors from being inactivated by azidoclebopride, the order of potency being (-)-N-n-propylnorapomorphine greater than apomorphine greater than (+/-)-6,7-dihydroxy-2-aminotetralin greater than (+)-N-n-propylnorapomorphine greater than dopamine greater than noradrenaline greater than serotonin. Similarly, dopaminergic antagonists prevented the photoinactivation of D2 receptors by azidoclebopride with the following order of potency: spiperone greater than (+)-butaclamol greater than haloperidol greater than clebopride greater than (-)-sulpiride greater than (-)-butaclamol.

  19. Selective modulation of excitatory and inhibitory microcircuits by dopamine

    Science.gov (United States)

    Gao, Wen-Jun; Goldman-Rakic, Patricia S.

    2003-03-01

    Dopamine plays an important role in the working memory functions of the prefrontal cortex, functions that are impacted in age-related memory decline, drug abuse, and a wide variety of disorders, including schizophrenia and Parkinson's disease. We have previously reported that dopamine depresses excitatory transmission between pyramidal neurons in the prefrontal cortex. Here, using paired recordings, we have investigated dopaminergic modulation of excitatory transmission from pyramidal neurons to fast-spiking (FS) interneurons. In contrast to its effect on recurrent excitation, dopamine was without effect on excitatory transmission to FS interneurons. However, dopamine has directly enhanced the excitability of the FS interneurons to the extent that even a single excitatory postsynaptic potential could initiate spiking with great temporal precision in some of them. These results indicate that dopamine's effects on excitatory transmission are target-specific and that the axon terminals of pyramidal neurons can be selectively regulated at the level of individual synapses. Thus, dopamine's net inhibitory effect on cortical function is remarkably constrained by the nature of the microcircuit elements on which it acts.

  20. Metaphit inhibits dopamine transport and binding of [3H]methylphenidate, a proposed marker for the dopamine transport complex

    International Nuclear Information System (INIS)

    Metaphit, an acylating derivative of phencyclidine, was shown to interact with components of the dopamine nerve terminal in rat striatal tissue. This compound, previously demonstrated to be an irreversible inhibitor at the phencyclidine receptor, was shown in these experiments to irreversibly inhibit synaptosomal [3H]dopamine uptake. It also inhibited binding of [3H]methylphenidate to its recognition site, which is thought to be a subunit of the dopamine transporter. Although the inhibition was due primarily to a reduction in the binding and transport capacity of the systems studied, increases in the apparent KD of [3H]methylphenidate and the Km of [3H]dopamine were also observed. Differences in the behavior of Metaphit and phencylidine in these dopaminergic systems compared to their effects on the NMDA receptor-linked phencyclidine receptor suggest that Metaphit may be interacting with two distinct molecular sites in the rat striatum

  1. Metaphit inhibits dopamine transport and binding of ( sup 3 H)methylphenidate, a proposed marker for the dopamine transport complex

    Energy Technology Data Exchange (ETDEWEB)

    Schweri, M.M. (Mercer Univ. School of Medicine, Macon, GA (USA)); Jacobson, A.E.; Rice, K.C. (National Institutes of Health, Bethesda, MD (USA)); Lessor, R.A.

    1989-01-01

    Metaphit, an acylating derivative of phencyclidine, was shown to interact with components of the dopamine nerve terminal in rat striatal tissue. This compound, previously demonstrated to be an irreversible inhibitor at the phencyclidine receptor, was shown in these experiments to irreversibly inhibit synaptosomal ({sup 3}H)dopamine uptake. It also inhibited binding of ({sup 3}H)methylphenidate to its recognition site, which is thought to be a subunit of the dopamine transporter. Although the inhibition was due primarily to a reduction in the binding and transport capacity of the systems studied, increases in the apparent K{sub D} of ({sup 3}H)methylphenidate and the K{sub m} of ({sup 3}H)dopamine were also observed. Differences in the behavior of Metaphit and phencylidine in these dopaminergic systems compared to their effects on the NMDA receptor-linked phencyclidine receptor suggest that Metaphit may be interacting with two distinct molecular sites in the rat striatum.

  2. A novel turning behavior control method for rat-robot through the stimulation of ventral posteromedial thalamic nucleus.

    Science.gov (United States)

    Xu, Kedi; Zhang, Jiacheng; Zhou, Hong; Lee, Ji Chao Tristan; Zheng, Xiaoxiang

    2016-02-01

    The concept of a rat-robot was initially introduced in 2002, bringing to the field, a novel area of research using modern research into neuroscience and robotics. This paper brings to the table, a study into the method best used for navigation systems in a rat-robot. Current research is epitomized by the use of reward-based spatial navigation, combining the concept of an induced reward sensation as well as a 'virtual touch' sensation to control the movement of the rat-robot. However, such methods are plagued by limitations affecting the success rate as well as preparation procedures which may have varying effects on different rats, even under similar conditions. Hence, this paper studies the stimulation of two different portions of the brain to induce a turning motion within the rat, namely the Ventral Posteromedial (VPM) thalamic nucleus as well as the Barrel-Field (BF) cortex and demonstrates the preferential usage of VPM as the choice use of navigational control in a rat-robot. PMID:26546880

  3. System identification of the nonlinear dynamics in the thalamocortical circuit in response to patterned thalamic microstimulation in vivo

    Science.gov (United States)

    Millard, Daniel C.; Wang, Qi; Gollnick, Clare A.; Stanley, Garrett B.

    2013-12-01

    Objective. Nonlinear system identification approaches were used to develop a dynamical model of the network level response to patterns of microstimulation in vivo. Approach. The thalamocortical circuit of the rodent vibrissa pathway was the model system, with voltage sensitive dye imaging capturing the cortical response to patterns of stimulation delivered from a single electrode in the ventral posteromedial thalamus. The results of simple paired stimulus experiments formed the basis for the development of a phenomenological model explicitly containing nonlinear elements observed experimentally. The phenomenological model was fit using datasets obtained with impulse train inputs, Poisson-distributed in time and uniformly varying in amplitude. Main results. The phenomenological model explained 58% of the variance in the cortical response to out of sample patterns of thalamic microstimulation. Furthermore, while fit on trial-averaged data, the phenomenological model reproduced single trial response properties when simulated with noise added into the system during stimulus presentation. The simulations indicate that the single trial response properties were dependent on the relative sensitivity of the static nonlinearities in the two stages of the model, and ultimately suggest that electrical stimulation activates local circuitry through linear recruitment, but that this activity propagates in a highly nonlinear fashion to downstream targets. Significance. The development of nonlinear dynamical models of neural circuitry will guide information delivery for sensory prosthesis applications, and more generally reveal properties of population coding within neural circuits.

  4. Thalamic form of Creutzfeldt-Jakob disease or fatal insomnia? Report of a sporadic case with normal prion protein genotype.

    Science.gov (United States)

    Kawasaki, K; Wakabayashi, K; Kawakami, A; Higuchi, M; Kitamoto, T; Tsuji, S; Takahashi, H

    1997-03-01

    We describe a 68-year-old man with a 53-month history of progressive dementia and clinical features of a progressive supranuclear palsy-like syndrome and dysautonomia. In the late stage of his illness, the patient also developed generalized myoclonic seizures. There was no family history of similar disorders. Histological examination revealed neuronal loss and gliosis with spongiosis in the cerebral cortex. In addition, more severe neuronal loss and gliosis without spongiosis were observed in the thalamus, especially in the anterior ventral and mediodorsal nuclei, and the inferior olivary nucleus. There was also obvious loss of Purkinje cells. Immunohistochemically, no protease-resistant prion protein (PrPres)-positive structures were demonstrated. However, Western blotting revealed the presence of PrPres in the cerebral cortex. This patient had a wild type of PrP genotype. We initially considered this to be a case of the thalamic form of Creutzfeldt-Jakob disease (CJD) with a long duration. However, it is noteworthy that essentially similar pathology, albeit with less severe cerebral cortical changes, has also been reported in fatal familial insomnia, a newly identified phenotypically different prion disease with a mutation in the PrP gene. On the basis of clinicopathological features, we eventually felt that this patient was more likely to have been a sporadic case of fatal insomnia (FI) of long duration. The present case appears to draw further attention to the possible relationship between CJD and FI. PMID:9083566

  5. Estradiol attenuates spinal cord injury-induced pain by suppressing microglial activation in thalamic VPL nuclei of rats.

    Science.gov (United States)

    Saghaei, Elham; Abbaszadeh, Fatemeh; Naseri, Kobra; Ghorbanpoor, Samar; Afhami, Mina; Haeri, Ali; Rahimi, Farzaneh; Jorjani, Masoumeh

    2013-04-01

    In our previous study we showed that central pain syndrome (CPS) induced by electrolytic injury caused in the unilateral spinothalamic tract (STT) is a concomitant of glial alteration at the site of injury. Here, we investigated the activity of glial cells in thalamic ventral posterolateral nuclei (VPL) and their contribution to CPS. We also examined whether post-injury administration of a pharmacological dose of estradiol can attenuate CPS and associated molecular changes. Based on the results,in the ipsilateral VPL the microglial phenotype switched o hyperactive mode and Iba1 expression was increased significantly on days 21 and 28 post-injury. The same feature was observed in contralateral VPL on day 28 (P<.05). These changes were strongly correlated with the onset of CPS (r(2)=0.670). STT injury did not induce significant astroglial response in both ipsilateral and contralateral VPL. Estradiol attenuated bilateral mechanical hypersensitivity 14 days after STT lesion (P<.05). Estradiol also suppressed microglial activation in the VPL. Taken together, these findings indicate that selective STT lesion induces bilateral microglia activation in VPL which might contribute to mechanical hypersensitivity. Furthermore, a pharmacological dose of estradiol reduces central pain possibly via suppression of glial activity in VPL region. PMID:23419864

  6. Dorsal column inhibition of nociceptive thalamic cells mediated by gamma-aminobutyric acid mechanisms in the cat.

    Science.gov (United States)

    Olausson, B; Xu, Z Q; Shyu, B C

    1994-11-01

    Cells in posterior parts of the cat thalamus were investigated. Responses in single units excited by electrical stimulation in the lateral funiculus (LF), the dorsal column nucleus (DCN) or the canine tooth pulp (TP) were analysed. All cells had a spontaneous resting activity which could be increased by extracellular iontophoretic application of DL-homocysteic acid (DLH) and decreased by gamma-aminobutyric acid (GABA). No effect on the spontaneous firing rate was observed following iontophoresis of the selective GABA-antagonists, picrotoxin (GABA-A receptor antagonist) or saclofen (GABA-B receptor antagonist). However, the decreased firing following GABA application was partially blocked by picrotoxin but not by saclofen. A phasic inhibition induced by DCN stimulation in nociceptive thalamic cells is indicated since simultaneous administration of picrotoxin increased the evoked response. This type of inhibitory mechanism could not be detected following LF or TP stimulation. The extracellular activity evoked by electrical stimulation of LF or TP was significantly depressed by preceding electrical stimulation in the DCN. This inhibition was reversed by simultaneous administration of picrotoxin, indicating an involvement of GABA-A receptors. The reversal of the DCN-induced depression of the late responses following LF stimulation occurred after application of saclofen. It is suggested that this effect is partly mediated via GABA-B receptors. Results from the present study indicate an interaction in the thalamus between presumed low-threshold (DCN) and presumed nociceptive afferents (LF and TP) similar to that previously described in the spinal cord. PMID:7872001

  7. DEEP BRAIN STIMULATION IN MIDLINE THALAMIC REGION FACILITATES SYNAPTIC TRANSMISSION AND SHORTTERM MEMORY IN A MOUSE MODEL OF ALZHEIMER'S DISEASE.

    Science.gov (United States)

    Arrieta-Cruz, Isabel; Pavlides, Constantine; Pasinetti, Giulio Maria

    2010-09-01

    Based on evidence suggesting that deep brain stimulation (DBS) may promote certain cognitive processes, we have been interested in developing DBS as a means of mitigating memory and learning impairments in Alzheimer's disease (AD). In this study we used an animal model of AD (TgCRND8 mice) to determine the effects of high-frequency stimulation (HFS) on non-amyloidogenic α-secretase activity and DBS in short-term memory. We tested our hypothesis using hippocampal slices (in vitro studies) from TgCRND8 mice to evaluate whether HFS increases α-secretase activity (non-amyloidogenic pathway) in the CA1 region. In a second set of experiments, we performed in vivo studies to evaluate whether DBS in midline thalamic region re-establishes hippocampal dependent short-term memory in TgCRND8 mice. The results showed that application of HFS to isolated hippocampal slices significantly increased synaptic plasticity in the CA1 region and promoted a 2-fold increase of non-amyloidogenic α-secretase activity, in comparison to low frequency stimulated controls from TgCRND8 mice. In the in vivo studies, DBS treatment facilitated acquisition of object recognition memory in TgCRND8 mice, in comparison to their own baseline before treatment. These results provide evidence that DBS could enhance short-term memory in the CA1 region of hippocampus in a mouse model of AD. PMID:23227306

  8. The correlation of the thalamic lesions on MRI with cerebral cortical blood flow in patients with lacunar infarction

    Energy Technology Data Exchange (ETDEWEB)

    Nabatame, Hidehiko; Nakamura, Kazuo; Matsuda, Minoru; Fujimoto, Naoki [Shiga Medical Center, Moriyama (Japan); Fukuyama, Hidenao

    1995-07-01

    We performed MRI and measured cerebral blood flow (CBF) using {sup 123}I-IMP SPECT microsphere model in twenty three right-handed patients with lacunar infarction. Twelve of 23 patients showed chronic deterioration of dysarthria and gait disturbance. The mental function of the patients was evaluated by the Mini-Mental State (MMS) examination. The area of high intensity on T2-weighted images was quantitatively analyzed in the cerebral white matter (WM), lenticular nucleus (LN) and thalamus (THA). The score of MMS was positively correlated with the local CBF in the bilateral frontal, parietal, temporal and occipital cortices (p<0.05). Also, the area of high intensity in the left THA showed a significant negative correlation with local CBF of the bilateral frontal, parietal, temporal and occipital cortices (p<0.001). The high intensity areas of the bilateral LN, right WM and right THA had a significant but weaker negative correlation with local CBF of some cortices. These findings suggest that thalamic lesions on the dominant side play an important role in the reduction of cortical blood flow and the deterioration of mental functions in patients with lacunar infarction. (author).

  9. The correlation of the thalamic lesions on MRI with cerebral cortical blood flow in patients with lacunar infarction

    International Nuclear Information System (INIS)

    We performed MRI and measured cerebral blood flow (CBF) using 123I-IMP SPECT microsphere model in twenty three right-handed patients with lacunar infarction. Twelve of 23 patients showed chronic deterioration of dysarthria and gait disturbance. The mental function of the patients was evaluated by the Mini-Mental State (MMS) examination. The area of high intensity on T2-weighted images was quantitatively analyzed in the cerebral white matter (WM), lenticular nucleus (LN) and thalamus (THA). The score of MMS was positively correlated with the local CBF in the bilateral frontal, parietal, temporal and occipital cortices (p<0.05). Also, the area of high intensity in the left THA showed a significant negative correlation with local CBF of the bilateral frontal, parietal, temporal and occipital cortices (p<0.001). The high intensity areas of the bilateral LN, right WM and right THA had a significant but weaker negative correlation with local CBF of some cortices. These findings suggest that thalamic lesions on the dominant side play an important role in the reduction of cortical blood flow and the deterioration of mental functions in patients with lacunar infarction. (author)

  10. Cash Flow Prediction Using a Grey-Box Model

    OpenAIRE

    Pang, Yang; Opong, Kwaku; Moutinho, Luia; Li, Yun

    2015-01-01

    This paper tackles the problem of financial forecasting by extending methods developed in automation, engineering and computing science. Current methods existing in the literature for firm-level cash flows are first analysed. Then a grey-box modelling method is developed to elevate the performance of cash-flow prediction. Linear panel data modelling is used as a benchmark model. Experiments with out-of-sample tests are used to validate the grey-box approach. Encouragingly, nonlinear grey-box ...

  11. Three Essays on Big-Box Retailers and Regional Economics

    OpenAIRE

    Peralta, Denis

    2016-01-01

    The big-box retail stores such as Wal-Mart and Target have become the focus of many studies researching their impacts on local economic outcomes. This dissertation studies three related topics: (i) the dynamic interrelationship among the presence of the big-box stores, retail wage, and employment, (ii) the impact of the big-box retailers on personal income growth, and (iii) the dynamic interrelationship between the presence of big-box retailers and personal income growth. The research draws i...

  12. Ion-wake Field inside a Glass Box

    CERN Document Server

    Chen, Mudi; Zhang, Bo; Matthews, Lorin S; Hyde, Truell W

    2016-01-01

    The confinement provided by a glass box is proving ideal for the formation of vertically aligned structures and a convenient method for controlling the number of dust particles comprising these dust structures, as well as their size and shape. In this paper, the electronic confinement of the glass box is mapped and the particle interactions between the particle pairs inside the glass box are measured. The ion-wake field is shown to exist within the glass box and its vertical and horizontal extent is measured.

  13. New approaches to glove box design at Hanford

    International Nuclear Information System (INIS)

    Glove boxes provide the primary environmental containment system for plutonium processing operations at US Dept. of Energy (DOE)-owned facilities such as Rockwell Hanford. As noted in previous presentations, glove box designs and operations have evolved through stages that are a result of advances in processing techniques, new regulatory requirements, and cost escalation. These factors will continue to influence the current glove box designs and operations. The purpose of this presentation is to discuss required upgrades and changes that are being incorporated into glove boxes being installed at Rockwell Hanford and other DOE installations or are being evaluated for future upgrades

  14. Expression of dopamine D2 receptor in PC-12 cells and regulation of membrane conductances by dopamine.

    Science.gov (United States)

    Zhu, W H; Conforti, L; Millhorn, D E

    1997-10-01

    PC-12 cells depolarize during hypoxia and release dopamine. The hypoxia-induced depolarization is due to inhibition of an O2-sensitive K+ current. The role of dopamine released during hypoxia is uncertain, but it could act as an autocrine to modulate membrane conductance during hypoxia. The current study was undertaken to investigate this possibility. Reverse transcription-polymerase chain reaction and sequence analysis revealed that the D2 isoform of the dopamine receptor is expressed in rat PC-12 cells. Exogenously applied dopamine and the D2 agonist quinpirole elicited inhibition of a voltage-dependent K+ current (I(K)) that was prevented by sulpiride, a D2 receptor antagonist. Dopamine and quinpirole applied during hypoxia potentiated the inhibitory effect of hypoxia on I(K). We also found that quinpirole caused reversible inhibition of a voltage-dependent Ca2+ current (I(Ca)) and attenuation of the increase in intracellular free Ca2+ during hypoxia. Our results indicate that dopamine released from PC-12 cells during hypoxia acts via a D2 receptor to "autoregulate" I(K) and I(Ca). PMID:9357757

  15. Visualizing dopamine released from living cells using a nanoplasmonic probe

    Science.gov (United States)

    Qin, W. W.; Wang, S. P.; Li, J.; Peng, T. H.; Xu, Y.; Wang, K.; Shi, J. Y.; Fan, C. H.; Li, D.

    2015-09-01

    We report the development of an ultrasensitive nanoplasmonic probe for discriminative detection and imaging of dopamine released from living cells. The sensing mechanism is based on the dopamine-induced seeded-growth of Au nanoparticles (Au NPs) that leads to the shift of the plasmon band. This platform allows for the detection of dopamine with a detection limit down to 0.25 pM within 1 min. This nanoplasmonic assay is further applied to visualize the release of dopamine from living rat pheochromocytoma (PC12) cells under ATP-stimulation with dark-field microscopy (DFM). The DFM results together with real time fluorescence imaging of PC12 cells stained with the Fluo calcium indicator, suggested that ATP stimulated-release of dopamine is concomitant with the Ca2+ influx, and the influx of Ca2+ is through ATP-activated channels instead of the voltage-gated Ca2+ channel (VGC).We report the development of an ultrasensitive nanoplasmonic probe for discriminative detection and imaging of dopamine released from living cells. The sensing mechanism is based on the dopamine-induced seeded-growth of Au nanoparticles (Au NPs) that leads to the shift of the plasmon band. This platform allows for the detection of dopamine with a detection limit down to 0.25 pM within 1 min. This nanoplasmonic assay is further applied to visualize the release of dopamine from living rat pheochromocytoma (PC12) cells under ATP-stimulation with dark-field microscopy (DFM). The DFM results together with real time fluorescence imaging of PC12 cells stained with the Fluo calcium indicator, suggested that ATP stimulated-release of dopamine is concomitant with the Ca2+ influx, and the influx of Ca2+ is through ATP-activated channels instead of the voltage-gated Ca2+ channel (VGC). Electronic supplementary information (ESI) available: Fig. S1-S4 and Table S1. See DOI: 10.1039/c5nr04433b

  16. SPECT imaging of D2 dopamine receptors and endogenous dopamine release in mice

    International Nuclear Information System (INIS)

    The dopamine D2 receptor (D2R) is important in the mediation of addiction. [123I]iodobenzamide (IBZM), a SPECT ligand for the D2R, has been used for in vivo studies of D2R availability in humans, monkeys, and rats. Although mouse models are important in the study of addiction, [123I]IBZM has not been used in mice SPECT studies. This study evaluates the use of [123I]IBZM for measuring D2R availability in mice. Pharmacokinetics of [123I]IBZM in mice were studied with pinhole SPECT imaging after intravenous (i.v.) injection of [123I]IBZM (20, 40, and 70 MBq). In addition, the ability to measure the release of endogenous dopamine after amphetamine administration with [123I]IBZM SPECT was investigated. Thirdly, i.v. administration, the standard route of administration, and intraperitoneal (i.p.) administration of [123I]IBZM were compared. Specific binding of [123I]IBZM within the mouse striatum could be clearly visualized with SPECT. Peak specific striatal binding ratios were reached around 90 min post-injection. After amphetamine administration, the specific binding ratios of [123I]IBZM decreased significantly (-27.2%; n=6; p=0.046). Intravenous administration of [123I]IBZM led to significantly higher specific binding than i.p. administration of the same dose. However, we found that i.v. administration of a dose of 70 MBq [123I]IBZM might result in acute ethanol intoxication because ethanol is used as a preparative aid for the routine production of [123I]IBZM. Imaging of D2R availability and endogenous dopamine release in mice is feasible using [123I]IBZM single pinhole SPECT. Using commercially produced [123I]IBZM, a dose of 40 MBq injected i.v. can be recommended. (orig.)

  17. De novo mutation in the dopamine transporter gene associates dopamine dysfunction with autism spectrum disorder

    DEFF Research Database (Denmark)

    Hamilton, P J; Campbell, N G; Sharma, S;

    2013-01-01

    De novo genetic variation is an important class of risk factors for autism spectrum disorder (ASD). Recently, whole-exome sequencing of ASD families has identified a novel de novo missense mutation in the human dopamine (DA) transporter (hDAT) gene, which results in a Thr to Met substitution at......, substitution of A289 (the homologous site to T356) with a Met promotes an outward-facing conformation upon substrate binding. In the substrate-bound state, an outward-facing transporter conformation is required for substrate efflux. In Drosophila melanogaster, the expression of hDAT T356M in DA neurons...

  18. Dopamine receptor-mediated regulation of neuronal "clock" gene expression.

    Science.gov (United States)

    Imbesi, M; Yildiz, S; Dirim Arslan, A; Sharma, R; Manev, H; Uz, T

    2009-01-23

    Using a transgenic mice model (i.e. "clock" knockouts), clock transcription factors have been suggested as critical regulators of dopaminergic behaviors induced by drugs of abuse. Moreover, it has been shown that systemic administration of psychostimulants, such as cocaine and methamphetamine regulates the striatal expression of clock genes. However, it is not known whether dopamine receptors mediate these regulatory effects of psychostimulants at the cellular level. Primary striatal neurons in culture express dopamine receptors as well as clock genes and have been successfully used in studying dopamine receptor functioning. Therefore, we investigated the role of dopamine receptors on neuronal clock gene expression in this model using specific receptor agonists. We found an inhibitory effect on the expression of mClock and mPer1 genes with the D2-class (i.e. D2/D3) receptor agonist quinpirole. We also found a generalized stimulatory effect on the expression of clock genes mPer1, mClock, mNPAS2 (neuronal PAS domain protein 2), and mBmal1 with the D1-class (i.e. D1) receptor agonist SKF38393. Further, we tested whether systemic administration of dopamine receptor agonists causes similar changes in striatal clock gene expression in vivo. We found quinpirole-induced alterations in mPER1 protein levels in the mouse striatum (i.e. rhythm shift). Collectively, our results indicate that the dopamine receptor system may mediate psychostimulant-induced changes in clock gene expression. Using striatal neurons in culture as a model, further research is needed to better understand how dopamine signaling modulates the expression dynamics of clock genes (i.e. intracellular signaling pathways) and thereby influences neuronal gene expression, neuronal transmission, and brain functioning. PMID:19017537

  19. Somatodendritic dopamine release: recent mechanistic insights.

    Science.gov (United States)

    Rice, Margaret E; Patel, Jyoti C

    2015-07-01

    Dopamine (DA) is a key transmitter in motor, reward and cogitative pathways, with DA dysfunction implicated in disorders including Parkinson's disease and addiction. Located in midbrain, DA neurons of the substantia nigra pars compacta project via the medial forebrain bundle to the dorsal striatum (caudate putamen), and DA neurons in the adjacent ventral tegmental area project to the ventral striatum (nucleus accumbens) and prefrontal cortex. In addition to classical vesicular release from axons, midbrain DA neurons exhibit DA release from their cell bodies and dendrites. Somatodendritic DA release leads to activation of D2 DA autoreceptors on DA neurons that inhibit their firing via G-protein-coupled inwardly rectifying K(+) channels. This helps determine patterns of DA signalling at distant axonal release sites. Somatodendritically released DA also acts via volume transmission to extrasynaptic receptors that modulate local transmitter release and neuronal activity in the midbrain. Thus, somatodendritic release is a pivotal intrinsic feature of DA neurons that must be well defined in order to fully understand the physiology and pathophysiology of DA pathways. Here, we review recent mechanistic aspects of somatodendritic DA release, with particular emphasis on the Ca(2+) dependence of release and the potential role of exocytotic proteins. PMID:26009764

  20. The role of dopamine signaling in epileptogenesis.

    Science.gov (United States)

    Bozzi, Yuri; Borrelli, Emiliana

    2013-01-01

    Clinical and experimental studies implicate most neuromodulatory systems in epileptogenesis. The dopaminergic system has a seizure-modulating effect that crucially depends on the different subtypes of dopamine (DA) receptors involved and the brain regions in which they are activated. Specifically, DA plays a major role in the control of seizures arising in the limbic system. Studies performed in a wide variety of animal models contributed to illustrate the opposite actions of D1-like and D2-like receptor signaling in limbic epileptogenesis. Indeed, signaling from D1-like receptors is generally pro-epileptogenic, whereas D2-like receptor signaling exerts an anti-epileptogenic effect. However, this view might appear quite simplistic as the complex neuromodulatory action of DA in the control of epileptogenesis likely requires a physiological balance in the activation of circuits modulated by these two major DA receptor subtypes, which determines the response to seizure-promoting stimuli. Here we will review recent evidences on the identification of molecules activated by DA transduction pathways in the generation and spread of seizures in the limbic system. We will discuss the intracellular signaling pathways triggered by activation of different DA receptors in relation to their role in limbic epileptogenesis, which lead to the activation of neuronal death/survival cascades. A deep understanding of the signaling pathways involved in epileptogenesis is crucial for the identification of novel targets for the treatment of epilepsy. PMID:24062645