The presence of nuclear cactus in the early Drosophila embryo may extend the dynamic range of the dorsal gradient.

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Michael D O'Connell

2015-04-01

Full Text Available In a developing embryo, the spatial distribution of a signaling molecule, or a morphogen gradient, has been hypothesized to carry positional information to pattern tissues. Recent measurements of morphogen distribution have allowed us to subject this hypothesis to rigorous physical testing. In the early Drosophila embryo, measurements of the morphogen Dorsal, which is a transcription factor responsible for initiating the earliest zygotic patterns along the dorsal-ventral axis, have revealed a gradient that is too narrow to pattern the entire axis. In this study, we use a mathematical model of Dorsal dynamics, fit to experimental data, to determine the ability of the Dorsal gradient to regulate gene expression across the entire dorsal-ventral axis. We found that two assumptions are required for the model to match experimental data in both Dorsal distribution and gene expression patterns. First, we assume that Cactus, an inhibitor that binds to Dorsal and prevents it from entering the nuclei, must itself be present in the nuclei. And second, we assume that fluorescence measurements of Dorsal reflect both free Dorsal and Cactus-bound Dorsal. Our model explains the dynamic behavior of the Dorsal gradient at lateral and dorsal positions of the embryo, the ability of Dorsal to regulate gene expression across the entire dorsal-ventral axis, and the robustness of gene expression to stochastic effects. Our results have a general implication for interpreting fluorescence-based measurements of signaling molecules.

Neuromelanin imaging and midbrain volumetry in progressive supranuclear palsy and Parkinson's disease.

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Taniguchi, Daisuke; Hatano, Taku; Kamagata, Koji; Okuzumi, Ayami; Oji, Yutaka; Mori, Akio; Hori, Masaaki; Aoki, Shigeki; Hattori, Nobutaka

2018-05-14

Background Nigral degeneration patterns differ between PSP and PD. However, the relationship between nigral degeneration and midbrain atrophy in PSP remains unclear. Objective We analyzed differences and relationships between nigral degeneration and midbrain atrophy in PSP and PD. Methods Neuromelanin-sensitive MRI and midbrain volumetry were performed in 11 PSP patients, 24 PD patients, and 10 controls to measure the neuromelanin-sensitive SNpc area and midbrain volume. Results The neuromelanin-sensitive SNpc area and midbrain volume were significantly smaller in PSP patients compared with PD patients and controls. Motor deficits were inversely correlated with neuromelanin-sensitive SNpc area in PD, but not PSP patients. There was no significant correlation between neuromelanin-sensitive SNpc area and midbrain volume in either disease group. Midbrain volumetry discriminated PSP from PD. Diagnostic accuracy was improved when neuromelanin-sensitive MRI analysis was added. Conclusions Neuromelanin-sensitive MRI and midbrain volumetry may reflect the clinical and pathological characteristics of PSP and PD. Combining neuromelanin-sensitive MRI and midbrain volumetry may be useful for differentiating PSP from PD. © 2018 International Parkinson and Movement Disorder Society. © 2018 International Parkinson and Movement Disorder Society.

Laterotopic representation of left-right information onto the dorso-ventral axis of a zebrafish midbrain target nucleus.

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Aizawa, Hidenori; Bianco, Isaac H; Hamaoka, Takanori; Miyashita, Toshio; Uemura, Osamu; Concha, Miguel L; Russell, Claire; Wilson, Stephen W; Okamoto, Hitoshi

2005-02-08

The habenulae are part of an evolutionarily highly conserved limbic-system conduction pathway that connects telencephalic nuclei to the interpeduncular nucleus (IPN) of the midbrain . In zebrafish, unilateral activation of the Nodal signaling pathway in the left brain specifies the laterality of the asymmetry of habenular size . We show "laterotopy" in the habenulo-interpeduncular projection in zebrafish, i.e., the stereotypic, topographic projection of left-sided habenular axons to the dorsal region of the IPN and of right-sided habenular axons to the ventral IPN. This asymmetric projection is accounted for by a prominent left-right (LR) difference in the size ratio of the medial and lateral habenular sub-nuclei, each of which specifically projects either to ventral or dorsal IPN targets. Asymmetric Nodal signaling directs the orientation of laterotopy but is dispensable for the establishment of laterotopy itself. Our results reveal a mechanism by which information distributed between left and right sides of the brain can be transmitted bilaterally without loss of LR coding, which may play a crucial role in functional lateralization of the vertebrate brain .

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Opioid receptors in midbrain dopaminergic regions of the rat. 1. Mu receptor autoradiography

International Nuclear Information System (INIS)

German, D.C.; Speciale, S.G.; Manaye, K.F.; Sadeq, M.

1993-01-01

Several lines of evidence indicate that an interaction exists between opioid peptides and midbrain dopaminergic neurons. The purpose of this study was to map and quantify the density of the mu opioid receptor subtype relative to the location of the dopaminergic (DA) neurons in the retrorubral field (nucleus A8), substantia nigra (nucleus A9), and ventral tegmental area and related nuclei (nucleus A10) in the rat. Sections through the rostral-caudal extent of the midbrain were stained with an antibody against tyrosine hydroxylase, as a DA cell marker, and comparable sections were processed for in vitro receptor autoradiography using the mu-selective ligand, 3 H-Tyr-D-Ala-N-MePhe-Gyl-ol enkephalin. In the nucleus A8 region, there were low levels of mu binding. In the rostral portion of nucleus A9, there was prominent mu binding both in the ventral pars compacta, which contains numerous DA neurons, and in regions that correspond to the location of the DA dendrites which project ventrally into the underlying substantia nigra pars reticulata. In the caudal portion of nucleus A9, mu binding was greatest in the substantia nigra pars reticulata, but also in the same region that contains DA neurons. In nucleus A10, mu receptor densities differed depending upon the nucleus A10 subdivision, and the rostral-caudal position in the nucleus. Low receptor densities were observed in rostral portions of the ventral tegmental area and interfascicular nucleus, and there was negligible binding in the parabrachial pigmented nucleus and paranigral nucleus at the level of the interpeduncular nucleus; all regions where there are high densities of DA somata. Mu binding was relatively high in the central linear nucleus, and in the dorsal and medial divisions of the medial terminal nucleus of the accessory optic system, which has been shown to contain DA dendrites. These data indicate that mu opioid receptors are located in certain regions occupied by all three midbrain DA nuclei, but in a

VMAT2-mediated neurotransmission from midbrain leptin receptor neurons in feeding regulation

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Leptin receptors (LepRs) expressed in the midbrain contribute to the action of leptin on feeding regulation. The midbrain neurons release a variety of neurotransmitters including dopamine (DA), glutamate and GABA. However, which neurotransmitter mediates midbrain leptin action on feeding remains unc...

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Predicting Early Reading Skills from Pre-Reading Measures of Dorsal Stream Functioning

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Kevan, Alison; Pammer, Kristen

2009-01-01

It is well documented that good reading skills may be dependent upon adequate dorsal stream processing. However, the degree to which dorsal stream deficits play a causal role in reading failure has not been established. This study used coherent motion and visual frequency doubling to examine whether dorsal stream sensitivity measured before the…

The developing dorsal ganglion of the salp Thalia democratica, and the nature of the ancestral chordate brain

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C.Lacalli, T.

1998-01-01

The development of the dorsal ganglion of the salp, Thalia democratica, is described from electron microscope reconstructions up to the stage of central neuropile formation. The central nervous system (CNS) rudiment is initially tubular with an open central canal. Early developmental events include: (i) the formation of a thick dorsal mantle of neuroblasts from which paired dorsal paraxial neuropiles arise; (ii) the differentiation of clusters of primary motor neurons along the ventral margin of the mantle; and (iii) the development from the latter of a series of peripheral nerves. The dorsal paraxial neuropiles ultimately connect to the large central neuropile, which develops later. Direct contact between neuroblasts and muscle appears to be involved in the development of some anterior nerves. The caudal nerves responsible for innervating more distant targets in the posterior part of the body develop without such contacts, which suggests that a different patterning mechanism may be employed in this part of the neuromuscular system. The results are compared with patterns of brain organization in other chordates. Because the salp CNS is symmetrical and generally less reduced than that of ascidian larvae, it is more easily compared with the CNS of amphioxus and vertebrates. The dorsal paraxial centres in the salp resemble the dorsolateral tectal centres in amphioxus in both position and organization; the central neuropile in salps likewise resembles the translumenal system in amphioxus. The neurons themselves are similar in that many of their neurites appear to be derived from the apical surface instead of the basal surface of the cell. Such neurons, with extensively developed apical neurites, may represent a new cell type that evolved in the earliest chordates in conjunction with the formation of translumenal or intralumenal integrative centres. In comparing the salp ganglion with vertebrates, we suggest that the main core of the ganglion is most like the mes

Obstructive sleep apnea is associated with altered midbrain chemical concentrations.

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Macey, Paul M; Sarma, Manoj K; Prasad, Janani P; Ogren, Jennifer A; Aysola, Ravi; Harper, Ronald M; Thomas, M Albert

2017-11-05

Obstructive sleep apnea (OSA) is accompanied by altered structure and function in cortical, limbic, brainstem, and cerebellar regions. The midbrain is relatively unexamined, but contains many integrative nuclei which mediate physiological functions that are disrupted in OSA. We therefore assessed the chemistry of the midbrain in OSA in this exploratory study. We used a recently developed accelerated 2D magnetic resonance spectroscopy (2D-MRS) technique, compressed sensing-based 4D echo-planar J-resolved spectroscopic imaging (4D-EP-JRESI), to measure metabolites in the midbrain of 14 OSA (mean age±SD:54.6±10.6years; AHI:35.0±19.4; SAO 2 min:83±7%) and 26 healthy control (50.7±8.5years) subjects. High-resolution T1-weighted scans allowed voxel localization. MRS data were processed with custom MATLAB-based software, and metabolite ratios calculated with respect to the creatine peak using a prior knowledge fitting (ProFit) algorithm. The midbrain in OSA showed decreased N-acetylaspartate (NAA; OSA:1.24±0.43, Control:1.47±0.41; p=0.03; independent samples t-test), a marker of neuronal viability. Increased levels in OSA over control subjects appeared in glutamate (Glu; OSA:1.23±0.57, Control:0.98±0.33; p=0.03), ascorbate (Asc; OSA:0.56±0.28, Control:0.42±0.20; (50.7±8.5years; p=0.03), and myo-inositol (mI; OSA:0.96±0.48, Control:0.72±0.35; p=0.03). No differences between groups appeared in γ-aminobutyric acid (GABA) or taurine. The midbrain in OSA patients shows decreased NAA, indicating neuronal injury or dysfunction. Higher Glu levels may reflect excitotoxic processes and astrocyte activation, and higher mI is also consistent with glial activation. Higher Asc levels may result from oxidative stress induced by intermittent hypoxia in OSA. Additionally, Asc and Glu are involved with glutamatergic processes, which are likely upregulated in the midbrain nuclei of OSA patients. The altered metabolite levels help explain dysfunction and structural deficits in

The dorsal shell wall structure of Mesozoic ammonoids

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Gregor Radtke

2017-03-01

Full Text Available The study of pristine preserved shells of Mesozoic Ammonoidea shows different types of construction and formation of the dorsal shell wall. We observe three major types: (i The vast majority of Ammonoidea, usually planispirally coiled, has a prismatic reduced dorsal shell wall which consists of an outer organic component (e.g., wrinkle layer, which is the first layer to be formed, and the subsequently formed dorsal inner prismatic layer. The dorsal mantle tissue suppresses the formation of the outer prismatic layer and nacreous layer. With the exception of the outer organic component, secretion of a shell wall is omitted at the aperture. A prismatic reduced dorsal shell wall is always secreted immediately after the hatching during early teleoconch formation. Due to its broad distribution in (planispiral Ammonoidea, the prismatic reduced dorsal shell wall is probably the general state. (ii Some planispirally coiled Ammonoidea have a nacreous reduced dorsal shell wall which consists of three mineralized layers: two prismatic layers (primary and secondary dorsal inner prismatic layer and an enclosed nacreous layer (secondary dorsal nacreous layer. The dorsal shell wall is omitted at the aperture and was secreted in the rear living chamber. Its layers are a continuation of an umbilical shell doubling (reinforcement by additional shell layers that extends towards the ventral crest of the preceding whorl. The nacreous reduced dorsal shell wall is formed in the process of ontogeny following a prismatic reduced dorsal shell wall. (iii Heteromorph and some planispirally coiled taxa secrete a complete dorsal shell wall which forms a continuation of the ventral and lateral shell layers. It is formed during ontogeny following a prismatic reduced dorsal shell wall or a priori. The construction is identical with the ventral and lateral shell wall, including a dorsal nacreous layer. The wide distribution of the ability to form dorsal nacre indicates that it is

Specificity and impact of adrenergic projections to the midbrain dopamine system

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Mejias-Aponte, Carlos A.

2016-01-01

Dopamine (DA) is a neuromodulator that regulates different brain circuits involved in cognitive functions, motor coordination, and emotions. Dysregulation of DA is associated with many neurological and psychiatric disorders such as Parkinson’s disease and substance abuse. Several lines of research have shown that the midbrain DA system is regulated by the central adrenergic system. This review focuses on adrenergic interactions with midbrain DA neurons. It discusses the current neuroanatomy including source of adrenergic innervation, type of synapses, and adrenoceptors expression. It also discusses adrenergic regulation of DA cell activity and neurotransmitter release. Finally, it reviews several neurological and psychiatric disorders where changes in adrenergic system are associated with dysregulation of the midbrain DA system. PMID:26820641

Clinical Value of Dorsal Medulla Oblongata Involvement Detected with Conventional MRI for Prediction of Outcome in Children with Enterovirus 71-related Brainstem Encephalitis.

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Liu, Kun; Zhou, Yongjin; Cui, Shihan; Song, Jiawen; Ye, Peipei; Xiang, Wei; Huang, Xiaoyan; Chen, Yiping; Yan, Zhihan; Ye, Xinjian

2018-04-05

Brainstem encephalitis is the most common neurologic complication after enterovirus 71 infection. The involvement of brainstem, especially the dorsal medulla oblongata, can cause severe sequelae or death in children with enterovirus 71 infection. We aimed to determine the prevalence of dorsal medulla oblongata involvement in children with enterovirus 71-related brainstem encephalitis (EBE) by using conventional MRI and to evaluate the value of dorsal medulla oblongata involvement in outcome prediction. 46 children with EBE were enrolled in the study. All subjects underwent a 1.5 Tesla MR examination of the brain. The disease distribution and clinical data were collected. Dichotomized outcomes (good versus poor) at longer than 6 months were available for 28 patients. Logistic regression was used to determine whether the MRI-confirmed dorsal medulla oblongata involvement resulted in improved clinical outcome prediction when compared with other location involvement. Of the 46 patients, 35 had MRI evidence of dorsal medulla oblongata involvement, 32 had pons involvement, 10 had midbrain involvement, and 7 had dentate nuclei involvement. Patients with dorsal medulla oblongata involvement or multiple area involvement were significantly more often in the poor outcome group than in the good outcome group. Logistic regression analysis showed that dorsal medulla oblongata involvement was the most significant single variable in outcome prediction (predictive accuracy, 90.5%), followed by multiple area involvement, age, and initial glasgow coma scale score. Dorsal medulla oblongata involvement on conventional MRI correlated significantly with poor outcomes in EBE children, improved outcome prediction when compared with other clinical and disease location variables, and was most predictive when combined with multiple area involvement, glasgow coma scale score and age.

Opposing dorsal/ventral stream dynamics during figure-ground segregation.

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Wokke, Martijn E; Scholte, H Steven; Lamme, Victor A F

2014-02-01

The visual system has been commonly subdivided into two segregated visual processing streams: The dorsal pathway processes mainly spatial information, and the ventral pathway specializes in object perception. Recent findings, however, indicate that different forms of interaction (cross-talk) exist between the dorsal and the ventral stream. Here, we used TMS and concurrent EEG recordings to explore these interactions between the dorsal and ventral stream during figure-ground segregation. In two separate experiments, we used repetitive TMS and single-pulse TMS to disrupt processing in the dorsal (V5/HMT⁺) and the ventral (lateral occipital area) stream during a motion-defined figure discrimination task. We presented stimuli that made it possible to differentiate between relatively low-level (figure boundary detection) from higher-level (surface segregation) processing steps during figure-ground segregation. Results show that disruption of V5/HMT⁺ impaired performance related to surface segregation; this effect was mainly found when V5/HMT⁺ was perturbed in an early time window (100 msec) after stimulus presentation. Surprisingly, disruption of the lateral occipital area resulted in increased performance scores and enhanced neural correlates of surface segregation. This facilitatory effect was also mainly found in an early time window (100 msec) after stimulus presentation. These results suggest a "push-pull" interaction in which dorsal and ventral extrastriate areas are being recruited or inhibited depending on stimulus category and task demands.

Evidence of functional duplicity of Nestin expression in the adult mouse midbrain

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Parisa Farzanehfar

2017-03-01

. Remarkably, as early as 4 days following putative Nestin-expression, many β-gal+ or eYFP+ cells had mature neuronal morphology and were NeuN+. Furthermore, mature neuronal β-gal+ cells were immunoreactive against the self-renewal or pluripotency marker sex determining region Y-box 2 (Sox2. Overall, our data support the notion that some Nestin-expressing, presumably NPCs, have a limited capacity for proliferation, no capacity for migration, and a propensity to generate new neurons within the microenvironment of the adult midbrain. However, our data also suggest that significant numbers of extant midbrain neurons express Nestin and other classical neurogenesis markers in contexts that are presumably not neurogenic. These findings foreshadow duplicitous roles for Nestin and other molecules that are traditionally associated with neurogenesis in the adult midbrain, which should be considered in future PD research.

Midbrain and forebrain patterning delivers immunocytochemically and functionally similar populations of neuropeptide Y containing GABAergic neurons.

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Khaira, S K; Nefzger, C M; Beh, S J; Pouton, C W; Haynes, J M

2011-09-01

Neurons differentiated in vitro from embryonic stem cells (ESCs) have the potential to serve both as models of disease states and in drug discovery programs. In this study, we use sonic hedgehog (SHH) and fibroblast growth factor 8 (FGF-8) to enrich for forebrain and midbrain phenotypes from mouse ESCs. We then investigate, using Ca(2+) imaging and [(3)H]-GABA release studies, whether the GABAergic neurons produced exhibit distinct functional phenotypes. At day 24 of differentiation, reverse transcriptase-PCR showed the presence of both forebrain (Bf-1, Hesx1, Pgc-1α, Six3) and midbrain (GATA2, GATA3) selective mRNA markers in developing forebrain-enriched cultures. All markers were present in midbrain cultures except for Bf-1 and Pgc-1α. Irrespective of culture conditions all GABA immunoreactive neurons were also immunoreactive to neuropeptide Y (NPY) antibodies. Forebrain and midbrain GABAergic neurons responded to ATP (1 mM), L-glutamate (30 μM), noradrenaline (30 μM), acetylcholine (30 μM) and dopamine (30 μM), with similar elevations of intracellular Ca(2+)([Ca(2+)](i)). The presence of GABA(A) and GABA(B) antagonists, bicuculline (30 μM) and CGP55845 (1 μM), increased the elevation of [Ca(2+)](i) in response to dopamine (30 μM) in midbrain, but not forebrain GABAergic neurons. All agonists, except dopamine, elicited similar [(3)H]-GABA release from forebrain and midbrain cultures. Dopamine (30 μM) did not stimulate significant [(3)H]-GABA release in midbrain cultures, although it was effective in forebrain cultures. This study shows that differentiating neurons toward a midbrain fate restricts the expression of forebrain markers. Forebrain differentiation results in the expression of forebrain and midbrain markers. All GABA(+) neurons contain NPY, and show similar agonist-induced elevations of [Ca(2+)](i) and [(3)H]-GABA release. This study indicates that the pharmacological phenotype of these particular neurons may be independent of the addition of

A Case of Midbrain and Thalamic Infarction Involving Artery of Percheron

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Muhammad Almamun

2015-03-01

Full Text Available Blood supply to the thalamus and brainstem have frequent anatomic variations. One of these is where all the perforators to the above areas arise from a single branch of the posterior cerebral artery commonly known as the artery of Percheron. Infarction involving this artery leading to bilateral thalamic and midbrain lesions is not uncommon, but can cause diagnostic difficulties due to the varying clinical presentations possible and the wide differentials. Early brain imaging and diagnosis is important for initiating appropriate treatment. In this case report, we discuss a patient who presented with an artery of Percheron related stroke affecting the mid brain and paramedian thalamic areas. We also discuss the differentials of presentations with similar symptoms.

Tualang Honey Protects the Rat Midbrain and Lung against Repeated Paraquat Exposure.

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Tang, Suk Peng; Kuttulebbai Nainamohamed Salam, Sirajudeen; Jaafar, Hasnan; Gan, Siew Hua; Muzaimi, Mustapha; Sulaiman, Siti Amrah

2017-01-01

Paraquat (PQ) is a dopaminergic neurotoxin and a well-known pneumotoxicant that exerts its toxic effect via oxidative stress-mediated cellular injuries. This study investigated the protective effects of Tualang honey against PQ-induced toxicity in the midbrain and lungs of rats. The rats were orally treated with distilled water (2 mL/kg/day), Tualang honey (1.0 g/kg/day), or ubiquinol (0.2 g/kg/day) throughout the experimental period. Two weeks after the respective treatments, the rats were injected intraperitoneally with saline (1 mL/kg/week) or PQ (10 mg/kg/week) once per week for four consecutive weeks. After four weekly exposures to PQ, the glutathione peroxidase activity and the number of tyrosine-hydroxylase immunopositive neurons in the midbrain were significantly decreased in animals from group PQ ( p honey ameliorated the toxic effects observed in the midbrain and lungs. The beneficial effects of Tualang honey were comparable to those of ubiquinol, which was used as a positive control. These findings suggest that treatment with Tualang honey may protect against PQ-induced toxicity in the rat midbrain and lung.

Tualang Honey Protects the Rat Midbrain and Lung against Repeated Paraquat Exposure

Science.gov (United States)

Sulaiman, Siti Amrah

2017-01-01

Paraquat (PQ) is a dopaminergic neurotoxin and a well-known pneumotoxicant that exerts its toxic effect via oxidative stress-mediated cellular injuries. This study investigated the protective effects of Tualang honey against PQ-induced toxicity in the midbrain and lungs of rats. The rats were orally treated with distilled water (2 mL/kg/day), Tualang honey (1.0 g/kg/day), or ubiquinol (0.2 g/kg/day) throughout the experimental period. Two weeks after the respective treatments, the rats were injected intraperitoneally with saline (1 mL/kg/week) or PQ (10 mg/kg/week) once per week for four consecutive weeks. After four weekly exposures to PQ, the glutathione peroxidase activity and the number of tyrosine-hydroxylase immunopositive neurons in the midbrain were significantly decreased in animals from group PQ (p honey ameliorated the toxic effects observed in the midbrain and lungs. The beneficial effects of Tualang honey were comparable to those of ubiquinol, which was used as a positive control. These findings suggest that treatment with Tualang honey may protect against PQ-induced toxicity in the rat midbrain and lung. PMID:28127418

Movement disorders associated with focal midbrain lesion: correlation with clinical and I-123 IPT SPECT findings

International Nuclear Information System (INIS)

Kang, Ji Hoon; Im, Joo Hyuk; Kim, Jae Seung; Lee, Myoung Chong

2001-01-01

Midbrain lesion may produce a variety of movement disorders including tremor, dystonia, and parkinsonism. The anatomical and functional basis of the movement disorder associated with the midbrain lesion is still unclear. The purpose of this study was to correlate focal midbrain lesions with clinical and I-123 IPT SPECT findings. Five patients (aged 25 to 69 years, 3 men and 2 women) who presented with movement disorder associated with discrete focal midbrain lesion on the brain MRI were included. We reviewed the clinical characteristics of movement disorders and the brain MRI findings in all patients. I-123 IPT SPECT was performed in all patients and 9 normal controls to evaluate the integrity of the nigrostriatal dopaminergic system and specific binding ratios were also calculated. Patients consisted of 2 with parkinsonism, 1 with midbrain tremor, 1 with hemidystonia, and 1 with micrographia as the only manifestation. In all patients, movement disorders were confined to the limbs contralateral to the focal midbrain lesions. The causes of midbrain lesion were trauma (n=2), rupture of AVM (n=1), cerebral infarction (n=1), and encephalitis (n=1). The latency between the midbrain injury and the onset of movement disorder varied from 1.5 months to 2 years (mean 6.7 months). Specific binding ratios of ipsilateral striatum (1.6±1.4) were significantly lower than that of contralateral side (3.3±0.99) and normal control (3.5±0.5)(p<0.05). All of six patients had lesions involving substantia nigra on MRI and two of these with resting tremor had also lesions involving the red nucleus. Bradykinesia and rigidity were mild or absent in these two patients, despite severely decreased specific binding ratios (mean 0.55) of ipsilateral striatum. Movement disorders associated with focal midbrain lesion were partially related to the damage in the nigrostriatal dopaminergic system. However, the severity and nature of movement disorder were variable and not directly related to the

Enduring, Sexually Dimorphic Impact of In Utero Exposure to Elevated Levels of Glucocorticoids on Midbrain Dopaminergic Populations

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Glenda E. Gillies

2016-12-01

Full Text Available Glucocorticoid hormones (GCs released from the fetal/maternal glands during late gestation are required for normal development of mammalian organs and tissues. Accordingly, synthetic glucocorticoids have proven to be invaluable in perinatal medicine where they are widely used to accelerate fetal lung maturation when there is risk of pre-term birth and to promote infant survival. However, clinical and pre-clinical studies have demonstrated that inappropriate exposure of the developing brain to elevated levels of GCs, either as a result of clinical over-use or after stress-induced activation of the fetal/maternal adrenal cortex, is linked with significant effects on brain structure, neurological function and behaviour in later life. In order to understand the underlying neural processes, particular interest has focused on the midbrain dopaminergic systems, which are critical regulators of normal adaptive behaviours, cognitive and sensorimotor functions. Specifically, using a rodent model of GC exposure in late gestation (approximating human brain development at late second/early third trimester, we demonstrated enduring effects on the shape and volume of the ventral tegmental area (VTA and substantia nigra pars compacta (SNc (origins of the mesocorticolimbic and nigrostriatal dopaminergic pathways on the topographical organisation and size of the dopaminergic neuronal populations and astrocytes within these nuclei and on target innervation density and neurochemical markers of dopaminergic transmission (receptors, transporters, basal and amphetamine-stimulated dopamine release at striatal and prefrontal cortical sites that impact on the adult brain. The effects of antenatal GC treatment (AGT were both profound and sexually-dimorphic, not only in terms of quantitative change but also qualitatively, with several parameters affected in the opposite direction in males and females. Although such substantial neurobiological changes might presage marked

Encoding of natural and artificial stimuli in the auditory midbrain

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Lyzwa, Dominika

How complex acoustic stimuli are encoded in the main center of convergence in the auditory midbrain is not clear. Here, the representation of neural spiking responses to natural and artificial sounds across this subcortical structure is investigated based on neurophysiological recordings from the mammalian midbrain. Neural and stimulus correlations of neuronal pairs are analyzed with respect to the neurons' distance, and responses to different natural communication sounds are discriminated. A model which includes linear and nonlinear neural response properties of this nucleus is presented and employed to predict temporal spiking responses to new sounds. Supported by BMBF Grant 01GQ0811.

Parkinson's disease-like midbrain hyperechogenicity is frequent in amyotrophic lateral sclerosis.

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Fathinia, Panteha; Hermann, Andreas; Reuner, Ulrike; Kassubek, Jan; Storch, Alexander; Ludolph, Albert C

2013-02-01

Clinical and neuroimaging data suggest impairment of the nigrostriatal system in amyotrophic lateral sclerosis (ALS). We thus hypothesized whether Parkinson's disease (PD)-like midbrain sonography findings are also present in ALS. Eighty-six patients with the diagnosis of possible or definite ALS according to revised El Escorial criteria were examined by transcranial B-mode sonography compared to 76 age- and gender-matched controls and 33 PD patients. Hyperechogenic areas of the midbrain representing the substantia nigra were measured planimetrically using standard protocols. In subjects with sufficient temporal acoustic bone windows, mean midbrain hyperechogenic areas were significantly higher in ALS (0.251 ± 0.104 cm(2)) and PD patients (0.286 ± 0.078 cm(2)) compared to controls (0.091 ± 0.054 cm(2)) with no significant difference between ALS and PD patients (one-way ANOVA: F value = 94.3; P diagnosis and differential diagnosis of PD and ALS alike.

Tualang Honey Protects the Rat Midbrain and Lung against Repeated Paraquat Exposure

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Suk Peng Tang

2017-01-01

Full Text Available Paraquat (PQ is a dopaminergic neurotoxin and a well-known pneumotoxicant that exerts its toxic effect via oxidative stress-mediated cellular injuries. This study investigated the protective effects of Tualang honey against PQ-induced toxicity in the midbrain and lungs of rats. The rats were orally treated with distilled water (2 mL/kg/day, Tualang honey (1.0 g/kg/day, or ubiquinol (0.2 g/kg/day throughout the experimental period. Two weeks after the respective treatments, the rats were injected intraperitoneally with saline (1 mL/kg/week or PQ (10 mg/kg/week once per week for four consecutive weeks. After four weekly exposures to PQ, the glutathione peroxidase activity and the number of tyrosine-hydroxylase immunopositive neurons in the midbrain were significantly decreased in animals from group PQ (p<0.05. The lungs of animals from group PQ showed significantly decreased activity of superoxide dismutase and glutathione-S-transferase. Treatment with Tualang honey ameliorated the toxic effects observed in the midbrain and lungs. The beneficial effects of Tualang honey were comparable to those of ubiquinol, which was used as a positive control. These findings suggest that treatment with Tualang honey may protect against PQ-induced toxicity in the rat midbrain and lung.

The Transcription Factor Orthodenticle Homeobox 2 Influences Axonal Projections and Vulnerability of Midbrain Dopaminergic Neurons

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Chung, Chee Yeun; Licznerski, Pawel; Alavian, Kambiz N.; Simeone, Antonio; Lin, Zhicheng; Martin, Eden; Vance, Jeffery; Isacson, Ole

2010-01-01

Two adjacent groups of midbrain dopaminergic neurons, A9 (substantia nigra pars compacta) and A10 (ventral tegmental area), have distinct projections and exhibit differential vulnerability in Parkinson's disease. Little is known about transcription factors that influence midbrain dopaminergic subgroup phenotypes or their potential role in disease.…

The Effect of Citalopram on Midbrain CRF Receptors 1 and 2 in a Primate Model of Stress-Induced Amenorrhea

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Senashova, Olga; Reddy, Arubala P.; Cameron, Judy L.; Bethea, Cynthia L.

2012-01-01

We have demonstrated marked differences in the neurobiology of the serotonin system between stress-sensitive (SS) and stress-resilient (SR) cynomolgus macaques characterized in a model of stress-induced amenorrhea, also called functional hypothalamic amenorrhea (FHA). Dysfunction of the serotonin system in SS monkeys suggested that administration of a selective serotonin reuptake inhibitor (SSRI) might correct FHA. This study examines the effect of escitalopram (CIT) administration to SS and SR monkeys on corticotrophin-releasing factor (CRF) receptor 1 (CRF-R1) and CRF receptor 2 (CRF-R2) gene expression in the serotonin cell body region of the midbrain dorsal raphe. CRF-R1 was not significantly different between groups. There was a significant effect of treatment and a significant interaction between treatment and stress sensitivity on the average CRF-R2-positive pixel area (P < .004 and P < .006, respectively) and on the average number of CRF-R2-positive cells (P < .023 and P < .025, respectively). CIT significantly increased CRF-R2-positive pixel area and cell number in the SS group (pixel area P < .001; cell number P < .01; Bonferoni) but not in the SR group. In summary, CIT administration tended to decrease CRF-R1, but the small animal number precluded significance. CIT administration significantly increased CRF-R2 only in SS animals. These data suggest that the administration of CIT reduces anxiogenic components and increases anxiolytic components of the CRF system in the midbrain serotonin network, which in turn leads to improved ovarian function. Moreover, these data raise the possibility that SSRIs may be effective in the treatment of stress-induced infertility. PMID:22412189

Early ultrastructural changes in the dorsal mucosa of rat tongue after irradiation, with special reference to the microvasculature

International Nuclear Information System (INIS)

Obinata, Ken-ichi; Ohshima, Hayato; Ito, Jusuke; Takano, Yoshiro.

1997-01-01

To clarify the acute effects of irradiation on the ultrastructural conformation of the dorsal mucosa of the rat tongue, with special reference to the changes in microvasculature. The proboscis of seventy rats were irradiated. The animals were then perfusion-fixed, followed by India ink-injection or resin casting at 3 to 7 days after irradiation. The bulk, frozen sections, or plastic embedded sections of the treated rat tongues were examined by light and electron microscopy. In the dorsal epithelium of the rat tongue, multi-nucleated cells appeared in the basal layer at 3 days after irradiation. At day 5, the thickness of the epithelial layer and connective tissue papillae decreased dramatically, concomitant with the shortening of the capillary loops. At day 7, lingual papillae and connective tissue papillae disappeared, leaving dissociated epithelial cells and numerous neutrophils migrating throughout the tissue. Subepithelial blood vessels displayed drastic dilation with a number of neutrophils adhering to the endothelial surface, but without ultrastructural abnormalities in its cellular components. Early changes in the dorsal mucosa of the irradiated rat tongue were limited to the basal epithelial cells, leading to a total disruption of the epithelial layer. Atrophic changes of the capillary loops is due to the loss of the connective tissue papillae. Dilation and conformational changes of the subepithelial capillaries appear to result from the inflammatory reaction, taking place secondarily to the loss of the epithelial barrier of the irradiated tongue. A difference in radiosensitivity among the epithelial, endothelial, and mesenchymal cell components of the rat tongue in vivo is suggested. (author)

Activation of Midbrain Structures by Associative Novelty and the Formation of Explicit Memory in Humans

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Schott, Bjorn H.; Sellner, Daniela B.; Lauer, Corinna-J.; Habib, Reza; Frey, Julietta U.; Guderian, Sebastian; Heinze, Hans-Jochen; Duzel, Emrah

2004-01-01

Recent evidence suggests a close functional relationship between memory formation in the hippocampus and dopaminergic neuromodulation originating in the ventral tegmental area and medial substantia nigra of the midbrain. Here we report midbrain activation in two functional MRI studies of visual memory in healthy young adults. In the first study,…

[Effects of perinatal exposure to bisphenol A inducing dopaminergic neuronal cell to apoptosis happening in midbrain of male rat offspring].

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Lin, Yong; Zhang, Hao; Wang, Wen-dong; Wu, De-sheng; Jiang, Song-hui; Qu, Wei-dong

2006-07-01

To investigate the mechanism and effect of rat perinatal exposure to bisphenol A (BPA) resulting in midbrain dopaminergic neuronal cell apoptosis and tyrosine hydroxylase expression of male offspring. Rat dams were randomLy divided into 4 groups on gestational day(GD) 10 and given orally the bisphenol A doses as 0, 0.5, 5, 50 mg/kg x d from GD10 to weaning. The brains of male offspring were obtained for detecting, with immunohistochemistry protocol, the Caspase-3, Bcl-2 and tyrosine hydroxylase expression in the midbrain on postnatal day 21 or 30 respectively, and the midbrain apoptotic neuronal cell were detected by TUNEL on PND21. The expression of Caspase-3 in the midbrain of rat male offspring were increased but bcl-2 were decreased on PND21 and 30, respectively. On PND21, apoptotic neuronal cell were found in the midbrain of high and medium doses groups. TH protein expression was decreased. Perinatal exposure to bisphenol A can induce the apoptosis of midbrain dopaminergic neuron in the male rat offspring even after weaning, and concomitantly decrease the midbrain TH immunoreactivity, this may cause the abnormal function of dopaminergic pathway of rat male offspring.

The human dorsal action control system develops in the absence of vision.

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Fiehler, Katja; Burke, Michael; Bien, Siegfried; Röder, Brigitte; Rösler, Frank

2009-01-01

The primate dorsal pathway has been proposed to compute vision for action. Although recent findings suggest that dorsal pathway structures contribute to somatosensory action control as well, it is yet not clear whether or not the development of dorsal pathway functions depends on early visual experience. Using functional magnetic resonance imaging, we investigated the pattern of cortical activation in congenitally blind and matched blindfolded sighted adults while performing kinesthetically guided hand movements. Congenitally blind adults activated similar dorsal pathway structures as sighted controls. Group-specific activations were found in the extrastriate cortex and the auditory cortex for congenitally blind humans and in the precuneus and the presupplementary motor area for sighted humans. Dorsal pathway activity was in addition observed for working memory maintenance of kinesthetic movement information in both groups. Thus, the results suggest that dorsal pathway functions develop in the absence of vision. This favors the idea of a general mechanism of movement control that operates regardless of the sensory input modality. Group differences in cortical activation patterns imply different movement control strategies as a function of visual experience.

The Effect of Short Moderate Stress on the Midbrain CRF System in a Macaque Model of Functional Hypothalamic Amenorrhea

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Bethea, Cynthia L; Phu, Kenny; Reddy, Arubala P; Cameron, Judy L

2014-01-01

Objective To study the effect of moderate stress on CRF components in the serotonergic midbrain region in a monkey model of FHA. Design After characterization of stress sensitivity, monkeys were moved to a novel room and given 20% less chow for 5 days prior to euthanasia. Setting University of Pittsburgh nonhuman primate facility. Animals Female cynomolgus macaques (Macaca fascicularis) characterized as highly stress resilient (HSR, n=5), medium stress resilient (MSR, N=4) or stress sensitive (SS, n=4). Intervention 5 days of diet in a novel room with unfamiliar conspecifics. Main Outcome Measures Density of CRF axons in the serotonergic dorsal raphe nucleus; the number of UCN1 cells; the density of UCN1 axons; the expression of CRF-R1 and CRF-R2 in the dorsal raphe nucleus. Results CRF innervation was higher in HSR than SS animals; UCN1 cell number was higher in HSR than SS animals and UCN1 axon bouton density was not different, all opposite of non-stressed animals. CRF-R1 was not different between the sensitivity groups, but CRF-R2 was higher in HSR than SS animals. The relative expression of CRF-R1 and R2 was similar to non-stressed animals. Conclusions HSR animals respond to stress with an increase in CRF delivery to serotonin neurons. With stress, UCN1 transport decreases in HSR animals. CRF receptor expression was similar with or without stress. These changes may contribute to resilience in HSR animals. PMID:23849846

Environmental enrichment increases transcriptional and epigenetic differentiation between mouse dorsal and ventral dentate gyrus.

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Zhang, Tie-Yuan; Keown, Christopher L; Wen, Xianglan; Li, Junhao; Vousden, Dulcie A; Anacker, Christoph; Bhattacharyya, Urvashi; Ryan, Richard; Diorio, Josie; O'Toole, Nicholas; Lerch, Jason P; Mukamel, Eran A; Meaney, Michael J

2018-01-19

Early life experience influences stress reactivity and mental health through effects on cognitive-emotional functions that are, in part, linked to gene expression in the dorsal and ventral hippocampus. The hippocampal dentate gyrus (DG) is a major site for experience-dependent plasticity associated with sustained transcriptional alterations, potentially mediated by epigenetic modifications. Here, we report comprehensive DNA methylome, hydroxymethylome and transcriptome data sets from mouse dorsal and ventral DG. We find genome-wide transcriptional and methylation differences between dorsal and ventral DG, including at key developmental transcriptional factors. Peripubertal environmental enrichment increases hippocampal volume and enhances dorsal DG-specific differences in gene expression. Enrichment also enhances dorsal-ventral differences in DNA methylation, including at binding sites of the transcription factor NeuroD1, a regulator of adult neurogenesis. These results indicate a dorsal-ventral asymmetry in transcription and methylation that parallels well-known functional and anatomical differences, and that may be enhanced by environmental enrichment.

Role of IL-1 beta and 5-HT2 receptors in midbrain periaqueductal gray (PAG) in potentiating defensive rage behavior in cat.

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Bhatt, Suresh; Bhatt, Rekha; Zalcman, Steven S; Siegel, Allan

2008-02-01

Feline defensive rage, a form of aggressive behavior that occurs in response to a threat can be elicited by electrical stimulation of the medial hypothalamus or midbrain periaqueductal gray (PAG). Our laboratory has recently begun a systematic examination of the role of cytokines in the regulation of rage and aggressive behavior. It was shown that the cytokine, interleukin-2 (IL-2), differentially modulates defensive rage when microinjected into the medial hypothalamus and PAG by acting through separate neurotransmitter systems. The present study sought to determine whether a similar relationship exists with respect to interleukin 1-beta (IL-1 beta), whose receptor activation in the medial hypothalamus potentiates defensive rage. Thus, the present study identified the effects of administration of IL-1 beta into the PAG upon defensive rage elicited from the medial hypothalamus. Microinjections of IL-1 beta into the dorsal PAG significantly facilitated defensive rage behavior elicited from the medial hypothalamus in a dose and time dependent manner. In addition, the facilitative effects of IL-1 beta were blocked by pre-treatment with anti-IL-1 beta receptor antibody, while IL-1 beta administration into the PAG had no effect upon predatory attack elicited from the lateral hypothalamus. The findings further demonstrated that IL-1 beta's effects were mediated through 5-HT(2) receptors since pretreatment with a 5-HT(2C) receptors antagonist blocked the facilitating effects of IL-1 beta. An extensive pattern of labeling of IL-1 beta and 5-HT(2C) receptors in the dorsal PAG supported these findings. The present study demonstrates that IL-beta in the dorsal PAG, similar to the medial hypothalamus, potentiates defensive rage behavior and is mediated through a 5-HT(2C) receptor mechanism.

The value of midbrain morphology in predicting prognosis in chronic disorders of consciousness: A preliminary ultrasound study.

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Chillura, Antonino; Naro, Antonino; Micchia, Katia; Bramanti, Alessia; Bramanti, Placido; Calabrò, Rocco Salvatore

2017-09-15

Transcranial sonography (TCS) of the brainstem is currently used to support the clinical diagnosis of movement disorders. The aim of the study was to assess the usefulness of midbrain TCS in assessing outcome in patients with Chronic Disorders of Consciousness (DOC). Eleven patients with Minimally Conscious State (MCS) and Unresponsive Wakefulness Syndrome (UWS) were included in the study. We measured the area and echogenicity of the midbrain by encoding and digitally analyzing the corresponding images from the orbitomeatal plane, the morphology of brain parenchyma from the thalamic and cella media plane, and the intracranial circulation. All the patients showed an increase of pulsatility index and numerous morphological alterations on all the scan planes. In particular, we found a loss of the characteristic butterfly-shape of the midbrain, which appeared hypoechoic in the UWS but not in the MCS patients. After six months, the patients were clinically assessed by using Glasgow Outcome Scale Extended (GOSE). We found that a higher increase in GOSE scoring at follow-up was correlated with larger area and higher echogenicity of the midbrain at baseline. The present study suggests that TCS data of the midbrain may support clinical assessment of patients with chronic DOC to estimate their outcome. Copyright © 2017 Elsevier B.V. All rights reserved.

Reward and aversion in a heterogeneous midbrain dopamine system.

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Lammel, Stephan; Lim, Byung Kook; Malenka, Robert C

2014-01-01

The ventral tegmental area (VTA) is a heterogeneous brain structure that serves a central role in motivation and reward processing. Abnormalities in the function of VTA dopamine (DA) neurons and the targets they influence are implicated in several prominent neuropsychiatric disorders including addiction and depression. Recent studies suggest that the midbrain DA system is composed of anatomically and functionally heterogeneous DA subpopulations with different axonal projections. These findings may explain a number of previously confusing observations that suggested a role for DA in processing both rewarding as well as aversive events. Here we will focus on recent advances in understanding the neural circuits mediating reward and aversion in the VTA and how stress as well as drugs of abuse, in particular cocaine, alter circuit function within a heterogeneous midbrain DA system. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dorsal periaqueductal gray stimulation facilitates anxiety-, but not panic-related, defensive responses in rats tested in the elevated T-maze

International Nuclear Information System (INIS)

Camplesi, M. Jr.; Bortoli, V.C. de; Paula Soares, V. de; Nogueira, R.L.; Zangrossi, H. Jr.

2012-01-01

The escape response to electrical or chemical stimulation of the dorsal periaqueductal gray matter (DPAG) has been associated with panic attacks. In order to explore the validity of the DPAG stimulation model for the study of panic disorder, we determined if the aversive consequences of the electrical or chemical stimulation of this midbrain area can be detected subsequently in the elevated T-maze. This animal model, derived from the elevated plus-maze, permits the measurement in the same rat of a generalized anxiety- and a panic-related defensive response, i.e., inhibitory avoidance and escape, respectively. Facilitation of inhibitory avoidance, suggesting an anxiogenic effect, was detected in male Wistar rats (200-220 g) tested in the elevated T-maze 30 min after DPAG electrical stimulation (current generated by a sine-wave stimulator, frequency at 60 Hz) or after local microinjection of the GABA A receptor antagonist bicuculline (5 pmol). Previous electrical (5, 15, 30 min, or 24 h before testing) or chemical stimulation of this midbrain area did not affect escape performance in the elevated T-maze or locomotion in an open-field. No change in the two behavioral tasks measured by the elevated T-maze was observed after repetitive (3 trials) electrical stimulation of the DPAG. The results indicate that activation of the DPAG caused a short-lived, but selective, increase in defensive behaviors associated with generalized anxiety

Dorsal periaqueductal gray stimulation facilitates anxiety-, but not panic-related, defensive responses in rats tested in the elevated T-maze

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Camplesi, M. Jr. [Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO (Brazil); Bortoli, V.C. de [Departamento de Ciências da Saúde, Centro Universitário Norte do Espírito Santo, Universidade Federal do Espírito Santo, São Mateus, ES (Brazil); Paula Soares, V. de [Departamento de Biofísica e Farmacologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil); Nogueira, R.L. [Laboratório de Psicologia Comparada, Universidade Estácio de Sá, Rio de Janeiro, RJ (Brazil); Zangrossi, H. Jr. [Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

2012-08-03

The escape response to electrical or chemical stimulation of the dorsal periaqueductal gray matter (DPAG) has been associated with panic attacks. In order to explore the validity of the DPAG stimulation model for the study of panic disorder, we determined if the aversive consequences of the electrical or chemical stimulation of this midbrain area can be detected subsequently in the elevated T-maze. This animal model, derived from the elevated plus-maze, permits the measurement in the same rat of a generalized anxiety- and a panic-related defensive response, i.e., inhibitory avoidance and escape, respectively. Facilitation of inhibitory avoidance, suggesting an anxiogenic effect, was detected in male Wistar rats (200-220 g) tested in the elevated T-maze 30 min after DPAG electrical stimulation (current generated by a sine-wave stimulator, frequency at 60 Hz) or after local microinjection of the GABA{sub A} receptor antagonist bicuculline (5 pmol). Previous electrical (5, 15, 30 min, or 24 h before testing) or chemical stimulation of this midbrain area did not affect escape performance in the elevated T-maze or locomotion in an open-field. No change in the two behavioral tasks measured by the elevated T-maze was observed after repetitive (3 trials) electrical stimulation of the DPAG. The results indicate that activation of the DPAG caused a short-lived, but selective, increase in defensive behaviors associated with generalized anxiety.

Anti-Apoptotic Protein Bcl-xL Expression in the Midbrain Raphe Region Is Sensitive to Stress and Glucocorticoids.

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Shishkina, Galina T; Kalinina, Tatyana S; Bulygina, Veta V; Lanshakov, Dmitry A; Babluk, Ekaterina V; Dygalo, Nikolay N

2015-01-01

Anti-apoptotic proteins are suggested to be important for the normal health of neurons and synapses as well as for resilience to stress. In order to determine whether stressful events may influence the expression of anti-apoptotic protein Bcl-xL in the midbrain and specifically in the midbrain serotonergic (5-HT) neurons involved in neurobehavioral responses to adverse stimuli, adult male rats were subjected to short-term or chronic forced swim stress. A short-term stress rapidly increased the midbrain bcl-xl mRNA levels and significantly elevated Bcl-xL immunoreactivity in the midbrain 5-HT cells. Stress-induced increase in glucocorticoid secretion was implicated in the observed effect. The levels of bcl-xl mRNA were decreased after stress when glucocorticoid elevation was inhibited by metyrapone (MET, 150 mg/kg), and this decrease was attenuated by glucocorticoid replacement with dexamethasone (DEX; 0.2 mg/kg). Both short-term stress and acute DEX administration, in parallel with Bcl-xL, caused a significant increase in tph2 mRNA levels and slightly enhanced tryptophan hydroxylase immunoreactivity in the midbrain. The increasing effect on the bcl-xl expression was specific to the short-term stress. Forced swim repeated daily for 2 weeks led to a decrease in bcl-xl mRNA in the midbrain without any effects on the Bcl-xL protein expression in the 5-HT neurons. In chronically stressed animals, an increase in tph2 gene expression was not associated with any changes in tryptophan hydroxylase protein levels. Our findings are the first to demonstrate that both short-term stress and acute glucocorticoid exposures induce Bcl-xL protein expression in the midbrain 5-HT neurons concomitantly with the activation of the 5-HT synthesis pathway in these neurons.

Anti-Apoptotic Protein Bcl-xL Expression in the Midbrain Raphe Region Is Sensitive to Stress and Glucocorticoids.

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Galina T Shishkina

Full Text Available Anti-apoptotic proteins are suggested to be important for the normal health of neurons and synapses as well as for resilience to stress. In order to determine whether stressful events may influence the expression of anti-apoptotic protein Bcl-xL in the midbrain and specifically in the midbrain serotonergic (5-HT neurons involved in neurobehavioral responses to adverse stimuli, adult male rats were subjected to short-term or chronic forced swim stress. A short-term stress rapidly increased the midbrain bcl-xl mRNA levels and significantly elevated Bcl-xL immunoreactivity in the midbrain 5-HT cells. Stress-induced increase in glucocorticoid secretion was implicated in the observed effect. The levels of bcl-xl mRNA were decreased after stress when glucocorticoid elevation was inhibited by metyrapone (MET, 150 mg/kg, and this decrease was attenuated by glucocorticoid replacement with dexamethasone (DEX; 0.2 mg/kg. Both short-term stress and acute DEX administration, in parallel with Bcl-xL, caused a significant increase in tph2 mRNA levels and slightly enhanced tryptophan hydroxylase immunoreactivity in the midbrain. The increasing effect on the bcl-xl expression was specific to the short-term stress. Forced swim repeated daily for 2 weeks led to a decrease in bcl-xl mRNA in the midbrain without any effects on the Bcl-xL protein expression in the 5-HT neurons. In chronically stressed animals, an increase in tph2 gene expression was not associated with any changes in tryptophan hydroxylase protein levels. Our findings are the first to demonstrate that both short-term stress and acute glucocorticoid exposures induce Bcl-xL protein expression in the midbrain 5-HT neurons concomitantly with the activation of the 5-HT synthesis pathway in these neurons.

Midbrain serotonin transporter binding potential measured with [11C]DASB is affected by serotonin transporter genotype

International Nuclear Information System (INIS)

Reimold, M.; Bares, R.; Reischl, G.; Solbach, C.; Machulla, H.-J.; Smolka, M.N.; Mann, K.; Schumann, G.; Zimmer, A.; Wrase, J.; Hu, X.-Z.; Goldman, D.; Heinz, A.

2007-01-01

Homozygote carriers of two long (L) alleles of the serotonin transporter (5-HTT) regulatory region displayed in vitro a twofold increase in 5-HTT expression compared with carriers of one or two short (S) alleles. However, in vivo imaging studies yielded contradictory results. Recently, an A > G exchange leading to differential transcriptional activation of 5-HTT mRNA in lymphobalstoid cell lines was discovered in the 5-HTT regulatory region. In vitro and in vivo evidence suggests that [ 11 C]DASB, a new 5-HTT ligand offers some advantages over the ligands used in previous studies in measuring 5-HTT density independent of synaptic levels of serotonin. We assessed 5-HTT binding potential (BP 2) in the midbrain of 19 healthy subjects with positron emission tomography and [ 11 C]DASB. Accounting for the hypothesized functional similarity of L G and S in driving 5-HTT transcription, we assessed whether L A L A homozygotes display increased midbrain BP 2 compared with carriers of at least one S allele. BP 2 in the midbrain was significantly increased in L A L A homozygotes compared with carriers of at least one S allele. Interestingly, the genotype effect on the midbrain was significantly different from that on the thalamus and the amygdala where no group differences were detected. This in vivo study provides further evidence that subjects homozygous for the L A allele display increased expression of 5-HTT in the midbrain, the origin of central serotonergic projections. (author)

Genetic deletion of afadin causes hydrocephalus by destruction of adherens junctions in radial glial and ependymal cells in the midbrain.

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Hideaki Yamamoto

Full Text Available Adherens junctions (AJs play a role in mechanically connecting adjacent cells to maintain tissue structure, particularly in epithelial cells. The major cell-cell adhesion molecules at AJs are cadherins and nectins. Afadin binds to both nectins and α-catenin and recruits the cadherin-β-catenin complex to the nectin-based cell-cell adhesion site to form AJs. To explore the role of afadin in radial glial and ependymal cells in the brain, we generated mice carrying a nestin-Cre-mediated conditional knockout (cKO of the afadin gene. Newborn afadin-cKO mice developed hydrocephalus and died neonatally. The afadin-cKO brain displayed enlarged lateral ventricles and cerebral aqueduct, resulting from stenosis of the caudal end of the cerebral aqueduct and obliteration of the ventral part of the third ventricle. Afadin deficiency further caused the loss of ependymal cells from the ventricular and aqueductal surfaces. During development, radial glial cells, which terminally differentiate into ependymal cells, scattered from the ventricular zone and were replaced by neurons that eventually covered the ventricular and aqueductal surfaces of the afadin-cKO midbrain. Moreover, the denuded ependymal cells were only occasionally observed in the third ventricle and the cerebral aqueduct of the afadin-cKO midbrain. Afadin was co-localized with nectin-1 and N-cadherin at AJs of radial glial and ependymal cells in the control midbrain, but these proteins were not concentrated at AJs in the afadin-cKO midbrain. Thus, the defects in the afadin-cKO midbrain most likely resulted from the destruction of AJs, because AJs in the midbrain were already established before afadin was genetically deleted. These results indicate that afadin is essential for the maintenance of AJs in radial glial and ependymal cells in the midbrain and is required for normal morphogenesis of the cerebral aqueduct and ventral third ventricle in the midbrain.

Fos expression in the midbrain periaqueductal grey after trigeminovascular stimulation

NARCIS (Netherlands)

Hoskin, KL; Bulmer, DCE; Lasalandra, M; Jonkman, A; Goadsby, PJ

There is an accumulating body of evidence suggesting that the periaqueductal grey (PAG) is involved in the pathophysiology of migraine. Positron emission tomography (PET) studies in humans have shown that the caudal ventrolateral midbrain, encompassing the ventrolateral PAG, has activations during

Lumbar dorsal ramus syndrome.

Science.gov (United States)

Bogduk, N

1980-11-15

Low back pain, referred pain in the lower limbs, and spasm of the back, gluteal, and hamstring muscles are clinical features which can be induced in normal volunteers by stimulating structures which are innervated by the lumbar dorsal rami. Conversely, they can be relieved in certain patients by selective interruption of conduction along dorsal rami. These facts permit the definition of a lumbar dorsal ramus syndrome, which can be distinguished from the intervertebral disc syndrome and other forms of low back pain. The distinguishing feature is that, in lumbar dorsal ramus syndrome, all the clinical features are exclusively mediated by dorsal rami and do not arise from nerve-root compression. The pathophysiology, pathology, and treatment of this syndrome are described. Recognition of this syndrome, and its treatment with relatively minor procedures, can obviate the need for major surgery which might otherwise be undertaken.

DORSAL ROOT REGENERATION INTO TRANSPLANTS OF DORSAL OR VENTRAL HALF OF EMBRYONIC SPINAL CORD

OpenAIRE

Ohta, Tohru; Itoh, Yasunobu; Tessler, Alan; Mizoi, Kazuo

2009-01-01

Adult cut dorsal root axons regenerate into the transplants of embryonic spinal cord (ESC) and form functional synapses within the transplants. It is unknown whether the growth is specific to transplants of dorsal half of ESC, a normal target of most dorsal root axons, or whether it is due to properties shared by transplants of ventral half of ESC. We used calcitonin gene-related peptide (CGRP) immunohistochemistry to label to the subpopulations of regenerated adult dorsal root axons, quantit...

The effect of short moderate stress on the midbrain corticotropin-releasing factor system in a macaque model of functional hypothalamic amenorrhea.

Science.gov (United States)

Bethea, Cynthia L; Phu, Kenny; Reddy, Arubala P; Cameron, Judy L

2013-10-01

To study the effect of moderate stress on corticotropin-releasing factor (CRF) components in the serotonergic midbrain region in a monkey model of functional hypothalamic amenorrhea. After characterization of stress sensitivity, monkeys were moved to a novel room and given 20% less chow for 5 days before euthanasia. Primate research center. Female cynomolgus macaques (Macaca fascicularis) characterized as highly stress resilient (HSR, n = 5), medium stress resilient (n = 4), or stress sensitive (SS, n = 4). Five days of diet in a novel room with unfamiliar conspecifics. Density of CRF axons in the serotonergic dorsal raphe nucleus; the number of urocortin 1 (UCN1) cells; the density of UCN1 axons; the expression of CRF receptor 1 (CRF-R1) and CRF-R2 in the dorsal raphe nucleus. The CRF innervation was higher in HSR than in SS animals; UCN1 cell number was higher in HSR than in SS animals and UCN1 axon bouton density was not different; all opposite of nonstressed animals. The CRF-R1 was not different between the sensitivity groups, but CRF-R2 was higher in HSR than in SS animals. The relative expression of CRF-R1 and CRF-R2 was similar to nonstressed animals. The HSR animals respond to stress with an increase in CRF delivery to serotonin neurons. With stress, UCN1 transport decreases in HSR animals. The CRF receptor expression was similar with or without stress. These changes may contribute to resilience in HSR animals. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Apc1 is required for maintenance of local brain organizers and dorsal midbrain survival.

NARCIS (Netherlands)

Paridaen, J.T.M.; Danesin, C.; Elas, A.T.; van de Water, S.G.P.; Houart, C.; Zivkovic, D.

2009-01-01

The tumor suppressor Apc1 is an intracellular antagonist of the Wnt/beta-catenin pathway, which is vital for induction and patterning of the early vertebrate brain. However, its role in later brain development is less clear. Here, we examined the mechanisms underlying effects of an Apc1

Expression of immediate-early genes in the dorsal cochlear nucleus in salicylate-induced tinnitus.

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Hu, Shou-Sen; Mei, Ling; Chen, Jian-Yong; Huang, Zhi-Wu; Wu, Hao

2016-02-01

Spontaneous neuronal activity in dorsal cochlear nucleus (DCN) may be involved in the physiological processes underlying salicylate-induced tinnitus. As a neuronal activity marker, immediate-early gene (IEG) expression, especially activity-dependent cytoskeletal protein (Arc/Arg3.1) and the early growth response gene-1 (Egr-1), appears to be highly correlated with sensory-evoked neuronal activity. However, their relationships with tinnitus induced by salicylate have rarely been reported in the DCN. In this study, we assessed the effect of acute and chronic salicylate treatment on the expression of N-methyl D-aspartate receptor subunit 2B (NR2B), Arg3.1, and Egr-1. We also observed ultrastructural alterations in the DCN synapses in an animal model of tinnitus. Levels of mRNA and protein expression of NR2B and Arg3.1 were increased in rats that were chronically administered salicylate (200 mg/kg, twice daily for 3, 7, or 14 days). These levels returned to baseline 14 days after cessation of treatment. However, no significant changes were observed in Egr-1 gene expression in any groups. Furthermore, rats subjected to long-term salicylate administration showed more presynaptic vesicles, thicker and longer postsynaptic densities, and increased synaptic interface curvature. Alterations of Arg3.1 and NR2B may be responsible for the changes in the synaptic ultrastructure. These changes confirm that salicylate can cause neural plasticity changes at the DCN level.

Response characteristics of vibration-sensitive neurons in the midbrain of the grassfrog, Rana temporaria

DEFF Research Database (Denmark)

Christensen-Dalsgaard, J; Jørgensen, M B

1989-01-01

European grassfrogs (Rana temporaria) were stimulated with pulsed sinusoidal, vertical vibrations (10-300 Hz) and the responses of 46 single midbrain neurons were recorded in awake, immobilized animals. Most units (40) had simple V-shaped excitatory vibrational tuning curves. The distribution of ...... stimuli probably play a role in communication and detection of predators and the vibration-sensitive midbrain neurons may be involved in the central processing of such behaviorally significant stimuli.......European grassfrogs (Rana temporaria) were stimulated with pulsed sinusoidal, vertical vibrations (10-300 Hz) and the responses of 46 single midbrain neurons were recorded in awake, immobilized animals. Most units (40) had simple V-shaped excitatory vibrational tuning curves. The distribution...... of best frequencies (BF's) was bimodal with peaks at 10 and 100 Hz and the thresholds ranged from 0.02 to 1.28 cm/s2 at the BF. Twenty-three neurons showed phasic-tonic and 11 neurons phasic responses. The dynamic range of seismic intensity for most neurons was 20-30 dB. In contrast to the sharp phase...

Development and function of the midbrain dopamine system: what we know and what we need to.

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Bissonette, G B; Roesch, M R

2016-01-01

The past two decades have seen an explosion in our understanding of the origin and development of the midbrain dopamine system. Much of this work has been focused on the aspects of dopamine neuron development related to the onset of movement disorders such as Parkinson's disease, with the intent of hopefully delaying, preventing or fixing symptoms. While midbrain dopamine degeneration is a major focus for treatment and research, many other human disorders are impacted by abnormal dopamine, including drug addiction, autism and schizophrenia. Understanding dopamine neuron ontogeny and how dopamine connections and circuitry develops may provide us with key insights into potentially important avenues of research for other dopamine-related disorders. This review will provide a brief overview of the major molecular and genetic players throughout the development of midbrain dopamine neurons and what we know about the behavioral- and disease-related implications associated with perturbations to midbrain dopamine neuron development. We intend to combine the knowledge of two broad fields of neuroscience, both developmental and behavioral, with the intent on fostering greater discussion between branches of neuroscience in the service of addressing complex cognitive questions from a developmental perspective and identifying important gaps in our knowledge for future study. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Activation of midbrain structures by associative novelty and the formation of explicit memory in humans.

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Schott, Björn H; Sellner, Daniela B; Lauer, Corinna-J; Habib, Reza; Frey, Julietta U; Guderian, Sebastian; Heinze, Hans-Jochen; Düzel, Emrah

2004-01-01

Recent evidence suggests a close functional relationship between memory formation in the hippocampus and dopaminergic neuromodulation originating in the ventral tegmental area and medial substantia nigra of the midbrain. Here we report midbrain activation in two functional MRI studies of visual memory in healthy young adults. In the first study, participants distinguished between familiar and novel configurations of pairs of items which had been studied together by either learning the location or the identity of the items. In the second study, participants studied words by either rating the words' pleasantness or counting syllables. The ventral tegmental area and medial substantia nigra showed increased activation by associative novelty (first study) and subsequent free recall performance (second study). In both studies, this activation accompanied hippocampal activation, but was unaffected by the study task. Thus midbrain regions seem to participate selectively in hippocampus-dependent processes of associative novelty and explicit memory formation, but appear to be unaffected by other task-relevant aspects.

Do dorsal raphe 5-HT neurons encode "beneficialness"?

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Luo, Minmin; Li, Yi; Zhong, Weixin

2016-11-01

The neurotransmitter serotonin (5-hydroxytryptamine; 5-HT) affects numerous behavioral and physiological processes. Drugs that alter 5-HT signaling treat several major psychiatric disorders and may lead to widespread abuse. The dorsal raphe nucleus (DRN) in the midbrain provides a majority of 5-HT for the forebrain. The importance of 5-HT signaling propels the search for a general theoretical framework under which the diverse functions of the DRN 5-HT neurons can be interpreted and additional therapeutic solutions may be developed. However, experimental data so far support several seeming irreconcilable theories, suggesting that 5-HT neurons mediate behavioral inhibition, aversive processing, or reward signaling. Here, we review recent progresses and propose that DRN 5-HT neurons encode "beneficialness" - how beneficial the current environmental context represents for an individual. Specifically, we speculate that the activity of these neurons reflects the possible net benefit of the current context as determined by p·R-C, in which p indicates reward probability, R the reward value, and C the cost. Through the widespread projections of these neurons to the forebrain, the beneficialness signal may reconfigure neural circuits to bias perception, boost positive emotions, and switch behavioral choices. The "beneficialness" hypothesis can explain many conflicting observations, and at the same time raises new questions. We suggest additional experiments that will help elucidate the exact computational functions of the DRN 5-HT neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

Cooperative transcription activation by Nurr1 and Pitx3 induces embryonic stem cell maturation to the midbrain dopamine neuron phenotype

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Martinat, Cecile; Bacci, Jean-Jacques; Leete, Thomas

2006-01-01

's disease. We sought to identify genes that can potentiate maturation of ES cell cultures to the midbrain DA neuron phenotype. A number of transcription factors have been implicated in the development of midbrain DA neurons by expression analyses and loss-of-function knockout mouse studies, including Nurr1......Midbrain dopamine (DA) neurons play a central role in the regulation of voluntary movement, and their degeneration is associated with Parkinson's disease. Cell replacement therapies, and in particular embryonic stem (ES) cell-derived DA neurons, offer a potential therapeutic venue for Parkinson......, Pitx3, Lmx1b, Engrailed-1, and Engrailed-2. However, none of these factors appear sufficient alone to induce the mature midbrain DA neuron phenotype in ES cell cultures in vitro, suggesting a more complex regulatory network. Here we show that Nurr1 and Pitx3 cooperatively promote terminal maturation...

Dorsal skinfold chamber models in mice

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Schreiter, Jeannine

2017-07-01

Full Text Available Background/purpose: The use of dorsal skinfold chamber models has substantially improved the understanding of micro-vascularisation in pathophysiology over the last eight decades. It allows pathophysiological studies of vascularisation over a continuous period of time. The dorsal skinfold chamber is an attractive technique for monitoring the vascularisation of autologous or allogenic transplants, wound healing, tumorigenesis and compatibility of biomaterial implants. To further reduce the animals’ discomfort while carrying the dorsal skinfold chamber, we developed a smaller chamber (the Leipzig Dorsal Skinfold Chamber and summarized the commercial available chamber models. In addition we compared our model to the common chamber. Methods: The Leipzig Dorsal Skinfold Chamber was applied to female mice with a mean weight of 22 g. Angiogenesis within the dorsal skinfold chamber was evaluated after injection of fluorescein isothiocyanate dextran with an Axio Scope microscope. The mean vessel density within the dorsal skinfold chamber was assessed over a period of 21 days at five different time points. The gained data were compared to previous results using a bigger and heavier dorsal skinfold model in mice. A PubMed and a patent search were performed and all papers related to “dorsal skinfold chamber” from 1 of January 2006 to 31 of December 2015 were evaluated regarding the dorsal skinfold chamber models and their technical improvements. The main models are described and compared to our titanium Leipzig Dorsal Skinfold Chamber model.Results: The Leipzig Dorsal Skinfold Chamber fulfils all requirements of continuous models known from previous chamber models while reducing irritation to the mice. Five different chamber models have been identified showing substantial regional diversity. The newly elaborated titanium dorsal skinfold chamber may replace the pre-existing titanium chamber model used in Germany so far, as it is smaller and lighter

How does early maternal separation and chronic stress in adult rats affect the immunoreactivity of serotonergic neurons within the dorsal raphe nucleus?

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Pollano, Antonella; Trujillo, Verónica; Suárez, Marta M

2018-01-01

Vulnerability to emotional disorders like depression derives from interactions between early and late environments, including stressful conditions. The serotonin (5HT) system is strongly affected by stress and chronic unpredictable stress can alter the 5HT system. We evaluated the distribution of active serotonergic neurons in the dorsal raphe nucleus (DR) through immunohistochemistry in maternally separated and chronically stressed rats treated with an antidepressant, tianeptine, whose mechanism of action is still under review. Male Wistar rats were subjected to daily maternal separation (MS) for 4.5 h between postnatal days (PND) 1-21, or to animal facility rearing (AFR). Between (PND) days 50-74, rats were exposed to chronic unpredictable stress and were treated daily with tianeptine (10 mg/kg) or vehicle. We found an interaction between the effects of MS and chronic unpredictable stress on Fos-5HT immunoreactive cells at mid-caudal level of the DR. MS-chronically stressed rats showed an increase of Fos-5HT immunoreactive cells compared with AFR-chronically stressed rats. The ventrolateral (DRL/VLPAG) and dorsal (DRD) subdivisions of the DR were significantly more active than the ventral part (DRV). At the rostral level of the DR, tianeptine decreased the number of Fos-5HT cells in DR in the AFR groups, both unstressed and stressed. Overall, our results support the idea of a match in phenotype exhibited when the early and the adult environment correspond.

Development and function of the midbrain dopamine system: what we know and what we need to

OpenAIRE

Bissonette, G. B.; Roesch, M. R.

2015-01-01

The past two decades have seen an explosion in our understanding of the origin and development of the midbrain dopamine system. Much of this work has been focused on the aspects of dopamine neuron development related to the onset of movement disorders such as Parkinson’s disease, with the intent of hopefully delaying, preventing or fixing symptoms. While midbrain dopamine degeneration is a major focus for treatment and research, many other human disorders are impacted by abnormal dopamine, in...

An Lmx1b-miR135a2 regulatory circuit modulates Wnt1/Wnt signaling and determines the size of the midbrain dopaminergic progenitor pool.

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Angela Anderegg

Full Text Available MicroRNAs regulate gene expression in diverse physiological scenarios. Their role in the control of morphogen related signaling pathways has been less studied, particularly in the context of embryonic Central Nervous System (CNS development. Here, we uncover a role for microRNAs in limiting the spatiotemporal range of morphogen expression and function. Wnt1 is a key morphogen in the embryonic midbrain, and directs proliferation, survival, patterning and neurogenesis. We reveal an autoregulatory negative feedback loop between the transcription factor Lmx1b and a newly characterized microRNA, miR135a2, which modulates the extent of Wnt1/Wnt signaling and the size of the dopamine progenitor domain. Conditional gain of function studies reveal that Lmx1b promotes Wnt1/Wnt signaling, and thereby increases midbrain size and dopamine progenitor allocation. Conditional removal of Lmx1b has the opposite effect, in that expansion of the dopamine progenitor domain is severely compromised. Next, we provide evidence that microRNAs are involved in restricting dopamine progenitor allocation. Conditional loss of Dicer1 in embryonic stem cells (ESCs results in expanded Lmx1a/b+ progenitors. In contrast, forced elevation of miR135a2 during an early window in vivo phenocopies the Lmx1b conditional knockout. When En1::Cre, but not Shh::Cre or Nes::Cre, is used for recombination, the expansion of Lmx1a/b+ progenitors is selectively reduced. Bioinformatics and luciferase assay data suggests that miR135a2 targets Lmx1b and many genes in the Wnt signaling pathway, including Ccnd1, Gsk3b, and Tcf7l2. Consistent with this, we demonstrate that this mutant displays reductions in the size of the Lmx1b/Wnt1 domain and range of canonical Wnt signaling. We posit that microRNA modulation of the Lmx1b/Wnt axis in the early midbrain/isthmus could determine midbrain size and allocation of dopamine progenitors. Since canonical Wnt activity has recently been recognized as a key

Response to the Dorsal Anterior Gradient of EGFR Signaling in Drosophila Oogenesis Is Prepatterned by Earlier Posterior EGFR Activation

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Mariana Fregoso Lomas

2013-08-01

Full Text Available Spatially restricted epidermal growth factor receptor (EGFR activity plays a central role in patterning the follicular epithelium of the Drosophila ovary. In midoogenesis, localized EGFR activation is achieved by the graded dorsal anterior localization of its ligand, Gurken. Graded EGFR activity determines multiple dorsal anterior fates along the dorsal-ventral axis but cannot explain the sharp posterior limit of this domain. Here, we show that posterior follicle cells express the T-box transcription factors Midline and H15, which render cells unable to adopt a dorsal anterior fate in response to EGFR activation. The posterior expression of Midline and H15 is itself induced in early oogenesis by posteriorly localized EGFR signaling, defining a feedback loop in which early induction of Mid and H15 confers a molecular memory that fundamentally alters the outcome of later EGFR signaling. Spatial regulation of the EGFR pathway thus occurs both through localization of the ligand and through localized regulation of the cellular response.

Hierarchical prediction errors in midbrain and basal forebrain during sensory learning.

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Iglesias, Sandra; Mathys, Christoph; Brodersen, Kay H; Kasper, Lars; Piccirelli, Marco; den Ouden, Hanneke E M; Stephan, Klaas E

2013-10-16

In Bayesian brain theories, hierarchically related prediction errors (PEs) play a central role for predicting sensory inputs and inferring their underlying causes, e.g., the probabilistic structure of the environment and its volatility. Notably, PEs at different hierarchical levels may be encoded by different neuromodulatory transmitters. Here, we tested this possibility in computational fMRI studies of audio-visual learning. Using a hierarchical Bayesian model, we found that low-level PEs about visual stimulus outcome were reflected by widespread activity in visual and supramodal areas but also in the midbrain. In contrast, high-level PEs about stimulus probabilities were encoded by the basal forebrain. These findings were replicated in two groups of healthy volunteers. While our fMRI measures do not reveal the exact neuron types activated in midbrain and basal forebrain, they suggest a dichotomy between neuromodulatory systems, linking dopamine to low-level PEs about stimulus outcome and acetylcholine to more abstract PEs about stimulus probabilities. Copyright © 2013 Elsevier Inc. All rights reserved.

Isolated Medial Rectus Nuclear Palsy as a Rare Presentation of Midbrain Infarction.

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Al-Sofiani, Mohammed; Lee Kwen, Peterkin

2015-10-08

Diplopia is a common subjective complaint that can be the first manifestation of a serious pathology. Here, we report a rare case of midbrain infarction involving the lateral subnucleus of the oculomotor nuclear complex presenting as diplopia, with no other stroke manifestations. An 83-year-old right-handed white man with past medical history of diabetes mellitus, hypertension, dyslipidemia, and coronary artery disease presented to the emergency department (ED) with diplopia and unsteadiness. Two days prior to admission, the patient woke up with constant horizontal diplopia and unsteadiness, which limited his daily activities and led to a fall at home. He denied any weakness, clumsiness, nausea, vomiting, photophobia, fever, or chills. Ocular exam showed a disconjugate gaze at rest, weakness of the left medial rectus muscle, impaired convergence test, and bilateral 3-mm reactive pupils. The diplopia resolved by closing either eye. The remaining extraocular muscles and other cranial nerves were normal. There was no nystagmus, ptosis, or visual field deficit. Sensation, muscle tone, and strength were normal in all extremities. Magnetic resonance imaging (MRI) of the brain revealed a tiny focus of restricted diffusion in the left posterior lateral midbrain. A thorough history and physical examination is essential to diagnose and manage diplopia. Isolated extraocular palsy is usually thought to be caused by orbital lesions or muscular diseases. Here, we report a case of midbrain infarction manifested as isolated medial rectus palsy.

A Comparative Study of Dorsal Buccal Mucosa Graft Substitution Urethroplasty by Dorsal Urethrotomy Approach versus Ventral Sagittal Urethrotomy Approach

OpenAIRE

Pahwa, Mrinal; Gupta, Sanjeev; Pahwa, Mayank; Jain, Brig D. K.; Gupta, Manu

2013-01-01

Objectives. To compare the outcome of dorsal buccal mucosal graft (BMG) substitution urethroplasty by dorsal urethrotomy approach with ventral urethrotomy approach in management of stricture urethra. Methods and Materials. A total of 40 patients who underwent dorsal BMG substitution urethroplasty were randomized into two groups. 20 patients underwent dorsal onlay BMG urethroplasty as described by Barbagli, and the other 20 patients underwent dorsal BMG urethroplasty by ventral urethrotomy as ...

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

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Sicong eTu

2014-09-01

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

The functional anatomy of speech perception: Dorsal and ventral processing pathways

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Hickok, Gregory

2003-04-01

Drawing on recent developments in the cortical organization of vision, and on data from a variety of sources, Hickok and Poeppel (2000) have proposed a new model of the functional anatomy of speech perception. The model posits that early cortical stages of speech perception involve auditory fields in the superior temporal gyrus bilaterally (although asymmetrically). This cortical processing system then diverges into two broad processing streams, a ventral stream, involved in mapping sound onto meaning, and a dorsal stream, involved in mapping sound onto articulatory-based representations. The ventral stream projects ventrolaterally toward inferior posterior temporal cortex which serves as an interface between sound and meaning. The dorsal stream projects dorsoposteriorly toward the parietal lobe and ultimately to frontal regions. This network provides a mechanism for the development and maintenance of ``parity'' between auditory and motor representations of speech. Although the dorsal stream represents a tight connection between speech perception and speech production, it is not a critical component of the speech perception process under ecologically natural listening conditions. Some degree of bi-directionality in both the dorsal and ventral pathways is also proposed. A variety of recent empirical tests of this model have provided further support for the proposal.

Versatility of the ventral approach in bulbar urethroplasty using dorsal, ventral or dorsal plus ventral oral grafts.

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Palminteri, Enzo; Berdondini, Elisa; Fusco, Ferdinando; De Nunzio, Cosimo; Giannitsas, Kostas; Shokeir, Ahmed A

2012-06-01

To investigate the versatility of the ventral urethrotomy approach in bulbar reconstruction with buccal mucosa (BM) grafts placed on the dorsal, ventral or dorsal plus ventral urethral surface. Between 1999 and 2008, 216 patients with bulbar strictures underwent BM graft urethroplasty using the ventral-sagittal urethrotomy approach. Of these patients, 32 (14.8%; mean stricture 3.2 cm, range 1.5-5) had a dorsal graft urethroplasty (DGU), 121 (56%; mean stricture 3.7, range 1.5-8) a ventral graft urethroplasty (VGU), and 63 (29.2%; mean stricture 3.4, range 1.5-10) a dorsal plus ventral graft urethroplasty (DVGU). The strictured urethra was opened by a ventral-sagittal urethrotomy and BM graft was inserted dorsally or ventrally or dorsal plus ventral to augment the urethral plate. The median follow-up was 37 months. The overall 5-year actuarial success rate was 91.4%. The 5-year actuarial success rates were 87.8%, 95.5% and 86.3% for the DGU, VGU and DVGU, respectively. There were no statistically significant differences among the three groups. Success rates decreased significantly only with a stricture length of >4 cm. In BM graft bulbar urethroplasties the ventral urethrotomy access is simple and versatile, allowing an intraoperative choice of dorsal, ventral or combined dorsal and ventral grafting, with comparable success rates.

A Neural Correlate of Predicted and Actual Reward-Value Information in Monkey Pedunculopontine Tegmental and Dorsal Raphe Nucleus during Saccade Tasks

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Okada, Ken-ichi; Nakamura, Kae; Kobayashi, Yasushi

2011-01-01

Dopamine, acetylcholine, and serotonin, the main modulators of the central nervous system, have been proposed to play important roles in the execution of movement, control of several forms of attentional behavior, and reinforcement learning. While the response pattern of midbrain dopaminergic neurons and its specific role in reinforcement learning have been revealed, the role of the other neuromodulators remains rather elusive. Here, we review our recent studies using extracellular recording from neurons in the pedunculopontine tegmental nucleus, where many cholinergic neurons exist, and the dorsal raphe nucleus, where many serotonergic neurons exist, while monkeys performed eye movement tasks to obtain different reward values. The firing patterns of these neurons are often tonic throughout the task period, while dopaminergic neurons exhibited a phasic activity pattern to the task event. The different modulation patterns, together with the activity of dopaminergic neurons, reveal dynamic information processing between these different neuromodulator systems. PMID:22013541

Attention supports verbal short-term memory via competition between dorsal and ventral attention networks.

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Majerus, Steve; Attout, Lucie; D'Argembeau, Arnaud; Degueldre, Christian; Fias, Wim; Maquet, Pierre; Martinez Perez, Trecy; Stawarczyk, David; Salmon, Eric; Van der Linden, Martial; Phillips, Christophe; Balteau, Evelyne

2012-05-01

Interactions between the neural correlates of short-term memory (STM) and attention have been actively studied in the visual STM domain but much less in the verbal STM domain. Here we show that the same attention mechanisms that have been shown to shape the neural networks of visual STM also shape those of verbal STM. Based on previous research in visual STM, we contrasted the involvement of a dorsal attention network centered on the intraparietal sulcus supporting task-related attention and a ventral attention network centered on the temporoparietal junction supporting stimulus-related attention. We observed that, with increasing STM load, the dorsal attention network was activated while the ventral attention network was deactivated, especially during early maintenance. Importantly, activation in the ventral attention network increased in response to task-irrelevant stimuli briefly presented during the maintenance phase of the STM trials but only during low-load STM conditions, which were associated with the lowest levels of activity in the dorsal attention network during encoding and early maintenance. By demonstrating a trade-off between task-related and stimulus-related attention networks during verbal STM, this study highlights the dynamics of attentional processes involved in verbal STM.

Differences in Number of Midbrain Dopamine Neurons Associated with Summer and Winter Photoperiods in Humans.

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Tim D Aumann

Full Text Available Recent evidence indicates the number of dopaminergic neurons in the adult rodent hypothalamus and midbrain is regulated by environmental cues, including photoperiod, and that this occurs via up- or down-regulation of expression of genes and proteins that are important for dopamine (DA synthesis in extant neurons ('DA neurotransmitter switching'. If the same occurs in humans, it may have implications for neurological symptoms associated with DA imbalances. Here we tested whether there are differences in the number of tyrosine hydroxylase (TH, the rate-limiting enzyme in DA synthesis and DA transporter (DAT immunoreactive neurons in the midbrain of people who died in summer (long-day photoperiod, n = 5 versus winter (short-day photoperiod, n = 5. TH and DAT immunoreactivity in neurons and their processes was qualitatively higher in summer compared with winter. The density of TH immunopositive (TH+ neurons was significantly (~6-fold higher whereas the density of TH immunonegative (TH- neurons was significantly (~2.5-fold lower in summer compared with winter. The density of total neurons (TH+ and TH- combined was not different. The density of DAT+ neurons was ~2-fold higher whereas the density of DAT- neurons was ~2-fold lower in summer compared with winter, although these differences were not statistically significant. In contrast, midbrain nuclear volume, the density of supposed glia (small TH- cells, and the amount of TUNEL staining were the same in summer compared with winter. This study provides the first evidence of an association between environmental stimuli (photoperiod and the number of midbrain DA neurons in humans, and suggests DA neurotransmitter switching underlies this association.

Radiographic Outcomes of Dorsal Distraction Distal Radius Plating for Fractures With Dorsal Marginal Impaction.

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Huish, Eric G; Coury, John G; Ibrahim, Mohamed A; Trzeciak, Marc A

2017-04-01

The purpose of this study is to compare radiographic outcomes of patients treated with dorsal spanning plates with previously reported normal values of radiographic distal radius anatomy and compare the results with prior publications for both external fixation and internal fixation with volar locked plates. Patients with complex distal radius fractures including dorsal marginal impaction pattern necessitating dorsal distraction plating at the discretion of the senior authors (M.A.T. and M.A.I.) from May 30, 2013, to December 29, 2015, were identified and included in the study. Retrospective chart and radiograph review was performed on 19 patients, 11 male and 8 female, with mean age of 47.83 years (22-82). No patients were excluded from the study. All fractures united prior to plate removal. The average time the plate was in place was 80.5 days (49-129). Follow-up radiographs showed average radial inclination of 20.5° (13.2°-25.5°), radial height of 10.7 mm (7.5-14 mm), ulnar variance of -0.3 mm (-2.1 to 3.1 mm), and volar tilt of 7.9° (-3° to 15°). One patient had intra-articular step-off greater than 2 mm. Dorsal distraction plating of complex distal radius fractures yields good radiographic results with minimal complications. In cases of complex distal radius fractures including dorsal marginal impaction where volar plating is not considered adequate, a dorsal distraction plate should be considered as an alternative to external fixation due to reduced risk for infection and better control of volar tilt.

Elevated midbrain serotonin transporter availability in mixed mania: a case report

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Kuikka Jyrki

2004-09-01

Full Text Available Abstract Background Results obtained from brain imaging studies indicate that serotonin transporter (SERT and dopamine transporter (DAT densities are altered in major depression. However, no such studies have been published on current mania or hypomania. Case presentation In this single photon emission computed tomography (SPECT study with [123I]nor-β-CIT we present a case with simultaneous symptoms of major depression and hypomania. She had an elevated serotonin transporter availability (SERT in the midbrain and elevated dopamine transporter availability (DAT in the striatum, which normalised in a one-year follow-up period during which she received eight months of psychodynamic psychotherapy. Conclusions To our knowledge, this is the first report on SERT and DAT associated with mania. In our case the availability of both SERT in the midbrain and DAT in the striatum were elevated at baseline and declined during psychotherapy, while the SERT and DAT of the depressed controls increased during psychotherapy. Symptoms of hypomania in the case were alleviated during psychotherapy. Clinical recovery was also reflected in the Hamilton Depression Rating Scale (HDRS scores.

Convergence spasm due to aquaporin-positive neuromyelitis optica spectrum disorder

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Pınar Özçelik

2017-06-01

Full Text Available A female 27 presented with nausea and diplopia for 1 week. On examination she had normal vertical gaze but would develop convergence with miosis whenever she made horizontal saccades. Pupils were 6 mm and unreactive to light. MRI showed extensive hyperintensity in the dorsal midbrain and thalamus. Spinal MRI and CSF were both normal. Serum aquaporin-4-antibody was positive. She was treated with steroids and plasmapheresis and after 3 months convergence spasm resolved but pupils remained unreactive. Neuromyelitis optica often presents with brainstem signs, rarely a dorsal midbrain syndrome. Convergence spasm is occasionally of organic neurologic origin.

Midbrain adaptation may set the stage for the perception of musical beat.

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Rajendran, Vani G; Harper, Nicol S; Garcia-Lazaro, Jose A; Lesica, Nicholas A; Schnupp, Jan W H

2017-11-15

The ability to spontaneously feel a beat in music is a phenomenon widely believed to be unique to humans. Though beat perception involves the coordinated engagement of sensory, motor and cognitive processes in humans, the contribution of low-level auditory processing to the activation of these networks in a beat-specific manner is poorly understood. Here, we present evidence from a rodent model that midbrain preprocessing of sounds may already be shaping where the beat is ultimately felt. For the tested set of musical rhythms, on-beat sounds on average evoked higher firing rates than off-beat sounds, and this difference was a defining feature of the set of beat interpretations most commonly perceived by human listeners over others. Basic firing rate adaptation provided a sufficient explanation for these results. Our findings suggest that midbrain adaptation, by encoding the temporal context of sounds, creates points of neural emphasis that may influence the perceptual emergence of a beat. © 2017 The Authors.

Midbrain adaptation may set the stage for the perception of musical beat

Science.gov (United States)

2017-01-01

The ability to spontaneously feel a beat in music is a phenomenon widely believed to be unique to humans. Though beat perception involves the coordinated engagement of sensory, motor and cognitive processes in humans, the contribution of low-level auditory processing to the activation of these networks in a beat-specific manner is poorly understood. Here, we present evidence from a rodent model that midbrain preprocessing of sounds may already be shaping where the beat is ultimately felt. For the tested set of musical rhythms, on-beat sounds on average evoked higher firing rates than off-beat sounds, and this difference was a defining feature of the set of beat interpretations most commonly perceived by human listeners over others. Basic firing rate adaptation provided a sufficient explanation for these results. Our findings suggest that midbrain adaptation, by encoding the temporal context of sounds, creates points of neural emphasis that may influence the perceptual emergence of a beat. PMID:29118141

Upper midbrain profile sign and cingulate sulcus sign. MRI findings on sagittal images in idiopathic normal-pressure hydrocephalus, Alzheimer's disease, and progressive supranuclear palsy

International Nuclear Information System (INIS)

Adachi, Michito; Ohshima, Fumi; Kawanami, Toru; Kato, Takeo

2006-01-01

On magnetic resonance imaging (MRI) sagittal sections, we sometimes encounter abnormal aspects of the superior profile of the midbrain and the cingulate sulcus in patients with dementia. In this preliminary study, we refer to these findings as the ''upper midbrain profile sign'' and the cingulate sulcus sign.'' We prospectively evaluated the usefulness of these signs for the diagnosis of idiopathic normal-pressure hydrocephalus (iNPH), Alzheimer's disease (AD) and progressive supranuclear palsy (PSP). We evaluated the upper midbrain profile sign and the cingulate sulcus sign on MRI sagittal images obtained from 21 people with headaches but no neurological deficit (controls), 10 iNPH patients, 11 AD patients, and 5 PSP patients. The upper midbrain profile sign indicated a concave shape to the superior profile of the midbrain on mid-sagittal images, and the cingulate sulcus sign indicated a narrow, tight aspect of the posterior part of the cingulate sulcus on paramedian-sagittal images. These signs were never seen in any images from the controls. The upper midbrain profile sign was seen in 7 of 10 patients with iNPH, 5 of 11 with AD, and 3 of 5 with PSP. The cingulate sulcus sign was seen in all 10 patients with iNPH but was never seen in any patient with AD or PSP. The upper midbrain profile sign could support a diagnosis of PSP but cannot discriminate among iNPH, AD, and PSP. In contrast, the cingulate sulcus sign has a very high sensitivity for iNPH and should facilitate the distinction of iNPH from other dementias. In the clinical setting, it is momentous to evaluate these signs easily by one simple MRI sequence. (author)

FUSIMOTOR EFFECTS OF MIDBRAIN STIMULATION ON JAW MUSCLE-SPINDLES OF THE ANESTHETIZED CAT

NARCIS (Netherlands)

TAYLOR, A; JUCH, PJW

The effects of electrical stimulation within the midbrain on fusimotor output to the jaw elevator muscles were studied in anaesthetized cats. Muscle spindle afferents recorded in the mesencephalic trigeminal nucleus were categorised as primary or secondary by their responses to succinylcholine

Late onset arginase deficiency presenting with encephalopathy and midbrain hyperintensity

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Boby Varkey Maramattom

2016-01-01

Full Text Available Urea cycle disorders (UCD are very rare metabolic disorders that present with encephalopathy and hyperammonemia. Of the UCDs, Arginase deficiency (ARD is the rarest and presents in childhood with a progressive spastic diplegia or seizures. Acute presentation in adulthood is extremely unusual. [1] We present the first case of adult onset ARD presenting with encephalopathy and diffusion weighted MRI findings that resembled a moustache in the midbrain.

Dorsal onlay (Barbagli technique) versus dorsal inlay (Asopa technique) buccal mucosal graft urethroplasty for anterior urethral stricture: a prospective randomized study.

Science.gov (United States)

Aldaqadossi, Hussein; El Gamal, Samir; El-Nadey, Mohamed; El Gamal, Osama; Radwan, Mohamed; Gaber, Mohamed

2014-02-01

To compare both the dorsal onlay technique of Barbagli and the dorsal inlay technique of Asopa for the management of long anterior urethral stricture. From January 2010 to May 2012, a total of 47 patients with long anterior urethral strictures were randomized into two groups. The first group included 25 patients who were managed by dorsal onlay buccal mucosal graft urethroplasty. The second group included 22 patients who were managed by dorsal inlay buccal mucosal graft urethroplasty. Different clinical parameters, postoperative complications and success rates were compared between both groups. The overall success rate in the dorsal onlay group was 88%, whereas in the dorsal inlay group the success rate was 86.4% during the follow-up period. The mean operative time was significantly longer in the dorsal onlay urethroplasty group (205 ± 19.63 min) than in the dorsal inlay urethroplasty group (128 ± 4.9 min, P-value <0.0001). The average blood loss was significantly higher in the dorsal onlay urethroplasty group (228 ± 5.32 mL) than in the dorsal inlay urethroplasty group (105 ± 12.05 mL, P-value <0.0001). The dorsal onlay technique of Barbagli and the dorsal inlay technique of Asopa buccal mucosal graft urethroplasty provide similar success rates. The Asopa technique is easy to carry out, provides shorter operative time and less blood loss, and it is associated with fewer complications for anterior urethral stricture repair. © 2013 The Japanese Urological Association.

Midbrain Gene Screening Identifies a New Mesoaccumbal Glutamatergic Pathway and a Marker for Dopamine Cells Neuroprotected in Parkinson's Disease.

Science.gov (United States)

Viereckel, Thomas; Dumas, Sylvie; Smith-Anttila, Casey J A; Vlcek, Bianca; Bimpisidis, Zisis; Lagerström, Malin C; Konradsson-Geuken, Åsa; Wallén-Mackenzie, Åsa

2016-10-20

The ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) of the midbrain are associated with Parkinson's disease (PD), schizophrenia, mood disorders and addiction. Based on the recently unraveled heterogeneity within the VTA and SNc, where glutamate, GABA and co-releasing neurons have been found to co-exist with the classical dopamine neurons, there is a compelling need for identification of gene expression patterns that represent this heterogeneity and that are of value for development of human therapies. Here, several unique gene expression patterns were identified in the mouse midbrain of which NeuroD6 and Grp were expressed within different dopaminergic subpopulations of the VTA, and TrpV1 within a small heterogeneous population. Optogenetics-coupled in vivo amperometry revealed a previously unknown glutamatergic mesoaccumbal pathway characterized by TrpV1-Cre-expression. Human GRP was strongly detected in non-melanized dopaminergic neurons within the SNc of both control and PD brains, suggesting GRP as a marker for neuroprotected neurons in PD. This study thus unravels markers for distinct subpopulations of neurons within the mouse and human midbrain, defines unique anatomical subregions within the VTA and exposes an entirely new glutamatergic pathway. Finally, both TRPV1 and GRP are implied in midbrain physiology of importance to neurological and neuropsychiatric disorders.

Glucose modulates food-related salience coding of midbrain neurons in humans.

Science.gov (United States)

Ulrich, Martin; Endres, Felix; Kölle, Markus; Adolph, Oliver; Widenhorn-Müller, Katharina; Grön, Georg

2016-12-01

Although early rat studies demonstrated that administration of glucose diminishes dopaminergic midbrain activity, evidence in humans has been lacking so far. In the present functional magnetic resonance imaging study, glucose was intravenously infused in healthy human male participants while seeing images depicting low-caloric food (LC), high-caloric food (HC), and non-food (NF) during a food/NF discrimination task. Analysis of brain activation focused on the ventral tegmental area (VTA) as the origin of the mesolimbic system involved in salience coding. Under unmodulated fasting baseline conditions, VTA activation was greater during HC compared with LC food cues. Subsequent to infusion of glucose, this difference in VTA activation as a function of caloric load leveled off and even reversed. In a control group not receiving glucose, VTA activation during HC relative to LC cues remained stable throughout the course of the experiment. Similar treatment-specific patterns of brain activation were observed for the hypothalamus. The present findings show for the first time in humans that glucose infusion modulates salience coding mediated by the VTA. Hum Brain Mapp 37:4376-4384, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Electrosensory Midbrain Neurons Display Feature Invariant Responses to Natural Communication Stimuli.

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Tristan Aumentado-Armstrong

2015-10-01

Full Text Available Neurons that respond selectively but in an invariant manner to a given feature of natural stimuli have been observed across species and systems. Such responses emerge in higher brain areas, thereby suggesting that they occur by integrating afferent input. However, the mechanisms by which such integration occurs are poorly understood. Here we show that midbrain electrosensory neurons can respond selectively and in an invariant manner to heterogeneity in behaviorally relevant stimulus waveforms. Such invariant responses were not seen in hindbrain electrosensory neurons providing afferent input to these midbrain neurons, suggesting that response invariance results from nonlinear integration of such input. To test this hypothesis, we built a model based on the Hodgkin-Huxley formalism that received realistic afferent input. We found that multiple combinations of parameter values could give rise to invariant responses matching those seen experimentally. Our model thus shows that there are multiple solutions towards achieving invariant responses and reveals how subthreshold membrane conductances help promote robust and invariant firing in response to heterogeneous stimulus waveforms associated with behaviorally relevant stimuli. We discuss the implications of our findings for the electrosensory and other systems.

Electrosensory Midbrain Neurons Display Feature Invariant Responses to Natural Communication Stimuli.

Science.gov (United States)

Aumentado-Armstrong, Tristan; Metzen, Michael G; Sproule, Michael K J; Chacron, Maurice J

2015-10-01

Neurons that respond selectively but in an invariant manner to a given feature of natural stimuli have been observed across species and systems. Such responses emerge in higher brain areas, thereby suggesting that they occur by integrating afferent input. However, the mechanisms by which such integration occurs are poorly understood. Here we show that midbrain electrosensory neurons can respond selectively and in an invariant manner to heterogeneity in behaviorally relevant stimulus waveforms. Such invariant responses were not seen in hindbrain electrosensory neurons providing afferent input to these midbrain neurons, suggesting that response invariance results from nonlinear integration of such input. To test this hypothesis, we built a model based on the Hodgkin-Huxley formalism that received realistic afferent input. We found that multiple combinations of parameter values could give rise to invariant responses matching those seen experimentally. Our model thus shows that there are multiple solutions towards achieving invariant responses and reveals how subthreshold membrane conductances help promote robust and invariant firing in response to heterogeneous stimulus waveforms associated with behaviorally relevant stimuli. We discuss the implications of our findings for the electrosensory and other systems.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation.

Science.gov (United States)

Ravindran, Ethiraj; Hu, Hao; Yuzwa, Scott A; Hernandez-Miranda, Luis R; Kraemer, Nadine; Ninnemann, Olaf; Musante, Luciana; Boltshauser, Eugen; Schindler, Detlev; Hübner, Angela; Reinecker, Hans-Christian; Ropers, Hans-Hilger; Birchmeier, Carmen; Miller, Freda D; Wienker, Thomas F; Hübner, Christoph; Kaindl, Angela M

2017-04-01

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation

Science.gov (United States)

Yuzwa, Scott A.; Hernandez-Miranda, Luis R.; Musante, Luciana; Boltshauser, Eugen; Schindler, Detlev; Hübner, Angela; Reinecker, Hans-Christian; Ropers, Hans-Hilger; Miller, Freda D.; Hübner, Christoph; Kaindl, Angela M.

2017-01-01

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder. PMID:28453519

Functional Plasticity after Unilateral Vestibular Midbrain Infarction in Human Positron Emission Tomography

Science.gov (United States)

Becker-Bense, Sandra; Buchholz, Hans-Georg; Baier, Bernhard; Schreckenberger, Mathias; Bartenstein, Peter; Zwergal, Andreas; Brandt, Thomas; Dieterich, Marianne

2016-01-01

The aim of the study was to uncover mechanisms of central compensation of vestibular function at brainstem, cerebellar, and cortical levels in patients with acute unilateral midbrain infarctions presenting with an acute vestibular tone imbalance. Eight out of 17 patients with unilateral midbrain infarctions were selected on the basis of signs of a vestibular tone imbalance, e.g., graviceptive (tilts of perceived verticality) and oculomotor dysfunction (skew deviation, ocular torsion) in F18-fluordeoxyglucose (FDG)-PET at two time points: A) in the acute stage, and B) after recovery 6 months later. Lesion-behavior mapping analyses with MRI verified the exact structural lesion sites. Group subtraction analyses and comparisons with healthy controls were performed with Statistic Parametric Mapping for the PET data. A comparison of PET A of acute-stage patients with that of healthy controls showed increases in glucose metabolism in the cerebellum, motion-sensitive visual cortex areas, and inferior temporal lobe, but none in vestibular cortex areas. At the supratentorial level bilateral signal decreases dominated in the thalamus, frontal eye fields, and anterior cingulum. These decreases persisted after clinical recovery in contrast to the increases. The transient activations can be attributed to ocular motor and postural recovery (cerebellum) and sensory substitution of vestibular function for motion perception (visual cortex). The persisting deactivation in the thalamic nuclei and frontal eye fields allows alternative functional interpretations of the thalamic nuclei: either a disconnection of ascending sensory input occurs or there is a functional mismatch between expected and actual vestibular activity. Our data support the view that both thalami operate separately for each hemisphere but receive vestibular input from ipsilateral and contralateral midbrain integration centers. Normally they have gatekeeper functions for multisensory input to the cortex and automatic

Versatility of the ventral approach in bulbar urethroplasty using dorsal, ventral or dorsal plus ventral oral grafts

OpenAIRE

Palminteri, Enzo; Berdondini, Elisa; Fusco, Ferdinando; Nunzio, Cosimo De; Giannitsas, Kostas; Shokeir, Ahmed A.

2012-01-01

Objectives To investigate the versatility of the ventral urethrotomy approach in bulbar reconstruction with buccal mucosa (BM) grafts placed on the dorsal, ventral or dorsal plus ventral urethral surface. Patients and methods Between 1999 and 2008, 216 patients with bulbar strictures underwent BM graft urethroplasty using the ventral-sagittal urethrotomy approach. Of these patients, 32 (14.8%; mean stricture 3.2?cm, range 1.5?5) had a dorsal graft urethroplasty (DGU), 121 (56%; mean stricture...

Midbrain Gene Screening Identifies a New Mesoaccumbal Glutamatergic Pathway and a Marker for Dopamine Cells Neuroprotected in Parkinson’s Disease

Science.gov (United States)

Viereckel, Thomas; Dumas, Sylvie; Smith-Anttila, Casey J. A.; Vlcek, Bianca; Bimpisidis, Zisis; Lagerström, Malin C.; Konradsson-Geuken, Åsa; Wallén-Mackenzie, Åsa

2016-01-01

The ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) of the midbrain are associated with Parkinson’s disease (PD), schizophrenia, mood disorders and addiction. Based on the recently unraveled heterogeneity within the VTA and SNc, where glutamate, GABA and co-releasing neurons have been found to co-exist with the classical dopamine neurons, there is a compelling need for identification of gene expression patterns that represent this heterogeneity and that are of value for development of human therapies. Here, several unique gene expression patterns were identified in the mouse midbrain of which NeuroD6 and Grp were expressed within different dopaminergic subpopulations of the VTA, and TrpV1 within a small heterogeneous population. Optogenetics-coupled in vivo amperometry revealed a previously unknown glutamatergic mesoaccumbal pathway characterized by TrpV1-Cre-expression. Human GRP was strongly detected in non-melanized dopaminergic neurons within the SNc of both control and PD brains, suggesting GRP as a marker for neuroprotected neurons in PD. This study thus unravels markers for distinct subpopulations of neurons within the mouse and human midbrain, defines unique anatomical subregions within the VTA and exposes an entirely new glutamatergic pathway. Finally, both TRPV1 and GRP are implied in midbrain physiology of importance to neurological and neuropsychiatric disorders. PMID:27762319

Diversity of bilateral synaptic assemblies for binaural computation in midbrain single neurons.

Science.gov (United States)

He, Na; Kong, Lingzhi; Lin, Tao; Wang, Shaohui; Liu, Xiuping; Qi, Jiyao; Yan, Jun

2017-11-01

Binaural hearing confers many beneficial functions but our understanding of its underlying neural substrates is limited. This study examines the bilateral synaptic assemblies and binaural computation (or integration) in the central nucleus of the inferior colliculus (ICc) of the auditory midbrain, a key convergent center. Using in-vivo whole-cell patch-clamp, the excitatory and inhibitory postsynaptic potentials (EPSPs/IPSPs) of single ICc neurons to contralateral, ipsilateral and bilateral stimulation were recorded. According to the contralateral and ipsilateral EPSP/IPSP, 7 types of bilateral synaptic assemblies were identified. These include EPSP-EPSP (EE), E-IPSP (EI), E-no response (EO), II, IE, IO and complex-mode (CM) neurons. The CM neurons showed frequency- and/or amplitude-dependent EPSPs/IPSPs to contralateral or ipsilateral stimulation. Bilateral stimulation induced EPSPs/IPSPs that could be larger than (facilitation), similar to (ineffectiveness) or smaller than (suppression) those induced by contralateral stimulation. Our findings have allowed our group to characterize novel neural circuitry for binaural computation in the midbrain. Copyright © 2017 Elsevier B.V. All rights reserved.

Hierarchical prediction errors in midbrain and septum during social learning.

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Diaconescu, Andreea O; Mathys, Christoph; Weber, Lilian A E; Kasper, Lars; Mauer, Jan; Stephan, Klaas E

2017-04-01

Social learning is fundamental to human interactions, yet its computational and physiological mechanisms are not well understood. One prominent open question concerns the role of neuromodulatory transmitters. We combined fMRI, computational modelling and genetics to address this question in two separate samples (N = 35, N = 47). Participants played a game requiring inference on an adviser's intentions whose motivation to help or mislead changed over time. Our analyses suggest that hierarchically structured belief updates about current advice validity and the adviser's trustworthiness, respectively, depend on different neuromodulatory systems. Low-level prediction errors (PEs) about advice accuracy not only activated regions known to support 'theory of mind', but also the dopaminergic midbrain. Furthermore, PE responses in ventral striatum were influenced by the Met/Val polymorphism of the Catechol-O-Methyltransferase (COMT) gene. By contrast, high-level PEs ('expected uncertainty') about the adviser's fidelity activated the cholinergic septum. These findings, replicated in both samples, have important implications: They suggest that social learning rests on hierarchically related PEs encoded by midbrain and septum activity, respectively, in the same manner as other forms of learning under volatility. Furthermore, these hierarchical PEs may be broadcast by dopaminergic and cholinergic projections to induce plasticity specifically in cortical areas known to represent beliefs about others. © The Author (2017). Published by Oxford University Press.

A Comparative Study of Dorsal Buccal Mucosa Graft Substitution Urethroplasty by Dorsal Urethrotomy Approach versus Ventral Sagittal Urethrotomy Approach

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Mrinal Pahwa

2013-01-01

Full Text Available Objectives. To compare the outcome of dorsal buccal mucosal graft (BMG substitution urethroplasty by dorsal urethrotomy approach with ventral urethrotomy approach in management of stricture urethra. Methods and Materials. A total of 40 patients who underwent dorsal BMG substitution urethroplasty were randomized into two groups. 20 patients underwent dorsal onlay BMG urethroplasty as described by Barbagli, and the other 20 patients underwent dorsal BMG urethroplasty by ventral urethrotomy as described by Asopa. Operative time, success rate, satisfaction rate, and complications were compared between the two groups. Mean follow-up was 12 months (6–24 months. Results. Ventral urethrotomy group had considerably lesser operative time although the difference was not statistically significant. Patients in dorsal group had mean maximum flow rate of 19.6 mL/min and mean residual urine of 27 mL, whereas ventral group had a mean maximum flow rate of 18.8 and residual urine of 32 mL. Eighteen out of twenty patients voided well in each group, and postoperative imaging study in these patients showed a good lumen with no evidence of leak or extravasation. Conclusion. Though ventral sagittal urethrotomy preserves the blood supply of urethra and intraoperative time was less than dorsal urethrotomy technique, there was no statistically significant difference in final outcome using either technique.

A Comparative Study of Dorsal Buccal Mucosa Graft Substitution Urethroplasty by Dorsal Urethrotomy Approach versus Ventral Sagittal Urethrotomy Approach.

Science.gov (United States)

Pahwa, Mrinal; Gupta, Sanjeev; Pahwa, Mayank; Jain, Brig D K; Gupta, Manu

2013-01-01

Objectives. To compare the outcome of dorsal buccal mucosal graft (BMG) substitution urethroplasty by dorsal urethrotomy approach with ventral urethrotomy approach in management of stricture urethra. Methods and Materials. A total of 40 patients who underwent dorsal BMG substitution urethroplasty were randomized into two groups. 20 patients underwent dorsal onlay BMG urethroplasty as described by Barbagli, and the other 20 patients underwent dorsal BMG urethroplasty by ventral urethrotomy as described by Asopa. Operative time, success rate, satisfaction rate, and complications were compared between the two groups. Mean follow-up was 12 months (6-24 months). Results. Ventral urethrotomy group had considerably lesser operative time although the difference was not statistically significant. Patients in dorsal group had mean maximum flow rate of 19.6 mL/min and mean residual urine of 27 mL, whereas ventral group had a mean maximum flow rate of 18.8 and residual urine of 32 mL. Eighteen out of twenty patients voided well in each group, and postoperative imaging study in these patients showed a good lumen with no evidence of leak or extravasation. Conclusion. Though ventral sagittal urethrotomy preserves the blood supply of urethra and intraoperative time was less than dorsal urethrotomy technique, there was no statistically significant difference in final outcome using either technique.

Selective increase of in vivo firing frequencies in DA SN neurons after proteasome inhibition in the ventral midbrain.

Science.gov (United States)

Subramaniam, Mahalakshmi; Kern, Beatrice; Vogel, Simone; Klose, Verena; Schneider, Gaby; Roeper, Jochen

2014-09-01

The impairment of protein degradation via the ubiquitin-proteasome system (UPS) is present in sporadic Parkinson's disease (PD), and might play a key role in selective degeneration of vulnerable dopamine (DA) neurons in the substantia nigra pars compacta (SN). Further evidence for a causal role of dysfunctional UPS in familial PD comes from mutations in parkin, which results in a loss of function of an E3-ubiquitin-ligase. In a mouse model, genetic inactivation of an essential component of the 26S proteasome lead to widespread neuronal degeneration including DA midbrain neurons and the formation of alpha-synuclein-positive inclusion bodies, another hallmark of PD. Studies using pharmacological UPS inhibition in vivo had more mixed results, varying from extensive degeneration to no loss of DA SN neurons. However, it is currently unknown whether UPS impairment will affect the neurophysiological functions of DA midbrain neurons. To answer this question, we infused a selective proteasome inhibitor into the ventral midbrain in vivo and recorded single DA midbrain neurons 2 weeks after the proteasome challenge. We found a selective increase in the mean in vivo firing frequencies of identified DA SN neurons in anesthetized mice, while those in the ventral tegmental area (VTA) were unaffected. Our results demonstrate that a single-hit UPS inhibition is sufficient to induce a stable and selective hyperexcitability phenotype in surviving DA SN neurons in vivo. This might imply that UPS dysfunction sensitizes DA SN neurons by enhancing 'stressful pacemaking'. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Alzheimer disease: functional abnormalities in the dorsal visual pathway.

LENUS (Irish Health Repository)

Bokde, Arun L W

2012-02-01

PURPOSE: To evaluate whether patients with Alzheimer disease (AD) have altered activation compared with age-matched healthy control (HC) subjects during a task that typically recruits the dorsal visual pathway. MATERIALS AND METHODS: The study was performed in accordance with the Declaration of Helsinki, with institutional ethics committee approval, and all subjects provided written informed consent. Two tasks were performed to investigate neural function: face matching and location matching. Twelve patients with mild AD and 14 age-matched HC subjects were included. Brain activation was measured by using functional magnetic resonance imaging. Group statistical analyses were based on a mixed-effects model corrected for multiple comparisons. RESULTS: Task performance was not statistically different between the two groups, and within groups there were no differences in task performance. In the HC group, the visual perception tasks selectively activated the visual pathways. Conversely in the AD group, there was no selective activation during performance of these same tasks. Along the dorsal visual pathway, the AD group recruited additional regions, primarily in the parietal and frontal lobes, for the location-matching task. There were no differences in activation between groups during the face-matching task. CONCLUSION: The increased activation in the AD group may represent a compensatory mechanism for decreased processing effectiveness in early visual areas of patients with AD. The findings support the idea that the dorsal visual pathway is more susceptible to putative AD-related neuropathologic changes than is the ventral visual pathway.

PROJECTIONS OF DORSAL AND MEDIAN RAPHE NUCLEI TO DORSAL AND VENTRAL STRIATUM

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G. R. Hassanzadeh G. Behzadi

2007-08-01

Full Text Available The ascending serotonergic projections are derived mainly from mesencephalic raphe nuclei. Topographical projections from mesencephalic raphe nuclei to the striatum were examined in the rat by the retrograde transport technique of HRP (horseradish peroxidase. In 29 rats stereotaxically injection of HRP enzyme were performed in dorsal and ventral parts of striatum separately. The extent of the injection sites and distribution of retrogradely labeled neuronal cell bodies were drawed on representative sections using a projection microscope. Following ipsilateral injection of HRP into the dorsal striatum, numerous labeled neurons were seen in rostral portion of dorsal raphe (DR nucleus. In the same level the cluster of labeled neurons were hevier through caudal parts of DR. A few neurons were also located in lateral wing of DR. More caudally some labeled neurons were found in lateral, medial line of DR. In median raphe nucleus (MnR the labeled neurons were scattered only in median portion of this nucleus. The ipsilateral injection of HRP into the ventral region of striatum resulted on labeling of numerous neurons in rostral, caudal and lateral portions of DR. Through the caudal extension of DR on 4th ventricle level, a large number of labeled neurons were distributed along the ventrocaudal parts of DR. In MnR, labeled neurons were observed only in median part of this nucleus. These findings suggest the mesencephalic raphe nuclei projections to caudo-putamen are topographically organized. In addition dorsal and median raphe nuclei have a stronger projection to the ventral striatum.

Acute Psychosis Associated with Subcortical Stroke: Comparison between Basal Ganglia and Mid-Brain Lesions

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Aaron McMurtray

2014-01-01

Full Text Available Acute onset of psychosis in an older or elderly individual without history of previous psychiatric disorders should prompt a thorough workup for neurologic causes of psychiatric symptoms. This report compares and contrasts clinical features of new onset of psychotic symptoms between two patients, one with an acute basal ganglia hemorrhagic stroke and another with an acute mid-brain ischemic stroke. Delusions and hallucinations due to basal ganglia lesions are theorized to develop as a result of frontal lobe dysfunction causing impairment of reality checking pathways in the brain, while visual hallucinations due to mid-brain lesions are theorized to develop due to dysregulation of inhibitory control of the ponto-geniculate-occipital system. Psychotic symptoms occurring due to stroke demonstrate varied clinical characteristics that depend on the location of the stroke within the brain. Treatment with antipsychotic medications may provide symptomatic relief.

Tactile spatial working memory activates the dorsal extrastriate cortical pathway in congenitally blind individuals.

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Bonino, D; Ricciardi, E; Sani, L; Gentili, C; Vanello, N; Guazzelli, M; Vecchi, T; Pietrini, P

2008-09-01

In sighted individuals, both the visual and tactile version of the same spatial working memory task elicited neural responses in the dorsal "where" cortical pathway (Ricciardi et al., 2006). Whether the neural response during the tactile working memory task is due to visually-based spatial imagery or rather reflects a more abstract, supramodal organization of the dorsal cortical pathway remains to be determined. To understand the role of visual experience on the functional organization of the dorsal cortical stream, using functional magnetic resonance imaging (fMRI) here we examined brain response in four individuals with congenital or early blindness and no visual recollection, while they performed the same tactile spatial working memory task, a one-back recognition of 2D and 3D matrices. The blind subjects showed a significant activation in bilateral posterior parietal cortex, dorsolateral and inferior prefrontal areas, precuneus, lateral occipital cortex, and cerebellum. Thus, dorsal occipito-parietal areas are involved in mental imagery dealing with spatial components in subjects without prior visual experience and in response to a non-visual task. These data indicate that recruitment of the dorsal cortical pathway in response to the tactile spatial working memory task is not mediated by visually-based imagery and that visual experience is not a prerequisite for the development of a more abstract functional organization of the dorsal stream. These findings, along with previous data indicating a similar supramodal functional organization within the ventral cortical pathway and the motion processing brain regions, may contribute to explain how individuals who are born deprived of sight are able to interact effectively with the surrounding world.

The β-chemokines CCL2 and CCL7 are two novel differentiation factors for midbrain dopaminergic precursors and neurons

International Nuclear Information System (INIS)

Edman, Linda C.; Mira, Helena; Arenas, Ernest

2008-01-01

β-chemokines are secreted factors that regulate diverse functions in the adult brain, such as neuro-immune responses and neurotransmission, but their function in the developing brain is largely unknown. We recently found that the orphan nuclear receptor, Nurr1, up regulates CCL2 and CCL7 in neural stem cells, suggesting a possible function of β-chemokines in midbrain development. Here we report that two β-chemokines, CCL2 and CCL7, and two of their receptors, CCR1 and CCR2, are expressed and developmentally regulated in the ventral midbrain (VM). Moreover, we found that the expression of CCL7 was down regulated in the Nurr1 knockout mice, linking CCL7 to dopamine (DA) neuron development. When the function of CCL2 and CCL7 was examined, we found that they selectively enhanced the differentiation of Nurr1+ precursors into DA neurons, but not their survival or progenitor proliferation in primary precursor cultures. Moreover, both CCL2 and CCL7 promoted neuritogenesis in midbrain DA neuron cultures. Thus, our results show for the first time a function of β-chemokines in the developing brain and identify β-chemokines as novel class of pro-differentiation factors for midbrain DA neurons. These data also suggest that β-chemokines may become useful tools to enhance the differentiation of DA cell preparations for cell replacement therapy and drug discovery in Parkinson's disease (PD)

Isolated Bilateral Fourth Cranial Nerve Palsies as the Presenting Sign of Hydrocephalus

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Dimosthenis Mantopoulos

2011-07-01

Full Text Available Midbrain lesions leading to bilateral fourth nerve palsies are typically accompanied by other brainstem symptomatology. Here we report a case of a 29-year-old man with hydrocephalus and significant third ventricle dilation applying pressure on the dorsal midbrain and having as the only manifestation isolated, bilateral fourth cranial nerve palsies. This finding, reported here for the first time, could be attributed to a partially working ventriculoperitoneal shunt previously placed in this patient, which was able to sporadically relieve the increases of the intraventricular pressure on the midbrain that would normally lead to other manifestations.

A biomechanical comparison of four fixed-angle dorsal plates in a finite element model of dorsally-unstable radius fracture.

Science.gov (United States)

Knežević, Josip; Kodvanj, Janoš; Čukelj, Fabijan; Pamuković, Frane; Pavić, Arsen

2017-11-01

To compare the finite element models of two different composite radius fracture patterns, reduced and stabilised with four different fixed-angle dorsal plates during axial, dorsal and volar loading conditions. Eight different plastic models representing four AO/ASIF type 23-A3 distal radius fractures and four AO/ASIF 23-C2 distal radius fractures were obtained and fixed each with 1 of 4 methods: a standard dorsal non-anatomical fixed angle T-plate (3.5mm Dorsal T-plate, Synthes), anatomical fixed-angle double plates (2.4mm LCP Dorsal Distal Radius, Synthes), anatomical fixed angle T-plate (2.4mm Acu-Loc Dorsal Plate, Acumed) or anatomical variable-angle dorsal T-plate (3.5mm, Dorsal Plate, Zrinski). Composite radius with plate and screws were scanned with a 3D optical scanner and later processed in Abaqus Software to generate the finite element model. All models were axially loaded at 3 points (centrally, volarly and dorsally) with 50 N forces to avoid the appearance of plastic deformations of the models. Total displacements at the end of the bone and the stresses in the bones and plates were determined and compared. Maximal von Mises stress in bone for 3-part fracture models was very similar to that in 2-part fracture models. The biggest difference between models and the largest displacements were seen during volar loading. The stresses in all models were the highest above the fracture gap. The best performance in all parameters tested was with the Zrinski plate and the most modest results were with the Synthes T-plate. There was no significant difference between 2-part (AO/ASIF type 23-A3) and 3-part (AO/ASIF 23-C2) fracture models. Maximal stresses in the plates appeared above the fracture gap; therefore, it is worth considering the development of plates without screw holes above the gap. © 2017 Elsevier Ltd. All rights reserved.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation.

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Ethiraj Ravindran

2017-04-01

Full Text Available Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder.

Personal authentication through dorsal hand vein patterns

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Hsu, Chih-Bin; Hao, Shu-Sheng; Lee, Jen-Chun

2011-08-01

Biometric identification is an emerging technology that can solve security problems in our networked society. A reliable and robust personal verification approach using dorsal hand vein patterns is proposed in this paper. The characteristic of the approach needs less computational and memory requirements and has a higher recognition accuracy. In our work, the near-infrared charge-coupled device (CCD) camera is adopted as an input device for capturing dorsal hand vein images, it has the advantages of the low-cost and noncontact imaging. In the proposed approach, two finger-peaks are automatically selected as the datum points to define the region of interest (ROI) in the dorsal hand vein images. The modified two-directional two-dimensional principal component analysis, which performs an alternate two-dimensional PCA (2DPCA) in the column direction of images in the 2DPCA subspace, is proposed to exploit the correlation of vein features inside the ROI between images. The major advantage of the proposed method is that it requires fewer coefficients for efficient dorsal hand vein image representation and recognition. The experimental results on our large dorsal hand vein database show that the presented schema achieves promising performance (false reject rate: 0.97% and false acceptance rate: 0.05%) and is feasible for dorsal hand vein recognition.

Direct lineage reprogramming of mouse fibroblasts to functional midbrain dopaminergic neuronal progenitors

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Han-Seop Kim

2014-01-01

Full Text Available The direct lineage reprogramming of somatic cells to other lineages by defined factors has led to innovative cell-fate-change approaches for providing patient-specific cells. Recent reports have demonstrated that four pluripotency factors (Oct4, Sox2, Klf4, and c-Myc are sufficient to directly reprogram fibroblasts to other specific cells, including induced neural stem cells (iNSCs. Here, we show that mouse fibroblasts can be directly reprogrammed into midbrain dopaminergic neuronal progenitors (DPs by temporal expression of the pluripotency factors and environment containing sonic hedgehog and fibroblast growth factor 8. Within thirteen days, self-renewing and functional induced DPs (iDPs were generated. Interestingly, the inhibition of both Jak and Gsk3β notably enhanced the iDP reprogramming efficiency. We confirmed the functionality of the iDPs by showing that the dopaminergic neurons generated from iDPs express midbrain markers, release dopamine, and show typical electrophysiological profiles. Our results demonstrate that the pluripotency factors-mediated direct reprogramming is an invaluable strategy for supplying functional and proliferating iDPs and may be useful for other neural progenitors required for disease modeling and cell therapies for neurodegenerative disorders.

Neuroradiological evaluation of dorsal cyst malformations

International Nuclear Information System (INIS)

Utsunomiya, Hidetsuna; Hayashi, Takashi; Hashimoto, Takeo; Matsuishi, Toyojiro; Okudera, Toshio.

1988-01-01

We discussed six cases with dorsal cyst malformations listing their neuroradiological observations and proposed to differentiate between the holosphere and hemisphere as defined by Yokota (1984). The cases were divided into holospheric and hemispheric groups depending on the continuity of their frontal lobe midlines. Cases 1, 2 and 3 were placed in the holospheric group because of their unseparated frontal lobe sbeneath the partially formed anterior interhemispheric fissures. Cases 4, 5 and 6 were grouped in the hemisphere due to the completion of the interhemispheric fissures. There has been a tendency in recent years for most cases of cerebral malformations having an endogenous dorsal cyst with monoventricular configuration to be diagnosed as holoprosencephaly. However, we believe that only patients who have a dorsal cyst in the holospheric brain should be included, and the others in the hemispheric brain, which is capable of completing hemispheric cleavage, should not. Therefore, we emphasize the importance of correctly identifying the holospheric state in the dorsal cyst malformations for diagnosing holoprosencephaly. (author)

Long-Term Impairment of Sound Processing in the Auditory Midbrain by Daily Short-Term Exposure to Moderate Noise

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Liang Cheng

2017-01-01

Full Text Available Most citizen people are exposed daily to environmental noise at moderate levels with a short duration. The aim of the present study was to determine the effects of daily short-term exposure to moderate noise on sound level processing in the auditory midbrain. Sound processing properties of auditory midbrain neurons were recorded in anesthetized mice exposed to moderate noise (80 dB SPL, 2 h/d for 6 weeks and were compared with those from age-matched controls. Neurons in exposed mice had a higher minimum threshold and maximum response intensity, a longer first spike latency, and a higher slope and narrower dynamic range for rate level function. However, these observed changes were greater in neurons with the best frequency within the noise exposure frequency range compared with those outside the frequency range. These sound processing properties also remained abnormal after a 12-week period of recovery in a quiet laboratory environment after completion of noise exposure. In conclusion, even daily short-term exposure to moderate noise can cause long-term impairment of sound level processing in a frequency-specific manner in auditory midbrain neurons.

CALBINDIN CONTENT AND DIFFERENTIAL VULNERABILITY OF MIDBRAIN EFFERENT DOPAMINERGIC NEURONS IN MACAQUES

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Iria G Dopeso-Reyes

2014-12-01

Full Text Available Calbindin (CB is a calcium binding protein reported to protect dopaminergic neurons from degeneration. Although a direct link between CB content and differential vulnerability of dopaminergic neurons has long been accepted, factors other than CB have also been suggested, particularly those related to the dopamine transporter. Indeed, several studies have reported that CB levels are not causally related to the differential vulnerability of dopaminergic neurons against neurotoxins. Here we have used dual stains for tyrosine hydroxylase (TH and CB in 3 control and 3 MPTP-treated monkeys to visualize dopaminergic neurons in the ventral tegmental area (VTA and in the dorsal and ventral tiers of the substantia nigra pars compacta (SNcd and SNcv co-expressing TH and CB. In control animals, the highest percentages of co-localization were found in VTA (58.2%, followed by neurons located in the SNcd (34.7%. As expected, SNcv neurons lacked CB expression. In MPTP-treated animals, the percentage of CB-ir/TH-ir neurons in the VTA was similar to control monkeys (62.1%, whereas most of the few surviving neurons in the SNcd were CB-ir/TH-ir (88.6%. Next, we have elucidated the presence of CB within identified nigrostriatal and nigroextrastriatal midbrain dopaminergic projection neurons. For this purpose, two control monkeys received one injection of Fluoro-Gold into the caudate nucleus and one injection of cholera toxin (CTB into the postcommissural putamen, whereas two more monkeys were injected with CTB into the internal division of the globus pallidus. As expected, all the nigrocaudate- and nigroputamen-projecting neurons were TH-ir, although surprisingly, all of these nigrostriatal-projecting neurons were negative for CB. Furthermore, all the nigropallidal-projecting neurons co-expressed both TH and CB. In summary, although CB-ir dopaminergic neurons seem to be less prone to MPTP-induced degeneration, our data clearly demonstrated that these neurons are not

Vertical diplopia and oscillopsia due to midbrain keyhole aqueduct syndrome associated with severe cough

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Angela Jinsook Oh

2018-06-01

Full Text Available Purpose: Midline structural defects in the neural axis can give rise to neuro-ophthalmic symptoms. We report a rare case of keyhole aqueduct syndrome presenting after two years of severe cough due to gastroesophageal reflux disease. Observations: A 58-year-old woman with a 2-year history of daily, severe cough presented to the neuro-ophthalmology clinic with progressive diplopia and oscillopsia. Examination revealed a 1–2 Hz down-beating nystagmus in primary gaze that worsened with left, right, and down gazes. Gaze evoked nystagmus and mild paresis were also seen with up gaze. There was an incomitant left hypertropia due to skew deviation that worsened with right and up gazes and improved with down gaze. She also had a right-sided ptosis and a 3 mm anisocoria not due to cranial nerve 3 paresis or Horner's syndrome. Brain magnetic resonance imaging showed a 1.5 mm × 11.7 mm × 6 mm midline cleft in the ventral midbrain communicating with the cerebral aqueduct, consistent with keyhole aqueduct syndrome. Her nystagmus and diplopia improved with oral acetazolamide treatment, at high doses of 2500–3000 mg per day. Conclusions and importance: We report the first case of midbrain keyhole aqueduct syndrome with ocular motor and other neuro-ophthalmic manifestations associated with severe cough. Although her cough was effectively treated and intracranial pressure measurement was normal, her ophthalmic symptoms continued to progress, which is common in previous cases reported. Treatment with acetazolamide led to significant improvement, supporting the use of acetazolamide in this rare condition. Keywords: Keyhole aqueduct syndrome, Midbrain cleft, Mesencephalic cleft, Syrinx, Syringobulbia, Down-beating nystagmus, Cerebrospinal fluid

Sunscreen Use on the Dorsal Hands at the Beach

International Nuclear Information System (INIS)

Warren, D. B.; Hobbs, J. B.; Jr, R. F. W.; Riahi, R. R.

2013-01-01

Since skin of the dorsal hands is a known site for the development of cutaneous squamous cell carcinoma, an epidemiologic investigation was needed to determine if beachgoers apply sunscreen to the dorsal aspect of their hands as frequently as they apply it to other skin sites. Aim. The aim of the current study was to compare the use of sunscreen on the dorsal hands to other areas of the body during subtropical late spring and summer sunlight exposure at the beach. Materials and Methods. A cross-sectional survey from a convenience sample of beachgoers was designed to evaluate responded understanding and protective measures concerning skin cancer on the dorsal hands in an environment with high natural UVR exposure. Results. A total of 214 surveys were completed and analyzed. Less than half of subjects (105, 49%) applied sunscreen to their dorsal hands. Women applied sunscreen to the dorsal hands more than men (55% women versus 40% men, ρ=0.04 ). Higher Fitzpatrick Skin Type respondents were less likely to protect their dorsal hands from ultraviolet radiation (ρ=0.001 ). Conclusions. More public education focused on dorsal hand protection from ultraviolet radiation damage is necessary to reduce the risk for squamous cell carcinomas of the hands.

vox homeobox gene: a novel regulator of midbrain-hindbrain boundary development in medaka fish?

Czech Academy of Sciences Publication Activity Database

Fabian, Peter; Pantzartzi, Chrysoula; Kozmiková, Iryna; Kozmik, Zbyněk

2016-01-01

Roč. 226, č. 2 (2016), s. 99-107 ISSN 0949-944X R&D Projects: GA MŠk LO1419 Institutional support: RVO:68378050 Keywords : Midbrain-hindbrain boundary * vox * medaka * Heat shock element * fgf8 * Gene regulatory network Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.422, year: 2016

Wnt5a-treated midbrain neural stem cells improve dopamine cell replacement therapy in parkinsonian mice

DEFF Research Database (Denmark)

Parish, Clare L; Castelo-Branco, Gonçalo; Rawal, Nina

2008-01-01

have prevented their clinical application. We present here a method for generating large numbers of DA neurons based on expanding and differentiating ventral midbrain (VM) neural stem cells/progenitors in the presence of key signals necessary for VM DA neuron development. Mouse VM neurospheres (VMNs......Dopamine (DA) cell replacement therapy in Parkinson disease (PD) can be achieved using human fetal mesencephalic tissue; however, limited tissue availability has hindered further developments. Embryonic stem cells provide a promising alternative, but poor survival and risk of teratoma formation......) expanded with FGF2, differentiated with sonic hedgehog and FGF8, and transfected with Wnt5a (VMN-Wnt5a) generated 10-fold more DA neurons than did conventional FGF2-treated VMNs. VMN-Wnt5a cells exhibited the transcriptional and biochemical profiles and intrinsic electrophysiological properties of midbrain...

Arterial blood supply to the thalamus and midbrain on CT sections, 2

International Nuclear Information System (INIS)

Takeshita, Gen; Ottomo, Michinori; Satoh, Nobuko; Yokoyama, Yoshiaki.

1984-01-01

The selective injection of a dyestuff into thalamoperforating arteries from the posterior part of the circle of Willis, using five postmortem brains, was performed. After fixation, sections parallel to the orbito-meatal line were obtained. In cases which showed a standard development of the posterior communicating arteries, the usual patterns were as follows: the area supplied by perforators of the posterior communicating artery (anterior thalamoperforating artery) was visualized in the hypothalamus and the antero-lateral part of the thalamus; the area supplied by perforators of the proximal segment of the posterior cerebral artery (interpeduncular thalamoperforating artery) was visualized in the midbrain and the medial part of thalamus; the area supplied by perforators of the ambient segment of the posterior cerebral artery (thalamogeniculate artery) was visualized in the medial part of the geniculate body and the posterior part of the thalamus. According to the development of the posterior communicating artery, the area supplied by each perforator was quite variable. Three CT sections were obtained containing three different patterns of the posterior communicating artery: 1) well-developed; 2) moderately developed; and 3) poorly developed. The identification of the area supplied by thalamoperforating arteries on CT sections was quite useful in the CT diagnosis of cerebrovascular disorders which involved the thalamus and the midbrain. (author)

Midbrain dopamine neurons associated with reward processing innervate the neurogenic subventricular zone.

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Lennington, Jessica B; Pope, Sara; Goodheart, Anna E; Drozdowicz, Linda; Daniels, Stephen B; Salamone, John D; Conover, Joanne C

2011-09-14

Coordinated regulation of the adult neurogenic subventricular zone (SVZ) is accomplished by a myriad of intrinsic and extrinsic factors. The neurotransmitter dopamine is one regulatory molecule implicated in SVZ function. Nigrostriatal and ventral tegmental area (VTA) midbrain dopamine neurons innervate regions adjacent to the SVZ, and dopamine synapses are found on SVZ cells. Cell division within the SVZ is decreased in humans with Parkinson's disease and in animal models of Parkinson's disease following exposure to toxins that selectively remove nigrostriatal neurons, suggesting that dopamine is critical for SVZ function and nigrostriatal neurons are the main suppliers of SVZ dopamine. However, when we examined the aphakia mouse, which is deficient in nigrostriatal neurons, we found no detrimental effect to SVZ proliferation or organization. Instead, dopamine innervation of the SVZ tracked to neurons at the ventrolateral boundary of the VTA. This same dopaminergic neuron population also innervated the SVZ of control mice. Characterization of these neurons revealed expression of proteins indicative of VTA neurons. Furthermore, exposure to the neurotoxin MPTP depleted neurons in the ventrolateral VTA and resulted in decreased SVZ proliferation. Together, these results reveal that dopamine signaling in the SVZ originates from a population of midbrain neurons more typically associated with motivational and reward processing.

Agenesis of the dorsal pancreas

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Schnedl, Wolfgang J; Piswanger-Soelkner, Claudia; Wallner, Sandra J; Krause, Robert; Lipp, Rainer W

2009-01-01

During the last 100 years in medical literature, there are only 54 reports, including the report of Pasaoglu et al (World J Gastroenterol 2008; 14: 2915-2916), with clinical descriptions of agenesis of the dorsal pancreas in humans. Agenesis of the dorsal pancreas, a rare congenital pancreatic malformation, is associated with some other medical conditions such as hyperglycemia, abdominal pain, pancreatitis and a few other diseases. In approximately 50% of reported patients with this congenital malformation, hyperglycemia was demonstrated. Evaluation of hyperglycemia and diabetes mellitus in all patients with agenesis of the dorsal pancreas including description of fasting blood glucose, oral glucose tolerance test, glycated hemoglobin and medical treatment would be a future goal. Since autosomal dominant transmission has been suggested in single families, more family studies including imaging technologies with demonstration of the pancreatic duct system are needed for evaluation of this disease. With this letter to the editor, we aim to increase available information for the better understanding of this rare disease. PMID:19140241

Emergent properties during dorsal closure in Drosophila morphogenesis

International Nuclear Information System (INIS)

Peralta, X G; Toyama, Y; Edwards, G S; Kiehart, D P

2008-01-01

Dorsal closure is an essential stage of Drosophila development that is a model system for research in morphogenesis and biological physics. Dorsal closure involves an orchestrated interplay between gene expression and cell activities that produce shape changes, exert forces and mediate tissue dynamics. We investigate the dynamics of dorsal closure based on confocal microscopic measurements of cell shortening in living embryos. During the mid-stages of dorsal closure we find that there are fluctuations in the width of the leading edge cells but the time-averaged analysis of measurements indicate that there is essentially no net shortening of cells in the bulk of the leading edge, that contraction predominantly occurs at the canthi as part of the process for zipping together the two leading edges of epidermis and that the rate constant for zipping correlates with the rate of movement of the leading edges. We characterize emergent properties that regulate dorsal closure, i.e., a velocity governor and the coordination and synchronization of tissue dynamics

FoxA4 favours notochord formation by inhibiting contiguous mesodermal fates and restricts anterior neural development in Xenopus embryos.

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Murgan, Sabrina; Castro Colabianchi, Aitana Manuela; Monti, Renato José; Boyadjián López, Laura Elena; Aguirre, Cecilia E; Stivala, Ernesto González; Carrasco, Andrés E; López, Silvia L

2014-01-01

In vertebrates, the embryonic dorsal midline is a crucial signalling centre that patterns the surrounding tissues during development. Members of the FoxA subfamily of transcription factors are expressed in the structures that compose this centre. Foxa2 is essential for dorsal midline development in mammals, since knock-out mouse embryos lack a definitive node, notochord and floor plate. The related gene foxA4 is only present in amphibians. Expression begins in the blastula -chordin and -noggin expressing centre (BCNE) and is later restricted to the dorsal midline derivatives of the Spemann's organiser. It was suggested that the early functions of mammalian foxa2 are carried out by foxA4 in frogs, but functional experiments were needed to test this hypothesis. Here, we show that some important dorsal midline functions of mammalian foxa2 are exerted by foxA4 in Xenopus. We provide new evidence that the latter prevents the respecification of dorsal midline precursors towards contiguous fates, inhibiting prechordal and paraxial mesoderm development in favour of the notochord. In addition, we show that foxA4 is required for the correct regionalisation and maintenance of the central nervous system. FoxA4 participates in constraining the prospective rostral forebrain territory during neural specification and is necessary for the correct segregation of the most anterior ectodermal derivatives, such as the cement gland and the pituitary anlagen. Moreover, the early expression of foxA4 in the BCNE (which contains precursors of the whole forebrain and most of the midbrain and hindbrain) is directly required to restrict anterior neural development.

Endogenous neurotrophin-3 promotes neuronal sprouting from dorsal root ganglia.

Science.gov (United States)

Wang, Xu-Yang; Gu, Pei-Yuan; Chen, Shi-Wen; Gao, Wen-Wei; Tian, Heng-Li; Lu, Xiang-He; Zheng, Wei-Ming; Zhuge, Qi-Chuan; Hu, Wei-Xing

2015-11-01

In the present study, we investigated the role of endogenous neurotrophin-3 in nerve terminal sprouting 2 months after spinal cord dorsal root rhizotomy. The left L1-5 and L7-S2 dorsal root ganglia in adult cats were exposed and removed, preserving the L6 dorsal root ganglia. Neurotrophin-3 was mainly expressed in large neurons in the dorsal root ganglia and in some neurons in spinal lamina II. Two months after rhizotomy, the number of neurotrophin-3-positive neurons in the spared dorsal root ganglia and the density of neurite sprouts emerging from these ganglia were increased. Intraperitoneal injection of an antibody against neurotrophin-3 decreased the density of neurite sprouts. These findings suggest that endogenous neurotrophin-3 is involved in spinal cord plasticity and regeneration, and that it promotes axonal sprouting from the dorsal root ganglia after spinal cord dorsal root rhizotomy.

Midbrain and medullary control of postinspiratory activity of the crural and costal diaphragm in vivo

NARCIS (Netherlands)

Subramanian, Hari H.; Holstege, Gert

Subramanian HH, Holstege G. Midbrain and medullary control of postinspiratory activity of the crural and costal diaphragm in vivo. J Neurophysiol 105: 2852-2862, 2011. First published March 30, 2011; doi:10.1152/jn.00168.2011.-Studies on brain stem respiratory neurons suggest that eupnea consists of

Effects of obesogenic diet and estradiol on dorsal raphe gene expression in old female macaques.

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Cynthia L Bethea

Full Text Available The beneficial effects of bioidentical ovarian steroid hormone therapy (HT during the perimenopause are gaining recognition. However, the positive effects of estrogen (E plus or minus progesterone (P administration to ovariectomized (Ovx lab animals were recognized in multiple systems for years before clinical trials could adequately duplicate the results. Moreover, very large numbers of women are often needed to find statistically significant results in clinical trials of HT; and there are still opposing results being published, especially in neural and cardiovascular systems. One of the obvious differences between human and animal studies is diet. Laboratory animals are fed a diet that is low in fat and refined sugar, but high in micronutrients. In the US, a large portion of the population eats what is known as a "western style diet" or WSD that provides calories from 36% fat, 44% carbohydrates (includes 18.5% sugars and 18% protein. Unfortunately, obesity and diabetes have reached epidemic proportions and the percentage of obese women in clinical trials may be overlooked. We questioned whether WSD and obesity could decrease the positive neural effects of estradiol (E in the serotonin system of old macaques that were surgically menopausal. Old ovo-hysterectomized female monkeys were fed WSD for 2.5 years, and treated with placebo, Immediate E (ImE or Delayed E (DE. Compared to old Ovx macaques on primate chow and treated with placebo or E, the WSD-fed monkeys exhibited greater individual variance and blunted responses to E-treatment in the expression of genes related to serotonin neurotransmission, CRH components in the midbrain, synapse assembly, DNA repair, protein folding, ubiquitylation, transport and neurodegeneration. For many of the genes examined, transcript abundance was lower in WSD-fed than chow-fed monkeys. In summary, an obesogenic diet for 2.5 years in old surgically menopausal macaques blunted or increased variability in E

Electrophysiological and gene expression characterization of the ontogeny of nestin-expressing cells in the adult mouse midbrain

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Anupama Dey

2017-08-01

Full Text Available The birth of new neurons, or neurogenesis, in the adult midbrain is important for progressing dopamine cell-replacement therapies for Parkinson's disease. Most studies suggest newborn cells remain undifferentiated or differentiate into glia within the adult midbrain. However, some studies suggest nestin + neural precursor cells (NPCs have a propensity to generate new neurons here. We sought to confirm this by administering tamoxifen to adult NesCreERT2/R26eYFP transgenic mice, which permanently labelled adult nestin-expressing cells and their progeny with enhanced yellow fluorescent protein (eYFP. eYFP+ midbrain cells were then characterized 1–32 weeks later in acutely prepared brain slices using whole-cell patch clamp electrophysiology combined with single-cell RT-qPCR. Most eYFP+ cells exhibited a mature neuronal phenotype with large amplitude fast action potentials (APs, spontaneous post-synaptic currents (sPSCs, and expression of ‘mature’ neuronal genes (NeuN, Gad1, Gad2 and/or VGLUT2. This was the case even at the earliest time-point following tamoxifen (i.e. 1 week. In comparison to neighboring eYFP− (control cells, eYFP+ cells discharged more APs per unit current injection, and had faster AP time-to-peak, hyperpolarized resting membrane potential, smaller membrane capacitance and shorter duration sPSCs. eYFP+ cells were also differentiated from eYFP− cells by increased expression of ‘immature’ pro-neuronal genes (Pax6, Ngn2 and/or Msx1. However, further analyses failed to reveal evidence of a place of birth, neuronal differentiation, maturation and integration indicative of classical neurogenesis. Thus our findings do not support the notion that nestin + NPCs in the adult SNc and midbrain generate new neurons via classical neurogenesis. Rather, they raise the possibility that mature neurons express nestin under unknown circumstances, and that this is associated with altered physiology and gene expression.

Activation of substantia gelatinosa by midbrain reticular stimulation demonstrated with 2-deoxyglucose in the rat spinal cord

International Nuclear Information System (INIS)

Gonzales-Lima, F.

1986-01-01

The autoradiographic ( 14 C)2-deoxyglucose (2-DG) method was used to map the descending effects of midbrain reticular stimulation on the rat cervical spinal cord. The stimulation evoked consistently a defensive 'freezing' reaction as well as a large and highly localized increase in 2-DG uptake in the substantia gelatinosa (SG)(Rexed laminae 2-3). No stimulus-induced changes in 2-DG uptake were produced in the other regions of the spinal cord. The findings represent the first anatomical demonstration of the activating effects of the spinal cord. The findings represent the first anatomical demonstration of the activating effects of midbrain reticular stimulation on the spinal cord. They also support the concept of an integrative role for the SG in descending reticular mechanisms at the spinal cord level. (author)

Activation of substantia gelatinosa by midbrain reticular stimulation demonstrated with 2-deoxyglucose in the rat spinal cord

Energy Technology Data Exchange (ETDEWEB)

Gonzales-Lima, F

1986-04-24

The autoradiographic (/sup 14/C)2-deoxyglucose (2-DG) method was used to map the descending effects of midbrain reticular stimulation on the rat cervical spinal cord. The stimulation evoked consistently a defensive 'freezing' reaction as well as a large and highly localized increase in 2-DG uptake in the substantia gelatinosa (SG)(Rexed laminae 2-3). No stimulus-induced changes in 2-DG uptake were produced in the other regions of the spinal cord. The findings represent the first anatomical demonstration of the activating effects of the spinal cord. The findings represent the first anatomical demonstration of the activating effects of midbrain reticular stimulation on the spinal cord. They also support the concept of an integrative role for the SG in descending reticular mechanisms at the spinal cord level. 12 refs.

Optogenetic activation of dorsal raphe serotonin neurons enhances patience for future rewards.

Science.gov (United States)

Miyazaki, Kayoko W; Miyazaki, Katsuhiko; Tanaka, Kenji F; Yamanaka, Akihiro; Takahashi, Aki; Tabuchi, Sawako; Doya, Kenji

2014-09-08

Serotonin is a neuromodulator that is involved extensively in behavioral, affective, and cognitive functions in the brain. Previous recording studies of the midbrain dorsal raphe nucleus (DRN) revealed that the activation of putative serotonin neurons correlates with the levels of behavioral arousal [1], rhythmic motor outputs [2], salient sensory stimuli [3-6], reward, and conditioned cues [5-8]. The classic theory on serotonin states that it opposes dopamine and inhibits behaviors when aversive events are predicted [9-14]. However, the therapeutic effects of serotonin signal-enhancing medications have been difficult to reconcile with this theory [15, 16]. In contrast, a more recent theory states that serotonin facilitates long-term optimal behaviors and suppresses impulsive behaviors [17-21]. To test these theories, we developed optogenetic mice that selectively express channelrhodopsin in serotonin neurons and tested how the activation of serotonergic neurons in the DRN affects animal behavior during a delayed reward task. The activation of serotonin neurons reduced the premature cessation of waiting for conditioned cues and food rewards. In reward omission trials, serotonin neuron stimulation prolonged the time animals spent waiting. This effect was observed specifically when the animal was engaged in deciding whether to keep waiting and was not due to motor inhibition. Control experiments showed that the prolonged waiting times observed with optogenetic stimulation were not due to behavioral inhibition or the reinforcing effects of serotonergic activation. These results show, for the first time, that the timed activation of serotonin neurons during waiting promotes animals' patience to wait for a delayed reward. Copyright © 2014 Elsevier Ltd. All rights reserved.

Air pollution & the brain: Subchronic diesel exhaust exposure causes neuroinflammation and elevates early markers of neurodegenerative disease.

Science.gov (United States)

Levesque, Shannon; Surace, Michael J; McDonald, Jacob; Block, Michelle L

2011-08-24

Increasing evidence links diverse forms of air pollution to neuroinflammation and neuropathology in both human and animal models, but the effects of long-term exposures are poorly understood. We explored the central nervous system consequences of subchronic exposure to diesel exhaust (DE) and addressed the minimum levels necessary to elicit neuroinflammation and markers of early neuropathology. Male Fischer 344 rats were exposed to DE (992, 311, 100, 35 and 0 μg PM/m³) by inhalation over 6 months. DE exposure resulted in elevated levels of TNFα at high concentrations in all regions tested, with the exception of the cerebellum. The midbrain region was the most sensitive, where exposures as low as 100 μg PM/m³ significantly increased brain TNFα levels. However, this sensitivity to DE was not conferred to all markers of neuroinflammation, as the midbrain showed no increase in IL-6 expression at any concentration tested, an increase in IL-1β at only high concentrations, and a decrease in MIP-1α expression, supporting that compensatory mechanisms may occur with subchronic exposure. Aβ42 levels were the highest in the frontal lobe of mice exposed to 992 μg PM/m³ and tau [pS199] levels were elevated at the higher DE concentrations (992 and 311 μg PM/m³) in both the temporal lobe and frontal lobe, indicating that proteins linked to preclinical Alzheimer's disease were affected. α Synuclein levels were elevated in the midbrain in response to the 992 μg PM/m³ exposure, supporting that air pollution may be associated with early Parkinson's disease-like pathology. Together, the data support that the midbrain may be more sensitive to the neuroinflammatory effects of subchronic air pollution exposure. However, the DE-induced elevation of proteins associated with neurodegenerative diseases was limited to only the higher exposures, suggesting that air pollution-induced neuroinflammation may precede preclinical markers of neurodegenerative disease in the midbrain.

Air pollution & the brain: Subchronic diesel exhaust exposure causes neuroinflammation and elevates early markers of neurodegenerative disease

Directory of Open Access Journals (Sweden)

McDonald Jacob

2011-08-01

Full Text Available Abstract Background Increasing evidence links diverse forms of air pollution to neuroinflammation and neuropathology in both human and animal models, but the effects of long-term exposures are poorly understood. Objective We explored the central nervous system consequences of subchronic exposure to diesel exhaust (DE and addressed the minimum levels necessary to elicit neuroinflammation and markers of early neuropathology. Methods Male Fischer 344 rats were exposed to DE (992, 311, 100, 35 and 0 μg PM/m3 by inhalation over 6 months. Results DE exposure resulted in elevated levels of TNFα at high concentrations in all regions tested, with the exception of the cerebellum. The midbrain region was the most sensitive, where exposures as low as 100 μg PM/m3 significantly increased brain TNFα levels. However, this sensitivity to DE was not conferred to all markers of neuroinflammation, as the midbrain showed no increase in IL-6 expression at any concentration tested, an increase in IL-1β at only high concentrations, and a decrease in MIP-1α expression, supporting that compensatory mechanisms may occur with subchronic exposure. Aβ42 levels were the highest in the frontal lobe of mice exposed to 992 μg PM/m3 and tau [pS199] levels were elevated at the higher DE concentrations (992 and 311 μg PM/m3 in both the temporal lobe and frontal lobe, indicating that proteins linked to preclinical Alzheimer's disease were affected. α Synuclein levels were elevated in the midbrain in response to the 992 μg PM/m3 exposure, supporting that air pollution may be associated with early Parkinson's disease-like pathology. Conclusions Together, the data support that the midbrain may be more sensitive to the neuroinflammatory effects of subchronic air pollution exposure. However, the DE-induced elevation of proteins associated with neurodegenerative diseases was limited to only the higher exposures, suggesting that air pollution-induced neuroinflammation may

Tiam1 Regulates the Wnt/Dvl/Rac1 Signaling Pathway and the Differentiation of Midbrain Dopaminergic Neurons

Science.gov (United States)

Čajánek, Lukáš; Ganji, Ranjani Sri; Henriques-Oliveira, Catarina; Theofilopoulos, Spyridon; Koník, Peter

2013-01-01

Understanding the mechanisms that drive the differentiation of dopaminergic (DA) neurons is crucial for successful development of novel therapies for Parkinson's disease, in which DA neurons progressively degenerate. However, the mechanisms underlying the differentiation-promoting effects of Wnt5a on DA precursors are poorly understood. Here, we present the molecular and functional characterization of a signaling pathway downstream of Wnt5a, the Wnt/Dvl/Rac1 pathway. First, we characterize the interaction between Rac1 and Dvl and identify the N-terminal part of Dvl3 as necessary for Rac1 binding. Next, we show that Tiam1, a Rac1 guanosine exchange factor (GEF), is expressed in the ventral midbrain, interacts with Dvl, facilitates Dvl-Rac1 interaction, and is required for Dvl- or Wnt5a-induced activation of Rac1. Moreover, we show that Wnt5a promotes whereas casein kinase 1 (CK1), a negative regulator of the Wnt/Dvl/Rac1 pathway, abolishes the interactions between Dvl and Tiam1. Finally, using ventral midbrain neurosphere cultures, we demonstrate that the generation of DA neurons in culture is impaired after Tiam1 knockdown, indicating that Tiam1 is required for midbrain DA differentiation. In summary, our data identify Tiam1 as a novel regulator of DA neuron development and as a Dvl-associated and Rac1-specific GEF acting in the Wnt/Dvl/Rac1 pathway. PMID:23109420

Re-thinking the role of the dorsal striatum in egocentric/response strategy.

Science.gov (United States)

Botreau, Fanny; Gisquet-Verrier, Pascale

2010-01-01

Rats trained in a dual-solution cross-maze task, which can be solved by place and response strategies, predominantly used a response strategy after extensive training. This paper examines the involvement of the medial and lateral dorsal striatum (mDS and lDS) in the choice of these strategies after partial and extensive training. Our results show that rats with lDS and mDS lesions used mainly a response strategy from the early phase of training. We replicated these unexpected data in rats with lDS lesions and confirmed their tendency to use the response strategy in a modified cross-maze task. When trained in a dual-solution water-maze task, however, control and lesioned rats consistently used a place strategy, demonstrating that lDS and mDS lesioned rats can use a place strategy and that the shift towards a response strategy did not systematically result from extensive training. The present data did not show any clear dissociation between the mDS and lDS in dual solution tasks. They further indicate that the dorsal striatum seems to determine the strategies adopted in a particular context but cannot be considered as a neural support for the response memory system. Accordingly, the role of the lateral and medial part of the dorsal striatum in egocentric/response memory should be reconsidered.

Music exposure improves spatial cognition by enhancing the BDNF level of dorsal hippocampal subregions in the developing rats.

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Xing, Yingshou; Chen, Wenxi; Wang, Yanran; Jing, Wei; Gao, Shan; Guo, Daqing; Xia, Yang; Yao, Dezhong

2016-03-01

Previous research has shown that dorsal hippocampus plays an important role in spatial memory process. Music exposure can enhance brain-derived neurotrophic factor (BDNF) expression level in dorsal hippocampus (DH) and thus enhance spatial cognition ability. But whether music experience may affect different subregions of DH in the same degree remains unclear. Here, we studied the effects of exposure to Mozart K.448 on learning behavior in developing rats using the classical Morris water maze task. The results showed that early music exposure could enhance significantly learning performance of the rats in the water maze test. Meanwhile, the BDNF/TrkB level of dorsal hippocampus CA3 (dCA3) and dentate gyrus (dDG) was significantly enhanced in rats exposed to Mozart music as compared to those without music exposure. In contrast, the BDNF/TrkB level of dorsal hippocampus CA1 (dCA1) was not affected. The results suggest that the spatial memory improvement by music exposure in rats may be associated with the enhanced BDNF/TrkB level of dCA3 and dDG. Copyright © 2016 Elsevier Inc. All rights reserved.

Wernekink Commissure Syndrome Secondary to Bilateral Caudal Paramedian Midbrain Infarction Presenting with a Unique “Heart or V” Appearance Sign: Case Report and Review of the Literature

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Chenguang Zhou

2017-08-01

Full Text Available Wernekink commissure syndrome secondary to caudal paramedian midbrain infarction (CPMI is a rare midbrain syndrome involving the decussation of the superior cerebellar peduncle in the caudal paramedian midbrain tegmentum. The central characteristics are constant bilateral cerebellar dysfunction, variable eye movement disorders, and rare delayed palatal myoclonus. Following is a description of the case of a 60-year-old man who presented with dizziness, slurred speech, and difficulty walking. Neurological examination revealed bilateral cerebellar dysfunction and bilateral internuclear ophthalmoplegia (bilateral INO. Serial magnetic resonance imaging (MRI revealed a lesion in the caudal paramedian midbrain with a “heart-shaped” sign on fluid-attenuation inversion recovery images and a “V-shaped” appearance on diffusion-weighted imaging (DWI. An acute CPMI with a “heart or V” appearance sign was diagnosed. Upon follow-up evaluation 3 months later, a palatal tremor accompanied by involuntary head tremor was discovered. Hypertrophy and increased signal of the bilateral inferior olivary nucleus, compatible with hypertropic olivary degeneration (HOD were revealed during a subsequent MRI study.

Chronic Stress Triggers Expression of Immediate Early Genes and Differentially Affects the Expression of AMPA and NMDA Subunits in Dorsal and Ventral Hippocampus of Rats

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Anibal Pacheco

2017-08-01

Full Text Available Previous studies in rats have demonstrated that chronic restraint stress triggers anhedonia, depressive-like behaviors, anxiety and a reduction in dendritic spine density in hippocampal neurons. In this study, we compared the effect of repeated stress on the expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA and N-methyl-D-aspartate (NMDA receptor subunits in dorsal and ventral hippocampus (VH. Adult male Sprague-Dawley rats were randomly divided into control and stressed groups, and were daily restrained in their motion (2.5 h/day during 14 days. We found that chronic stress promotes an increase in c-Fos mRNA levels in both hippocampal areas, although it was observed a reduction in the immunoreactivity at pyramidal cell layer. Furthermore, Arc mRNAs levels were increased in both dorsal and VH, accompanied by an increase in Arc immunoreactivity in dendritic hippocampal layers. Furthermore, stress triggered a reduction in PSD-95 and NR1 protein levels in whole extract of dorsal and VH. Moreover, a reduction in NR2A/NR2B ratio was observed only in dorsal pole. In synaptosomal fractions, we detected a rise in NR1 in dorsal hippocampus (DH. By indirect immunofluorescence we found that NR1 subunits rise, especially in neuropil areas of dorsal, but not VH. In relation to AMPA receptor (AMPAR subunits, chronic stress did not trigger any change, either in dorsal or ventral hippocampal areas. These data suggest that DH is more sensitive than VH to chronic stress exposure, mainly altering the expression of NMDA receptor (NMDAR subunits, and probably favors changes in the configuration of this receptor that may influence the function of this area.

Tualang Honey Protects the Rat Midbrain and Lung against Repeated Paraquat Exposure

OpenAIRE

Tang, Suk Peng; Kuttulebbai Nainamohamed Salam, Sirajudeen; Jaafar, Hasnan; Gan, Siew Hua; Muzaimi, Mustapha; Sulaiman, Siti Amrah

2017-01-01

Paraquat (PQ) is a dopaminergic neurotoxin and a well-known pneumotoxicant that exerts its toxic effect via oxidative stress-mediated cellular injuries. This study investigated the protective effects of Tualang honey against PQ-induced toxicity in the midbrain and lungs of rats. The rats were orally treated with distilled water (2?mL/kg/day), Tualang honey (1.0?g/kg/day), or ubiquinol (0.2?g/kg/day) throughout the experimental period. Two weeks after the respective treatments, the rats were i...

Increased Fos expression among midbrain dopaminergic cell groups during birdsong tutoring.

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Nordeen, E J; Holtzman, D A; Nordeen, K W

2009-08-01

During avian vocal learning, birds memorize conspecific song patterns and then use auditory feedback to match their vocal output to this acquired template. Some models of song learning posit that during tutoring, conspecific visual, social and/or auditory cues activate neuromodulatory systems that encourage acquisition of the tutor's song and attach incentive value to that specific acoustic pattern. This hypothesis predicts that stimuli experienced during social tutoring activate cell populations capable of signaling reward. Using immunocytochemistry for the protein product of the immediate early gene c-Fos, we found that brief exposure of juvenile male zebra finches to a live familiar male tutor increased the density of Fos+ cells within two brain regions implicated in reward processing: the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc). This activation of Fos appears to involve both dopaminergic and non-dopaminergic VTA/SNc neurons. Intriguingly, a familiar tutor was more effective than a novel tutor in stimulating Fos expression within these regions. In the periaqueductal gray, a dopamine-enriched cell population that has been implicated in emotional processing, Fos labeling also was increased after tutoring, with a familiar tutor again being more effective than a novel conspecific. As several neural regions implicated in song acquisition receive strong dopaminergic projections from these midbrain nuclei, their activation in conjunction with hearing the tutor's song could help to establish sensory representations that later guide motor sequence learning.

CRISPR/Cas9-Mediated Zebrafish Knock-in as a Novel Strategy to Study Midbrain-Hindbrain Boundary Development.

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Kesavan, Gokul; Chekuru, Avinash; Machate, Anja; Brand, Michael

2017-01-01

The midbrain-hindbrain boundary (MHB) acts as an organizer and controls the fate of neighboring cells to develop into either mesencephalic (midbrain) or metencephalic (hindbrain) cells by secreting signaling molecules like Wnt1 and Fgf8. The zebrafish is an excellent vertebrate model for studying MHB development due to the ease of gene manipulation and the possibility of following cellular dynamics and morphogenetic processes using live imaging. Currently, only very few reporter and/or Cre-driver lines are available to study gene expression at the MHB, hampering the understanding of MHB development, and traditional transgenic technologies using promoter/enhancer fragments or bacterial artificial chromosome (BAC)-mediated transgenesis often do not faithfully recapitulate endogenous expression patterns. In contrast, CRISPR/Cas9-mediated genome editing technology now provides a great opportunity to efficiently knock-in or knock-out genes. We have generated four CRISPR/Cas9-based knock-in fluorescent reporter lines for two crucial genes involved in MHB development, namely otx2 and pax2a . The coding sequences of the reporters were knocked-in upstream of the corresponding ATG and are, thus, under the control of the endogenous promoter/enhancer elements. Interestingly, this strategy does not disturb endogenous gene expression. Using the fast maturing fluorescent protein reporter, Venus, enabled us to follow MHB development using cell tracking and live imaging. In addition, we show that these reporter lines label various neuronal and glial cell types in the adult zebrafish brain, making them highly suitable for investigating embryonic and adult midbrain, hindbrain, and MHB development.

FoxA4 favours notochord formation by inhibiting contiguous mesodermal fates and restricts anterior neural development in Xenopus embryos.

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Sabrina Murgan

Full Text Available In vertebrates, the embryonic dorsal midline is a crucial signalling centre that patterns the surrounding tissues during development. Members of the FoxA subfamily of transcription factors are expressed in the structures that compose this centre. Foxa2 is essential for dorsal midline development in mammals, since knock-out mouse embryos lack a definitive node, notochord and floor plate. The related gene foxA4 is only present in amphibians. Expression begins in the blastula -chordin and -noggin expressing centre (BCNE and is later restricted to the dorsal midline derivatives of the Spemann's organiser. It was suggested that the early functions of mammalian foxa2 are carried out by foxA4 in frogs, but functional experiments were needed to test this hypothesis. Here, we show that some important dorsal midline functions of mammalian foxa2 are exerted by foxA4 in Xenopus. We provide new evidence that the latter prevents the respecification of dorsal midline precursors towards contiguous fates, inhibiting prechordal and paraxial mesoderm development in favour of the notochord. In addition, we show that foxA4 is required for the correct regionalisation and maintenance of the central nervous system. FoxA4 participates in constraining the prospective rostral forebrain territory during neural specification and is necessary for the correct segregation of the most anterior ectodermal derivatives, such as the cement gland and the pituitary anlagen. Moreover, the early expression of foxA4 in the BCNE (which contains precursors of the whole forebrain and most of the midbrain and hindbrain is directly required to restrict anterior neural development.

Safety and tolerability of MRI-guided infusion of AAV2-hAADC into the mid-brain of nonhuman primate

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Waldy San Sebastian

2014-01-01

Full Text Available Aromatic L-amino acid decarboxylase (AADC deficiency is a rare, autosomal-recessive neurological disorder caused by mutations in the DDC gene that leads to an inability to synthesize catecholamines and serotonin. As a result, patients suffer compromised development, particularly in motor function. A recent gene replacement clinical trial explored putaminal delivery of recombinant adeno-associated virus serotype 2 vector encoding human AADC (AAV2-hAADC in AADC-deficient children. Unfortunately, patients presented only modest amelioration of motor symptoms, which authors acknowledged could be due to insufficient transduction of putamen. We hypothesize that, with the development of a highly accurate MRI-guided cannula placement technology, a more effective approach might be to target the affected mid-brain neurons directly. Transduction of AADC-deficient dopaminergic neurons in the substantia nigra and ventral tegmental area with locally infused AAV2-hAADC would be expected to lead to restoration of normal dopamine levels in affected children. The objective of this study was to assess the long-term safety and tolerability of bilateral AAV2-hAADC MRI-guided pressurized infusion into the mid-brain of nonhuman primates. Animals received either vehicle, low or high AAV2-hAADC vector dose and were euthanized 1, 3, or 9 months after surgery. Our data indicate that effective mid-brain transduction was achieved without untoward effects.

The dorsal striatum and ventral striatum play different roles in the programming of social behaviour: a tribute to Lex Cools.

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van den Bos, Ruud

2015-02-01

Early work by Lex Cools suggested that the caudate nucleus (dorsal striatum) plays a role in programming social behaviour: enhanced activity in the caudate nucleus increased the extent to which ongoing behaviour is controlled by the individual's own behaviour (internal control) rather than by that of its partners (external control). Interestingly, later studies by others have indicated that the ventral striatum plays a role in external rather than internal control. Here, I discuss the role of these different striatal areas - and the emotional (ventral striatum) and cognitive control (dorsal striatum) system in which they are embedded - in the organization of social behaviour in the context of locus of control. Following on from this discussion, I will pay particular attention to individual differences in social behaviour (individuals with more internal or external control), focusing on the role of dopamine, serotonin and the effects of stress-related challenges in relation to their different position in a dominance hierarchy. I will subsequently allude to potential psychological and behavioural problems in the social domain following on from these differences in locus of control ['social obliviousness' (dorsal stratum) and 'social impulsivity' (ventral striatum)]. In doing so, I provide as a tribute a historical account of the early research by Lex Cools.

Dorsal finger texture recognition: Investigating fixed-length SURF

DEFF Research Database (Denmark)

Hartung, Daniel; Kückelhahn, Jesper

2012-01-01

We seek to create fixed-length features from dorsal finger skin images extracted by the SURF interest point detector to combine it in the privacy enhancing helper data scheme. The source of the biometric samples is the GUC45 database which features finger vein, fingerprint and dorsal finger skin...

Glutamate neurons are intermixed with midbrain dopamine neurons in nonhuman primates and humans

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Root, David H.; Wang, Hui-Ling; Liu, Bing; Barker, David J.; Mód, László; Szocsics, Péter; Silva, Afonso C.; Maglóczky, Zsófia; Morales, Marisela

2016-01-01

The rodent ventral tegmental area (VTA) and substantia nigra pars compacta (SNC) contain dopamine neurons intermixed with glutamate neurons (expressing vesicular glutamate transporter 2; VGluT2), which play roles in reward and aversion. However, identifying the neuronal compositions of the VTA and SNC in higher mammals has remained challenging. Here, we revealed VGluT2 neurons within the VTA and SNC of nonhuman primates and humans by simultaneous detection of VGluT2 mRNA and tyrosine hydroxylase (TH; for identification of dopamine neurons). We found that several VTA subdivisions share similar cellular compositions in nonhuman primates and humans; their rostral linear nuclei have a high prevalence of VGluT2 neurons lacking TH; their paranigral and parabrachial pigmented nuclei have mostly TH neurons, and their parabrachial pigmented nuclei have dual VGluT2-TH neurons. Within nonhuman primates and humans SNC, the vast majority of neurons are TH neurons but VGluT2 neurons were detected in the pars lateralis subdivision. The demonstration that midbrain dopamine neurons are intermixed with glutamate or glutamate-dopamine neurons from rodents to humans offers new opportunities for translational studies towards analyzing the roles that each of these neurons play in human behavior and in midbrain-associated illnesses such as addiction, depression, schizophrenia, and Parkinson’s disease. PMID:27477243

MicroRNA-326 acts as a molecular switch in the regulation of midbrain urocortin 1 expression

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Aschrafi, Armaz; Verheijen, Jan M.; Gordebeke, Peter M.; Olde Loohuis, Nikkie F.; Menting, Kelly; Jager, Amanda; Palkovits, Miklos; Geenen, Bram; Kos, Aron; Martens, Gerard J.M.; Glennon, Jeffrey C.; Kaplan, Barry B.; Gaszner, Balázs; Kozicz, Tamas

2016-01-01

Background Altered levels of urocortin 1 (Ucn1) in the centrally projecting Edinger–Westphal nucleus (EWcp) of depressed suicide attempters or completers mediate the brain’s response to stress, while the mechanism regulating Ucn1 expression is unknown. We tested the hypothesis that microRNAs (miRNAs), which are vital fine-tuners of gene expression during the brain’s response to stress, have the capacity to modulate Ucn1 expression. Methods Computational analysis revealed that the Ucn1 3′ untranslated region contained a conserved binding site for miR-326. We examined miR-326 and Ucn1 levels in the EWcp of depressed suicide completers. In addition, we evaluated miR-326 and Ucn1 levels in the serum and the EWcp of a chronic variable mild stress (CVMS) rat model of behavioural despair and after recovery from CVMS, respectively. Gain and loss of miR-326 function experiments examined the regulation of Ucn1 by this miRNA in cultured midbrain neurons. Results We found reduced miR-326 levels concomitant with elevated Ucn1 levels in the EWcp of depressed suicide completers as well as in the EWcp of CVMS rats. In CVMS rats fully recovered from stress, both serum and EWcp miR-326 levels rebounded to nonstressed levels. While downregulation of miR-326 levels in primary midbrain neurons enhanced Ucn1 expression levels, miR-326 overexpression selectively reduced the levels of this neuropeptide. Limitations This study lacked experiments showing that in vivo alteration of miR-326 levels alleviate depression-like behaviours. We show only correlative data for miR-325 and cocaine- and amphetamine-regulated transcript levels in the EWcp. Conclusion We identified miR-326 dysregulation in depressed suicide completers and characterized this miRNA as an upstream regulator of the Ucn1 neuropeptide expression in midbrain neurons. PMID:27045550

Midbrain expression of Delta-like 1 homologue is regulated by GDNF and is associated with dopaminergic differentiation

DEFF Research Database (Denmark)

Christophersen, Nicolai S.; Gronborg, Mette; Petersen, Thomas Nordahl

2007-01-01

upregulation with increased positive staining of cell bodies in the SNc and fibers in the striatum. Analysis of the developmental regulation of Dlk1 in the murine ventral midbrain showed that the upregulation of Dlk1 mRNA correlated with the generation of tyrosine hydroxylase (TH)-positive neurons. Furthermore...

Spumiform basement membrane aberrations in the microvasculature of the midbrain periaqueductal gray region in hamster : Rostro-caudal pathogenesis?

NARCIS (Netherlands)

Gerrits, P.O.; Kortekaas, R.; de Weerd, Heleen; Luiten, P.G.M.; van der Want, J.J.L.; Veening, Jan

2013-01-01

Spumiform basement membrane degeneration (sbmd) is a specific kind of aberration present in the capillaries of the midbrain periaqueductal gray (PAG) region of the senescent hamster. These capillaries, separated by the ependymal cell layer, are bordering the Sylvian cerebral aqueduct. The aqueduct,

Spumiform basement membrane aberrations in the microvasculature of the midbrain periaqueductal gray region in hamster: rostro-caudal pathogenesis?

NARCIS (Netherlands)

Gerrits, P.O.; Kortekaas, R.; Weerd, H. de; Luiten, P.G.M.; Want, J.J. van der; Veening, J.G.

2013-01-01

Spumiform basement membrane degeneration (sbmd) is a specific kind of aberration present in the capillaries of the midbrain periaqueductal gray (PAG) region of the senescent hamster. These capillaries, separated by the ependymal cell layer, are bordering the Sylvian cerebral aqueduct. The aqueduct,

Functional connectivity of the dorsal striatum in female musicians

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Shoji eTanaka

2016-04-01

Full Text Available The dorsal striatum (caudate/putamen is a node of the cortico-striato-pallido-thalamo-cortical (CSPTC motor circuit, which plays a central role in skilled motor learning, a critical feature of musical performance. The dorsal striatum receives input from a large part of the cerebral cortex, forming a hub in the cortical-subcortical network. This study sought to examine how the functional network of the dorsal striatum differs between musicians and nonmusicians.Resting state functional magnetic resonance imaging (fMRI data were acquired from female university students majoring in music and nonmusic disciplines. The data were subjected to graph theoretical analysis and functional connectivity analysis. The graph theoretical analysis of the entire brain revealed that the degree, which represents the number of connections, of the bilateral putamen was significantly lower in musicians than in nonmusicians. The functional connectivity analysis indicated that compared with nonmusicians, musicians had significantly decreased connectivity between the left putamen and bilateral frontal operculum and between the left caudate nucleus and cerebellum. In conclusion, compared with nonmusicians, female musicians have a smaller functional network of the dorsal striatum, with decreased connectivity. These data are consistent with previous anatomical studies reporting a reduced volume of the dorsal striatum in musicians and ballet dancers. To the best of our knowledge, this is the first study suggesting that long-term musical training results in a less extensive or selective functional network of the dorsal striatum.

The Maternal Maverick/GDF15-like TGF-β Ligand Panda Directs Dorsal-Ventral Axis Formation by Restricting Nodal Expression in the Sea Urchin Embryo

Science.gov (United States)

Haillot, Emmanuel; Molina, Maria Dolores; Lapraz, François; Lepage, Thierry

2015-01-01

Specification of the dorsal-ventral axis in the highly regulative sea urchin embryo critically relies on the zygotic expression of nodal, but whether maternal factors provide the initial spatial cue to orient this axis is not known. Although redox gradients have been proposed to entrain the dorsal-ventral axis by acting upstream of nodal, manipulating the activity of redox gradients only has modest consequences, suggesting that other factors are responsible for orienting nodal expression and defining the dorsal-ventral axis. Here we uncover the function of Panda, a maternally provided transforming growth factor beta (TGF-β) ligand that requires the activin receptor-like kinases (Alk) Alk3/6 and Alk1/2 receptors to break the radial symmetry of the embryo and orient the dorsal-ventral axis by restricting nodal expression. We found that the double inhibition of the bone morphogenetic protein (BMP) type I receptors Alk3/6 and Alk1/2 causes a phenotype dramatically more severe than the BMP2/4 loss-of-function phenotype, leading to extreme ventralization of the embryo through massive ectopic expression of nodal, suggesting that an unidentified signal acting through BMP type I receptors cooperates with BMP2/4 to restrict nodal expression. We identified this ligand as the product of maternal Panda mRNA. Double inactivation of panda and bmp2/4 led to extreme ventralization, mimicking the phenotype caused by inactivation of the two BMP receptors. Inhibition of maternal panda mRNA translation disrupted the early spatial restriction of nodal, leading to persistent massive ectopic expression of nodal on the dorsal side despite the presence of Lefty. Phylogenetic analysis indicates that Panda is not a prototypical BMP ligand but a member of a subfamily of TGF-β distantly related to Inhibins, Lefty, and TGF-β that includes Maverick from Drosophila and GDF15 from vertebrates. Indeed, overexpression of Panda does not appear to directly or strongly activate phosphoSmad1

The Maternal Maverick/GDF15-like TGF-β Ligand Panda Directs Dorsal-Ventral Axis Formation by Restricting Nodal Expression in the Sea Urchin Embryo.

Science.gov (United States)

Haillot, Emmanuel; Molina, Maria Dolores; Lapraz, François; Lepage, Thierry

2015-01-01

Specification of the dorsal-ventral axis in the highly regulative sea urchin embryo critically relies on the zygotic expression of nodal, but whether maternal factors provide the initial spatial cue to orient this axis is not known. Although redox gradients have been proposed to entrain the dorsal-ventral axis by acting upstream of nodal, manipulating the activity of redox gradients only has modest consequences, suggesting that other factors are responsible for orienting nodal expression and defining the dorsal-ventral axis. Here we uncover the function of Panda, a maternally provided transforming growth factor beta (TGF-β) ligand that requires the activin receptor-like kinases (Alk) Alk3/6 and Alk1/2 receptors to break the radial symmetry of the embryo and orient the dorsal-ventral axis by restricting nodal expression. We found that the double inhibition of the bone morphogenetic protein (BMP) type I receptors Alk3/6 and Alk1/2 causes a phenotype dramatically more severe than the BMP2/4 loss-of-function phenotype, leading to extreme ventralization of the embryo through massive ectopic expression of nodal, suggesting that an unidentified signal acting through BMP type I receptors cooperates with BMP2/4 to restrict nodal expression. We identified this ligand as the product of maternal Panda mRNA. Double inactivation of panda and bmp2/4 led to extreme ventralization, mimicking the phenotype caused by inactivation of the two BMP receptors. Inhibition of maternal panda mRNA translation disrupted the early spatial restriction of nodal, leading to persistent massive ectopic expression of nodal on the dorsal side despite the presence of Lefty. Phylogenetic analysis indicates that Panda is not a prototypical BMP ligand but a member of a subfamily of TGF-β distantly related to Inhibins, Lefty, and TGF-β that includes Maverick from Drosophila and GDF15 from vertebrates. Indeed, overexpression of Panda does not appear to directly or strongly activate phosphoSmad1

Wnt5a regulates ventral midbrain morphogenesis and the development of A9-A10 dopaminergic cells in vivo

Czech Academy of Sciences Publication Activity Database

Andersson, E.R.; Prakash, N.; Čajánek, L.; Minina, E.; Bryja, Vítězslav; Bryjová, Lenka; Yamaguchi, T.P.; Hall, A.C.; Wurst, W.; Arenas, E.

2008-01-01

Roč. 3, č. 10 (2008), s. 1-14 E-ISSN 1932-6203 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Wnt 5a deficient mouse * ventral midbrain * planar cell polarity Subject RIV: BO - Biophysics

Ascending Midbrain Dopaminergic Axons Require Descending GAD65 Axon Fascicles for Normal Pathfinding

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Claudia Marcela Garcia-Peña

2014-06-01

Full Text Available The Nigrostriatal pathway (NSP is formed by dopaminergic axons that project from the ventral midbrain to the dorsolateral striatum as part of the medial forebrain bundle. Previous studies have implicated chemotropic proteins in the formation of the NSP during development but little is known of the role of substrate-anchored signals in this process. We observed in mouse and rat embryos that midbrain dopaminergic axons ascend in close apposition to descending GAD65-positive axon bundles throughout their trajectory to the striatum. To test whether such interaction is important for dopaminergic axon pathfinding, we analyzed transgenic mouse embryos in which the GAD65 axon bundle was reduced by the conditional expression of the diphtheria toxin. In these embryos we observed dopaminergic misprojection into the hypothalamic region and abnormal projection in the striatum. In addition, analysis of Robo1/2 and Slit1/2 knockout embryos revealed that the previously described dopaminergic misprojection in these embryos is accompanied by severe alterations in the GAD65 axon scaffold. Additional studies with cultured dopaminergic neurons and whole embryos suggest that NCAM and Robo proteins are involved in the interaction of GAD65 and dopaminergic axons. These results indicate that the fasciculation between descending GAD65 axon bundles and ascending dopaminergic axons is required for the stereotypical NSP formation during brain development and that known guidance cues may determine this projection indirectly by instructing the pathfinding of the axons that are part of the GAD65 axon scaffold.

Hydrodynamic function of dorsal fins in spiny dogfish and bamboo sharks during steady swimming.

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Maia, Anabela; Lauder, George V; Wilga, Cheryl D

2017-11-01

A key feature of fish functional design is the presence of multiple fins that allow thrust vectoring and redirection of fluid momentum to contribute to both steady swimming and maneuvering. A number of previous studies have analyzed the function of dorsal fins in teleost fishes in this context, but the hydrodynamic function of dorsal fins in freely swimming sharks has not been analyzed, despite the potential for differential functional roles between the anterior and posterior dorsal fins. Previous anatomical research has suggested a primarily stabilizing role for shark dorsal fins. We evaluated the generality of this hypothesis by using time-resolved particle image velocimetry to record water flow patterns in the wake of both the anterior and posterior dorsal fins in two species of freely swimming sharks: bamboo sharks ( Chiloscyllium plagiosum ) and spiny dogfish ( Squalus acanthias ). Cross-correlation analysis of consecutive images was used to calculate stroke-averaged mean longitudinal and lateral velocity components, and vorticity. In spiny dogfish, we observed a velocity deficit in the wake of the first dorsal fin and flow acceleration behind the second dorsal fin, indicating that the first dorsal fin experiences net drag while the second dorsal fin can aid in propulsion. In contrast, the wake of both dorsal fins in bamboo sharks displayed increased net flow velocity in the majority of trials, reflecting a thrust contribution to steady swimming. In bamboo sharks, fluid flow in the wake of the second dorsal fin had higher absolute average velocity than that for first dorsal fin, and this may result from a positive vortex interaction between the first and second dorsal fins. These data suggest that the first dorsal fin in spiny dogfish has primarily a stabilizing function, while the second dorsal fin has a propulsive function. In bamboo sharks, both dorsal fins can contribute thrust and should be considered as propulsive adjuncts to the body during steady

Behavior-driven arc expression is reduced in all ventral hippocampal subfields compared to CA1, CA3, and dentate gyrus in rat dorsal hippocampus.

Science.gov (United States)

Chawla, M K; Sutherland, V L; Olson, K; McNaughton, B L; Barnes, C A

2018-02-01

Anatomical connectivity and lesion studies reveal distinct functional heterogeneity along the dorsal-ventral axis of the hippocampus. The immediate early gene Arc is known to be involved in neural plasticity and memory and can be used as a marker for cell activity that occurs, for example, when hippocampal place cells fire. We report here, that Arc is expressed in a greater proportion of cells in dorsal CA1, CA3, and dentate gyrus (DG), following spatial behavioral experiences compared to ventral hippocampal subregions (dorsal CA1 = 33%; ventral CA1 = 13%; dorsal CA3 = 23%; ventral CA3 = 8%; and dorsal DG = 2.5%; ventral DG = 1.2%). The technique used here to obtain estimates of numbers of behavior-driven cells across the dorsal-ventral axis, however, corresponds quite well with samples from available single unit recording studies. Several explanations for the two- to-threefold reduction in spatial behavior-driven cell activity in the ventral hippocampus can be offered. These include anatomical connectivity differences, differential gain of the self-motion signals that appear to alter the scale of place fields and the proportion of active cells, and possibly variations in the neuronal responses to non-spatial information within the hippocampus along its dorso-ventral axis. © 2017 Wiley Periodicals, Inc.

[Role of the midbrain reticular formation in hormonal supply to the body in conditions of chronic emotional stress].

Science.gov (United States)

Amiragova, M G; Arakhangel'skaia, M I

1983-08-01

Chronic animal experiments were made to study the endocrine and electroencephalographic responses of the cortico-subcortical structures to stress before and after coagulation of the midbrain reticular formation. The operation entailed dramatic changes in both the bioelectrical responses and thyroid and adrenal responses, which were found to be differentiated.

Discrimination of dementia with Lewy bodies from Alzheimer's disease using voxel-based morphometry of white matter by statistical parametric mapping 8 plus diffeomorphic anatomic registration through exponentiated Lie algebra.

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Nakatsuka, Tomoya; Imabayashi, Etsuko; Matsuda, Hiroshi; Sakakibara, Ryuji; Inaoka, Tsutomu; Terada, Hitoshi

2013-05-01

The purpose of this study was to identify brain atrophy specific for dementia with Lewy bodies (DLB) and to evaluate the discriminatory performance of this specific atrophy between DLB and Alzheimer's disease (AD). We retrospectively reviewed 60 DLB and 30 AD patients who had undergone 3D T1-weighted MRI. We randomly divided the DLB patients into two equal groups (A and B). First, we obtained a target volume of interest (VOI) for DLB-specific atrophy using correlation analysis of the percentage rate of significant whole white matter (WM) atrophy calculated using the Voxel-based Specific Regional Analysis System for Alzheimer's Disease (VSRAD) based on statistical parametric mapping 8 (SPM8) plus diffeomorphic anatomic registration through exponentiated Lie algebra, with segmented WM images in group A. We then evaluated the usefulness of this target VOI for discriminating the remaining 30 DLB patients in group B from the 30 AD patients. Z score values in this target VOI obtained from VSRAD were used as the determinant in receiver operating characteristic (ROC) analysis. Specific target VOIs for DLB were determined in the right-side dominant dorsal midbrain, right-side dominant dorsal pons, and bilateral cerebellum. ROC analysis revealed that the target VOI limited to the midbrain exhibited the highest area under the ROC curves of 0.75. DLB patients showed specific atrophy in the midbrain, pons, and cerebellum. Midbrain atrophy demonstrated the highest power for discriminating DLB and AD. This approach may be useful for determining the contributions of DLB and AD pathologies to the dementia syndrome.

α-Synuclein-induced lysosomal dysfunction occurs through disruptions in protein trafficking in human midbrain synucleinopathy models.

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Mazzulli, Joseph R; Zunke, Friederike; Isacson, Ole; Studer, Lorenz; Krainc, Dimitri

2016-02-16

Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized by the accumulation of protein aggregates comprised of α-synuclein (α-syn). A major barrier in treatment discovery for PD is the lack of identifiable therapeutic pathways capable of reducing aggregates in human neuronal model systems. Mutations in key components of protein trafficking and cellular degradation machinery represent important risk factors for PD; however, their precise role in disease progression and interaction with α-syn remains unclear. Here, we find that α-syn accumulation reduced lysosomal degradation capacity in human midbrain dopamine models of synucleinopathies through disrupting hydrolase trafficking. Accumulation of α-syn at the cell body resulted in aberrant association with cis-Golgi-tethering factor GM130 and disrupted the endoplasmic reticulum-Golgi localization of rab1a, a key mediator of vesicular transport. Overexpression of rab1a restored Golgi structure, improved hydrolase trafficking and activity, and reduced pathological α-syn in patient neurons. Our work suggests that enhancement of lysosomal hydrolase trafficking may prove beneficial in synucleinopathies and indicates that human midbrain disease models may be useful for identifying critical therapeutic pathways in PD and related disorders.

The time-course of activation in the dorsal and ventral visual streams during landmark cueing and perceptual discrimination tasks.

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Lambert, Anthony J; Wootton, Adrienne

2017-08-01

Different patterns of high density EEG activity were elicited by the same peripheral stimuli, in the context of Landmark Cueing and Perceptual Discrimination tasks. The C1 component of the visual event-related potential (ERP) at parietal - occipital electrode sites was larger in the Landmark Cueing task, and source localisation suggested greater activation in the superior parietal lobule (SPL) in this task, compared to the Perceptual Discrimination task, indicating stronger early recruitment of the dorsal visual stream. In the Perceptual Discrimination task, source localisation suggested widespread activation of the inferior temporal gyrus (ITG) and fusiform gyrus (FFG), structures associated with the ventral visual stream, during the early phase of the P1 ERP component. Moreover, during a later epoch (171-270ms after stimulus onset) increased temporal-occipital negativity, and stronger recruitment of ITG and FFG were observed in the Perceptual Discrimination task. These findings illuminate the contrasting functions of the dorsal and ventral visual streams, to support rapid shifts of attention in response to contextual landmarks, and conscious discrimination, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Arterial blood supply to midbrain, thalamus and internal capsule on CT, 3

International Nuclear Information System (INIS)

Takeshita, Gen; Ottomo, Michinori; Sasaki, Taisuke; Fukuda, Eiko.

1984-01-01

The selective injection of dye into the anterior choroidal artery (blue), the medial posterior choroidal artery (green), and the lateral posterior choroidal artery (red), using seven post-mortem brains, was performed. After fixation, sections parallel with the orbito-meatal line were obtained. The distribution of the anterior choroidal artery was visualized in the uncal region of the temporal lobe and the cerebral peduncle below the slice of the third ventricle. On the slice of the third ventricle, the lateral part of the geniculate region, the globus pallidus, and the posterior limb of the internal capsule were supplied by the anterior choroidal artery. The blood supply of the posterior limb of the internal capsule was also demonstrated on the slice of the anterior horn and on the body of the lateral ventricle. The distribution of the medial posterior choroidal artery was visualized in the tegmentum of the midbrain below the slice of the third ventricle, and on the slice of the anterior horn, the pineal body and the posterior part of the thalamus were also supplied. The distribution of the lateral posterior choroidal artery was visualized in the lateral part of the midbrain, around the red nucleus, below the slice of the third ventricle, and on the slice of the third ventricle, the upper part of the cerebral peduncle, the posterior part of the hypothalamus, and the medial part of the geniculate region were also supplied. Also, distribution to the medial and posterior parts of the thalamus was noted on the slice of the anterior horn. It was quite useful to identify the distribution of each choroidal artery on CT sections for the CT diagnosis of cerebrovascular disorders. (author)

Periostite metacarpiana dorsal: incidência e fatores pré-disponentes

Directory of Open Access Journals (Sweden)

Flávio Gomes de Oliveira

2006-04-01

Full Text Available Forty two 2-year-old thoroughbreds were examined clinically at intervals of 15 days during their training for the first race to determine the incidence and the predisposing factors of dorsal metacarpal disease. During the first year 25 horses were followed during 2 months and in the second year the follow up was done for 4 months in 17 . Horses' data like gender, average speed, speed exercise work and trainer were also collected. Dorsal metacarpal disease was diagnosed in 28% and 70,6% of the 2 year-old thoroughbreds in the first and second year of the study, respectively. Total incidence was 45%. The incidence and average speed was not affected by gender. The average speed achieved by affected and none affected horses remained between 16 and 18m/s. On 500 and 700m speed exercise, the average speed of affected horses was higher than of none affected ones (p<0,05. Ten out of 19 horses showed dorsal metacarpal disease signs at the distance of 700m. There was significant difference between trainers regarding the incidence of dorsal metacarpal disease and average speed of their horses. 2-year-olds under care of trainers whose horses had the highest incidence o dorsal metacarpal disease also were the fastest one's. Therefore, fast speed associated with longer distances (700m and trainer are factors that predispose young horses to dorsal metacarpal disease.

[Comparative analysis of one- and two-stage augmentation urethroplasty with dorsal INLAY buccal graft for extended stricturesof spongious urethra].

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Kogan, M I; Glukhov, V P; Mitusov, V V; Krasulin, V V; Ilyash, A V

2018-03-01

Urethral reconstructive surgery is in constant development. At present, reconstructive urethroplasty with buccal mucosa is increasingly being used. The study aimed to compare the results of a one- and two-stage augmentation urethroplasty with dorsal inlay buccal graft for strictures of the spongious urethra. The study comprised 72 patients aged 19-64 with urethral strictures 3-18 cm long. In 34 (47.2%) patients, the stricture was localized in the penile urethra, in 30 patients (41.6%) in the penile-bulbous urethra and in 8 patients (11%) in the bulbous urethra. All patients underwent augmentation urethroplasty with dorsal inlay buccal graft. The results were evaluated separately in 55 (76.4%, group 1) and 17 (23.6%, group 2) patients who underwent one-stage and two-stage surgery, respectively. The incidence rate of early postoperative complications was higher after one-stage (23.6%) compared two-stage surgery (11.8%) (purethroplasty with dorsal inlay buccal graft was achieved in 88.9% of patients; treatment effectiveness in the group 1 was 89.1%, in the group 2 - 88.2% (p>0.05). The final effectiveness of the operation, achieved with the use of additional surgical interventions, is estimated at 98.6%. The results of augmentation urethroplasty with dorsal inlay buccal graft do not depend on the number of stages, but fewer complications accompany two-stage surgery.

The effect of exercise frequency on neuropathic pain and pain-related cellular reactions in the spinal cord and midbrain in a rat sciatic nerve injury model

Directory of Open Access Journals (Sweden)

Sumizono M

2018-02-01

Full Text Available Megumi Sumizono,1,2 Harutoshi Sakakima,1 Shotaro Otsuka,1 Takuto Terashi,1 Kazuki Nakanishi,1,2 Koki Ueda,1,2 Seiya Takada,1,2 Kiyoshi Kikuchi3 1Course of Physical Therapy, School of Health Sciences, Faculty of Medicine, Kagoshima University, Kagoshima, Japan; 2Kirishima Orthopedics, Kirishima, Japan; 3Division of Brain Science, Department of Physiology, Kurume University School of Medicine, Kurume, Japan Background: Exercise regimens are established methods that can relieve neuropathic pain. However, the relationship between frequency and intensity of exercise and multiple cellular responses of exercise-induced alleviation of neuropathic pain is still unclear. We examined the influence of exercise frequency on neuropathic pain and the intracellular responses in a sciatic nerve chronic constriction injury (CCI model. Materials and methods: Rats were assigned to four groups as follows: CCI and high-frequency exercise (HFE group, CCI and low-frequency exercise (LFE group, CCI and no exercise (No-Ex group, and naive animals (control group. Rats ran on a treadmill, at a speed of 20 m/min, for 30 min, for 5 (HFE or 3 (LFE days a week, for a total of 5 weeks. The 50% withdrawal threshold was evaluated for mechanical sensitivity. The activation of glial cells (microglia and astrocytes, expression of brain-derived neurotrophic factor (BDNF and μ-opioid receptor in the spinal dorsal horn and endogenous opioid in the midbrain were examined using immunohistochemistry. Opioid receptor antagonists (naloxone were administered using intraperitoneal injection. Results: The development of neuropathic pain was related to the activation of glial cells, increased BDNF expression, and downregulation of the μ-opioid receptor in the ipsilateral spinal dorsal horn. In the No-Ex group, neuropathic pain showed the highest level of mechanical hypersensitivity at 2 weeks, which improved slightly until 5 weeks after CCI. In both exercise groups, the alleviation of

Thermal effects of dorsal head immersion in cold water on nonshivering humans.

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Giesbrecht, Gordon G; Lockhart, Tamara L; Bristow, Gerald K; Steinman, Allan M

2005-11-01

Personal floatation devices maintain either a semirecumbent flotation posture with the head and upper chest out of the water or a horizontal flotation posture with the dorsal head and whole body immersed. The contribution of dorsal head and upper chest immersion to core cooling in cold water was isolated when the confounding effect of shivering heat production was inhibited with meperidine (Demerol, 2.5 mg/kg). Six male volunteers were immersed four times for up to 60 min, or until esophageal temperature = 34 degrees C. An insulated hoodless dry suit or two different personal floatation devices were used to create four conditions: 1) body insulated, head out; 2) body insulated, dorsal head immersed; 3) body exposed, head (and upper chest) out; and 4) body exposed, dorsal head (and upper chest) immersed. When the body was insulated, dorsal head immersion did not affect core cooling rate (1.1 degrees C/h) compared with head-out conditions (0.7 degrees C/h). When the body was exposed, however, the rate of core cooling increased by 40% from 3.6 degrees C/h with the head out to 5.0 degrees C/h with the dorsal head and upper chest immersed (P immersed (approximately 10%). The exaggerated core cooling during dorsal head immersion (40% increase) may result from the extra heat loss affecting a smaller thermal core due to intense thermal stimulation of the body and head and resultant peripheral vasoconstriction. Dorsal head and upper chest immersion in cold water increases the rate of core cooling and decreases potential survival time.

Key role for spinal dorsal horn microglial kinin B1 receptor in early diabetic pain neuropathy

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Couture Réjean

2010-06-01

Full Text Available Abstract Background The pro-nociceptive kinin B1 receptor (B1R is upregulated on sensory C-fibres, astrocytes and microglia in the spinal cord of streptozotocin (STZ-diabetic rat. This study aims at defining the role of microglial kinin B1R in diabetic pain neuropathy. Methods Sprague-Dawley rats were made diabetic with STZ (65 mg/kg, i.p., and 4 days later, two specific inhibitors of microglial cells (fluorocitrate, 1 nmol, i.t.; minocycline, 10 mg/kg, i.p. were administered to assess the impact on thermal hyperalgesia, allodynia and mRNA expression (qRT-PCR of B1R and pro-inflammatory markers. Spinal B1R binding sites ((125I-HPP-desArg10-Hoe 140 were also measured by quantitative autoradiography. Inhibition of microglia was confirmed by confocal microscopy with the specific marker Iba-1. Effects of intrathecal and/or systemic administration of B1R agonist (des-Arg9-BK and antagonists (SSR240612 and R-715 were measured on neuropathic pain manifestations. Results STZ-diabetic rats displayed significant tactile and cold allodynia compared with control rats. Intrathecal or peripheral blockade of B1R or inhibition of microglia reversed time-dependently tactile and cold allodynia in diabetic rats without affecting basal values in control rats. Microglia inhibition also abolished thermal hyperalgesia and the enhanced allodynia induced by intrathecal des-Arg9-BK without affecting hyperglycemia in STZ rats. The enhanced mRNA expression (B1R, IL-1β, TNF-α, TRPV1 and Iba-1 immunoreactivity in the STZ spinal cord were normalized by fluorocitrate or minocycline, yet B1R binding sites were reduced by 38%. Conclusion The upregulation of kinin B1R in spinal dorsal horn microglia by pro-inflammatory cytokines is proposed as a crucial mechanism in early pain neuropathy in STZ-diabetic rats.

CARDIOVASCULAR EFFECTS AND CHANGES IN MIDBRAIN PERIAQUEDUCTAL GRAY NEURONAL-ACTIVITY INDUCED BY ELECTRICAL-STIMULATION OF THE HYPOTHALAMUS IN THE RAT

NARCIS (Netherlands)

VANDERPLAS, J; WIERSINGAPOST, JEC; MAES, FW; BOHUS, B

1995-01-01

The effects of low-intensity electrical stimulation of sites in the hypothalamus and zona incerta (ZI) on mean blood pressure (MBP), heart rate (HR), and neuronal activity in the midbrain periaqueductal gray (FAG) were investigated in rats. Longlasting depressor responses were elicited from 67 sites

Maternal xNorrin, a canonical Wnt signaling agonist and TGF-β antagonist, controls early neuroectoderm specification in Xenopus.

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Suhong Xu

Full Text Available Dorsal-ventral specification in the amphibian embryo is controlled by β-catenin, whose activation in all dorsal cells is dependent on maternal Wnt11. However, it remains unknown whether other maternally secreted factors contribute to β-catenin activation in the dorsal ectoderm. Here, we show that maternal Xenopus Norrin (xNorrin promotes anterior neural tissue formation in ventralized embryos. Conversely, when xNorrin function is inhibited, early canonical Wnt signaling in the dorsal ectoderm and the early expression of the zygotic neural inducers Chordin, Noggin, and Xnr3 are severely suppressed, causing the loss of anterior structures. In addition, xNorrin potently inhibits BMP- and Nodal/Activin-related functions through direct binding to the ligands. Moreover, a subset of Norrin mutants identified in humans with Norrie disease retain Wnt activation but show defective inhibition of Nodal/Activin-related signaling in mesoderm induction, suggesting that this disinhibition causes Norrie disease. Thus, xNorrin is an unusual molecule that acts on two major signaling pathways, Wnt and TGF-β, in opposite ways and is essential for early neuroectoderm specification.

Lasting Differential Effects on Plasticity Induced by Prenatal Stress in Dorsal and Ventral Hippocampus

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Gayane Grigoryan

2016-01-01

Full Text Available Early life adversaries have a profound impact on the developing brain structure and functions that persist long after the original traumatic experience has vanished. One of the extensively studied brain structures in relation to early life stress has been the hippocampus because of its unique association with cognitive processes of the brain. While the entire hippocampus shares the same intrinsic organization, it assumes different functions in its dorsal and ventral sectors (DH and VH, resp., based on different connectivity with other brain structures. In the present review, we summarize the differences between DH and VH and discuss functional and structural effects of prenatal stress in the two sectors, with the realization that much is yet to be explored in understanding the opposite reactivity of the DH and VH to stressful stimulation.

NK3 Receptors mediate an increase in firing rate of midbrain dopamine neurons of the rat and the guinea pig

NARCIS (Netherlands)

Werkman, T.R.; McCreary, A.C.; Kruse, C.G.; Wadman, W.J.

2011-01-01

This in vitro study investigates and compares the effects of NK3 receptor ligands on the firing rate of rat and guinea pig midbrain dopamine neurons. The findings are discussed in the light of choosing suitable animal models for investigating pharmacological properties of NK3 receptor antagonists,

Dorsal buccal mucosal graft urethroplasty for anterior urethral stricture by Asopa technique.

Science.gov (United States)

Pisapati, V L N Murthy; Paturi, Srimannarayana; Bethu, Suresh; Jada, Srikanth; Chilumu, Ramreddy; Devraj, Rahul; Reddy, Bhargava; Sriramoju, Vidyasagar

2009-07-01

Buccal mucosal graft (BMG) substitution urethroplasty has become popular in the management of intractable anterior urethral strictures with good results. Excellent long-term results have been reported by both dorsal and ventral onlay techniques. Asopa reported a successful technique for dorsal placement of BMG in long anterior urethral strictures through a ventral sagittal approach. To evaluate prospectively the results and advantages of dorsal BMG urethroplasty for recurrent anterior urethral strictures by a ventral sagittal urethrotomy approach (Asopa technique). From December 2002 to December 2007, a total of 58 men underwent dorsal BMG urethroplasty by a ventral sagittal urethrotomy approach for recurrent urethral strictures. Forty-five of these patients with a follow-up period of 12-60 mo were prospectively evaluated, and the results were analysed. The urethra was split twice at the site of the stricture both ventrally and dorsally without mobilising it from its bed, and the buccal mucosal graft was secured in the dorsal urethral defect. The urethra was then retubularised in one stage. The overall results were good (87%), with a mean follow-up period of 42 mo. Seven patients developed minor wound infection, and five patients developed fistulae. There were six recurrences (6:45, 13%) during the follow-up period of 12-60 mo. Two patients with a panurethral stricture and four with bulbar or penobulbar strictures developed recurrences and were managed by optical urethrotomy and self-dilatation. The medium-term results were as good as those reported with the dorsal urethrotomy approach. Long-term results from this and other series are awaited. More randomised trials and meta-analyses are needed to establish this technique as a procedure of choice in future. The ventral sagittal urethrotomy approach is easier to perform than the dorsal urethrotomy approach, has good results, and is especially useful in long anterior urethral strictures.

Electrophysiological Assessment of Serotonin and GABA Neuron Function in the Dorsal Raphe during the Third Trimester Equivalent Developmental Period in Mice.

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Morton, Russell A; Yanagawa, Yuchio; Valenzuela, C Fernando

2015-01-01

Alterations in the development of the serotonin system can have prolonged effects, including depression and anxiety disorders later in life. Serotonin axonal projections from the dorsal raphe undergo extensive refinement during the first 2 weeks of postnatal life in rodents (equivalent to the third trimester of human pregnancy). However, little is known about the functional properties of serotonin and GABA neurons in the dorsal raphe during this critical developmental period. We assessed the functional properties and synaptic connectivity of putative serotoninergic neurons and GABAergic neurons in the dorsal raphe during early [postnatal day (P) P5-P7] and late (P15-P17) stages of the third trimester equivalent period using electrophysiology. Our studies demonstrate that GABAergic neurons are hyperexcitable at P5-P7 relative to P15-P17. Furthermore, putative serotonin neurons exhibit an increase in both excitatory and GABAA receptor-mediated spontaneous postsynaptic currents during this developmental period. Our data suggest that GABAergic neurons and putative serotonin neurons undergo significant electrophysiological changes during neonatal development.

Wnt5a cooperates with canonical Wnts to generate midbrain dopaminergic neurons in vivo and in stem cells

Czech Academy of Sciences Publication Activity Database

Andersson, E.R.; Salto, C.; Villaescusa, J.C.; Cajanek, L.; Yang, S.; Bryjová, Lenka; Nagy, I.I.; Vainio, S.J.; Ramírez, C.; Bryja, Vítězslav; Arenas, E.

2013-01-01

Roč. 110, č. 7 (2013), E602-E610 ISSN 0027-8424 Grant - others:GA ČR(CZ) GA204/09/0498; GA ČR(CZ) GAP301/11/0747 Institutional research plan: CEZ:AV0Z50040702 Institutional support: RVO:68081707 Keywords : VENTRAL MIDBRAIN * PARKINSONS-DISEASE * BETA-CATENIN Subject RIV: BO - Biophysics Impact factor: 9.809, year: 2013

Time-dependent effects of repeated THC treatment on dopamine D2/3 receptor-mediated signalling in midbrain and striatum.

Science.gov (United States)

Tournier, Benjamin B; Tsartsalis, Stergios; Dimiziani, Andrea; Millet, Philippe; Ginovart, Nathalie

2016-09-15

This study examined the time-course of alterations in levels and functional sensitivities of dopamine D2/3 receptors (D2/3R) during the course and up to 6 weeks following cessation of chronic treatment with Delta(9)-Tetrahydrocannabinol (THC) in rats. THC treatment led to an increase in D2/3R levels in striatum, as assessed using [(3)H]-(+)-PHNO, that was readily observable after one week of treatment, remained stably elevated during the subsequent 2 weeks of treatment, but fully reversed within 2 weeks of THC discontinuation. THC-induced D2/3R alterations were more pronounced and longer lasting in the dopamine cell body regions of the midbrain, wherein [(3)H]-(+)-PHNO binding was still elevated at 2 weeks but back to control values at 6 weeks after THC cessation. Parallel analyses of the psychomotor effects of pre- and post-synaptic doses of quinpirole also showed a pattern of D2/3R functional supersensitivity indicative of more rapid subsidence in striatum than in midbrain following drug cessation. These results indicate that chronic THC is associated with a biochemical and functional sensitization of D2/3R signaling, that these responses show a region-specific temporal pattern and are fully reversible following drug discontinuation. These results suggest that an increased post-synaptic D2/3R function and a decreased DA presynaptic signaling, mediated by increased D2/3R autoinhibition, may predominate during distinct phases of withdrawal and may contribute both to the mechanisms leading to relapse and to cannabinoid withdrawal symptoms. The different rates of normalization of D2/3R function in striatum and midbrain may be critical information for the development of new pharmacotherapies for cannabis dependence. Copyright © 2016 Elsevier B.V. All rights reserved.

The issue of ventral versus dorsal approach in bulbar urethral ...

African Journals Online (AJOL)

E. Palminteri

From surgical point of view, the Barbagli Dorsal Grafting by Dor- sal approach [8] gives a good support for the graft; Barbagli stated that his technique offers a wider augmentation than ventral or dorsal grafting using the ventral approach. The good spongiosum covering seems reduce the risk of fistula; in reality there is a ...

bullwinkle and shark regulate dorsal-appendage morphogenesis in Drosophila oogenesis.

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Tran, David H; Berg, Celeste A

2003-12-01

bullwinkle (bwk) regulates embryonic anteroposterior patterning and, through a novel germline-to-soma signal, morphogenesis of the eggshell dorsal appendages. We screened for dominant modifiers of the bullwinkle mooseantler eggshell phenotype and identified shark, which encodes an SH2-domain, ankyrin-repeat tyrosine kinase. At the onset of dorsal-appendage formation, shark is expressed in a punctate pattern in the squamous stretch cells overlying the nurse cells. Confocal microscopy with cell-type-specific markers demonstrates that the stretch cells act as a substrate for the migrating dorsal-appendage-forming cells and extend cellular projections towards them. Mosaic analyses reveal that shark is required in follicle cells for cell migration and chorion deposition. Proper shark RNA expression in the stretch cells requires bwk activity, while restoration of shark expression in the stretch cells suppresses the bwk dorsal-appendage phenotype. These results suggest that shark plays an important downstream role in the bwk-signaling pathway. Candidate testing implicates Src42A in a similar role, suggesting conservation with a vertebrate signaling pathway involving non-receptor tyrosine kinases.

Specific and spatial labeling of P0-Cre versus Wnt1-Cre in cranial neural crest in early mouse embryos.

Science.gov (United States)

Chen, Guiqian; Ishan, Mohamed; Yang, Jingwen; Kishigami, Satoshi; Fukuda, Tomokazu; Scott, Greg; Ray, Manas K; Sun, Chenming; Chen, Shi-You; Komatsu, Yoshihiro; Mishina, Yuji; Liu, Hong-Xiang

2017-06-01

P0-Cre and Wnt1-Cre mouse lines have been widely used in combination with loxP-flanked mice to label and genetically modify neural crest (NC) cells and their derivatives. Wnt1-Cre has been regarded as the gold standard and there have been concerns about the specificity of P0-Cre because it is not clear about the timing and spatial distribution of the P0-Cre transgene in labeling NC cells at early embryonic stages. We re-visited P0-Cre and Wnt1-Cre models in the labeling of NC cells in early mouse embryos with a focus on cranial NC. We found that R26-lacZ Cre reporter responded to Cre activity more reliably than CAAG-lacZ Cre reporter during early embryogenesis. Cre immunosignals in P0-Cre and reporter (lacZ and RFP) activity in P0-Cre/R26-lacZ and P0-Cre/R26-RFP embryos was detected in the cranial NC and notochord regions in E8.0-9.5 (4-19 somites) embryos. P0-Cre transgene expression was observed in migrating NC cells and was more extensive in the forebrain and hindbrain but not apparent in the midbrain. Differences in the Cre distribution patterns of P0-Cre and Wnt1-Cre were profound in the midbrain and hindbrain regions, that is, extensive in the midbrain of Wnt1-Cre and in the hindbrain of P0-Cre embryos. The difference between P0-Cre and Wnt1-Cre in labeling cranial NC may provide a better explanation of the differential distributions of their NC derivatives and of the phenotypes caused by Cre-driven genetic modifications. © 2017 Wiley Periodicals, Inc.

Attention modulates the dorsal striatum response to love stimuli.

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Langeslag, Sandra J E; van der Veen, Frederik M; Röder, Christian H

2014-02-01

In previous functional magnetic resonance imaging (fMRI) studies concerning romantic love, several brain regions including the caudate and putamen have consistently been found to be more responsive to beloved-related than control stimuli. In those studies, infatuated individuals were typically instructed to passively view the stimuli or to think of the viewed person. In the current study, we examined how the instruction to attend to, or ignore the beloved modulates the response of these brain areas. Infatuated individuals performed an oddball task in which pictures of their beloved and friend served as targets and distractors. The dorsal striatum showed greater activation for the beloved than friend, but only when they were targets. The dorsal striatum actually tended to show less activation for the beloved than the friend when they were distractors. The longer the love and relationship duration, the smaller the response of the dorsal striatum to beloved-distractor stimuli was. We interpret our findings in terms of reinforcement learning. By virtue of using a cognitive task with a full factorial design, we show that the dorsal striatum is not activated by beloved-related information per se, but only by beloved-related information that is attended. Copyright © 2012 Wiley Periodicals, Inc.

Vertical diplopia and oscillopsia due to midbrain keyhole aqueduct syndrome associated with severe cough.

Science.gov (United States)

Oh, Angela Jinsook; Lanzman, Bryan Alexander; Liao, Yaping Joyce

2018-06-01

Midline structural defects in the neural axis can give rise to neuro-ophthalmic symptoms. We report a rare case of keyhole aqueduct syndrome presenting after two years of severe cough due to gastroesophageal reflux disease. A 58-year-old woman with a 2-year history of daily, severe cough presented to the neuro-ophthalmology clinic with progressive diplopia and oscillopsia. Examination revealed a 1-2 Hz down-beating nystagmus in primary gaze that worsened with left, right, and down gazes. Gaze evoked nystagmus and mild paresis were also seen with up gaze. There was an incomitant left hypertropia due to skew deviation that worsened with right and up gazes and improved with down gaze. She also had a right-sided ptosis and a 3 mm anisocoria not due to cranial nerve 3 paresis or Horner's syndrome. Brain magnetic resonance imaging showed a 1.5 mm × 11.7 mm × 6 mm midline cleft in the ventral midbrain communicating with the cerebral aqueduct, consistent with keyhole aqueduct syndrome. Her nystagmus and diplopia improved with oral acetazolamide treatment, at high doses of 2500-3000 mg per day. We report the first case of midbrain keyhole aqueduct syndrome with ocular motor and other neuro-ophthalmic manifestations associated with severe cough. Although her cough was effectively treated and intracranial pressure measurement was normal, her ophthalmic symptoms continued to progress, which is common in previous cases reported. Treatment with acetazolamide led to significant improvement, supporting the use of acetazolamide in this rare condition.

The dorsal thoracic fascia: anatomic significance with clinical applications in reconstructive microsurgery.

Science.gov (United States)

Kim, P S; Gottlieb, J R; Harris, G D; Nagle, D J; Lewis, V L

1987-01-01

The anatomic distribution and potential arterial flow patterns of the circumflex scapular artery were investigated by Microfil injection. These studies demonstrated that the circumflex scapular artery lies within the dorsal thoracic fascia, which plays a significant role in the circulation of the overlying skin and subcutaneous tissue. We conclude that scapular/parascapular flaps are fasciocutaneous flaps, the dorsal thoracic fascia can be transferred as a free flap without its overlying skin and subcutaneous tissue, and intercommunication exists between the myocutaneous perforators of the latissimus dorsi myocutaneous flap and the vascular plexus of the dorsal thoracic fascia. We present microvascular cases in which the vascular properties of the dorsal thoracic fascia facilitated wound closure with free fascia flaps or expanded cutaneous or myocutaneous flaps.

Role of the cyclooxygenase 2-thromboxane pathway in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced decrease in mesencephalic vein blood flow in the zebrafish embryo

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Teraoka, Hiroki; Kubota, Akira; Dong, Wu; Kawai, Yusuke; Yamazaki, Koji; Mori, Chisato; Harada, Yoshiteru; Peterson, Richard E.; Hiraga, Takeo

2009-01-01

Previously, we reported that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) evoked developmental toxicity required activation of aryl hydrocarbon receptor type 2 (AHR2), using zebrafish embryos. However, the downstream molecular targets of AHR2 activation are largely unknown and are the focus of the present investigation. TCDD induces cyclooxygenase 2 (COX2), a rate-limiting enzyme for prostaglandin synthesis in certain cells. In the present study, we investigated the role of the COX2-thromboxane pathway in causing a specific endpoint of TCDD developmental toxicity in the zebrafish embryo, namely, a decrease in regional blood flow in the dorsal midbrain. It was found that the TCDD-induced reduction in mesencephalic vein blood flow was markedly inhibited by selective COX2 inhibitors, NS-398 and SC-236, and by a general COX inhibitor, indomethacin, but not by a selective COX1 inhibitor, SC-560. Gene knock-down of COX2 by two different types of morpholino antisense oligonucleotides, but not by their negative homologs, also protected the zebrafish embryos from mesencephalic vein circulation failure caused by TCDD. This inhibitory effect of TCDD on regional blood flow in the dorsal midbrain was also blocked by selective antagonists of the thromboxane receptor (TP). Treatment of control zebrafish embryos with a TP agonist also caused a reduction in mesencephalic vein blood flow and it too was blocked by a TP antagonist, without any effect on trunk circulation. Finally, gene knock-down of thromboxane A synthase 1 (TBXS) with morpholinos but not by the morpholinos' negative homologs provided significant protection against TCDD-induced mesencephalic circulation failure. Taken together, these results point to a role of the prostanoid synthesis pathway via COX2-TBXS-TP in the local circulation failure induced by TCDD in the dorsal midbrain of the zebrafish embryo

Long-Lasting Sound-Evoked Afterdischarge in the Auditory Midbrain.

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Ono, Munenori; Bishop, Deborah C; Oliver, Douglas L

2016-02-12

Different forms of plasticity are known to play a critical role in the processing of information about sound. Here, we report a novel neural plastic response in the inferior colliculus, an auditory center in the midbrain of the auditory pathway. A vigorous, long-lasting sound-evoked afterdischarge (LSA) is seen in a subpopulation of both glutamatergic and GABAergic neurons in the central nucleus of the inferior colliculus of normal hearing mice. These neurons were identified with single unit recordings and optogenetics in vivo. The LSA can continue for up to several minutes after the offset of the sound. LSA is induced by long-lasting, or repetitive short-duration, innocuous sounds. Neurons with LSA showed less adaptation than the neurons without LSA. The mechanisms that cause this neural behavior are unknown but may be a function of intrinsic mechanisms or the microcircuitry of the inferior colliculus. Since LSA produces long-lasting firing in the absence of sound, it may be relevant to temporary or chronic tinnitus or to some other aftereffect of long-duration sound.

Compound dorsal dislocation of lunate with trapezoid fracture

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Bong-Sung Kim

2016-12-01

Full Text Available We report about a dorsal dislocation of the lunate accompanied by a trapezoid fracture in a 41-year old male patient after a motorcycle accident. The lunate dislocation with no dorsal or volar intercalated segment instability (DISI, VISI was diagnosed by x-ray whereas the trapezoid fracture was only diagnosable by computed tomography. A closed reduction and internal fixation of the lunate by two Kirschner wires was performed, the trapezoid fracture was conservatively treated. Surgery was followed by immobilization, intense physiotherapy and close follow-up. Even though complaints such as swelling and pain subsided during the course of rehabilitation, partial loss of strength and range of motion remained even after 16 months. In conclusion, a conservative treatment of trapezoid fractures seems to be sufficient in most cases. Closed reduction with Kwire fixation led to an overall satisfactory result in our case. For dorsal lunate dislocations in general, open reduction should be performed when close reduction is unsuccessful or DISI/VISI are observed in radiographs after attempted close reduction.

Effects of dopamine medication on sequence learning with stochastic feedback in Parkinson's disease

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Moonsang Seo

2010-08-01

Full Text Available A growing body of evidence suggests that the midbrain dopamine system plays a key role in reinforcement learning and disruption of the midbrain dopamine system in Parkinson's disease (PD may lead to deficits on tasks that require learning from feedback. We examined how changes in dopamine levels (‘ON’ and ‘OFF’ their dopamine medication affect sequence learning from stochastic positive and negative feedback using Bayesian reinforcement learning models. We found deficits in sequence learning in patients with PD when they were ‘ON’ and ‘OFF’ medication relative to healthy controls, but smaller differences between patients ‘OFF’ and ‘ON’. The deficits were mainly due to decreased learning from positive feedback, although across all participant groups learning was more strongly associated with positive than negative feedback in our task. The learning in our task is likely mediated by the relatively depleted dorsal striatum and not the relatively intact ventral striatum. Therefore, the changes we see in our task may be due to a strong loss of phasic dopamine signals in the dorsal striatum in PD.

Effects of Dopamine Medication on Sequence Learning with Stochastic Feedback in Parkinson's Disease

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Seo, Moonsang; Beigi, Mazda; Jahanshahi, Marjan; Averbeck, Bruno B.

2010-01-01

A growing body of evidence suggests that the midbrain dopamine system plays a key role in reinforcement learning and disruption of the midbrain dopamine system in Parkinson's disease (PD) may lead to deficits on tasks that require learning from feedback. We examined how changes in dopamine levels (“ON” and “OFF” their dopamine medication) affect sequence learning from stochastic positive and negative feedback using Bayesian reinforcement learning models. We found deficits in sequence learning in patients with PD when they were “ON” and “OFF” medication relative to healthy controls, but smaller differences between patients “OFF” and “ON”. The deficits were mainly due to decreased learning from positive feedback, although across all participant groups learning was more strongly associated with positive than negative feedback in our task. The learning in our task is likely mediated by the relatively depleted dorsal striatum and not the relatively intact ventral striatum. Therefore, the changes we see in our task may be due to a strong loss of phasic dopamine signals in the dorsal striatum in PD. PMID:20740077

Dissociated repetition deficits in aphasia can reflect flexible interactions between left dorsal and ventral streams and gender-dimorphic architecture of the right dorsal stream.

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Berthier, Marcelo L; Froudist Walsh, Seán; Dávila, Guadalupe; Nabrozidis, Alejandro; Juárez Y Ruiz de Mier, Rocío; Gutiérrez, Antonio; De-Torres, Irene; Ruiz-Cruces, Rafael; Alfaro, Francisco; García-Casares, Natalia

2013-01-01

Assessment of brain-damaged subjects presenting with dissociated repetition deficits after selective injury to either the left dorsal or ventral auditory pathways can provide further insight on their respective roles in verbal repetition. We evaluated repetition performance and its neural correlates using multimodal imaging (anatomical MRI, DTI, fMRI, and(18)FDG-PET) in a female patient with transcortical motor aphasia (TCMA) and in a male patient with conduction aphasia (CA) who had small contiguous but non-overlapping left perisylvian infarctions. Repetition in the TCMA patient was fully preserved except for a mild impairment in nonwords and digits, whereas the CA patient had impaired repetition of nonwords, digits and word triplet lists. Sentence repetition was impaired, but he repeated novel sentences significantly better than clichés. The TCMA patient had tissue damage and reduced metabolism in the left sensorimotor cortex and insula. DTI showed damage to the left temporo-frontal and parieto-frontal segments of the arcuate fasciculus (AF) and part of the left ventral stream together with well-developed right dorsal and ventral streams, as has been reported in more than one-third of females. The CA patient had tissue damage and reduced metabolic activity in the left temporoparietal cortex with additional metabolic decrements in the left frontal lobe. DTI showed damage to the left temporo-parietal and temporo-frontal segments of the AF, but the ventral stream was spared. The direct segment of the AF in the right hemisphere was also absent with only vestigial remains of the other dorsal subcomponents present, as is often found in males. fMRI during word and nonword repetition revealed bilateral perisylvian activation in the TCMA patient suggesting recruitment of spared segments of the left dorsal stream and right dorsal stream with propagation of signals to temporal lobe structures suggesting a compensatory reallocation of resources via the ventral streams. The

Amnioserosa cell constriction but not epidermal actin cable tension autonomously drives dorsal closure.

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Pasakarnis, Laurynas; Frei, Erich; Caussinus, Emmanuel; Affolter, Markus; Brunner, Damian

2016-11-01

Tissue morphogenesis requires coordination of multiple force-producing components. During dorsal closure in fly embryogenesis, an epidermis opening closes. A tensioned epidermal actin/MyosinII cable, which surrounds the opening, produces a force that is thought to combine with another MyosinII force mediating apical constriction of the amnioserosa cells that fill the opening. A model proposing that each force could autonomously drive dorsal closure was recently challenged by a model in which the two forces combine in a ratchet mechanism. Acute force elimination via selective MyosinII depletion in one or the other tissue shows that the amnioserosa tissue autonomously drives dorsal closure while the actin/MyosinII cable cannot. These findings exclude both previous models, although a contribution of the ratchet mechanism at dorsal closure onset remains likely. This shifts the current view of dorsal closure being a combinatorial force-component system to a single tissue-driven closure event.

Complete dorsal pancreatic agenesis and unilateral renal agenesis.

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Moreira, Adriana; Carvalho, André; Portugal, Inês; Jesus, José Miguel

2018-02-01

Dorsal pancreatic agenesis is a very rare congenital anomaly. Unilateral renal agenesis, on the other hand, is a relatively common congenital anomaly, although its etiology is not fully understood. Renal and pancreatic embryologic development appears to be nonrelated. We report a case of a 34-year-old man who was referred to our hospital for evaluation of cholestasis and microalbuminuria. Ultrasound and magnetic resonance imaging examinations showed empty right renal fossa and absence of the pancreatic neck, body, and tail. Our case report is the second case of a dorsal pancreatic agenesis and unilateral renal agenesis in a young male patient.

Primary afferent terminal sprouting after a cervical dorsal rootlet section in the macaque monkey.

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Darian-Smith, Corinna

2004-03-01

We examined the role of primary afferent neurons in the somatosensory cortical "reactivation" that occurs after a localized cervical dorsal root lesion (Darian-Smith and Brown [2000] Nat. Neurosci. 3:476-481). After section of the dorsal rootlets that enervate the macaque's thumb and index finger (segments C6-C8), the cortical representation of these digits was initially silenced but then re-emerged for these same digits over 2-4 postlesion months. Cortical reactivation was accompanied by the emergence of physiologically detectable input from these same digits within dorsal rootlets bordering the lesion site. We investigated whether central axonal sprouting of primary afferents spared by the rhizotomy could mediate this cortical reactivation. The cortical representation of the hand was mapped electrophysiologically 15-25 weeks after the dorsal rootlet section to define this reactivation. Cholera toxin subunit B conjugated to horseradish peroxidase was then injected into the thumb and index finger pads bilaterally to label the central terminals of any neurons that innervated these digits. Primary afferent terminal proliferation was assessed in the spinal dorsal horn and cuneate nucleus at 7 days and 15-25 postlesion weeks. Labeled terminal bouton distributions were reconstructed and the "lesion" and control sides compared within each monkey. Distributions were significantly larger on the side of the lesion in the dorsal horn and cuneate nucleus at 15-25 weeks after the dorsal rootlet section, than those mapped only 7 days postlesion. Our results provide direct evidence for localized sprouting of spared (uninjured) primary afferent terminals in the dorsal horn and cuneate nucleus after a restricted dorsal root injury. Copyright 2004 Wiley-Liss, Inc.

Detection of genes regulated by Lmx1b during limb dorsalization.

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Feenstra, Jennifer M; Kanaya, Kohei; Pira, Charmaine U; Hoffman, Sarah E; Eppey, Richard J; Oberg, Kerby C

2012-05-01

Lmx1b is a homeodomain transcription factor that regulates dorsal identity during limb development. Lmx1b knockout (KO) mice develop distal ventral-ventral limbs. Although induction of Lmx1b is linked to Wnt7a expression in the dorsal limb ectoderm, the downstream targets of Lmx1b that accomplish limb dorsalization are unknown. To identify genes targeted by Lmx1b, we compared gene arrays from Lmx1b KO and wild type mouse limbs during limb dorsalization, i.e., 11.5, 12.5, and 13.5 days post coitum. We identified 54 target genes that were differentially expressed in all three stages. Several skeletal targets, including Emx2, Matrilin1 and Matrilin4, demonstrated a loss of scapular expression in the Lmx1b KO mice, supporting a role for Lmx1b in scapula development. Furthermore, the relative abundance of extracellular matrix-related soft tissue targets regulated by Lmx1b, such as collagens and proteoglycans, suggests a mechanism that includes changes in the extracellular matrix composition to accomplish limb dorsalization. Our study provides the most comprehensive characterization of genes regulated by Lmx1b during limb development to-date and provides targets for further investigation. © 2012 The Authors. Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

Topography and collateralization of dopaminergic projections to primary motor cortex in rats.

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Hosp, Jonas A; Nolan, Helen E; Luft, Andreas R

2015-05-01

Dopaminergic signaling within the primary motor cortex (M1) is necessary for successful motor skill learning. Dopaminergic neurons projecting to M1 are located in the ventral tegmental area (VTA, nucleus A10) of the midbrain. It is unknown which behavioral correlates are encoded by these neurons. The objective here is to investigate whether VTA-M1 fibers are collaterals of projections to prefrontal cortex (PFC) or nucleus accumbens (NAc) or if they form a distinct pathway. In rats, multiple-site retrograde fluorescent tracers were injected into M1, PFC and the core region of the NAc and VTA sections investigated for concomitant labeling of different tracers. Dopaminergic neurons projecting to M1, PFC and NAc were found in nucleus A10 and to a lesser degree in the medial nucleus A9. Neurons show high target specificity, minimal collateral branching to other than their target area and hardly cross the midline. Whereas PFC- and NAc-projecting neurons are indistinguishably intermingled within the ventral portion of dopaminergic nuclei in middle and caudal midbrain, M1-projecting neurons are only located within the dorsal part of the rostral midbrain. Within M1, the forelimb representation receives sevenfold more dopaminergic projections than the hindlimb representation. This strong rostro-caudal gradient as well as the topographical preference to dorsal structures suggest that projections to M1 emerged late in the development of the dopaminergic systems in and form a functionally distinct system.

Dorsal Phalloplasty to Preserve Penis Length after Penile Prosthesis Implantation

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Osama Shaeer

2017-03-01

Full Text Available Objectives: Following penile prosthesis implantation (PPI, patients may complain of a decrease in visible penis length. A dorsal phalloplasty defines the penopubic junction by tacking pubic skin to the pubis, revealing the base of the penis. This study aimed to evaluate the efficacy of a dorsal phalloplasty in increasing the visible penis length following PPI. Methods: An inflatable penile prosthesis was implanted in 13 patients with severe erectile dysfunction (ED at the Kamal Shaeer Hospital, Cairo, Egypt, from January 2013 to May 2014. During the surgery, nonabsorbable tacking sutures were used to pin the pubic skin to the pubis through the same penoscrotal incision. Intraoperative penis length was measured before and after the dorsal phalloplasty. Overall patient satisfaction was measured on a 5-point rating scale and patients were requested to subjectively compare their postoperative penis length with memories of their penis length before the onset of ED. Results: Intraoperatively, the dorsal phalloplasty increased the visible length of the erect penis by an average of 25.6%. The average length before and after tacking was 10.2 ± 2.9 cm and 13.7 ± 2.8 cm, respectively (P <0.002. Postoperatively, seven patients (53.8% reported a longer penis, five patients (38.5% reported no change in length and one patient (7.7% reported a slightly shorter penis. The mean overall patient satisfaction score was 4.9 ± 0.3. None of the patients developed postoperative complications. Conclusion: A dorsal phalloplasty during PPI is an effective method of increasing visible penis length, therefore minimising the impression of a shorter penis after implantation.

Beyond the midbrain atrophy: wide spectrum of structural MRI finding in cases of pathologically proven progressive supranuclear palsy

International Nuclear Information System (INIS)

Sakurai, Keita; Tokumaru, Aya M.; Shimoji, Keigo; Murayama, Shigeo; Kanemaru, Kazutomi; Morimoto, Satoru; Aiba, Ikuko; Nakagawa, Motoo; Ozawa, Yoshiyuki; Shimohira, Masashi; Shibamoto, Yuta; Matsukawa, Noriyuki; Hashizume, Yoshio

2017-01-01

Recently, it has been recognized that pathologically proven progressive supranuclear palsy (PSP) cases are classified into various clinical subtypes with non-uniform symptoms and imaging findings. This article reviews essential imaging findings, general information, and advanced magnetic resonance imaging (MRI) techniques for PSP and presents these MRI findings of pathologically proven typical and atypical PSP cases for educational purposes. With the review of literatures, notably including atypical pathologically proven PSP cases, MRI and clinical information of 15 pathologically proven typical and atypical PSP cases were retrospectively evaluated. In addition to typical symptoms, PSP patients can exhibit atypical symptoms including levodopa-responsive parkinsonism, pure akinesia, non-fluent aphasia, corticobasal syndrome, and predominant cerebellar ataxia. As well as clinical symptoms, the degree of midbrain atrophy, a well-known imaging hallmark, is not consistent in atypical PSP cases. This fact has important implications for the limitation of midbrain atrophy as a diagnostic imaging biomarker of PSP pathology. Additional evaluation of other imaging findings including various regional atrophies of the globus pallidus, frontal lobe, cerebral peduncle, and superior cerebellar peduncle is essential for the diagnosis of atypical PSP cases. It is necessary for radiologists to recognize the wide clinical and radiological spectra of typical and atypical PSP cases. (orig.)

Beyond the midbrain atrophy: wide spectrum of structural MRI finding in cases of pathologically proven progressive supranuclear palsy

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Sakurai, Keita; Tokumaru, Aya M.; Shimoji, Keigo [Tokyo Metropolitan Medical Center of Gerontology, Department of Diagnostic Radiology, Tokyo (Japan); Murayama, Shigeo; Kanemaru, Kazutomi; Morimoto, Satoru [Tokyo Metropolitan Geriatric Hospital, Department of Neurology, Tokyo (Japan); Aiba, Ikuko [National Hospital Organization Higashi Nagoya National Hospital, Department of Neurology, Nagoya (Japan); Nakagawa, Motoo; Ozawa, Yoshiyuki; Shimohira, Masashi; Shibamoto, Yuta [Nagoya City University Graduate School of Medical Sciences, Department of Radiology, Nagoya (Japan); Matsukawa, Noriyuki [Nagoya City University Graduate School of Medical Sciences, Department of Neurology and Neuroscience, Nagoya (Japan); Hashizume, Yoshio [Fukushimura Hospital, Choju Medical Institute, Toyohashi (Japan)

2017-05-15

Recently, it has been recognized that pathologically proven progressive supranuclear palsy (PSP) cases are classified into various clinical subtypes with non-uniform symptoms and imaging findings. This article reviews essential imaging findings, general information, and advanced magnetic resonance imaging (MRI) techniques for PSP and presents these MRI findings of pathologically proven typical and atypical PSP cases for educational purposes. With the review of literatures, notably including atypical pathologically proven PSP cases, MRI and clinical information of 15 pathologically proven typical and atypical PSP cases were retrospectively evaluated. In addition to typical symptoms, PSP patients can exhibit atypical symptoms including levodopa-responsive parkinsonism, pure akinesia, non-fluent aphasia, corticobasal syndrome, and predominant cerebellar ataxia. As well as clinical symptoms, the degree of midbrain atrophy, a well-known imaging hallmark, is not consistent in atypical PSP cases. This fact has important implications for the limitation of midbrain atrophy as a diagnostic imaging biomarker of PSP pathology. Additional evaluation of other imaging findings including various regional atrophies of the globus pallidus, frontal lobe, cerebral peduncle, and superior cerebellar peduncle is essential for the diagnosis of atypical PSP cases. It is necessary for radiologists to recognize the wide clinical and radiological spectra of typical and atypical PSP cases. (orig.)

Agenesis of the dorsal mesentery presenting in an adolescent

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Anith Chacko

2013-03-01

Full Text Available Agenesis of the dorsal mesentery is a rare occurrence that usually presents in children. It is associated with proximal small bowel malrotation as well as high jejunal atresia with discontinuity of the small bowel. We present a case report of an adolescent presenting with clinical features of proximal small bowel obstruction (confirmed on imaging as well as acute pancreatitis. At laparotomy, he was found to have no dorsal mesentery, without small bowel atresia, and the duodenum was fixed to the posterior abdominal wall. The patient recovered well and remained symptom-free.

Effects of drugs of abuse on putative rostromedial tegmental neurons, inhibitory afferents to midbrain dopamine cells.

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Lecca, Salvatore; Melis, Miriam; Luchicchi, Antonio; Ennas, Maria Grazia; Castelli, Maria Paola; Muntoni, Anna Lisa; Pistis, Marco

2011-02-01

Recent findings have underlined the rostromedial tegmental nucleus (RMTg), a structure located caudally to the ventral tegmental area, as an important site involved in the mechanisms of aversion. RMTg contains γ-aminobutyric acid neurons responding to noxious stimuli, densely innervated by the lateral habenula and providing a major inhibitory projection to reward-encoding midbrain dopamine (DA) neurons. One of the key features of drug addiction is the perseverance of drug seeking in spite of negative and unpleasant consequences, likely mediated by response suppression within neural pathways mediating aversion. To investigate whether the RMTg has a function in the mechanisms of addicting drugs, we studied acute effects of morphine, cocaine, the cannabinoid agonist WIN55212-2 (WIN), and nicotine on putative RMTg neurons. We utilized single unit extracellular recordings in anesthetized rats and whole-cell patch-clamp recordings in brain slices to identify and characterize putative RMTg neurons and their responses to drugs of abuse. Morphine and WIN inhibited both firing rate in vivo and excitatory postsynaptic currents (EPSCs) evoked by stimulation of rostral afferents in vitro, whereas cocaine inhibited discharge activity without affecting EPSC amplitude. Conversely, nicotine robustly excited putative RMTg neurons and enhanced EPSCs, an effect mediated by α7-containing nicotinic acetylcholine receptors. Our results suggest that activity of RMTg neurons is profoundly influenced by drugs of abuse and, as important inhibitory afferents to midbrain DA neurons, they might take place in the complex interplay between the neural circuits mediating aversion and reward.

White noise improves learning by modulating activity in dopaminergic midbrain regions and right superior temporal sulcus.

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Rausch, Vanessa H; Bauch, Eva M; Bunzeck, Nico

2014-07-01

In neural systems, information processing can be facilitated by adding an optimal level of white noise. Although this phenomenon, the so-called stochastic resonance, has traditionally been linked with perception, recent evidence indicates that white noise may also exert positive effects on cognitive functions, such as learning and memory. The underlying neural mechanisms, however, remain unclear. Here, on the basis of recent theories, we tested the hypothesis that auditory white noise, when presented during the encoding of scene images, enhances subsequent recognition memory performance and modulates activity within the dopaminergic midbrain (i.e., substantia nigra/ventral tegmental area, SN/VTA). Indeed, in a behavioral experiment, we can show in healthy humans that auditory white noise-but not control sounds, such as a sinus tone-slightly improves recognition memory. In an fMRI experiment, white noise selectively enhances stimulus-driven phasic activity in the SN/VTA and auditory cortex. Moreover, it induces stronger connectivity between SN/VTA and right STS, which, in addition, exhibited a positive correlation with subsequent memory improvement by white noise. Our results suggest that the beneficial effects of auditory white noise on learning depend on dopaminergic neuromodulation and enhanced connectivity between midbrain regions and the STS-a key player in attention modulation. Moreover, they indicate that white noise could be particularly useful to facilitate learning in conditions where changes of the mesolimbic system are causally related to memory deficits including healthy and pathological aging.

Reinnervating the penis in spina bifida patients in the United States: ilioinguinal-to-dorsal-penile neurorrhaphy in two cases.

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Jacobs, Micah A; Avellino, Anthony M; Shurtleff, David; Lendvay, Thomas S

2013-10-01

Penile sensation is absent in some patients with myelomeningocele owing to the dysfunction of the pudendal nerve. Here, we describe the introduction of penile sensation via ilioinguinal-to-dorsal-penile neurorrhaphy in two patients with penile anesthesia due to neural tube defects. To establish penile sensation via ilioinguinal-to-dorsal-penile-nerve neurorrhaphy. A 20-year-old and a 35-year-old male with L5/S1 myelomeningocele were both highly functioning and ambulatory, with intact ilioinguinal nerve distribution sensation but anesthesia of the penis and glans. They were sexually active and able to ejaculate antegrade. Both had high International Index of Erectile Function scores for confidence to achieve erection sufficient for intercourse. An incision was made from anterior superior iliac crest to the glans penis to expose the inguinal canal and ilioinguinal nerve. The ilioinguinal and dorsal penile nerve were transected and anastomosed. The anastomotic site was then wrapped in a hemostatic agent and a drain was left in place. For penile rehabilitation, both patients were instructed to stimulate the penis while looking at the genitalia to encourage redistribution of perceived sensation. Presence of erogenous penile sensation was tested by neurologic examination and patient feedback, and patients completed sexual health questionnaires. Both patients reported paresthesias of the groin with penile stimulation 1 month after surgery. Both patients are now 24 months postoperative and have erogenous sensation on the ipsilateral glans and shaft during intercourse. Neither patient has difficulty achieving or maintaining erections. We present two patients with dorsal penile reinnervation via the ilioinguinal nerve. Although nerve reinnervation has been used in urological procedures, this is the first description of an attempt to resupply penile sensation via the dorsal penile nerve in the United States with a minimum of 18 months follow-up. Early follow-up suggests

The dorsal skinfold chamber: window into the dynamic interaction of biomaterials with their surrounding host tissue

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MW Laschke

2011-09-01

Full Text Available The implantation of biomaterials into the human body has become an indispensable part of almost all fields of modern medicine. Accordingly, there is an increasing need for appropriate approaches, which can be used to evaluate the suitability of different biomaterials for distinct clinical indications. The dorsal skinfold chamber is a sophisticated experimental model, which has been proven to be extremely valuable for the systematic in vivo analysis of the dynamic interaction of small biomaterial implants with the surrounding host tissue in rats, hamsters and mice. By means of intravital fluorescence microscopy, this chronic model allows for repeated analyses of various cellular, molecular and microvascular mechanisms, which are involved in the early inflammatory and angiogenic host tissue response to biomaterials during the initial 2-3 weeks after implantation. Therefore, the dorsal skinfold chamber has been broadly used during the last two decades to assess the in vivo performance of prosthetic vascular grafts, metallic implants, surgical meshes, bone substitutes, scaffolds for tissue engineering, as well as for locally or systemically applied drug delivery systems. These studies have contributed to identify basic material properties determining the biocompatibility of the implants and vascular ingrowth into their surface or internal structures. Thus, the dorsal skinfold chamber model does not only provide deep insights into the complex interactions of biomaterials with the surrounding soft tissues of the host but also represents an important tool for the future development of novel biomaterials aiming at an optimisation of their biofunctionality in clinical practice.

Role of the right dorsal anterior insula in the urge to tic in Tourette syndrome.

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Tinaz, Sule; Malone, Patrick; Hallett, Mark; Horovitz, Silvina G

2015-08-01

The mid-posterior part of the insula is involved in processing bodily sensations and urges and is activated during tic generation in Tourette syndrome. The dorsal anterior part of the insula, however, integrates sensory and emotional information with cognitive valuation and is implicated in interoception. The right dorsal anterior insula also participates in urge suppression in healthy subjects. This study examined the role of the right dorsal anterior insula in the urge to tic in Tourette syndrome. Resting-state functional magnetic resonance imaging was performed in 13 adult Tourette patients and 13 matched controls. The role of the right dorsal anterior insula within the urge-tic network was investigated using graph theory-based neural network analysis. The functional connectivity of the right dorsal anterior insula was also correlated with urge and tic severity. Even though the patients did not exhibit any overt tics, the right dorsal anterior insula demonstrated higher connectivity, especially with the frontostriatal nodes of the urge-tic network in patients compared with controls. The functional connectivity between the right dorsal anterior insula and bilateral supplementary motor area also correlated positively with urge severity in patients. These results suggest that the right dorsal anterior insula is part of the urge-tic network and could influence the urge- and tic-related cortico-striato-thalamic regions even during rest in Tourette syndrome. It might be responsible for heightened awareness of bodily sensations generating premonitory urges in Tourette syndrome. © 2015 International Parkinson and Movement Disorder Society.

Human dorsal striatum encodes prediction errors during observational learning of instrumental actions.

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Cooper, Jeffrey C; Dunne, Simon; Furey, Teresa; O'Doherty, John P

2012-01-01

The dorsal striatum plays a key role in the learning and expression of instrumental reward associations that are acquired through direct experience. However, not all learning about instrumental actions require direct experience. Instead, humans and other animals are also capable of acquiring instrumental actions by observing the experiences of others. In this study, we investigated the extent to which human dorsal striatum is involved in observational as well as experiential instrumental reward learning. Human participants were scanned with fMRI while they observed a confederate over a live video performing an instrumental conditioning task to obtain liquid juice rewards. Participants also performed a similar instrumental task for their own rewards. Using a computational model-based analysis, we found reward prediction errors in the dorsal striatum not only during the experiential learning condition but also during observational learning. These results suggest a key role for the dorsal striatum in learning instrumental associations, even when those associations are acquired purely by observing others.

Basal Cell Carcinoma of the Dorsal Hand: An Update and Comprehensive Review of the Literature.

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Loh, Tiffany Y; Rubin, Ashley G; Brian Jiang, Shang I

2016-04-01

Excessive ultraviolet radiation (UVR) exposure is the primary predisposing factor for basal cell carcinoma (BCC). However, surprisingly, BCCs occur very rarely on the dorsal hand, which is subject to intense sun exposure, and their infrequent presentation in this location suggests that other factors besides UVR may play a role in BCC pathogenesis. Because dorsal hand BCCs are uncommon, knowledge of their characteristics is limited, and more data are needed to describe their clinical presentation and treatment. To perform an updated review of the literature on the management of dorsal hand BCCs. The authors conducted a comprehensive literature review by searching the PubMed database with the key phrases "basal cell carcinoma dorsal hand," "basal cell carcinoma hand," and "basal cell carcinoma finger," and "basal cell carcinoma thumb." The authors identified 176 cases of dorsal hand BCCs in the literature, 120 of which had sufficient data for analysis. Only 4 cases were treated with Mohs micrographic surgery (MMS). The authors present 14 additional cases of dorsal hand BCCs treated with MMS. Basal cell carcinomas on the dorsal hand occur infrequently, and potential risk factors include being a male of white descent and personal history of skin cancer. Mohs micrographic surgery seems to be an effective treatment method.

Basal Cell Carcinoma of the Dorsal Foot: An Update and Comprehensive Review of the Literature.

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Loh, Tiffany Y; Rubin, Ashley G; Jiang, Shang I Brian

2017-01-01

Ultraviolet radiation is a well-known risk factor for basal cell carcinoma (BCC). Therefore, the high incidence of BCCs in sun-exposed areas such as the head and neck is unsurprising. However, unexpectedly, BCCs on the sun-protected dorsal foot have also been reported, and tumor occurrence here suggests that other factors besides ultraviolet radiation may play a role in BCC pathogenesis. Because only few dorsal foot BCCs have been reported, data on their clinical features and management are limited. To perform an updated review of the literature on clinical characteristics and treatment of dorsal foot BCCs. We conducted a comprehensive literature review by searching the PubMed database with the key phrases "basal cell carcinoma dorsal foot," "basal cell carcinoma foot," and "basal cell carcinoma toe." We identified 20 cases of dorsal foot BCCs in the literature, 17 of which had sufficient data for analysis. Only 1 case was treated with Mohs micrographic surgery. We present 8 additional cases of dorsal foot BCCs treated with Mohs micrographic surgery. Basal cell carcinomas on the dorsal foot are rare, and potential risk factors include Caucasian descent and personal history of skin cancer. Mohs micrographic surgery seems to be an effective treatment option.

Influence of early stress on social abilities and serotonergic functions across generations in mice.

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Tamara B Franklin

Full Text Available Exposure to adverse environments during early development is a known risk factor for several psychiatric conditions including antisocial behavior and personality disorders. Here, we induced social anxiety and altered social recognition memory in adult mice using unpredictable maternal separation and maternal stress during early postnatal life. We show that these social defects are not only pronounced in the animals directly subjected to stress, but are also transmitted to their offspring across two generations. The defects are associated with impaired serotonergic signaling, in particular, reduced 5HT1A receptor expression in the dorsal raphe nucleus, and increased serotonin level in a dorsal raphe projection area. These findings underscore the susceptibility of social behaviors and serotonergic pathways to early stress, and the persistence of their perturbation across generations.

Two different streams form the dorsal visual system: anatomy and functions.

Science.gov (United States)

Rizzolatti, Giacomo; Matelli, Massimo

2003-11-01

There are two radically different views on the functional role of the dorsal visual stream. One considers it as a system involved in space perception. The other is of a system that codes visual information for action organization. On the basis of new anatomical data and a reconsideration of previous functional and clinical data, we propose that the dorsal stream and its recipient parietal areas form two distinct functional systems: the dorso-dorsal stream (d-d stream) and the ventro-dorsal stream (v-d stream). The d-d stream is formed by area V6 (main d-d extrastriate visual node) and areas V6A and MIP of the superior parietal lobule. Its major functional role is the control of actions "on line". Its damage leads to optic ataxia. The v-d stream is formed by area MT (main v-d extrastriate visual node) and by the visual areas of the inferior parietal lobule. As the d-d stream, v-d stream is responsible for action organization. It, however, also plays a crucial role in space perception and action understanding. The putative mechanisms linking action and perception in the v-d stream is discussed.

Slack KNa Channels Influence Dorsal Horn Synapses and Nociceptive Behavior.

Science.gov (United States)

Evely, Katherine M; Pryce, Kerri D; Bausch, Anne E; Lukowski, Robert; Ruth, Peter; Haj-Dahmane, Samir; Bhattacharjee, Arin

2017-01-01

The sodium-activated potassium channel Slack (Kcnt1, Slo2.2) is highly expressed in dorsal root ganglion neurons where it regulates neuronal firing. Several studies have implicated the Slack channel in pain processing, but the precise mechanism or the levels within the sensory pathway where channels are involved remain unclear. Here, we furthered the behavioral characterization of Slack channel knockout mice and for the first time examined the role of Slack channels in the superficial, pain-processing lamina of the dorsal horn. We performed whole-cell recordings from spinal cord slices to examine the intrinsic and synaptic properties of putative inhibitory and excitatory lamina II interneurons. Slack channel deletion altered intrinsic properties and synaptic drive to favor an overall enhanced excitatory tone. We measured the amplitudes and paired pulse ratio of paired excitatory post-synaptic currents at primary afferent synapses evoked by electrical stimulation of the dorsal root entry zone. We found a substantial decrease in the paired pulse ratio at synapses in Slack deleted neurons compared to wildtype, indicating increased presynaptic release from primary afferents. Corroborating these data, plantar test showed Slack knockout mice have an enhanced nociceptive responsiveness to localized thermal stimuli compared to wildtype mice. Our findings suggest that Slack channels regulate synaptic transmission within the spinal cord dorsal horn and by doing so establishes the threshold for thermal nociception.

Assessing dorsal scute microchemistry for reconstruction of shortnose sturgeon life histories

Science.gov (United States)

Altenritter, Matthew E.; Kinnison, Michael T.; Zydlewski, Gayle B.; Secor, David H.; Zydlewski, Joseph D.

2015-01-01

The imperiled status of sturgeons worldwide places priority on the identification and protection of critical habitats. We assessed the micro-structural and micro-chemical scope for a novel calcified structure, dorsal scutes, to be used for reconstruction of past habitat use and group separation in shortnose sturgeon (Acipenser brevirostrum). Dorsal scutes contained a dual-layered structure composed of a thin multi-layered translucent zone lying dorsally above a thicker multi-layered zone. Banding in the thick multi-layered zone correlated strongly with pectoral fin spine annuli supporting the presence of chronological structuring that could contain a chemical record of past environmental exposure. Trace element profiles (Sr:Ca), collected using both wavelength dispersive electron microprobe analysis and laser ablation inductively coupled mass spectrometry, suggest scutes record elemental information useful for tracing transitions between freshwater and marine environments. Moreover, mirror-image like Sr:Ca profiles were observed across the dual-zone structuring of the scute that may indicate duplication of the microchemical profile in a single structure. Additional element:calcium ratios measured in natal regions of dorsal scutes (Ba:Ca, Mg:Ca) suggest the potential for further refinement of techniques for identification of river systems of natal origin. In combination, our results provide proof of concept that dorsal scutes possess the necessary properties to be used as structures for reconstructions of past habitat use in sturgeons. Importantly, scutes may be collected non-lethally and with less injury than current structures, like otoliths and fin spines, affording an opportunity for broader application of microchemical techniques.

Short-term plasticity in turtle dorsal horn neurons mediated by L-type Ca2+ channels

DEFF Research Database (Denmark)

Russo, R E; Hounsgaard, J

1994-01-01

Windup--the gradual increase of the response--of dorsal horn neurons to repeated activation of primary afferents is an elementary form of short-term plasticity that may mediate central sensitization to pain. In deep dorsal horn neurons of the turtle spinal cord in vitro we report windup of the re......Windup--the gradual increase of the response--of dorsal horn neurons to repeated activation of primary afferents is an elementary form of short-term plasticity that may mediate central sensitization to pain. In deep dorsal horn neurons of the turtle spinal cord in vitro we report windup...

Surprised at all the entropy: hippocampal, caudate and midbrain contributions to learning from prediction errors.

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Anne-Marike Schiffer

Full Text Available Influential concepts in neuroscientific research cast the brain a predictive machine that revises its predictions when they are violated by sensory input. This relates to the predictive coding account of perception, but also to learning. Learning from prediction errors has been suggested for take place in the hippocampal memory system as well as in the basal ganglia. The present fMRI study used an action-observation paradigm to investigate the contributions of the hippocampus, caudate nucleus and midbrain dopaminergic system to different types of learning: learning in the absence of prediction errors, learning from prediction errors, and responding to the accumulation of prediction errors in unpredictable stimulus configurations. We conducted analyses of the regions of interests' BOLD response towards these different types of learning, implementing a bootstrapping procedure to correct for false positives. We found both, caudate nucleus and the hippocampus to be activated by perceptual prediction errors. The hippocampal responses seemed to relate to the associative mismatch between a stored representation and current sensory input. Moreover, its response was significantly influenced by the average information, or Shannon entropy of the stimulus material. In accordance with earlier results, the habenula was activated by perceptual prediction errors. Lastly, we found that the substantia nigra was activated by the novelty of sensory input. In sum, we established that the midbrain dopaminergic system, the hippocampus, and the caudate nucleus were to different degrees significantly involved in the three different types of learning: acquisition of new information, learning from prediction errors and responding to unpredictable stimulus developments. We relate learning from perceptual prediction errors to the concept of predictive coding and related information theoretic accounts.

Surprised at all the entropy: hippocampal, caudate and midbrain contributions to learning from prediction errors.

Science.gov (United States)

Schiffer, Anne-Marike; Ahlheim, Christiane; Wurm, Moritz F; Schubotz, Ricarda I

2012-01-01

Influential concepts in neuroscientific research cast the brain a predictive machine that revises its predictions when they are violated by sensory input. This relates to the predictive coding account of perception, but also to learning. Learning from prediction errors has been suggested for take place in the hippocampal memory system as well as in the basal ganglia. The present fMRI study used an action-observation paradigm to investigate the contributions of the hippocampus, caudate nucleus and midbrain dopaminergic system to different types of learning: learning in the absence of prediction errors, learning from prediction errors, and responding to the accumulation of prediction errors in unpredictable stimulus configurations. We conducted analyses of the regions of interests' BOLD response towards these different types of learning, implementing a bootstrapping procedure to correct for false positives. We found both, caudate nucleus and the hippocampus to be activated by perceptual prediction errors. The hippocampal responses seemed to relate to the associative mismatch between a stored representation and current sensory input. Moreover, its response was significantly influenced by the average information, or Shannon entropy of the stimulus material. In accordance with earlier results, the habenula was activated by perceptual prediction errors. Lastly, we found that the substantia nigra was activated by the novelty of sensory input. In sum, we established that the midbrain dopaminergic system, the hippocampus, and the caudate nucleus were to different degrees significantly involved in the three different types of learning: acquisition of new information, learning from prediction errors and responding to unpredictable stimulus developments. We relate learning from perceptual prediction errors to the concept of predictive coding and related information theoretic accounts.

Responses of spinal dorsal horn neurons to foot movements in rats with a sprained ankle

Science.gov (United States)

Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon

2011-01-01

Acute ankle injuries are common problems and often lead to persistent pain. To investigate the underlying mechanism of ankle sprain pain, the response properties of spinal dorsal horn neurons were examined after ankle sprain. Acute ankle sprain was induced manually by overextending the ankle of a rat hindlimb in a direction of plantarflexion and inversion. The weight-bearing ratio (WBR) of the affected foot was used as an indicator of pain. Single unit activities of dorsal horn neurons in response to plantarflexion and inversion of the foot or ankle compression were recorded from the medial part of the deep dorsal horn, laminae IV-VI, in normal and ankle-sprained rats. One day after ankle sprain, rats showed significantly reduced WBRs on the affected foot, and this reduction was partially restored by systemic morphine. The majority of deep dorsal horn neurons responded to a single ankle stimulus modality. After ankle sprain, the mean evoked response rates were significantly increased, and afterdischarges were developed in recorded dorsal horn neurons. The ankle sprain-induced enhanced evoked responses were significantly reduced by morphine, which was reversed by naltrexone. The data indicate that movement-specific dorsal horn neuron responses were enhanced after ankle sprain in a morphine-dependent manner, thus suggesting that hyperactivity of dorsal horn neurons is an underlying mechanism of pain after ankle sprain. PMID:21389306

Differentiated human midbrain-derived neural progenitor cells express excitatory strychnine-sensitive glycine receptors containing α2β subunits.

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Florian Wegner

Full Text Available BACKGROUND: Human fetal midbrain-derived neural progenitor cells (NPCs may deliver a tissue source for drug screening and regenerative cell therapy to treat Parkinson's disease. While glutamate and GABA(A receptors play an important role in neurogenesis, the involvement of glycine receptors during human neurogenesis and dopaminergic differentiation as well as their molecular and functional characteristics in NPCs are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated NPCs in respect to their glycine receptor function and subunit expression using electrophysiology, calcium imaging, immunocytochemistry, and quantitative real-time PCR. Whole-cell recordings demonstrate the ability of NPCs to express functional strychnine-sensitive glycine receptors after differentiation for 3 weeks in vitro. Pharmacological and molecular analyses indicate a predominance of glycine receptor heteromers containing α2β subunits. Intracellular calcium measurements of differentiated NPCs suggest that glycine evokes depolarisations mediated by strychnine-sensitive glycine receptors and not by D-serine-sensitive excitatory glycine receptors. Culturing NPCs with additional glycine, the glycine-receptor antagonist strychnine, or the Na(+-K(+-Cl(- co-transporter 1 (NKCC1-inhibitor bumetanide did not significantly influence cell proliferation and differentiation in vitro. CONCLUSIONS/SIGNIFICANCE: These data indicate that NPCs derived from human fetal midbrain tissue acquire essential glycine receptor properties during neuronal maturation. However, glycine receptors seem to have a limited functional impact on neurogenesis and dopaminergic differentiation of NPCs in vitro.

Lipoma of the midbrain: post-mortem finding in a patient with breast cancer

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Verônica Maia Gouvea

1989-09-01

Full Text Available Intracranial lipomas are rare, usually do not have clinical expression and are located mare frequently in the corpus callosum. Other locations include the spinal cord, midbrain tectum, superior vermis, tuber cinereum, infundibulum and more rarely cerebellopontine angle, hypothalamus, superior medullary velum and insula. We report the case of a lipoma of the left inferior colliculus which was a post-mortem finding in a woman who died of breast cancer. Although there are reports of intracranial lipomas in patients with malignant tumors there is no explanation for the co-existence of the two tumors. The present tumor also includes a segment of a nerve which is not uncommon, but a less common finding was the presence of nests of Schwann cells within it, shown by immunohistochemistry.

Dorsal onlay vaginal graft urethroplasty for female urethral stricture

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Manmeet Singh

2013-01-01

Full Text Available Introduction: Female urethral stricture is an underdiagnosed and overlooked cause of female bladder outlet obstruction. The possible etiologies may be infection, prior dilation, difficult catheterization with subsequent fibrosis, urethral surgery, trauma, or idiopathic. We present our technique and results of dorsal onlay full thickness vaginal graft urethroplasty for female urethral stricture. Materials and Methods: A retrospective review was performed on 16 female patients with mid-urethral stricture who underwent dorsal onlay vaginal graft urethroplasty from January 2007 to June 2011.Of these, 13 patients had previously undergone multiple Hegar dilatations, three had previous internal urethrotomies. The preoperative work up included detailed voiding history, local examination, uroflowmetry, calibration, and micturating cystourethrogram. Results: All patients had mid-urethral stricture. Mean age was 47.5 years. Mean Q max improved from 6.2 to 27.6 ml/s. Mean residual volume decreased from 160 to 20 ml. Mean duration of follow-up was 24.5 months (6 months to 3 years. Only one patient required self-calibration for 6 months after which her stricture stabilized. None of the patient was incontinent. Conclusion: Dorsal vaginal onlay graft urethroplasty could be considered as an effective way to treat female urethral stricture.

Altered sensorimotor activation patterns in idiopathic dystonia-an activation likelihood estimation meta-analysis of functional brain imaging studies

DEFF Research Database (Denmark)

Løkkegaard, Annemette; Herz, Damian M; Haagensen, Brian Numelin

2016-01-01

Dystonia is characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements or postures. Functional neuroimaging studies have yielded abnormal task-related sensorimotor activation in dystonia, but the results appear to be rather variable across studies....... Further, study size was usually small including different types of dystonia. Here we performed an activation likelihood estimation (ALE) meta-analysis of functional neuroimaging studies in patients with primary dystonia to test for convergence of dystonia-related alterations in task-related activity...... postcentral gyrus, right superior temporal gyrus and dorsal midbrain. Apart from the midbrain cluster, all between-group differences in task-related activity were retrieved in a sub-analysis including only the 14 studies on patients with focal dystonia. For focal dystonia, an additional cluster of increased...

Calcium activity of upper thoracic dorsal root ganglion neurons in zucker diabetic Fatty rats

DEFF Research Database (Denmark)

Ghorbani, Marie Louise; Nyborg, Niels C B; Fjalland, Bjarne

2013-01-01

The aim of the present study was to examine the calcium activity of C8-T5 dorsal root ganglion (DRG) neurons from Zucker diabetic fatty rats. In total, 8 diabetic ZDF fatty animals and 8 age-matched control ZDF lean rats were employed in the study. C8-T5 dorsal root ganglia were isolated bilatera......The aim of the present study was to examine the calcium activity of C8-T5 dorsal root ganglion (DRG) neurons from Zucker diabetic fatty rats. In total, 8 diabetic ZDF fatty animals and 8 age-matched control ZDF lean rats were employed in the study. C8-T5 dorsal root ganglia were isolated...... in calcium activity of the DRG neurons were found, potentially indicating altered neuronal responses during myocardial ischemia....

A new class of ubiquitin extension proteins secreted by the dorsal pharyngeal gland in plant parasitic cyst nematodes.

Science.gov (United States)

Tytgat, Tom; Vanholme, Bartel; De Meutter, Jan; Claeys, Myriam; Couvreur, Marjolein; Vanhoutte, Isabelle; Gheysen, Greetje; Van Criekinge, Wim; Borgonie, Gaetan; Coomans, August; Gheysen, Godelieve

2004-08-01

By performing cDNA AFLP on pre- and early parasitic juveniles, we identified genes encoding a novel type of ubiquitin extension proteins secreted by the dorsal pharyngeal gland in the cyst nematode Heterodera schachtii. The proteins consist of three domains, a signal peptide for secretion, a mono-ubiquitin domain, and a short C-terminal positively charged domain. A gfp-fusion of this protein is targeted to the nucleolus in tobacco BY-2 cells. We hypothesize that the C-terminal peptide might have a regulatory function during syncytium formation in plant roots.

Individual differences in the motivation to communicate relate to levels of midbrain and striatal catecholamine markers in male European starlings

OpenAIRE

Heimovics, Sarah A; Salvante, Katrina G; Sockman, Keith W; Riters, Lauren V

2011-01-01

Individuals display dramatic differences in social communication even within similar social contexts. Across vertebrates dopaminergic projections from the ventral tegmental area (VTA) and midbrain central gray (GCt) strongly influence motivated, reward-directed behaviors. Norepinephrine is also rich in these areas and may alter dopamine neuronal activity. The present study was designed to provide insight into the roles of dopamine and norepinephrine in VTA and GCt and their efferent striatal ...

A case of dorsal oblique fingertip amputation.

Science.gov (United States)

Takeda, Shinsuke; Tatebe, Masahiro; Morita, Akimasa; Yoneda, Hidemasa; Iwatsuki, Katsuyuki; Hirata, Hitoshi

2017-01-01

This study reports successful finger replantation in a patient with a dorsal oblique fingertip amputation. When repairing this unique type of injury, an evaluation of the remaining vessels is more useful for successful replantation than the anatomical zone classification. We propose that Kasai's classification is appropriate for guiding treatment.

Dorsal stream involvement in recognition of objects with transient onset but not with ramped onset

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Lourenco Tomas

2011-08-01

Full Text Available Abstract Background Although the ventral visual stream is understood to be responsible for object recognition, it has been proposed that the dorsal stream may contribute to object recognition by rapidly activating parietal attention mechanisms, prior to ventral stream object processing. Methods To investigate the relative contribution of the dorsal visual stream to object recognition a group of tertiary students were divided into good and poor motion coherence groups and assessed on tasks classically assumed to rely on ventral stream processing. Participants were required to identify simple line drawings in two tasks, one where objects were presented abruptly for 50 ms followed by a white-noise mask, the other where contrast was linearly ramped on and off over 325 ms and replaced with a mask. Results Although both groups only differed in motion coherence performance (a dorsal stream measure, the good motion coherence group showed superior contrast sensitivity for object recognition on the abrupt, but not the ramped presentation tasks. Conclusions We propose that abrupt presentation of objects activated attention mechanisms fed by the dorsal stream, whereas the ramped presentation had reduced transience and thus did not activate dorsal attention mechanisms as well. The results suggest that rapid dorsal stream activation may be required to assist with ventral stream object processing.

Diagnosis of dorsal inter osseous pseudotumours by magnetic resonance imaging

International Nuclear Information System (INIS)

Peh, W.C.G.; Wong, L.L.S.; Ip, W.Y.

1999-01-01

Two middle-aged-patients each presenting with a progressively enlarging mass in the first dorsal web space of their hands are reported. Magnetic resonance imaging (MRI) demonstrated the cause to be a hypertrophic first dorsal inter osseous muscle, with normal T1, T2 and post-gadopentetate dimeglumine signal characteristics. The ability of MRI to diagnose anatomical variants of hand muscles is important in the clinical management of patients with these pseudotumours. The usefulness of magnetic resonance imaging (MRI) in evaluation of soft tissue tumours of the musculoskeletal system is now widely accepted. Its ability to maximize contrast between tumour and adjacent normal tissue in a multiplanar manner makes it the imaging modality of choice in pre-operative staging of soft tissue masses. In the hand and wrist, where benign tumours predominate, MRI may provide a specific diagnosis. We describe two cases in which MRI demonstrated the cause of a hand pseudotumour to be due to hypertrophy of the first dorsal inter osseous muscle. Copyright (1999) Blackwell Science Pty Ltd

Diagnosis of dorsal inter osseous pseudotumours by magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Peh, W.C.G.; Wong, L.L.S. [The University of Hong Kong, Queen Mary Hospital, (Hong Kong). Hand Surgery Division, Department of Diagnotic Radiology; Ip, W.Y. [The University of Hong Kong, Queen Mary Hospital, (Hong Kong). Hand Surgery Division, Department of Orthopaedic Surgery

1999-08-01

Two middle-aged-patients each presenting with a progressively enlarging mass in the first dorsal web space of their hands are reported. Magnetic resonance imaging (MRI) demonstrated the cause to be a hypertrophic first dorsal inter osseous muscle, with normal T1, T2 and post-gadopentetate dimeglumine signal characteristics. The ability of MRI to diagnose anatomical variants of hand muscles is important in the clinical management of patients with these pseudotumours. The usefulness of magnetic resonance imaging (MRI) in evaluation of soft tissue tumours of the musculoskeletal system is now widely accepted. Its ability to maximize contrast between tumour and adjacent normal tissue in a multiplanar manner makes it the imaging modality of choice in pre-operative staging of soft tissue masses. In the hand and wrist, where benign tumours predominate, MRI may provide a specific diagnosis. We describe two cases in which MRI demonstrated the cause of a hand pseudotumour to be due to hypertrophy of the first dorsal inter osseous muscle. Copyright (1999) Blackwell Science Pty Ltd 20 refs., 3 figs.

Discrimination of communication vocalizations by single neurons and groups of neurons in the auditory midbrain.

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Schneider, David M; Woolley, Sarah M N

2010-06-01

Many social animals including songbirds use communication vocalizations for individual recognition. The perception of vocalizations depends on the encoding of complex sounds by neurons in the ascending auditory system, each of which is tuned to a particular subset of acoustic features. Here, we examined how well the responses of single auditory neurons could be used to discriminate among bird songs and we compared discriminability to spectrotemporal tuning. We then used biologically realistic models of pooled neural responses to test whether the responses of groups of neurons discriminated among songs better than the responses of single neurons and whether discrimination by groups of neurons was related to spectrotemporal tuning and trial-to-trial response variability. The responses of single auditory midbrain neurons could be used to discriminate among vocalizations with a wide range of abilities, ranging from chance to 100%. The ability to discriminate among songs using single neuron responses was not correlated with spectrotemporal tuning. Pooling the responses of pairs of neurons generally led to better discrimination than the average of the two inputs and the most discriminating input. Pooling the responses of three to five single neurons continued to improve neural discrimination. The increase in discriminability was largest for groups of neurons with similar spectrotemporal tuning. Further, we found that groups of neurons with correlated spike trains achieved the largest gains in discriminability. We simulated neurons with varying levels of temporal precision and measured the discriminability of responses from single simulated neurons and groups of simulated neurons. Simulated neurons with biologically observed levels of temporal precision benefited more from pooling correlated inputs than did neurons with highly precise or imprecise spike trains. These findings suggest that pooling correlated neural responses with the levels of precision observed in the

Persistent dorsal ophthalmic artery arising from the internal carotid artery: Report of three cases

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Shin, Jae Hwan; Lee, Ghi Jai; Shim, Jae Chan; Lee, Kyoung Eun; Kim, Ho Kyun; Suh, Jung Ho [Dept. of Radiology, Seoul Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

2016-12-15

Normally, the ophthalmic artery (OA) arises from the supraclinoid segment of the internal carotid artery (ICA) and enters the orbit via the optic canal. A persistent dorsal OA is a rare variation that originates from the cavernous segment of the ICA and enters the orbit via the superior orbital fissure. To the best of our knowledge, persistent dorsal OA has not been described in the Korean literature. In this paper, we report three cases of persistent dorsal OA with review of the literature on embryogenesis and other origins of the OA.

Dorsal onlay graft bulbar urethroplasty using buccal mucosa

African Journals Online (AJOL)

G. Barbagli

2015-12-02

Dec 2, 2015 ... promote the transformation of the urethral mucosa plate into a tube, according to ... Allen stirrups and sequential inflatable compression sleeves. Figure 2 .... the ventral, dorsal or lateral surface of the urethra, we investigated if.

Investigating category- and shape-selective neural processing in ventral and dorsal visual stream under interocular suppression.

Science.gov (United States)

Ludwig, Karin; Kathmann, Norbert; Sterzer, Philipp; Hesselmann, Guido

2015-01-01

Recent behavioral and neuroimaging studies using continuous flash suppression (CFS) have suggested that action-related processing in the dorsal visual stream might be independent of perceptual awareness, in line with the "vision-for-perception" versus "vision-for-action" distinction of the influential dual-stream theory. It remains controversial if evidence suggesting exclusive dorsal stream processing of tool stimuli under CFS can be explained by their elongated shape alone or by action-relevant category representations in dorsal visual cortex. To approach this question, we investigated category- and shape-selective functional magnetic resonance imaging-blood-oxygen level-dependent responses in both visual streams using images of faces and tools. Multivariate pattern analysis showed enhanced decoding of elongated relative to non-elongated tools, both in the ventral and dorsal visual stream. The second aim of our study was to investigate whether the depth of interocular suppression might differentially affect processing in dorsal and ventral areas. However, parametric modulation of suppression depth by varying the CFS mask contrast did not yield any evidence for differential modulation of category-selective activity. Together, our data provide evidence for shape-selective processing under CFS in both dorsal and ventral stream areas and, therefore, do not support the notion that dorsal "vision-for-action" processing is exclusively preserved under interocular suppression. © 2014 Wiley Periodicals, Inc.

A case of dorsal oblique fingertip amputation

OpenAIRE

Takeda, Shinsuke; Tatebe, Masahiro; Morita, Akimasa; Yoneda, Hidemasa; Iwatsuki, Katsuyuki; Hirata, Hitoshi

2017-01-01

Abstract This study reports successful finger replantation in a patient with a dorsal oblique fingertip amputation. When repairing this unique type of injury, an evaluation of the remaining vessels is more useful for successful replantation than the anatomical zone classification. We propose that Kasai?s classification is appropriate for guiding treatment.

Bulbar urethroplasty using the dorsal approach: current techniques

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Barbagli Guido

2003-01-01

Full Text Available INTRODUCTION: The use of flaps or grafts is mandatory in patients with longer and complex strictures. In 1995-96 we described a new dorsal onlay graft urethroplasty. Over time, our original technique was better defined and changed. Now this procedure (also named Barbagli technique has been greeted with a fair amount of enthusiasm in Europe and in the United States. SURGICAL TECHNIQUE: The patient is placed in normal lithotomy position, and a midline perineo-scrotal incision is made. The bulbar urethra is then free from the bulbo-cavernous muscles, and is dissected from the corpora cavernosa. The urethra is completely mobilized from the corpora cavernosa, it is rotated 180 degrees, and is incised along its dorsal surface. The graft (preputial skin or buccal mucosa or the flap is fixed and quilted to the tunica albuginea of the corporal bodies. The right mucosal margin of the opened urethra is sutured to the right side of the patch-graft. The urethra is rotated back into its original position. The left urethral margin is sutured to the left side of the patch graft and to the corporal bodies, and the grafted area is entirely covered by the urethral plate. The bulbo-cavernous muscles are approximated over the grafted area. A 16F silicone Foley catheter is left in place. COMMENTS: Dorsal onlay graft urethroplasty is a versatile procedure that may be combined with various substitute materials like preputial skin, buccal mucosa grafts or pedicled flaps.

Ventral medullary neurones excited from the hypothalamic and mid-brain defence areas.

Science.gov (United States)

Hilton, S M; Smith, P R

1984-07-01

In cats anaesthetised with chloralose, the ventral medulla was explored in and around the strip previously identified as the location of the efferent pathway from the hypothalamic and mid-brain defence areas to the spinal cord, in a search for neurones excited by electrical stimulation of the defence areas. Such units were found mostly in the caudal part of this strip, at a depth of not more than 500 microns from the surface. Nearly all were located in the ventral part of nucleus paragigantocellularis lateralis (PGL) at the level of the rostral pole of the inferior olive. There was evidence of temporal and spatial facilitation, indicating a convergent excitatory input from the defence areas onto neurones in PGL. This is consistent with earlier evidence of a synaptic relay in the efferent pathway at this site. When the pathway is blocked at this site, arterial blood pressure falls profoundly, so activity in these neurones may be essential for the normal level of sympathetic nerve activity.

Midbrain Gene Screening Identifies a New Mesoaccumbal Glutamatergic Pathway and a Marker for Dopamine Cells Neuroprotected in Parkinson?s Disease

OpenAIRE

Viereckel, Thomas; Dumas, Sylvie; Smith-Anttila, Casey J. A.; Vlcek, Bianca; Bimpisidis, Zisis; Lagerstr?m, Malin C.; Konradsson-Geuken, ?sa; Wall?n-Mackenzie, ?sa

2016-01-01

The ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) of the midbrain are associated with Parkinson's disease (PD), schizophrenia, mood disorders and addiction. Based on the recently unraveled heterogeneity within the VTA and SNc, where glutamate, GABA and co-releasing neurons have been found to co-exist with the classical dopamine neurons, there is a compelling need for identification of gene expression patterns that represent this heterogeneity and that are of value for ...

Sp6 and Sp8 Transcription Factors Control AER Formation and Dorsal-Ventral Patterning in Limb Development

Science.gov (United States)

Haro, Endika; Delgado, Irene; Junco, Marisa; Yamada, Yoshihiko; Mansouri, Ahmed; Oberg, Kerby C.; Ros, Marian A.

2014-01-01

The formation and maintenance of the apical ectodermal ridge (AER) is critical for the outgrowth and patterning of the vertebrate limb. The induction of the AER is a complex process that relies on integrated interactions among the Fgf, Wnt, and Bmp signaling pathways that operate within the ectoderm and between the ectoderm and the mesoderm of the early limb bud. The transcription factors Sp6 and Sp8 are expressed in the limb ectoderm and AER during limb development. Sp6 mutant mice display a mild syndactyly phenotype while Sp8 mutants exhibit severe limb truncations. Both mutants show defects in AER maturation and in dorsal-ventral patterning. To gain further insights into the role Sp6 and Sp8 play in limb development, we have produced mice lacking both Sp6 and Sp8 activity in the limb ectoderm. Remarkably, the elimination or significant reduction in Sp6;Sp8 gene dosage leads to tetra-amelia; initial budding occurs, but neither Fgf8 nor En1 are activated. Mutants bearing a single functional allele of Sp8 (Sp6−/−;Sp8+/−) exhibit a split-hand/foot malformation phenotype with double dorsal digit tips probably due to an irregular and immature AER that is not maintained in the center of the bud and on the abnormal expansion of Wnt7a expression to the ventral ectoderm. Our data are compatible with Sp6 and Sp8 working together and in a dose-dependent manner as indispensable mediators of Wnt/βcatenin and Bmp signaling in the limb ectoderm. We suggest that the function of these factors links proximal-distal and dorsal-ventral patterning. PMID:25166858

A novel function for the IκB inhibitor Cactus in promoting Dorsal nuclear localization and activity in the Drosophila embryo.

Science.gov (United States)

Cardoso, Maira Arruda; Fontenele, Marcio; Lim, Bomyi; Bisch, Paulo Mascarello; Shvartsman, Stanislav Y; Araujo, Helena Marcolla

2017-08-15

The evolutionarily conserved Toll signaling pathway controls innate immunity across phyla and embryonic patterning in insects. In the Drosophila embryo, Toll is required to establish gene expression domains along the dorsal-ventral axis. Pathway activation induces degradation of the IκB inhibitor Cactus, resulting in a ventral-to-dorsal nuclear gradient of the NFκB effector Dorsal. Here, we investigate how cactus modulates Toll signals through its effects on the Dorsal gradient and on Dorsal target genes. Quantitative analysis using a series of loss- and gain-of-function conditions shows that the ventral and lateral aspects of the Dorsal gradient can behave differently with respect to Cactus fluctuations. In lateral and dorsal embryo domains, loss of Cactus allows more Dorsal to translocate to the nucleus. Unexpectedly, cactus loss-of-function alleles decrease Dorsal nuclear localization ventrally, where Toll signals are high. Overexpression analysis suggests that this ability of Cactus to enhance Toll stems from the mobilization of a free Cactus pool induced by the Calpain A protease. These results indicate that Cactus acts to bolster Dorsal activation, in addition to its role as a NFκB inhibitor, ensuring a correct response to Toll signals. © 2017. Published by The Company of Biologists Ltd.

Monosynaptic connections between primary afferents and giant neurons in the turtle spinal dorsal horn

DEFF Research Database (Denmark)

Fernández, A; Radmilovich, M; Russo, R E

1996-01-01

This paper reports the occurrence of monosynaptic connections between dorsal root afferents and a distinct cell type-the giant neuron-deep in the dorsal horn of the turtle spinal cord. Light microscope studies combining Nissl stain and transganglionic HRP-labeling of the primary afferents have...

Anatomy and muscle activity of the dorsal fins in bamboo sharks and spiny dogfish during turning maneuvers.

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Maia, Anabela; Wilga, Cheryl D

2013-11-01

Stability and procured instability characterize two opposing types of swimming, steady and maneuvering, respectively. Fins can be used to manipulate flow to adjust stability during swimming maneuvers either actively using muscle control or passively by structural control. The function of the dorsal fins during turning maneuvering in two shark species with different swimming modes is investigated here using musculoskeletal anatomy and muscle function. White-spotted bamboo sharks are a benthic species that inhabits complex reef habitats and thus have high requirements for maneuverability. Spiny dogfish occupy a variety of coastal and continental shelf habitats and spend relatively more time cruising in open water. These species differ in dorsal fin morphology and fin position along the body. Bamboo sharks have a larger second dorsal fin area and proportionally more muscle insertion into both dorsal fins. The basal and radial pterygiophores are plate-like structures in spiny dogfish and are nearly indistinguishable from one another. In contrast, bamboo sharks lack basal pterygiophores, while the radial pterygiophores form two rows of elongated rectangular elements that articulate with one another. The dorsal fin muscles are composed of a large muscle mass that extends over the ceratotrichia overlying the radials in spiny dogfish. However, in bamboo sharks, the muscle mass is divided into multiple distinct muscles that insert onto the ceratotrichia. During turning maneuvers, the dorsal fin muscles are active in both species with no differences in onset between fin sides. Spiny dogfish have longer burst durations on the outer fin side, which is consistent with opposing resistance to the medium. In bamboo sharks, bilateral activation of the dorsal in muscles could also be stiffening the fin throughout the turn. Thus, dogfish sharks passively stiffen the dorsal fin structurally and functionally, while bamboo sharks have more flexible dorsal fins, which result from a

Posture And Dorsal Shape At A Sitted Workstation

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Lepoutre, F. X.; Cloup, P.; Guerra, T. M.

1986-07-01

The ergonomic analysis of a control or a supervision workstation for a vehicle or a process, necessitates to take into account the biomecanical visuo-postural system. The measurements, which are necessary to do, must give informations about the spatial direction of the limbs, the dorsal shape, eventually the eyes direction, and the postural evolution during the working time. More, the smallness of the work station, the backrest and sometime a vibratory environment made use specific, strong and small devices wich do not disturb the operator. The measurement system which we propose is made of an optical device. This system is studied in relation with the french "Institute de Recherche pour les Transports" for an ergonomic analysis of a truck cabin. The optical device consists on placing on the body of the driver on particular places materializing specially members and trunck joint points, some drops which reflect the infra-red raies coming from a specific light. Several cameras whose relative positions depend on the experiment site, transmit video signals to the associated treatment systems which extract the coordinates (Xi, Yi) of each drop in the observation scope of any camera. By regrouping the informations obtained from every view, it is possible to obtain the spatial drop position and then to restore the individual's posture in three dimensions. Therefore, this device doesn't enable us, in consideration of the backrest, to analyse the dorsal posture, which is important with regard to dorsal pains frequency. For that reason, we complete the measurements by using a "curvometer". This device consists of a flexible stick fixed upon the individual back with elastic belts, whose distorsions (curvature in m-1) are measured, in the individual's sagittal plane, with 4 strain gauges pairs; located approximately at the level of vertebra D1, D6, D10 and L3. A fifth measurement, concerning the inclination (in degree) of the lower part of the stick, makes it is possible to

Dorsal Branches of Abdominal Aorta in the Rabbit and the European Hare

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Flešárová S.

2016-06-01

Full Text Available The aim of this study was to describe the anatomical arrangement of the branches arising from the dorsal surface of the aorta abdominalis in the rabbit and the hare. The study was carried out on ten adult rabbits and ten adult European hares using the corrosion technique. After the euthanasia, the vascular network was perfused with saline. After polymerization of the casting medium, the maceration was carried out in a KOH solution. We found different variations in; the number of arteries, level of their origin and arrangement. The aa. lumbales of the same level arose by means of a common trunk or their origin was independent. The aa. lumbales VI or aa. lumbales VI et VII originated also from the a. sacralis mediana. By aa. lumbales we found an important interspecies difference in; number, diameter, ramification and density of dorsal branches, which are designated for the dorsal muscles of the body stem. All listed parameters of branches were higher in the hare. This anatomical arrangement of dorsal branches is adapted to the higher movement activity of the hare. According to our results, it can be concluded that the anatomical arrangement of the branches of the aorta abdominalis shows a higher number of variations in the domesticated rabbit in comparison with the hare.

Dorsal free graft urethroplasty for urethral stricture by ventral sagittal urethrotomy approach.

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Asopa, H S; Garg, M; Singhal, G G; Singh, L; Asopa, J; Nischal, A

2001-11-01

To explore the feasibility of applying a dorsal free graft to treat urethral stricture by the ventral sagittal urethrotomy approach without mobilizing the urethra. Twelve patients with long or multiple strictures of the anterior urethra were treated by a dorsal free full-thickness preputial or buccal mucosa graft. The urethra was not separated from the corporal bodies and was opened in the midline over the stricture. The floor of the urethra was incised, and an elliptical raw area was created over the tunica on which a free full-thickness graft of preputial or buccal mucosa was secured. The urethra was retubularized in one stage. After a follow-up of 8 to 40 months, one recurrence developed and required dilation. The ventral sagittal urethrotomy approach for dorsal free graft urethroplasty is not only feasible and successful, but is easy to perform.

Dorsal onlay lingual mucosal graft urethroplasty for urethral strictures in women.

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Sharma, Girish K; Pandey, Ashwani; Bansal, Harbans; Swain, Sameer; Das, Suren K; Trivedi, Sameer; Dwivedi, Udai S; Singh, Pratap B

2010-05-01

To describe the technique and results of dorsal onlay lingual mucosal graft (LMG) urethroplasty for the definitive management of urethral strictures in women. In all, 15 women (mean age 42 years) with a history suggestive of urethral stricture who had undergone multiple urethral dilatations and/or urethrotomy were selected for dorsal onlay LMG urethroplasty after thorough evaluation, from October 2006 to March 2008. After a suprameatal inverted-U incision, the dorsal aspect of the urethra was dissected and urethrotomy was done at the 12 o'clock position across the strictured segment. Tailored LMG harvested from the ventrolateral aspect of the tongue was then sutured to the urethrotomy wound over an 18 F silicone catheter. The preoperative mean maximum urinary flow rate of 7.2 mL/s increased to 29.87 mL/s, 26.95 mL/s and 26.86 mL/s with a 'normal' flow rate curve at 3, 6 and 12 months follow-up, respectively. One patient at the 3-month follow-up had submeatal stenosis and required urethral dilatation thrice at monthly intervals. At the 1-year follow-up, none of the present patients had any neurosensory complications, urinary incontinence, or long-term functional/aesthetic complication at the donor site. LMG urethroplasty using the dorsal onlay technique should be offered for correction of persistent female urethral stricture as it provides a simple, safe and effective approach with durable results.

Functional and ultrastructural neuroanatomy of interactive intratectal/tectonigral mesencephalic opioid inhibitory links and nigrotectal GABAergic pathways: involvement of GABAA and mu1-opioid receptors in the modulation of panic-like reactions elicited by electrical stimulation of the dorsal midbrain.

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Ribeiro, S J; Ciscato, J G; de Oliveira, R; de Oliveira, R C; D'Angelo-Dias, R; Carvalho, A D; Felippotti, T T; Rebouças, E C C; Castellan-Baldan, L; Hoffmann, A; Corrêa, S A L; Moreira, J E; Coimbra, N C

2005-12-01

In the present study, the functional neuroanatomy of nigrotectal-tectonigral pathways as well as the effects of central administration of opioid antagonists on aversive stimuli-induced responses elicited by electrical stimulation of the midbrain tectum were determined. Central microinjections of naloxonazine, a selective mu(1)-opiod receptor antagonist, in the mesencephalic tectum (MT) caused a significant increase in the escape thresholds elicited by local electrical stimulation. Furthermore, either naltrexone or naloxonazine microinjected in the substantia nigra, pars reticulata (SNpr), caused a significant increase in the defensive thresholds elicited by electrical stimulation of the continuum comprised by dorsolateral aspects of the periaqueductal gray matter (dlPAG) and deep layers of the superior colliculus (dlSC), as compared with controls. These findings suggest an opioid modulation of GABAergic inhibitory inputs controlling the defensive behavior elicited by MT stimulation, in cranial aspects. In fact, iontophoretic microinjections of the neurotracer biodextran into the SNpr, a mesencephalic structure rich in GABA-containing neurons, show outputs to neural substrate of the dlSC/dlPAG involved with the generation and organization of fear- and panic-like reactions. Neurochemical lesion of the nigrotectal pathways increased the sensitivity of the MT to electrical (at alertness, freezing and escape thresholds) and chemical (blockade of GABA(A) receptors) stimulation, suggesting a tonic modulatory effect of the nigrotectal GABAergic outputs on the neural networks of the MT involved with the organization of the defensive behavior and panic-like reactions. Labeled neurons of the midbrain tectum send inputs with varicosities to ipsi and contralateral dlSC/dlPAG and ipsilateral substantia nigra, pars reticulata and compacta, in which the anterograde and retrograde tracing from a single injection indicates that the substantia nigra has reciprocal connections with

Shape representations in the primate dorsal visual stream

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Tom eTheys

2015-04-01

Full Text Available The primate visual system extracts object shape information for object recognition in the ventral visual stream. Recent research has demonstrated that object shape is also processed in the dorsal visual stream, which is specialized for spatial vision and the planning of actions. A number of studies have investigated the coding of 2D shape in the anterior intraparietal area (AIP, one of the end-stage areas of the dorsal stream which has been implicated in the extraction of affordances for the purpose of grasping. These findings challenge the current understanding of area AIP as a critical stage in the dorsal stream for the extraction of object affordances. The representation of three-dimensional (3D shape has been studied in two interconnected areas known to be critical for object grasping: area AIP and area F5a in the ventral premotor cortex (PMv, to which AIP projects. In both areas neurons respond selectively to 3D shape defined by binocular disparity, but the latency of the neural selectivity is approximately 10 ms longer in F5a compared to AIP, consistent with its higher position in the hierarchy of cortical areas. Furthermore F5a neurons were more sensitive to small amplitudes of 3D curvature and could detect subtle differences in 3D structure more reliably than AIP neurons. In both areas, 3D-shape selective neurons were co-localized with neurons showing motor-related activity during object grasping in the dark, indicating a close convergence of visual and motor information on the same clusters of neurons.

Morphological development of Anchoviella vaillanti (Steindachner, 1908 (Clupeiformes: Engraulidae larvae and early juveniles

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Anailza Cristina G. da Silva

Full Text Available The considerable similarity in the early life stages of different fish species makes egg and larvae identification in fishery biology and ichthyoplankton surveys a difficult task. Knowledge on early larval development of morphologically similar taxa and species-rich orders, such as Clupeiformes, mainly in the Neotropical fresh waters is rather limited. The aim of the present study was to describe morphological and meristic aspects of the larvae and early juveniles of Anchoviella vaillanti, an endemic species of the São Francisco River basin in Brazil. The characterization was based on an ontogenetic series of 132 individuals (1.3-51.0 mm SL. In the larval period, body varies from elongated to very elongated and the head is small, which is typical of Clupeiformes. The finfold is present beginning in the yolk-sac stage, when larvae have a large yolk sac, until the flexion stage. Pectoral fin buds are the first to form during the preflexion stage, when dorsal- and anal-fin pterygiophores and hypural bones are first visible. The total vertebra count ranges from 36 to 39 and the myomere number ranges from 31 to 45. Complete fin formation obeys the following sequence: anal and dorsal fins during flexion stage; and pectoral, pelvic and caudal fins during postflexion stage. Despite being the only freshwater clupeiform representative in the São Francisco River, A. vaillanti may occur sympatrically with A. lepidentostole in the lower stretches of the river basin. Although early larvae characteristics of A. lepidentostole are not known, its late larvae and early juveniles may be distinguished from those of A. vaillanti, by the higher number of dorsal-fin rays (15 or 16 vs. 12 or 13 in A. vaillanti, higher total vertebra count (40 vs. 37 to 40 and shorter pre-pectoral length (14 to 16 vs. 22.8 to 28.9% SL.

Right dorsal colon ultrasonography in normal adult ponies and miniature horses

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Zak, Agnieszka; Baron, Monika; Cylna, Marta; Borowicz, Hieronim

2017-01-01

The aim of this study was to determine the normal location, wall thickness and motility of the right dorsal colon in adult ponies and miniature horses. The abdominal ultrasonography examination was performed in a study group consisting of 23 ponies and miniature horses and in a control group comprising ten Thoroughbred horses. The procedure was performed in unsedated standing animals. The location and the thickness of the right dorsal colonic wall was examined on the right side of the abdomen between the 10th and the 14th intercostal space. The contractility was recorded in the 12th intercostal space. A comparative analysis between the study group and control group was carried out using the Student’s t-test. Pearson’s linear correlation coefficient was used to calculate the correlation between the thickness of the colonic wall as well as the number of peristaltic movements and age, wither height and body mass of the animals. The right dorsal colon was identified in all the horses in the 12th intercostal space. In all the intercostal spaces the mean ± standard deviation (SD) wall thickness of the right dorsal colon was 0.27 ± 0.03 cm in the horses from the study group and 0.37 ± 0.03 cm in the control horses. The mean number of peristaltic contractions was 4.05 ± 1.07 per minute in the animals from the study group and 1.7 ± 0.46 contractions per minute in the control group. The values of the ultrasonographic wall thickness and peristaltic motility in small breed horses in the present study were different from the values obtained for large breed horses. The study also found that the right dorsal colon in small breed horses is physiologically located in the 12th intercostal space. This suggests that different reference values should be used in small horse breeds when performing an ultrasound examination. PMID:29065146

Dorsal column sensory axons degenerate due to impaired microvascular perfusion after spinal cord injury in rats

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Muradov, Johongir M.; Ewan, Eric E.; Hagg, Theo

2013-01-01

The mechanisms contributing to axon loss after spinal cord injury (SCI) are largely unknown but may involve microvascular loss as we have previously suggested. Here, we used a mild contusive injury (120 kdyn IH impactor) at T9 in rats focusing on ascending primary sensory dorsal column axons, anterogradely traced from the sciatic nerves. The injury caused a rapid and progressive loss of dorsal column microvasculature and oligodendrocytes at the injury site and penumbra and a ~70% loss of the sensory axons, by 24 hours. To model the microvascular loss, focal ischemia of the T9 dorsal columns was achieved via phototoxic activation of intravenously injected rose bengal. This caused an ~53% loss of sensory axons and an ~80% loss of dorsal column oligodendrocytes by 24 hours. Axon loss correlated with the extent and axial length of microvessel and oligodendrocyte loss along the dorsal column. To determine if oligodendrocyte loss contributes to axon loss, the glial toxin ethidium bromide (EB; 0.3 µg/µl) was microinjected into the T9 dorsal columns, and resulted in an ~88% loss of dorsal column oligodendrocytes and an ~56% loss of sensory axons after 72 hours. EB also caused an ~72% loss of microvessels. Lower concentrations of EB resulted in less axon, oligodendrocyte and microvessel loss, which were highly correlated (R2 = 0.81). These data suggest that focal spinal cord ischemia causes both oligodendrocyte and axon degeneration, which are perhaps linked. Importantly, they highlight the need of limiting the penumbral spread of ischemia and oligodendrocyte loss after SCI in order to protect axons. PMID:23978615

Rare patterns of dorsal puncture in Pterostichus oblongopunctatus (Coleoptera: Carabidae

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Axel Schwerk

2018-04-01

Full Text Available Background The carabid beetle species Pterostichus oblongopunctatus is common in different types of forests in Poland and Europe. With respect to this species, some unclarities exist concerning the morphological feature of punctures on the elytra. P. oblongopunctatus has dorsal pits in the third interval of the elytra, the available identification keys, however, provide inconsistent information concerning the puncture in other intervals. During long-term studies at different study sites in Poland, the first author rarely but regularly discovered individuals with unusual dorsal puncture patterns, i.e., pits in the fifth and even in the seventh interval of the elytra. Since such rare patterns might be connected with special habitat characteristics, and thus have a potential as an indicator, the aim of the study was to test if they are connected with specific subpopulations (interaction groups, if they are related to the sex or size of the beetles, and if they are related to specific habitat conditions. Material and Methods We counted the pits on the elytra, determined the sex, and measured the length of the right elytron of individuals of P. oblongopunctatus collected at numerous study sites located within the borders of the Regional Directory of National Forests in Piła (Western Poland over the period 2014–2016. Results Altogether, 1,058 individuals of P. oblongopunctatus were subjected to statistical analysis. Almost 19% of the individuals had a dorsal puncture in the fifth interval of the elytra and about 0.7% had a dorsal puncture in the seventh interval of the elytra. In 2014 and 2015, significantly more females exhibited such unusual patterns of dorsal puncture than males. Even if not statistically significant, in 2016 also relatively more females showed such a pattern. Neither males nor females of the analysed individuals with usual puncture patterns showed a significant difference in the length of the right elytron from those with

The Histamine H1 Receptor Participates in the Increased Dorsal Telencephalic Neurogenesis in Embryos from Diabetic Rats

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Karina H. Solís

2017-12-01

Full Text Available Increased neuron telencephalic differentiation during deep cortical layer formation has been reported in embryos from diabetic mice. Transitory histaminergic neurons within the mesencephalon/rhombencephalon are responsible for fetal histamine synthesis during development, fibers from this system arrives to the frontal and parietal cortex at embryo day (E 15. Histamine is a neurogenic factor for cortical neural stem cells in vitro through H1 receptor (H1R which is highly expressed during corticogenesis in rats and mice. Furthermore, in utero administration of an H1R antagonist, chlorpheniramine, decreases the neuron markers microtubuline associated protein 2 (MAP2 and forkhead box protein 2. Interestingly, in the diabetic mouse model of diabetes induced with streptozotocin, an increase in fetal neurogenesis in terms of MAP2 expression in the telencephalon is reported at E11.5. Because of the reported effects on cortical neuron differentiation of maternal diabetes in one hand and of histamine in the other, here the participation of histamine and H1R on the increased dorsal telencephalic neurogenesis was explored. First, the increased neurogenesis in the dorsal telencephalon at E14 in diabetic rats was corroborated by immunohistochemistry and Western blot. Then, changes during corticogenesis in the level of histamine was analyzed by ELISA and in H1R expression by qRT-PCR and Western blot and, finally, we tested H1R participation in the increased dorsal telencephalic neurogenesis by the systemic administration of chlorpheniramine. Our results showed a significant increase of histamine at E14 and in the expression of the receptor at E12. The administration of chlorpheniramine to diabetic rats at E12 prevented the increased expression of βIII-tubulin and MAP2 mRNAs (neuron markers and partially reverted the increased level of MAP2 protein at E14, concluding that H1R have an important role in the increased neurogenesis within the dorsal telencephalon

The ventral stream offers more affordance and the dorsal stream more memory than believed

NARCIS (Netherlands)

Postma, Albert; van der Lubbe, Robert Henricus Johannes; Zuidhoek, Sander

2002-01-01

Opposed to Norman's proposal, processing of affordance is likely to occur not solely in the dorsal stream but also in the ventral stream. Moreover, the dorsal stream might do more than just serve an important role in motor actions. It supports egocentric location coding as well. As such, it would

RESULTS OF DIAGNOSTICAL BLOCK OF LONG DORSAL SACROILIAC LIGAMENT UNDER SONOGRAPHIC CONTROL IN PATIENTS WITH LOW BACK PAIN

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Yurkovskiy A. M.

2018-02-01

Full Text Available Purpose: to improve effectiveness of diagnostic block of long dorsal sacroiliac ligament performed under sonographic control in patients with low back pain caused by pathology of this ligament. Material and methods: the research included 35 patients (average age 46,2±12,5 years with symptoms of low back pain caused by pathology of long dorsal sacroiliac ligament. Diagnostical block of the given ligament was made under ultrasound control. Results: significant pain syndrome reduction was observed in all patients with ligamentopathy of long dorsal sacroiliac ligament. Conclusion: compared to "blind" technique, long dorsal sacroiliac ligament block performed under sonographic control is a more efficient method of verification and treatment for low back pain syndrome in case of long dorsal sacroiliac ligament injury.

Age-related hearing loss: Aquaporin 4 gene expression changes in the mouse cochlea and auditory midbrain

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Christensen, Nathan; D'Souza, Mary; Zhu, Xiaoxia; Frisina, Robert D.

2009-01-01

Presbycusis – age-related hearing loss, is the number one communication disorder, and one of the top three chronic medical conditions of our aged population. Aquaporins, particularly aquaporin 4 (Aqp4), are membrane proteins with important roles in water and ion flux across cell membranes, including cells of the inner ear and pathways of the brain used for hearing. To more fully understand the biological bases of presbycusis, 39 CBA mice, a well-studied animal model of presbycusis, underwent non-invasive hearing testing as a function of sound frequency (auditory brainstem response – ABR thresholds, and distortion-product otoacoustic emission – DPOAE magnitudes), and were clustered into four groups based on age and hearing ability. Aqp4 gene expression, as determined by genechip microarray analysis and quantitative real-time PCR, was compared to the young adult control group in the three older groups: middle aged with good hearing, old age with mild presbycusis, and old age with severe presbycusis. Linear regression and ANOVA showed statistically significant changes in Aqp4 gene expression and ABR and DPOAE hearing status in the cochlea and auditory midbrain – inferior colliculus. Down-regulation in the cochlea was seen, and an initial down-, then up-regulation was discovered for the inferior colliculus Aqp4 expression. It is theorized that these changes in Aqp4 gene expression represent an age-related disruption of ion flux in the fluids of the cochlea that are responsible for ionic gradients underlying sound transduction in cochlear hair cells necessary for hearing. In regard to central auditory processing at the level of the auditory midbrain, aquaporin gene expression changes may affect neurotransmitter cycling involving supporting cells, thus impairing complex sound neural processing with age. PMID:19070604

Unilateral lesion of dorsal hippocampus in adult rats impairs contralateral long-term potentiation in vivo and spatial memory in the early postoperative phase.

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Li, Hongjie; Wu, Xiaoyan; Bai, Yanrui; Huang, Yan; He, Wenting; Dong, Zhifang

2012-05-01

It is well documented that bilateral hippocampal lesions or unilateral hippocampal lesion at birth causes impairment of contralateral LTP and long-term memory. However, effects of unilateral hippocampal lesion in adults on contralateral in vivo LTP and memory are not clear. We here examined the influence of unilateral electrolytic dorsal hippocampal lesion in adult rats on contralateral LTP in vivo and spatial memory during different postoperative phases. We found that acute unilateral hippocampal lesion had no effect on contralateral LTP. However, contralateral LTP was impaired at 1 week after lesion, and was restored to the control level at postoperative week 4. Similarly, spatial memory was also impaired at postoperative week 1, and was restored at postoperative week 4. In addition, the rats at postoperative week 1 showed stronger spatial exploratory behavior in a novel open-field environment. The sham operation had no effects on contralateral LTP, spatial memory and exploration at either postoperative week 1 or week 4. These results suggest that unilateral dorsal hippocampal lesion in adult rats causes transient contralateral LTP impairment and spatial memory deficit. Copyright © 2012 Elsevier B.V. All rights reserved.

Clinical and neuroradiological studies on internuclear ophthalmoplegia

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Ito, Michiko; Uchiyama, Shinichiro; Endo, Riuko; Aikawa, Takashi; Kobayashi, Itsuro; Takemiya, Toshiko; Maruyama, Shoichi (Tokyo Women' s Medical Coll. (Japan))

1989-06-01

In this study 14 cases of internuclear ophthalmoplegia (INO) were analysed. The correlation of clinical symptoms with localization of the responsible lesions was studied in these patients. The subjects included 9 patients with CVD, 2 with MS, 1 with Fisher's syndrome, 1 with cranial polyneuritis and one with unknown etiology. Nine patients with unilateral INO are all associated with brainstem infarction. The other 5 patients including 2 MS had bilateral INO. CT showed abnormal findings in brain stem in 7 out of 14 patients. As for MRI an abnormality was found in 5 out of the 8 patients examined. Two of the 7 patients without any abnormality on CT had abnormal signals on MRI. We divided INO into 3 groups based on the clinical symptoms: (1) anterior type in which convergence was involved concomitantly with adduction paralysis, (2) typical type in which dissociated nystagmus was more marked in the abducting eye, and convergence was preserved, (3) posterior type in which abduction is impaired without adduction disturbance. There were 5 cases of anterior type, 9 of typical type, and none of posterior type. On MRI two patients of anterior type had abnormalities in the dorsal midbrain, and one patient had an abnormality in the pons, and two patients of typical type had abnormalities in the upper or middle dorsal pons to the dorsal midbrain. CT failed to demontrate any responsible lesions in 2 patients in whom the responsible legions were clearly identified on MRI. (J.P.N.).

The function of the long dorsal sacroiliac ligament : its implications for understanding low back pain

NARCIS (Netherlands)

Pool-Goudzwaard, A.L.; Vleeming, A; Hammudoghlu, D; Stoeckart, R.; Snijders, C.; Mens, Jan M A

1996-01-01

STUDY DESIGN: In embalmed human bodies the tension of the long dorsal sacroiliac ligament was measured during incremental loading of anatomical structures that are biomechanically relevant. OBJECTIVES: To assess the function of the long dorsal sacroiliac ligament. SUMMARY OF BACKGROUND DATA: In many

Dorsal inlay buccal mucosal graft (Asopa) urethroplasty for anterior urethral stricture.

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Marshall, Stephen D; Raup, Valary T; Brandes, Steven B

2015-02-01

Asopa described the inlay of a graft into Snodgrass's longitudinal urethral plate incision using a ventral sagittal urethrotomy approach in 2001. He claimed that this technique was easier to perform and led to less tissue ischemia due to no need for mobilization of the urethra. This approach has subsequently been popularized among reconstructive urologists as the dorsal inlay urethroplasty or Asopa technique. Depending on the location of the stricture, either a subcoronal circumferential incision is made for penile strictures, or a midline perineal incision is made for bulbar strictures. Other approaches for penile urethral strictures include the non-circumferential penile incisional approach and a penoscrotal approach. We generally prefer the circumferential degloving approach for penile urethral strictures. The penis is de-gloved and the urethra is split ventrally to exposure the stricture. It is then deepened to include the full thickness of the dorsal urethra. The dorsal surface is made raw and grafts are fixed on the urethral surface. Quilting sutures are placed to further anchor the graft. A Foley catheter is placed and the urethra is retubularized in two layers with special attention to the staggering of suture lines. The skin incision is then closed in layers. We have found that it is best to perform an Asopa urethroplasty when the urethral plate is ≥1 cm in width. The key to when to use the dorsal inlay technique all depends on the width of the urethral plate once the urethrotomy is performed, stricture etiology, and stricture location (penile vs. bulb).

Osteology of the dorsal vertebrae of the giant titanosaurian sauropod dinosaur Dreadnoughtus schrani from the Late Cretaceous of Argentina

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Kristyn K. Voegele

2017-11-01

Full Text Available Many titanosaurian dinosaurs are known only from fragmentary remains, making comparisons between taxa difficult because they often lack overlapping skeletal elements. This problem is particularly pronounced for the exceptionally large-bodied members of this sauropod clade. Dreadnoughtus schrani is a well-preserved giant titanosaurian from the Upper Cretaceous (Campanian–Maastrichtian Cerro Fortaleza Formation of southern Patagonia, Argentina. Numerous skeletal elements are known for Dreadnoughtus, including seven nearly complete dorsal vertebrae and a partial dorsal neural arch that collectively represent most of the dorsal sequence. Here we build on our previous preliminary description of these skeletal elements by providing a detailed assessment of their serial positional assignments, as well as comparisons of the dorsal vertebrae of Dreadnoughtus with those of other exceptionally large-bodied titanosaurians. Although the dorsal elements of Dreadnoughtus probably belong to two individuals, they exhibit substantial morphological variation that suggests that there is minimal, if any, positional overlap among them. Dreadnoughtus therefore preserves the second-most complete dorsal vertebral series known for a giant titanosaurian that has been described in detail, behind only that of Futalognkosaurus. The dorsal sequence of Dreadnoughtus provides valuable insight into serial variation along the vertebral column of these enormous sauropods. Such variation includes the variable presence of divided spinodiapophyseal laminae and associated spinodiapophyseal fossae. Given that dorsal vertebrae are the only elements that overlap between known remains of most giant titanosaurian taxa, the dorsal series of Dreadnoughtus provides a means to directly compare the morphologies of these sauropods. The dorsal vertebrae of Dreadnoughtus and Futalognkosaurus have dorsoventrally narrow transverse processes, unlike the condition in Puertasaurus. Further

Asymmetric distribution of hypoxia-inducible factor α regulates dorsoventral axis establishment in the early sea urchin embryo.

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Chang, Wei-Lun; Chang, Yi-Cheng; Lin, Kuan-Ting; Li, Han-Ru; Pai, Chih-Yu; Chen, Jen-Hao; Su, Yi-Hsien

2017-08-15

Hypoxia signaling is an ancient pathway by which animals can respond to low oxygen. Malfunction of this pathway disturbs hypoxic acclimation and can result in various diseases, including cancers. The role of hypoxia signaling in early embryogenesis remains unclear. Here, we show that in the blastula of the sea urchin Strongylocentrotus purpuratus , hypoxia-inducible factor α (HIFα), the downstream transcription factor of the hypoxia pathway, is localized and transcriptionally active on the future dorsal side. This asymmetric distribution is attributable to its oxygen-sensing ability. Manipulations of the HIFα level entrained the dorsoventral axis, as the side with the higher level of HIFα tends to develop into the dorsal side. Gene expression analyses revealed that HIFα restricts the expression of nodal to the ventral side and activates several genes encoding transcription factors on the dorsal side. We also observed that intrinsic hypoxic signals in the early embryos formed a gradient, which was disrupted under hypoxic conditions. Our results reveal an unprecedented role of the hypoxia pathway in animal development. © 2017. Published by The Company of Biologists Ltd.

Demonstration of the dorsal pancreatic artery by CTA to facilitate superselective arterial infusion of stem cells into the pancreas

International Nuclear Information System (INIS)

Lin Yuning; Yang Xizhang; Chen Ziqian; Tan Jianming; Zhong Qun; Yang Li; Wu Zhixian

2012-01-01

Purpose: To investigate the diagnostic performance of 64-section CTA in the detection of dorsal pancreatic artery before interventional therapy for patients with diabetes. Materials and methods: The study was approved by the institutional ethics committee; written informed consent was obtained. Forty-two consecutive patients with diabetes received an experimental treatment of autologous bone marrow-derived stem cell transplantation by means of infusion into the dorsal pancreatic artery. All cases underwent abdominal CTA before angiography of pancreatic arteries in order to locate the origin and course of dorsal pancreatic artery. Angiography of coeliac artery, splenic artery, common hepatic artery and superior mesenteric artery were performed both in CTA and DSA. Superselective catheterization of dorsal pancreatic artery was carried out for the infusion of stem cell. Sensitivity, specificity and accuracy for the detection of dorsal pancreatic artery with CTA were calculated using DSA images as the reference standard. Results: Thirty-five and thirty-six dorsal pancreatic arteries were detected by CTA and DSA respectively. Dorsal pancreatic artery was not visualized in either CTA or DSA in 5 patients. The sensitivity, specificity and accuracy for CTA were 94.4%, 83.3% and 92.9%. Conclusion: 64-section CTA is accurate for the detection of dorsal pancreatic artery. It may be useful for the facilitation of superselective arterial infusion of stem cells to pancreas.

Motor deficits following dorsal corticospinal tract transection in rats: voluntary versus skilled locomotion readouts

Directory of Open Access Journals (Sweden)

Lara Bieler

2018-02-01

The functional relevance of the dorsal CST in locomotion of rats is not as prominent as compared to in humans and thus challenging the motor execution is mandatory to reliably investigate CST function. A detailed analysis of voluntary walking using the CatWalk XT is not adequate to detect deficits following dorsal CST lesion in rats.

Harmane inhibits serotonergic dorsal raphe neurons in the rat.

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Touiki, Khalid; Rat, Pascal; Molimard, Robert; Chait, Abderrahman; de Beaurepaire, Renaud

2005-11-01

Harmane and norharmane (two beta-carbolines) are tobacco components or products. The effects of harmane and norharmane on serotonergic raphe neurons remain unknown. Harmane and norharmane are inhibitors of the monoamine oxidases A (MAO-A) and B (MAO-B), respectively. To study the effects of harmane, norharmane, befloxatone (MAOI-A), and selegiline (MAOI-B) on the firing of serotonergic neurons. To compare the effects of these compounds to those of nicotine (whose inhibitory action on serotonergic neurons has been previously described). The effects of cotinine, a metabolite of nicotine known to interact with serotonergic systems, are also tested. In vivo electrophysiological recordings of serotonergic dorsal raphe neurons in the anaesthetized rat. Nicotine, harmane, and befloxatone inhibited serotonergic dorsal raphe neurons. The other compounds had no effects. The inhibitory effect of harmane (rapid and long-lasting inhibition) differed from that of nicotine (short and rapidly reversed inhibition) and from that of befloxatone (slow, progressive, and long-lasting inhibition). The inhibitory effects of harmane and befloxatone were reversed by the 5-HT1A antagonist WAY 100 635. Pretreatment of animals with p-chlorophenylalanine abolished the inhibitory effect of befloxatone, but not that of harmane. Nicotine, harmane, and befloxatone inhibit the activity of raphe serotonergic neurons. Therefore, at least two tobacco compounds, nicotine and harmane, inhibit the activity of serotonergic neurons. The mechanism by which harmane inhibits serotonergic dorsal raphe neurons is likely unrelated to a MAO-A inhibitory effect.

Astrocyte Hypertrophy and Microglia Activation in the Rat Auditory Midbrain Is Induced by Electrical Intracochlear Stimulation.

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Rosskothen-Kuhl, Nicole; Hildebrandt, Heika; Birkenhäger, Ralf; Illing, Robert-Benjamin

2018-01-01

Neuron-glia interactions contribute to tissue homeostasis and functional plasticity in the mammalian brain, but it remains unclear how this is achieved. The potential of central auditory brain tissue for stimulation-dependent cellular remodeling was studied in hearing-experienced and neonatally deafened rats. At adulthood, both groups received an intracochlear electrode into the left cochlea and were continuously stimulated for 1 or 7 days after waking up from anesthesia. Normal hearing and deafness were assessed by auditory brainstem responses (ABRs). The effectiveness of stimulation was verified by electrically evoked ABRs as well as immunocytochemistry and in situ hybridization for the immediate early gene product Fos on sections through the auditory midbrain containing the inferior colliculus (IC). Whereas hearing-experienced animals showed a tonotopically restricted Fos response in the IC contralateral to electrical intracochlear stimulation, Fos-positive neurons were found almost throughout the contralateral IC in deaf animals. In deaf rats, the Fos response was accompanied by a massive increase of GFAP indicating astrocytic hypertrophy, and a local activation of microglial cells identified by IBA1. These glia responses led to a noticeable increase of neuron-glia approximations. Moreover, staining for the GABA synthetizing enzymes GAD65 and GAD67 rose significantly in neuronal cell bodies and presynaptic boutons in the contralateral IC of deaf rats. Activation of neurons and glial cells and tissue re-composition were in no case accompanied by cell death as would have been apparent by a Tunel reaction. These findings suggest that growth and activity of glial cells is crucial for the local adjustment of neuronal inhibition to neuronal excitation.

Dorsal hand coverage with free serratus fascia flap

DEFF Research Database (Denmark)

Fotopoulos, Peter; Holmer, Per; Leicht, Pernille

2003-01-01

in the flap, leaving the long thoracic nerve intact on the serratus muscle. Coverage of the flap with split-thickness skin graft is done immediately. The free serratus fascia flap is an ideal flap for dorsal hand coverage when the extensor tendons are exposed, especially because of low donor-site morbidity....

Avaliação da hiperalgesia e alterações histológicas do gânglio da raiz dorsal induzidas pelo núcleo pulposo Evaluation of hyperalgesia and histological changes of dorsal root ganglion induced by nucleus pulposus

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André Luiz de Souza Grava

2010-01-01

Full Text Available OBJETIVO: Avaliar a hiperalgesia e as alterações histológicas induzidas pelo contato do gânglio da raiz dorsal com o núcleo pulposo. MÉTODOS: Foram utilizados 20 ratos Wistar, divididos em dois grupos experimentais. Em um dos grupos um fragmento do NP autólogo retirado da região sacrococcígea foi colocado sobre os gânglios da raiz dorsal de L5, e no outro grupo (controle um fragmento de tecido adiposo foi colocado sobre o gânglio da raiz dorsal de L5. A hiperalgesia mecânica e térmica foi avaliada no terceiro dia, na primeira, terceira, quinta e sétima semanas de pós-operatório. O gânglio da raiz dorsal de L5 foi retirado na primeira, terceira, quinta e sétima semanas de pós-operatório para estudo histológico por meio da coloração com HE e estudo histoquímico (marcação específica para iNOS. RESULTADOS: Foi observada hiperalgesia térmica e mecânica de maior intensidade no grupo de animais em que o NP foi colocado em contato com o GRD, e nesse grupo o estudo histológico evidenciou alterações dos tecidos do gânglio da raiz dorsal, caracterizadas por processo inflamatório e degeneração axonal. As alterações histopatológicas dos tecidos do gânglio da raiz dorsal apresentaram intensidade crescente com o aumento do período de observação, apresentando correlação com a manutenção da hiperalgesia observada na avaliação comportamental. A imunohistoquímica com marcação específica para iNOS demonstrou, no grupo de animais em que o núcleo pulposo foi colocado em contato com o gânglio da raiz dorsal, aumento da expressão dessa enzima nos núcleos das células inflamatórias (células da glia ao redor dos neurônios. CONCLUSÃO: O contato do núcleo pulposo com o gânglio da raiz dorsal de L5 induziu a hiperalgesia mecânica e térmica e provocou alterações histológicas dos componentes do gânglio da raiz dorsal. As alterações foram caracterizadas por processo inflamatório e degenerativo das

Detailed Surgical Anatomy of Prostate: Relationship between Urethra and Dorsal Vein Complex with Apex.

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Tunc, Lutfi; Akin, Yigit; Gumustas, Huseyin; Ak, Esat; Peker, Tuncay; Veneziano, Domenico; Guneri, Cagri

2016-01-01

To describe our surgical technique for dissecting the apex of prostate during robotic-assisted laparoscopic radical prostatectomy (RALP) and detailed surgical anatomy of prostate including relationship between urethra and dorsal vein complex with apex. In retrospective view of prospective collected data, 73 patients underwent RALP between December 2012 and September 2014. Surgical anatomy of prostate was revealed in all procedures. Quality of life (QoL) scores were assessed before, immediately after catheter removal, and 1 month after surgery. We divided urinary continence into 3 groups, as very early continence; continence at time of urethral catheter removal, early continent; and continence 1 month after surgery. The rest of the patients were accepted as continence. The mean follow-up was 10.2 ± 5.4 months and mean age was 61.5 ± 6.6. Maximum protection of urethra could be provided in all. Mean catheter removal was 8.9 ± 1.7 days, and all patients were continent at the time of catheter removal. QoL scores before RALP could be protected after surgery (p = 0.2). Neither conversion to open/conventional laparoscopic surgery nor complications related with bladder neck were detected. Our surgical technique can be a strong candidate for being a surgical technique for preserving urethra and very early continence could be provided after surgery. © 2016 S. Karger AG, Basel.

Neuroimaging investigations of dorsal stream processing and effects of stimulus synchrony in schizophrenia.

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Sanfratello, Lori; Aine, Cheryl; Stephen, Julia

2018-05-25

Impairments in auditory and visual processing are common in schizophrenia (SP). In the unisensory realm visual deficits are primarily noted for the dorsal visual stream. In addition, insensitivity to timing offsets between stimuli are widely reported for SP. The aim of the present study was to test at the physiological level differences in dorsal/ventral stream visual processing and timing sensitivity between SP and healthy controls (HC) using MEG and a simple auditory/visual task utilizing a variety of multisensory conditions. The paradigm included all combinations of synchronous/asynchronous and central/peripheral stimuli, yielding 4 task conditions. Both HC and SP groups showed activation in parietal areas (dorsal visual stream) during all multisensory conditions, with parietal areas showing decreased activation for SP relative to HC, and a significantly delayed peak of activation for SP in intraparietal sulcus (IPS). We also observed a differential effect of stimulus synchrony on HC and SP parietal response. Furthermore, a (negative) correlation was found between SP positive symptoms and activity in IPS. Taken together, our results provide evidence of impairment of the dorsal visual stream in SP during a multisensory task, along with an altered response to timing offsets between presented multisensory stimuli. Copyright © 2018 Elsevier B.V. All rights reserved.

Opposing dorsal/ventral stream dynamics during figure-ground segregation

NARCIS (Netherlands)

Wokke, M.E.; Scholte, H.S.; Lamme, V.A.F.

2014-01-01

The visual system has been commonly subdivided into two segregated visual processing streams: The dorsal pathway processes mainly spatial information, and the ventral pathway specializes in object perception. Recent findings, however, indicate that different forms of interaction (cross-talk) exist

A study of dorsal vein pattern for biometric security

African Journals Online (AJOL)

Nafiisah

ensure more reliable security, many biometric verification techniques have been developed .... 3.0 HA D DORSAL VEI PATTER AS A BIOMETRIC ... image for the back of the hand, and converted by a computer into a digital image that can be.

Functional Connectivity of the Dorsal Attention Network Predicts Selective Attention in 4-7 year-old Girls.

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Rohr, Christiane S; Vinette, Sarah A; Parsons, Kari A L; Cho, Ivy Y K; Dimond, Dennis; Benischek, Alina; Lebel, Catherine; Dewey, Deborah; Bray, Signe

2017-09-01

Early childhood is a period of profound neural development and remodeling during which attention skills undergo rapid maturation. Attention networks have been extensively studied in the adult brain, yet relatively little is known about changes in early childhood, and their relation to cognitive development. We investigated the association between age and functional connectivity (FC) within the dorsal attention network (DAN) and the association between FC and attention skills in early childhood. Functional magnetic resonance imaging data was collected during passive viewing in 44 typically developing female children between 4 and 7 years whose sustained, selective, and executive attention skills were assessed. FC of the intraparietal sulcus (IPS) and the frontal eye fields (FEF) was computed across the entire brain and regressed against age. Age was positively associated with FC between core nodes of the DAN, the IPS and the FEF, and negatively associated with FC between the DAN and regions of the default-mode network. Further, controlling for age, FC between the IPS and FEF was significantly associated with selective attention. These findings add to our understanding of early childhood development of attention networks and suggest that greater FC within the DAN is associated with better selective attention skills. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Characterisation of rebound depolarisation in mice deep dorsal horn neurons in vitro.

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Rivera-Arconada, Ivan; Lopez-Garcia, Jose A

2015-09-01

Spinal dorsal horn neurons constitute the first relay for pain processing and participate in the processing of other sensory, motor and autonomic information. At the cellular level, intrinsic excitability is a factor contributing to network function. In turn, excitability is set by the array of ionic conductance expressed by neurons. Here, we set out to characterise rebound depolarisation following hyperpolarisation, a feature frequently described in dorsal horn neurons but never addressed in depth. To this end, an in vitro preparation of the spinal cord from mice pups was used combined with whole-cell recordings in current and voltage clamp modes. Results show the expression of H- and/or T-type currents in a significant proportion of dorsal horn neurons. The expression of these currents determines the presence of rebound behaviour at the end of hyperpolarising pulses. T-type calcium currents were associated to high-amplitude rebounds usually involving high-frequency action potential firing. H-currents were associated to low-amplitude rebounds less prone to elicit firing or firing at lower frequencies. For a large proportion of neurons expressing both currents, the H-current constitutes a mechanism to ensure a faster response after hyperpolarisations, adjusting the latency of the rebound firing. We conclude that rebound depolarisation and firing are intrinsic factors to many dorsal horn neurons that may constitute a mechanism to integrate somatosensory information in the spinal cord, allowing for a rapid switch from inhibited-to-excited states.

Hypocretin-1 levels in the cerebrospinal fluid of patients with Percheron artery infarction with or without midbrain involvement: A case series.

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Suzuki, Keisuke; Miyamoto, Tomoyuki; Miyamoto, Masayuki; Maeda, Hiroto; Nokura, Kazuya; Tohyama, Jun; Hirata, Koichi; Shimizu, Tetsuo; Kanbayashi, Takashi

2016-07-01

Bilateral paramedian thalamic infarctions (BPTIs) due to artery of Percheron occlusion are known to cause hypersomnia. However, the role of hypocretin-1, a wake-promoting peptide that is located at the lateral hypothalamus, in hypersomnia in these patients remains unclear. To clarify the role of hypocretin-1 in hypersomnia in patients with BPTIs, hypocretin-1 levels in the cerebrospinal fluid (CSF) were measured in 6 patients with BPTIs: 2 with rostral midbrain involvement (BPT+RMI) and 4 without midbrain involvement (BPT-MI). CSF hypocretin-1 levels were decreased in 2 patients with BPT+RMI and were within normal ranges in 4 patients with BPT-MI. Hypersomnia was noted in all the patients. In one BPT+RMI patient, hypersomnia was improved within 2 weeks and decreased CSF hypocretin-1 levels were reversed (acute phase (on day 9), 109.2 pg/mL; chronic phase (at 3 months), 323 pg/mL), whereas another BPT+RMI patient who displayed coma in the acute phase had decreased CSF orexin levels (107 pg/mL) at day 49 and exhibited severe disability. Hypocretin deficiency was not involved in hypersomnia observed in BPT-MI patients; however, CSF hypocretin-1 levels were reduced in BPT+RMI patients. Reduced CSF hypocretin-1 levels in the chronic phase may possibly predict a poor clinical outcome in patients with Percheron artery infarction.

Isthmin is a novel secreted protein expressed as part of the Fgf-8 synexpression group in the Xenopus midbrain-hindbrain organizer.

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Pera, Edgar M; Kim, James I; Martinez, Sarah L; Brechner, Mariel; Li, Su Yu; Wessely, Oliver; De Robertis, E M

2002-08-01

Patterning of the central nervous system is regulated by a signaling center located at the midbrain-hindbrain boundary (MHB), or isthmus organizer. Fibroblast growth factors secreted from the MHB are required and sufficient to direct the ordered growth and regionalization of the midbrain and anterior hindbrain. In an unbiased secretion cloning screen of Xenopus gastrula embryos we identified a novel gene, which we designated as Isthmin (xIsm) due to its prominent expression at the MHB. xIsm encodes a secreted protein of 449 amino acids containing one copy of the thrombospondin type 1 repeat (TSR). We also found orthologous Isthmin genes in human (hIsm) and mouse (mIsm), as well as a gene encoding an Isthmin-like human unknown protein (hIsm-l). The conservation of a unique carboxy-terminal region between hIsm and hIsm-l suggests that Isthmin is the founding member of a new family of secreted proteins. xIsm was strongly expressed maternally in the Xenopus egg and showed zygotic expression in the ventral blastopore lip, notochord, and MHB. Additional expression domains were detected in neural crest, ear vesicle, and developing blood islands. Interestingly, xIsm was co-expressed with Fibroblast growth factor-8 (xFgf-8) at multiple sites including the MHB, indicating that these two genes are part of a synexpression group which also includes sprouty and sef homologs.

Dietary fat level affecting histochemical radiosensitivity in dorsal aorta in rats

International Nuclear Information System (INIS)

Yousri, R.M.; Roushdy, H.M.; EL-Malkh, N.M.; Ashry, M.A.; Soliman, S.M.

1988-01-01

The present work has been conducted to investigate the effect of dietary fat status and/or cumulative whole body gamma radiation exposures up to 15 Gy the histochemical pattern of the dorsal aortas of male albino rats. Experimental animals were fed on either fat-rich or fat-free diet and the observations compared with those fed normal fat diet. The histochemical investigations has been confined to the concentration levels of mucopolysaccharide substance and total lipids. The dorsal aorta normal fat group showed higher content of PAS-positive material in the first two layers of the aorta wall in comparison with decreased amount of collagen fibers was shown in fat-rich group

Heterotaxy syndrome with associated agenesis of dorsal pancreas and polysplenia: A case report

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Syed Althaf Ali1

2015-01-01

Full Text Available Heterotaxy syndrome is a rare embryological disorder comprising of polysplenia, partial agenesis of dorsal pancreas, malrotation of gut, cardiac and vascular anomalies resulting from failure of development of the usual left–right asymmetry of organs. We report a rare case of heterotaxy syndrome with polysplenia, partial agenesis of dorsal pancreas and malrotation of gut in a 28 year female presenting with subacute intestinal obstruction along with imaging illustrations, brief discussion and thorough review of literature.

Ventral and Dorsal Striatum Networks in Obesity: Link to Food Craving and Weight Gain.

Science.gov (United States)

Contreras-Rodríguez, Oren; Martín-Pérez, Cristina; Vilar-López, Raquel; Verdejo-Garcia, Antonio

2017-05-01

The food addiction model proposes that obesity overlaps with addiction in terms of neurobiological alterations in the striatum and related clinical manifestations (i.e., craving and persistence of unhealthy habits). Therefore, we aimed to examine the functional connectivity of the striatum in excess-weight versus normal-weight subjects and to determine the extent of the association between striatum connectivity and individual differences in food craving and changes in body mass index (BMI). Forty-two excess-weight participants (BMI > 25) and 39 normal-weight participants enrolled in the study. Functional connectivity in the ventral and dorsal striatum was indicated by seed-based analyses on resting-state data. Food craving was indicated with subjective ratings of visual cues of high-calorie food. Changes in BMI between baseline and 12 weeks follow-up were assessed in 28 excess-weight participants. Measures of connectivity in the ventral striatum and dorsal striatum were compared between groups and correlated with craving and BMI change. Participants with excess weight displayed increased functional connectivity between the ventral striatum and the medial prefrontal and parietal cortices and between the dorsal striatum and the somatosensory cortex. Dorsal striatum connectivity correlated with food craving and predicted BMI gains. Obesity is linked to alterations in the functional connectivity of dorsal striatal networks relevant to food craving and weight gain. These neural alterations are associated with habit learning and thus compatible with the food addiction model of obesity. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Upregulation of adrenomedullin in the spinal cord and dorsal root ganglia in the early phase of CFA-induced inflammation in rats.

Science.gov (United States)

Hong, Yanguo; Liu, Yushan; Chabot, Jean-Guy; Fournier, Alain; Quirion, Rémi

2009-11-01

Adrenomedullin (AM), a member of calcitonin gene-related peptide (CGRP) family, has been demonstrated to be a pronociceptive mediator [28]. This study was undertaken to investigate the role of AM in a model of complete Freund's adjuvant (CFA)-induced inflammatory pain. Injection of CFA, but not of saline, in the unilateral hindpaw produced an increase in the expression of AM-like immunoreactivity (AM-IR) in laminae I-II of the spinal cord as well as in small- and medium-sized dorsal root ganglion (DRG) neurons at 48 h. The content of AM in DRG on the side ipsilateral to CFA injection started to increase at 4 h and remained at high levels at 24 and 48 h. The selective antagonist of AM receptors, AM(22-52), administered intrathecally (i.t.) 24 h after CFA injection inhibited inflammation-associated hyperalgesia in a dose-dependent manner (2, 5 and 10 nmol). Impressively, this anti-hyperalgesic effect lasted for at least 24 h. I.t. administration of AM(22-52) (10 nmol) also reversed CFA-induced increase in AM-IR in the spinal dorsal horn and DRG. Furthermore, blockade of AM receptors abolished CFA-induced changes in the expression and content of CGRP-like immunoreactivity in these regions. Taken together, our results suggest that the upregulation of AM in DRG neurons contributes to the development of inflammatory pain, and this effect is mediated, at least in part, by enhancing the expression and release of CGRP. Blocking AM receptor downstream signaling effects using antagonists has the potential of relieving pain following the induction of inflammation.

Automatic phoneme category selectivity in the dorsal auditory stream.

Science.gov (United States)

Chevillet, Mark A; Jiang, Xiong; Rauschecker, Josef P; Riesenhuber, Maximilian

2013-03-20

Debates about motor theories of speech perception have recently been reignited by a burst of reports implicating premotor cortex (PMC) in speech perception. Often, however, these debates conflate perceptual and decision processes. Evidence that PMC activity correlates with task difficulty and subject performance suggests that PMC might be recruited, in certain cases, to facilitate category judgments about speech sounds (rather than speech perception, which involves decoding of sounds). However, it remains unclear whether PMC does, indeed, exhibit neural selectivity that is relevant for speech decisions. Further, it is unknown whether PMC activity in such cases reflects input via the dorsal or ventral auditory pathway, and whether PMC processing of speech is automatic or task-dependent. In a novel modified categorization paradigm, we presented human subjects with paired speech sounds from a phonetic continuum but diverted their attention from phoneme category using a challenging dichotic listening task. Using fMRI rapid adaptation to probe neural selectivity, we observed acoustic-phonetic selectivity in left anterior and left posterior auditory cortical regions. Conversely, we observed phoneme-category selectivity in left PMC that correlated with explicit phoneme-categorization performance measured after scanning, suggesting that PMC recruitment can account for performance on phoneme-categorization tasks. Structural equation modeling revealed connectivity from posterior, but not anterior, auditory cortex to PMC, suggesting a dorsal route for auditory input to PMC. Our results provide evidence for an account of speech processing in which the dorsal stream mediates automatic sensorimotor integration of speech and may be recruited to support speech decision tasks.

Redundant roles of Sox17 and Sox18 in early cardiovascular development of mouse embryos

International Nuclear Information System (INIS)

Sakamoto, Youhei; Hara, Kenshiro; Kanai-Azuma, Masami; Matsui, Toshiyasu; Miura, Yutaroh; Tsunekawa, Naoki; Kurohmaru, Masamichi; Saijoh, Yukio; Koopman, Peter; Kanai, Yoshiakira

2007-01-01

Sox7, -17 and -18 constitute the Sox subgroup F (SoxF) of HMG box transcription factor genes, which all are co-expressed in developing vascular endothelial cells in mice. Here we characterized cardiovascular phenotypes of Sox17/Sox18-double and Sox17-single null embryos during early-somite stages. Whole-mount PECAM staining demonstrated the aberrant heart looping, enlarged cardinal vein and mild defects in anterior dorsal aorta formation in Sox17 single-null embryos. The Sox17/Sox18 double-null embryos showed more severe defects in formation of anterior dorsal aorta and head/cervical microvasculature, and in some cases, aberrant differentiation of endocardial cells and defective fusion of the endocardial tube. However, the posterior dorsal aorta and allantoic microvasculature was properly formed in all of the Sox17/Sox18 double-null embryos. The anomalies in both anterior dorsal aorta and head/cervical vasculature corresponded with the weak Sox7 expression sites. This suggests the region-specific redundant activities of three SoxF members along the anteroposterior axis of embryonic vascular network

An amphioxus Msx gene expressed predominantly in the dorsal neural tube.

Science.gov (United States)

Sharman, A C; Shimeld, S M; Holland, P W

1999-04-01

Genomic and cDNA clones of an Msx class homeobox gene were isolated from amphioxus (Branchiostoma floridae). The gene, AmphiMsx, is expressed in the neural plate from late gastrulation; in later embryos it is expressed in dorsal cells of the neural tube, excluding anterior and posterior regions, in an irregular reiterated pattern. There is transient expression in dorsal cells within somites, reminiscent of migrating neural crest cells of vertebrates. In larvae, mRNA is detected in two patches of anterior ectoderm proposed to be placodes. Evolutionary analyses show there is little phylogenetic information in Msx protein sequences; however, it is likely that duplication of Msx genes occurred in the vertebrate lineage.

Dickkopf 3 Promotes the Differentiation of a Rostrolateral Midbrain Dopaminergic Neuronal Subset In Vivo and from Pluripotent Stem Cells In Vitro in the Mouse.

Science.gov (United States)

Fukusumi, Yoshiyasu; Meier, Florian; Götz, Sebastian; Matheus, Friederike; Irmler, Martin; Beckervordersandforth, Ruth; Faus-Kessler, Theresa; Minina, Eleonora; Rauser, Benedict; Zhang, Jingzhong; Arenas, Ernest; Andersson, Elisabet; Niehrs, Christof; Beckers, Johannes; Simeone, Antonio; Wurst, Wolfgang; Prakash, Nilima

2015-09-30

Wingless-related MMTV integration site 1 (WNT1)/β-catenin signaling plays a crucial role in the generation of mesodiencephalic dopaminergic (mdDA) neurons, including the substantia nigra pars compacta (SNc) subpopulation that preferentially degenerates in Parkinson's disease (PD). However, the precise functions of WNT1/β-catenin signaling in this context remain unknown. Stem cell-based regenerative (transplantation) therapies for PD have not been implemented widely in the clinical context, among other reasons because of the heterogeneity and incomplete differentiation of the transplanted cells. This might result in tumor formation and poor integration of the transplanted cells into the dopaminergic circuitry of the brain. Dickkopf 3 (DKK3) is a secreted glycoprotein implicated in the modulation of WNT/β-catenin signaling. Using mutant mice, primary ventral midbrain cells, and pluripotent stem cells, we show that DKK3 is necessary and sufficient for the correct differentiation of a rostrolateral mdDA neuron subset. Dkk3 transcription in the murine ventral midbrain coincides with the onset of mdDA neurogenesis and is required for the activation and/or maintenance of LMX1A (LIM homeobox transcription factor 1α) and PITX3 (paired-like homeodomain transcription factor 3) expression in the corresponding mdDA precursor subset, without affecting the proliferation or specification of their progenitors. Notably, the treatment of differentiating pluripotent stem cells with recombinant DKK3 and WNT1 proteins also increases the proportion of mdDA neurons with molecular SNc DA cell characteristics in these cultures. The specific effects of DKK3 on the differentiation of rostrolateral mdDA neurons in the murine ventral midbrain, together with its known prosurvival and anti-tumorigenic properties, make it a good candidate for the improvement of regenerative and neuroprotective strategies in the treatment of PD. Significance statement: We show here that Dickkopf 3 (DKK3), a

Morphology and histology of dorsal spines of the xenacanthid shark Orthacanthus platypternus from the Lower Permian of Texas, USA: palaeobiological and palaeoenvironmental implications

Directory of Open Access Journals (Sweden)

Kimberly G. Beck

2016-02-01

Full Text Available Detailed studies on Carboniferous species of the xenacanth Orthacanthus have shown that the xenacanth dorsal fin spine can be used for skeletochronological analyses and provides valuable information about development, growth and environmental life conditions of those extinct sharks. We report here for the first time the histology and skeletochronology of Permian specimens, dorsal spines of Orthacanthus platypternus from the Craddock Bone Bed (lower Clear Fork Formation; Early Permian, Leonardian age of northern Baylor County (north-central Texas, USA. Twelve dorsal spines of O. platypternus preserve a highly vascularized wall mainly composed of centrifugally growing dentine in a succession of dentine layers, probably deposited with an annual periodicity. As expected, spines of individuals with 1–2 dentine layers, presumably juveniles, present the smallest sizes. However, spines of individuals showing at least 3–4 dentine layers and interpreted to be subadults/young adults, are distributed in two spine-size clusters corresponding to females (probably the largest spines and males, in agreement with the hypothesis of sexual size dimorphism proposed in a previous biometric analysis. Our comparative study of O. platypternus and the Stephanian species O. meridionalis further suggests that spine denticulation can be useful for distinguishing between species of Orthacanthus and sexually dimorphic forms (juvenile to adults in each species. Total body length estimations of O. platypternus from the Craddock Bone Bed point to relatively large juveniles and small subadults/young adults (less than 2 m in total length, living as opportunistic predators in the pond-channel coastal plain environments represented by the bone bed deposits. The com-parative analyses of the ontogenetic stages of the recorded specimens of O. platypternus and their distribution along different facies and localities indicate that this species was euryhaline, diadromous with a

Modality-Based Organization of Ascending Somatosensory Axons in the Direct Dorsal Column Pathway

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Niu, Jingwen; Ding, Long; Li, Jian J.; Kim, Hyukmin; Liu, Jiakun; Li, Haipeng; Moberly, Andrew; Badea, Tudor C.; Duncan, Ian D.; Son, Young-Jin; Scherer, Steven S.

2013-01-01

The long-standing doctrine regarding the functional organization of the direct dorsal column (DDC) pathway is the “somatotopic map” model, which suggests that somatosensory afferents are primarily organized by receptive field instead of modality. Using modality-specific genetic tracing, here we show that ascending mechanosensory and proprioceptive axons, two main types of the DDC afferents, are largely segregated into a medial–lateral pattern in the mouse dorsal column and medulla. In addition, we found that this modality-based organization is likely to be conserved in other mammalian species, including human. Furthermore, we identified key morphological differences between these two types of afferents, which explains how modality segregation is formed and why a rough “somatotopic map” was previously detected. Collectively, our results establish a new functional organization model for the mammalian direct dorsal column pathway and provide insight into how somatotopic and modality-based organization coexist in the central somatosensory pathway. PMID:24198362

Electroacupuncture reduces the evoked responses of the spinal dorsal horn neurons in ankle-sprained rats

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Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon

2011-01-01

Acupuncture is shown to be effective in producing analgesia in ankle sprain pain in humans and animals. To examine the underlying mechanisms of the acupuncture-induced analgesia, the effects of electroacupuncture (EA) on weight-bearing forces (WBR) of the affected foot and dorsal horn neuron activities were examined in a rat model of ankle sprain. Ankle sprain was induced manually by overextending ligaments of the left ankle in the rat. Dorsal horn neuron responses to ankle movements or compression were recorded from the lumbar spinal cord using an in vivo extracellular single unit recording setup 1 day after ankle sprain. EA was applied to the SI-6 acupoint on the right forelimb (contralateral to the sprained ankle) by trains of electrical pulses (10 Hz, 1-ms pulse width, 2-mA intensity) for 30 min. After EA, WBR of the sprained foot significantly recovered and dorsal horn neuron activities were significantly suppressed in ankle-sprained rats. However, EA produced no effect in normal rats. The inhibitory effect of EA on hyperactivities of dorsal horn neurons of ankle-sprained rats was blocked by the α-adrenoceptor antagonist phentolamine (5 mg/kg ip) but not by the opioid receptor antagonist naltrexone (10 mg/kg ip). These data suggest that EA-induced analgesia in ankle sprain pain is mediated mainly by suppressing dorsal horn neuron activities through α-adrenergic descending inhibitory systems at the spinal level. PMID:21389301

Spiny Prey, Fortunate Prey. Dorsal Spines Are an Asset in Intraguild Interactions among Lady Beetles

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Louis Hautier

2017-11-01

Full Text Available The Multicolored Asian Ladybird, Harmonia axyridis, is an extremely successful invasive species. Here we suggest that, in addition to many other traits, the dorsal spines of its larvae contribute to their success, as suggested by behavioral observations of agonistic interactions between H. axyridis and European coccinellids. In coccinellids, the role of dorsal spines in these interactions has been poorly studied and they could be a physical protection against intraguild predators. Dorsal spines of second instar H. axyridis larvae were removed with micro-scissors, which resulted in spineless larvae after molting (spineless group. These larvae were then exposed to starved Coccinella septempunctata larvae. Two control categories were also submitted to interactions: H. axyridis larvae with all their spines (control group and with their spines, but injured by pin stings (injured group. Spine removal at the second instar did not hamper H. axyridis development. The bite rate by C. septempunctata was significantly higher on the spineless H. axyridis and more dorsally located compared to the control and injured groups, while no bite rate difference was observed between the injured and the control group. Our results suggest that in addition to behavioral and chemical defenses, the dorsal spines play a significant protective role against bites. Therefore, spines in ladybirds could be considered as a morphological defense against intraguild predation. In H. axyridis, these defenses might contribute to its success in food resources already exploited by other guild members and thus further facilitate the invasion of new areas.

LPXRFa peptide system in the European sea bass: A molecular and immunohistochemical approach.

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Paullada-Salmerón, José A; Cowan, Mairi; Aliaga-Guerrero, María; Gómez, Ana; Zanuy, Silvia; Mañanos, Evaristo; Muñoz-Cueto, José A

2016-01-01

Gonadotropin-inhibitory hormone (GnIH) is a neuropeptide that suppresses reproduction in birds and mammals by inhibiting GnRH and gonadotropin secretion. GnIH orthologs with a C-terminal LPXRFamide (LPXRFa) motif have been identified in teleost fish. Although recent work also suggests its role in fish reproduction, studies are scarce and controversial, and have mainly focused on cyprinids. In this work we cloned a full-length cDNA encoding an LPXRFa precursor in the European sea bass, Dicentrarchus labrax. In contrast to other teleosts, the sea bass LPXRFa precursor contains only two putative RFamide peptides, termed sbLPXRFa1 and sbLPXRFa2. sblpxrfa transcripts were expressed predominantly in the olfactory bulbs/telencephalon, diencephalon, midbrain tegmentum, retina, and gonads. We also developed a specific antiserum against sbLPXRFa2, which revealed sbLPXRFa-immunoreactive (ir) perikarya in the olfactory bulbs-terminal nerve, ventral telencephalon, caudal preoptic area, dorsal mesencephalic tegmentum, and rostral rhombencephalon. These sbLPXRFa-ir cells profusely innervated the preoptic area, hypothalamus, optic tectum, semicircular torus, and caudal midbrain tegmentum, but conspicuous projections also reached the olfactory bulbs, ventral/dorsal telencephalon, habenula, ventral thalamus, pretectum, rostral midbrain tegmentum, posterior tuberculum, reticular formation, and viscerosensory lobe. The retina, pineal, vascular sac, and pituitary were also targets of sbLPXRFa-ir cells. In the pituitary, this innervation was observed close to follicle-stimulating hormone (FSH), luteinizing hormone (LH) and growth hormone (GH) cells. Tract-tracing retrograde labeling suggests that telencephalic and preoptic sbLPXRFa cells might represent the source of pituitary innervation. The immunohistochemical distribution of sbLPXRFa cells and fibers suggest that LPXRFa peptides might be involved in some functions as well as reproduction, such as feeding, growth, and behavior. �

Excessive D1 Dopamine Receptor Activation in the Dorsal Striatum Promotes Autistic-Like Behaviors.

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Lee, Yunjin; Kim, Hannah; Kim, Ji-Eun; Park, Jin-Young; Choi, Juli; Lee, Jung-Eun; Lee, Eun-Hwa; Han, Pyung-Lim

2018-07-01

The dopamine system has been characterized in motor function, goal-directed behaviors, and rewards. Recent studies recognize various dopamine system genes as being associated with autism spectrum disorder (ASD). However, how dopamine system dysfunction induces ASD pathophysiology remains unknown. In the present study, we demonstrated that mice with increased dopamine functions in the dorsal striatum via the suppression of dopamine transporter expression in substantia nigra neurons or the optogenetic stimulation of the nigro-striatal circuitry exhibited sociability deficits and repetitive behaviors relevant to ASD pathology in animal models, while these behavioral changes were blocked by a D1 receptor antagonist. Pharmacological activation of D1 dopamine receptors in normal mice or the genetic knockout (KO) of D2 dopamine receptors also produced typical autistic-like behaviors. Moreover, the siRNA-mediated inhibition of D2 dopamine receptors in the dorsal striatum was sufficient to replicate autistic-like phenotypes in D2 KO mice. Intervention of D1 dopamine receptor functions or the signaling pathways-related D1 receptors in D2 KO mice produced anti-autistic effects. Together, our results indicate that increased dopamine function in the dorsal striatum promotes autistic-like behaviors and that the dorsal striatum is the neural correlate of ASD core symptoms.

Treatment of acute and subacute dorsal perilunate fracture dislocations

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Levent Kucuk

2014-04-01

Outcomes: Results of the perilunate fracture dislocations treated in acute or subacute phase by open reduction and internal fixation via dorsal approach are satisfactory. There is a strong demand for prospective, randomized studies to compare the results of different treatment modalities. [Hand Microsurg 2014; 3(1.000: 1-7

Effects of organically bound tritium (OBT) on cultured midbrain cells from embryonic mice

International Nuclear Information System (INIS)

Wang Bing; Akihiro Shima; Takeshi Yamada; Keiko Watganabe

1997-01-01

Objective: Four kinds of organically bound tritium compounds (OBT s ) including 3 H-thymidine, 3 H-uridine, 3 H-arginine and 3 H-glutamic acid, were investigated on proliferation and differentiation of cultured mouse embryonic midbrain cells (MBCs). Methods: MBCs were isolated from day 11 embryos, cultured at a high concentration with the medium containing OBT. Results: Differentiation of MBC was more sensitive to radiation than proliferation. Dose-dependent decrease of DNA and protein contents were also observed. The RBE values, ranging from 4.6 to 8.7, of β rays from OBTs were obtained when compared with X-irradiation at their ID50s (inhibitory dose that reduced assessment value by 50% of the control) on inhibition of cell proliferation and differentiation, and on reduction of DNA and protein contents of the cultures. The mixed exposure to X-rays and one kind of OBTs or to any two kinds of OBTs resulted in more efficiently inhibitory effect on differentiation. Conclusions: MBC culture system was more sensitive to beta radiation from OBTs than to X-rays, which resulted in very high RBE values

Patterning of the dorsal-ventral axis in echinoderms: insights into the evolution of the BMP-chordin signaling network.

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François Lapraz

2009-11-01

Full Text Available Formation of the dorsal-ventral axis of the sea urchin embryo relies on cell interactions initiated by the TGFbeta Nodal. Intriguingly, although nodal expression is restricted to the ventral side of the embryo, Nodal function is required for specification of both the ventral and the dorsal territories and is able to restore both ventral and dorsal regions in nodal morpholino injected embryos. The molecular basis for the long-range organizing activity of Nodal is not understood. In this paper, we provide evidence that the long-range organizing activity of Nodal is assured by a relay molecule synthesized in the ventral ectoderm, then translocated to the opposite side of the embryo. We identified this relay molecule as BMP2/4 based on the following arguments. First, blocking BMP2/4 function eliminated the long-range organizing activity of an activated Nodal receptor in an axis rescue assay. Second, we demonstrate that BMP2/4 and the corresponding type I receptor Alk3/6 functions are both essential for specification of the dorsal region of the embryo. Third, using anti-phospho-Smad1/5/8 immunostaining, we show that, despite its ventral transcription, the BMP2/4 ligand triggers receptor mediated signaling exclusively on the dorsal side of the embryo, one of the most extreme cases of BMP translocation described so far. We further report that the pattern of pSmad1/5/8 is graded along the dorsal-ventral axis and that two BMP2/4 target genes are expressed in nested patterns centered on the region with highest levels of pSmad1/5/8, strongly suggesting that BMP2/4 is acting as a morphogen. We also describe the very unusual ventral co-expression of chordin and bmp2/4 downstream of Nodal and demonstrate that Chordin is largely responsible for the spatial restriction of BMP2/4 signaling to the dorsal side. Thus, unlike in most organisms, in the sea urchin, a single ventral signaling centre is responsible for induction of ventral and dorsal cell fates. Finally

Abnormal Ventral and Dorsal Attention Network Activity During Single and Dual Target Detection in Schizophrenia

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Amy M. Jimenez

2016-03-01

Full Text Available Early visual perception and attention are impaired in schizophrenia, and these deficits can be observed on target detection tasks. These tasks activate distinct ventral and dorsal brain networks which support stimulus-driven and goal-directed attention, respectively. We used single and dual target rapid serial visual presentation (RSVP tasks during fMRI with an ROI approach to examine regions within these networks associated with target detection and the attentional blink (AB in 21 schizophrenia outpatients and 25 healthy controls. In both tasks, letters were targets and numbers were distractors. For the dual target task, the second target (T2 was presented at 3 different lags after the first target (T1 (lag1=100ms, lag3=300ms, lag7=700ms. For both single and dual target tasks, patients identified fewer targets than controls. For the dual target task, both groups showed the expected AB effect with poorer performance at lag 3 than at lags 1 or 7, and there was no group by lag interaction. During the single target task, patients showed abnormally increased deactivation of the temporo-parietal junction (TPJ, a key region of the ventral network. When attention demands were increased during the dual target task, patients showed overactivation of the posterior intraparietal cortex, a key dorsal network region, along with failure to deactivate TPJ. Results suggest inefficient and faulty suppression of salience-oriented processing regions, resulting in increased sensitivity to stimuli in general, and difficulty distinguishing targets from non-targets.

Retinal glia promote dorsal root ganglion axon regeneration.

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Barbara Lorber

Full Text Available Axon regeneration in the adult central nervous system (CNS is limited by several factors including a lack of neurotrophic support. Recent studies have shown that glia from the adult rat CNS, specifically retinal astrocytes and Müller glia, can promote regeneration of retinal ganglion cell axons. In the present study we investigated whether retinal glia also exert a growth promoting effect outside the visual system. We found that retinal glial conditioned medium significantly enhanced neurite growth and branching of adult rat dorsal root ganglion neurons (DRG in culture. Furthermore, transplantation of retinal glia significantly enhanced regeneration of DRG axons past the dorsal root entry zone after root crush in adult rats. To identify the factors that mediate the growth promoting effects of retinal glia, mass spectrometric analysis of retinal glial conditioned medium was performed. Apolipoprotein E and secreted protein acidic and rich in cysteine (SPARC were found to be present in high abundance, a finding further confirmed by western blotting. Inhibition of Apolipoprotein E and SPARC significantly reduced the neuritogenic effects of retinal glial conditioned medium on DRG in culture, suggesting that Apolipoprotein E and SPARC are the major mediators of this regenerative response.

Morphology of the dorsal and lateral calcaneocuboid ligaments.

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Dorn-Lange, Nadja V; Nauck, Tanja; Lohrer, Heinz; Arentz, Sabine; Konerding, Moritz A

2008-09-01

The dorsolateral calcaneocuboid ligaments have different configurations. In the literature they are only described as either the dorsal or lateral calcaneocuboid ligament. However, recent reconstructive surgical techniques may benefit from a better understanding of the anatomy. The aims of this study were to classify the morphology and attachments of the dorso-lateral calcaneocuboid ligaments and to determine their dimensions. The dorso-lateral aspects of the calcaneocuboid joint of 30 cadaver feet were dissected to expose the associated ligaments. Further, we evaluated possible bony landmarks of the calcaneus that could imply which shape or course the ligament would have in a specific individual. Our findings showed a wide variety of configurations in shape, number, and attachment sites. A constant dorsal ligament and an additional narrower lateral ligament was detectable in half of the cases. The majority of the dorso-lateral calcaneocuboid ligament-complex had an upward course and fanning out from proximal to distal. No bony predictor for the ligaments' shape or course was found. The dorso-lateral ligament-complex of the calcaneocuboid joint revealed a wide variety of configurations. Better understanding of the anatomy of these ligaments may aid in the anatomic reconstruction of these ligaments.

History and evolution of dorsal onlay urethroplasty for bulbar urethral stricture repair using skin or buccal mucosal grafts.

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Barbagli, G; Lazzeri, M

2007-01-01

OBJECTIVES. To illustrate the history and the evolution over time of bulbar dorsal onlay urethroplasty, comparing outcomes when using buccal mucosa or skin grafts. MATERIALS AND METHODS. Ninety-four patients underwent bulbar urethral reconstruction using two dorsal onlay techniques, namely augmented anastomotic urethroplasty and dorsal onlay graft urethroplasty. Preoperative evaluation included clinical history, physical examination, urine culture, residual urine measurement, uroflowmetry and urethrography. Thirty-four patients underwent augmented anastomotic urethroplasty using penile skin (10 cases) or buccal mucosa (24 cases) grafts. Sixty patients underwent dorsal onlay graft urethroplasty using penile skin (38 cases) or buccal mucosa (22 cases) grafts. Forty-eight out of 94 patients received skin grafts and 46 buccal mucosal grafts. RESULTS. Sixty-four (68%) out of 94 cases were successful, whereas 30 (32%) failed. The 34 augmented anastomotic urethroplasties provided successful outcomes in 24 cases (70.6%), but poor outcomes in 10 (29.4%) cases. The 60 dorsal onlay graft urethroplasty proved to be successful in 42 cases (70%), failing in 18 (30%) cases. Twenty-eight (58.3%) out of 48 penile skin grafts were successful and 20 (41.7%) failed. Thirty-six (78.3%) out of 46 buccal mucosa grafts were successful and 10 (21.7%) failed. The 30 failed cases were then treated with internal urethrotomy in 14 cases (46.7%), perineal urethrostomy in 8 cases (26.7%), two-stage repair in 4 cases (13.3%), and one-stage repair in 4 cases (13.3%). CONCLUSIONS. The dorsal onlay technique used for bulbar urethral stricture repair has changed over time. In our experience, the buccal mucosa seems to be the best substitute graft material for bulbar urethroplasty using dorsal approach.

Complex population response of dorsal putamen neurons predicts the ability to learn.

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Laquitaine, Steeve; Piron, Camille; Abellanas, David; Loewenstein, Yonatan; Boraud, Thomas

2013-01-01

Day-to-day variability in performance is a common experience. We investigated its neural correlate by studying learning behavior of monkeys in a two-alternative forced choice task, the two-armed bandit task. We found substantial session-to-session variability in the monkeys' learning behavior. Recording the activity of single dorsal putamen neurons we uncovered a dual function of this structure. It has been previously shown that a population of neurons in the DLP exhibits firing activity sensitive to the reward value of chosen actions. Here, we identify putative medium spiny neurons in the dorsal putamen that are cue-selective and whose activity builds up with learning. Remarkably we show that session-to-session changes in the size of this population and in the intensity with which this population encodes cue-selectivity is correlated with session-to-session changes in the ability to learn the task. Moreover, at the population level, dorsal putamen activity in the very beginning of the session is correlated with the performance at the end of the session, thus predicting whether the monkey will have a "good" or "bad" learning day. These results provide important insights on the neural basis of inter-temporal performance variability.

Agenesis of the dorsal pancreas: systematic review of a clinical challenge

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Javier A. Cienfuegos

Full Text Available Background: Agenesis of the dorsal pancreas is a rare malformation. Since 1911 and until 2008, 53 cases have been reported. Several authors have recently described the association of this anomaly with neoplasia of the ventral pancreas, thus we performed a systematic review of the literature from 2008 to 2015. Methods: A systematic review of the Medline and ISI Web of Science Databases from 2008 until 2015 was carried out, and 30 articles which met the inclusion criteria were identified that included a total of 53 patients: 7 children and 46 adults. Conclusions: Although dorsal pancreatic agenesis is a rare malformation, given its association with non-alcoholic pancreatitis and neoplasia of the residual pancreas, physicians should maintain an expectant attitude.

Propagation of a dorsal cortical fracture of the third metacarpal bone in two horses

International Nuclear Information System (INIS)

Spurlock, G.H.

1988-01-01

Seemingly, propagation of a dorsal cortical fracture in the third metacarpal bone developed after continued race performance in 2 horses. Historically, both horses had intermittent lameness that had responded to nonsteroidal anti-inflammatory drugs and brief rest periods. However, lameness in both horses had increased in severity. Radiography revealed a dorsal cortical fracture of the third metacarpal bone, with propagation of the fracture plane proximally. Fractures were incomplete and healed with stall rest in both horses

Three-dimensional distribution of sensory stimulation-evoked neuronal activity of spinal dorsal horn neurons analyzed by in vivo calcium imaging.

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Nishida, Kazuhiko; Matsumura, Shinji; Taniguchi, Wataru; Uta, Daisuke; Furue, Hidemasa; Ito, Seiji

2014-01-01

The spinal dorsal horn comprises heterogeneous populations of interneurons and projection neurons, which form neuronal circuits crucial for processing of primary sensory information. Although electrophysiological analyses have uncovered sensory stimulation-evoked neuronal activity of various spinal dorsal horn neurons, monitoring these activities from large ensembles of neurons is needed to obtain a comprehensive view of the spinal dorsal horn circuitry. In the present study, we established in vivo calcium imaging of multiple spinal dorsal horn neurons by using a two-photon microscope and extracted three-dimensional neuronal activity maps of these neurons in response to cutaneous sensory stimulation. For calcium imaging, a fluorescence resonance energy transfer (FRET)-based calcium indicator protein, Yellow Cameleon, which is insensitive to motion artifacts of living animals was introduced into spinal dorsal horn neurons by in utero electroporation. In vivo calcium imaging following pinch, brush, and heat stimulation suggests that laminar distribution of sensory stimulation-evoked neuronal activity in the spinal dorsal horn largely corresponds to that of primary afferent inputs. In addition, cutaneous pinch stimulation elicited activities of neurons in the spinal cord at least until 2 spinal segments away from the central projection field of primary sensory neurons responsible for the stimulated skin point. These results provide a clue to understand neuronal processing of sensory information in the spinal dorsal horn.

Three-dimensional distribution of sensory stimulation-evoked neuronal activity of spinal dorsal horn neurons analyzed by in vivo calcium imaging.

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Kazuhiko Nishida

Full Text Available The spinal dorsal horn comprises heterogeneous populations of interneurons and projection neurons, which form neuronal circuits crucial for processing of primary sensory information. Although electrophysiological analyses have uncovered sensory stimulation-evoked neuronal activity of various spinal dorsal horn neurons, monitoring these activities from large ensembles of neurons is needed to obtain a comprehensive view of the spinal dorsal horn circuitry. In the present study, we established in vivo calcium imaging of multiple spinal dorsal horn neurons by using a two-photon microscope and extracted three-dimensional neuronal activity maps of these neurons in response to cutaneous sensory stimulation. For calcium imaging, a fluorescence resonance energy transfer (FRET-based calcium indicator protein, Yellow Cameleon, which is insensitive to motion artifacts of living animals was introduced into spinal dorsal horn neurons by in utero electroporation. In vivo calcium imaging following pinch, brush, and heat stimulation suggests that laminar distribution of sensory stimulation-evoked neuronal activity in the spinal dorsal horn largely corresponds to that of primary afferent inputs. In addition, cutaneous pinch stimulation elicited activities of neurons in the spinal cord at least until 2 spinal segments away from the central projection field of primary sensory neurons responsible for the stimulated skin point. These results provide a clue to understand neuronal processing of sensory information in the spinal dorsal horn.

Gender moderates the association between dorsal medial prefrontal cortex volume and depressive symptoms in a subclinical sample.

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Carlson, Joshua M; Depetro, Emily; Maxwell, Joshua; Harmon-Jones, Eddie; Hajcak, Greg

2015-08-30

Major depressive disorder is associated with lower medial prefrontal cortex volumes. The role that gender might play in moderating this relationship and what particular medial prefrontal cortex subregion(s) might be implicated is unclear. Magnetic resonance imaging was used to assess dorsal, ventral, and anterior cingulate regions of the medial prefrontal cortex in a normative sample of male and female adults. The Depression, Anxiety, and Stress Scale (DASS) was used to measure these three variables. Voxel-based morphometry was used to test for correlations between medial prefrontal gray matter volume and depressive traits. The dorsal medial frontal cortex was correlated with greater levels of depression, but not anxiety and stress. Gender moderates this effect: in males greater levels of depression were associated with lower dorsal medial prefrontal volumes, but in females no relationship was observed. The results indicate that even within a non-clinical sample, male participants with higher levels of depressive traits tend to have lower levels of gray matter volume in the dorsal medial prefrontal cortex. Our finding is consistent with low dorsal medial prefrontal volume contributing to the development of depression in males. Future longitudinal work is needed to substantiate this possibility. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Dorsal and ventral streams across sensory modalities

Institute of Scientific and Technical Information of China (English)

Anna Sedda; Federica Scarpina

2012-01-01

In this review,we describe the current models of dorsal and ventral streams in vision,audition and touch.Available theories take their first steps from the model of Milner and Goodale,which was developed to explain how human actions can be efficiently carried out using visual information.Since then,similar concepts have also been applied to other sensory modalities.We propose that advances in the knowledge of brain functioning can be achieved through models explaining action and perception patterns independently from sensory modalities.

Burst-generating neurones in the dorsal horn in an in vitro preparation of the turtle spinal cord

DEFF Research Database (Denmark)

Russo, R E; Hounsgaard, J

1996-01-01

1. In transverse slices of the spinal cord of the turtle, intracellular recordings were used to characterize and analyse the responses to injected current and activation of primary afferents in dorsal horn neurones. 2. A subpopulation of neurones, with cell bodies located centrally in the dorsal...

Dorsal approaches to intradural extramedullary tumors of the craniovertebral junction

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D Refai

2010-01-01

Full Text Available Tumors of the craniovertebral junction (CVJ pose significant challenges to cranial and spine surgeons. Familiarity with the complex anatomy and avoidance of injury to neurologic and vascular structures are essential to success. Multiple surgical approaches to address lesions at the CVJ have been promoted, including ventral and dorsal-based trajectories. However, optimal selection of the surgical vector to manage the pathology requires a firm understanding of the limitations and advantages of each approach. The selection of the best surgical trajectory must include several factors, such as obtaining the optimal exposure of the region of interest, avoiding injury to critical neurologic or vascular structures, identification of normal anatomical landmarks, the familiarity and comfort level of the surgeon to the approach, and the need for fixation. This review article focuses on dorsal approaches to the CVJ and the advantages and limitations in managing intradural extramedullary tumors.

Single-prolonged stress induces apoptosis in dorsal raphe nucleus in the rat model of posttraumatic stress disorder

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Liu Dongjuan

2012-11-01

Full Text Available Abstract Introduction Post-traumatic stress disorder (PTSD is an anxiety disorder that develops after exposure to a life-threatening traumatic experience. Meta-analyses of the brainstem showed that midsagittal area of the pons was significantly reduced in patients with PTSD, suggesting a potential apoptosis in dorsal raphe nucleus after single-prolonged stress (SPS. The aim of this study is to investigate whether SPS induces apoptosis in dorsal raphe nucleus in PTSD rats, which may be a possible mechanism of reduced volume of pons and density of gray matter. Methods In this study, rats were randomly divided into 1d, 7d and 14d groups after SPS along with the control group. The apoptosis rate was determined using annexin V-FITC/PI double-labeled flow cytometry (FCM. Levels of Cytochrome c (Cyt-C was examined by Western blotting. Expression of Cyt-C on mitochondria in the dorsal raphe nucleus neuron was determined by enzymohistochemistry under transmission electron microscopy (TEM. The change of thiamine monophosphatase (TMP levels was assessed by enzymohistochemistry under light microscope and TEM. Morphological changes of the ultrastructure of the dorsal raphe nucleus neuron were determined by TEM. Results Apoptotic morphological alterations were observed in dorsal raphe nucleus neuron for all SPS-stimulate groups of rats. The apoptosis rates were significantly increased in dorsal raphe nucleus neuron of SPS rats, along with increased release of cytochrome c from the mitochondria into the cytoplasm, increased expression of Cyt-C and TMP levels in the cytoplasm, which reached to the peak of increase 7 days of SPS. Conclusions The results indicate that SPS induced Cyt-C released from mitochondria into cytosol and apoptosis in dorsal raphe nucleus neuron of rats. Increased TMP in cytoplasm facilitated the clearance of apoptotic cells. We propose that this presents one of the mechanisms that lead to reduced volume of pons and gray matter associated

A New Sail-Backed Styracosternan (Dinosauria: Ornithopoda) from the Early Cretaceous of Morella, Spain.

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Gasulla, José Miguel; Escaso, Fernando; Narváez, Iván; Ortega, Francisco; Sanz, José Luis

2015-01-01

A new styracosternan ornithopod genus and species is here described based on a partial postcranial skeleton and an associated dentary tooth of a single specimen from the Arcillas de Morella Formation (Early Cretaceous, late Barremian) at the Morella locality, (Castellón, Spain). Morelladon beltrani gen. et sp. nov. is diagnosed by eight autapomorphic features. The set of autapomorphies includes: very elongated and vertical neural spines of the dorsal vertebrae, midline keel on ventral surface of the second to fourth sacral vertebrae restricted to the anterior half of the centrum, a posterodorsally inclined medial ridge on the postacetabular process of the ilium that meets its dorsal margin and distal end of the straight ischial shaft laterally expanded, among others. Phylogenetic analyses reveal that the new Iberian form is more closely related to its synchronic and sympatric contemporary European taxa Iguanodon bernissartensis and Mantellisaurus atherfieldensis, known from Western Europe, than to other Early Cretaceous Iberian styracosternans (Delapparentia turolensis and Proa valdearinnoensis). The recognition of Morelladon beltrani gen. et sp. nov. indicates that the Iberian Peninsula was home to a highly diverse medium to large bodied styracosternan assemblage during the Early Cretaceous.

Quadrigeminal plate lipoma presenting with Psychosis: A case ‎report with review of literature

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Sourav Das

2015-12-01

Full Text Available A young patient who presented with headache followed by positive and negative symptoms of psychosis and mutism was sent for the MRI of brain. MRI revealed a lipoma in the quardrigeminal area. We hypothesized that the neuro-vascular encasement of structures located at the upper dorsal midbrain by the lipoma caused the symptoms. A review of the current literature of quadrigeminal lipoma cases with presenting symptoms is provided. Lipoma in quardrigeminal area could give rise to symptoms of psychosis.

Pseudomyopia in a patient with blocked ventriculo-peritoneal shunt--a case report.

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Voon, L W; Goh, K Y; Lim, T H; Tan, K K; Yong, V S

1997-03-01

Accommodative spasm usually encompasses a classical triad of pseudomyopia, esodeviation and pupillary constriction. Accommodative spasm is most often psychogenic in nature; however, it may be associated with other organic diseases of which a rare cause is that of intracranial catheter complications. We report a case of dorsal midbrain syndrome with pseudomyopia in a patient with a blocked ventriculo-peritoneal shunt inserted for aqueductal stenosis. Clinical presentation was unusual in this patient as pseudomyopia occurred with exodeviation and without pupillary constriction.

Inflammatory reaction of the anterior dorsal tongue presumably to sodium lauryl sulfate within toothpastes: a triple case report.

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Brown, Ronald S; Smith, Langston; Glascoe, Alison L

2018-02-01

Sodium lauryl sulfate (SLS), a popular surface active agent ingredient within toothpastes, is known for its foaming action. Surface active agents increase the effectiveness of toothpastes with respect to dental plaque removal. SLS is a known irritant and also has allergenic potential. The authors report 3 patients with oral pain secondary to inflammation of the dorsal anterior tongue. These patients were all using toothpastes with SLS as an ingredient. The dorsal tongue lesions and oral pain resolved upon switching to toothpastes without SLS as an ingredient. Clinicians should be aware of the potential of SLS within toothpastes to cause oral mucosal inflammatory reactions of the anterior dorsal tongue. To our knowledge, these are the first case reports of oral mucosal inflammatory reactions of the anterior dorsal tongue associated with SLS containing toothpastes. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparative study on the 3H-thymidine index of dorsal epidermis, buccal mucosa, and seminal vesicles in senile male rats

International Nuclear Information System (INIS)

Hornstein, O.P.; Schell, H.

1975-01-01

To supplement previous investigations on endogenous fluctuations of DNA synthesis in male rat dorsal epidermis, buccal mucosa and seminal vesicle epithelium from birth to sexual maturity, the labelling indices (L.I.) of these tissues in senile male rats from the same breed, studied under analogous experimental conditions, were evaluated as well as compared to the data obtained from rats in puberal and early mature age. In the dorsal epidermis and buccal mucosa of the old animals the medium L.I. were found to be at about the same level as those measured after puberty. In the aged seminal vesicle epithelium the medium L.I. was found to be decreased. The maintenance of epidermal and buccal DNA synthesis in senile rats as well as the results of previous studies with male rats subjected to castration or long-term administration of cyproteron acetate furnish evidence that a deficiency of testosteron does not diminish the rate of DNA synthesis in epidermis and buccal mucosa. However, from the decreased L.I. in seminal vesicle epithelium a reduced blood level or stimulating capacity, respectively, of testosteron in senile rats can be concluded. Furhtermore, withdrawal of testosteron by orchidectomy or administration of cyproteron acetate is appropriate to suppress significantly the proliferative activity of seminal vesicles epithelium. (orig.) [de

[Trombosis of the dorsal penis vein (of Mondor's phlebitis). Presentation of a new case].

Science.gov (United States)

Rodríguez Faba, O; Parra Muntaner, L; Gómez Cisneros, S C; Martín Benito, J L; Escaf Barmadah, S

2006-01-01

We present a new case of trombosis of the superficial dorsal penis vein called Penile Mondor's disease. The characteristics of the disease are reviewed and the most usual diagnostic and therapeutic methods. The case of a 41 year old man is reviewed who consulted for pain and induration on the proximal part of the penis. After phisical examination and Eco-doppler was made the diagnosis of Mondor's disease. He receibed treatment with non steroidal antiinflamatories and antibiotics. The dorsal vein thrombosis is a rare disease with pain an induration of the dorsal part of the penis. The ethiology can be traumatic, neoplasic, excesive sexual activity or abstinence. Is necesary the diferencial diagnosis with esclerosant linphangitis and the most important imaging is the Eco-doppler. The treatment is based in non steroidal antiinflamatories and antibiotics wit infection. The local aplication of heparine can be useful and the surgery with thrombectomy and resection is for persistent cases.

Dorsal and ventral changes of the occipital vertebrae

International Nuclear Information System (INIS)

Banki, Z.

1981-01-01

Based on his own observation and on the literature, the author discusses various types of calcification in the occipital-cervical region, beginning with those situated dorsally and followed by ventral forms. An attempt is made to classify these changes, depending on their morphology and situation, from an embryological point of view. The pro-atlantal and ante pro-atlanto origin of the occipital vertebrae is discussed. Differentiation depends on appearances. (orig.) [de

Social conflict resolution regulated by two dorsal habenular subregions in zebrafish.

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Chou, Ming-Yi; Amo, Ryunosuke; Kinoshita, Masae; Cherng, Bor-Wei; Shimazaki, Hideaki; Agetsuma, Masakazu; Shiraki, Toshiyuki; Aoki, Tazu; Takahoko, Mikako; Yamazaki, Masako; Higashijima, Shin-ichi; Okamoto, Hitoshi

2016-04-01

When animals encounter conflict they initiate and escalate aggression to establish and maintain a social hierarchy. The neural mechanisms by which animals resolve fighting behaviors to determine such social hierarchies remain unknown. We identified two subregions of the dorsal habenula (dHb) in zebrafish that antagonistically regulate the outcome of conflict. The losing experience reduced neural transmission in the lateral subregion of dHb (dHbL)-dorsal/intermediate interpeduncular nucleus (d/iIPN) circuit. Silencing of the dHbL or medial subregion of dHb (dHbM) caused a stronger predisposition to lose or win a fight, respectively. These results demonstrate that the dHbL and dHbM comprise a dual control system for conflict resolution of social aggression. Copyright © 2016, American Association for the Advancement of Science.

Comparison of dorsal and dorsomedial displacement in evaluation of first ray hypermobility in feet with and without hallux valgus.

Science.gov (United States)

Singh, Dishan; Biz, Carlo; Corradin, Marco; Favero, Laura

2016-06-01

Hypermobility of the first ray, a probable primary cause of hallux valgus, has traditionally been evaluated in the dorsal direction only although the first tarso-metatarsal joint allows movement in a dorso-medial direction. 600 feet, divided according to the presence or absence of hallux valgus, were evaluated for both dorsal and dorso-medial displacement using a Klaue device. In the control group, the mean first ray displacement was 7.2mm (4.2-11.3) in the dorsal direction (sagittal plane) and 8.3mm (4.0-12.6) in the 45° dorso-medial direction. In the hallux valgus group, the mean first ray mobility was 9.8mm (5.2-14.1) in the dorsal direction compared to a mean of 11.0mm (5.9-16.2) in the 45° dorso-medial direction. It is a paradox that hypermobility of the first ray is measured in only a dorsal (vertical) direction whereas a hallux valgus angle and an intermetatarsal angle are only measured in a transverse plane. Furthermore, the weightbearing foot pronates during gait and the first metatarsal is displaced in a dorsomedial direction rather than a pure dorsal direction. It is suggested that measurement hypermobility of the first ray at a 45° dorso-medial direction is more appropriate. Copyright © 2015 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Dorsal root potential produced by a TTX-insensitive micro-circuitry in the turtle spinal cord

DEFF Research Database (Denmark)

Russo, R E; Delgado-Lezama, R; Hounsgaard, J

2000-01-01

1, The mechanisms underlying the dorsal root potential (DRP) were studied in transverse slices of turtle spinal cord. DRPs were evoked by stimulating one filament in a dorsal root and were recorded from another such filament. 2. The DRP evoked at supramaximal stimulus intensity was reduced....... 5. Our results show that part of the DRP is generated by a TTX-resistant, probably non-spiking micro-circuit with separate components mediated by GABA and glutamate....

Two White Spot Syndrome Virus MicroRNAs Target the Dorsal Gene To Promote Virus Infection in Marsupenaeus japonicus Shrimp.

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Ren, Qian; Huang, Xin; Cui, Yalei; Sun, Jiejie; Wang, Wen; Zhang, Xiaobo

2017-04-15

In eukaryotes, microRNAs (miRNAs) serve as regulators of many biological processes, including virus infection. An miRNA can generally target diverse genes during virus-host interactions. However, the regulation of gene expression by multiple miRNAs has not yet been extensively explored during virus infection. This study found that the Spaztle (Spz)-Toll-Dorsal-antilipopolysaccharide factor (ALF) signaling pathway plays a very important role in antiviral immunity against invasion of white spot syndrome virus (WSSV) in shrimp ( Marsupenaeus japonicus ). Dorsal , the central gene in the Toll pathway, was targeted by two viral miRNAs (WSSV-miR-N13 and WSSV-miR-N23) during WSSV infection. The regulation of Dorsal expression by viral miRNAs suppressed the Spz-Toll-Dorsal-ALF signaling pathway in shrimp in vivo , leading to virus infection. Our study contributes novel insights into the viral miRNA-mediated Toll signaling pathway during the virus-host interaction. IMPORTANCE An miRNA can target diverse genes during virus-host interactions. However, the regulation of gene expression by multiple miRNAs during virus infection has not yet been extensively explored. The results of this study indicated that the shrimp Dorsal gene, the central gene in the Toll pathway, was targeted by two viral miRNAs during infection with white spot syndrome virus. Regulation of Dorsal expression by viral miRNAs suppressed the Spz-Toll-Dorsal-ALF signaling pathway in shrimp in vivo , leading to virus infection. Our study provides new insight into the viral miRNA-mediated Toll signaling pathway in virus-host interactions. Copyright © 2017 American Society for Microbiology.

The influence of propofol anesthesia exposure on nonaversive memory retrieval and expression of molecules involved in memory process in the dorsal hippocampus in peripubertal rats.

Science.gov (United States)

Pavković, Željko; Milanović, Desanka; Ruždijić, Sabera; Kanazir, Selma; Pešić, Vesna

2018-06-01

The effects of anesthetic drugs on postoperative cognitive function in children are not well defined and have not been experimentally addressed. The present study aimed to examine the influence of propofol anesthesia exposure on nonaversive hippocampus-dependent learning and biochemical changes involved in memory process in the dorsal hippocampus, in peripubertal rats as the rodent model of periadolescence. The intersession spatial habituation and the novel object recognition tasks were used to assess spatial and nonspatial, nonaversive hippocampus-dependent learning. The exposure to anesthesia was performed after comparably long acquisition phases in both tasks. Behavioral testing lasted for 2 consecutive days (24-hour retention period). Changes in the expression of molecules involved in memory retrieval/reconsolidation were examined in the dorsal hippocampus by Western blot and immunohistochemistry, at the time of behavioral testing. Exposure to propofol anesthesia resulted in inappropriate assessment of spatial novelty at the beginning of the test session and affected continuation of acquisition in the spatial habituation test. The treatment did not affect recognition of the novel object at the beginning of the test session but it attenuated overall preference to novelty, reflecting retrieval of a weak memory. The expression of phosphorylated extracellular signal-regulated kinase 2 (involved in memory retrieval) was decreased while the level of phosphorylated Ca 2+ /calmodulin-dependent protein kinase IIα and early growth response protein 1 (involved in memory reconsolidation) was increased in the dorsal hippocampus. The level of Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog B (neuronal activity indicator) was increased in the dorsal dentate gyrus. Enhanced exploratory activity was still evident in the propofol anesthesia exposure (PAE) group 48 hour after the treatment in both tasks. In peripubertal rats, propofol anesthesia exposure

Progressive neurodegenerative and behavioural changes induced by AAV-mediated overexpression of α-synuclein in midbrain dopamine neurons

DEFF Research Database (Denmark)

Decressac, M; Mattsson, Bente; Lundblad, M

2012-01-01

-synuclein, we have now been able to achieve increased levels of α-synuclein in the transduced midbrain dopamine neurons sufficient to induce profound deficits in motor function, accompanied by reduced expression of proteins involved in dopamine neurotransmission and a time-dependent loss of nigral dopamine......Parkinson's disease (PD) is characterised by the progressive loss of nigral dopamine neurons and the presence of synucleinopathy. Overexpression of α-synuclein in vivo using viral vectors has opened interesting possibilities to model PD-like pathology in rodents. However, the attempts made so far...... have failed to show a consistent behavioural phenotype and pronounced dopamine neurodegeneration. Using a more efficient adeno-associated viral (AAV) vector construct, which includes a WPRE enhancer element and uses the neuron-specific synapsin-1 promoter to drive the expression of human wild-type α...

A potential role for the midbrain in integrating fat-free mass determined energy needs: An H2 (15) O PET study.

Science.gov (United States)

Weise, Christopher M; Thiyyagura, Pradeep; Reiman, Eric M; Chen, Kewei; Krakoff, Jonathan

2015-06-01

Little is known on how sensing of energy needs is centrally represented, integrated, and translated into the behavioral aspects of energy homeostasis. Fat free mass (FFM) is the major determinant of energy expenditure. We investigated how interindividual variances in FFM relate to neuronal activity in humans. Healthy adults (n = 64, 21F/43M; age 31.3 ± 9.1y; percentage of body fat [PFAT] 25.6 ± 10.7%; BMI 30.4 ± 9) underwent a 36h fast and subsequent H(2) (15) O positron emission tomographic (PET) measurement of regional cerebral blood flow (rCBF). Multiple variable regression analysis revealed significant associations of FFM with rCBF within the midbrain [including parts of the periaqueductal gray (PAG), ventral tegmental area (VTA), thalamic and hypothalamic regions], the bilateral parahippocampal region, left anterior cingulate, left insular cortex, right cerebellum, and distinct regions within the temporal and occipital cortex. In contrast, no significant associations were found for fat mass (FM). We investigated the potential functional-anatomical link between FFM and central regulation of food intake by performing a conjunction analysis of FFM and the perceived hunger feelings. This showed a significant overlap within the midbrain PAG. Mediation analysis demonstrated a significant indirect effect of FFM on hunger with PAG rCBF as mediator. Most regions we found to be associated with FFM form part in ascending homeostatic pathways and cortical circuitries implicated in the regulation of basic bodily functions indicating a potential role of these central networks in the integration of FFM determined energy needs. © 2015 Wiley Periodicals, Inc.

Orexin A and Orexin Receptor 1 axonal traffic in dorsal roots at the CNS/PNS interface

Directory of Open Access Journals (Sweden)

Damien eColas

2014-02-01

Full Text Available Hypothalamic orexin/hypocretin neurons send long axonal projections through the dorsal spinal cord in lamina I-II of the dorsal horn at the interface with the peripheral nervous system (PNS. We show that in the dorsal horn OXA fibers colocalize with substance P (SP positive afferents of dorsal root ganglia (DRG neurons known to mediate sensory processing. Further, OR1 is expressed in p75NTR and SP positive DRG neurons, suggesting a potential signaling pathway between orexin and DRG neurons. Interestingly, DRG sensory neurons have a distinctive bifurcating axon where one branch innervates the periphery and the other one the spinal cord (pseudo-unipolar neurons, allowing for potential functional coupling of distinct targets. We observe that OR1 is transported selectively from DRG toward the spinal cord, while OXA is accumulated retrogradely toward the DRG. We hence report a rare situation of asymmetrical neuropeptide receptor distribution between axons projected by a single neuron. This molecular and cellular data are consistent with the role of OXA/OR1 in sensory processing, including DRG neuronal modulation, and support the potential existence of an OX/HCRT circuit between CNS and PNS.

Increased BOLD activation to predator stressor in subiculum and midbrain of amphetamine-sensitized maternal rats.

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Febo, Marcelo; Pira, Ashley S

2011-03-25

Amphetamine, which is known to cause sensitization, potentiates the hormonal and neurobiological signatures of stress and may also increase sensitivity to stress-inducing stimuli in limbic areas. Trimethylthiazoline (5μL TMT) is a chemical constituent of fox feces that evokes innate fear and activates the neuronal and hormonal signatures of stress in rats. We used blood oxygen level dependent (BOLD) MRI to test whether amphetamine sensitization (1mg/kg, i.p. ×3days) in female rats has a lasting effect on the neural response to a stress-evoking stimulus, the scent of a predator, during the postpartum period. The subiculum and dopamine-enriched midbrain VTA/SN of amphetamine-sensitized but not control mothers showed a greater BOLD signal response to predator odor than a control putrid scent. The greater responsiveness of these two brain regions following stimulant sensitization might impact neural processing in response to stressors in the maternal brain. Copyright © 2010 Elsevier B.V. All rights reserved.

Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus off Mexico

Directory of Open Access Journals (Sweden)

Eduardo Morteo

2017-06-01

Full Text Available Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus. In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n = 6, Gulf of California n = 6 and, Gulf of Mexico n = 7 were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p < 0.05 with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species.

Chronic Intermittent Hypoxia Induces Chronic Low-Grade Neuroinflammation in the Dorsal Hippocampus of Mice.

Science.gov (United States)

Sapin, Emilie; Peyron, Christelle; Roche, Frédéric; Gay, Nadine; Carcenac, Carole; Savasta, Marc; Levy, Patrick; Dematteis, Maurice

2015-10-01

Obstructive sleep apnea (OSA) induces cognitive impairment that involves intermittent hypoxia (IH). Because OSA is recognized as a low-grade systemic inflammatory disease and only some patients develop cognitive deficits, we investigated whether IH-related brain consequences shared similar pathophysiology and required additional factors such as systemic inflammation to develop. Nine-week-old male C57BL/6J mice were exposed to 1 day, 6 or 24 w of IH (alternating 21-5% FiO2 every 30 sec, 8 h/day) or normoxia. Microglial changes were assessed in the functionally distinct dorsal (dH) and ventral (vH) regions of the hippocampus using Iba1 immunolabeling. Then the study concerned dH, as vH only tended to be lately affected. Seven proinflammatory and anti-inflammatory cytokine messenger RNA (mRNA) were assessed at all time points using semiquantitative real-time reverse transcription polymerase chain reaction (RT-PCR). Similar mRNA analysis was performed after 6 w IH or normoxia associated for the past 3 w with repeated intraperitoneal low-dose lipopolysaccharide or saline. Chronic (6, 24 w) but not acute IH induced significant microglial changes in dH only, including increased density and morphological features of microglia priming. In dH, acute but not chronic IH increased IL-1β and RANTES/CCL5 mRNA, whereas the other cytokines remained unchanged. In contrast, chronic IH plus lipopolysaccharide increased interleukin (IL)-6 and IL10 mRNA whereas lipopolysaccharide alone did not affect these cytokines. The obstructive sleep apnea component intermittent hypoxia (IH) causes low-grade neuroinflammation in the dorsal hippocampus of mice, including early but transient cytokine elevations, delayed but long-term microglial changes, and cytokine response alterations to lipopolysaccharide inflammatory challenge. These changes may contribute to IH-induced cognitive impairment and pathological brain aging. © 2015 Associated Professional Sleep Societies, LLC.

Lmx1b-targeted cis-regulatory modules involved in limb dorsalization.

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Haro, Endika; Watson, Billy A; Feenstra, Jennifer M; Tegeler, Luke; Pira, Charmaine U; Mohan, Subburaman; Oberg, Kerby C

2017-06-01

Lmx1b is a homeodomain transcription factor responsible for limb dorsalization. Despite striking double-ventral (loss-of-function) and double-dorsal (gain-of-function) limb phenotypes, no direct gene targets in the limb have been confirmed. To determine direct targets, we performed a chromatin immunoprecipitation against Lmx1b in mouse limbs at embryonic day 12.5 followed by next-generation sequencing (ChIP-seq). Nearly 84% ( n =617) of the Lmx1b-bound genomic intervals (LBIs) identified overlap with chromatin regulatory marks indicative of potential cis -regulatory modules (PCRMs). In addition, 73 LBIs mapped to CRMs that are known to be active during limb development. We compared Lmx1b-bound PCRMs with genes regulated by Lmx1b and found 292 PCRMs within 1 Mb of 254 Lmx1b-regulated genes. Gene ontological analysis suggests that Lmx1b targets extracellular matrix production, bone/joint formation, axonal guidance, vascular development, cell proliferation and cell movement. We validated the functional activity of a PCRM associated with joint-related Gdf5 that provides a mechanism for Lmx1b-mediated joint modification and a PCRM associated with Lmx1b that suggests a role in autoregulation. This is the first report to describe genome-wide Lmx1b binding during limb development, directly linking Lmx1b to targets that accomplish limb dorsalization. © 2017. Published by The Company of Biologists Ltd.

Expression of interleukin-1 beta in rat dorsal root ganglia

NARCIS (Netherlands)

Copray, JCVM; Mantingh, [No Value; Brouwer, N; Biber, K; Kust, BM; Liem, RSB; Huitinga, [No Value; Tilders, FJH; Van Dam, AM; Boddeke, HWGM

2001-01-01

The expression of interleukin-lp was examined in dorsal root ganglion (DRG) neurons from adult rats using non-radioactive in Situ hybridization and immunocytochemistry. At all spinal levels, approximately 70% of the DRG neurons appeared to express IL-1 beta mRNA: about 80% of these DRG neurons

The usefulness of contrast material injection at the dorsal vein of the hand in 64-detecter row helical CT coronary angiography

International Nuclear Information System (INIS)

Kawano, Youji; Yakabe, Kazuaki; Urata, Jungo; Eto, Miyuki; Yamaguchi, Hiroichiro

2011-01-01

In 315 cases of multi detector row CT (MDCT) coronary angiography contrast material were injected at the dorsal vein of the hand. Early 168 cases were used 80 ml of 370 mgI/ml contrast material and later 147 cases were used 350-480 mgI/kg contrast material. In all cases contrast material was injected by 4 ml/sec with post injection of 30-40 ml physiologic saline. The attenuation of RCA No.3 and other coronary arteries or coronary artery bypass graft (CABG) graft was measured. In later cases the usefulness of above 300 HU was 95.2%. In all cases the usefulness was 92.6%. (author)

Widespread disruption of functional brain organization in early-onset Alzheimer's disease.

Directory of Open Access Journals (Sweden)

Sofie M Adriaanse

Full Text Available Early-onset Alzheimer's disease (AD patients present a different clinical profile than late-onset AD patients. This can be partially explained by cortical atrophy, although brain organization might provide more insight. The aim of this study was to examine functional connectivity in early-onset and late-onset AD patients. Resting-state fMRI scans of 20 early-onset (<65 years old, 28 late-onset (≥65 years old AD patients and 15 "young" (<65 years old and 31 "old" (≥65 years old age-matched controls were available. Resting-state network-masks were used to create subject-specific maps. Group differences were examined using a non-parametric permutation test, accounting for gray-matter. Performance on five cognitive domains were used in a correlation analysis with functional connectivity in AD patients. Functional connectivity was not different in any of the RSNs when comparing the two control groups (young vs. old controls, which implies that there is no general effect of aging on functional connectivity. Functional connectivity in early-onset AD was lower in all networks compared to age-matched controls, where late-onset AD showed lower functional connectivity in the default-mode network. Functional connectivity was lower in early-onset compared to late-onset AD in auditory-, sensory-motor, dorsal-visual systems and the default mode network. Across patients, an association of functional connectivity of the default mode network was found with visuoconstruction. Functional connectivity of the right dorsal visual system was associated with attention across patients. In late-onset AD patients alone, higher functional connectivity of the sensory-motor system was associated with poorer memory performance. Functional brain organization was more widely disrupted in early-onset AD when compared to late-onset AD. This could possibly explain different clinical profiles, although more research into the relationship of functional connectivity and cognitive

Emotional detachment in psychopathy: Involvement of dorsal default-mode connections.

Science.gov (United States)

Sethi, Arjun; Gregory, Sarah; Dell'Acqua, Flavio; Periche Thomas, Eva; Simmons, Andy; Murphy, Declan G M; Hodgins, Sheilagh; Blackwood, Nigel J; Craig, Michael C

2015-01-01

Criminal psychopathy is defined by emotional detachment [Psychopathy Checklist - Revised (PCL-R) factor 1], and antisocial behaviour (PCL-R factor 2). Previous work has associated antisocial behaviour in psychopathy with abnormalities in a ventral temporo-amygdala-orbitofrontal network. However, little is known of the neural correlates of emotional detachment. Imaging studies have indicated that the 'default-mode network' (DMN), and in particular its dorsomedial (medial prefrontal - posterior cingulate) component, contributes to affective and social processing in healthy individuals. Furthermore, recent work suggests that this network may be implicated in psychopathy. However, no research has examined the relationship between psychopathy, emotional detachment, and the white matter underpinning the DMN. We therefore used diffusion tensor imaging (DTI) tractography in 13 offenders with psychopathy and 13 non-offenders to investigate the relationship between emotional detachment and the microstructure of white matter connections within the DMN. These included the dorsal cingulum (containing the medial prefrontal - posterior cingulate connections of the DMN), and the ventral cingulum (containing the posterior cingulate - medial temporal connections of the DMN). We found that fractional anisotropy (FA) was reduced in the left dorsal cingulum in the psychopathy group (p = .024). Moreover, within this group, emotional detachment was negatively correlated with FA in this tract portion bilaterally (left: r = -.61, p = .026; right: r = -.62, p = .023). These results suggest the importance of the dorsal DMN in the emotional detachment observed in individuals with psychopathy. We propose a 'dual-network' model of white matter abnormalities in the disorder, which incorporates these with previous findings. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neural retina-specific Aldh1a1 controls dorsal choroidal vascular development via Sox9 expression in retinal pigment epithelial cells.

Science.gov (United States)

Goto, So; Onishi, Akishi; Misaki, Kazuyo; Yonemura, Shigenobu; Sugita, Sunao; Ito, Hiromi; Ohigashi, Yoko; Ema, Masatsugu; Sakaguchi, Hirokazu; Nishida, Kohji; Takahashi, Masayo

2018-04-03

VEGF secreted from retinal pigment epithelial (RPE) cells is responsible for the choroidal vascular development; however, the molecular regulatory mechanism is unclear. We found that Aldh1a1 -/- mice showed choroidal hypoplasia with insufficient vascularization in the dorsal region, although Aldh1a1, an enzyme that synthesizes retinoic acids (RAs), is expressed in the dorsal neural retina, not in the RPE/choroid complex. The level of VEGF in the RPE/choroid was significantly decreased in Aldh1a1 -/- mice, and RA-dependent enhancement of VEGF was observed in primary RPE cells. An RA-deficient diet resulted in dorsal choroidal hypoplasia, and simple RA treatment of Aldh1a1 -/- pregnant females suppressed choroid hypoplasia in their offspring. We also found downregulation of Sox9 in the dorsal neural retina and RPE of Aldh1a1 -/- mice and RPE-specific disruption of Sox9 phenocopied Aldh1a1 -/- choroidal development. These results suggest that RAs produced by Aldh1a1 in the neural retina directs dorsal choroidal vascular development via Sox9 upregulation in the dorsal RPE cells to enhance RPE-derived VEGF secretion. © 2018, Goto et al.

Auditory midbrain processing is differentially modulated by auditory and visual cortices: An auditory fMRI study.

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Gao, Patrick P; Zhang, Jevin W; Fan, Shu-Juan; Sanes, Dan H; Wu, Ed X

2015-12-01

The cortex contains extensive descending projections, yet the impact of cortical input on brainstem processing remains poorly understood. In the central auditory system, the auditory cortex contains direct and indirect pathways (via brainstem cholinergic cells) to nuclei of the auditory midbrain, called the inferior colliculus (IC). While these projections modulate auditory processing throughout the IC, single neuron recordings have samples from only a small fraction of cells during stimulation of the corticofugal pathway. Furthermore, assessments of cortical feedback have not been extended to sensory modalities other than audition. To address these issues, we devised blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) paradigms to measure the sound-evoked responses throughout the rat IC and investigated the effects of bilateral ablation of either auditory or visual cortices. Auditory cortex ablation increased the gain of IC responses to noise stimuli (primarily in the central nucleus of the IC) and decreased response selectivity to forward species-specific vocalizations (versus temporally reversed ones, most prominently in the external cortex of the IC). In contrast, visual cortex ablation decreased the gain and induced a much smaller effect on response selectivity. The results suggest that auditory cortical projections normally exert a large-scale and net suppressive influence on specific IC subnuclei, while visual cortical projections provide a facilitatory influence. Meanwhile, auditory cortical projections enhance the midbrain response selectivity to species-specific vocalizations. We also probed the role of the indirect cholinergic projections in the auditory system in the descending modulation process by pharmacologically blocking muscarinic cholinergic receptors. This manipulation did not affect the gain of IC responses but significantly reduced the response selectivity to vocalizations. The results imply that auditory cortical

[Case of surgical treatment for giant hemangioblastoma in the dorsal medulla oblongata].

Science.gov (United States)

Kamoshima, Yuuta; Terasaka, Shunsuke; Shimoda, Yusuke; Kobayashi, Hiroyuki; Kuroda, Satoshi; Asano, Takeshi; Yamaguchi, Shigeru; Murata, Junichi; Houkin, Kiyohiro

2012-03-01

Hemangioblastoma in the medulla oblongata is a relatively rare tumor. We present the case of a giant hemangioblastoma occurring in the dorsal medulla oblongata. A 33-year-old man with no neurological symptoms was diagnosed with a hemangioblastoma in the dorsal medulla oblongata, and opted for observation in the outpatient department. After 22 months of observation time, MRI scans showed rapid local tumor progression and obstructive hydrocephalus. At this point, he presented with mild dysphagia as a preoperative neurological deficit. Total surgical removal of the tumor was performed after temporary ventricle drainage and preoperative embolization of the feeding artery. Postoperatively, he became fully conscious but developed bulbar palsy followed by tracheostomy. During the 12 months of postoperative follow-up, severe dysphagia was still present.

Concurrent TMS-fMRI Reveals Interactions between Dorsal and Ventral Attentional Systems

DEFF Research Database (Denmark)

Leitao, Joana; Thielscher, Axel; Tuennerhoff, Johannes

2015-01-01

interactively in this process. This fMRI study used concurrent transcranial magnetic stimulation (TMS) as a causal perturbation approach to investigate the interactions between dorsal and ventral attentional systems and sensory processing areas. In a sustained spatial attention paradigm, human participants......Adaptive behavior relies on combining bottom-up sensory inputs with top-down control signals to guide responses in line with current goals and task demands. Over the past decade, accumulating evidence has suggested that the dorsal and ventral frontoparietal attentional systems are recruited......-TMS relative to Sham-TMS increased activation in the parietal cortex regardless of sensory stimulation, confirming the neural effectiveness of TMS stimulation. Visual targets increased activations in the anterior insula, a component of the ventral attentional system responsible for salience detection...

Light and electron microscopy of contacts between primary afferent fibres and neurones with axons ascending the dorsal columns of the feline spinal cord.

Science.gov (United States)

Maxwell, D J; Koerber, H R; Bannatyne, B A

1985-10-01

In addition to primary afferent fibres, the dorsal columns of the cat spinal cord contain ascending second-order axons which project to the dorsal column nuclei. The aim of the present study was to obtain morphological evidence that certain primary afferent axons form monosynaptic contacts with cells of origin of this postsynaptic dorsal column pathway. In ten adult cats, neurones with axons ascending the dorsal columns were retrogradely labelled with horseradish peroxidase using a pellet implantation method in the thoracic dorsal columns. In the lumbosacral regions of the same animals, primary afferent fibres were labelled intra-axonally with ionophoretic application of horseradish peroxidase. Tissue containing labelled axons was prepared for light and combined light and electron microscopy. Ultrastructural examination demonstrated that slowly adapting (Type I), hair follicle, Pacinian corpuscle and group Ia muscle spindle afferents formed monosynaptic contacts with labelled cells and light microscopical analysis suggested that they also received monosynaptic input from rapidly adapting (Krause) afferents. This evidence suggests that sensory information from large-diameter cutaneous and muscle spindle afferent fibres is conveyed disynaptically via the postsynaptic dorsal column pathway to the dorsal column nuclei. Some of the input to this pathway is probably modified in the spinal cord as the majority of primary afferent boutons forming monosynaptic contacts were postsynaptic to other axon terminals. The postsynaptic dorsal column system appears to constitute a major somatosensory pathway in the cat.

Anatomy of the dorsal default-mode network in conduct disorder: Association with callous-unemotional traits.

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Sethi, Arjun; Sarkar, Sagari; Dell'Acqua, Flavio; Viding, Essi; Catani, Marco; Murphy, Declan G M; Craig, Michael C

2018-04-01

We recently reported that emotional detachment in adult psychopathy was associated with structural abnormalities in the dorsal 'default-mode' network (DMN). However, it is unclear whether these differences are present in young people at risk of psychopathy. The most widely recognised group at risk for psychopathy are children/adolescents with conduct disorder (CD) and callous-unemotional (CU) traits. We therefore examined the microstructure of the dorsal DMN in 27 CD youths (14-with/13-without CU traits) compared to 16 typically developing controls using DTI tractography. Both CD groups had significantly (p < 0.025) reduced dorsal DMN radial diffusivity compared to controls. In those with diagnostically significant CU traits, exploratory analyses (uncorrected for multiple comparisons) suggested that radial diffusivity was negatively correlated with CU severity (Left: rho = -0.68, p = 0.015). These results suggest that CD youths have microstructural abnormalities in the same network as adults with psychopathy. Further, the association with childhood/adolescent measures of emotional detachment (CU traits) resembles the relationship between emotional detachment and network microstructure in adult psychopaths. However, these changes appear to occur in opposite directions - with increased myelination in adolescent CD but reduced integrity in adult psychopathy. Collectively, these findings suggest that developmental abnormalities in dorsal DMN may play a role in the emergence of psychopathy. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

The influence of superlethal γ-radiation doses on the content and metabolism of serotonin in the rat brain

International Nuclear Information System (INIS)

Silina, A.G.; Sverdlov, A.G.

1987-01-01

As early as 60 min after γ-irradiation of Wistar rats with a dose of 150 Gy the content of serotonin and 5-hydroxyindoleacetic acid decreases in the midbrain, hippocampus, and cerebral hemisphere cortex. The decrease is most pronounced in the midbrain where serotoninergic neurons are located. The changes are accumulated during the first 24 h following irradiation h

Select overexpression of homer1a in dorsal hippocampus impairs spatial working memory

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Tansu Celikel

2007-10-01

Full Text Available Long Homer proteins forge assemblies of signaling components involved in glutamate receptor signaling in postsynaptic excitatory neurons, including those underlying synaptic transmission and plasticity. The short immediate-early gene (IEG Homer1a can dynamically uncouple these physical associations by functional competition with long Homer isoforms. To examine the consequences of Homer1amediated uncoupling for synaptic plasticity and behavior, we generated forebrain-specific tetracycline (tet controlled expression of Venus-tagged Homer1a (H1aV in mice. We report that sustained overexpression of H1aV impaired spatial working but not reference memory. Most notably, a similar impairment was observed when H1aV expression was restricted to the dorsal hippocampus (HP, which identifies this structure as the principal cortical area for spatial working memory. Interestingly, H1aV overexpression also abolished maintenance of CA3-CA1 long-term potentiation (LTP. These impairments, generated by sustained high Homer1a levels, identify a requirement for long Homer forms in synaptic plasticity and temporal encoding of spatial memory.

A radiologic study on the urinary bladder following dorsal and ...

African Journals Online (AJOL)

Pneumocystography and positive contrast cystography using solutrast® were carried out immediately after surgery and on the second operative day following dorsal and ventral cystotomy in 22 adult mongrel dogs. In all the radiographs, there was no contrast observed in the abdominal cavity and the apex of the bladder had ...

Response properties of neighboring neurons in the auditory midbrain for pure-tone stimulation: a tetrode study.

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Seshagiri, Chandran V; Delgutte, Bertrand

2007-10-01

The complex anatomical structure of the central nucleus of the inferior colliculus (ICC), the principal auditory nucleus in the midbrain, may provide the basis for functional organization of auditory information. To investigate this organization, we used tetrodes to record from neighboring neurons in the ICC of anesthetized cats and studied the similarity and difference among the responses of these neurons to pure-tone stimuli using widely used physiological characterizations. Consistent with the tonotopic arrangement of neurons in the ICC and reports of a threshold map, we found a high degree of correlation in the best frequencies (BFs) of neighboring neurons, which were mostly binaural beats. However, the characteristic phases (CPs) of neighboring neurons revealed a significant correlation. Because the CP is related to the neural mechanisms generating the ITD sensitivity, this result is consistent with segregation of inputs to the ICC from the lateral and medial superior olives.

Abnormal global processing along the dorsal visual pathway in autism: a possible mechanism for weak visuospatial coherence?

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Pellicano, Elizabeth; Gibson, Lisa; Maybery, Murray; Durkin, Kevin; Badcock, David R

2005-01-01

Frith and Happe (Frith, U., & Happe, F. (1994). Autism: Beyond theory of mind. Cognition, 50, 115-132) argue that individuals with autism exhibit 'weak central coherence': an inability to integrate elements of information into coherent wholes. Some authors have speculated that a high-level impairment might be present in the dorsal visual pathway in autism, and furthermore, that this might account for weak central coherence, at least at the visuospatial level. We assessed the integrity of the dorsal visual pathway in children diagnosed with an autism spectrum disorder (ASD), and in typically developing children, using two visual tasks, one examining functioning at higher levels of the dorsal cortical stream (Global Dot Motion (GDM)), and the other assessing lower-level dorsal stream functioning (Flicker Contrast Sensitivity (FCS)). Central coherence was tested using the Children's Embedded Figures Test (CEFT). Relative to the typically developing children, the children with ASD had shorter CEFT latencies and higher GDM thresholds but equivalent FCS thresholds. Additionally, CEFT latencies were inversely related to GDM thresholds in the ASD group. These outcomes indicate that the elevated global motion thresholds in autism are the result of high-level impairments in dorsal cortical regions. Weak visuospatial coherence in autism may be in the form of abnormal cooperative mechanisms in extra-striate cortical areas, which might contribute to differential performance when processing stimuli as Gestalts, including both dynamic (i.e., global motion perception) and static (i.e., disembedding performance) stimuli.

A double dissociation of dorsal and ventral hippocampal function on a learning and memory task mediated by the dorso-lateral striatum.

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McDonald, Robert J; Jones, Jana; Richards, Blake; Hong, Nancy S

2006-09-01

The objectives of this research were to further delineate the neural circuits subserving proposed memory-based behavioural subsystems in the hippocampal formation. These studies were guided by anatomical evidence showing a topographical organization of the hippocampal formation. Briefly, perpendicular to the medial/lateral entorhinal cortex division there is a second system of parallel circuits that separates the dorsal and ventral hippocampus. Recent work from this laboratory has provided evidence that the hippocampus incidentally encodes a context-specific inhibitory association during acquisition of a visual discrimination task. One question that emerges from this dataset is whether the dorsal or ventral hippocampus makes a unique contribution to this newly described function. Rats with neurotoxic lesions of the dorsal or ventral hippocampus were assessed on the acquisition of the visual discrimination task. Following asymptotic performance they were given reversal training in either the same or a different context from the original training. The results showed that the context-specific inhibition effect is mediated by a circuit that includes the ventral but not the dorsal hippocampus. Results from a control procedure showed that rats with either dorso-lateral striatum damage or dorsal hippocampal lesions were impaired on a tactile/spatial discrimination. Taken together, the results represent a double dissociation of learning and memory function between the ventral and dorsal hippocampus. The formation of an incidental inhibitory association was dependent on ventral but not dorsal hippocampal circuitry, and the opposite dependence was found for the spatial component of a tactile/spatial discrimination.

A preliminary study of the sensory distribution of the penile dorsal and ventral nerves: implications for effective penile block for circumcision.

LENUS (Irish Health Repository)

Long, Ronan M

2012-01-31

OBJECTIVE: To determine the sensory innervation of the penis, as regional anaesthesia is often used either for postoperative analgesia or as the sole anaesthetic technique for circumcision. Since first described in 1978 the dorsal penile nerve block has become the standard technique, but some blocks are ineffective; a better understanding of the sensory innervation of the penis might improve the efficacy of the dorsal penile block technique. PATIENTS AND METHODS: In 13 men undergoing circumcision with local anaesthetic, cutaneous sensation was tested before and after infiltration of the dorsal aspect of the penis, and then again after infiltration of the ventral aspect. The area of anaesthesia was mapped using pin-prick sensation. RESULTS: Ten of the 13 patients showed a similar pattern of sensory distribution. After the dorsal block, the dorsal aspect of the shaft of the penis and glans penis became insensate. The ventral aspect of the shaft remained sensate up to and including the frenulum. After successful ventral infiltration all sensate areas became insensate and circumcision proceeded. In one case the frenulum and distal ventral foreskin was anaesthetized after the dorsal block and ventral infiltration was not required. No patient experienced pain during circumcision. CONCLUSION: For consistently successful regional anaesthesia of the foreskin in circumcision, a dorsal block must be used. This should be combined with ventral infiltration at the site of incision. This method will avoid inconsistencies and allow pain-free circumcision using local anaesthesia in most men.

SCANNING ELECTRON MICROSCOPY STUDY OF THE DORSAL SURFACE OF THE TONGUE IN Chaetophractus vellerosus (MAMMALIA, DASYPODIDAE)

OpenAIRE

Estecondo, Silvia; Codón, Stella Maris; Casanave, Emma Beatriz

2001-01-01

The characteristics of the dorsal surface of Chaetophractus vellerosus tongue were studied by scanning electron microscopy. Simple or branched filiform, fungiform and vallate papillae are described. Simple conical filiform papillae appear in the apex, lateral edges and posterior third, caudally to the circumvallated ones. The branched papillae are densely distributed all over the dorsal surface of the lingual body. Fungiform ones are scattered among the branched filiform papillae. In the post...

Responses of spinal dorsal horn neurons to foot movements in rats with a sprained ankle

OpenAIRE

Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon; Chung, Jin Mo

2011-01-01

Acute ankle injuries are common problems and often lead to persistent pain. To investigate the underlying mechanism of ankle sprain pain, the response properties of spinal dorsal horn neurons were examined after ankle sprain. Acute ankle sprain was induced manually by overextending the ankle of a rat hindlimb in a direction of plantarflexion and inversion. The weight-bearing ratio (WBR) of the affected foot was used as an indicator of pain. Single unit activities of dorsal horn neurons in res...

Uso terapêutico da radiofrequência pulsátil no gânglio dorsal da raiz de L2 na lombalgia discogênica Uso terapéutico de la radiofrecuencia pulsátil en el ganglio dorsal de la raíz de L2 en la lumbalgia discogénica Pulsed radiofrequency on L2 dorsal root ganglion as a therapeutic method for lumbar discogenic pain

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Fabrício Dias Assis

2009-06-01

Full Text Available OBJETIVO: Avaliar a eficácia da radiofrequência pulsátil sobre o gânglio da raiz dorsal de L2 no tratamento dos pacientes com lombalgia discogênica. MÉTODOS: Realizou-se análise retrospectiva de 50 pacientes portadores de lombalgia crônica discogênica atendidos no período de janeiro de 2004 a julho de 2007. O processo diagnóstico foi constituído por exame físico, ressonância magnética e bloqueio diagnóstico do gânglio da raiz dorsal de L2. Todos os pacientes foram submetidos à radiofrequência pulsátil no gânglio da raiz dorsal de L2 e acompanhados por, no mínimo, 12 meses. A intensidade de dor foi medida pela escala visual analógica (EVA de dor. RESULTADOS: A análise estatística mostrou melhora significativa da intensidade de dor (pOBJETIVO: evaluar la eficacia de la radiofrecuencia pulsátil sobre el ganglio de la raíz dorsal de L2 en el tratamiento de los pacientes con lumbalgia discogénica. MÉTODOS: fue realizado un análisis retrospectivo de 50 pacientes portadores de lumbalgia crónica discogénica, atendidos en el periodo de Enero de 2004 a Julio de 2007. El proceso diagnóstico constó de un examen físico, resonancia magnética y bloqueo diagnóstico del ganglio de la raíz dorsal de L2. Todos los pacientes fueron sometidos a la radiofrecuencia pulsátil en el ganglio de la raíz dorsal de L2 y seguidos por 12 meses, como mínimo. La intensidad del dolor fue medida por la escala visual analógica del dolor. RESULTADOS: el análisis estadístico mostró mejoría significativa de la intensidad del dolor (pOBJECTIVE: to evaluate the effectiveness of pulsate radio-frequency on L2 dorsal root ganglion for chronic discogenic low back pain. Of L2 in the treatment of the patient with discogenic low back pain. METHODS: Between January 2004 and July 2007, 50 patients with diagnosis of low back discogenic pain were retrospectively assessed based on physical examination, magnetic resonance imaging findings and selective L

The brain's dorsal route for speech represents word meaning: evidence from gesture.

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Josse, Goulven; Joseph, Sabine; Bertasi, Eric; Giraud, Anne-Lise

2012-01-01

The dual-route model of speech processing includes a dorsal stream that maps auditory to motor features at the sublexical level rather than at the lexico-semantic level. However, the literature on gesture is an invitation to revise this model because it suggests that the premotor cortex of the dorsal route is a major site of lexico-semantic interaction. Here we investigated lexico-semantic mapping using word-gesture pairs that were either congruent or incongruent. Using fMRI-adaptation in 28 subjects, we found that temporo-parietal and premotor activity during auditory processing of single action words was modulated by the prior audiovisual context in which the words had been repeated. The BOLD signal was suppressed following repetition of the auditory word alone, and further suppressed following repetition of the word accompanied by a congruent gesture (e.g. ["grasp" + grasping gesture]). Conversely, repetition suppression was not observed when the same action word was accompanied by an incongruent gesture (e.g. ["grasp" + sprinkle]). We propose a simple model to explain these results: auditory and visual information converge onto premotor cortex where it is represented in a comparable format to determine (in)congruence between speech and gesture. This ability of the dorsal route to detect audiovisual semantic (in)congruence suggests that its function is not restricted to the sublexical level.

Selective Entrainment of Theta Oscillations in the Dorsal Stream Causally Enhances Auditory Working Memory Performance.

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Albouy, Philippe; Weiss, Aurélien; Baillet, Sylvain; Zatorre, Robert J

2017-04-05

The implication of the dorsal stream in manipulating auditory information in working memory has been recently established. However, the oscillatory dynamics within this network and its causal relationship with behavior remain undefined. Using simultaneous MEG/EEG, we show that theta oscillations in the dorsal stream predict participants' manipulation abilities during memory retention in a task requiring the comparison of two patterns differing in temporal order. We investigated the causal relationship between brain oscillations and behavior by applying theta-rhythmic TMS combined with EEG over the MEG-identified target (left intraparietal sulcus) during the silent interval between the two stimuli. Rhythmic TMS entrained theta oscillation and boosted participants' accuracy. TMS-induced oscillatory entrainment scaled with behavioral enhancement, and both gains varied with participants' baseline abilities. These effects were not seen for a melody-comparison control task and were not observed for arrhythmic TMS. These data establish theta activity in the dorsal stream as causally related to memory manipulation. VIDEO ABSTRACT. Copyright © 2017 Elsevier Inc. All rights reserved.

A possible role of midbrain dopamine neurons in short- and long-term adaptation of saccades to position-reward mapping.

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Takikawa, Yoriko; Kawagoe, Reiko; Hikosaka, Okihide

2004-10-01

Dopamine (DA) neurons respond to sensory stimuli that predict reward. To understand how DA neurons acquire such ability, we trained monkeys on a one-direction-rewarded version of memory-guided saccade task (1DR) only when we recorded from single DA neurons. In 1DR, position-reward mapping was changed across blocks of trials. In the early stage of training of 1DR, DA neurons responded to reward delivery; in the later stages, they responded predominantly to the visual cue that predicted reward or no reward (reward predictor) differentially. We found that such a shift of activity from reward to reward predictor also occurred within a block of trials after position-reward mapping was altered. A main effect of long-term training was to accelerate the within-block reward-to-predictor shift of DA neuronal responses. The within-block shift appeared first in the intermediate stage, but was slow, and DA neurons often responded to the cue that indicated reward in the preceding block. In the advanced stage, the reward-to-predictor shift occurred quickly such that the DA neurons' responses to visual cues faithfully matched the current position-reward mapping. Changes in the DA neuronal responses co-varied with the reward-predictive differentiation of saccade latency both in short-term (within-block) and long-term adaptation. DA neurons' response to the fixation point also underwent long-term changes until it occurred predominantly in the first trial within a block. This might trigger a switch between the learned sets. These results suggest that midbrain DA neurons play an essential role in adapting oculomotor behavior to frequent switches in position-reward mapping.

Widely scattered CT lesions in the midbrain and the pons in a case of neuro-Behcet's syndrome

International Nuclear Information System (INIS)

Kuroiwa, Yoshiyuki; Tohgi, Hideo; Kanayama, Hiroumi; Fujimori, Masaki; Aoki, Hidehiko

1985-01-01

We report on a 30-year-old man with neuro-Behcet's disease. His main neurologic symptoms and signs included headache, alternating hemiparesis, dysarthria, and truncal ataxia. Lumbar puncture demonstrated an elevated pressure, pleocytosis, and an increased protein concentration. Intravenous betamethasone produced a rapid and sustained improvement, without recurrence for two years. Widely scattered foci of small, low-density lesions were disclosed in the midbrain and the pons on a cranial CT scan with 2.5 mm thin-cut slices to enable us to focus on the brainstem. Such CT lesions are consistent with the neuropathological features of this illness, which shows a tendency for brainstem lesions to predominate; these lesions probably represent necrotic areas secondary to vasculitis. Brainstem CT studies with thin-cut slices may be an important diagnostic aid in patients suspected of having neuro-Behcet's disease. (author)

Liposarcome dorsal: aspect clinique rare

Science.gov (United States)

Agbessi, Odry; Arrob, Adil; Fiqhi, Kamal; Khalfi, Lahcen; Nassih, Mohammed; El Khatib, Karim

2015-01-01

Décrit la première fois par Virchow en 1860, le liposarcome est une tumeur mésenchymateuse rare. Cette rareté est relative car les liposarcomes représentent quand même 14 à 18% de l'ensemble des tumeurs malignes des parties molles et ils constituent le plus fréquent des sarcomes des parties molles. Pour la majorité des auteurs, il ne se développerait jamais sur un lipome ou une lipomatose préexistant. Nous rapportons un cas de volumineux liposarcome de la face dorsale du tronc. L'histoire de la maladie, l'aspect clinique inhabituel « de tumeur dans tumeur », l'aspect de la pièce opératoire nous fait évoquer la possibilité de la transformation maligne d'un lipome bénin préexistant. PMID:26113914

Frequency-specific attentional modulation in human primary auditory cortex and midbrain.

Science.gov (United States)

Riecke, Lars; Peters, Judith C; Valente, Giancarlo; Poser, Benedikt A; Kemper, Valentin G; Formisano, Elia; Sorger, Bettina

2018-07-01

Paying selective attention to an audio frequency selectively enhances activity within primary auditory cortex (PAC) at the tonotopic site (frequency channel) representing that frequency. Animal PAC neurons achieve this 'frequency-specific attentional spotlight' by adapting their frequency tuning, yet comparable evidence in humans is scarce. Moreover, whether the spotlight operates in human midbrain is unknown. To address these issues, we studied the spectral tuning of frequency channels in human PAC and inferior colliculus (IC), using 7-T functional magnetic resonance imaging (FMRI) and frequency mapping, while participants focused on different frequency-specific sounds. We found that shifts in frequency-specific attention alter the response gain, but not tuning profile, of PAC frequency channels. The gain modulation was strongest in low-frequency channels and varied near-monotonically across the tonotopic axis, giving rise to the attentional spotlight. We observed less prominent, non-tonotopic spatial patterns of attentional modulation in IC. These results indicate that the frequency-specific attentional spotlight in human PAC as measured with FMRI arises primarily from tonotopic gain modulation, rather than adapted frequency tuning. Moreover, frequency-specific attentional modulation of afferent sound processing in human IC seems to be considerably weaker, suggesting that the spotlight diminishes toward this lower-order processing stage. Our study sheds light on how the human auditory pathway adapts to the different demands of selective hearing. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Dorsal medial prefrontal cortex contributes to conditioned taste aversion memory consolidation and retrieval.

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Gonzalez, Maria Carolina; Villar, Maria Eugenia; Igaz, Lionel M; Viola, Haydée; Medina, Jorge H

2015-12-01

The medial prefrontal cortex (mPFC) is known for its role in decision making and memory processing, including the participation in the formation of extinction memories. However, little is known regarding its contribution to aversive memory consolidation. Here we demonstrate that neural activity and protein synthesis are required in the dorsal mPFC for memory formation of a conditioned taste aversion (CTA) task and that this region is involved in the retrieval of recent and remote long-term CTA memory. In addition, both NMDA receptor and CaMKII activity in dorsal mPFC are needed for CTA memory consolidation, highlighting the complexity of mPFC functions. Copyright © 2015 Elsevier Inc. All rights reserved.

A deepwater fish with 'lightsabers'--dorsal spine-associated luminescence in a counterilluminating lanternshark.

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Claes, Julien M; Dean, Mason N; Nilsson, Dan-Eric; Hart, Nathan S; Mallefet, Jérôme

2013-01-01

We report the discovery of light organs (photophores) adjacent to the dorsal defensive spines of a small deep-sea lanternshark (Etmopterus spinax). Using a visual modeling based on in vivo luminescence recordings we show that this unusual light display would be detectable by the shark's potential predators from several meters away. We also demonstrate that the luminescence from the spine-associated photophores (SAPs) can be seen through the mineralized spines, which are partially translucent. These results suggest that the SAPs function, either by mimicking the spines' shape or by shining through them, as a unique visual deterrent for predators. This conspicuous dorsal warning display is a surprising complement to the ventral luminous camouflage (counterillumination) of the shark.

Early development of Ensatina eschscholtzii: an amphibian with a large, yolky egg

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Collazo Andres

2010-08-01

Full Text Available Abstract Background Comparative analyses between amphibians, concentrating on the cellular mechanisms of morphogenesis, reveal a large variability in the early developmental processes that were thought to be conserved during evolution. Increased egg size is one factor that could have a strong effect on early developmental processes such as cleavage pattern and gastrulation. Salamanders of the family Plethodontidae are particularly appropriate for such comparative studies because the species have eggs of varying size, including very large yolky eggs. Results In this paper, we describe for the first time the early development (from fertilization through neurulation of the plethodontid salamander Ensatina eschscholtzii. This species has one of the largest eggs known for an amphibian, with a mean ± SD diameter of 6 ± 0.43 mm (range 5.3-6.9; n = 17 eggs. Cleavage is meroblastic until approximately the 16-cell stage (fourth or fifth cleavage. At the beginning of gastrulation, the blastocoel roof is one cell thick, and the dorsal lip of the blastopore forms below the equator of the embryo. The ventral lip of the blastopore forms closer to the vegetal pole, and relatively little involution occurs during gastrulation. Cell migration is visible through the transparent blastocoel roof of the gastrula. At the end of gastrulation, a small archenteron spreading dorsally from the blastopore represents the relatively small and superficial area of the egg where early embryonic axis formation occurs. The resulting pattern is similar to the embryonic disk described for one species of anuran. Conclusions Comparisons with the early development of other species of amphibians suggest that an evolutionary increase in egg size can result in predictable changes in the patterns and rate of early development, but mainly within an evolutionary lineage.

Top-Down Effect of Direct Current Stimulation on the Nociceptive Response of Rats.

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Luiz Fabio Dimov

Full Text Available Transcranial direct current stimulation (tDCS is an emerging, noninvasive technique of neurostimulation for treating pain. However, the mechanisms and pathways involved in its analgesic effects are poorly understood. Therefore, we investigated the effects of direct current stimulation (DCS on thermal and mechanical nociceptive thresholds and on the activation of the midbrain periaqueductal gray (PAG and the dorsal horn of the spinal cord (DHSC in rats; these central nervous system areas are associated with pain processing. Male Wistar rats underwent cathodal DCS of the motor cortex and, while still under stimulation, were evaluated using tail-flick and paw pressure nociceptive tests. Sham stimulation and naive rats were used as controls. We used a randomized design; the assays were not blinded to the experimenter. Immunoreactivity of the early growth response gene 1 (Egr-1, which is a marker of neuronal activation, was evaluated in the PAG and DHSC, and enkephalin immunoreactivity was evaluated in the DHSC. DCS did not change the thermal nociceptive threshold; however, it increased the mechanical nociceptive threshold of both hind paws compared with that of controls, characterizing a topographical effect. DCS decreased the Egr-1 labeling in the PAG and DHSC as well as the immunoreactivity of spinal enkephalin. Altogether, the data suggest that DCS disinhibits the midbrain descending analgesic pathway, consequently inhibiting spinal nociceptive neurons and causing an increase in the nociceptive threshold. This study reinforces the idea that the motor cortex participates in the neurocircuitry that is involved in analgesia and further clarifies the mechanisms of action of tDCS in pain treatment.

Which way is up? Asymmetric spectral input along the dorsal-ventral axis influences postural responses in an amphibious annelid.

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Jellies, John

2014-11-01

Medicinal leeches are predatory annelids that exhibit countershading and reside in aquatic environments where light levels might be variable. They also leave the water and must contend with terrestrial environments. Yet, leeches generally maintain a dorsal upward position despite lacking statocysts. Leeches respond visually to both green and near-ultraviolet (UV) light. I used LEDs to test the hypothesis that ventral, but not dorsal UV would evoke compensatory movements to orient the body. Untethered leeches were tested using LEDs emitting at red (632 nm), green (513 nm), blue (455 nm) and UV (372 nm). UV light evoked responses in 100 % of trials and the leeches often rotated the ventral surface away from it. Visible light evoked no or modest responses (12-15 % of trials) and no body rotation. Electrophysiological recordings showed that ventral sensilla responded best to UV, dorsal sensilla to green. Additionally, a higher order interneuron that is engaged in a variety of parallel networks responded vigorously to UV presented ventrally, and both the visible and UV responses exhibited pronounced light adaptation. These results strongly support the suggestion that a dorsal light reflex in the leech uses spectral comparisons across the dorsal-ventral axis rather than, or in addition to, luminance.

Percutaneous dorsal closing wedge osteotomy of the metatarsal neck in management of metatarsalgia.

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Lui, Tun Hing

2014-12-01

Metatarsalgia can be caused by plantarflexion of a central metatarsal or discrepancies in the metatarsals' length. Nonsurgical management is usually sufficient to achieve satisfactory results. For those recalcitrant cases, metatarsal osteotomy is needed to relieve the pain. We describe a technique of percutaneous dorsal closing wedge osteotomy of the metatarsal to manage the recalcitrant metatarsalgia. A case series was reviewed retrospectively. From March 2010 to March 2013, percutaneous dorsal closing wedge osteotomy of the metatarsal neck has been performed in 33 patients. Thirty six feet with 63 metatarsals were operated on. Thirty two second metatarsals, 22 third metatarsals, 5 fourth metatarsals and 4 fifth metatarsals were operated on. All the osteotomy sites healed up without any transverse plane deformity. The painful callosities subsided except in one operated metatarsal. Recurrence of painful callosities occurred in 2 operated metatarsals. Transfer metatarsalgia occurred in 2 feet. Floating toe deformity occurred in 2 operated rays. There was no nerve injury noted. Two patients had delayed wound healing with serous discharge and the wounds were eventually healed up with wound dressing. Percutaneous dorsal closing wedge osteotomy of the metatarsal neck is an effective and safe surgical treatment of recalcitrant metatarsalgia. Copyright © 2014 Elsevier Ltd. All rights reserved.

Defective functional connectivity between posterior hypothalamus and regions of the diencephalic-mesencephalic junction in chronic cluster headache.

Science.gov (United States)

Ferraro, Stefania; Nigri, Anna; Bruzzone, Maria Grazia; Brivio, Luca; Proietti Cecchini, Alberto; Verri, Mattia; Chiapparini, Luisa; Leone, Massimo

2018-01-01

Objective We tested the hypothesis of a defective functional connectivity between the posterior hypothalamus and diencephalic-mesencephalic regions in chronic cluster headache based on: a) clinical and neuro-endocrinological findings in cluster headache patients; b) neuroimaging findings during cluster headache attacks; c) neuroimaging findings in drug-refractory chronic cluster headache patients improved after successful deep brain stimulation. Methods Resting state functional magnetic resonance imaging, associated with a seed-based approach, was employed to investigate the functional connectivity of the posterior hypothalamus in chronic cluster headache patients (n = 17) compared to age and sex-matched healthy subjects (n = 16). Random-effect analyses were performed to study differences between patients and controls in ipsilateral and contralateral-to-the-pain posterior hypothalamus functional connectivity. Results Cluster headache patients showed an increased functional connectivity between the ipsilateral posterior hypothalamus and a number of diencephalic-mesencephalic structures, comprising ventral tegmental area, dorsal nuclei of raphe, and bilateral substantia nigra, sub-thalamic nucleus, and red nucleus ( p cluster headache patients mainly involves structures that are part of (i.e. ventral tegmental area, substantia nigra) or modulate (dorsal nuclei of raphe, sub-thalamic nucleus) the midbrain dopaminergic systems. The midbrain dopaminergic systems could play a role in cluster headache pathophysiology and in particular in the chronicization process. Future studies are needed to better clarify if this finding is specific to cluster headache or if it represents an unspecific response to chronic pain.

Spatially dynamic recurrent information flow across long-range dorsal motor network encodes selective motor goals.

Science.gov (United States)

Yoo, Peter E; Hagan, Maureen A; John, Sam E; Opie, Nicholas L; Ordidge, Roger J; O'Brien, Terence J; Oxley, Thomas J; Moffat, Bradford A; Wong, Yan T

2018-03-08

Performing voluntary movements involves many regions of the brain, but it is unknown how they work together to plan and execute specific movements. We recorded high-resolution ultra-high-field blood-oxygen-level-dependent signal during a cued ankle-dorsiflexion task. The spatiotemporal dynamics and the patterns of task-relevant information flow across the dorsal motor network were investigated. We show that task-relevant information appears and decays earlier in the higher order areas of the dorsal motor network then in the primary motor cortex. Furthermore, the results show that task-relevant information is encoded in general initially, and then selective goals are subsequently encoded in specifics subregions across the network. Importantly, the patterns of recurrent information flow across the network vary across different subregions depending on the goal. Recurrent information flow was observed across all higher order areas of the dorsal motor network in the subregions encoding for the current goal. In contrast, only the top-down information flow from the supplementary motor cortex to the frontoparietal regions, with weakened recurrent information flow between the frontoparietal regions and bottom-up information flow from the frontoparietal regions to the supplementary cortex were observed in the subregions encoding for the opposing goal. We conclude that selective motor goal encoding and execution rely on goal-dependent differences in subregional recurrent information flow patterns across the long-range dorsal motor network areas that exhibit graded functional specialization. © 2018 Wiley Periodicals, Inc.

Differences between Dorsal and Ventral Striatum in the Sensitivity of Tonically Active Neurons to Rewarding Events

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Kevin Marche

2017-07-01

Full Text Available Within the striatum, cholinergic interneurons, electrophysiologically identified as tonically active neurons (TANs, represent a relatively homogeneous group in terms of their functional properties. They display typical pause in tonic firing in response to rewarding events which are of crucial importance for reinforcement learning. These responses are uniformly distributed throughout the dorsal striatum (i.e., motor and associative striatum, but it is unknown, at least in monkeys, whether differences in the modulation of TAN activity exist in the ventral striatum (i.e., limbic striatum, a region specialized for processing of motivational information. To address this issue, we examined the activity of dorsal and ventral TANs in two monkeys trained on a Pavlovian conditioning task in which a visual stimulus preceded the delivery of liquid reward by a fixed time interval. We found that the proportion of TANs responding to the stimulus predictive of reward did not vary significantly across regions (58%–80%, whereas the fraction of TANs responding to reward was higher in the limbic striatum (100% compared to the motor (65% and associative striatum (52%. By examining TAN modulation at the level of both the population and the individual neurons, we showed that the duration of pause responses to the stimulus and reward was longer in the ventral than in the dorsal striatal regions. Also, the magnitude of the pause was greater in ventral than dorsal striatum for the stimulus predictive of reward but not for the reward itself. We found similar region-specific differences in pause response duration to the stimulus when the timing of reward was less predictable (fixed replaced by variable time interval. Regional variations in the duration and magnitude of the pause response were transferred from the stimulus to reward when reward was delivered in the absence of any predictive stimulus. It therefore appears that ventral TANs exhibit stronger responses to

Wnt5a regulates midbrain dopaminergic axon growth and guidance.

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Brette D Blakely

2011-03-01

Full Text Available During development, precise temporal and spatial gradients are responsible for guiding axons to their appropriate targets. Within the developing ventral midbrain (VM the cues that guide dopaminergic (DA axons to their forebrain targets remain to be fully elucidated. Wnts are morphogens that have been identified as axon guidance molecules. Several Wnts are expressed in the VM where they regulate the birth of DA neurons. Here, we describe that a precise temporo-spatial expression of Wnt5a accompanies the development of nigrostriatal projections by VM DA neurons. In mice at E11.5, Wnt5a is expressed in the VM where it was found to promote DA neurite and axonal growth in VM primary cultures. By E14.5, when DA axons are approaching their striatal target, Wnt5a causes DA neurite retraction in primary cultures. Co-culture of VM explants with Wnt5a-overexpressing cell aggregates revealed that Wnt5a is capable of repelling DA neurites. Antagonism experiments revealed that the effects of Wnt5a are mediated by the Frizzled receptors and by the small GTPase, Rac1 (a component of the non-canonical Wnt planar cell polarity pathway. Moreover, the effects were specific as they could be blocked by Wnt5a antibody, sFRPs and RYK-Fc. The importance of Wnt5a in DA axon morphogenesis was further verified in Wnt5a-/- mice, where fasciculation of the medial forebrain bundle (MFB as well as the density of DA neurites in the MFB and striatal terminals were disrupted. Thus, our results identify a novel role of Wnt5a in DA axon growth and guidance.

Dynamic representation of 3D auditory space in the midbrain of the free-flying echolocating bat

Science.gov (United States)

2018-01-01

Essential to spatial orientation in the natural environment is a dynamic representation of direction and distance to objects. Despite the importance of 3D spatial localization to parse objects in the environment and to guide movement, most neurophysiological investigations of sensory mapping have been limited to studies of restrained subjects, tested with 2D, artificial stimuli. Here, we show for the first time that sensory neurons in the midbrain superior colliculus (SC) of the free-flying echolocating bat encode 3D egocentric space, and that the bat’s inspection of objects in the physical environment sharpens tuning of single neurons, and shifts peak responses to represent closer distances. These findings emerged from wireless neural recordings in free-flying bats, in combination with an echo model that computes the animal’s instantaneous stimulus space. Our research reveals dynamic 3D space coding in a freely moving mammal engaged in a real-world navigation task. PMID:29633711

Drosophila heart cell movement to the midline occurs through both cell autonomous migration and dorsal closure.

Science.gov (United States)

Haack, Timm; Schneider, Matthias; Schwendele, Bernd; Renault, Andrew D

2014-12-15

The Drosophila heart is a linear organ formed by the movement of bilaterally specified progenitor cells to the midline and adherence of contralateral heart cells. This movement occurs through the attachment of heart cells to the overlying ectoderm which is undergoing dorsal closure. Therefore heart cells are thought to move to the midline passively. Through live imaging experiments and analysis of mutants that affect the speed of dorsal closure we show that heart cells in Drosophila are autonomously migratory and part of their movement to the midline is independent of the ectoderm. This means that heart formation in flies is more similar to that in vertebrates than previously thought. We also show that defects in dorsal closure can result in failure of the amnioserosa to properly degenerate, which can physically hinder joining of contralateral heart cells leading to a broken heart phenotype. Copyright © 2014 Elsevier Inc. All rights reserved.

Usefulness of Cross-Linked Human Acellular Dermal Matrix as an Implant for Dorsal Augmentation in Rhinoplasty.

Science.gov (United States)

Yang, Chae Eun; Kim, Soo Jung; Kim, Ji Hee; Lee, Ju Hee; Roh, Tai Suk; Lee, Won Jai

2018-02-01

Asian noses are relatively small and flat compared to Caucasians; therefore, rhinoplasty procedures often focus on dorsal augmentation and tip projection rather than reduction in the nasal framework. Various autologous and alloplastic implant materials have been used for dorsal augmentation. Recently, human acellular dermal matrices have been introduced as an implant material for dorsal augmentation, camouflaging autologous implants without an additional donor site. Here, we introduce a cross-linked human acellular dermal matrix as an implant material in augmentation rhinoplasty and share the clinical experiences. Eighteen patients who underwent augmentation rhinoplasty using acellular dermal matrix from April 2014 to November 2015 were reviewed retrospectively. Clinical outcomes and complications were assessed at the outpatient clinic during the follow-up period ranging from 8 to 38 months. Contour changes were assessed through comparison of preoperative and postoperative photographs by two independent plastic surgeons. Patient satisfaction was assessed at the outpatient clinic by six questions regarding aesthetic and functional aspects. Postoperative photographs demonstrated the height of the nasal dorsum did not decrease over time except two patients whose ADM was grafted into a subperiosteal pocket. Others who underwent supraperiosteal implantation showed acceptable maintenance of dorsal height. No major complication was reported. Overall, patient satisfaction scored 81.02 out of 100. Cross-linked human ADM has advantages of both autogenous and alloplastic materials. The surgical results remain stable without complications. Therefore, it is a suitable alternative implant material for dorsal augmentation in rhinoplasty. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

GABAergic Neurons of the Rat Dorsal Hippocampus Express Muscarinic Acetylcholine Receptors

NARCIS (Netherlands)

van der Zee, E.A.; Luiten, P.G.M.

1993-01-01

The expression of muscarinic acetylcholine receptors (mAChRs) in glutamic acid decarboxylase (GAD)-positive cells in the different strata of CA1, CA3, and the dentate gyrus (DG) of the dorsal hippocampus is examined by way of quantitative immunofluorescent double labeling employing M35, the

Selective dorsal rhizotomy opportunities with foot deformitiesin children with cerebral palsy

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Vladimir Markovich Kenis

2015-03-01

Full Text Available Foot deformities are the most common orthopedic condition in children with cerebral palsy. The aim of the study was to evaluate the influence of selective dorsal rhizotomy (SDR on foot deformities in children with cerebral palsy. The results were assessed clinically by measurement of changes in muscle spaticity and foot posture. Percentage of resection of dorsal rootlets was from 40 to 90 % of total thickness. The degree of tone reduction had a tendency to be more pronounced in the more proximal muscles and was minimal in calf muscles. Nevertheless, foot posture improved more significantly. That can be explained by generalimprovement of pathological posture at the level of more proximal joints. Thus, SDR has insignificant direct effect on spastic foot deformity and can not be recommended as a basic method of treatment even in pure spasticity. However, SDR should be considered as a part of multidisciplinary management protocol if foot deformity reflects more complex postural disturbance due to generalized spasticity.

Outcomes of Open Dorsal Wrist Ganglion Excision in Active-Duty Military Personnel.

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Balazs, George C; Donohue, Michael A; Drake, Matthew L; Ipsen, Derek; Nanos, George P; Tintle, Scott M

2015-09-01

To examine the most common presenting complaints of active-duty service members with isolated dorsal wrist ganglions and to determine the rate of return to unrestricted duty after open excision. Surgical records at 2 military facilities were screened to identify male and female active duty service members undergoing isolated open excision of dorsal wrist ganglions from January 1, 2006 to January 1, 2014. Electronic medical records and service disability databases were searched to identify the most common presenting symptoms and to determine whether patients returned to unrestricted active duty after surgery. Postoperative outcomes examined were pain persisting greater than 4 weeks after surgery, stiffness requiring formal occupational therapy treatment, surgical wound complications, and recurrence. A total of 125 active duty military personnel (Army, 54; Navy, 43; and Marine Corps, 28) met criteria for inclusion. Mean follow-up was 45 months. Fifteen percent (8 of 54) of the Army personnel were given permanent waivers from performing push-ups owing to persistent pain and stiffness. Pain persisting greater than 4 weeks after surgery was an independent predictor of eventual need for a permanent push-up waiver. The overall recurrence incidence was 9%. No demographic or perioperative factors were associated with recurrence. Patients whose occupation or activities require forceful wrist extension should be counseled on the considerable risk of residual pain and functional limitations that may occur after open dorsal wrist ganglion excision. Therapeutic IV. Published by Elsevier Inc.

A new early brachyuran (Crustacea, Decapoda) from the Middle Jurassic of northwest France, epibionts and ecological considerations

NARCIS (Netherlands)

Robin, N.; Bakel, van B.W.M.; Hondt, d' J.-L.; Charbonnier, S.

2015-01-01

The earliest known crabs are of Early and Middle Jurassic age; in general, they are rare. Here we describe a new species of homolodromioid from the late Bathonian of Sarthe (France), based on a single dorsal carapace, Tanidromites raboeufi n. sp. This specimen has mostly well-preserved cuticle, and

Postsynaptic dorsal column neurons express NK1 receptors following colon inflammation

Czech Academy of Sciences Publication Activity Database

Paleček, Jiří; Palečková, V.; Willis, W. D.

2003-01-01

Roč. 116, č. 2 (2003), s. 565-572 ISSN 0306-4522 Grant - others:NIH(US) NS09743; NIH(US) NS11255 Institutional research plan: CEZ:AV0Z5011922 Keywords : visceral pain * substance P * postsynaptic dorsal column Subject RIV: FH - Neurology Impact factor: 3.601, year: 2003

Reward Processing by the Dorsal Raphe Nucleus: 5-HT and Beyond

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Luo, Minmin; Zhou, Jingfeng; Liu, Zhixiang

2015-01-01

The dorsal raphe nucleus (DRN) represents one of the most sensitive reward sites in the brain. However, the exact relationship between DRN neuronal activity and reward signaling has been elusive. In this review, we will summarize anatomical, pharmacological, optogenetics, and electrophysiological studies on the functions and circuit mechanisms of…

THE USE OF SPONGOSTAN-WRAPPED DICED CARTILAGE GRAFT FOR OBTANINING A REGULAR DORSAL CONTOUR IN RHINOPLASTY: A PRELIMINARY REPORT

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Umut Tuncel

2013-03-01

Conclusion: As a result, we can say that spongostan wrapped diced cartilages graft seems to be a cheap, safe and effective method for obtaining a nice nasal dorsal contouring as well as for correcting and preventing of dorsal irregularities in rhinoplasty. [J Contemp Med 2013; 3(1.000: 12-16

Inhibitory coupling between inhibitory interneurons in the spinal cord dorsal horn

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Ribeiro-da-Silva Alfredo

2009-05-01

Full Text Available Abstract Local inhibitory interneurons in the dorsal horn play an important role in the control of excitability at the segmental level and thus determine how nociceptive information is relayed to higher structures. Regulation of inhibitory interneuron activity may therefore have critical consequences on pain perception. Indeed, disinhibition of dorsal horn neuronal networks disrupts the balance between excitation and inhibition and is believed to be a key mechanism underlying different forms of pain hypersensitivity and chronic pain states. In this context, studying the source and the synaptic properties of the inhibitory inputs that the inhibitory interneurons receive is important in order to predict the impact of drug action at the network level. To address this, we studied inhibitory synaptic transmission in lamina II inhibitory interneurons identified under visual guidance in spinal slices taken from transgenic mice expressing enhanced green fluorescent protein (EGFP under the control of the GAD promoter. The majority of these cells fired tonically to a long depolarizing current pulse. Monosynaptically evoked inhibitory postsynaptic currents (eIPSCs in these cells were mediated by both GABAA and glycine receptors. Consistent with this, both GABAA and glycine receptor-mediated miniature IPSCs were recorded in all of the cells. These inhibitory inputs originated at least in part from local lamina II interneurons as verified by simultaneous recordings from pairs of EGFP+ cells. These synapses appeared to have low release probability and displayed potentiation and asynchronous release upon repeated activation. In summary, we report on a previously unexamined component of the dorsal horn circuitry that likely constitutes an essential element of the fine tuning of nociception.

Highly efficient methods to obtain homogeneous dorsal neural progenitor cells from human and mouse embryonic stem cells and induced pluripotent stem cells.

Science.gov (United States)

Zhang, Meixiang; Ngo, Justine; Pirozzi, Filomena; Sun, Ying-Pu; Wynshaw-Boris, Anthony

2018-03-15

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have been widely used to generate cellular models harboring specific disease-related genotypes. Of particular importance are ESC and iPSC applications capable of producing dorsal telencephalic neural progenitor cells (NPCs) that are representative of the cerebral cortex and overcome the challenges of maintaining a homogeneous population of cortical progenitors over several passages in vitro. While previous studies were able to derive NPCs from pluripotent cell types, the fraction of dorsal NPCs in this population is small and decreases over several passages. Here, we present three protocols that are highly efficient in differentiating mouse and human ESCs, as well as human iPSCs, into a homogeneous and stable population of dorsal NPCs. These protocols will be useful for modeling cerebral cortical neurological and neurodegenerative disorders in both mouse and human as well as for high-throughput drug screening for therapeutic development. We optimized three different strategies for generating dorsal telencephalic NPCs from mouse and human pluripotent cell types through single or double inhibition of bone morphogenetic protein (BMP) and/or SMAD pathways. Mouse and human pluripotent cells were aggregated to form embryoid bodies in suspension and were treated with dorsomorphin alone (BMP inhibition) or combined with SB431542 (double BMP/SMAD inhibition) during neural induction. Neural rosettes were then selected from plated embryoid bodies to purify the population of dorsal NPCs. We tested the expression of key dorsal NPC markers as well as nonectodermal markers to confirm the efficiency of our three methods in comparison to published and commercial protocols. Single and double inhibition of BMP and/or SMAD during neural induction led to the efficient differentiation of dorsal NPCs, based on the high percentage of PAX6-positive cells and the NPC gene expression profile. There were no statistically

Differential effects of methylmercury on the synthesis of protein species in dorsal root ganglia of the rat

International Nuclear Information System (INIS)

Kasama, Hidetaka; Itoh, Kazuo; Omata, Saburo; Sugano, Hiroshi

1989-01-01

Dorsal root ganglia from control and methylmercury(MeHg)-treated rats were incubated in vitro with 35 S-methionine and the proteins synthesized were analyzed by two-dimensional electrophoresis. The double labelling method, in which proteins of control dorsal root ganglia labelled in vitro with 3 H-leucine were added to each of the two samples as an internal standard, was used to minimize unavoidable errors arising from the resolving procedure itself. The results obtained showed that the effect of MeHg on the synthesis of proteins in dorsal root ganglia was not uniform for individual protein species in the latent period of MeHg intoxication. Among 200 protein species investigated, 157 showed inhibition of synthesis close to that of the total proteins in the tissue (68% of the control). Among the remaining protein species, 20 showed real stimulation of synthesis, whereas 7 were moderately inhibited and 16 were inhibited more strongly than the total proteins in the tissue. These results suggest that the effect of MeHg on the synthetic rates for protein species in dorsal root ganglia differs with the species, and that unusual elevation or reduction of the synthesis of some protein species caused by MeHg may lead to impairment of normal nerve functions. (orig.)

Simultaneous Dorsal Dislocation of the Proximal and Distal Interphalangeal Joints in the Middle Finger: A Case Report

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Mohamed Ali Sbai

2017-07-01

Full Text Available Introduction Dorsal dislocation of a proximal or distal interphalangeal joint is a common clinical problem. However, simultaneous dislocation of both joints in the same digit is rare. Case Presentation A 32-year-old male injured his left hand third finger while biking. Examination revealed a stepladder deformity. Neurovascular examination was normal. Radiographs revealed dorsal dislocation of both the proximal and distal interphalangeal joints. The finger was reduced easily by longitudinal manual traction under the digital block. The finger was splinted in the intrinsic plus position for 3 weeks accompanied with active range of motion. After 6 months, the patient returned to normal sporting activity without limitation of motion. Conclusions In case of simultaneous dorsal dislocation of a proximal and distal interphalangeal joint, closed reduction is the treatment of choice and it could result in good and normal range of motion.

Activin A Inhibits MPTP and LPS-Induced Increases in Inflammatory Cell Populations and Loss of Dopamine Neurons in the Mouse Midbrain In Vivo.

Science.gov (United States)

Stayte, Sandy; Rentsch, Peggy; Tröscher, Anna R; Bamberger, Maximilian; Li, Kong M; Vissel, Bryce

2017-01-01

Parkinson's disease is a chronic neurodegenerative disease characterized by a significant loss of dopaminergic neurons within the substantia nigra pars compacta region and a subsequent loss of dopamine within the striatum. A promising avenue of research has been the administration of growth factors to promote the survival of remaining midbrain neurons, although the mechanism by which they provide neuroprotection is not understood. Activin A, a member of the transforming growth factor β superfamily, has been shown to be a potent anti-inflammatory following acute brain injury and has been demonstrated to play a role in the neuroprotection of midbrain neurons against MPP+-induced degeneration in vitro. We hypothesized that activin A may offer similar anti-inflammatory and neuroprotective effects in in vivo mouse models of Parkinson's disease. We found that activin A significantly attenuated the inflammatory response induced by both MPTP and intranigral administration of lipopolysaccharide in C57BL/6 mice. We found that administration of activin A promoted survival of dopaminergic and total neuron populations in the pars compacta region both 8 days and 8 weeks after MPTP-induced degeneration. Surprisingly, no corresponding protection of striatal dopamine levels was found. Furthermore, activin A failed to protect against loss of striatal dopamine transporter expression in the striatum, suggesting the neuroprotective action of activin A may be localized to the substantia nigra. Together, these results provide the first evidence that activin A exerts potent neuroprotection and anti-inflammatory effects in the MPTP and lipopolysaccharide mouse models of Parkinson's disease.

Conventional 3T brain MRI and diffusion tensor imaging in the diagnostic workup of early stage parkinsonism

International Nuclear Information System (INIS)

Meijer, Frederick J.A.; Rumund, Anouke van; Tuladhar, Anil M.; Aerts, Marjolein B.; Titulaer, Imke; Esselink, Rianne A.J.; Bloem, Bastiaan R.; Verbeek, Marcel M.; Goraj, Bozena

2015-01-01

The aim of this study is to evaluate whether the diagnostic accuracy of 3 T brain MRI is improved by region of interest (ROI) measures of diffusion tensor imaging (DTI), to differentiate between neurodegenerative atypical parkinsonism (AP) and Parkinson's disease (PD) in early stage parkinsonism. We performed a prospective observational cohort study of 60 patients presenting with early stage parkinsonism and initial uncertain diagnosis. At baseline, patients underwent a 3 T brain MRI including DTI. After clinical follow-up (mean 28.3 months), diagnoses could be made in 49 patients (30 PD and 19 AP). Conventional brain MRI was evaluated for regions of atrophy and signal intensity changes. Tract-based spatial statistics and ROI analyses of DTI were performed to analyze group differences in mean diffusivity (MD) and fractional anisotropy (FA), and diagnostic thresholds were determined. Diagnostic accuracy of conventional brain MRI and DTI was assessed with the receiver operating characteristic (ROC). Significantly higher MD of the centrum semiovale, body corpus callosum, putamen, external capsule, midbrain, superior cerebellum, and superior cerebellar peduncles was found in AP. Significantly increased MD of the putamen was found in multiple system atrophy-parkinsonian form (MSA-P) and increased MD in the midbrain and superior cerebellar peduncles in progressive supranuclear palsy (PSP). The diagnostic accuracy of brain MRI to identify AP as a group was not improved by ROI measures of MD, though the diagnostic accuracy to identify MSA-P was slightly increased (AUC 0.82 to 0.85). The diagnostic accuracy of brain MRI to identify AP as a group was not improved by the current analysis approach to DTI, though DTI measures could be of added value to identify AP subgroups. (orig.)

Conventional 3T brain MRI and diffusion tensor imaging in the diagnostic workup of early stage parkinsonism

Energy Technology Data Exchange (ETDEWEB)

Meijer, Frederick J.A. [Radboud University Nijmegen Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Rumund, Anouke van; Tuladhar, Anil M.; Aerts, Marjolein B.; Titulaer, Imke; Esselink, Rianne A.J.; Bloem, Bastiaan R. [Radboud University Nijmegen Medical Center, Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen (Netherlands); Verbeek, Marcel M. [Radboud University Nijmegen Medical Center, Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen (Netherlands); Radboud University Nijmegen Medical Center, Department of Laboratory Medicine, Nijmegen (Netherlands); Goraj, Bozena [Radboud University Nijmegen Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Medical Center of Postgraduate Education, Department of Diagnostic Imaging, Warsaw (Poland)

2015-07-15

The aim of this study is to evaluate whether the diagnostic accuracy of 3 T brain MRI is improved by region of interest (ROI) measures of diffusion tensor imaging (DTI), to differentiate between neurodegenerative atypical parkinsonism (AP) and Parkinson's disease (PD) in early stage parkinsonism. We performed a prospective observational cohort study of 60 patients presenting with early stage parkinsonism and initial uncertain diagnosis. At baseline, patients underwent a 3 T brain MRI including DTI. After clinical follow-up (mean 28.3 months), diagnoses could be made in 49 patients (30 PD and 19 AP). Conventional brain MRI was evaluated for regions of atrophy and signal intensity changes. Tract-based spatial statistics and ROI analyses of DTI were performed to analyze group differences in mean diffusivity (MD) and fractional anisotropy (FA), and diagnostic thresholds were determined. Diagnostic accuracy of conventional brain MRI and DTI was assessed with the receiver operating characteristic (ROC). Significantly higher MD of the centrum semiovale, body corpus callosum, putamen, external capsule, midbrain, superior cerebellum, and superior cerebellar peduncles was found in AP. Significantly increased MD of the putamen was found in multiple system atrophy-parkinsonian form (MSA-P) and increased MD in the midbrain and superior cerebellar peduncles in progressive supranuclear palsy (PSP). The diagnostic accuracy of brain MRI to identify AP as a group was not improved by ROI measures of MD, though the diagnostic accuracy to identify MSA-P was slightly increased (AUC 0.82 to 0.85). The diagnostic accuracy of brain MRI to identify AP as a group was not improved by the current analysis approach to DTI, though DTI measures could be of added value to identify AP subgroups. (orig.)

The analgesic effect of clonidine as an adjuvant in dorsal penile ...

African Journals Online (AJOL)

Introduction: Dorsal penile nerve block (DPNB) is a commonly performed regional anesthetic technique for male circumcision. The aim of this study was to assess the analgesic effect of the adjunction of clonidine to bupivacaine 0.5% in this block. Methods: It was a prospective randomized double-blind clinical trial including ...

Dorsal buccal mucosal graft urethroplasty by a ventral sagittal urethrotomy and minimal-access perineal approach for anterior urethral stricture.

Science.gov (United States)

Gupta, N P; Ansari, M S; Dogra, P N; Tandon, S

2004-06-01

To present the technique of dorsal buccal mucosal graft urethroplasty through a ventral sagittal urethrotomy and minimal access perineal approach for anterior urethral stricture. From July 2001 to December 2002, 12 patients with a long anterior urethral stricture had the anterior urethra reconstructed, using a one-stage urethroplasty with a dorsal onlay buccal mucosal graft through a ventral sagittal urethrotomy. The urethra was approached via a small perineal incision irrespective of the site and length of the stricture. The penis was everted through the perineal wound. No urethral dissection was used on laterally or dorsally, so as not to jeopardize the blood supply. The mean (range) length of the stricture was 5 (3-16) cm and the follow-up 12 (10-16) months. The results were good in 11 of the 12 patients. One patient developed a stricture at the proximal anastomotic site and required optical internal urethrotomy. Dorsal buccal mucosal graft urethroplasty via a minimal access perineal approach is a simple technique with a good surgical outcome; it does not require urethral dissection and mobilization and hence preserves the blood supply.

The first metatarsal web space: its applied anatomy and usage in tracing the first dorsal metatarsal artery in thumb reconstruction.

Science.gov (United States)

Xu, Yong-Qing; Li, Jun; Zhong, Shi-Zhen; Xu, Da-Chuan; Xu, Xiao-Shan; Guo, Yuan-Fa; Wang, Xin-Min; Li, Zhu-Yi; Zhu, Yue-Liang

2004-12-01

To clarify the anatomical relationship of the structures in the first toe webbing space for better dissection of toes in thumb reconstruction. The first dorsal metatarsal artery, the first deep transverse metatarsal ligament and the extensor expansion were observed on 42 adult cadaveric lower extremities. Clinically the method of tracing the first dorsal metatarsal artery around the space of the extensor expansion was used in 36 cases of thumb reconstruction. The distal segments of the first dorsal metatarsal artery of Gilbert types I and II were located superficially to the extensor expansion. The harvesting time of a toe was shortened from 90 minutes to 50 minutes with 100% survival of reconstructed fingers. The distal segment of the first dorsal metatarsal artery lies constantly at the superficial layer of the extensor expansion. Most of the first metatarsal arteries of Gilbert types I and II can be easily located via the combined sequential and reverse dissection around the space of the extensor expansion.

Synaptic plasticity and sensory-motor improvement following fibrin sealant dorsal root reimplantation and mononuclear cell therapy

Science.gov (United States)

Benitez, Suzana U.; Barbizan, Roberta; Spejo, Aline B.; Ferreira, Rui S.; Barraviera, Benedito; Góes, Alfredo M.; de Oliveira, Alexandre L. R.

2014-01-01

Root lesions may affect both dorsal and ventral roots. However, due to the possibility of generating further inflammation and neuropathic pain, surgical procedures do not prioritize the repair of the afferent component. The loss of such sensorial input directly disturbs the spinal circuits thus affecting the functionality of the injuried limb. The present study evaluated the motor and sensory improvement following dorsal root reimplantation with fibrin sealant (FS) plus bone marrow mononuclear cells (MC) after dorsal rhizotomy. MC were used to enhance the repair process. We also analyzed changes in the glial response and synaptic circuits within the spinal cord. Female Lewis rats (6–8 weeks old) were divided in three groups: rhizotomy (RZ group), rhizotomy repaired with FS (RZ+FS group) and rhizotomy repaired with FS and MC (RZ+FS+MC group). The behavioral tests electronic von-Frey and Walking track test were carried out. For immunohistochemistry we used markers to detect different synapse profiles as well as glial reaction. The behavioral results showed a significant decrease in sensory and motor function after lesion. The reimplantation decreased glial reaction and improved synaptic plasticity of afferent inputs. Cell therapy further enhanced the rewiring process. In addition, both reimplanted groups presented twice as much motor control compared to the non-treated group. In conclusion, the reimplantation with FS and MC is efficient and may be considered an approach to improve sensory-motor recovery following dorsal rhizotomy. PMID:25249946

Blindness alters the microstructure of the ventral but not the dorsal visual stream

DEFF Research Database (Denmark)

Reislev, Nina L; Kupers, Ron; Siebner, Hartwig R

2016-01-01

Visual deprivation from birth leads to reorganisation of the brain through cross-modal plasticity. Although there is a general agreement that the primary afferent visual pathways are altered in congenitally blind individuals, our knowledge about microstructural changes within the higher...... pathways in 12 congenitally blind, 15 late blind and 15 normal sighted controls. We also studied six prematurely born individuals with normal vision to control for the effects of prematurity on brain connectivity. Our data revealed a reduction in fractional anisotropy in the ventral but not the dorsal......-order visual streams, and how this is affected by onset of blindness, remains scant. We used diffusion tensor imaging and tractography to investigate microstructural features in the dorsal (superior longitudinal fasciculus) and ventral (inferior longitudinal and inferior fronto-occipital fasciculi) visual...

From genes to brain development to phenotypic behavior: "dorsal-stream vulnerability" in relation to spatial cognition, attention, and planning of actions in Williams syndrome (WS) and other developmental disorders.

Science.gov (United States)

Atkinson, Janette; Braddick, Oliver

2011-01-01

children with WS, but this test battery is too demanding for many children and adults with WS. Consequently, we have devised a new set of tests of attention, the Early Childhood Attention Battery (ECAB). This uses similar principles to the TEA-Ch, but adapted for mental ages younger than 6 years. The ECAB shows a distinctive attention profile for WS individuals relative to their overall cognitive development, with relative strength in tasks of sustained attention and poorer performance on tasks of selective attention and executive control. These profiles, and the characteristic developmental courses, also show differences between children with Down's syndrome and WS. This chapter briefly reviews new research findings on WS in these areas, relating the development of brain systems in WS to evidence from neuroimaging in typically developing infants, children born very preterm, and normal adults. The hypothesis of "dorsal-stream(s) vulnerability" which will be discussed includes a number of interlinked brain networks, subserving not only global visual processing and formulation of visuomotor actions but interlinked networks of attention. Copyright © 2011 Elsevier B.V. All rights reserved.

Relative Contributions of the Dorsal vs. Ventral Speech Streams to Speech Perception are Context Dependent: a lesion study

Directory of Open Access Journals (Sweden)

Corianne Rogalsky

2014-04-01

Full Text Available The neural basis of speech perception has been debated for over a century. While it is generally agreed that the superior temporal lobes are critical for the perceptual analysis of speech, a major current topic is whether the motor system contributes to speech perception, with several conflicting findings attested. In a dorsal-ventral speech stream framework (Hickok & Poeppel 2007, this debate is essentially about the roles of the dorsal versus ventral speech processing streams. A major roadblock in characterizing the neuroanatomy of speech perception is task-specific effects. For example, much of the evidence for dorsal stream involvement comes from syllable discrimination type tasks, which have been found to behaviorally doubly dissociate from auditory comprehension tasks (Baker et al. 1981. Discrimination task deficits could be a result of difficulty perceiving the sounds themselves, which is the typical assumption, or it could be a result of failures in temporary maintenance of the sensory traces, or the comparison and/or the decision process. Similar complications arise in perceiving sentences: the extent of inferior frontal (i.e. dorsal stream activation during listening to sentences increases as a function of increased task demands (Love et al. 2006. Another complication is the stimulus: much evidence for dorsal stream involvement uses speech samples lacking semantic context (CVs, non-words. The present study addresses these issues in a large-scale lesion-symptom mapping study. 158 patients with focal cerebral lesions from the Mutli-site Aphasia Research Consortium underwent a structural MRI or CT scan, as well as an extensive psycholinguistic battery. Voxel-based lesion symptom mapping was used to compare the neuroanatomy involved in the following speech perception tasks with varying phonological, semantic, and task loads: (i two discrimination tasks of syllables (non-words and words, respectively, (ii two auditory comprehension tasks

Neural correlates of consciousness: a definition of the dorsal and ventral streams and their relation to phenomenology.

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Vakalopoulos, Costa

2005-01-01

The paper presents a hypothesis for a neural correlate of consciousness. A proposal is made that both the dorsal and ventral streams must be concurrently active to generate conscious awareness and that V1 (striate cortex) provides a serial link between them. An argument is presented against a true extrastriate communication between the dorsal and ventral streams. Secondly, a detailed theory is developed for the structure of the visual hierarchy. Premotor theory states that each organism-object interaction can be described by the two quantitative measures of torque and change in joint position served by the basal ganglia and cerebellum, respectively. This leads to a component theory of motor efference copy providing a fundamental tool for categorizing dorsal and ventral stream networks. The rationale for this is that the dorsal stream specifies spatial coordinates of the external world, which can be coded by the reafference of changes in joint position. The ventral stream is concerned with object recognition and is coded for by forces exerted on the world during a developmental exploratory phase of the organism. The proposed pathways for a component motor efference copy from both the cerebellum and basal ganglia converge on the thalamus and modulate thalamocortical projections via the thalamic reticular nucleus. The origin of the corticopontine projections, which are a massive pathway for cortical information to reach the cerebellum, coincides with the area typically considered as part of the dorsal stream, whereas the entire cortex projects to the striatum. This adds empirical support for a new conceptualization of the visual streams. The model also presents a solution to the binding problem of a neural correlate of consciousness, that is, how a distributed neural network synchronizes its activity during a cognitive event. It represents a reinterpretation of the current status of the visual hierarchy.

HDAC I inhibition in the dorsal and ventral hippocampus differentially modulates predator-odor fear learning and generalization.

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Yuan, Robin K; Hebert, Jenna C; Thomas, Arthur S; Wann, Ellen G; Muzzio, Isabel A

2015-01-01

Although predator odors are ethologically relevant stimuli for rodents, the molecular pathways and contribution of some brain regions involved in predator odor conditioning remain elusive. Inhibition of histone deacetylases (HDACs) in the dorsal hippocampus has been shown to enhance shock-induced contextual fear learning, but it is unknown if HDACs have differential effects along the dorso-ventral hippocampal axis during predator odor fear learning. We injected MS-275, a class I HDAC inhibitor, bilaterally in the dorsal or ventral hippocampus of mice and found that it had no effects on innate anxiety in either region. We then assessed the effects of MS-275 at different stages of fear learning along the longitudinal hippocampal axis. Animals were injected with MS-275 or vehicle after context pre-exposure (pre-conditioning injections), when a representation of the context is first formed, or after exposure to coyote urine (post-conditioning injections), when the context becomes associated with predator odor. When MS-275 was administered after context pre-exposure, dorsally injected animals showed enhanced fear in the training context but were able to discriminate it from a neutral environment. Conversely, ventrally injected animals did not display enhanced learning in the training context but generalized the fear response to a neutral context. However, when MS-275 was administered after conditioning, there were no differences between the MS-275 and vehicle control groups in either the dorsal or ventral hippocampus. Surprisingly, all groups displayed generalization to a neutral context, suggesting that predator odor exposure followed by a mild stressor such as restraint leads to fear generalization. These results may elucidate distinct functions of the dorsal and ventral hippocampus in predator odor-induced fear conditioning as well as some of the molecular mechanisms underlying fear generalization.

LOCUS-COERULEUS PROJECTIONS TO THE DORSAL MOTOR VAGUS NUCLEUS IN THE RAT

NARCIS (Netherlands)

TERHORST, GJ; TOES, GJ; VANWILLIGEN, JD

1991-01-01

The origin of the noradrenergic innervation of the preganglionic autonomic nuclei in the medulla oblongata and spinal cord is still controversial. In this investigation descending connections of the locus coeruleus to the dorsal motor vagus nucleus in the rat are studied with Phaseolus vulgaris

OCD candidate gene SLC1A1/EAAT3 impacts basal ganglia-mediated activity and stereotypic behavior.

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Zike, Isaac D; Chohan, Muhammad O; Kopelman, Jared M; Krasnow, Emily N; Flicker, Daniel; Nautiyal, Katherine M; Bubser, Michael; Kellendonk, Christoph; Jones, Carrie K; Stanwood, Gregg; Tanaka, Kenji Fransis; Moore, Holly; Ahmari, Susanne E; Veenstra-VanderWeele, Jeremy

2017-05-30

Obsessive-compulsive disorder (OCD) is a chronic, disabling condition with inadequate treatment options that leave most patients with substantial residual symptoms. Structural, neurochemical, and behavioral findings point to a significant role for basal ganglia circuits and for the glutamate system in OCD. Genetic linkage and association studies in OCD point to SLC1A1 , which encodes the neuronal glutamate/aspartate/cysteine transporter excitatory amino acid transporter 3 (EAAT3)/excitatory amino acid transporter 1 (EAAC1). However, no previous studies have investigated EAAT3 in basal ganglia circuits or in relation to OCD-related behavior. Here, we report a model of Slc1a1 loss based on an excisable STOP cassette that yields successful ablation of EAAT3 expression and function. Using amphetamine as a probe, we found that EAAT3 loss prevents expected increases in ( i ) locomotor activity, ( ii ) stereotypy, and ( iii ) immediate early gene induction in the dorsal striatum following amphetamine administration. Further, Slc1a1 -STOP mice showed diminished grooming in an SKF-38393 challenge experiment, a pharmacologic model of OCD-like grooming behavior. This reduced grooming is accompanied by reduced dopamine D 1 receptor binding in the dorsal striatum of Slc1a1 -STOP mice. Slc1a1 -STOP mice also exhibit reduced extracellular dopamine concentrations in the dorsal striatum both at baseline and following amphetamine challenge. Viral-mediated restoration of Slc1a1 /EAAT3 expression in the midbrain but not in the striatum results in partial rescue of amphetamine-induced locomotion and stereotypy in Slc1a1 -STOP mice, consistent with an impact of EAAT3 loss on presynaptic dopaminergic function. Collectively, these findings indicate that the most consistently associated OCD candidate gene impacts basal ganglia-dependent repetitive behaviors.

Core cooling and thermal responses during whole-head, facial, and dorsal immersion in 17 degrees C water.

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Pretorius, Thea; Gagnon, Dominique D; Giesbrecht, Gordon G

2010-10-01

This study isolated the effects of dorsal, facial, and whole-head immersion in 17 degrees C water on peripheral vasoconstriction and the rate of body core cooling. Seven male subjects were studied in thermoneutral air (approximately 28 degrees C). On 3 separate days, they lay prone or supine on a bed with their heads inserted through the side of an adjustable immersion tank. Following 10 min of baseline measurements, the water level was raised such that the water immersed the dorsum, face, or whole head, with the immersion period lasting 60 min. During the first 30 min, the core (esophageal) cooling rate increased from dorsum (0.29 ± 0.2 degrees C h-1) to face (0.47 ± 0.1 degrees C h-1) to whole head (0.69 ± 0.2 degrees C h(-1)) (p whole-head immersion (114 ± 52% h(-1)) than in either facial (51 ± 47% h-1) or dorsal (41 ± 55% h(-1)) immersion (p whole-head (120.5 ± 13 kJ), facial (86.8 ± 17 kJ), and dorsal (46.0 ± 11 kJ) immersion (p whole head elicited a higher rate of vasoconstriction, the face did not elicit more vasoconstriction than the dorsum. Rather, the progressive increase in core cooling from dorsal to facial to whole-head immersion simply correlates with increased heat loss.

Increased functional connectivity in the ventral and dorsal streams during retrieval of novel words in professional musicians.

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Dittinger, Eva; Valizadeh, Seyed Abolfazl; Jäncke, Lutz; Besson, Mireille; Elmer, Stefan

2018-02-01

Current models of speech and language processing postulate the involvement of two parallel processing streams (the dual stream model): a ventral stream involved in mapping sensory and phonological representations onto lexical and conceptual representations and a dorsal stream contributing to sound-to-motor mapping, articulation, and to how verbal information is encoded and manipulated in memory. Based on previous evidence showing that music training has an influence on language processing, cognitive functions, and word learning, we examined EEG-based intracranial functional connectivity in the ventral and dorsal streams while musicians and nonmusicians learned the meaning of novel words through picture-word associations. In accordance with the dual stream model, word learning was generally associated with increased beta functional connectivity in the ventral stream compared to the dorsal stream. In addition, in the linguistically most demanding "semantic task," musicians outperformed nonmusicians, and this behavioral advantage was accompanied by increased left-hemispheric theta connectivity in both streams. Moreover, theta coherence in the left dorsal pathway was positively correlated with the number of years of music training. These results provide evidence for a complex interplay within a network of brain regions involved in semantic processing and verbal memory functions, and suggest that intensive music training can modify its functional architecture leading to advantages in novel word learning. © 2017 Wiley Periodicals, Inc.

Multiple Causal Links Between Magnocellular-Dorsal Pathway Deficit and Developmental Dyslexia.

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Gori, Simone; Seitz, Aaron R; Ronconi, Luca; Franceschini, Sandro; Facoetti, Andrea

2016-10-17

Although impaired auditory-phonological processing is the most popular explanation of developmental dyslexia (DD), the literature shows that the combination of several causes rather than a single factor contributes to DD. Functioning of the visual magnocellular-dorsal (MD) pathway, which plays a key role in motion perception, is a much debated, but heavily suspected factor contributing to DD. Here, we employ a comprehensive approach that incorporates all the accepted methods required to test the relationship between the MD pathway dysfunction and DD. The results of 4 experiments show that (1) Motion perception is impaired in children with dyslexia in comparison both with age-match and with reading-level controls; (2) pre-reading visual motion perception-independently from auditory-phonological skill-predicts future reading development, and (3) targeted MD trainings-not involving any auditory-phonological stimulation-leads to improved reading skill in children and adults with DD. Our findings demonstrate, for the first time, a causal relationship between MD deficits and DD, virtually closing a 30-year long debate. Since MD dysfunction can be diagnosed much earlier than reading and language disorders, our findings pave the way for low resource-intensive, early prevention programs that could drastically reduce the incidence of DD. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

pix-1 controls early elongation in parallel with mel-11 and let-502 in Caenorhabditis elegans.

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Martin, Emmanuel; Harel, Sharon; Nkengfac, Bernard; Hamiche, Karim; Neault, Mathieu; Jenna, Sarah

2014-01-01

Cell shape changes are crucial for metazoan development. During Caenorhabditis elegans embryogenesis, epidermal cell shape changes transform ovoid embryos into vermiform larvae. This process is divided into two phases: early and late elongation. Early elongation involves the contraction of filamentous actin bundles by phosphorylated non-muscle myosin in a subset of epidermal (hypodermal) cells. The genes controlling early elongation are associated with two parallel pathways. The first one involves the rho-1/RHOA-specific effector let-502/Rho-kinase and mel-11/myosin phosphatase regulatory subunit. The second pathway involves the CDC42/RAC-specific effector pak-1. Late elongation is driven by mechanotransduction in ventral and dorsal hypodermal cells in response to body-wall muscle contractions, and involves the CDC42/RAC-specific Guanine-nucleotide Exchange Factor (GEF) pix-1, the GTPase ced-10/RAC and pak-1. In this study, pix-1 is shown to control early elongation in parallel with let-502/mel-11, as previously shown for pak-1. We show that pix-1, pak-1 and let-502 control the rate of elongation, and the antero-posterior morphology of the embryos. In particular, pix-1 and pak-1 are shown to control head, but not tail width, while let-502 controls both head and tail width. This suggests that let-502 function is required throughout the antero-posterior axis of the embryo during early elongation, while pix-1/pak-1 function may be mostly required in the anterior part of the embryo. Supporting this hypothesis we show that low pix-1 expression level in the dorsal-posterior hypodermal cells is required to ensure high elongation rate during early elongation.

Spatially Compact Neural Clusters in the Dorsal Striatum Encode Locomotion Relevant Information.

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Barbera, Giovanni; Liang, Bo; Zhang, Lifeng; Gerfen, Charles R; Culurciello, Eugenio; Chen, Rong; Li, Yun; Lin, Da-Ting

2016-10-05

An influential striatal model postulates that neural activities in the striatal direct and indirect pathways promote and inhibit movement, respectively. Normal behavior requires coordinated activity in the direct pathway to facilitate intended locomotion and indirect pathway to inhibit unwanted locomotion. In this striatal model, neuronal population activity is assumed to encode locomotion relevant information. Here, we propose a novel encoding mechanism for the dorsal striatum. We identified spatially compact neural clusters in both the direct and indirect pathways. Detailed characterization revealed similar cluster organization between the direct and indirect pathways, and cluster activities from both pathways were correlated with mouse locomotion velocities. Using machine-learning algorithms, cluster activities could be used to decode locomotion relevant behavioral states and locomotion velocity. We propose that neural clusters in the dorsal striatum encode locomotion relevant information and that coordinated activities of direct and indirect pathway neural clusters are required for normal striatal controlled behavior. VIDEO ABSTRACT. Published by Elsevier Inc.

Crucial roles of NGF in dorsal horn plasticity in partially deafferentated cats.

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Liu, Jia; Chen, Shan-Shan; Dan, Qi-Qin; Rong, Rong; Zhou, Xue; Zhang, Lian-Feng; Wang, Ting-Hua

2011-04-01

Though exogenous nerve growth factor (NGF) has been implicated in spinal cord plasticity, whether endogenous NGF plays a crucial role has not been established in vivo. This study investigated first the role of endogenous NGF in spinal dorsal horn (DH) plasticity following removal of L1-L5 and L7-S2 dorsal root ganglions (DRGs) in cats. Co-culture of chick embryo DRG with DH condition media, protein band fishing by cells as well as western blot showed that NGF could promote neurite growth in vitro. Immunohistochemistry and in situ hybridization technique revealed an increase in the NGF and NGF mRNA immunoreactive cells in the DH after partial deafferentation. Lastly, after blocking with NGF antibody, choleragen subunit B horseradish peroxidase (CB-HRP) tracing showed a reduction in the neuronal sprouting observed in the DH. Our results demonstrated that in the cat, endogenous NGF plays a crucial role in DH plasticity after partial deafferentation.

Anatomical variations in dorsal metatarsal arteries with surgical significance: A cadaveric study

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Preeti Shivshankar Awari

2017-01-01

Full Text Available Introduction: Based on angiosome concept to revascularize a particular artery, the microvascular and reconstructive surgeons must know the anatomy and variations in the arteries in that specific region of the body to achieve better results. Nowadays, dorsal metatarsal artery (DMTA perforator flaps and toe grafts are becoming popular which also demand adequate information about normal anatomy and variants in these arteries for fruitful results. Materials and Methods: The authors studied normal anatomy and variations in the origin of DMTAs in 50 lower extremities of 25 embalmed cadavers. Results: The authors found many variations as the absence of DMTAs, origin of the DMTA from the deep plantar arch. The places wherever the arcuate artery was absent the lateral tarsal artery gave rise to dorsal metatarsal arteries. Conclusion: Being familiar with the incidence of anatomical variations in the origin of the DMTAs can increase vigilance in vascular and reconstructive surgeries leading to better prognosis. surgeries leading to better prognosis.

p38 MAPK as an essential regulator of dorsal-ventral axis specification and skeletogenesis during sea urchin development: a re-evaluation.

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Molina, Maria Dolores; Quirin, Magali; Haillot, Emmanuel; Jimenez, Felipe; Chessel, Aline; Lepage, Thierry

2017-06-15

Dorsal-ventral axis formation in the sea urchin embryo relies on the asymmetrical expression of the TGFβ Nodal. The p38-MAPK pathway has been proposed to be essential for dorsal-ventral axis formation by acting upstream of nodal expression. Here, we report that, in contrast to previous studies that used pharmacological inhibitors of p38, manipulating the activity of p38 by genetic means has no obvious impact on morphogenesis. Instead, we discovered that p38 inhibitors strongly disrupt specification of all germ layers by blocking signalling from the Nodal receptor and by interfering with the ERK pathway. Strikingly, while expression of a mutant p38 that is resistant to SB203580 did not rescue dorsal-ventral axis formation or skeletogenesis in embryos treated with this inhibitor, expression of mutant Nodal receptors that are resistant to SB203580 fully restored nodal expression in SB203580-treated embryos. Taken together, these results establish that p38 activity is not required for dorsal-ventral axis formation through nodal expression nor for skeletogenesis. Our results prompt a re-evaluation of the conclusions of several recent studies that linked p38 activity to dorsal-ventral axis formation and to patterning of the skeleton. © 2017. Published by The Company of Biologists Ltd.

Histopathological evaluation of urethroplasty with dorsal buccal mucosa: an experimental study in rabbits

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Geovanne F. Souza

2008-06-01

Full Text Available PURPOSE: Buccal mucosa is a widely accepted tissue for urethroplasty. The exact healing and tissue integration process, mainly the histological characteristics of dorsal buccal mucosa graft urethroplasty when used dorsally to reconstruct the urethral plate has not previously been assessed, and thus we developed an experimental model to address this question. MATERIALS AND METHODS: In 12 New Zealand rabbits (weight 2.5 kg we surgically created a dorsal penile urethral defect. A buccal mucosa graft was sutured to the corpora and tunica albuginea, and the ventral urethra anastomosed to this new urethral plate. The animals were divided in three groups and sacrificed 1, 3 and 6 weeks after surgery (groups 1, 2 and 3. A retrograde urethrogram was obtained at autopsy in the last group and the penis analyzed histologically with hematoxylin-eosin and Masson's staining. RESULTS: The urethrograms showed no evidence of fistula or stricture. In group 1 the histopathological analysis showed submucosal lymph-mononuclear inflammatory edema, numerous eosinophils and squamous epithelium integrated into the adjacent urothelium. In group 2 there was no evidence of an inflammatory response but rather complete subepithelial hyaline healing, which was more marked in group 3. CONCLUSION: Healing of buccal mucosa grafts to reconstruct the urethral plate can be achieved by total integration of the squamous epithelium with the urothelium, maintaining the original histological properties of the graft with no fibrosis or retraction.

CONSEQÜÊNCIAS DA LAMINECTOMIA DORSAL DO TIPO FUNKQUIST A EM CÃES NORMAIS CONSEQUENCES OF THE FUNKQUIST A DORSAL LAMINECTOMY, IN NORMAL DOGS

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Eduardo Alberto Tudury

2001-02-01

Full Text Available O objetivo desta pesquisa foi verificar os efeitos da laminectomia dorsal do tipo Funkquist A em cães normais. A técnica realizada consistiu em abordagem dorsal à coluna vertebral; remoção (com ou sem a ajuda da elevação dos corpos vertebrais das lâminas dorsais de T13 e L1; manutenção do ligamento supra-espinhal; colocação de gordura subcutânea como coxim supramedular; sutura da fáscia toracolombar, subcutâneo e pele; e bandagem compressiva por sete dias. Quarenta e oito horas após a cirurgia, todos os 10 cães submetidos a essa técnica exibiram perda das reações posturais e paresia de moderada a grave nos membros pélvicos. Hipoalgesia foi constatada em cinco deles. Tentando descobrir as causas, foram realizados estudos histológicos de medulas espinhais, coletadas 4 e 48 horas após a realização da laminectomia, porém com modificações como: não elevação dos corpos vertebrais durante a cirurgia e prevenção de qualquer tipo de compressão medular após a laminectomia. Analisando esses resultados, foi possível concluir que as disfunções neurológicas decorreram de lesões medulares ocasionadas possivelmente por: elevações dos corpos vertebrais durante a laminectomia, danificação de vasos espinhais, desestabilização da coluna vertebral e uma somatória de forças compressivas atuantes sobre a medula espinhal desprotegida. Na necropsia de cinco cães, acompanhados por quarenta e cinco dias, foi possível constatar: a permanência do ligamento supra-espinhal; que o enxerto de gordura não evita a penetração do tecido fibroso no canal vertebral nem sua aderência à dura- máter; notório (PThe purpose of this research was to check the effects of the Funkquist A dorsal laminectomy in normal dogs. The technique accomplished consisted in dorsal approach to the spine; removal of T13-L1 laminae with or without vertebral bodies elevation; mantainement of the supraspinous ligament; placement of subcutaneous fat as

The ventral hippocampus, but not the dorsal hippocampus is critical for learned approach-avoidance decision making.

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Schumacher, Anett; Vlassov, Ekaterina; Ito, Rutsuko

2016-04-01

The resolution of an approach-avoidance conflict induced by ambivalent information involves the appraisal of the incentive value of the outcomes and associated stimuli to orchestrate an appropriate behavioral response. Much research has been directed at delineating the neural circuitry underlying approach motivation and avoidance motivation separately. Very little research, however, has examined the neural substrates engaged at the point of decision making when opposing incentive motivations are experienced simultaneously. We hereby examine the role of the dorsal and ventral hippocampus (HPC) in a novel approach-avoidance decision making paradigm, revisiting a once popular theory of HPC function, which posited the HPC to be the driving force of a behavioral inhibition system that is activated in situations of imminent threat. Rats received pre-training excitotoxic lesions of the dorsal or ventral HPC, and were trained to associate different non-spatial cues with appetitive, aversive and neutral outcomes in three separate arms of the radial maze. On the final day of testing, a state of approach-avoidance conflict was induced by simultaneously presenting two cues of opposite valences, and comparing the time the rats spent interacting with the superimposed 'conflict' cue, and the neutral cue. The ventral HPC-lesioned group showed significant preference for the conflict cue over the neutral cue, compared to the dorsal HPC-lesioned, and control groups. Thus, we provide evidence that the ventral, but not dorsal HPC, is a crucial component of the neural circuitry concerned with exerting inhibitory control over approach tendencies under circumstances in which motivational conflict is experienced. © 2015 Wiley Periodicals, Inc.

The distribution of excitatory amino acid receptors on acutely dissociated dorsal horn neurons from postnatal rats.

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Arancio, O; Yoshimura, M; Murase, K; MacDermott, A B

1993-01-01

Excitatory amino acid receptor distribution was mapped on acutely dissociated neurons from postnatal rat spinal cord dorsal horn. N-methyl D-aspartate, quisqualate and kainate were applied to multiple locations along the somal and dendritic surfaces of voltage-clamped neurons by means of a pressure application system. To partially compensate for the decrement of response amplitude due to current loss between the site of activation on the dendrite and the recording electrode at the soma, a solution containing 0.15 M KCl was applied on the cell bodies and dendrites of some cells to estimate an empirical length constant. In the majority of the cells tested, the dendritic membrane had regions of higher sensitivity to excitatory amino acid agonists than the somatic membrane, with dendritic response amplitudes reaching more than seven times those at the cell body. A comparison of the relative changes in sensitivity between each combination of two of the three excitatory amino acid agonists along the same dendrite showed different patterns of agonist sensitivity along the dendrite in the majority of the cells. These data were obtained from dorsal horn neurons that had developed and formed synaptic connections in vivo. They demonstrate that in contrast to observations made on ventral horn neurons, receptor density for all the excitatory amino acid receptors on dorsal horn neurons, including the N-methyl-D-aspartate receptor, are generally higher on the dendrites than on the soma. Further, these results are similar to those obtained from dorsal horn neurons grown in culture.

BMPs regulate msx gene expression in the dorsal neuroectoderm of Drosophila and vertebrates by distinct mechanisms.

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Esteves, Francisco F; Springhorn, Alexander; Kague, Erika; Taylor, Erika; Pyrowolakis, George; Fisher, Shannon; Bier, Ethan

2014-09-01

In a broad variety of bilaterian species the trunk central nervous system (CNS) derives from three primary rows of neuroblasts. The fates of these neural progenitor cells are determined in part by three conserved transcription factors: vnd/nkx2.2, ind/gsh and msh/msx in Drosophila melanogaster/vertebrates, which are expressed in corresponding non-overlapping patterns along the dorsal-ventral axis. While this conserved suite of "neural identity" gene expression strongly suggests a common ancestral origin for the patterning systems, it is unclear whether the original regulatory mechanisms establishing these patterns have been similarly conserved during evolution. In Drosophila, genetic evidence suggests that Bone Morphogenetic Proteins (BMPs) act in a dosage-dependent fashion to repress expression of neural identity genes. BMPs also play a dose-dependent role in patterning the dorsal and lateral regions of the vertebrate CNS, however, the mechanism by which they achieve such patterning has not yet been clearly established. In this report, we examine the mechanisms by which BMPs act on cis-regulatory modules (CRMs) that control localized expression of the Drosophila msh and zebrafish (Danio rerio) msxB in the dorsal central nervous system (CNS). Our analysis suggests that BMPs act differently in these organisms to regulate similar patterns of gene expression in the neuroectoderm: repressing msh expression in Drosophila, while activating msxB expression in the zebrafish. These findings suggest that the mechanisms by which the BMP gradient patterns the dorsal neuroectoderm have reversed since the divergence of these two ancient lineages.

BMPs regulate msx gene expression in the dorsal neuroectoderm of Drosophila and vertebrates by distinct mechanisms.

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Francisco F Esteves

2014-09-01

Full Text Available In a broad variety of bilaterian species the trunk central nervous system (CNS derives from three primary rows of neuroblasts. The fates of these neural progenitor cells are determined in part by three conserved transcription factors: vnd/nkx2.2, ind/gsh and msh/msx in Drosophila melanogaster/vertebrates, which are expressed in corresponding non-overlapping patterns along the dorsal-ventral axis. While this conserved suite of "neural identity" gene expression strongly suggests a common ancestral origin for the patterning systems, it is unclear whether the original regulatory mechanisms establishing these patterns have been similarly conserved during evolution. In Drosophila, genetic evidence suggests that Bone Morphogenetic Proteins (BMPs act in a dosage-dependent fashion to repress expression of neural identity genes. BMPs also play a dose-dependent role in patterning the dorsal and lateral regions of the vertebrate CNS, however, the mechanism by which they achieve such patterning has not yet been clearly established. In this report, we examine the mechanisms by which BMPs act on cis-regulatory modules (CRMs that control localized expression of the Drosophila msh and zebrafish (Danio rerio msxB in the dorsal central nervous system (CNS. Our analysis suggests that BMPs act differently in these organisms to regulate similar patterns of gene expression in the neuroectoderm: repressing msh expression in Drosophila, while activating msxB expression in the zebrafish. These findings suggest that the mechanisms by which the BMP gradient patterns the dorsal neuroectoderm have reversed since the divergence of these two ancient lineages.

Neuronal calcium-binding proteins 1/2 localize to dorsal root ganglia and excitatory spinal neurons and are regulated by nerve injury

DEFF Research Database (Denmark)

Zhang, Ming Dong; Tortoriello, Giuseppe; Hsueh, Brian

2014-01-01

, and nerve injury-induced regulation of NECAB1/NECAB2 in mouse dorsal root ganglia (DRGs) and spinal cord. In DRGs, NECAB1/2 are expressed in around 70% of mainly small- and medium-sized neurons. Many colocalize with calcitonin gene-related peptide and isolectin B4, and thus represent nociceptors. NECAB1....../2 neurons are much more abundant in DRGs than the Ca2+-binding proteins (parvalbumin, calbindin, calretinin, and secretagogin) studied to date. In the spinal cord, the NECAB1/2 distribution is mainly complementary. NECAB1 labels interneurons and a plexus of processes in superficial layers of the dorsal horn....... In the dorsal horn, most NECAB1/2 neurons are glutamatergic. Both NECAB1/2 are transported into dorsal roots and peripheral nerves. Peripheral nerve injury reduces NECAB2, but not NECAB1, expression in DRG neurons. Our study identifies NECAB1/2 as abundant Ca2+-binding proteins in pain-related DRG neurons...

Wnt/B-Catenin Signaling is Required to Rescue Midbrain Dopaminergic Progenitors and Promote Neurorepair in Ageing Mouse Model of Parkinson’s Disease

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L’Episcopo, Francesca; Tirolo, Cataldo; Testa, Nunzio; Caniglia, Salvatore; Morale, Maria Concetta; Serapide, Maria Francesca; Pluchino, Stefano; Marchetti, Bianca

2014-01-01

SUMMARY Wnt/β-catenin signaling is required for specification and neurogenesis of midbrain dopaminergic (mDA) neurons, the pivotal neuronal population that degenerates in Parkinson’s disease (PD) and in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. Wnt/β-catenin signaling plays a vital role in adult neurogenesis but whether it might engage DA neurogenesis/neurorepair in the affected PD brain is yet unresolved. Recently, the adult midbrain aqueduct periventricular regions (Aq-PVRs) were shown to harbor neural stem/progenitor cells (mNPCs) with DA potential in vitro, but restrictive mechanisms in vivo are believed to limit their DA regenerative capacity. Using in vitro mNPC culture systems we herein demonstrate that aging is one most critical factor restricting mNPC neurogenic potential via dysregulation of Wnt/β-catenin signaling. Cococulture paradigms between young/aged (Y/A) mNPCs and Y/A astrocytes identified glial age and a decline of glial-derived factors including Wnts as key determinants of impaired neurogenic potential, whereas Wnt activation regimens efficiently reversed the diminished proliferative, neuronal and DA differentiation potential of A-mNPCs. Next, in vivo studies in wild (Wt) and transgenic β-catenin reporter mice uncovered Wnt/β-catenin signaling activation and remarkable astrocyte remodeling of Aq-PVR in response to MPTP-induced DA neuron death. Spatio-temporal analyses unveiled β-catenin signaling in predopaminergic (Nurr1+/TH−) and imperiled or rescuing DAT+ neurons during MPTP-induced DA neuron injury and self-repair. Aging inhibited Wnt signaling, whereas β-catenin activation in situ with a specific GSK-3β antagonist promoted a significant degree of DA neurorestoration associated with reversal of motor deficit, with implications for neurorestorative approaches in PD. PMID:24648001

Kinesthetic working memory and action control within the dorsal stream.

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Fiehler, Katja; Burke, Michael; Engel, Annerose; Bien, Siegfried; Rösler, Frank

2008-02-01

There is wide agreement that the "dorsal (action) stream" processes visual information for movement control. However, movements depend not only on vision but also on tactile and kinesthetic information (=haptics). Using functional magnetic resonance imaging, the present study investigates to what extent networks within the dorsal stream are also utilized for kinesthetic action control and whether they are also involved in kinesthetic working memory. Fourteen blindfolded participants performed a delayed-recognition task in which right-handed movements had to be encoded, maintained, and later recognized without any visual feedback. Encoding of hand movements activated somatosensory areas, superior parietal lobe (dorsodorsal stream), anterior intraparietal sulcus (aIPS) and adjoining areas (ventrodorsal stream), premotor cortex, and occipitotemporal cortex (ventral stream). Short-term maintenance of kinesthetic information elicited load-dependent activity in the aIPS and adjacent anterior portion of the superior parietal lobe (ventrodorsal stream) of the left hemisphere. We propose that the action representation system of the dorsodorsal and ventrodorsal stream is utilized not only for visual but also for kinesthetic action control. Moreover, the present findings demonstrate that networks within the ventrodorsal stream, in particular the left aIPS and closely adjacent areas, are also engaged in working memory maintenance of kinesthetic information.

Patella dislocation with vertical axis rotation: the "dorsal fin" patella.

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Gamble, David; Otto, Quentin; Carrothers, Andrew D; Khanduja, Vikas

2015-01-01

A 44-year-old woman presented following minor trauma to her right knee. While dancing she externally rotated around a planted foot and felt sudden pain in her right knee. She presented with her knee locked in extension with a "dorsal fin" appearance of the soft tissues tented over the patella. This was diagnosed as a rare case of an intraarticular patella dislocation, which was rotated 90 degrees about the vertical axis. Closed reduction in the emergency room was unsuccessful but was achieved in theatre under general anaesthetic with muscle relaxation. Postreduction arthroscopy demonstrated that no osteochondral or soft tissue damage to the knee had been sustained. In patients presenting with a knee locked in extension with tenting of skin over the patella (the "dorsal fin" appearance), intra-articular patella dislocation should be suspected. Attempts to reduce vertical patella dislocations under sedation with excessive force or repeatedly without success should be avoided to prevent unnecessary damage to the patellofemoral joint. In this clinical situation we recommend closed reduction under general anaesthetic followed by immediate knee arthroscopy under the same anaesthetic to ensure that there is no chondral damage to the patella or femoral trochlea and to rule out an osteochondral fracture.

Inflammatory mediators potentiate high affinity GABA(A) currents in rat dorsal root ganglion neurons.

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Lee, Kwan Yeop; Gold, Michael S

2012-06-19

Following acute tissue injury action potentials may be initiated in afferent processes terminating in the dorsal horn of the spinal cord that are propagated back out to the periphery, a process referred to as a dorsal root reflex (DRR). The DRR is dependent on the activation of GABA(A) receptors. The prevailing hypothesis is that DRR is due to a depolarizing shift in the chloride equilibrium potential (E(Cl)) following an injury-induced activation of the Na(+)-K(+)-Cl(-)-cotransporter. Because inflammatory mediators (IM), such as prostaglandin E(2) are also released in the spinal cord following tissue injury, as well as evidence that E(Cl) is already depolarized in primary afferents, an alternative hypothesis is that an IM-induced increase in GABA(A) receptor mediated current (I(GABA)) could underlie the injury-induced increase in DRR. To test this hypothesis, we explored the impact of IM (prostaglandin E(2) (1 μM), bradykinin (10 μM), and histamine (1 μM)) on I(GABA) in dissociated rat dorsal root ganglion (DRG) neurons with standard whole cell patch clamp techniques. IM potentiated I(GABA) in a subpopulation of medium to large diameter capsaicin insensitive DRG neurons. This effect was dependent on the concentration of GABA, manifest only at low concentrations (emergence of injury-induced DRR. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Factors that Affected Functional Outcome After a Delayed Excision and Split-Thickness Skin Graft on the Dorsal Side of Burned Hands.

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Shichinohe, Ryuji; Yamamoto, Yuhei; Kawashima, Kunihiro; Kimura, Chu; Ono, Kentaro; Horiuchi, Katsumi; Yoshida, Tetsunori; Murao, Naoki; Hayashi, Toshihiko; Funayama, Emi; Oyama, Akihiko; Furukawa, Hiroshi

Early excision and skin grafting is the principle treatment for a burned hand although there are occasions when it cannot be done such as severe general condition, delayed consultation, and the lack of a definitive assessment of burn depth. This study analyzes the factors that affected function after a delayed excision and skin graft for hands with a deep dermal burn. This study retrospectively evaluated 43 burned hands that required a delayed excision and split-thickness skin graft on the dorsal side. Cases were required to only have split-thickness skin grafting from the dorsum of the hand and fingers distally to at least the proximal interphalangeal joint at least 8 days after the injury. The hands were divided into two functional categories: Functional category A, normal or nearly normal joint movements, and functional category B, abnormal joint movements. Demographic data were assessed statistically by a univariate analysis following a multiple regression analysis by a stepwise selection. A significant difference was observed between the groups in the number of days from grafting to complete wound healing of the graft site and with or without an escharotomy in the analysis. These parameters were statistically significant predictors of functional category B. The functional outcome of a burned hand after a delayed excision and split-thickness skin graft on the dorsal side became degraded depending on the number of days from grafting to complete wound healing. Cases that underwent an escharotomy also showed deterioration in function.

Optic ataxia and the function of the dorsal stream: contributions to perception and action.

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Pisella, Laure; Sergio, Lauren; Blangero, Annabelle; Torchin, Héloïse; Vighetto, Alain; Rossetti, Yves

2009-12-01

Optic ataxia (OA) is one of the symptoms pertaining to Bálint's Syndrome. It has been described clinically for nearly 80 years before it became a cornerstone of the most popular dual stream theory of the visual brain. Over the last 10 years a regain of interest for this neurological condition lead to a number of precise analyses of the deficits found in optic ataxia, giving rise to a renewed outline of its very definition and hence of the function(s) of the occipito-parietal (dorsal) stream. In absence of concomitant clinical symptoms, we review evidence that misreaching errors in central vision result from the "hand effect": an erroneous dynamic spatial processing of proprioceptive information from the hand. When visual feedback of the hand is provided (closed-loop condition), pure optic ataxia is restricted to peripheral vision. This central versus peripheral vision distinction is repeatedly used to argue that action and perception are not unique and dissociated systems. New assessments of optic ataxia patients are provided, confirming on one hand that their visuomotor deficit is specific to peripheral vision (i.e. when the gaze and the hand goals are dissociated), on the other hand that they disclose perceptual deficits in peripheral vision. These results are coherent with the recent demonstration that optic ataxia patients exhibit a general contralesional deficit for dynamic visuo-spatial processing, affecting both hand and eye movements [Gaveau, V., Pélisson, D., Blangero, A., Urquizar, C., Prablanc, C.,Vighetto, A., et al. (2008). A common parietal module for saccade and reach: Eye-hand coordination and saccadic control in optic ataxia. Neuropsychologia, 46, 475-486]. Such module(s) within the dorsal stream could be used for both action and perception in the periphery. It is concluded that optic ataxia cannot be considered as a unitary and specific visuo-manual deficit, and that the modular organisation of the dorsal stream allows for numerous dorsal

Cross-hemispheric dopamine projections have functional significance

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

2016-01-01

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

Supersensitive detection and discrimination of enantiomers by dorsal olfactory receptors: evidence for hierarchical odour coding.

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Sato, Takaaki; Kobayakawa, Reiko; Kobayakawa, Ko; Emura, Makoto; Itohara, Shigeyoshi; Kizumi, Miwako; Hamana, Hiroshi; Tsuboi, Akio; Hirono, Junzo

2015-09-11

Enantiomeric pairs of mirror-image molecular structures are difficult to resolve by instrumental analyses. The human olfactory system, however, discriminates (-)-wine lactone from its (+)-form rapidly within seconds. To gain insight into receptor coding of enantiomers, we compared behavioural detection and discrimination thresholds of wild-type mice with those of ΔD mice in which all dorsal olfactory receptors are genetically ablated. Surprisingly, wild-type mice displayed an exquisite "supersensitivity" to enantiomeric pairs of wine lactones and carvones. They were capable of supersensitive discrimination of enantiomers, consistent with their high detection sensitivity. In contrast, ΔD mice showed selective major loss of sensitivity to the (+)-enantiomers. The resulting 10(8)-fold differential sensitivity of ΔD mice to (-)- vs. (+)-wine lactone matched that observed in humans. This suggests that humans lack highly sensitive orthologous dorsal receptors for the (+)-enantiomer, similarly to ΔD mice. Moreover, ΔD mice showed >10(10)-fold reductions in enantiomer discrimination sensitivity compared to wild-type mice. ΔD mice detected one or both of the (-)- and (+)-enantiomers over a wide concentration range, but were unable to discriminate them. This "enantiomer odour discrimination paradox" indicates that the most sensitive dorsal receptors play a critical role in hierarchical odour coding for enantiomer identification.

The Onecut Transcription Factors Regulate Differentiation and Distribution of Dorsal Interneurons during Spinal Cord Development

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Karolina U. Kabayiza

2017-05-01

Full Text Available During embryonic development, the dorsal spinal cord generates numerous interneuron populations eventually involved in motor circuits or in sensory networks that integrate and transmit sensory inputs from the periphery. The molecular mechanisms that regulate the specification of these multiple dorsal neuronal populations have been extensively characterized. In contrast, the factors that contribute to their diversification into smaller specialized subsets and those that control the specific distribution of each population in the developing spinal cord remain unknown. Here, we demonstrate that the Onecut transcription factors, namely Hepatocyte Nuclear Factor-6 (HNF-6 (or OC-1, OC-2 and OC-3, regulate the diversification and the distribution of spinal dorsal interneuron (dINs. Onecut proteins are dynamically and differentially distributed in spinal dINs during differentiation and migration. Analyzes of mutant embryos devoid of Onecut factors in the developing spinal cord evidenced a requirement in Onecut proteins for proper production of a specific subset of dI5 interneurons. In addition, the distribution of dI3, dI5 and dI6 interneuron populations was altered. Hence, Onecut transcription factors control genetic programs that contribute to the regulation of spinal dIN diversification and distribution during embryonic development.

Contribution of the dorsal noradrenergic bundle to the effect of amphetamine on acetylcholine turnover

International Nuclear Information System (INIS)

Robinson, S.E.

1986-01-01

In order to determine the contribution of the noradrenergic projections of the locus coeruleus to the action of amphetamine on cholinergic neurons in several areas of the brain, the dorsal noradrenergic bundle was selectively lesioned by injection of the neurotoxin 6-hydroxydopamine. The bundles of Equithesin-anesthetized male rats were lesioned bilaterally by stereotaxically-placed injections of 6-OHDA. The animals were killed in the microwave and constant rate infusion with phosphoryl ( 2 H 9 )-choline was begun. Levels of ACh and choline and TR /SUB ACh/ were determined by a mass fragmentographic technique. Rats not exhibiting the proper decrease in NE were excluded from all data calculations. It is shown that noradrenergic neurons travelling in the dorsal noradrenergic bundle do not exert a tonic action on cholinergic neurons in the cortex, hippocampus or hypothalamus

Divergent axial morphogenesis and early shh expression in vertebrate prospective floor plate

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Stanislav Kremnyov

2018-01-01

Full Text Available Abstract Background The notochord has organizer properties and is required for floor plate induction and dorsoventral patterning of the neural tube. This activity has been attributed to sonic hedgehog (shh signaling, which originates in the notochord, forms a gradient, and autoinduces shh expression in the floor plate. However, reported data are inconsistent and the spatiotemporal development of the relevant shh expression domains has not been studied in detail. We therefore studied the expression dynamics of shh in rabbit, chicken and Xenopus laevis embryos (as well as indian hedgehog and desert hedgehog as possible alternative functional candidates in the chicken. Results Our analysis reveals a markedly divergent pattern within these vertebrates: whereas in the rabbit shh is first expressed in the notochord and its floor plate domain is then induced during subsequent somitogenesis stages, in the chick embryo shh is expressed in the prospective neuroectoderm prior to the notochord formation and, interestingly, prior to mesoderm immigration. Neither indian hedgehog nor desert hedgehog are expressed in these midline structures although mRNA of both genes was detected in other structures of the early chick embryo. In X. laevis, shh is expressed at the beginning of gastrulation in a distinct area dorsal to the dorsal blastopore lip and adjacent to the prospective neuroectoderm, whereas the floor plate expresses shh at the end of gastrulation. Conclusions While shh expression patterns in rabbit and X. laevis embryos are roughly compatible with the classical view of “ventral to dorsal induction” of the floor plate, the early shh expression in the chick floor plate challenges this model. Intriguingly, this alternative sequence of domain induction is related to the asymmetrical morphogenesis of the primitive node and other axial organs in the chick. Our results indicate that the floor plate in X. laevis and chick embryos may be initially

Agenesis of dorsal pancreas with eventration of diaphragm and intrapancreatic pseudocyst: a rare entity

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Poras Chaudhary

2013-02-01

Full Text Available A case of acute pancreatitis in a 43-year-old male patient, which was eventually diagnosed as agenesis of dorsal pancreas with eventration of left hemidiaphragm and intrapancreatic pseudocyst is being reported.

Preputial skin free graft as dorsal onlay urethroplasty: Our experience of 73 patients.

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Bapat, Shivadeo S; Padhye, Abhijit S; Yadav, Pushkaraj B; Bhave, Ashish A

2007-10-01

To present the outcome of dorsal onlay urethroplasty in 73 patients for stricture urethra over a period of eight years. Seventy-three patients of stricture urethra have undergone dorsal onlay urethroplasty from July 1998 to February 2006. Age distribution: 14-58 years. Trauma 20/73 (27.39%), Balanitis Xerotica Obliterans 2/73 (2.73%), Iatrogenic 26/73(35.61%), Infection 3/73 (4.10%), Idiopathic 22/73 (30.13%). Site: Penobulbar-25/73, bulbar-38/73, membranous-8/73 and long length-2/73. Suprapubic catheter was inserted preoperatively: 21/73 patients. Preputial / distal penile skin was used in all patients. Buccal mucosa was not used in any patient. Hospitalization was for four to five days. Catheter was removed after 21 days. All patients had their first endoscopic checkup after three months. Subsequently they were followed up by uroflometry. Routine imaging of urethra for follow-up was not carried out. 63/73 (86.30%) patients had satisfactory outcome not requiring any further treatment, 8/73 (10.95%) developed anastomotic stricture (3/8-optical internal urethrotomy, 5/8 dilatation alone). 2/73 (2.75%) developed external meatal stenosis. None had urinary fistula and required repeat urethroplasty. Follow-up ranged from three months to eight years. Dorsal onlay urethroplasty using preputial/distal penile skin is a satisfactory procedure. Preputial/distal penile skin is devoid of hair and fat and hence an ideal graft material. Even in circumscribed patients distal penile skin can be harvested. Long-term follow-up is required in judging results of patients with stricture urethra.

Characteristics of intraoperative abnormal hemodynamics during resection of an intra-fourth ventricular tumor located on the dorsal medulla oblongata.

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Ideguchi, Makoto; Kajiwara, Koji; Yoshikawa, Koichi; Sadahiro, Hirokazu; Nomura, Sadahiro; Fujii, Masami; Suzuki, Michiyasu

2013-01-01

Abnormal hemodynamics during extirpation of a para-medulla oblongata (MO) tumor is common and may be associated with direct vagal stimulation of the medullary circuit. However, resection of tumors on the dorsal MO may also induce hemodynamic instability without direct vagal stimulus. The objective of this study was to examine the characteristics of hemodynamic instability unrelated to vagal stimulus during dissection of an intra-fourth ventricular tumor with attachment to the dorsal MO. A retrospective analysis was performed in 13 patients. Abnormal hemodynamics were defined as a > 20% change from the means of the intraoperative mean arterial pressure (MAP) and heart rate (HR). Relationships of intraoperative hemodynamics were evaluated with various parameters, including the volume of the MO. Six patients (46.2%) had intraoperative hypertension during separation of the tumor bulk from the dorsal MO. The maximum MAP and HR in these patients were significantly greater than those in patients with normal hemodynamics (116.0 ± 18.0 mmHg versus 85.6 ± 6.5 mmHg; 124.3 ± 22.8 bpm versus 90.5 ± 14.7 bpm). All six cases with abnormal hemodynamics showed hemodynamic fluctuation during separation of the tumor bulk from the dorsal MO. The preoperative volume of the MO in these patients was 1.11 cc less than that in patients with normal hemodynamics, but the volume after tumor resection was similar in the two groups (5.23 cc and 5.12 cc). This suggests that the MO was compressed by the conglutinate tumor bulk, with resultant fluctuation of hemodynamics. Recognition of and preparation for this phenomenon are important for surgery on a tumor located on the dorsal MO.

Unique caudal plumage of Jeholornis and complex tail evolution in early birds

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O’Connor, Jingmai; Wang, Xiaoli; Sullivan, Corwin; Zheng, Xiaoting; Tubaro, Pablo; Zhang, Xiaomei; Zhou, Zhonghe

2013-01-01

The Early Cretaceous bird Jeholornis was previously only known to have a distally restricted ornamental frond of tail feathers. We describe a previously unrecognized fan-shaped tract of feathers situated dorsal to the proximal caudal vertebrae. The position and morphology of these feathers is reminiscent of the specialized upper tail coverts observed in males of some sexually dimorphic neornithines. As in the neornithine tail, the unique “two-tail” plumage in Jeholornis probably evolved as th...

Fat opacities dorsal to the equine antebrachiocarpal joint

International Nuclear Information System (INIS)

Dietze, A.E.; Rendano, V.T.

1984-01-01

Radiolucencies due to fat in the soft tissues dorsal to the equine antebrachiocarpal joint were studied in 12 necropsy specimens. In lateral-to-medial xeroradiographs of these 12 specimens, focal radiolucencies were present in ten, one focal radiolucency was present in one, and no focal radiolucencies were present in ten, one focal radiolucency was present in one, and no focal radiolucencies were in another. These radiolucencies were identified as fat in the antebrachiocarpal joint capsule. The fat was in two locations within this joint capsule. It was associated with the synovial membrane of the extensor carpi radialis tendon sheath and the synovial membrane of the antebrachiocarpal joint

Incomplete oblique sagittal fractures of the dorsal cortex of the third metacarpal bone in six horses

International Nuclear Information System (INIS)

Watt, B.C.; Foerner, J.J.; Haines, G.R.

1998-01-01

To describe incomplete oblique sagittal dorsal cortical fractures of the equine third metacarpal bone, their surgical repair, and subsequent performance of the horses. Retrospective examination of medical records and racing performance. Six Thoroughbred race horses, 2 to 4 years of age. Radiographic confirmation of all fractures preceded general anesthesia and surgical correction. Three fractures were treated by intracortical compression using screws placed in lag fashion, and five fractures were treated by osteostixis. Race records were reviewed for each horse to determine performance after surgery. Fractures were best observed on palmarodorsal radiographic projections. Three horses treated by intracortical compression returned to racing, but fracture recurred in one horse and was treated by osteostixis. This horse and the other three horses treated by osteostixis raced after surgery. Horses with incomplete oblique sagittal fractures of the dorsal cortex of the third metacarpal bone can race after surgical management of the fracture by screws placed in lag fashion or osteostixis. The authors' preferred surgical procedure for managing this fracture is osteostixis. Palmarodorsal radiographic projections of the third metacarpal bone are recommended in young Thoroughbred race horses suspected of having dorsal metacarpal stress fractures

Successful conservative management of symptomatic bilateral dorsal patellar defects presenting with cartilage involvement and bone marrow edema: MRI findings.

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Kwee, Thomas C; Sonneveld, Heleen; Nix, Maarten

2016-05-01

The dorsal patellar defect is a relatively rare entity that involves the superolateral quadrant of the patella. It is usually considered to represent a delayed ossification process, although its exact origin remains unclear. Because of its usually innocuous nature and clinical course, invasive interventions are generally deemed unnecessary, although curretage has been successfully performed on symptomatic cases. This case report presents a rather unusual case of symptomatic bilateral dorsal patellar defects with cartilage involvement and widespread surrounding bone marrow edema as demonstrated by magnetic resonance imaging (MRI). Both cartilage involvement and bone marrow edema should be considered part of the spectrum of associated MRI findings that can be encountered in this entity. Furthermore, the presented case shows that symptomatic dorsal patellar defects can be treated conservatively with success and that (decrease of) pain symptoms are likely related to (decrease of) bone marrow edema.

GLT1 overexpression reverses established neuropathic pain-related behavior and attenuates chronic dorsal horn neuron activation following cervical spinal cord injury.

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Falnikar, Aditi; Hala, Tamara J; Poulsen, David J; Lepore, Angelo C

2016-03-01

Development of neuropathic pain occurs in a major portion of traumatic spinal cord injury (SCI) patients, resulting in debilitating and often long-term physical and psychological burdens. Following SCI, chronic dysregulation of extracellular glutamate homeostasis has been shown to play a key role in persistent central hyperexcitability of superficial dorsal horn neurons that mediate pain neurotransmission, leading to various forms of neuropathic pain. Astrocytes express the major CNS glutamate transporter, GLT1, which is responsible for the vast majority of functional glutamate uptake, particularly in the spinal cord. In our unilateral cervical contusion model of mouse SCI that is associated with ipsilateral forepaw heat hypersensitivity (a form of chronic at-level neuropathic pain-related behavior), we previously reported significant and long-lasting reductions in GLT1 expression and functional GLT1-mediated glutamate uptake in cervical spinal cord dorsal horn. To therapeutically address GLT1 dysfunction following cervical contusion SCI, we injected an adeno-associated virus type 8 (AAV8)-Gfa2 vector into the superficial dorsal horn to increase GLT1 expression selectively in astrocytes. Compared to both contusion-only animals and injured mice that received AAV8-eGFP control injection, AAV8-GLT1 delivery increased GLT1 protein expression in astrocytes of the injured cervical spinal cord dorsal horn, resulting in a significant and persistent reversal of already-established heat hypersensitivity. Furthermore, AAV8-GLT1 injection significantly reduced expression of the transcription factor and marker of persistently increased neuronal activation, ΔFosB, in superficial dorsal horn neurons. These results demonstrate that focal restoration of GLT1 expression in the superficial dorsal horn is a promising target for treating chronic neuropathic pain following SCI. © 2015 Wiley Periodicals, Inc.

Luxations carpo-métacarpiennes dorsales du quatrième et ...

African Journals Online (AJOL)

Nous rapportons le cas d'une luxation carpo-métacarpienne dorsale quatrième et cinquième métacarpiens chez un jeune homme de 46 ans, droitier, agent de sécurité, qui à la suite d'un coup d'énervement donne un coup poing contre le mur (mécanisme indirect) entrainant une douleur et impotence fonctionnelle totale de ...

Immunostaining for Homer reveals the majority of excitatory synapses in laminae I?III of the mouse spinal dorsal horn

OpenAIRE

Gutierrez-Mecinas, Maria; Kuehn, Emily D.; Abraira, Victoria E.; Polg?r, Erika; Watanabe, Masahiko; Todd, Andrew J.

2016-01-01

The spinal dorsal horn processes somatosensory information before conveying it to the brain. The neuronal organization of the dorsal horn is still poorly understood, although recent studies have defined several distinct populations among the interneurons, which account for most of its constituent neurons. All primary afferents, and the great majority of neurons in laminae I–III are glutamatergic, and a major factor limiting our understanding of the synaptic circuitry has been the difficulty i...

Reassessment of the wing feathers of Archaeopteryx lithographica suggests no robust evidence for the presence of elongated dorsal wing coverts.

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Robert L Nudds

Full Text Available Recently it was proposed that the primary feathers of Archaeopteryx lithographica (HMN1880 were overlaid by long covert feathers, and that a multilayered feathered wing was a feature of early fossils with feathered forelimbs. The proposed long covert feathers of Archaeopteryx were previously interpreted as dorsally displaced remiges or a second set of impressions made by the wing. The following study shows that the qualitative arguments forwarded in support of the elongated covert hypothesis are neither robust nor supported quantitatively. The idea that the extant bird wing with its single layer of overlapping primaries evolved from an earlier multilayered heavily coveted feathered forelimb as seen in Anchiornis huxleyi is reasonable. At this juncture, however, it is premature to conclude unequivocally that the wing of Archaeopteryx consisted of primary feathers overlaid with elongated coverts.

Ultrasonographic anatomy of the dorsal and abaxial aspects of the equine fetlock.

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Denoix, J M; Jacot, S; Bousseau, B; Perrot, P

1996-01-01

This paper describes normal ultrasound images of the soft tissues of the dorsal and abaxial aspects of the equine fetlock. The palmar aspect of the fetlock is not discussed because it is related to the suspensory apparatus and flexor tendon anatomy which has been previously described. Ultrasound scanning was performed with 7.5 MHz linear or 10 MHz sector probes and recorded on 7.5 cm U-matic videocassettes allowing further retrospective data analysis, computer manipulation and good image reproducibility. Sagittal, parasagittal, frontal and transverse ultrasound scans of 13 lameness free mature horses were compared to anatomically dissected leg specimens, anatomical sections and Magnetic Resonance Imaging scans of isolated limbs. The results are focused on the comparison between anatomical sections and ultrasonograms performed on the legs of nonlame horses. Ultrasonography was demonstrated to be a very accurate imaging procedure for soft tissue structures at the dorsal and abaxial aspects of the equine fetlock. Under clinical conditions, a thorough knowledge of normal ultrasonographic anatomy is critical for an accurate diagnosis of fetlock soft tissue injury.

Selective functional dysconnectivity of the dorsal-anterior subregion of the precuneus in drug-naive major depressive disorder.

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Zhu, Jiajia; Lin, Xiaodong; Lin, Chongguang; Zhuo, Chuanjun; Yu, Yongqiang

2018-01-01

Patients with major depressive disorder (MDD) have shown altered resting-state functional connectivity (rsFC) of the precuneus; however, it is unknown whether rsFC of the precuneus subregions is differentially affected in this disorder. In this study, we aimed to clarify this issue by comparing rsFC of each precuneus subregion between patients with MDD and healthy controls. Forty-seven drug-naive patients with MDD and 47 sex-, age- and education-matched healthy controls underwent resting-state functional magnetic resonance imaging (fMRI). The precuneus was divided into PCun-1 (dorsal-central portion; medial area 7), PCun-2 (dorsal-anterior portion; medial area 5), PCun-3 (dorsal-posterior portion; dorsomedial parietooccipital sulcus) and PCun-4 (ventral portion; area 31). The rsFC of each precuneus subregion was compared between the two groups. Compared with healthy controls, patients with MDD exhibited increased rsFC between the left PCun-2 and the right fusiform gyrus, lateral prefrontal cortex, sensorimotor cortex and supramarginal gyrus. No significant inter-group difference was observed in the rsFC of other precuneus subregions. In addition, there was no difference in gray matter volume of all the precuneus subregions between patients with MDD and healthy controls. Some of the patients had chronic MDD and relevant neuropsychological data were not collected. These findings suggest a selective functional dysconnectivity of the precuneus subregions in drug-naive MDD, characterized by the hyperconnnectivity between the dorsal-anterior subregion and regions involved in visual, executive control, sensorimotor and bottom-up attention functions. Copyright © 2017 Elsevier B.V. All rights reserved.

The Development of Dorsal Nasal Cyst Formation after Rhinoplasty and Its Reconstruction with Conchal Cartilage

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Tolgar Lütfi Kumral

2014-01-01

Full Text Available The dorsal nasal cyst formation is a rare and late complication of rhinoplasty. It has been rarely reported in the literature and it is usually mucous cysts. Migration and planting to the subcutaneous space during the surgical procedure has been recognized as the formation mechanism. This case report has presented 42-year-old male patient with a destructing dorsal nasal mucous cyst that developed 10 years after the rhinoplasty operation. There was no complication in the primary rhinoplasty and the patient was satisfied with his appearance. There was a swelling of the nasal dorsum over the past year and surgical excision of the cyst was performed. During the surgery, the defect was reconstructed with conchal cartilage. There was no recurrence during follow-up.

Adult neurogenesis is reduced in the dorsal hippocampus of rats displaying learned helplessness behavior.

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Ho, Y C; Wang, S

2010-11-24

Clinical and preclinical studies suggest that the hippocampus has a role in the pathophysiology of major depression. In the learned helplessness (LH) animal model of depression after inescapable shocks (ISs) animals that display LH behavior have reduced cell proliferation in the hippocampus; this effect can be reversed by antidepressant treatment. Using this model, we compared rats that displayed LH behavior and rats that did not show LH behavior (NoLH) after ISs to determine whether reduced hippocampal cell proliferation is associated with the manifestation of LH behavior or is a general response to stress. Specifically, we examined cell proliferation, neurogenesis, and synaptic function in dorsal and ventral hippocampus of LH and NoLH animals and control rats that were not shocked. The LH rats had showed reduced cell proliferation, neurogenesis, and synaptic transmission in the dorsal hippocampus, whereas no changes were seen in the ventral hippocampus. These changes were not observed in the NoLH animals. In a group of NoLH rats that received the same amount of electrical shock as the LH rats to control for the unequal shocks received in these two groups, we observed changes in Ki-67(+) cells associated with acute stress. We conclude that reduced hippocampal cell proliferation and neurogenesis are associated with the manifestation of LH behavior and that the dorsal hippocampus is the most affected area. Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

A role for Runx transcription factor signaling in dorsal root ganglion sensory neuron diversification.

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Kramer, Ina; Sigrist, Markus; de Nooij, Joriene C; Taniuchi, Ichiro; Jessell, Thomas M; Arber, Silvia

2006-02-02

Subpopulations of sensory neurons in the dorsal root ganglion (DRG) can be characterized on the basis of sensory modalities that convey distinct peripheral stimuli, but the molecular mechanisms that underlie sensory neuronal diversification remain unclear. Here, we have used genetic manipulations in the mouse embryo to examine how Runx transcription factor signaling controls the acquisition of distinct DRG neuronal subtype identities. Runx3 acts to diversify an Ngn1-independent neuronal cohort by promoting the differentiation of proprioceptive sensory neurons through erosion of TrkB expression in prospective TrkC+ sensory neurons. In contrast, Runx1 controls neuronal diversification within Ngn1-dependent TrkA+ neurons by repression of neuropeptide CGRP expression and controlling the fine pattern of laminar termination in the dorsal spinal cord. Together, our findings suggest that Runx transcription factor signaling plays a key role in sensory neuron diversification.

Dorsal-ventral patterning in amphioxus: current understanding, unresolved issues, and future directions

Czech Academy of Sciences Publication Activity Database

Kozmiková, Iryna; Yu, J.K.

2017-01-01

Roč. 61, č. 10-12 (2017), s. 601-610 ISSN 0214-6282 R&D Projects: GA ČR GC15-21285J Institutional support: RVO:68378050 Keywords : dorsal-ventral patterning * organizer * signaling pathway * chordate * evolution Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 1.981, year: 2016

fMRI Evidence for Dorsal Stream Processing Abnormality in Adults Born Preterm

Science.gov (United States)

Chaminade, Thierry; Leutcher, Russia Ha-Vinh; Millet, Veronique; Deruelle, Christine

2013-01-01

We investigated the consequences of premature birth on the functional neuroanatomy of the dorsal stream of visual processing. fMRI was recorded while sixteen healthy participants, 8 (two men) adults (19 years 6 months old, SD 10 months) born premature (mean gestational age 30 weeks), referred to as Premas, and 8 (two men) matched controls (20…

Evaluation of the effects of dorsal versus lateral recumbency on the cardiopulmonary system during anesthesia with isoflurane in red-tailed hawks (Buteo jamaicensis).

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Hawkins, Michelle G; Malka, Shachar; Pascoe, Peter J; Solano, Adrian M; Kass, Philip H; Ohmura, Hajime; Jones, James H

2013-01-01

To evaluate the effects of dorsal versus lateral recumbency on the cardiopulmonary system during isoflurane anesthesia in red-tailed hawks (Buteo jamaicensis). 6 adult 1.1- to 1.6-kg red-tailed hawks. A randomized, crossover study was used to evaluate changes in respiratory rate, tidal volume, minute ventilation, heart rate, mean arterial and indirect blood pressures, and end-tidal Pco(2) measured every 5 minutes plus Paco(2) and Pao(2) and arterial pH measured every 15 minutes throughout a 75-minute study period. Respiratory rate was higher, tidal volume lower, and minute ventilation not different in lateral versus dorsal recumbency. Position did not affect heart rate, mean arterial blood pressure, or indirect blood pressure, although heart rate decreased during the anesthetic period. Birds hypoventilated in both positions and Paco(2) differed with time and position × time interaction. The Petco(2) position × time interaction was significant and Petco(2) was a mean of 7 Torr higher than Paco(2). The Paco(2) in dorsal recumbency was a mean of 32 Torr higher than in lateral recumbency. Birds in both positions developed respiratory acidosis. Differences in tidal volume with similar minute ventilation suggested red-tailed hawks in dorsal recumbency might have lower dead space ventilation. Despite similar minute ventilation in both positions, birds in dorsal recumbency hypoventilated more yet maintained higher Pao(2), suggesting parabronchial ventilatory or pulmonary blood flow distribution changes with position. The results refute the hypothesis that dorsal recumbency compromises ventilation and O(2) transport more than lateral recumbency in red-tailed hawks.

Successful conservative management of symptomatic bilateral dorsal patellar defects presenting with cartilage involvement and bone marrow edema: MRI findings

International Nuclear Information System (INIS)

Kwee, Thomas C.; Sonneveld, Heleen; Nix, Maarten

2016-01-01

The dorsal patellar defect is a relatively rare entity that involves the superolateral quadrant of the patella. It is usually considered to represent a delayed ossification process, although its exact origin remains unclear. Because of its usually innocuous nature and clinical course, invasive interventions are generally deemed unnecessary, although curretage has been successfully performed on symptomatic cases. This case report presents a rather unusual case of symptomatic bilateral dorsal patellar defects with cartilage involvement and widespread surrounding bone marrow edema as demonstrated by magnetic resonance imaging (MRI). Both cartilage involvement and bone marrow edema should be considered part of the spectrum of associated MRI findings that can be encountered in this entity. Furthermore, the presented case shows that symptomatic dorsal patellar defects can be treated conservatively with success and that (decrease of) pain symptoms are likely related to (decrease of) bone marrow edema. (orig.)

Successful conservative management of symptomatic bilateral dorsal patellar defects presenting with cartilage involvement and bone marrow edema: MRI findings

Energy Technology Data Exchange (ETDEWEB)

Kwee, Thomas C. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); Meander Medical Center, Department of Radiology, Amersfoort (Netherlands); Sonneveld, Heleen [Meander Medical Center, Department of Orthopaedics, Amersfoort (Netherlands); Nix, Maarten [Meander Medical Center, Department of Radiology, Amersfoort (Netherlands)

2016-05-15

The dorsal patellar defect is a relatively rare entity that involves the superolateral quadrant of the patella. It is usually considered to represent a delayed ossification process, although its exact origin remains unclear. Because of its usually innocuous nature and clinical course, invasive interventions are generally deemed unnecessary, although curretage has been successfully performed on symptomatic cases. This case report presents a rather unusual case of symptomatic bilateral dorsal patellar defects with cartilage involvement and widespread surrounding bone marrow edema as demonstrated by magnetic resonance imaging (MRI). Both cartilage involvement and bone marrow edema should be considered part of the spectrum of associated MRI findings that can be encountered in this entity. Furthermore, the presented case shows that symptomatic dorsal patellar defects can be treated conservatively with success and that (decrease of) pain symptoms are likely related to (decrease of) bone marrow edema. (orig.)

Comparison of the Schirmer tear test I values after placement in ventral and dorsal conjunctival fornices in healthy cats.

Science.gov (United States)

Aftab, Ghazal; Rajaei, Seyed Mehdi; Faghihi, Houman

2017-09-01

Objectives The objective of this study was to compare the Schirmer tear test I values obtained from placement of Schirmer tear test (STT) strips in ventral and dorsal conjunctival fornices and to investigate any correlation between age, body weight and STT values in clinically normal cats. Methods Twenty-eight intact adult domestic shorthair and Persian were used in this study. The cats were gently physically restrained in a sternal position, and a Schirmer tear strip was placed on each eye in the ventral conjunctival fornix at one-third of the distance from the temporal to nasal canthus for 60 s. Then, the wetted portion of the strips was measured as mm/min (L-STT I). After 48 h, the same procedure was performed on each eye in the dorsal conjunctival fornix (U-STT I). Results Mean ± SD STT values of the ventral and dorsal conjunctival fornices were 20.80 ± 2.25 mm/min (range 14-25 mm/min; 95% confidence interval [CI] 19.92-21.67) and 18.28 ± 2.27 mm/min (range 15-22 mm/min; 95% CI 17.39-19.16) in all of the study population, respectively. A significant difference was found between STT values obtained from the ventral and dorsal conjunctival fornices ( P <0.001). There was no correlation between the age and body weight of the animals and STT I values. Conclusions and relevance This study compared the STT I values of the dorsal and ventral conjunctival fornices in cats. The difference was significant between the L-STT I and U-STT I values; however, the L-STT I and U-STT I values were within normal reference intervals. The U-STT I data have diagnostic value that might be of benefit in cases where there is a problem in the ventral conjunctival fornix.

Dorsal bundle lesions do not affect latent inhibition of conditioned suppression.

Science.gov (United States)

Tsaltas, E; Preston, G C; Rawlins, J N; Winocur, G; Gray, J A

1984-01-01

Three experiments are reported which examine the effects of lesions of the dorsal ascending noradrenergic bundle (DB) on latent inhibition using a conditioned suppression procedure in rats. In none of the experiments did the DB lesion have any effect, despite changes in the extent of latent inhibition and in the control procedures used to assess it. The results are discussed in relation to the attentional theory of DB function.

Nucleocytoplasmic shuttling mediates the dynamic maintenance of nuclear Dorsal levels during Drosophila embryogenesis

DEFF Research Database (Denmark)

DeLotto, Robert; DeLotto, Yvonne; Steward, Ruth

2007-01-01

, including nuclei on the dorsal side. Nuclear export is blocked by leptomycin B, a potent inhibitor of Exportin 1 (CRM1)-mediated nuclear export. We have developed a novel in vivo assay revealing the presence of a functional leucine-rich nuclear export signal within the carboxyterminal 44 amino acids...

High plasticity in epithelial morphogenesis during insect dorsal closure

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Kristen A. Panfilio

2013-09-01

Insect embryos complete the outer form of the body via dorsal closure (DC of the epidermal flanks, replacing the transient extraembryonic (EE tissue. Cell shape changes and morphogenetic behavior are well characterized for DC in Drosophila, but these data represent a single species with a secondarily reduced EE component (the amnioserosa that is not representative across the insects. Here, we examine DC in the red flour beetle, Tribolium castaneum, providing the first detailed, functional analysis of DC in an insect with complete EE tissues (distinct amnion and serosa. Surprisingly, we find that differences between Drosophila and Tribolium DC are not restricted to the EE tissue, but also encompass the dorsal epidermis, which differs in cellular architecture and method of final closure (zippering. We then experimentally manipulated EE tissue complement via RNAi for Tc-zen1, allowing us to eliminate the serosa and still examine viable DC in a system with a single EE tissue (the amnion. We find that the EE domain is particularly plastic in morphogenetic behavior and tissue structure. In contrast, embryonic features and overall kinetics are robust to Tc-zen1RNAi manipulation in Tribolium and conserved with a more distantly related insect, but remain substantially different from Drosophila. Although correct DC is essential, plasticity and regulative, compensatory capacity have permitted DC to evolve within the insects. Thus, DC does not represent a strong developmental constraint on the nature of EE development, a property that may have contributed to the reduction of the EE component in the fly lineage.

Monorail/Foxa2 regulates floorplate differentiation and specification of oligodendrocytes, serotonergic raphé neurones and cranial motoneurones.

Science.gov (United States)

Norton, Will H; Mangoli, Maryam; Lele, Zsolt; Pogoda, Hans-Martin; Diamond, Brianne; Mercurio, Sara; Russell, Claire; Teraoka, Hiroki; Stickney, Heather L; Rauch, Gerd-Jörg; Heisenberg, Carl-Philipp; Houart, Corinne; Schilling, Thomas F; Frohnhoefer, Hans-Georg; Rastegar, Sepand; Neumann, Carl J; Gardiner, R Mark; Strähle, Uwe; Geisler, Robert; Rees, Michelle; Talbot, William S; Wilson, Stephen W

2005-02-01

In this study, we elucidate the roles of the winged-helix transcription factor Foxa2 in ventral CNS development in zebrafish. Through cloning of monorail (mol), which we find encodes the transcription factor Foxa2, and phenotypic analysis of mol-/- embryos, we show that floorplate is induced in the absence of Foxa2 function but fails to further differentiate. In mol-/- mutants, expression of Foxa and Hh family genes is not maintained in floorplate cells and lateral expansion of the floorplate fails to occur. Our results suggest that this is due to defects both in the regulation of Hh activity in medial floorplate cells as well as cell-autonomous requirements for Foxa2 in the prospective laterally positioned floorplate cells themselves. Foxa2 is also required for induction and/or patterning of several distinct cell types in the ventral CNS. Serotonergic neurones of the raphenucleus and the trochlear motor nucleus are absent in mol-/- embryos, and oculomotor and facial motoneurones ectopically occupy ventral CNS midline positions in the midbrain and hindbrain. There is also a severe reduction of prospective oligodendrocytes in the midbrain and hindbrain. Finally, in the absence of Foxa2, at least two likely Hh pathway target genes are ectopically expressed in more dorsal regions of the midbrain and hindbrain ventricular neuroepithelium, raising the possibility that Foxa2 activity may normally be required to limit the range of action of secreted Hh proteins.

Glutamate/glutamine concentrations in the dorsal anterior cingulate vary with Post-Traumatic Stress Disorder symptoms.

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Harnett, Nathaniel G; Wood, Kimberly H; Ference, Edward W; Reid, Meredith A; Lahti, Adrienne C; Knight, Amy J; Knight, David C

2017-08-01

Trauma and stress-related disorders (e.g., Acute Stress Disorder; ASD and Post-Traumatic Stress Disorder; PTSD) that develop following a traumatic event are characterized by cognitive-affective dysfunction. The cognitive and affective functions disrupted by stress disorder are mediated, in part, by glutamatergic neural systems. However, it remains unclear whether neural glutamate concentrations, measured acutely following trauma, vary with ASD symptoms and/or future PTSD symptom expression. Therefore, the current study utilized proton magnetic resonance spectroscopy ( 1 H-MRS) to investigate glutamate/glutamine (Glx) concentrations within the dorsal anterior cingulate cortex (ACC) of recently (i.e., within one month) traumatized individuals and non-traumatized controls. Although Glx concentrations within dorsal ACC did not differ between recently traumatized and non-traumatized control groups, a positive linear relationship was observed between Glx concentrations and current stress disorder symptoms in traumatized individuals. Further, Glx concentrations showed a positive linear relationship with future stress disorder symptoms (i.e., assessed 3 months post-trauma). The present results suggest glutamate concentrations may play a role in both acute and future post-traumatic stress symptoms following a traumatic experience. The current results expand our understanding of the neurobiology of stress disorder and suggest glutamate within the dorsal ACC plays an important role in cognitive-affective dysfunction following a traumatic experience. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preputial skin free graft as dorsal onlay urethroplasty: Our experience of 73 patients

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Shivadeo S Bapat

2007-01-01

Full Text Available Objective: To present the outcome of dorsal onlay urethroplasty in 73 patients for stricture urethra over a period of eight years. Materials and Methods: Seventy-three patients of stricture urethra have undergone dorsal onlay urethroplasty from July 1998 to February 2006. Age distribution: 14-58 years. Etiology: Trauma 20/73 (27.39%, Balanitis Xerotica Obliterans 2/73 (2.73%, Iatrogenic 26/73(35.61%, Infection 3/73 (4.10%, Idiopathic 22/73 (30.13%. Site: Penobulbar-25/73, bulbar-38/73, membranous-8/73 and long length-2/73. Suprapubic catheter was inserted preoperatively: 21/73 patients. Preputial / distal penile skin was used in all patients. Buccal mucosa was not used in any patient. Hospitalization was for four to five days. Catheter was removed after 21 days. All patients had their first endoscopic checkup after three months. Subsequently they were followed up by uroflometry. Routine imaging of urethra for follow-up was not carried out. Results: 63/73 (86.30% patients had satisfactory outcome not requiring any further treatment, 8/73 (10.95% developed anastomotic stricture (3/8-optical internal urethrotomy, 5/8 dilatation alone. 2/73 (2.75% developed external meatal stenosis. None had urinary fistula and required repeat urethroplasty. Follow-up ranged from three months to eight years. Conclusion: Dorsal onlay urethroplasty using preputial/distal penile skin is a satisfactory procedure. Preputial/distal penile skin is devoid of hair and fat and hence an ideal graft material. Even in circumscribed patients distal penile skin can be harvested. Long-term follow-up is required in judging results of patients with stricture urethra.

The influence of cannabinoids on learning and memory processes of the dorsal striatum.

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Goodman, Jarid; Packard, Mark G

2015-11-01

Extensive evidence indicates that the mammalian endocannabinoid system plays an integral role in learning and memory. Our understanding of how cannabinoids influence memory comes predominantly from studies examining cognitive and emotional memory systems mediated by the hippocampus and amygdala, respectively. However, recent evidence suggests that cannabinoids also affect habit or stimulus-response (S-R) memory mediated by the dorsal striatum. Studies implementing a variety of maze tasks in rats indicate that systemic or intra-dorsolateral striatum infusions of cannabinoid receptor agonists or antagonists impair habit memory. In mice, cannabinoid 1 (CB1) receptor knockdown can enhance or impair habit formation, whereas Δ(9)THC tolerance enhances habit formation. Studies in human cannabis users also suggest an enhancement of S-R/habit memory. A tentative conclusion based on the available data is that acute disruption of the endocannabinoid system with either agonists or antagonists impairs, whereas chronic cannabinoid exposure enhances, dorsal striatum-dependent S-R/habit memory. CB1 receptors are required for multiple forms of striatal synaptic plasticity implicated in memory, including short-term and long-term depression. Interactions with the hippocampus-dependent memory system may also have a role in some of the observed effects of cannabinoids on habit memory. The impairing effect often observed with acute cannabinoid administration argues for cannabinoid-based treatments for human psychopathologies associated with a dysfunctional habit memory system (e.g. post-traumatic stress disorder and drug addiction/relapse). In addition, the enhancing effect of repeated cannabinoid exposure on habit memory suggests a novel neurobehavioral mechanism for marijuana addiction involving the dorsal striatum-dependent memory system. Copyright © 2015 Elsevier Inc. All rights reserved.

Comparative gene expression analysis of Dtg, a novel target gene of Dpp signaling pathway in the early Drosophila melanogaster embryo.

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Hodar, Christian; Zuñiga, Alejandro; Pulgar, Rodrigo; Travisany, Dante; Chacon, Carlos; Pino, Michael; Maass, Alejandro; Cambiazo, Verónica

2014-02-10

In the early Drosophila melanogaster embryo, Dpp, a secreted molecule that belongs to the TGF-β superfamily of growth factors, activates a set of downstream genes to subdivide the dorsal region into amnioserosa and dorsal epidermis. Here, we examined the expression pattern and transcriptional regulation of Dtg, a new target gene of Dpp signaling pathway that is required for proper amnioserosa differentiation. We showed that the expression of Dtg was controlled by Dpp and characterized a 524-bp enhancer that mediated expression in the dorsal midline, as well as, in the differentiated amnioserosa in transgenic reporter embryos. This enhancer contained a highly conserved region of 48-bp in which bioinformatic predictions and in vitro assays identified three Mad binding motifs. Mutational analysis revealed that these three motifs were necessary for proper expression of a reporter gene in transgenic embryos, suggesting that short and highly conserved genomic sequences may be indicative of functional regulatory regions in D. melanogaster genes. Dtg orthologs were not detected in basal lineages of Dipterans, which unlike D. melanogaster develop two extra-embryonic membranes, amnion and serosa, nevertheless Dtg orthologs were identified in the transcriptome of Musca domestica, in which dorsal ectoderm patterning leads to the formation of a single extra-embryonic membrane. These results suggest that Dtg was recruited as a new component of the network that controls dorsal ectoderm patterning in the lineage leading to higher Cyclorrhaphan flies, such as D. melanogaster and M. domestica. Copyright © 2013 Elsevier B.V. All rights reserved.

Guyon's canal syndrome due to tortuous ulnar artery with DeQuervain stenosing tenosynovitis, ligamentous injuries and dorsal intercalated segmental instability syndrome, a rare presentation: a case report.

Science.gov (United States)

Zeeshan, Muhammad; Ahmed, Farhan; Kanwal, Darakhshan; Khalid, Qazi Saad Bin; Ahmed, Muhammad Nadeem

2009-12-23

The Guyon's canal syndrome is a well known clinical entity and may have significant impact on patient's quality of life. We report a case of 43-year-old male who presented with complaints of pain and numbness in right hand and difficulty in writing for past one month. On imaging diagnosis of Guyon's canal syndrome because of tortuous ulnar artery was made with additional findings of DeQuervain's stenosing tenosynovitis and dorsal intercalated segmental instability syndrome with ligamentous injury and subsequently these were confirmed on surgery.Although it is a rare syndrome, early diagnosis and treatment prevents permanent neurological deficits and improve patient's quality of life.

The Ste20 kinase misshapen regulates both photoreceptor axon targeting and dorsal closure, acting downstream of distinct signals.

Science.gov (United States)

Su, Y C; Maurel-Zaffran, C; Treisman, J E; Skolnik, E Y

2000-07-01

We have previously shown that the Ste20 kinase encoded by misshapen (msn) functions upstream of the c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase module in Drosophila. msn is required to activate the Drosophila JNK, Basket (Bsk), to promote dorsal closure of the embryo. A mammalian homolog of Msn, Nck interacting kinase, interacts with the SH3 domains of the SH2-SH3 adapter protein Nck. We now show that Msn likewise interacts with Dreadlocks (Dock), the Drosophila homolog of Nck. dock is required for the correct targeting of photoreceptor axons. We have performed a structure-function analysis of Msn in vivo in Drosophila in order to elucidate the mechanism whereby Msn regulates JNK and to determine whether msn, like dock, is required for the correct targeting of photoreceptor axons. We show that Msn requires both a functional kinase and a C-terminal regulatory domain to activate JNK in vivo in Drosophila. A mutation in a PXXP motif on Msn that prevents it from binding to the SH3 domains of Dock does not affect its ability to rescue the dorsal closure defect in msn embryos, suggesting that Dock is not an upstream regulator of msn in dorsal closure. Larvae with only this mutated form of Msn show a marked disruption in photoreceptor axon targeting, implicating an SH3 domain protein in this process; however, an activated form of Msn is not sufficient to rescue the dock mutant phenotype. Mosaic analysis reveals that msn expression is required in photoreceptors in order for their axons to project correctly. The data presented here genetically link msn to two distinct biological events, dorsal closure and photoreceptor axon pathfinding, and thus provide the first evidence that Ste20 kinases of the germinal center kinase family play a role in axonal pathfinding. The ability of Msn to interact with distinct classes of adapter molecules in dorsal closure and photoreceptor axon pathfinding may provide the flexibility that allows it to link to distinct

Axotomy increases NADPH-diaphorase activity in the dorsal root ganglia and lumbar spinal cord of the turtle Trachemys dorbigni

OpenAIRE

Partata,W.A.; Krepsky,A.M.R.; Marques,M.; Achaval,M.

1999-01-01

Seven days after transection of the sciatic nerve NADPH-diaphorase activity increased in the small and medium neurons of the dorsal root ganglia of the turtle. However, this increase was observed only in medium neurons for up to 90 days. At this time a bilateral increase of NADPH-diaphorase staining was observed in all areas and neuronal types of the dorsal horn, and in positive motoneurons in the lumbar spinal cord, ipsilateral to the lesion. A similar increase was also demonstrable in spina...

Patella Dislocation with Vertical Axis Rotation: The “Dorsal Fin” Patella

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David Gamble

2015-01-01

Full Text Available A 44-year-old woman presented following minor trauma to her right knee. While dancing she externally rotated around a planted foot and felt sudden pain in her right knee. She presented with her knee locked in extension with a “dorsal fin” appearance of the soft tissues tented over the patella. This was diagnosed as a rare case of an intraarticular patella dislocation, which was rotated 90 degrees about the vertical axis. Closed reduction in the emergency room was unsuccessful but was achieved in theatre under general anaesthetic with muscle relaxation. Postreduction arthroscopy demonstrated that no osteochondral or soft tissue damage to the knee had been sustained. In patients presenting with a knee locked in extension with tenting of skin over the patella (the “dorsal fin” appearance, intra-articular patella dislocation should be suspected. Attempts to reduce vertical patella dislocations under sedation with excessive force or repeatedly without success should be avoided to prevent unnecessary damage to the patellofemoral joint. In this clinical situation we recommend closed reduction under general anaesthetic followed by immediate knee arthroscopy under the same anaesthetic to ensure that there is no chondral damage to the patella or femoral trochlea and to rule out an osteochondral fracture.

Running Reduces Uncontrollable Stress-Evoked Serotonin and Potentiates Stress-Evoked Dopamine Concentrations in the Rat Dorsal Striatum.

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Peter J Clark

Full Text Available Accumulating evidence from both the human and animal literature indicates that exercise reduces the negative consequences of stress. The neurobiological etiology for this stress protection, however, is not completely understood. Our lab reported that voluntary wheel running protects rats from expressing depression-like instrumental learning deficits on the shuttle box escape task after exposure to unpredictable and inescapable tail shocks (uncontrollable stress. Impaired escape behavior is a result of stress-sensitized serotonin (5-HT neuron activity in the dorsal raphe (DRN and subsequent excessive release of 5-HT into the dorsal striatum following exposure to a comparatively mild stressor. However, the possible mechanisms by which exercise prevents stress-induced escape deficits are not well characterized. The purpose of this experiment was to test the hypothesis that exercise blunts the stress-evoked release of 5-HT in the dorsal striatum. Changes to dopamine (DA levels were also examined, since striatal DA signaling is critical for instrumental learning and can be influenced by changes to 5-HT activity. Adult male F344 rats, housed with or without running wheels for 6 weeks, were either exposed to tail shock or remained undisturbed in laboratory cages. Twenty-four hours later, microdialysis was performed in the medial (DMS and lateral (DLS dorsal striatum to collect extracellular 5-HT and DA before, during, and following 2 mild foot shocks. We report wheel running prevents foot shock-induced elevation of extracellular 5-HT and potentiates DA concentrations in both the DMS and DLS approximately 24 h following exposure to uncontrollable stress. These data may provide a possible mechanism by which exercise prevents depression-like instrumental learning deficits following exposure to acute stress.

Scanning electron microscopy of the dorsal vessel of Panstrongylus megistus (Burmeister, 1835 (Hemiptera: Reduviidae

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Nadir Francisca Sant'Anna Nogueira

1991-03-01

Full Text Available In this study we analyzed the microanatomy of the dorsal vessel of the triatomine Panstrongylus megistus. The organ is a tuble anatomically divided into an anterior aorta anad a posterior heart, connected to the body wall through 8 pairs of alary muscles. The heart is divided in 3 chambers by means of 2 pairs of cardiac valves. a pair of ostia can be observed in the lateral wall of each chamber. A bundle of nerve fibers was found outside the organ, running dorsally along its major axis. A group of longitudinal muscular fibers was found in the ventral portion of the vessel. The vessel was found to be lined both internally and externally by pericardial cells covered by a thin laminar membrane. Inseide the vessel the pericardial cells were disposed in layers and on the outside they formed clusters or rows.

Patterns of triangular fibrocartilage complex (TFCC) injury associated with severely dorsally displaced extra-articular distal radius fractures.

Science.gov (United States)

Scheer, Johan H; Adolfsson, Lars E

2012-06-01

The aim of the study was to examine triangular fibrocartilage (TFCC) injury patterns associated with unstable, extra-articular dorsally displaced distal radius fractures. Twenty adult patients with an Arbeitsgemeinschaft für Osteosynthesefragen (AO), type A2 or A3, distal radius fracture with an initial dorsal angulation greater than 20° were included. Nine had a tip fracture (distal to the base) of the ulnar styloid and 11 had no such fracture. They were all openly explored from an ulnopalmar approach and TFCC injuries were documented. Eleven patients also underwent arthroscopy and intra-articular pathology was recorded. All patients had TFCC lesions of varying severity, having an extensor carpi ulnaris subsheath avulsion in common. Eighteen out of 20 also displayed deep foveal radioulnar ligament lesions, with decreasingly dorsal fibres remaining. The extent of this foveal injury could not be appreciated by radiocarpal arthroscopy. Severe displacement of an extra-articular radius fracture suggests an ulnar-sided ligament injury to the TFCC. The observed lesions concur with findings in a previous cadaver study. The lesions follow a distinct pattern affecting both radioulnar as well as ulnocarpal stabilisers. Copyright © 2012 Elsevier Ltd. All rights reserved.

Homeobox gene expression in adult dorsal root ganglia: Is regeneration a recapitulation of development?

NARCIS (Netherlands)

Vogelaar, C.F.

2003-01-01

Neurons of the peripheral nervous system are able to regenerate their peripheral axons after injury, leading to complete recovery of sensory and motor function. The sciatic nerve crush model is frequently used to study peripheral nerve regeneration. Sensory neurons in the dorsal root ganglia (DRGs)

Synaptically evoked glutamate transporter currents in Spinal Dorsal Horn Astrocytes

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Dougherty Patrick M

2009-07-01

Full Text Available Abstract Background Removing and sequestering synaptically released glutamate from the extracellular space is carried out by specific plasma membrane transporters that are primarily located in astrocytes. Glial glutamate transporter function can be monitored by recording the currents that are produced by co-transportation of Na+ ions with the uptake of glutamate. The goal of this study was to characterize glutamate transporter function in astrocytes of the spinal cord dorsal horn in real time by recording synaptically evoked glutamate transporter currents. Results Whole-cell patch clamp recordings were obtained from astrocytes in the spinal substantia gelatinosa (SG area in spinal slices of young adult rats. Glutamate transporter currents were evoked in these cells by electrical stimulation at the spinal dorsal root entry zone in the presence of bicuculline, strychnine, DNQX and D-AP5. Transporter currents were abolished when synaptic transmission was blocked by TTX or Cd2+. Pharmacological studies identified two subtypes of glutamate transporters in spinal astrocytes, GLAST and GLT-1. Glutamate transporter currents were graded with stimulus intensity, reaching peak responses at 4 to 5 times activation threshold, but were reduced following low-frequency (0.1 – 1 Hz repetitive stimulation. Conclusion These results suggest that glutamate transporters of spinal astrocytes could be activated by synaptic activation, and recording glutamate transporter currents may provide a means of examining the real time physiological responses of glial cells in spinal sensory processing, sensitization, hyperalgesia and chronic pain.

Modifications in resting state functional anticorrelation between default mode network and dorsal attention network: comparison among young adults, healthy elders and mild cognitive impairment patients.

Science.gov (United States)

Esposito, Roberto; Cieri, Filippo; Chiacchiaretta, Piero; Cera, Nicoletta; Lauriola, Mariella; Di Giannantonio, Massimo; Tartaro, Armando; Ferretti, Antonio

2018-02-01

Resting state brain activity incorporates different components, including the Default Mode Network and the Dorsal Attention Network, also known as task-negative network and task-positive network respectively. These two networks typically show an anticorrelated activity during both spontaneous oscillations and task execution. However modifications of this anticorrelated activity pattern with age and pathology are still unclear. The present study aimed to investigate differences in resting state Default Mode Network-Dorsal Attention Network functional anticorrelation among young adults, healthy elders and Mild Cognitive Impairment patients. We retrospectively enrolled in this study 27 healthy young adults (age range: 25-35 y.o.; mean age: 28,5), 26 healthy elders (age range: 61-72 y.o.; mean age: 65,1) and 17 MCI patients (age range 64-87 y.o.; mean age: 73,6). Mild Cognitive Impairment patients were selected following Petersen criteria. All participants underwent neuropsychological evaluation and resting state functional Magnetic Resonance Imaging. Spontaneous anticorrelated activity between Default Mode Network and Dorsal Attention Network was observed in each group. This anticorrelation was significantly decreased with age in most Default Mode Network-Dorsal Attention Network connections (p Default Mode Network and the right inferior parietal sulcus node of the Dorsal Attention Network was significantly decreased when comparing Mild Cognitive Impairment with normal elders (p Default Mode Network and Dorsal Attention Network is part of the normal aging process and that Mild Cognitive Impairment status is associated with more evident inter-networks functional connectivity changes.

Neuromodulatory effects of the dorsal hippocampal endocannabinoid system in dextromethorphan/morphine-induced amnesia.

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Ghasemzadeh, Zahra; Rezayof, Ameneh

2017-01-05

Dextromethorphan which is an active ingredient in many cough medicines has been previously shown to potentiate amnesic effect of morphine in rats. However, the effect of dextromethorphan, that is also a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, in combination with morphine on hippocampus-based long term memory has not been well characterized. The aim of the present study was to assess the possible role of endocannabinoid system of the dorsal hippocampus in dextromethorphan /morphine-induced amnesia. Our results showed that intraperitoneal (i.p.) injection of morphine (5mg/kg) or dextromethorphan (5-15mg/kg) before testing the passive avoidance learning induced amnesia. Combination of ineffective doses of dextromethorphan (7.5mg/kg, i.p.) and morphine (2mg/kg, i.p.) also produced amnesia, suggesting the enhancing effects of the drugs. To assess the effect of the activation or inhibition of the dorsal hippocampal cannabinoid CB 1 receptors on this amnesia, ACPA or AM251 as selective receptor agonists or antagonists were respectively injected into the CA1 regions before systemic injection of dextromethorphan and morphine. Interestingly, intra-CA1 microinjection of ACPA (0.5-1ng/rat) improved the amnesic effect of dextromethorphan /morphine combination. The microinjection of AM251 into the CA1 region enhanced the response of the combination of dextromethorphan /morphine in inducing amnesia. Moreover, Intra-CA1 microinjection of AM251 inhibited the improving effect of ACPA on dextromethorphan /morphine-induced amnesia. It is important to note that intra-CA1 microinjection of the same doses of the agonist or antagonist by itself had no effects on memory formation. Thus, it can be concluded that the dorsal hippocampal endocannabinoid system, via CB 1 receptor-dependent mechanism, may be involved in morphine/dextromethorphan -induced amnesia. Copyright © 2016 Elsevier B.V. All rights reserved.

Electrolytic Lesions of the Dorsal Hippocampus Disrupt Renewal of Conditional Fear after Extinction

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Ji, Jinzhao; Maren, Stephen

2005-01-01

There is a growing body of evidence that the hippocampus is critical for context-dependent memory retrieval. In the present study, we used Pavlovian fear conditioning in rats to examine the role of the dorsal hippocampus (DH) in the context-specific expression of fear memory after extinction (i.e., renewal). Pre-training electrolytic lesions of…

Coordinated Ramping of Dorsal Striatal Pathways preceding Food Approach and Consumption.

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London, Tanisha D; Licholai, Julia A; Szczot, Ilona; Ali, Mohamed A; LeBlanc, Kimberly H; Fobbs, Wambura C; Kravitz, Alexxai V

2018-04-04

The striatum controls food-related actions and consumption and is linked to feeding disorders, including obesity and anorexia nervosa. Two populations of neurons project from the striatum: direct pathway medium spiny neurons and indirect pathway medium spiny neurons. The selective contribution of direct pathway medium spiny neurons and indirect pathway medium spiny neurons to food-related actions and consumption remains unknown. Here, we used in vivo electrophysiology and fiber photometry in mice (of both sexes) to record both spiking activity and pathway-specific calcium activity of dorsal striatal neurons during approach to and consumption of food pellets. While electrophysiology revealed complex task-related dynamics across neurons, population calcium was enhanced during approach and inhibited during consumption in both pathways. We also observed ramping changes in activity that preceded both pellet-directed actions and spontaneous movements. These signals were heterogeneous in the spiking units, with neurons exhibiting either increasing or decreasing ramps. In contrast, the population calcium signals were homogeneous, with both pathways having increasing ramps of activity for several seconds before actions were initiated. An analysis comparing population firing rates to population calcium signals also revealed stronger ramping dynamics in the calcium signals than in the spiking data. In a second experiment, we trained the mice to perform an action sequence to evaluate when the ramping signals terminated. We found that the ramping signals terminated at the beginning of the action sequence, suggesting they may reflect upcoming actions and not preconsumption activity. Plasticity of such mechanisms may underlie disorders that alter action selection, such as drug addiction or obesity. SIGNIFICANCE STATEMENT Alterations in striatal function have been linked to pathological consumption in disorders, such as obesity and drug addiction. We recorded spiking and

Impaired communication between the dorsal and ventral stream: indications from apraxia

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Carys eEvans

2016-02-01

Full Text Available Patients with apraxia perform poorly when demonstrating how an object is used, particularly when pantomiming the action. However, these patients are able to accurately identify, and to pick up and move objects, demonstrating intact ventral and dorsal stream visuomotor processing. Appropriate object manipulation for skilled use is thought to rely on integration of known and visible object properties associated with ‘ventro-dorsal’ stream neural processes. In apraxia, it has been suggested that stored object knowledge from the ventral stream may be less readily available to incorporate into the action plan, leading to an over-reliance on the objects’ visual affordances in object-directed motor behaviour. The current study examined grasping performance in left hemisphere stroke patients with (N = 3 and without (N = 9 apraxia, and in age-matched healthy control participants (N = 14, where participants repeatedly grasped novel cylindrical objects of varying weight distribution. Across two conditions, object weight distribution was indicated by either a memory-associated cue (object colour or visual-spatial cue (visible dot over the weighted end. Participants were required to incorporate object-weight associations to effectively grasp and balance each object. Control groups appropriately adjusted their grasp according to each object’s weight distribution across each condition, whereas throughout the task two of the three apraxic patients performed poorly on both the memory-associated and visual-spatial cue conditions. A third apraxic patient seemed to compensate for these difficulties but still performed differently to control groups. Patients with apraxia performed normally on the neutral control condition when grasping the evenly weighted version. The pattern of behaviour in apraxic patients suggests impaired integration of visible and known object properties attributed to the ventro-dorsal stream: in learning to grasp the weighted object

Parkin and PINK1 Patient iPSC-Derived Midbrain Dopamine Neurons Exhibit Mitochondrial Dysfunction and α-Synuclein Accumulation

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Sun Young Chung

2016-10-01

Full Text Available Parkinson's disease (PD is characterized by the selective loss of dopamine neurons in the substantia nigra; however, the mechanism of neurodegeneration in PD remains unclear. A subset of familial PD is linked to mutations in PARK2 and PINK1, which lead to dysfunctional mitochondria-related proteins Parkin and PINK1, suggesting that pathways implicated in these monogenic forms could play a more general role in PD. We demonstrate that the identification of disease-related phenotypes in PD-patient-specific induced pluripotent stem cell (iPSC-derived midbrain dopamine (mDA neurons depends on the type of differentiation protocol utilized. In a floor-plate-based but not a neural-rosette-based directed differentiation strategy, iPSC-derived mDA neurons recapitulate PD phenotypes, including pathogenic protein accumulation, cell-type-specific vulnerability, mitochondrial dysfunction, and abnormal neurotransmitter homeostasis. We propose that these form a pathogenic loop that contributes to disease. Our study illustrates the promise of iPSC technology for examining PD pathogenesis and identifying therapeutic targets.

Parkin and PINK1 Patient iPSC-Derived Midbrain Dopamine Neurons Exhibit Mitochondrial Dysfunction and α-Synuclein Accumulation.

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Chung, Sun Young; Kishinevsky, Sarah; Mazzulli, Joseph R; Graziotto, John; Mrejeru, Ana; Mosharov, Eugene V; Puspita, Lesly; Valiulahi, Parvin; Sulzer, David; Milner, Teresa A; Taldone, Tony; Krainc, Dimitri; Studer, Lorenz; Shim, Jae-Won

2016-10-11

Parkinson's disease (PD) is characterized by the selective loss of dopamine neurons in the substantia nigra; however, the mechanism of neurodegeneration in PD remains unclear. A subset of familial PD is linked to mutations in PARK2 and PINK1, which lead to dysfunctional mitochondria-related proteins Parkin and PINK1, suggesting that pathways implicated in these monogenic forms could play a more general role in PD. We demonstrate that the identification of disease-related phenotypes in PD-patient-specific induced pluripotent stem cell (iPSC)-derived midbrain dopamine (mDA) neurons depends on the type of differentiation protocol utilized. In a floor-plate-based but not a neural-rosette-based directed differentiation strategy, iPSC-derived mDA neurons recapitulate PD phenotypes, including pathogenic protein accumulation, cell-type-specific vulnerability, mitochondrial dysfunction, and abnormal neurotransmitter homeostasis. We propose that these form a pathogenic loop that contributes to disease. Our study illustrates the promise of iPSC technology for examining PD pathogenesis and identifying therapeutic targets. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Retraction: Borroto-Escuela et al., The existence of FGFR1-5-HT1A receptor heterocomplexes in midbrain 5-HT neurons of the rat: relevance for neuroplasticity.

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2013-07-10

The Journal of Neuroscience has received a report describing an investigation by the Karolinska Institutet, which found substantial data misrepresentation in the article "The Existence of FGFR1-5-HT1A Receptor Heterocomplexes in Midbrain 5-HT Neurons of the Rat: Relevance for Neuroplasticity" by Dasiel O. Borroto-Escuela, Wilber Romero-Fernandez, Mileidys Pérez-Alea, Manuel Narvaez, Alexander O. Tarakanov, Giuseppa Mudó , Luigi F. Agnati, Francisco Ciruela, Natale Belluardo, and Kjell Fuxe, which appeared on pages 6295-6303 of the May 2, 2012 issue. Because the results cannot be considered reliable, the editors of The Journal are retracting the paper.

Cotterillia bromelicola nov. gen., nov. spec., a gonostomatid ciliate (Ciliophora, Hypotricha) from tank bromeliads (Bromeliaceae) with de novo originating dorsal kineties.

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Foissner, Wilhelm; Stoeck, Thorsten

2011-01-01

Cotterillia bromelicola nov. gen., nov. spec. was discovered in the tanks of the Mexican bromeliad Tillandsia heterophylla. Its morphology, ontogenesis, and 18S rDNA were studied with standard methods. Cotterillia has many cirral rows on both sides of the body. Uniquely, and thus used to diagnose the new genus Cotterillia, it has dorsal kineties originating de novo, producing neokinetal waves where the parental dorsal kineties reorganize to "combined rows", consisting of dorsal bristles anteriorly and of cirri posteriorly. Thus, up to four generations of bristles and cirri occur on the dorsal body surface. Cotterillia bromelicola has a gonostomatid body and adoral zone of membranelles, while the dense ciliature and the neokinetal waves resemble kahliellid hypotrichs. However, the de novo origin of anlage 1 and the molecular analyses show convincingly that Cotterillia belongs to the GonostomatidaeSmall and Lynn, 1985, for which an improved diagnosis is provided. Thus, neokinetal waves originated several times independently. The molecular differences between Trachelostyla, Gonostomum, and Cotterillia are small (≤ 5%) compared to their distinct morphologies and ontogeneses, suggesting that the 18S rDNA underestimates generic diversity. Our study emphasizes the need of combined morphological, ontogenetic, and molecular investigations to unravel the complex phylogeny and evolution of hypotrich ciliates. Published by Elsevier GmbH.

Intracerebroventricular Administration of Amyloid β-protein Oligomers Selectively Increases Dorsal Hippocampal Dialysate Glutamate Levels in the Awake Rat

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Sean D. O’Shea

2008-11-01

Full Text Available Extensive evidence supports an important role for soluble oligomers of the amyloid β-protein (Aβ in Alzheimer’s Disease pathogenesis. In the present study we combined intracerebroventricular (icv injections with brain microdialysis technology in the fully conscious rat to assess the effects of icv administered SDS-stable low-n Aβ oligomers (principally dimers and trimers on excitatory and inhibitory amino acid transmission in the ipsilateral dorsal hippocampus. Microdialysis was employed to assess the effect of icv administration of Aβ monomers and Aβ oligomers on dialysate glutamate, aspartate and GABA levels in the dorsal hippocampus. Administration of Aβ oligomers was associated with a +183% increase (p<0.0001 vs. Aβ monomer-injected control in dorsal hippocampal glutamate levels which was still increasing at the end of the experiment (260 min, whereas aspartate and GABA levels were unaffected throughout. These findings demonstrate that icv administration and microdialysis technology can be successfully combined in the awake rat and suggests that altered dorsal hippocampal glutamate transmission may be a useful target for pharmacological intervention in Alzheimer’s Disease.

The paramedian supracerebellar infratentorial approach.

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La Pira, Biagia; Sorenson, Thomas; Quillis-Quesada, Vicent; Lanzino, Giuseppe

2017-08-01

Lesions of the superior cerebellar surface, pineal region, lateral and dorsal midbrain and mesial temporal lobe are challenging to treat and often require neurosurgical intervention. The paramedian variation of the supracerebellar infratentorial approach utilizes the downward slope of the cerebellum to facilitate exposure and the lower density of cerebellar bridging veins away from the midline decreases the need to sacrifice larger venous channels. We also discuss our experiences with the approach, and some of the drawbacks and nuances that we have encountered as it has evolved over the years. This approach is versatile and effective and the authors' surgical approach of choice for resecting these challenging lesions.

Superficial dorsal horn neurons with double spike activity in the rat.

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Rojas-Piloni, Gerardo; Dickenson, Anthony H; Condés-Lara, Miguel

2007-05-29

Superficial dorsal horn neurons promote the transfer of nociceptive information from the periphery to supraspinal structures. The membrane and discharge properties of spinal cord neurons can alter the reliability of peripheral signals. In this paper, we analyze the location and response properties of a particular class of dorsal horn neurons that exhibits double spike discharge with a very short interspike interval (2.01+/-0.11 ms). These neurons receive nociceptive C-fiber input and are located in laminae I-II. Double spikes are generated spontaneously or by depolarizing current injection (interval of 2.37+/-0.22). Cells presenting double spike (interval 2.28+/-0.11) increased the firing rate by electrical noxious stimulation, as well as, in the first minutes after carrageenan injection into their receptive field. Carrageenan is a polysaccharide soluble in water and it is used for producing an experimental model of semi-chronic pain. In the present study carrageenan also produces an increase in the interval between double spikes and then, reduced their occurrence after 5-10 min. The results suggest that double spikes are due to intrinsic membrane properties and that their frequency is related to C-fiber nociceptive activity. The present work shows evidence that double spikes in superficial spinal cord neurones are related to the nociceptive stimulation, and they are possibly part of an acute pain-control mechanism.

Polidocanol injection for chemical delay and its effect on the survival of rat dorsal skin flaps.

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Menevşe, Gülsüm Tetik; TeomanTellioglu, Ali; Altuntas, Nurgül; Cömert, Ayhan; Tekdemir, Ibrahim

2014-06-01

Surgical delay is an invasive method requiring a two-stage surgical procedure. Hence, methods that may serve as an alternative to surgical delay have become the focus of interest of research studies. From a conceptual view, any technique that interrupts the blood flow along the edges of a proposed flap will render the flap ischemic and induce a delay phenomenon. Polidocanol (Aethoxysklerol(®)-Kreussler) was initially used as a local anesthetic. Nowadays, it has been used as a sclerosing agent to treat telangiectasias and varicose veins. The aim of this experimental study was to investigate the effects of polidocanol injected around the periphery of a random flap as a sclerosing agent on flap delay and survival in a random flap model. A preliminary histopathologic study was performed on two rats to evaluate the sclerosing effect and distribution of polidocanol injection. After the preliminary study, the main study was carried out with three groups: group 1: dorsal flap (n = 10); group 2: dorsal flap + surgical delay (n = 10), group 3: dorsal flap + chemical delay (n = 10). Tissue samples obtained from the flap and injection area revealed destruction of intradermal vessels. The area affected with sclerosis was limited to 0.1 cm beyond the injection site. Mean viable flap areas were 52.1 ± 4.38% (44.0-58.2) in group 1, 64.8 ± 8.92% (57.2-89.2) in group 2, and 71.8 ± 5.18% (64.0-84.0) in group 3. A statistically highly significant difference was found between the surgical delay and chemical delay groups versus the group without delay (p injection around the dorsal flap in the rat is a safe and easy method for nonsurgical delay. The results have shown a flap survival benefit that is superior to controls and equivalent to surgical delay. The clinical application of polidocanol, already in clinical practice for occlusal of telangiectasias, for surgical delay appears feasible. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons

Electrical high frequency stimulation in the dorsal striatum: Effects on response learning and on GABA levels in rats.

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Schumacher, Anett; de Vasconcelos, Anne Pereira; Lecourtier, Lucas; Moser, Andreas; Cassel, Jean-Christophe

2011-09-23

Electrical high frequency stimulation (HFS) has been used to treat various neurological and psychiatric diseases. The striatal area contributes to response learning and procedural memory. Therefore, we investigated the effect of striatal HFS application on procedural/declarative-like memory in rats. All rats were trained in a flooded Double-H maze for three days (4 trials/day) to swim to an escape platform hidden at a constant location. The starting place was the same for all trials. After each training session, HFS of the left dorsal striatum was performed over 4h in alternating 20 min periods (during rest time, 10a.m. to 3p.m.). Nineteen hours after the last HFS and right after a probe trial assessing the rats' strategy (procedural vs. declarative-like memory-based choice), animals were sacrificed and the dorsal striatum was quickly removed. Neurotransmitter levels were measured by HPLC. Stimulated rats did not differ from sham-operated and control rats in acquisition performance, but exhibited altered behavior during the probe trial (procedural memory responses being less frequent than in controls). In stimulated rats, GABA levels were significantly increased in the dorsal striatum on both sides. We suggest that HFS of the dorsal striatum does not alter learning behavior in rats but influences the strategy by which the rats solve the task. Given that the HFS-induced increase of GABA levels was found 19 h after stimulation, it can be assumed that HFS has consequences lasting for several hours and which are functionally significant at a behavioral level, at least under our stimulation (frequency, timing, location, side and strength of stimulation) and testing conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

Role of zebrafish cytochrome P450 CYP1C genes in the reduced mesencephalic vein blood flow caused by activation of AHR2

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Kubota, Akira; Stegeman, John J.; Woodin, Bruce R.; Iwanaga, Toshihiko; Harano, Ryo; Peterson, Richard E.; Hiraga, Takeo; Teraoka, Hiroki

2011-01-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes various signs of toxicity in early life stages of vertebrates through activation of the aryl hydrocarbon receptor (AHR). We previously reported a sensitive and useful endpoint of TCDD developmental toxicity in zebrafish, namely a decrease in blood flow in the dorsal midbrain, but downstream genes involved in the effect are not known. The present study addressed the role of zebrafish cytochrome P450 1C (CYP1C) genes in association with a decrease in mesencephalic vein (MsV) blood flow. The CYP1C subfamily was recently discovered in fish and includes the paralogues CYP1C1 and CYP1C2, both of which are induced via AHR2 in zebrafish embryos. We used morpholino antisense oligonucleotides (MO or morpholino) to block initiation of translation of the target genes. TCDD-induced mRNA expression of CYP1Cs and a decrease in MsV blood flow were both blocked by gene knockdown of AHR2. Gene knockdown of CYP1C1 by two different morpholinos and CYP1C2 by two different morpholinos, but not by their 5 nucleotide-mismatch controls, was effective in blocking reduced MsV blood flow caused by TCDD. The same CYP1C-MOs prevented reduction of blood flow in the MsV caused by β-naphthoflavone (BNF), representing another class of AHR agonists. Whole-mount in situ hybridization revealed that mRNA expression of CYP1C1 and CYP1C2 was induced by TCDD most strongly in branchiogenic primordia and pectoral fin buds. In situ hybridization using head transverse sections showed that TCDD increased the expression of both CYP1Cs in endothelial cells of blood vessels, including the MsV. These results indicate a potential role of CYP1C1 and CYP1C2 in the local circulation failure induced by AHR2 activation in the dorsal midbrain of the zebrafish embryo. - Research Highlights: → We examine the roles of zebrafish CYP1C1 and CYP1C2 in TCDD developmental toxicity. → TCDD induces mRNA expression of both CYP1Cs in the mesencephalic vein. → Knockdown of each

Dorsal surgical stabilisation using tension bands for treatment of traumatic atlanto-occipital instability in a cat.

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Vedrine, B; Maurin, M P

2017-12-01

An atlanto-occipital instability secondary to a dog bite was diagnosed in a 4-year-old Persian cat. Dorsal stabilisation of the instability was made with two OrthoFiber prostheses (Securos), which were used as tension bands between the nuchal crests of the occipital bone and the spinous process of the axis. Total recovery was achieved 4 days after surgery. Normal alignment of the atlanto-occipital joint was observed on survey radiographs taken 6 weeks post-surgery. Although the right loop had failed, the alignment was still normal and no neurological after-effects could be identified. Dorsal divergent tension bands between the nuchal crests of the occipital bone and the spinous process of the axis can be used to stabilise traumatic atlanto-occipital instability. © 2017 Australian Veterinary Association.

Peripheral nerve injury fails to induce growth of lesioned ascending dorsal column axons into spinal cord scar tissue expressing the axon repellent Semaphorin3A

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Pasterkamp, R Jeroen; Anderson, Patrick N; Verhaagen, J

We have investigated the hypothesis that the chemorepellent Semaphorin3A may be involved in the failure of axonal regeneration after injury to the ascending dorsal columns of adult rats. Following transection of the thoracic dorsal columns, fibroblasts in the dorsolateral parts of the lesion site

Asymmetric development of dorsal and ventral attention networks in the human brain

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Kristafor Farrant

2015-04-01

Full Text Available Two neural systems for goal-directed and stimulus-driven attention have been described in the adult human brain; the dorsal attention network (DAN centered in the frontal eye fields (FEF and intraparietal sulcus (IPS, and the ventral attention network (VAN anchored in the temporoparietal junction (TPJ and ventral frontal cortex (VFC. Little is known regarding the processes governing typical development of these attention networks in the brain. Here we use resting state functional MRI data collected from thirty 7 to 12 year-old children and thirty 18 to 31 year-old adults to examine two key regions of interest from the dorsal and ventral attention networks. We found that for the DAN nodes (IPS and FEF, children showed greater functional connectivity with regions within the network compared with adults, whereas adults showed greater functional connectivity between the FEF and extra-network regions including the posterior cingulate cortex. For the VAN nodes (TPJ and VFC, adults showed greater functional connectivity with regions within the network compared with children. Children showed greater functional connectivity between VFC and nodes of the salience network. This asymmetric pattern of development of attention networks may be a neural signature of the shift from over-representation of bottom-up attention mechanisms to greater top-down attentional capacities with development.

Spinal dorsal horn astrocytes: New players in chronic itch

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Makoto Tsuda

2017-01-01

Full Text Available Chronic itch is a debilitating symptom of inflammatory skin conditions, such as atopic dermatitis, and systemic diseases, for which existing treatment is largely ineffective. Recent studies have revealed the selective neuronal pathways that are involved in itch sensations; however, the mechanisms by which itch turns into a pathological chronic state are poorly understood. Recent advances in our understanding of the mechanisms producing chronic itch have been made by defining causal roles for astrocytes in the spinal dorsal horn in mouse models of chronic itch including atopic dermatitis. Understanding the key roles of astrocytes may provide us with exciting insights into the mechanisms for itch chronicity and lead to a previously unrecognized target for treating chronic itch.

Bilateral axillary skin fold flaps used for dorsal thoracic skin wound closure in a dog : clinical communication

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B. G. Nevill

2010-05-01

Full Text Available A 10-year-old greyhound-cross dog was presented with a large, chronic skin wound extending over the interscapular region. The substantial skin defect was closed by making use of bilateral axillary skin fold flaps. It was possible to elevate the 2 skin flaps sufficiently to allow them to meet at the dorsal midline and thus facilitate complete closure of a large and awkwardly positioned wound. Small dorsal areas of the skin flaps underwent necrosis, but the resulting defects were closed without difficulty in a subsequent procedure. To the author's knowledge, this is the 1st clinical report of the use of bilateral axillary skin fold flaps in this fashion and describes an additional use of a versatile skin flap procedure.

Transcallosal connection patterns of opposite dorsal premotor regions support a lateralized specialization for action and perception

NARCIS (Netherlands)

van der Hoorn, Anouk; Potgieser, Adriaan R. E.; de Jong, Bauke M.

Lateralization of higher brain functions requires that a dominant hemisphere collects relevant information from both sides. The right dorsal premotor cortex (PMd), particularly implicated in visuomotor transformations, was hypothesized to be optimally located to converge visuospatial information

Plasticity of Select Primary Afferent Projections to the Dorsal Horn after a Lumbosacral Ventral Root Avulsion Injury and Root Replantation in Rats

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Allison J. Bigbee

2017-07-01

Full Text Available Injuries to the conus medullaris and cauda equina portions of the spinal cord result in neurological impairments, including paralysis, autonomic dysfunction, and pain. In experimental studies, earlier investigations have shown that a lumbosacral ventral root avulsion (VRA injury results in allodynia, which may be ameliorated by surgical replantation of the avulsed ventral roots. Here, we investigated the long-term effects of an L6 + S1 VRA injury on the plasticity of three populations of afferent projections to the dorsal horn in rats. At 8 weeks after a unilateral L6 + S1 VRA injury, quantitative morphological studies of the adjacent L5 dorsal horn showed reduced immunoreactivity (IR for the vesicular glutamate transporter, VGLUT1 and isolectin B4 (IB4 binding, whereas IR for calcitonin gene-related peptide (CGRP was unchanged. The IR for VGLUT1 and CGRP as well as IB4 binding was at control levels in the L5 dorsal horn at 8 weeks following an acute surgical replantation of the avulsed L6 + S1 ventral roots. Quantitative morphological studies of the L5 dorsal root ganglia (DRGs showed unchanged neuronal numbers for both the VRA and replanted series compared to shams. The portions of L5 DRG neurons expressing IR for VGLUT1 and CGRP, and IB4 binding were also the same between the VRA, replanted, and sham-operated groups. We conclude that the L5 dorsal horn shows selective plasticity for VGLUT1 and IB4 primary afferent projections after an L6 + S1 VRA injury and surgical repair.

New gene evolution in the bonus-TIF1-γ/TRIM33 family impacted the architecture of the vertebrate dorsal-ventral patterning network.

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Wisotzkey, Robert G; Quijano, Janine C; Stinchfield, Michael J; Newfeld, Stuart J

2014-09-01

Uncovering how a new gene acquires its function and understanding how the function of a new gene influences existing genetic networks are important topics in evolutionary biology. Here, we demonstrate nonconservation for the embryonic functions of Drosophila Bonus and its newest vertebrate relative TIF1-γ/TRIM33. We showed previously that TIF1-γ/TRIM33 functions as an ubiquitin ligase for the Smad4 signal transducer and antagonizes the Bone Morphogenetic Protein (BMP) signaling network underlying vertebrate dorsal-ventral axis formation. Here, we show that Bonus functions as an agonist of the Decapentaplegic (Dpp) signaling network underlying dorsal-ventral axis formation in flies. The absence of conservation for the roles of Bonus and TIF1-γ/TRIM33 reveals a shift in the dorsal-ventral patterning networks of flies and mice, systems that were previously considered wholly conserved. The shift occurred when the new gene TIF1-γ/TRIM33 replaced the function of the ubiquitin ligase Nedd4L in the lineage leading to vertebrates. Evidence of this replacement is our demonstration that Nedd4 performs the function of TIF1-γ/TRIM33 in flies during dorsal-ventral axis formation. The replacement allowed vertebrate Nedd4L to acquire novel functions as a ubiquitin ligase of vertebrate-specific Smad proteins. Overall our data reveal that the architecture of the Dpp/BMP dorsal-ventral patterning network continued to evolve in the vertebrate lineage, after separation from flies, via the incorporation of new genes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Estudo eletrofisiológico do nervo cutâneo dorsal lateral: aplicabilidade técnica e valores de referência

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DIAS, RAFAEL JOSÉ SOARES; CARNEIRO, ARMANDO PEREIRA

2000-01-01

O estudo da condução neural dos segmentos mais distais dos nervos mais longos pode ser capaz de reconhecer mais precocemente as alterações oriundas da maioria das polineuropatias. O objetivo deste estudo, foi verificar a aplicabilidade técnica do exame de condução ortodrômica do ramo cutâneo dorsal do nervo sural (nervo cutâneo dorsal lateral) em pessoas saudáveis, padronizar os valores normais para serem utilizados como referência e comparar seus valores com os do nervo sural na perna. Quare...

Neural correlates of stress and favorite-food cue exposure in adolescents: a functional magnetic resonance imaging study.

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Hommer, Rebecca E; Seo, Dongju; Lacadie, Cheryl M; Chaplin, Tara M; Mayes, Linda C; Sinha, Rajita; Potenza, Marc N

2013-10-01

Adolescence is a critical period of neurodevelopment for stress and appetitive processing, as well as a time of increased vulnerability to stress and engagement in risky behaviors. This study was conducted to examine brain activation patterns during stress and favorite-food-cue experiences relative to a neutral-relaxing condition in adolescents. Functional magnetic resonance imaging was employed using individualized script-driven guided imagery to compare brain responses with such experiences in 43 adolescents. Main effects of condition and gender were found, without a significant gender-by-condition interaction. Stress imagery, relative to neutral, was associated with activation in the caudate, thalamus, left hippocampus/parahippocampal gyrus, midbrain, left superior/middle temporal gyrus, and right posterior cerebellum. Appetitive imagery of favorite food was associated with caudate, thalamus, and midbrain activation compared with the neutral-relaxing condition. To understand neural correlates of anxiety and craving, subjective (self-reported) measures of stress-induced anxiety and favorite-food-cue-induced craving were correlated with brain activity during stress and appetitive food-cue conditions, respectively. High self-reported stress-induced anxiety was associated with hypoactivity in the striatum, thalamus, hippocampus, and midbrain. Self-reported favorite-food-cue-induced craving was associated with blunted activity in cortical-striatal regions, including the right dorsal and ventral striatum, medial prefrontal cortex, motor cortex, and left anterior cingulate cortex. These findings in adolescents indicate the activation of predominantly subcortical-striatal regions in the processing of stressful and appetitive experiences and link hypoactive striatal circuits to self-reported stress-induced anxiety and cue-induced favorite-food craving. Copyright © 2012 Wiley Periodicals, Inc.

Lag screw fixation of dorsal cortical stress fractures of the third metacarpal bone in 116 racehorses.

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Jalim, S L; McIlwraith, C W; Goodman, N L; Anderson, G A

2010-10-01

The effectiveness and best method to manage dorsal cortical stress fractures is not clear. This study was performed to evaluate the success of lag screw fixation of such fractures in a population of Thoroughbred racehorses. Lag screw fixation of dorsal cortical stress fractures is an effective surgical procedure allowing racehorses to return to their preoperative level of performance. The records of 116 racehorses (103 Thoroughbreds) admitted to Equine Medical Centre, California between 1986 and 2008 were assessed. Information obtained from medical records included subject details, limb(s) affected, fracture configuration, length of screw used in repair and presence of concurrent surgical procedures performed. Racing performance was evaluated relative to these factors using Fisher's exact test and nonparametric methods with a level of significance of Phorses, 83% raced preoperatively and 83% raced post operatively, with 63% having ≥5 starts. There was no statistically significant association between age, gender, limb affected, fracture configuration or presence of concurrent surgery and likelihood of racing post operatively or of having 5 or more starts. The mean earnings per start and the performance index for the 3 races following surgery were lower compared to the 3 races prior to surgery; however, 29 and 45% of horses either improved or did not change their earnings per start and performance index, respectively. Data show that lag screw fixation is successful at restoring ability to race in horses suffering from dorsal cortical stress fractures. © 2010 EVJ Ltd.

Transarticular facet screw stabilization and dorsal laminectomy in 26 dogs with degenerative lumbosacral stenosis with instability.

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Hankin, Elyshia J; Jerram, Richard M; Walker, Alexander M; King, Michael D; Warman, Christopher G A

2012-07-01

To describe outcome after transarticular facet screw stabilization and dorsal laminectomy for treatment of dynamic degenerative lumbosacral stenosis (DLS) in 26 dogs. Retrospective case series. Dogs (n = 26) with dynamic DLS. Medical records (2004-2009) of dogs treated with transarticular facet screw stabilization and dorsal laminectomy were reviewed. Dogs (n = 26) were available for immediate postoperative follow-up, 21 dogs at 6 weeks, and 15 at greater than 6 months. Dogs were evaluated by radiographic assessment and owner questionnaire. Lumbosacral (LS) intervertebral disc (IVD) spaces were measured on pre and postoperative 6-week and 6-month radiographs. In 23 dogs, improvement in clinical signs occurred within 7 days of surgery. Overall postsurgical complication rate directly related to the surgical procedure was 15.4%. LS IVD space measurements taken immediately postoperatively, at 6 weeks, and ≥ 6 months were all significantly increased compared with preoperative measurements. All working dogs (4) returned to full work within 14 months. Most owners (85%) reported their dog was ambulating normally at 6 months with no perceptible lameness during normal activity. All owners perceived their dog's ability to walk, run, and jump after surgery to be improved. Transarticular facet screw stabilization and dorsal laminectomy maintains distraction of the LS IVD space for medium-to-large breed dogs with dynamic DLS with a high degree of owner satisfaction, and is comparable to other reported surgical techniques for DLS. © Copyright 2012 by The American College of Veterinary Surgeons.

Epigenetic regulation of dorsal raphe GABA(B1a) associated with isolation-induced abnormal responses to social stimulation in mice.

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Araki, Ryota; Hiraki, Yosuke; Nishida, Shoji; Kuramoto, Nobuyuki; Matsumoto, Kinzo; Yabe, Takeshi

2016-02-01

In isolation-reared mice, social encounter stimulation induces locomotor hyperactivity and activation of the dorsal raphe nucleus (DRN), suggesting that dysregulation of dorsal raphe function may be involved in abnormal behaviors. In this study, we examined the involvement of dorsal raphe GABAergic dysregulation in the abnormal behaviors of isolation-reared mice. We also studied an epigenetic mechanism underlying abnormalities of the dorsal raphe GABAergic system. Both mRNA and protein levels of GABA(B1a), a GABA(B) receptor subunit, were increased in the DRN of isolation-reared mice, compared with these levels in group-reared mice. In contrast, mRNA levels for other GABAergic system-related genes (GABA(A) receptor α1, β2 and γ2 subunits, GABA(B) receptor 1b and 2 subunits, and glutamate decarboxylase 67 and 65) were unchanged. Intra-DRN microinjection of 0.06 nmol baclofen (a GABA(B) receptor agonist) exacerbated encounter-induced hyperactivity and aggressive behavior, while microinjection of 0.3 nmol phaclofen (a GABA(B) receptor antagonist) attenuated encounter-induced hyperactivity and aggressive behavior in isolation-reared mice. Furthermore, microinjection of 0.06 nmol baclofen elicited encounter-induced hyperactivity in group-reared mice. Neither baclofen nor phaclofen affected immobility time in the forced swim test and hyperactivity in a novel environment of isolation reared mice. Bisulfite sequence analyses revealed that the DNA methylation level of the CpG island around the transcription start site (TSS) of GABA(B1a) was decreased in the DRN of isolation-reared mice. Chromatin immunoprecipitation analysis showed that histone H3 was hyperacetylated around the TSS of GABA(B1a) in the DRN of isolation-reared mice. These findings indicate that an increase in dorsal raphe GABA(B1a) expression via epigenetic regulation is associated with abnormal responses to social stimulation such as encounter-induced hyperactivity and aggressive behavior in isolation

Anisomycin administered in the olfactory bulb and dorsal hippocampus impaired social recognition memory consolidation in different time-points.

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Pena, R R; Pereira-Caixeta, A R; Moraes, M F D; Pereira, G S

2014-10-01

To identify an individual as familiar, rodents form a specific type of memory named social recognition memory. The olfactory bulb (OB) is an important structure for social recognition memory, while the hippocampus recruitment is still controversial. The present study was designed to elucidate the OB and the dorsal hippocampus contribution to the consolidation of social memory. For that purpose, we tested the effect of anisomycin (ANI), which one of the effects is the inhibition of protein synthesis, on the consolidation of social recognition memory. Swiss adult mice with cannulae implanted into the CA1 region of the dorsal hippocampus or into the OB were exposed to a juvenile during 5 min (training session; TR), and once again 1.5 h or 24 h later to test social short-term memory (S-STM) or social long-term memory (S-LTM), respectively. To study S-LTM consolidation, mice received intra-OB or intra-CA1 infusion of saline or ANI immediately, 3, 6 or 18 h after TR. ANI impaired S-LTM consolidation in the OB, when administered immediately or 6h after TR. In the dorsal hippocampus, ANI was amnesic only if administered 3 h after TR. Furthermore, the infusion of ANI in either OB or CA1, immediately after training, did not affect S-STM. Moreover, ANI administered into the OB did not alter the animal's performance in the buried food-finding task. Altogether, our results suggest the consolidation of S-LTM requires both OB and hippocampus participation, although in different time points. This study may help shedding light on the specific roles of the OB and dorsal hippocampus in social recognition memory. Copyright © 2014 Elsevier Inc. All rights reserved.

Preferential loss of dorsal-hippocampus synapses underlies memory impairments provoked by short, multimodal stress.

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Maras, P M; Molet, J; Chen, Y; Rice, C; Ji, S G; Solodkin, A; Baram, T Z

2014-07-01

The cognitive effects of stress are profound, yet it is unknown if the consequences of concurrent multiple stresses on learning and memory differ from those of a single stress of equal intensity and duration. We compared the effects on hippocampus-dependent memory of concurrent, hours-long light, loud noise, jostling and restraint (multimodal stress) with those of restraint or of loud noise alone. We then examined if differences in memory impairment following these two stress types might derive from their differential impact on hippocampal synapses, distinguishing dorsal and ventral hippocampus. Mice exposed to hours-long restraint or loud noise were modestly or minimally impaired in novel object recognition, whereas similar-duration multimodal stress provoked severe deficits. Differences in memory were not explained by differences in plasma corticosterone levels or numbers of Fos-labeled neurons in stress-sensitive hypothalamic neurons. However, although synapses in hippocampal CA3 were impacted by both restraint and multimodal stress, multimodal stress alone reduced synapse numbers severely in dorsal CA1, a region crucial for hippocampus-dependent memory. Ventral CA1 synapses were not significantly affected by either stress modality. Probing the basis of the preferential loss of dorsal synapses after multimodal stress, we found differential patterns of neuronal activation by the two stress types. Cross-correlation matrices, reflecting functional connectivity among activated regions, demonstrated that multimodal stress reduced hippocampal correlations with septum and thalamus and increased correlations with amygdala and BST. Thus, despite similar effects on plasma corticosterone and on hypothalamic stress-sensitive cells, multimodal and restraint stress differ in their activation of brain networks and in their impact on hippocampal synapses. Both of these processes might contribute to amplified memory impairments following short, multimodal stress.

Preferential loss of dorsal-hippocampus synapses underlies memory impairments provoked by short, multimodal stress

Science.gov (United States)

Maras, P M; Molet, J; Chen, Y; Rice, C; Ji, S G; Solodkin, A; Baram, T Z

2014-01-01

The cognitive effects of stress are profound, yet it is unknown if the consequences of concurrent multiple stresses on learning and memory differ from those of a single stress of equal intensity and duration. We compared the effects on hippocampus-dependent memory of concurrent, hours-long light, loud noise, jostling and restraint (multimodal stress) with those of restraint or of loud noise alone. We then examined if differences in memory impairment following these two stress types might derive from their differential impact on hippocampal synapses, distinguishing dorsal and ventral hippocampus. Mice exposed to hours-long restraint or loud noise were modestly or minimally impaired in novel object recognition, whereas similar-duration multimodal stress provoked severe deficits. Differences in memory were not explained by differences in plasma corticosterone levels or numbers of Fos-labeled neurons in stress-sensitive hypothalamic neurons. However, although synapses in hippocampal CA3 were impacted by both restraint and multimodal stress, multimodal stress alone reduced synapse numbers severely in dorsal CA1, a region crucial for hippocampus-dependent memory. Ventral CA1 synapses were not significantly affected by either stress modality. Probing the basis of the preferential loss of dorsal synapses after multimodal stress, we found differential patterns of neuronal activation by the two stress types. Cross-correlation matrices, reflecting functional connectivity among activated regions, demonstrated that multimodal stress reduced hippocampal correlations with septum and thalamus and increased correlations with amygdala and BST. Thus, despite similar effects on plasma corticosterone and on hypothalamic stress-sensitive cells, multimodal and restraint stress differ in their activation of brain networks and in their impact on hippocampal synapses. Both of these processes might contribute to amplified memory impairments following short, multimodal stress. PMID:24589888

Radiological dorsal tilt analysis of AO type A, B, and C fractures of the distal radius treated conservatively or with extra-focal K-wire plus external fixateur

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Hoffmann, Michael [University Medical Center Hamburg-Eppendorf, Department of Trauma, Hand and Reconstructive Surgery, Hamburg (Germany); Borders General Hospital, Department for Trauma and Orthopaedic Surgery, Melrose, Roxburghshire, Scotland (United Kingdom); Schroeder, Malte; Gruber-Rathmann, Michaela; Ruecker, Andreas H. [University Medical Center Hamburg-Eppendorf, Department of Trauma, Hand and Reconstructive Surgery, Hamburg (Germany); Kossow, Kai [Department of Medical Psychology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany)

2012-09-15

Fractures of the distal radius are amongst the most common injury patterns. The dorsal tilt represents an important co-factor determining functional outcome. The purpose of this study was to analyze the radiological dorsal tilt and identify critical time frames in conservative and operative treatment of distal radius fractures. Eighty-seven conservatively treated (hematoma block assisted reduction and splinting) and 37 operatively treated (reduction, extra-focal K-wire fixation, bridging external fixateur) AO type A, B, and C fractures of the distal radius in 124 females were retrospectively analyzed. The dorsal tilt at the initial, post-reduction, and 2 weeks post-reduction stages was correlated with the final radiographic outcome at 6 weeks. Mean initial dorsal tilt was 16.53 in the conservatively treated group and 26.76 in the operatively treated group. Mean dorsal tilt after 6 weeks showed significant differences from the mean initial dorsal tilt at time of presentation within both groups (both groups p < 0.000). No significant differences between the two groups were found after 6 weeks of treatment (p = 0.194) regardless of the underlying AO fracture type. Conservatively treated radius fractures showed a significantly higher slip rate within the first 2 weeks (primary slip rate), whereas the operative group presented a significantly higher slip rate between the 2-week and 6-week radiographic checks (secondary slip rate). In terms of dorsal tilt, conservative (cast immobilization) and operative (K-wire fixation plus external fixateur) treatment demonstrated no significant differences at the final radiographic examination (6 weeks) regardless of the underlying AO fracture type. Both treatment groups showed treatment-associated different primary and secondary slip rates, indicating a need for more frequent radiographic checks within these critical time frames. (orig.)

A revision of Sanpasaurus yaoi Young, 1944 from the Early Jurassic of China, and its relevance to the early evolution of Sauropoda (Dinosauria

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Blair W. McPhee

2016-10-01

Full Text Available The Early Jurassic of China has long been recognized for its diverse array of sauropodomorph dinosaurs. However, the contribution of this record to our understanding of early sauropod evolution is complicated by a dearth of information on important transitional taxa. We present a revision of the poorly known taxon Sanpasaurus yaoi Young, 1944 from the late Early Jurassic Ziliujing Formation of Sichuan Province, southwest China. Initially described as the remains of an ornithopod ornithischian, we demonstrate that the material catalogued as IVPP V156 is unambiguously referable to Sauropoda. Although represented by multiple individuals of equivocal association, Sanpasaurus is nonetheless diagnosable with respect to an autapomorphic feature of the holotypic dorsal vertebral series. Additional material thought to be collected from the type locality is tentatively referred to Sanpasaurus. If correctly attributed, a second autapomorphy is present in a referred humerus. The presence of a dorsoventrally compressed pedal ungual in Sanpasaurus is of particular interest, with taxa possessing this typically ‘vulcanodontid’ character exhibiting a much broader geographic distribution than previously thought. Furthermore, the association of this trait with other features of Sanpasaurus that are broadly characteristic of basal eusauropods underscores the mosaic nature of the early sauropod–eusauropod transition. Our revision of Sanpasaurus has palaeobiogeographic implications for Early Jurassic sauropods, with evidence that the group maintained a cosmopolitan Pangaean distribution.

Osteology of Galeamopus pabsti sp. nov. (Sauropoda: Diplodocidae, with implications for neurocentral closure timing, and the cervico-dorsal transition in diplodocids

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Emanuel Tschopp

2017-05-01

Full Text Available Diplodocids are among the best known sauropod dinosaurs. Numerous specimens of currently 15 accepted species belonging to ten genera have been reported from the Late Jurassic to Early Cretaceous of North and South America, Europe, and Africa. The highest diversity is known from the Upper Jurassic Morrison Formation of the western United States: a recent review recognized 12 valid, named species, and possibly three additional, yet unnamed ones. One of these is herein described in detail and referred to the genus Galeamopus. The holotype specimen of Galeamopus pabsti sp. nov., SMA 0011, is represented by material from all body parts but the tail, and was found at the Howe-Scott Quarry in the northern Bighorn Basin in Wyoming, USA. Autapomorphic features of the new species include a horizontal canal on the maxilla that connects the posterior margin of the preantorbital and the ventral margin of the antorbital fenestrae, a vertical midline groove marking the sagittal nuchal crest, the presence of a large foramen connecting the postzygapophyseal centrodiapophyseal fossa and the spinopostzygapophyseal fossa of mid- and posterior cervical vertebrae, a very robust humerus, a laterally placed, rugose tubercle on the concave proximal portion of the anterior surface of the humerus, a relatively stout radius, the absence of a distinct ambiens process on the pubis, and a distinctly concave posteroventral margin of the ascending process of the astragalus. In addition to the holotype specimen SMA 0011, the skull USNM 2673 can also be referred to Galeamopus pabsti. Histology shows that the type specimen SMA 0011 is sexually mature, although neurocentral closure was not completed at the time of death. Because SMA 0011 has highly pneumatized cervical vertebrae, the development of the lamination appears a more important indicator for individual age than neurocentral fusion patterns. SMA 0011 is one of very few sauropod specimens that preserves the cervico-dorsal

Morphology of the dorsal lingual papillae in the newborn panther and Asian black bear.

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Emura, S; Hayakawa, D; Chen, H; Shoumura, S

2001-12-01

The dorsal lingual surfaces of a newborn panther (Panthera pardus) and two newborn asian black bears (Selenarctos thibetanus) were examined by scanning electron microscopy (SEM). The tongues of the panther and asian black bear were about 40 mm in length and about 20 mm in width. Filiform, fungiform and vallate papillae were found. The filiform papillae were distributed over the entire dorsal surface of the tongue. In the panther, the filiform papillae on margin of the lingual apex were divided into two shapes which were horny or club-shaped papillae. The filiform papillae on the midportion were larger than those on the lateral region in size. The fungiform papillae also were divided into two shapes which were hemispherical or club-shaped papillae. In the asian black bear, the filiform papillae on the margin of the lingual apex were larger than those on margin of the panther tongue. The vallate papillae in the animals of two species were located on both sides of the posterior end of the lingual body. Each papilla was surrounded by a groove and crescent pad.

Neural dynamics of event segmentation in music: converging evidence for dissociable ventral and dorsal networks.

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Sridharan, Devarajan; Levitin, Daniel J; Chafe, Chris H; Berger, Jonathan; Menon, Vinod

2007-08-02

The real world presents our sensory systems with a continuous stream of undifferentiated information. Segmentation of this stream at event boundaries is necessary for object identification and feature extraction. Here, we investigate the neural dynamics of event segmentation in entire musical symphonies under natural listening conditions. We isolated time-dependent sequences of brain responses in a 10 s window surrounding transitions between movements of symphonic works. A strikingly right-lateralized network of brain regions showed peak response during the movement transitions when, paradoxically, there was no physical stimulus. Model-dependent and model-free analysis techniques provided converging evidence for activity in two distinct functional networks at the movement transition: a ventral fronto-temporal network associated with detecting salient events, followed in time by a dorsal fronto-parietal network associated with maintaining attention and updating working memory. Our study provides direct experimental evidence for dissociable and causally linked ventral and dorsal networks during event segmentation of ecologically valid auditory stimuli.

[Hypervascularization syndrome of the penis following arterialization of the dorsal penile vein for erectile impotence].

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Fritsch, P; Grubauer, G; Hilty, N; Biedermann, H

1989-07-01

A hypervascularization syndrome following arterialization of the deep dorsal vein of the penis to amend venous erectile impotence is a rare cause of penile ulcers that has not previously been described in the dermatological literature. Arterialization is performed by installing a shunt from the inferior epigastric artery or a venous bypass from the femoral artery to the deep dorsal vein of the penis, resulting in a blockage of venous outflow and in retrograde inflow into the corpora cavernosa. Complications arise as a result of persistently elevated blood pressure in the deep venous system and the erectile tissue in 10-20% of cases and are most often linked to dilatation of the shunt: the consequences are enlargement and induration of the glans, hazard of phimosis and paraphimosis, pulsation of the penis, micturation difficulties and, ultimately, ulceration of the glans. Surgical reduction of the arterial inflow ("banding" of the shunt) is the only therapeutic procedure that reduces hypervascularization without compromising the newly gained erectile function.

MRI of enlarged dorsal ganglia, lumbar nerve roots, and cranial nerves in polyradiculoneuropathies

International Nuclear Information System (INIS)

Castillo, M.; Mukherji, S.K.

1996-01-01

This paper describes the MRI findings in four patients with a clinical diagnosis of hypertrophic polyradiculoneuropathies. In two examination of the lumbar spine showed enlarged nerve roots and dorsal ganglia, and similar findings were present in the cervical spine in a third. The cisternal portions of the cranial nerves were enlarged in another patient. MRI allows identification of enlarged nerves in hypertrophic polyradiculopathies. (orig.)

[Effectiveness of dorsal metacarpal island flap for treating scar contracture of finger web].

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Qian, Jun; Rui, Yongjun; Zhang, Quanrong; Xue, Mingyu; Zhang, Zhihai

2011-11-01

To investigate the effectiveness of dorsal metacarpal island flap for treating scar contracture of the finger web. Between June 2009 and December 2010, 10 patients with scar contracture of the finger web were treated. There were 6 males and 4 females with an average age of 30 years (range, 14-57 years). Scar contracture was caused by injury in 8 cases, by burn in 1 case, and by operation in 1 case. The locations were the 1st web space in 1 case, the 2nd web space in 3 cases, the 3rd web space in 5 cases, and the 4th web space in 1 case. The disease duration was 3 to 9 months with an average of 5 months. The maximum abduction was 10-20 degrees. After web space scar release, the dorsal metacarpal island flap (3.5 cm x 1.2 cm-4.0 cm x 2.0 cm in size) was used to reconstruct web space (2.0 cm x 1.0 cm-3.0 cm x 1.8 cm in size). The donor site was directly sutured or repaired with local flaps. At 2 days after operation, necrosis occurred in 1 flap, which healed by extractive treatment. The other flaps survived and wound healed by first intention; all the flaps at donor sites survived and incision healed by first intention. Ten patients were followed up 6 to 15 months (mean, 9 months). The reconstructed web space had good appearance, the maximum abduction was 80 degrees in 1 case of the 1st web space scars contracture, and the maximum abduction was 35-45 degrees (mean, 40 degrees) in the other 9 cases. In 8 scar patients causing by injury, no scar contracture recurred during follow-up. It can achieve good results in appearance and function to use dorsal metacarpal island flap for treating scar contracture of the finger web.

Ultrasonographic evidence of colonic mesenteric vessels as an indicator of right dorsal displacement of the large colon in 13 horses.

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Grenager, N S; Durham, M G

2011-08-01

This report describes the use of ultrasound to diagnose right dorsal displacement of the large colon (RDDLC) in 13 horses prior to surgery. Horses had ultrasonographic examinations performed of the right lateroventral aspect of the abdomen upon admission to the hospital with a 2-5 MHz broadband curvilinear sector scanning transducer after alcohol was used to wet the hair. First, the caecal vessels were identified in the right flank and followed medially and cranially. Next, each intercostal space, from caudal to cranial, was scanned from dorsal to ventral evaluating for abnormally-located mesenteric vessels associated with the large colon. Abnormally-located mesenteric vessels associated with the large colon, distinct from the caecal vessels, were identified in 13 of 23 horses with a diagnosis of RDDLC obtained at exploratory laparotomy. In horses, ultrasonographic visualisation of mesenteric vessels along the right lateral abdomen, dorsal to the costochondral junction in at least 2 intercostal spaces, distinct from the caecal vessels, is consistent with a surgical diagnosis of RDDLC. © 2011 EVJ Ltd.