Basal Ganglia Regions Research Articles

Cerebral infarction after mild head trauma in children

We conducted this retrospective, case record review to determine the risk factors and clinical features associated with cerebral infarction after mild head trauma in children. The median age of the cohort was 2.18 years (range, 6 mo-8 y). Most (26/29) of the patients developed the neurological symptoms and signs within 72 hours after trauma, 51.7% within 30 minutes. The first symptoms included hemiparesis (20), facial paresis (7), and convulsion (7). 86.21% of the lesions lay in basal ganglia region. Pre-existing basal ganglia calcification was identified in 13 as a risk factor.

Motor phenotype and magnetic resonance measures of basal ganglia iron levels in Parkinson's disease

BackgroundIn Parkinson's disease the degree of motor impairment can be classified with respect to tremor dominant and akinetic rigid features. While tremor dominance and akinetic rigidity might represent two ends of a continuum rather than discrete entities, it would be important to have non-invasive markers of any biological differences between them in vivo, to assess disease trajectories and response to treatment, as well as providing insights into the underlying mechanisms contributing to heterogeneity within the Parkinson's disease population. MethodsHere, we used magnetic resonance imaging to examine whether Parkinson's disease patients exhibit structural changes within the basal ganglia that might relate to motor phenotype. Specifically, we examined volumes of basal ganglia regions, as well as transverse relaxation rate (a putative marker of iron load) and magnetization transfer saturation (considered to index structural integrity) within these regions in 40 individuals. ResultsWe found decreased volume and reduced magnetization transfer within the substantia nigra in Parkinson's disease patients compared to healthy controls. Importantly, there was a positive correlation between tremulous motor phenotype and transverse relaxation rate (reflecting iron load) within the putamen, caudate and thalamus. ConclusionsOur findings suggest that akinetic rigid and tremor dominant symptoms of Parkinson's disease might be differentiated on the basis of the transverse relaxation rate within specific basal ganglia structures. Moreover, they suggest that iron load within the basal ganglia makes an important contribution to motor phenotype, a key prognostic indicator of disease progression in Parkinson's disease.

Non-dopaminergic Treatments for Motor Control in Parkinson’s Disease

The pathological processes underlying Parkinson's disease (PD) involve more than dopamine cell loss within the midbrain. These non-dopaminergic neurotransmitters include noradrenergic, serotonergic, glutamatergic, and cholinergic systems within cortical, brainstem and basal ganglia regions. Several non-dopaminergic treatments are now in clinical use to treat motor symptoms of PD, or are being evaluated as potential therapies. Agents for symptomatic monotherapy and as adjunct to dopaminergic therapies for motor symptoms include adenosine A2A antagonists and the mixed monoamine-B inhibitor (MAO-BI) and glutamate release agent safinamide. The largest area of potential use for non-dopaminergic drugs is as add-on therapy for motor fluctuations. Thus adenosine A2A antagonists, safinamide, and the antiepileptic agent zonisamide can extend the duration of action of levodopa. To reduce levodopa-induced dyskinesia, drugs that target overactive glutamatergic neurotransmission can be used, and include the non-selective N-methyl D-aspartate antagonist amantadine. More recently, selective metabotropic glutamate receptor (mGluR₅) antagonists are being evaluated in phase II randomized controlled trials. Serotonergic agents acting as 5-HT2A/2C antagonists, such as the atypical antipsychotic clozapine, may also reduce dyskinesia. 5-HT1A agonists theoretically can reduce dyskinesia, but in practice, may also worsen PD motor symptoms, and so clinical applicability has not yet been shown. Noradrenergic α2A antagonism using fipamezole can potentially reduce dyskinesia. Several non-dopaminergic agents have also been investigated to reduce non-levodopa-responsive motor symptoms such as gait and tremor. Thus the cholinesterase inhibitor donepezil showed mild benefit in gait, while the predominantly noradrenergic re-uptake inhibitor methylphenidate had conflicting results in advanced PD subjects. Tremor in PD may respond to muscarinic M4 cholinergic antagonists (anticholinergics), but tolerability is often poor. Alternatives include β-adrenergic antagonists such as propranolol. Other options include 5-HT2A antagonists, and drugs that have mixed binding properties involving serotonin and acetylcholine, such as clozapine and the antidepressant mirtazapine, can be effective in reducing PD tremor. Many other non-dopaminergic agents are in preclinical and phase I/II early stages of study, and the reader is directed to recent reviews. While levodopa remains the most effective agent to treat motor symptoms in PD, the overall approach to using non-dopaminergic drugs in PD is to reduce reliance on levodopa and to target non-levodopa-responsive symptoms.

Duplex color doppler evaluation of carotid atherosclerosis in patient with silent cerebral infarction detected by MRI

Background: Silent cerebral infarction (SCI) detected incidentally by MRI is considered the preliminary stage of accidental stroke and assumed to be secondary to atherosclerotic vascular disease (ASVD).The Duplex Color Doppler study is the initial screening non-invasive modality to identify carotid atherosclerotic changes and is the best approach for preoperative carotid artery evaluation in asymptomatic patients who can be expected to benefit of reduced risk of stroke in future. This cross- sectional study was carried out to assess the diagnostic usefulness of Duplex Color Doppler sonography in the evaluation of asymptomatic carotid atherosclerosis in prediction of silent cerebral infarction. Nature of extracranial carotid plaque and degree of luminal stenosis were compared & associated with MRI findings and risk factors of silent cerebral infarction. Method: This cross sectional study was carried out in the Radiology & Imaging Department of Dhaka Medical College Hospital during the period of July 2009 to June 2011 on 70 adult subjects of both sexes aged >50 years. Clinically suspected patients of silent cerebral infarction referred to Radiology & Imaging department of DMCH from OPD and Indoor Patient department underwent MRI of brain and among them those diagnosed as having Lacunar infarcts (Silent Cerebral Infarction) underwent Extra-cranial Carotid Duplex Color Doppler examination on both sides. Carotid lesions were evaluated by plaque score, maximum percent stenosis and the existence of ulcerated lesions. The relations between the carotid lesions and the incidence, size or localization of the brain lesions were investigated. Results: The incidence of SCI increases with age & more prevalent in male (P<0.05).Most SCI lesions were <1cm in size, single in number and is more prevalent in basal ganglia region (P<0.05) than subcortical white matter of right cerebral hemisphere (P<0.05) associated with ipsilateral high grade carotid stenosis & ulcerated plaque. The percentage of subjects with infarcts increased significantly as the plaque score increased (P<0.001) or subjects had high grade stenosis (P<0.001). The presence of pre-existing risk factors like HTN, DM, IHD, and Dyslipidaemia showed significant correlation with plaque score and SCI of brain. Conclusion: Both the severity and characteristics of asymptomatic carotid lesions estimated by Duplex color Doppler study were closely related to the appearance of silent infarcts.These results demonstrate that noninvasive assessment of carotid lesions can be useful in predicting the existence of silent cerebral infarction even in patients free from neurological deficits. DOI: http://dx.doi.org/10.3329/jdmc.v22i1.15599 J Dhaka Medical College, Vol. 22, No. 1, April, 2013, Page 19-25

Change Over Time in Brain Serotonin Transporter Binding in Major Depression: Effects of Therapy Measured with [123I]‐ADAM SPECT

Several studies have reported low brain serotonin transporter (SERT) binding in individuals with major depression. We hypothesized that the SERT standardized uptake ratio (SUR) values using [(123) I]-ADAM single photon emission computed tomography would increase in depressed subjects who responded to cognitive behavior therapy (CBT) compared to CBT nonresponders. [(123) I]-ADAM scans were acquired before and after 12 weeks of CBT from 20 depressed subjects and on two occasions 12 weeks apart from 10 nondepressed, healthy volunteers. The primary outcome measure was change over time in SUR values in the midbrain, medial temporal lobe, and basal ganglia regions. Depressed subjects demonstrated low pretreatment mean SUR values that significantly increased over time in the midbrain (P = .011), right medial temporal lobe (P = .008), and left medial temporal lobe (P = .000) regions. Treatment responders showed a significant increase over time in SUR values in left medial temporal lobe (P = .029) and right medial temporal lobe (P = .007) regions. Partial and nonresponder subjects also showed a significant increase over time in SUR values in the left medial temporal region (P = .040) (vs. healthy volunteers), but to a lesser degree. The findings suggest that low pretreatment SERT binding may increase over time in some depressed individuals who experience symptom improvement.

Evaluation of early cerebral metabolic, perfusion and microstructural changes in HCV-positive patients: A pilot study

The aim of the study was to evaluate early metabolic perfusion, and microstructural cerebral changes in patients with the hepatitis C virus (HCV) infection and normal appearing brain on plain MR using advanced MR techniques, as well as to assess correlations of MR measurements with the liver histology activity index (HAI). Fifteen HCV-positive patients and 18 control subjects underwent single voxel MR spectroscopy (MRS), perfusion weighted imaging (PWI), and diffusion tensor imaging (DTI), using a 1.5T MR unit. MRS metabolite ratios (NAA/Cr, Cho/Cr, mI/Cr) were calculated. PWI values of relative cerebral blood volume (rCBV) were assessed from 8 areas including several cortical locations, basal ganglia, and fronto-parietal white matter. DTI fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained from 14 white matter tracts. Compared to controls, HCV-positive patients showed significantly (p < 0.05) lower NAA/Cr ratios within frontal and parietal white matters, lower rCBV values within frontal and temporo-parietal cortices, decreased FA values, as well as increased ADC values in several white matter tracts. We also found elevated rCBV values in basal ganglia regions. The increase in mI/Cr and Cho/Cr ratio was correlated with a higher HAI score. The results of advanced MR techniques indicate neurotoxicity of HCV reflected by neuronal impairment within white matter, cortical hypoperfusion, and disintegrity within several white matter tracts. Hyperperfusion in basal ganglia may be an indicator of brain inflammation in HCV patients. Our findings may suggest a biologic link between HCV-related liver disease and cerebral dysfunction.

Altered Structure and Resting-State Functional Connectivity of the Basal Ganglia in Migraine Patients Without Aura

The aim of this study was to investigate the relevance of the basal ganglia (BG) in pathogenesis of migraine by assessing the abnormal volume and resting-state networks of the BG in migraine patients without aura (MWoA). The volume of the subsets in the BG was compared between 40 MWoA and 40 age- and gender-matched healthy controls. The resting-state functional connectivity of BG subsets with abnormal volume was also investigated. Reduced volume in the left caudate and the right nucleus accumbens (NAc) was detected in the migraine group compared with healthy controls; meanwhile, increased functional connectivity between the BG and several brain regions within nociceptive and somatosensory processing pathways was observed. Correlation analysis revealed significant correlations between the volume of the bilateral caudate and right NAc and disease duration. In addition, an increased monthly frequency of migraine attack was associated with increased functional connectivity between the bilateral caudate and left insula, and longer disease duration was correlated with increased functional connectivity between the right NAc and bilateral anterior cingulate cortex. Our results revealed abnormal volume of BG and dysfunctional dynamics during interictal resting state within pain pathways of the BG in MWoA, which validated the association between the BG and migraine. PerspectiveOur findings revealed the presence of reduced volume in NAc and caudate of the BG and interictal dysfunctional dynamics within BG networks in MWoA. The abnormal structure and function within the pain-related pathways of the BG were possibly associated with impaired pain processing and modulatory processes in MWoA.

Low apparent diffusion coefficient cluster-based analysis of diffusion-weighted MRI for prognostication of out-of-hospital cardiac arrest survivors

ObjectiveRecent studies suggested quantitative analysis of diffusion-weighted magnetic resonance imaging as a promising tool for early prognostication of cardiac arrest patients. However, most of their methods involve significant manual image handling often subjective and difficult to reproduce. Therefore developing a computerized analysis method using easy-to-define characteristics would be useful. MethodsComatose out-of-hospital cardiac arrest (OHCA) patients who underwent brain MRI between January 2008 and July 2012 were identified from an OHCA registry. Apparent diffusion coefficient (ADC) axial images were analyzed using a program to detect and characterize clusters of low ADC pixels from six brain regions including frontal, occipital, parietal, rolandic and temporal and basal ganglia region. Identified clusters were ranked according to size, mean ADC and minimum ADC to assess the regional maximum cluster size (MCS), lowest mean ADC (LMEAN) and lowest minimum ADC (LMIN). Their power to predict poor outcome, defined as 6-month CPC 3 or higher, was assessed by contingency table analyses. Results51 OHCA patients were eligible during the study period. The sensitivities of MCS, LMEAN and LMIN to detect poor outcome varied according to brain region from 62.5 to 90.0%, 50.0 to 72.5% and 42.5 to 82.5% with their specificities set to 100%, respectively. The MCS of occipital region showed most favorable test profile (sensitivity 90%, specificity 100%; AUROC 0.940, 95% confidence interval 0.874–1.000). ConclusionThe cluster-based computerized image analysis might be a simple but useful method for prediction of poor neurologic outcome. Future studies validating its prognostic performance are required.

Differential effects of insulin induced hypoglycaemia upon redox balance in distinct rat brain areas

Insulin induced hypoglycaemia does not generate uniform injuries throughout the brain. We hypothesized that redox balance in different brain regions might respond diversely to hypoglycaemia and aimed to test it in the rat brain model. Blood glucose level, malondialdehyde (MDA), protein carbonyl (PC) adducts and superoxide dismutase (Cu2+-Zn2+- SOD) activity in tissue homogenates of the cortex, cerebellum, basal ganglia and brain stem of rat brain (n = 12) were assayed 2 h after intraperitoneal administration of insulin in subcomatous dosage (6.0 IU/Kg diluted in normal saline) against matched controls (n = 8) that received the vehicle only (10 ml/kg). The cortex, cerebellum, basal ganglia and brain stem areas showed significantly higher mean values for MDA and PC products with lower mean Cu2+-Zn2+-SOD activity in the insulin administered hypoglycaemic rats (p < 0.001). Blood glucose level prevailed to be the chief predictor for the intracellular antioxidant status in all areas of the rat brain as evident from the multiple linear regression study. Post hoc ANOVA confirmed that oxidative stress markers were highest in the basal ganglia region compared to other brain areas (p < 0.001 for both MDA and PC products). Results indicated that hypoglycaemia induced impairment in redox balance were most damaging in the basal ganglia and least in the brain stem and cerebellum. We propose that similar mechanisms may contribute to distinctive neurological complications due to hypoglycaemia in human beings after receiving toxic dosage of insulin or intensive insulin therapy for a substantial period.

Brain Microbleeds: Distribution and Influence on Hematoma and Perihematomal Edema in Patients with Primary Intracerebral Hemorrhage

Brain microbleed is a marker of small vessel microhemorrhagic or microaneurysmal lesions, which may induce intracerebral hemorrhage (ICH). This study to prospectively evaluated the association between microbleeds, hematoma and perihematomal edema volume, and various clinical data, as well as patient outcome. Thirty-one patients with ICH and 31 healthy age-matched subjects were enrolled in our study. They were divided into two groups according to the presence or absence of microbleeds detected by MRI. Serial clinical and laboratory data were recorded. Modified Rankin Scale and Barthel Index were estimated three months after hemorrhage. The major location of microbleeds among patients with ICH was the basal ganglia. The volume of perihematomal edema was correlated with the initial hematoma volume on the first, fifth and seventh days after hemorrhage in patients with microbleeds. For patients without microbleeds, this correlation was also significant on the seventh day. Cerebral microbleeds in patients with ICH, especially in the basal ganglia region, represent micro-angiopathy, and are associated with leakage of blood and formation of perihemorrhage edema. Brain microbleeds found in patients with ICH warrant further investigation for evaluation of stroke risk.

Linking novelty seeking and harm avoidance personality traits to basal ganglia: volumetry and mean diffusivity

Novelty Seeking (NS) and Harm Avoidance (HA) temperamental traits are related to approaching or avoiding motivational circuits relying on the integrity and functionality of distributed brain areas implicated in arousal and action. The present study verified whether and how macro- and micro-structural variations of basal ganglia are correlated with scores obtained in the NS and HA temperamental scales of the Temperament and Character Inventory by Cloninger. To this aim, 125 healthy adults aged 18-67years of both sexes completed the Temperament and Character Inventory and underwent a high-resolution T1-weighted magnetic resonance imaging and a diffusion tensor imaging using a 3T scanner. The scores obtained in the temperamental scales were associated with volumes, mean diffusivity and fractional anisotropy measures of basal ganglia of both hemispheres separately, by using linear regression analyses. We found increased bilateral caudate and pallidum volumes associated with higher NS scores, as well as increased mean diffusivity in the bilateral putamen associated with higher HA scores. Macro- and micro-structural variations of basal ganglia regions contribute to explain the biological variance associated with NS or HA personality phenotype. The present findings evidencing some brain-temperament relationships highlight the importance of obtaining macro- and micro-structural measures in relation to individual differences.

Clinical Features and Risk Factors of Cerebral Infarction After Mild Head Trauma Under 18 Months of Age

Mild head trauma can cause cerebral infarction in children younger than 18 months of age, yet the pathogenesis, clinical characteristics, and risk factors are not fully understood. Data of 16 cases between August 2008 and September 2011, including clinical manifestations and imaging and laboratory findings were collected and analyzed. All patients had the history of mild head trauma. The median age of the cohort was 13.5 months (range 6 months to 18 months). All children developed neurologic symptoms and signs within 72 hours after trauma, 62.5% (10/16) within 30 minutes. The first symptoms included hemiparesis (9/16), facial paresis (4/16), and convulsion (6/16). Overall, 93.75% (15/16) of the lesions were in the basal ganglia region. Two risk factors were identified, basal ganglia calcification in 10 and cytomegalovirus infection in eight. After conservative therapy, the neurologic deficits recovered to some extent. Cerebral infarction after mild head trauma in children younger than 18 months of age may take place, especially under the circumstances of basal ganglia calcification or cytomegalovirus infection.

Disrupted cerebellar connectivity reduces whole‐brain network efficiency in multiple system atrophy

Multiple system atrophy of the cerebellar type is a sporadic neurodegenerative disorder of the central nervous system. We hypothesized that the white matter degeneration of the cerebellum and pons in this disease may cause a breakdown of cerebellar structural networks and further reduce the network efficiency of cerebellar-connected cerebral regions. Diffusion tensor tractography was used to construct the structural networks of 19 cerebellar-type multiple system atrophy patients, who were compared with 19 age- and sex-matched controls. Graph theory was used to assess the small-world properties and topological organization of structure networks in both the control and patient groups. Our results showed that the cerebellar-type multiple system atrophy patients exhibited altered small-world architecture with significantly increased characteristic shortest path lengths and decreased clustering coefficients. We also found that white matter degeneration in the cerebellum was characterized by reductions in network strength (number and integrity of fiber connections) of the cerebellar regions, which further induced extensively decreased network efficiency for numerous cerebral regions. Finally, we found that the reductions in nodal efficiency of the cerebellar lobules and bilateral sensorimotor, prefrontal, and basal ganglia regions negatively correlated with the severity of ataxia for the cerebellar-type multiple system atrophy patients. This study demonstrates for the first time that the brains of cerebellar-type multiple system atrophy patients exhibit disrupted topological organization of white matter structural networks. Thus, this study provides structural evidence of the relationship between abnormalities of white matter integrity and network efficiency that occurs in cerebellar-type multiple system atrophy.

Intrauterine grade IV intraventricular hemorrhage in a full-term infant leading to hydrocephalus

Peri/intraventricular hemorrhage (PIVH) is more often seen in premature neonates and can lead to posthemorrhagic hydrocephalus, characterized by high mortality rate and neurodevelopmental delay. We report a case of in utero PIVH in a full-term neonate, which led to hydrocephalus. The infant developed at 8months of gestational age intracerebral/intraventricular hemorrhage at the regions of the left basal ganglia and thalamus with significant intraventricular extension and ventriculomegaly, which was diagnosed with fetal MR scan, and progressed post partum to active multiloculated hydrocephalus. At the age of 3months, the infant was operated on with endoscopic fenestration of the ventricular septations at the left side and ventriculoperitoneal shunt insertion at the right side. A follow-up MR scan after 4months showed improvement of the ventriculomegaly and the multiloculated hydrocephalus. Up to a period of 6months follow up, there have been no shunt-related problems. The complications of a grade IV intraventricular hemorrhage are well documented in premature infants. It is difficult to know to what extent these apply equally to full-term infants with intraventricular hemorrhage. Ventricular hemorrhage is very rarely reported in full-term neonates, and even more rarely in the intrauterine period.

Impaired Prefrontal-Basal Ganglia Functional Connectivity and Substantia Nigra Hyperactivity in Schizophrenia

The theory that prefrontal cortex (PFC) dysfunction in schizophrenia leads to excess subcortical dopamine has generated widespread interest because it provides a parsimonious account for two core features of schizophrenia, cognitive deficits and psychosis, respectively. However, there has been limited empirical validation of this model. Moreover, the identity of the specific subcortical brain regions and circuits that may be impaired as a result of PFC dysfunction and mediate its link to psychosis in schizophrenia remains unclear. We undertook this event-related functional magnetic resonance imaging study to test the hypothesis that PFC dysfunction is associated with altered function of and connectivity with dopamine regulating regions of the basal ganglia. Eighteen individuals with schizophrenia or schizoaffective disorder and 19 healthy control participants completed event-related functional magnetic resonance imaging during working memory. We conducted between-group contrasts of task-evoked, univariate activation maps to identify regions of altered function in schizophrenia. We also compared the groups on the level of functional connectivity between a priori identified PFC and basal ganglia regions to determine if prefrontal disconnectivity in patients was present. We observed task-evoked hyperactivity of the substantia nigra that occurred in association with prefrontal and striatal hypoactivity in the schizophrenia group. The magnitude of prefrontal functional connectivity with these dysfunctional basal ganglia regions was decreased in the schizophrenia group. Additionally, the level of nigrostriatal functional connectivity predicted the level of psychosis. These results suggest that functional impairments of the prefrontal striatonigral circuit may be a common pathway linking the pathogenesis of cognitive deficits and psychosis in schizophrenia.

Developmental Venous Anomaly Associated with Hemi-Parkinson’s Syndrome

Objective and Importance: Developmental venous anomalies (DVAs) are common congenital anomalies of intracranial venous drainage. In general, it is felt that DVAs replace the normal venous drainage system and, unless associated with another lesion such as a cavernous malformation, should not produce symptoms. The present case raises important questions regarding the potential for DVAs to become symptomatic and the role of venous hypertension in this process. Clinical Presentation: We present the case of a 23-year-old woman who presented with rapidly progressive hemi-parkinsonism consisting of unilateral tremor, micrographia, gait difficulty, and cogwheel rigidity. MRI demonstrated a large DVA draining the region of the contralateral basal ganglia with associated high signal intensity on T2-weighted MR imaging and gadolinium enhancement. Arteriography demonstrated only the DVA with the trunk of the angioma draining forward toward the inferior petrosal sinus instead of into the deep venous system. A focal stricture of the main venous trunk was noted. Retrograde venography confirmed a tight stricture at the entrance of the venous trunk into the cavernous sinus. Conclusions: Although DVAs are generally considered benign variants of normal venous drainage, it is possible that in select cases, venous outflow restriction may result in symptomatic venous hypertension. This may be particularly problematic in the setting of a large DVA when multiple radicular veins drain into a single large venous channel.

The intrinsic and extrinsic connectome of subregions of the basal ganglia

Event Abstract Back to Event The intrinsic and extrinsic connectome of subregions of the basal ganglia Oliver Schmitt1*, Peter Eipert1, Konstanze Philipp1, Richard Kettlitz1 and Andreas Wree1 1 Department of Anatomy, Uni Rostock, Germany The motoric part of the basal ganglia (BG) network in the rat receives input from the primary motor cortex and consists of the caudate putamen complex, lateral and medial globus pallidus, substantia nigra, subthalamic nucleus and some thalamic nuclei (parafascicular, ventromedial, mediodorsal, ventrolateral, lateral habenula). Most of these classical components are directly (monosynaptically) interconnected. In a metastudy of 2200 tract-tracing publications of the rat central nervous system much more regions were found that are directly connected to functionally important regions of the motoric BG. In this contribution extrinsic and intrinsic connectivity of the BG has been analyzed. Using conventional global and local graph evaluation methods, new approaches of vulnerability and pathway analysis as well as techniques of visual analytics revealed new patterns of reciprocal connections. The unilateral intrinsic BG consists of 14 nodes which are connected by 122 edges resulting in a line density of 67.033% and an average cluster coefficient of 0.735. The average path length is 1.335. It was found that the accumbens nucleus has most ipsilateral and contralateral inputs while the lateral agranular prefrontal cortex has most ipsi- and contralateral outputs. The caudate putamen complex has the largest eigenvector centrality and the lowest Shapley rate. This indicates its importance for the intrinsic network structure of the BG. The substantia nigra pars compacta has a relative high rank with regard to vulnerability, however, the substantia nigra reticular part and the medial globus pallidus are more important to preserve network structure following removal of these nuclei. Keywords: computational neuroscience Conference: 5th INCF Congress of Neuroinformatics, Munich, Germany, 10 Sep - 12 Sep, 2012. Presentation Type: Poster Topic: Neuroinformatics Citation: Schmitt O, Eipert P, Philipp K, Kettlitz R and Wree A (2013). The intrinsic and extrinsic connectome of subregions of the basal ganglia. Front. Neuroinform. Conference Abstract: 5th INCF Congress of Neuroinformatics. doi: 10.3389/conf.fninf.2013.08.00016 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 21 Mar 2013; Published Online: 27 Nov 2013. * Correspondence: Dr. Oliver Schmitt, Department of Anatomy, Uni Rostock, Rostock, Germany, schmitt@med.uni-rostock.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Oliver Schmitt Peter Eipert Konstanze Philipp Richard Kettlitz Andreas Wree Google Oliver Schmitt Peter Eipert Konstanze Philipp Richard Kettlitz Andreas Wree Google Scholar Oliver Schmitt Peter Eipert Konstanze Philipp Richard Kettlitz Andreas Wree PubMed Oliver Schmitt Peter Eipert Konstanze Philipp Richard Kettlitz Andreas Wree Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Tracking the evolution of learning a novel dance sequence in expert ballet dancers

Last year we presented analysis on our project examining the neural networks involved in learning a new ballet to a novel piece of music over 8 months. We scanned dancers up to four times using fMRI along this time period. To date, we have now scanned 11 professional dancers from the National Ballet of Canada and twelve controls. All subjects visualized dancing to a one-minute piece of music during an 8 minute scan. Five epochs of one-minute of music from the ballet were alternated with 30-second fixation periods. Subjects were asked to visualize dancing their part while listening to the music. For more details of the training and performances see our IMRF abstract (DeSouza and Bar, 2012; DOI: 10.1163/187847612X646677). Results revealed a significant increase of BOLD signal, across the sessions in a network of brain regions including bilateral auditory cortex and supplementary motor cortex (SMA) over the first three imaging sessions, but a reduction in the fourth session at 34-weeks. This reduction in activity was not observed in basal ganglia (caudate nucleus). Our results suggest that as we learn a complex motor sequence in time to music, neuronal activity increases until 7 weeks and then decreases by 34-weeks, possibly a result of overlearning. Our findings may also highlight the unique role of basal ganglia regions in the learning of motor sequences. We now aim to use these functional regions of activation as seed regions to explore structural (DTI) and functional connectivity analysis.

Chronic alcohol abuse is implicated in the oxidative stress and the changes in the neurotrophic factor receptor expression in the human CNS

Alcohol abuse and alcoholism induce brain damage, and, in some cases, neurodegeneration. The pathogenesis of the alcohol-induced injury of the CNS is a complex process in which oxidative stress plays an essential role. Alcohol increases the formation of reactive oxygen species and affects the antioxidant defense system of the brain. It is well known that oxidative stress induces apoptosis in neurons, as well as in other cell types. Neurotropins and their receptors have a crucial role in neural regulation. The aim of this study is an overall analysis of the CNS neuronal and glial cell death and the oxidative status by the use of immunohistochemical methods. Three different CNS regions – cortical, subventricular and basal ganglia were analyzed in the autopsy samples obtained from 10 chronic alcohol abused patients. The immunohistochemical detection of oxidative damage was performed using anti-Cu/Zn SOD monoclonal antibody, neural activity – anti-NGFR (p75&lt;sup&gt;NTR&lt;/sup&gt;) antibody, apoptosis – the TUNEL reaction. Both, quantitative and semiquantitative estimations were used for the evaluation of results. The subventricular zone was characterized by a negative (75%) and a moderate (25%) astroglial SOD1 expression, the basal ganglia region – by strong (43%), moderate (43%), and low (14%) neuronal and moderate (71%) and low (29%) astroglial SOD1 expression, whereas, the cortex – by strong (33%) and moderate (66%) neuronal and moderate (67%), low (17%) and negative (17%) astroglial expression. The SOD1 expression was not detected in oligodendroglia and ependymocytes. Brain regions showed variability in the apoptotic cell death rates. Neuronal TUNEL-positive staining in basal ganglia was higher than in the cerebral cortex. TUNEL-positive astrocytes were detected in the white matter, more frequently in the basal ganglia region when compared to the cortex. The apoptosis marker was nearly absent in ependymal and oligodendroglial cells. The rate of TUNEL-positive cortex endothelial cells was detected at 7.9% level in the case of chronic alcohol abuse. Neuronal processes showed heterogeneous NGFR expression: in the cortex, basal ganglia and the subventricular zone (negative/low), whereas the subcortex and the white matter – moderate and moderate/strong, accordingly. Alcohol-induced CNS vulnerability is related to the increase in oxidative stress; furthermore, it suggests an increased risk of neurodegeneration for neuronal and glial cells.

Neural correlates of altered response inhibition and dysfunctional connectivity at rest in obsessive–compulsive disorder

Functional imaging studies of obsessive-compulsive disorder (OCD) have reported altered fronto-striatal activity during executive tasks. Additionally, altered connectivity of these regions during resting state was found. However, the relationship between brain activity during tasks and resting state remains poorly understood. The present study investigated neural correlates associated with abnormal response inhibition in OCD and to examine how resting state functional connectivity relates to task-related activity. Eighteen unmedicated adult OCD patients and 18 age- and sex-matched control subjects underwent functional magnetic resonance imaging scans during both resting state and a response inhibition task. Brain activation during response inhibition was compared between groups. Fronto-striatal regions showing altered task-related activity were used as seeds for connectivity analyses during resting state. During the response inhibition task, OCD patients had lower activation in areas including the cingulate cortex and basal ganglia regions. Compared with control subjects, patients with OCD showed increased functional connectivity of the caudate nucleus with the middle cingulate cortex and precentral gyrus during rest, suggesting hyperactive striatal-cortical connections. This study found altered function in fronto-striatal regions during response inhibition and its relation to resting state functional connectivity in OCD. Our results suggest that dysfunctional striatal-cortical connections even during rest may result in the failure of response inhibition and error monitoring observed in OCD patients.