These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

ARCHIVAL REPORT Basal Ganglia Shape Abnormalities in the Unaffected  

E-print Network

�11), and motor abnor- malities can occur in neuroleptic-na�ve schizophrenia patients (12). Basal ganglia of schizophrenia patients (25�27), but there have been relatively few studies of basal ganglia structureARCHIVAL REPORT Basal Ganglia Shape Abnormalities in the Unaffected Siblings of Schizophrenia

2

Basal Ganglia and Learning  

NSDL National Science Digital Library

The basal ganglia, a group of interconnected brain areas located deep in the cerebral cortex, have proved to be at work in learning, the formation of good and bad habits, and some psychiatric and addictive disorders.

2009-04-14

3

[Sensory input and basal ganglia].  

PubMed

Non-motor symptoms including sensory signs have recently been stressed in basal ganglia (BG) disorders. Why do sensory symptoms appear in BG disorders? Four closed loops have been shown between cortex and BG, but no sensory cortical-BG loops. I review two points: fiber connections between the somatosensory cortex and BG to explain sensory symptoms, and pain and basal ganglia. Somatosensory system and BG Many animal studies have shown somatosensory cortex- striatum- globus pallidus- motor thalamus connections, but no connections to the sensory thalamus. This indicates that sensory system may modulate four closed loops between the cortices and BG (motor loop, oculomotor loop, prefrontal loop and limbic loop) as an open loop system. Based on the above findings, two possible mechanisms may explain somatosensory symptoms in BG disorders. Motor modulation abnormalities may be considered as sensory symptoms in patients with BG disorders. Some sensory cognition abnormalities due to abnormal modulation of the prefrontal- BG loop may be considered as sensory symptoms. Pain and dopamine Two systems contribute to pain signs in patients with BG disorders. Descending pain modulation system: several brainstem nuclei send descending pain modulation fibers to the spinal cord mediated by serotonin or noradrenalin. These nuclei are facilitated by D2 neurons from the striatum. Striatal dopamine must suppress the pain information input at the spinal cord. Ascending pain relief system D2 neurons from the ventral tegmental area to anterior cingulate cortex, accumbens and amygdala may reduce pain feeling at the association cortices. In summary, dopamine system will reduce pain at the spinal cord and association cortices. Dopamine depletion, therefore, will enhance the pain sensation. PMID:23196445

Ugawa, Yoshikazu

2012-01-01

4

Functional Neuroanatomy of the Basal Ganglia  

PubMed Central

The basal ganglia refers to a group of subcortical nuclei responsible primarily for motor control, as well as other roles such as motor learning, executive functions and behaviors, and emotions. Proposed more than two decades ago, the classical basal ganglia model shows how information flows through the basal ganglia back to the cortex through two pathways with opposing effects for the proper execution of movement. Although much of the model has remained, the model has been modified and amplified with the emergence of new data. Furthermore, parallel circuits subserve the other functions of the basal ganglia engaging associative and limbic territories. Disruption of the basal ganglia network forms the basis for several movement disorders. This article provides a comprehensive account of basal ganglia functional anatomy and chemistry and the major pathophysiological changes underlying disorders of movement. We try to answer three key questions related to the basal ganglia, as follows: What are the basal ganglia? What are they made of? How do they work? Some insight on the canonical basal ganglia model is provided, together with a selection of paradoxes and some views over the horizon in the field. PMID:23071379

Lanciego, Jos L.; Luquin, Natasha; Obeso, Jos A.

2012-01-01

5

The expanding universe of disorders of the basal ganglia.  

PubMed

The basal ganglia were originally thought to be associated purely with motor control. However, dysfunction and pathology of different regions and circuits are now known to give rise to many clinical manifestations beyond the association of basal ganglia dysfunction with movement disorders. Moreover, disorders that were thought to be caused by dysfunction of the basal ganglia only, such as Parkinson's disease and Huntington's disease, have diverse abnormalities distributed not only in the brain but also in the peripheral and autonomic nervous systems; this knowledge poses new questions and challenges. We discuss advances and the unanswered questions, and ways in which progress might be made. PMID:24954674

Obeso, Jose A; Rodriguez-Oroz, Maria C; Stamelou, Maria; Bhatia, Kailash P; Burn, David J

2014-08-01

6

The cerebellum communicates with the basal ganglia  

Microsoft Academic Search

The cerebral cortex is interconnected with two major subcortical structures: the basal ganglia and the cerebellum. How and where cerebellar circuits interact with basal ganglia circuits has been a longstanding question. Using transneuronal transport of rabies virus in macaques, we found that a disynaptic pathway links an output stage of cerebellar processing, the dentate nucleus, with an input stage of

Eiji Hoshi; Lon Tremblay; Jean Fger; Peter L Carras; Peter L Strick

2005-01-01

7

Multiple Output Channels in the Basal Ganglia  

Microsoft Academic Search

The neural circuits that link the basal ganglia with the cerebral cortex are critically involved in the generation and control of voluntary movement. Retrograde transneuronal transport or herpes simplex virus type 1 was used to examine the organization of connections in the cebus monkey between an output nucleus of the basal ganglia, the internal segment of the globus pallidus (GPi),

John E. Hoover; Peter L. Strick

1993-01-01

8

Synaptic organisation of the basal ganglia  

PubMed Central

The basal ganglia are a group of subcortical nuclei involved in a variety of processes including motor, cognitive and mnemonic functions. One of their major roles is to integrate sensorimotor, associative and limbic information in the production of context-dependent behaviours. These roles are exemplified by the clinical manifestations of neurological disorders of the basal ganglia. Recent advances in many fields, including pharmacology, anatomy, physiology and pathophysiology have provided converging data that have led to unifying hypotheses concerning the functional organisation of the basal ganglia in health and disease. The major input to the basal ganglia is derived from the cerebral cortex. Virtually the whole of the cortical mantle projects in a topographic manner onto the striatum, this cortical information is processed within the striatum and passed via the so-called direct and indirect pathways to the output nuclei of the basal ganglia, the internal segment of the globus pallidus and the substantia nigra pars reticulata. The basal ganglia influence behaviour by the projections of these output nuclei to the thalamus and thence back to the cortex, or to subcortical premotor regions. Recent studies have demonstrated that the organisation of these pathways is more complex than previously suggested. Thus the cortical input to the basal ganglia, in addition to innervating the spiny projection neurons, also innervates GABA interneurons, which in turn provide a feed-forward inhibition of the spiny output neurons. Individual neurons of the globus pallidus innervate basal ganglia output nuclei as well as the subthalamic nucleus and substantia nigra pars compacta. About one quarter of them also innervate the striatum and are in a position to control the output of the striatum powerfully as they preferentially contact GABA interneurons. Neurons of the pallidal complex also provide an anatomical substrate, within the basal ganglia, for the synaptic integration of functionally diverse information derived from the cortex. It is concluded that the essential concept of the direct and indirect pathways of information flow through the basal ganglia remains intact but that the role of the indirect pathway is more complex than previously suggested and that neurons of the globus pallidus are in a position to control the activity of virtually the whole of the basal ganglia. PMID:10923985

BOLAM, J. P.; HANLEY, J. J.; BOOTH, P. A. C.; BEVAN, M. D.

2000-01-01

9

THE BASAL GANGLIA: FOCUSED SELECTION AND INHIBITION OF COMPETING MOTOR PROGRAMS  

Microsoft Academic Search

The basal ganglia comprise several nuclei in the forebrain, diencephalon, and midbrain thought to play a significant role in the control of posture and movement. It is well recognized that people with degenerative diseases of the basal ganglia suffer from rigidly held abnormal body postures, slowing of movement, involuntary movements, or a combination of these abnormalities. However, it has not

JONATHAN W MINK

1996-01-01

10

Functional anatomy of the basal ganglia. I. The cortico-basal ganglia-thalamo-cortical loop  

Microsoft Academic Search

This paper reviews some of the recent findings on different aspects of the anatomical organization of the basal ganglia. Attempts have been made to delineate the anatomical substrate of information processing along the cortico-basal ganglia-thalamo-cortical loop. Emphasis has been placed on data obtained with highly sensitive anterograde tract-tracing methods applied to the study of the main axis of the loop,

Andr Parent; Lili-Naz Hazrati

1995-01-01

11

Genetics Home Reference: Biotin-thiamine-responsive basal ganglia disease  

MedlinePLUS

... Reviews Clinical summary OMIM Genetic disorder catalog Conditions > Biotin-thiamine-responsive basal ganglia disease On this page: ... names Glossary definitions Reviewed January 2014 What is biotin-thiamine-responsive basal ganglia disease? Biotin-thiamine-responsive ...

12

368 Dispatch Basal ganglia: New therapeutic approaches to Parkinson's disease  

E-print Network

368 Dispatch Basal ganglia: New therapeutic approaches to Parkinson's disease Ann M. Graybiel As the search for molecular therapies for basal ganglia disorders, such as Parkinson's disease, accelerates, new-9822 The motor symptoms of basal ganglia disorders fall at two extremes. In Parkinson's disease and related

Graybiel, Ann M.

13

Dopamine release in the basal ganglia  

PubMed Central

Dopamine (DA) is a key transmitter in the basal ganglia, yet DA transmission does not conform to several aspects of the classic synaptic doctrine. Axonal DA release occurs through vesicular exocytosis and is action-potential and Ca2+ dependent. However, in addition to axonal release, DA neurons in midbrain exhibit somatodendritic release, by an incompletely understood, but apparently exocytotic mechanism. Even in striatum, axonal release sites are controversial, with evidence for DA varicosities that lack postsynaptic specialization, and largely extrasynaptic DA receptors and transporters. Moreover, DA release is often assumed to reflect a global response to a population of activities in midbrain DA neurons, whether tonic or phasic, with precise timing and specificity of action governed by other basal ganglia circuits. This view has been reinforced by anatomical evidence showing dense axonal DA arbors throughout striatum, and a lattice network formed by DA axons and glutamatergic input from cortex and thalamus. Nonetheless, localized DA transients are seen in vivo using voltammetric methods with high spatial and temporal resolution. Mechanistic studies using similar methods in vitro have revealed local regulation of DA release by other transmitters and modulators, as well as by proteins known to be disrupted in Parkinsons disease and other movement disorders. Notably, the actions of most other striatal transmitters on DA release also do not conform to the synaptic doctrine, with the absence of direct synaptic contacts for glutamate, GABA and aceylcholie (ACh) on striatal DA axons. Overall, the findings reviewed here indicate that DA signaling in the basal ganglia is sculpted by cooperation between the timing and pattern of DA input and those of local regulatory factors. PMID:21939738

Rice, Margaret E.; Patel, Jyoti C.; Cragg, Stephanie J.

2011-01-01

14

Basal ganglia and thalamic morphology in schizophrenia and bipolar disorder  

E-print Network

Basal ganglia and thalamic morphology in schizophrenia and bipolar disorder Fay Y. Womer a,n , Lei of the basal ganglia and thalamus in bipolar disorder (BP), schizophrenia-spectrum disorders (SCZ)], 32 SCZ-S individuals [28 with SCZ and 4 with schizoaffective disorder], and 27 HC using Free

15

Basal ganglia and cerebellar loops: motor and cognitive circuits  

Microsoft Academic Search

The traditional view that the basal ganglia and cerebellum are simply involved in the control of movement has been challenged in recent years. One of the pivotal reasons for this reappraisal has been new information about basal ganglia and cerebellar connections with the cerebral cortex. In essence, recent anatomical studies have revealed that these connections are organized into discrete circuits

Frank A Middleton; Peter L Strick

2000-01-01

16

Calcification of the basal ganglia following carbon monoxide poisoning  

Microsoft Academic Search

Minor calcification of the basal ganglia was demonstrated by computed tomography in a woman, aged 66, who had survived carbon monoxide poisoning 48 years earlier. Extensive neuropathological investigations have demonstrated calcified lesions of the basal ganglia in a number of conditions, but their frequency and topographic distribution in vivo remain to be elucidated, by means of CT.

F. Illum

1980-01-01

17

Sensory and cognitive functions of the basal ganglia  

Microsoft Academic Search

Recent studies have found that the basal ganglia are involved in diverse behavioral activities and suggest that they have executive functions. Highlights from the past year include anatomical and clinical studies that have used sophisticated, novel methods to confirm a role for the basal ganglia in somatosensory discrimination, visual perception, spatial working memory and habit learning.

Lucy L Brown; Jay S Schneider; Theodore I Lidsky

1997-01-01

18

Sensory and cognitive functions of the basal ganglia.  

PubMed

Recent studies have found that the basal ganglia are involved in diverse behavioral activities and suggest that they have executive functions. Highlights from the past year include anatomical and clinical studies that have used sophisticated, novel methods to confirm a role for the basal ganglia in somatosensory discrimination, visual perception, spatial working memory and habit learning. PMID:9142758

Brown, L L; Schneider, J S; Lidsky, T I

1997-04-01

19

Basal ganglia and thalamic morphology in schizophrenia and bipolar disorder.  

PubMed

In this study, we examined the morphology of the basal ganglia and thalamus in bipolar disorder (BP), schizophrenia-spectrum disorders (SCZ-S), and healthy controls (HC) with particular interest in differences related to the absence or presence of psychosis. Volumetric and shape analyses of the basal ganglia and thalamus were performed in 33 BP individuals [12 without history of psychotic features (NPBP) and 21 with history of psychotic features (PBP)], 32 SCZ-S individuals [28 with SCZ and 4 with schizoaffective disorder], and 27 HC using FreeSurfer-initiated large deformation diffeomorphic metric mapping. Significant volume differences were found in the caudate and globus pallidus, with volumes smallest in the NPBP group. Shape abnormalities showing inward deformation of superior regions of the caudate were observed in BP (and especially in NPBP) compared with HC. Shape differences were also found in the globus pallidus and putamen when comparing BP and SCZ-S groups. No significant differences were seen in the nucleus accumbens and thalamus. In summary, structural abnormalities in the caudate and globus pallidus are present in BP and SCZ-S. Differences were more apparent in the NPBP subgroup. The findings herein highlight the potential importance of separately examining BP subgroups in neuroimaging studies. PMID:24957866

Womer, Fay Y; Wang, Lei; Alpert, Kathryn I; Smith, Matthew J; Csernansky, John G; Barch, Deanna M; Mamah, Daniel

2014-08-30

20

Short latency cerebellar modulation of the basal ganglia.  

PubMed

The graceful, purposeful motion of our body is an engineering feat that remains unparalleled in robotic devices using advanced artificial intelligence. Much of the information required for complex movements is generated by the cerebellum and the basal ganglia in conjunction with the cortex. Cerebellum and basal ganglia have been thought to communicate with each other only through slow, multi-synaptic cortical loops, begging the question as to how they coordinate their outputs in real time. We found that the cerebellum rapidly modulates the activity of the striatum via a disynaptic pathway in mice. Under physiological conditions, this short latency pathway was capable of facilitating optimal motor control by allowing the basal ganglia to incorporate time-sensitive cerebellar information and by guiding the sign of cortico-striatal plasticity. Conversely, under pathological condition, this pathway relayed aberrant cerebellar activity to the basal ganglia to cause dystonia. PMID:25402853

Chen, Christopher H; Fremont, Rachel; Arteaga-Bracho, Eduardo E; Khodakhah, Kamran

2014-12-01

21

ANATOMY REVIEW: Basal Ganglia A group of subcortical nuclei  

E-print Network

;6 Cerebellar dysfunction · Review,Gross anatomy: Cerebellar nuclei · Information passes through these between1 ANATOMY REVIEW: Basal Ganglia · A group of subcortical nuclei · caudate, putamen, globus pallidus

Sergio, Lauren E.

22

Cognitive-motor interactions of the basal ganglia in development  

PubMed Central

Neural circuits linking activity in anatomically segregated populations of neurons in subcortical structures and the neocortex throughout the human brain regulate complex behaviors such as walking, talking, language comprehension, and other cognitive functions associated with frontal lobes. The basal ganglia, which regulate motor control, are also crucial elements in the circuits that confer human reasoning and adaptive function. The basal ganglia are key elements in the control of reward-based learning, sequencing, discrete elements that constitute a complete motor act, and cognitive function. Imaging studies of intact human subjects and electrophysiologic and tracer studies of the brains and behavior of other species confirm these findings. We know that the relation between the basal ganglia and the cerebral cortical region allows for connections organized into discrete circuits. Rather than serving as a means for widespread cortical areas to gain access to the motor system, these loops reciprocally interconnect a large and diverse set of cerebral cortical areas with the basal ganglia. Neuronal activity within the basal ganglia associated with motor areas of the cerebral cortex is highly correlated with parameters of movement. Neuronal activity within the basal ganglia and cerebellar loops associated with the prefrontal cortex is related to the aspects of cognitive function. Thus, individual loops appear to be involved in distinct behavioral functions. Damage to the basal ganglia of circuits with motor areas of the cortex leads to motor symptoms, whereas damage to the subcortical components of circuits with non-motor areas of the cortex causes higher-order deficits. In this report, we review some of the anatomic, physiologic, and behavioral findings that have contributed to a reappraisal of function concerning the basal ganglia and cerebellar loops with the cerebral cortex and apply it in clinical applications to attention deficit/hyperactivity disorder (ADHD) with biomechanics and a discussion of retention of primitive reflexes being highly associated with the condition. PMID:24592214

Leisman, Gerry; Braun-Benjamin, Orit; Melillo, Robert

2014-01-01

23

Cognitive impairment and dementia in basal ganglia disorders  

Microsoft Academic Search

We present an update focusing on research from the past 2 years on cognitive impairment and dementia in basal ganglia disorders,\\u000a including Huntingtons disease, progressive supranuclear palsy, Parkinsons disease, Parkinsons disease dementia, and dementia\\u000a with Lewy bodies. In addition to the many recent papers that aim to refine descriptions of the cognitive phenotypes in the\\u000a basal ganglia disorders, the current

Julie C. Stout; Shannon A. Johnson

2005-01-01

24

Basal ganglia activity patterns in parkinsonism and computational modeling of their downstream effects  

PubMed Central

The availability of suitable animal models and of the opportunity to record electrophysiologic data in movement disorder patients undergoing neurosurgical procedures has allowed researchers to investigate parkinsonism-related changes in neuronal firing patterns in the basal ganglia and associated areas of thalamus and cortex. These studies have shown that parkinsonism is associated with increased activity in the basal ganglia output nuclei, along with an increase in burst discharges, oscillatory firing, and synchronous firing patterns throughout the basal ganglia. Computational approaches have the potential to play an important role in the interpretation of these data. Such efforts can provide a formalized view of neuronal interactions in the network of connections between basal ganglia, thalamus and cortex, allow for the exploration of possible contributions of particular network components to parkinsonism, and potentially result in new conceptual frameworks and hypotheses that can be subjected to biological testing. It has proven very difficult, however, to integrate the wealth of the experimental findings into coherent models of the disease. In this review, we provide an overview of the abnormalities in neuronal activity that have been associated with parkinsonism. Subsequently, we discuss some particular efforts to model the pathophysiologic mechanisms that may link abnormal basal ganglia activity to the cardinal parkinsonian motor signs and may help explain the mechanisms underlying the therapeutic efficacy of deep brain stimulation for Parkinsons disease. We emphasize the logical structure of these computational studies, making clear the assumptions from which they proceed and the consequences and predictions that follow from these assumptions. PMID:22805066

Rubin, Jonathan E.; McIntyre, Cameron C.; Turner, Robert S.; Wichmann, Thomas

2012-01-01

25

The basal ganglias contributions to perceptual decision-making  

PubMed Central

Perceptual decision-making is a computationally demanding process that requires the brain to interpret incoming sensory information in the context of goals, expectations, preferences, and other factors. These integrative processes engage much of cortex but also require contributions from subcortical structures to affect behavior. Here we summarize recent evidence supporting specific computational roles of the basal ganglia in perceptual decision-making. These roles likely share common mechanisms with the basal ganglias other, more well-established functions in motor control, learning, and other aspects of cognition and thus can provide insights into the general roles of this important subcortical network in higher brain function. PMID:23972593

Ding, Long; Gold, Joshua I.

2013-01-01

26

CODING OF BEHAVIORAL SEQUENCES IN THE BASAL GANGLIA  

E-print Network

and thoughts of obsessive-compulsive disorder,8 both of which are associated with pathology of the basal disorders of the basal ganglia strongly supports a motor function. However, close scrutiny suggests is disturbed by this disorder. Huntington's patients also have deficits in related high-level "ideomotor

Berridge, Kent

27

CODING OF BEHAVIORAL SEQUENCES IN THE BASAL GANGLIA  

E-print Network

and thoughts of obsessive-compulsive disorder8 , both of which are associated with pathology of the basal disorders of the basal ganglia strongly supports a motor function. However, close scrutiny suggests is disturbed by this disorder. Huntington's patients also have deficits in related high-level "ideomotor

Berridge, Kent

28

Altered functional connectivity of basal ganglia circuitry in dental phobia.  

PubMed

Recent symptom provocation studies that compared patients suffering from dental phobia with healthy controls identified hyperactivation of basal ganglia structures, but none have assessed striatal functional connectivity. We reanalyzed data from a previous functional magnetic resonance imaging study on dental phobia. Patients (20 men, 25 women) and healthy controls (18 men, 23 women) had been exposed to pictures showing dental treatment, and neutral contents. We conducted connectivity analyses via psychophysiological interactions (PPIs). Relative to non-phobic controls, the patients showed decreased connectivity between prefrontal and basal ganglia regions. Moreover, the clinical group was characterized by increased internal basal ganglia connectivity, which was more pronounced in female compared with male patients. This study provides first evidence for an altered information flow within a fronto-striatal network in dentophobic individuals during visual symptom provocation, which can be considered a neuromarker of this disorder. PMID:24084590

Scharmller, Wilfried; Leutgeb, Verena; Schnganer, Florian; Hermann, Andrea; Stark, Rudolf; Schienle, Anne

2014-10-01

29

A Critical Review of Habit Learning and the Basal Ganglia  

PubMed Central

The current paper briefly outlines the historical development of the concept of habit learning and discusses its relationship to the basal ganglia. Habit learning has been studied in many different fields of neuroscience using different species, tasks, and methodologies, and as a result it has taken on a wide range of definitions from these various perspectives. We identify five common but not universal, definitional features of habit learning: that it is inflexible, slow or incremental, unconscious, automatic, and insensitive to reinforcer devaluation. We critically evaluate for each of these how it has been defined, its utility for research in both humans and non-human animals, and the evidence that it serves as an accurate description of basal ganglia function. In conclusion, we propose a multi-faceted approach to habit learning and its relationship to the basal ganglia, emphasizing the need for formal definitions that will provide directions for future research. PMID:21909324

Seger, Carol A.; Spiering, Brian J.

2011-01-01

30

The basal ganglia's contributions to perceptual decision making.  

PubMed

Perceptual decision making is a computationally demanding process that requires the brain to interpret incoming sensory information in the context of goals, expectations, preferences, and other factors. These integrative processes engage much of cortex but also require contributions from subcortical structures to affect behavior. Here we summarize recent evidence supporting specific computational roles of the basal ganglia in perceptual decision making. These roles probably share common mechanisms with the basal ganglia's other, more well-established functions in motor control, learning, and other aspects of cognition and thus can provide insights into the general roles of this important subcortical network in higher brain function. PMID:23972593

Ding, Long; Gold, Joshua I

2013-08-21

31

Multidimensional Sequence Learning in Patients with Focal Basal Ganglia Lesions  

ERIC Educational Resources Information Center

Parkinson's patients have been found to be impaired in learning movement sequences. In the current study, patients with unilateral basal ganglia lesions due to stroke were tested on a serial reaction time task in which responses were based on the spatial location of each stimulus. The spatial locations either followed a fixed sequence or were

Shin, J.C.; Aparicio, P.; Ivry, R.B.

2005-01-01

32

Mephedrone alters basal ganglia and limbic neurotensin systems.  

PubMed

Mephedrone (4-methylmethcathinone) is a synthetic cathinone designer drug that alters pre-synaptic dopamine (DA) activity like many psychostimulants. However, little is known about the post-synaptic dopaminergic impacts of mephedrone. The neuropeptide neurotensin (NT) provides inhibitory feedback for basal ganglia and limbic DA pathways, and post-synaptic D1 -like and D2 -like receptor activity affects NT tissue levels. This study evaluated how mephedrone alters basal ganglia and limbic system NT content and the role of NT receptor activation in drug consumption behavior. Four 25 mg/kg injections of mephedrone increased NT content in basal ganglia (striatum, substantia nigra and globus pallidus) and the limbic regions (nucleus accumbens core), while a lower dosage (5 mg/kg/injection) only increased striatal NT content. Mephedrone-induced increases in basal ganglia NT levels were mediated by D1 -like receptors in the striatum and the substantia nigra by both D1 -like and D2 -like receptors in the globus pallidus. Mephedrone increased substance P content, another neuropeptide, in the globus pallidus, but not in the dorsal striatum or substantia nigra. Finally, the NT receptor agonist PD149163 blocked mephedrone self-administration, suggesting reduced NT release, as indicated by increased tissue levels, likely contributing to patterns of mephedrone consumption. PMID:24678634

German, Christopher L; Hoonakker, Amanda H; Fleckenstein, Annette E; Hanson, Glen R

2014-08-01

33

The role of basal ganglia-forebrain circuitry in the vocal learning of songbirds  

E-print Network

The basal ganglia form the largest sub-cortical structure in the human brain and are implicated in numerous human diseases. In songbirds, as in mammals, basal ganglia-forebrain circuits are necessary for the learning and ...

Andalman, Aaron Samuel

2009-01-01

34

A cortical motor nucleus drives the basal ganglia-recipient thalamus in singing birds  

E-print Network

The pallido-recipient thalamus transmits information from the basal ganglia to the cortex and is critical for motor initiation and learning. Thalamic activity is strongly inhibited by pallidal inputs from the basal ganglia, ...

Goldberg, Jesse H.

35

Basal ganglia function, stuttering, sequencing, and repair in adult songbirds.  

PubMed

A pallial-basal-ganglia-thalamic-pallial loop in songbirds is involved in vocal motor learning. Damage to its basal ganglia part, Area X, in adult zebra finches has been noted to have no strong effects on song and its function is unclear. Here we report that neurotoxic damage to adult Area X induced changes in singing tempo and global syllable sequencing in all animals, and considerably increased syllable repetition in birds whose song motifs ended with minor repetitions before lesioning. This stuttering-like behavior started at one month, and improved over six months. Unexpectedly, the lesioned region showed considerable recovery, including immigration of newly generated or repaired neurons that became active during singing. The timing of the recovery and stuttering suggest that immature recovering activity of the circuit might be associated with stuttering. These findings indicate that even after juvenile learning is complete, the adult striatum plays a role in higher level organization of learned vocalizations. PMID:25307086

Kubikova, Lubica; Bosikova, Eva; Cvikova, Martina; Lukacova, Kristina; Scharff, Constance; Jarvis, Erich D

2014-01-01

36

Basal ganglia function, stuttering, sequencing, and repair in adult songbirds  

PubMed Central

A pallial-basal-ganglia-thalamic-pallial loop in songbirds is involved in vocal motor learning. Damage to its basal ganglia part, Area X, in adult zebra finches has been noted to have no strong effects on song and its function is unclear. Here we report that neurotoxic damage to adult Area X induced changes in singing tempo and global syllable sequencing in all animals, and considerably increased syllable repetition in birds whose song motifs ended with minor repetitions before lesioning. This stuttering-like behavior started at one month, and improved over six months. Unexpectedly, the lesioned region showed considerable recovery, including immigration of newly generated or repaired neurons that became active during singing. The timing of the recovery and stuttering suggest that immature recovering activity of the circuit might be associated with stuttering. These findings indicate that even after juvenile learning is complete, the adult striatum plays a role in higher level organization of learned vocalizations. PMID:25307086

Kubikova, Lubica; Bosikova, Eva; Cvikova, Martina; Lukacova, Kristina; Scharff, Constance; Jarvis, Erich D.

2014-01-01

37

Cerebellar networks with the cerebral cortex and basal ganglia  

PubMed Central

The dominant view of cerebellar function has been that it is exclusively concerned with motor control and coordination. Recent results from neuroanatomical, behavioral and imaging studies have profoundly changed this view. Neuroanatomical studies using virus transneuronal tracers have demonstrated that the output from the cerebellum reaches vast areas of the neocortex, including regions of prefrontal and posterior parietal cortex. Furthermore, it has recently become clear that the cerebellum is reciprocally connected with the basal ganglia, indicating that the two subcortical structures are part of a densely interconnected network. Altogether, these results provide the neuroanatomical substrate for cerebellar involvement in non-motor functions mediated by the prefrontal and posterior parietal cortex, as well as in processes traditionally associated with the basal ganglia. PMID:23579055

Bostan, Andreea C.; Dum, Richard P.; Strick, Peter L.

2013-01-01

38

Focal Hand Dystonia Secondary to Basal Ganglia Germinoma  

PubMed Central

Descriptions of symptomatic focal dystonia caused by focal lesions of the central nervous system (CNS) are rare in the literature. We report a 9-year-old child who experienced sudden-onset left-hand dystonia for 6 months. Brain magnetic resonance imaging showed a mass lesion involving the putamen, globus pallidus, head of caudate, and the anterior limb of the internal capsule. Histopathological and immunocytochemical examinations of the mass revealed features characteristic of malignant germinoma. CNS germinoma in the basal ganglia is very rare. Combining previous reports in the literature with the anatomical and clinical presentation of our case suggests that this phenomenon results from disruption of the pathways within and adjacent to the basal ganglia. PMID:19513283

Kim, Joong-Seok; Han, Soo-Jeong; Kim, Woojun; Kim, Bum-Soo; Kim, Yeong-In

2007-01-01

39

Centrality of striatal cholinergic transmission in Basal Ganglia function.  

PubMed

Work over the past two decades revealed a previously unexpected role for striatal cholinergic interneurons in the context of basal ganglia function. The recognition that these interneurons are essential in synaptic plasticity and motor learning represents a significant step ahead in deciphering how the striatum processes cortical inputs, and why pathological circumstances cause motor dysfunction. Loss of the reciprocal modulation between dopaminergic inputs and the intrinsic cholinergic innervation within the striatum appears to be the trigger for pathophysiological changes occurring in basal ganglia disorders. Accordingly, there is now compelling evidence showing profound changes in cholinergic markers in these disorders, in particular Parkinson's disease and dystonia. Based on converging experimental and clinical evidence, we provide an overview of the role of striatal cholinergic transmission in physiological and pathological conditions, in the context of the pathogenesis of movement disorders. PMID:21344017

Bonsi, Paola; Cuomo, Dario; Martella, Giuseppina; Madeo, Graziella; Schirinzi, Tommaso; Puglisi, Francesca; Ponterio, Giulia; Pisani, Antonio

2011-01-01

40

Proactive Selective Response Suppression Is Implemented via the Basal Ganglia  

PubMed Central

In the welter of everyday life, people can stop particular response tendencies without affecting others. A key requirement for such selective suppression is that subjects know in advance which responses need stopping. We hypothesized that proactively setting up and implementing selective suppression relies on the basal ganglia and, specifically, regions consistent with the inhibitory indirect pathway for which there is scant functional evidence in humans. Consistent with this hypothesis, we show, first, that the degree of proactive motor suppression when preparing to stop selectively (indexed by transcranial magnetic stimulation) corresponds to striatal, pallidal, and frontal activation (indexed by functional MRI). Second, we demonstrate that greater striatal activation at the time of selective stopping correlates with greater behavioral selectivity. Third, we show that people with striatal and pallidal volume reductions (those with premanifest Huntington's disease) have both absent proactive motor suppression and impaired behavioral selectivity when stopping. Thus, stopping goals are used to proactively set up specific basal ganglia channels that may then be triggered to implement selective suppression. By linking this suppression to the striatum and pallidum, these results provide compelling functional evidence in humans of the basal ganglia's inhibitory indirect pathway. PMID:23946385

Majid, D. S. Adnan; Cai, Weidong; Corey-Bloom, Jody

2013-01-01

41

Modulation of the basal ganglia dopaminergic system in a transgenic mouse exhibiting dystonia-like features  

PubMed Central

Dystonia is a movement disorder characterized by involuntary excessive muscle activity and abnormal postures. There are data supporting the hypothesis that basal ganglia dysfunction, and specifically dopaminergic system dysfunction, plays a role in dystonia. In the present study, we used hyperkinetic transgenic mice generated as a model of DYT1 dystonia and compared the basal ganglia dopaminergic system between transgenic mice exhibiting hyperkinesia (affected) transgenic mice not showing movement abnormalities (unaffected), and non-transgenic littermates A decrease in the density of striatal D2 binding sites, measured by [3H]raclopride binding, and D2 mRNA expression in substantia nigra pars compacta (SNpc) was revealed in affected an unaffected transgenic mice when compared with non-transgenic. No difference in D1 receptor binding and DAT binding, measured by [3H]SCH23390 and [3H]WIN35428 binding, respectively, was found in striatum of transgenic animals. In SNpc, increased levels of DAT binding sites were observed in affected and unaffected animals compared to non-transgenic, whereas no change in DAT mRNA expression was found. Our results show selective neurochemical changes in the basal ganglia dopaminergic system, suggesting a possible involvement in the pathophysiology of dystonialike motor hyperactivity. PMID:21136125

Giannakopoulou, D.; Armata, I. A.; Mitsacos, A.; Shashidharan, P.; Giompres, P.

2011-01-01

42

Asymptomatic moyamoya syndrome, atlantoaxial subluxation and basal ganglia calcification in a child with Down syndrome  

PubMed Central

Down syndrome, the most common chromosomal abnormality, may be associated with various neurologic complications such as moyamoya syndrome, cervical spinal cord compression due to atlantoaxial subluxation, and basal ganglia damage, as well as epileptic seizures and stroke. Many cases of Down syndrome accompanied by isolated neurologic manifestations have been reported in children; however, Down syndrome with multiple neurologic conditions is rare. Here, we have reported a case of Down syndrome in a 10-year-old girl who presented with asymptomatic moyamoya syndrome, atlantoaxial subluxation with spinal cord compression, and basal ganglia calcification. To the best of our knowledge, this is the first report of Down syndrome, in a child, which was accompanied by these 3 neurologic complications simultaneously. As seen in this case, patients with Down syndrome may have neurologic conditions without any obvious neurologic symptoms; hence, patients with Down syndrome should be carefully examined for the presence of neurologic conditions. PMID:24416050

Lee, Kun-Soo; Weon, Young Cheol

2013-01-01

43

A syndrome of bilateral symmetrical basal ganglia lesions in diabetic dialysis patients.  

PubMed

A rare syndrome of acute symmetrical bilateral basal ganglia lesions in diabetic dialysis patients that manifests clinically with headache, dysarthria, and gait and movement disorder has been described almost exclusively in patients of Asian descent. The pathophysiology of this condition has not been established. Of the 28 cases reported, 3 patients have been from North America. In the context of magnetic resonance imaging showing dramatic resolution of lesions of the basal ganglia, this report describes a fourth case from North America of a 47-year-old Hispanic woman with diabetes on dialysis therapy who presented with headache, unsteady gait, and slurred speech. We also consider presymptomatic metabolic abnormalities in the pathogenesis of this disease. PMID:24183109

Finelli, Pasquale F; Singh, Joseph U

2014-02-01

44

A selective role for right insula--basal ganglia circuits in appetitive stimulus processing  

PubMed Central

Hemispheric lateralization of hedonic evaluation (liking) and incentive motivation (wanting) in neural networks connecting the basal ganglia and insula (BG-I) in humans was examined. Participants with brain damage restricted to the BG-I of the right (n = 5) or left (n = 5) hemisphere, and 26 healthy participants matched on age, sex and intelligence quotient were tested on positively and negatively valenced pictures drawn from varied stimulus categories (Vijayaraghavan et al., 2008). Liking was assessed with explicit ratings of pleasantness using a nine-point Likert scale. Wanting was quantified as the amount of work (via repeated keypresses) that participants expended to increase (approach) or decrease (withdraw) viewing time. Right-lesion patients showed abnormally low viewing times and liking ratings for positive images. For a subset of positive images depicting sexual content, right-lesion patients exhibited active withdrawal, while the other two groups approached such stimuli. These results suggest that the right basal gangliainsula complex plays a greater role than the left in supporting hedonic evaluation and motivational approach to positively valenced stimuli. The finding that active avoidance of stimuli that were not liked was spared in both right- and left-sided lesion subjects suggests that unilateral damage to insula/basal ganglia circuits may not be sufficient to affect general incentive motivation independent of preference. PMID:22798397

Vijayaraghavan, Lavanya; Adolphs, Ralph; Kennedy, Daniel P.; Cassell, Martin; Tranel, Daniel; Paradiso, Sergio

2013-01-01

45

Bidirectional Control of Absence Seizures by the Basal Ganglia: A Computational Evidence  

PubMed Central

Absence epilepsy is believed to be associated with the abnormal interactions between the cerebral cortex and thalamus. Besides the direct coupling, anatomical evidence indicates that the cerebral cortex and thalamus also communicate indirectly through an important intermediate bridgebasal ganglia. It has been thus postulated that the basal ganglia might play key roles in the modulation of absence seizures, but the relevant biophysical mechanisms are still not completely established. Using a biophysically based model, we demonstrate here that the typical absence seizure activities can be controlled and modulated by the direct GABAergic projections from the substantia nigra pars reticulata (SNr) to either the thalamic reticular nucleus (TRN) or the specific relay nuclei (SRN) of thalamus, through different biophysical mechanisms. Under certain conditions, these two types of seizure control are observed to coexist in the same network. More importantly, due to the competition between the inhibitory SNr-TRN and SNr-SRN pathways, we find that both decreasing and increasing the activation of SNr neurons from the normal level may considerably suppress the generation of spike-and-slow wave discharges in the coexistence region. Overall, these results highlight the bidirectional functional roles of basal ganglia in controlling and modulating absence seizures, and might provide novel insights into the therapeutic treatments of this brain disorder. PMID:24626189

Wang, Tiebin; Jing, Wei; Xia, Yang; Xu, Peng; Luo, Cheng; Valdes-Sosa, Pedro A.; Yao, Dezhong

2014-01-01

46

A selective role for right insula--basal ganglia circuits in appetitive stimulus processing.  

PubMed

Hemispheric lateralization of hedonic evaluation ('liking') and incentive motivation ('wanting') in neural networks connecting the basal ganglia and insula (BG-I) in humans was examined. Participants with brain damage restricted to the BG-I of the right (n = 5) or left (n = 5) hemisphere, and 26 healthy participants matched on age, sex and intelligence quotient were tested on positively and negatively valenced pictures drawn from varied stimulus categories (Vijayaraghavan et al., 2008). Liking was assessed with explicit ratings of pleasantness using a nine-point Likert scale. Wanting was quantified as the amount of work (via repeated keypresses) that participants expended to increase (approach) or decrease (withdraw) viewing time. Right-lesion patients showed abnormally low viewing times and liking ratings for positive images. For a subset of positive images depicting sexual content, right-lesion patients exhibited active withdrawal, while the other two groups approached such stimuli. These results suggest that the right basal ganglia-insula complex plays a greater role than the left in supporting hedonic evaluation and motivational approach to positively valenced stimuli. The finding that active avoidance of stimuli that were not 'liked' was spared in both right- and left-sided lesion subjects suggests that unilateral damage to insula/basal ganglia circuits may not be sufficient to affect general incentive motivation independent of preference. PMID:22798397

Vijayaraghavan, Lavanya; Adolphs, Ralph; Kennedy, Daniel P; Cassell, Martin; Tranel, Daniel; Paradiso, Sergio

2013-10-01

47

Familial idiopathic basal ganglia calcification (Fahr`s disease).  

PubMed

Familial idiopathic basal ganglia calcification (Fahr`s disease) is a rare neurodegenerative disorder characterized by symmetrical and bilateral calcification of the basal ganglia. Calcifications may also occur in other brain regions such as dentate nucleus, thalamus, and cerebral cortex. Both familial and non-familial cases of Fahr`s disease have been reported, predominantly with autosomal-dominant fashion. The disease has a wide range of clinical presentations, predominantly with neuropsychiatric features and movement disorders. Psychiatric features reported in the literature include: cognitive impairment, depression, hallucinations, delusions, manic symptoms, anxiety, schizophrenia-like psychosis, and personality change. Other clinical features include: Parkinsonism, ataxia, headache, seizures, vertigo, stroke-like events, orthostatic hypotension, tremor, dysarthria, and paresis. Fahr`s disease should be considered in the differential diagnosis of psychiatric symptoms, particularly when associated with movement disorder. The disease should be differentiated from other conditions that can cause intracranial calcification. No specific treatment is currently available. Further research is needed to bridge the gap existing in our current knowledge of the prevalence, etiology, symptoms, and treatment of Fahr`s disease. PMID:24983277

Mufaddel, Amir A; Al-Hassani, Ghanem A

2014-07-01

48

The basal ganglia and cerebellum interact in the expression of dystonic movement  

PubMed Central

Dystonia is a neurological disorder characterized by excessive involuntary muscle contractions that lead to twisting movements or abnormal posturing. Traditional views place responsibility for dystonia with dysfunction of basal ganglia circuits, yet recent evidence has pointed towards cerebellar circuits as well. In the current studies we used two strategies to explore the hypothesis that the expression of dystonic movements depends on influences from a motor network that includes both the basal ganglia and cerebellum. The first strategy was to evaluate the consequences of subthreshold lesions of the striatum in two different animal models where dystonic movements are thought to originate from abnormal cerebellar function. The second strategy employed microdialysis to search for changes in striatal dopamine release in these two animal models where the cerebellum has been already implicated. One of the animal models involved tottering mice, which exhibit paroxysmal dystonia due to an inherited defect affecting calcium channels. In keeping with prior results implicating the cerebellum in this model, surgical removal of the cerebellum eliminated their dystonic attacks. In contrast, subclinical lesions of the striatum with either 6-hydroxydopamine (6OHDA) or quinolinic acid (QA) exaggerated their dystonic attacks. Microdialysis of the striatum revealed dystonic attacks in tottering mice to be associated with a significant reduction in extracellular striatal dopamine. The other animal model involved the induction of dystonia via pharmacological excitation of the cerebellar cortex by local application of kainic acid in normal mice. In this model the site of stimulation determines the origin of dystonia in the cerebellum. However, subclinical striatal lesions with either 6OHDA or QA again exaggerated their generalized dystonia. When dystonic movements were triggered by pharmacological stimulation of the cerebellum, microdialysis revealed significant reductions in striatal dopamine release. These results demonstrate important functional relationships between cerebellar and basal ganglia circuits in two different animal models of dystonia. They suggest that expression of dystonic movements depends on influences from both basal ganglia and cerebellum in both models. These results support the hypothesis that dystonia may result from disruption of a motor network involving both the basal ganglia and cerebellum, rather than isolated dysfunction of only one motor system. PMID:18669484

Neychev, Vladimir K.; Fan, Xueliang; Mitev, V. I.; Hess, Ellen J.

2008-01-01

49

The basal ganglia and cerebellum interact in the expression of dystonic movement.  

PubMed

Dystonia is a neurological disorder characterized by excessive involuntary muscle contractions that lead to twisting movements or abnormal posturing. Traditional views place responsibility for dystonia with dysfunction of basal ganglia circuits, yet recent evidence has pointed towards cerebellar circuits as well. In the current studies we used two strategies to explore the hypothesis that the expression of dystonic movements depends on influences from a motor network that includes both the basal ganglia and cerebellum. The first strategy was to evaluate the consequences of subthreshold lesions of the striatum in two different animal models where dystonic movements are thought to originate from abnormal cerebellar function. The second strategy employed microdialysis to search for changes in striatal dopamine release in these two animal models where the cerebellum has been already implicated. One of the animal models involved tottering mice, which exhibit paroxysmal dystonia due to an inherited defect affecting calcium channels. In keeping with prior results implicating the cerebellum in this model, surgical removal of the cerebellum eliminated their dystonic attacks. In contrast, subclinical lesions of the striatum with either 6-hydroxydopamine (6OHDA) or quinolinic acid (QA) exaggerated their dystonic attacks. Microdialysis of the striatum revealed dystonic attacks in tottering mice to be associated with a significant reduction in extracellular striatal dopamine. The other animal model involved the induction of dystonia via pharmacological excitation of the cerebellar cortex by local application of kainic acid in normal mice. In this model the site of stimulation determines the origin of dystonia in the cerebellum. However, subclinical striatal lesions with either 6OHDA or QA again exaggerated their generalized dystonia. When dystonic movements were triggered by pharmacological stimulation of the cerebellum, microdialysis revealed significant reductions in striatal dopamine release. These results demonstrate important functional relationships between cerebellar and basal ganglia circuits in two different animal models of dystonia. They suggest that expression of dystonic movements depends on influences from both basal ganglia and cerebellum in both models. These results support the hypothesis that dystonia may result from disruption of a motor network involving both the basal ganglia and cerebellum, rather than isolated dysfunction of only one motor system. PMID:18669484

Neychev, Vladimir K; Fan, Xueliang; Mitev, V I; Hess, Ellen J; Jinnah, H A

2008-09-01

50

Familial idiopathic basal ganglia calcification (Fahr's disease) without neurological, cognitive and psychiatric symptoms is not linked to the IBGC1 locus on chromosome 14q  

Microsoft Academic Search

Idiopathic basal ganglia calcification (IBGC) is characterised by radiological, neurological, cognitive and psychiatric abnormalities. The associations between these abnormal phenotypes and abnormal genes remain unclear despite the recent mapping to chromosome 14q of a susceptibility locus for IBGC (IBGC1). We identified two siblings, from a large multigenerational pedigree, who had both been diagnosed with radiological IBGC, dementia, bipolar affective disorder

Henry Brodaty; Philip Mitchell; Georgina Luscombe; John B. J. Kwok; Renee F. Badenhop; Rod McKenzie; Peter R. Schofield

2002-01-01

51

Basal ganglia-cortical interactions in Parkinsonian patients  

PubMed Central

Parkinson's disease is a common and debilitating condition, caused by aberrant activity in a complex basal gangliathalamocortical circuit. Therapeutic advances rely on characterising interactions in this circuit. However, recording electrophysiological responses over the entire circuit is impractical. Dynamic causal modelling offers large-scale models of predictive value based on a limited or partial sampling of complex networks. Using dynamic causal modelling, we determined the network changes underlying the pathological excess of beta oscillations that characterise the Parkinsonian state. We modelled data from five patients undergoing surgery for deep brain stimulation of more than one target. We found that connections to and from the subthalamic nucleus were strengthened and promoted beta synchrony, in the untreated compared to the treated Parkinsonian state. Dynamic causal modelling was able to replicate the effects of lesioning this nucleus and may provide a new means of directing the search for therapeutic targets. PMID:23153964

Marreiros, Andre C.; Cagnan, Hayriye; Moran, Rosalyn J.; Friston, Karl J.; Brown, Peter

2013-01-01

52

Influences of the basal ganglia on the medullary reticular formation.  

PubMed

Units were recorded extracellularly in the medullary reticular formation of chloralose-anesthetized cats during electrical stimulation of the basal ganglia (BG). Stimulating portions of the BG (caudate nucleus, entopeduncular nucleus, substantia nigra) evoked unit responses in a considerable proportion of these neurons. The majority of reticular cells that were affected by the BG were also receptive to somatic sensory inputs from the face. These units' sensory properties were influenced by BG stimulation. Cells exclusively responsive to either BG or facial inputs were uncommon. The areas of the reticular formation affected by the BG give rise to portions of the reticulospinal tracts and thereby afford the BG access to the final common path. PMID:3587734

Manetto, C; Lidsky, T I

1987-04-10

53

Disconnection syndromes of basal ganglia, thalamus, and cerebrocerebellar systems  

PubMed Central

Disconnection syndromes were originally conceptualized as a disruption of communication between different cerebral cortical areas. Two developments mandate a re-evaluation of this notion. First, we present a synopsis of our anatomical studies in monkey elucidating principles of organization of cerebral cortex. Efferent fibers emanate from every cortical area, and are directed with topographic precision via association fibers to ipsilateral cortical areas, commissural fibers to contralateral cerebral regions, striatal fibers to basal ganglia, and projection subcortical bundles to thalamus, brainstem and/or pontocerebellar system. We note that cortical areas can be defined by their patterns of subcortical and cortical connections. Second, we consider motor, cognitive and neuropsychiatric disorders in patients with lesions restricted to basal ganglia, thalamus, or cerebellum, and recognize that these lesions mimic deficits resulting from cortical lesions, with qualitative differences between the manifestations of lesions in functionally related areas of cortical and subcortical nodes. We consider these findings on the basis of anatomical observations from tract tracing studies in monkey, viewing them as disconnection syndromes reflecting loss of the contribution of subcortical nodes to the distributed neural circuits. We introduce a new theoretical framework for the distributed neural circuits, based on general, and specific, principles of anatomical organization, and on the architecture of the nodes that comprise these systems. We propose that neural architecture determines function, i.e., each architectonically distinct cortical and subcortical area contributes a unique transform, or computation, to information processing; anatomically precise and segregated connections between nodes define behavior; and association fiber tracts that link cerebral cortical areas with each other enable the cross-modal integration required for evolved complex behaviors. This model enables the formulation and testing of future hypotheses in investigations using evolving magnetic resonance imaging techniques in humans, and in clinical studies in patients with cortical and subcortical lesions. PMID:18614161

Schmahmann, Jeremy D.; Pandya, Deepak N.

2013-01-01

54

Symbolic Reasoning in Spiking Neurons: A Model of the Cortex/Basal Ganglia/Thalamus Loop  

E-print Network

Symbolic Reasoning in Spiking Neurons: A Model of the Cortex/Basal Ganglia/Thalamus Loop Terrence C of the cortex, basal ganglia, and thalamus. The model is a general- purpose neural controller which plays a role for selecting between a set of inferences. When an inference rule is selected, it commands the thalamus

Anderson, Charles H.

55

The Evolution of the Terminology of the Basal Ganglia, or are they Nuclei?  

Microsoft Academic Search

Basal ganglia have been generally used to refer to some subcortical nuclei. However, it is a misnomer since ganglion is a group of nerve cells especially located outside of the brain or spinal cord. We evaluated the terminology of the basal ganglia from historical and terminological points of view.

Levent Sarikcioglu; Ummuhan Altun; Bikem Suzen; Nurettin Oguz

2008-01-01

56

Distinct Hippocampal and Basal Ganglia Contributions to Probabilistic Learning and Reversal  

ERIC Educational Resources Information Center

The hippocampus and the basal ganglia are thought to play fundamental and distinct roles in learning and memory, supporting two dissociable memory systems. Interestingly, however, the hippocampus and the basal ganglia have each, separately, been implicated as necessary for reversal learning--the ability to adaptively change a response when

Shohamy, Daphna; Myers, Catherine E.; Hopkins, Ramona O.; Sage, Jake; Gluck, Mark A.

2009-01-01

57

Task-Set Switching Deficits in Early-Stage Huntington's Disease: Implications for Basal Ganglia Function  

Microsoft Academic Search

Executive functions are likely mediated by interconnected circuits including frontal lobe and basal ganglia structures. We assessed the executive function of task switching in patients with early-stage Huntington' s disease (HD), a neurodegenerative disease affecting the basal ganglia. In two experiments, the HD patients had greater difficulty when switching than when repeating a task than matched controls, and this was

Adam R. Aron; Laura Watkins; Barbara J. Sahakian; Stephen Monsell; Roger A. Barker; Trevor W. Robbins

2003-01-01

58

Targeting optimal biopsy location in basal ganglia germinoma using 11C-methionine positron emission tomography  

Microsoft Academic Search

BackgroundApproximately 5% to 10% of intracranial germinomas arise from the basal ganglia or thalamus. Diagnosis is usually made by stereotactic biopsy, and precise location of the biopsy target is crucial because germinoma in these sites is potentially curable. We herein describe a case with germinoma in the basal ganglia that showed nonspecific clinical and radiological findings. The usefulness of MET-PET

Nobuyuki Kawai; Keisuke Miyake; Yoshihiro Nishiyama; Yuka Yamamoto; Akihiro Miki; Reiji Haba; Tadashi Imai; Takashi Tamiya; Seigo Nagao

2008-01-01

59

Vocal babbling in songbirds requires the basal ganglia-recipient motor thalamus but not the basal ganglia  

PubMed Central

Young songbirds produce vocal babbling, and the variability of their songs is thought to underlie a process of trial-and-error vocal learning. It is known that this exploratory variability requires the cortical component of a basal ganglia (BG) thalamocortical loop, but less understood is the role of the BG and thalamic components in this behavior. We found that large bilateral lesions to the songbird BG homolog Area X had little or no effect on song variability during vocal babbling. In contrast, lesions to the BG-recipient thalamic nucleus DLM (medial portion of the dorsolateral thalamus) largely abolished normal vocal babbling in young birds and caused a dramatic increase in song stereotypy. These findings support the idea that the motor thalamus plays a key role in the expression of exploratory juvenile behaviors during learning. PMID:21430276

Goldberg, Jesse H.

2011-01-01

60

Vocal babbling in songbirds requires the basal ganglia-recipient motor thalamus but not the basal ganglia.  

PubMed

Young songbirds produce vocal "babbling," and the variability of their songs is thought to underlie a process of trial-and-error vocal learning. It is known that this exploratory variability requires the "cortical" component of a basal ganglia (BG) thalamocortical loop, but less understood is the role of the BG and thalamic components in this behavior. We found that large bilateral lesions to the songbird BG homolog Area X had little or no effect on song variability during vocal babbling. In contrast, lesions to the BG-recipient thalamic nucleus DLM (medial portion of the dorsolateral thalamus) largely abolished normal vocal babbling in young birds and caused a dramatic increase in song stereotypy. These findings support the idea that the motor thalamus plays a key role in the expression of exploratory juvenile behaviors during learning. PMID:21430276

Goldberg, Jesse H; Fee, Michale S

2011-06-01

61

Input to the lateral habenula from the basal ganglia is excitatory, aversive, and suppressed by serotonin  

PubMed Central

Summary The lateral habenula (LHb) has recently been identified as a key regulator of the reward system by driving inhibition onto dopaminergic neurons. However, the nature and potential modulation of the major input to the LHb originating from the basal ganglia are poorly understood. Although the output of the basal ganglia is thought to be primarily inhibitory, here we show that transmission from the basal ganglia to the LHb is excitatory, glutamatergic and suppressed by serotonin. Behaviorally, activation of this pathway is aversive, consistent with its role as an anti-reward signal. Our demonstration of an excitatory projection from the basal ganglia to the LHb explains how LHb-projecting basal ganglia neurons can have similar encoding properties as LHb neurons themselves. Our results also provide a link between anti-reward excitatory synapses and serotonin, a neuromodulator implicated in depression. PMID:22578499

Shabel, Steven J.; Proulx, Christophe D.; Trias, Anthony; Murphy, Ryan T.; Malinow, Roberto

2012-01-01

62

Dopaminergic Control of the Exploration-Exploitation Trade-Off via the Basal Ganglia  

PubMed Central

We continuously face the dilemma of choosing between actions that gather new information or actions that exploit existing knowledge. This exploration-exploitation trade-off depends on the environment: stability favors exploiting knowledge to maximize gains; volatility favors exploring new options and discovering new outcomes. Here we set out to reconcile recent evidence for dopamines involvement in the exploration-exploitation trade-off with the existing evidence for basal ganglia control of action selection, by testing the hypothesis that tonic dopamine in the striatum, the basal ganglias input nucleus, sets the current exploration-exploitation trade-off. We first advance the idea of interpreting the basal ganglia output as a probability distribution function for action selection. Using computational models of the full basal ganglia circuit, we showed that, under this interpretation, the actions of dopamine within the striatum change the basal ganglias output to favor the level of exploration or exploitation encoded in the probability distribution. We also found that our models predict striatal dopamine controls the exploration-exploitation trade-off if we instead read-out the probability distribution from the target nuclei of the basal ganglia, where their inhibitory input shapes the cortical input to these nuclei. Finally, by integrating the basal ganglia within a reinforcement learning model, we showed how dopamines effect on the exploration-exploitation trade-off could be measurable in a forced two-choice task. These simulations also showed how tonic dopamine can appear to affect learning while only directly altering the trade-off. Thus, our models support the hypothesis that changes in tonic dopamine within the striatum can alter the exploration-exploitation trade-off by modulating the output of the basal ganglia. PMID:22347155

Humphries, Mark D.; Khamassi, Mehdi; Gurney, Kevin

2012-01-01

63

What do the basal ganglia do? A modeling perspective.  

PubMed

Basal ganglia (BG) constitute a network of seven deep brain nuclei involved in a variety of crucial brain functions including: action selection, action gating, reward based learning, motor preparation, timing, etc. In spite of the immense amount of data available today, researchers continue to wonder how a single deep brain circuit performs such a bewildering range of functions. Computational models of BG have focused on individual functions and fail to give an integrative picture of BG function. A major breakthrough in our understanding of BG function is perhaps the insight that activities of mesencephalic dopaminergic cells represent some form of 'reward' to the organism. This insight enabled application of tools from 'reinforcement learning,' a branch of machine learning, in the study of BG function. Nevertheless, in spite of these bright spots, we are far from the goal of arriving at a comprehensive understanding of these 'mysterious nuclei.' A comprehensive knowledge of BG function has the potential to radically alter treatment and management of a variety of BG-related neurological disorders (Parkinson's disease, Huntington's chorea, etc.) and neuropsychiatric disorders (schizophrenia, obsessive compulsive disorder, etc.) also. In this article, we review the existing modeling literature on BG and hypothesize an integrative picture of the function of these nuclei. PMID:20644953

Chakravarthy, V S; Joseph, Denny; Bapi, Raju S

2010-09-01

64

Microcircuitry of the direct and indirect pathways of the basal ganglia.  

PubMed

Our understanding of the organization of the basal ganglia has advanced markedly over the last 10 years, mainly due to increased knowledge of their anatomical, neurochemical and physiological organization. These developments have led to a unifying model of the functional organization of the basal ganglia in both health and disease. The hypothesis is based on the so-called "direct" and "indirect" pathways of the flow of cortical information through the basal ganglia and has profoundly influenced the field of basal ganglia research, providing a framework for anatomical, physiological and clinical studies. The recent introduction of powerful techniques for the analysis of neuronal networks has led to further developments in our understanding of the basal ganglia. The objective of this commentary is to build upon the established model of the basal ganglia connectivity and review new anatomical findings that lead to the refinement of some aspects of the model. Four issues will be discussed. (1) The existence of several routes for the flow of cortical information along "indirect" pathways. (2) The synaptic convergence of information flowing through the "direct" and "indirect" pathways at the single-cell level in the basal ganglia output structures. (3) The convergence of functionally diverse information from the globus pallidus and the ventral pallidum at different levels of the basal ganglia. (4) The interconnections between the two divisions of the pallidal complex and the subthalamic nucleus and the characterization of the neuronal network underlying the indirect pathways. The findings summarized in this commentary confirm and elaborate the models of the direct and indirect pathways of information flow through the basal ganglia and provide a morphological framework for future studies. PMID:9881853

Smith, Y; Bevan, M D; Shink, E; Bolam, J P

1998-09-01

65

Cognitive deficits in animal models of basal ganglia disorders.  

PubMed

The two most common neurological disorders of the basal ganglia are Parkinson's disease (PD) and Huntington's disease (HD). The most overt symptoms of these diseases are motoric, reflecting the loss of the striatal medium spiny neurons in HD and ascending substantia nigra dopaminergic cells in PD. However, both disease processes induce insidious psychiatric and cognitive syndromes that can manifest well in advance of the onset of motor deficits. These early deficits provide an opportunity for prophylactic therapeutic intervention in order to retard disease progression from the earliest possible point. In order to exploit this opportunity, animal models of HD and PD are being probed for the specific cognitive deficits represented in the disease states. At the neuronal level, these deficits are typically, but not exclusively, mediated by disruption of parallel corticostriatal loops that integrate motor information with sensory and higher order, "executive" cognitive functions. Dysfunction in these systems can be probed with sensitive behavioural tests that selectively probe these cognitive functions in mouse models with focal lesions of striatal or cortical regions, or of specific neurotransmitter systems. Typically these tests were designed and validated in rats. With the advent of genetically modified mouse models of disease, validated tests provide an opportunity to screen mouse models of disease for early onset cognitive deficits. This review seeks to draw together the literature on cognitive deficits in HD and PD, to determine the extent to which these deficits are represented in the current animal models of disease, and to evaluate the viability of selecting cognitive deficits as potential therapeutic targets. This article is part of a Special Issue entitled 'Animal Models'. PMID:22588013

Brooks, Simon P; Dunnett, Stephen B

2013-03-01

66

Quantitation of the human basal ganglia with Positron Emission Tomography  

SciTech Connect

The accurate measurement of the concentration of a radioisotope in small structures with PET requires a correction for quantitation loss due to the partial volume effect and the effect of scattered radiation. To evaluate errors associated with measures in the human basal ganglia (BG) we have built a unilateral model of the BG that we have inserted in a 20 cm cylinder. The recovery coefficient (RC = measured activity/true activity) for our BG phantom has been measured on a CTI tomograph (model 931-08/12) with different background concentrations (contrast) and at different axial locations in the gantry. The BG was visualized on 4 or 5 slices depending on its position in the gantry and on the contrast used. The RC was 0.75 with no background (contrast equal to 1.0). Increasing the relative radioactivity concentration in the background increased the RC from 0.75 to 2.00 when the contrast was {minus}0.7 (BG < Background). The RC was also affected by the size and the shape of the region of interest (ROI) used (RC from 0.75 to 0.67 with ROI size from 0.12 to 1.41 cm{sup 2}). These results show that accurate RC correction depends not only on the volume of the structure but also on its contrast with its surroundings as well as on the selection of the ROI. They also demonstrate that the higher the contrast the more sensitive to axial positioning PET measurements in the BG are. These data provide us with some information about the variability of PET measurements in small structure like the BG and we have proposed some strategies to improve the reproducibility. 18 refs., 3 figs., 5 tabs.

Bendriem, B.; Dewey, S.L.; Schlyer, D.J.; Wolf, A.P.; Volkow, N.D.

1990-01-01

67

Modeling the role of the basal ganglia in motor control and motor programming  

E-print Network

The basal ganglia (BG) are a group of highly interconnected nuclei buried deep in the brain. They are involved in an important range of brain functions, including both lower-level movement control and higher-level cognitive ...

Mao, Zhi-Hong, 1972-

2005-01-01

68

Anatomy of a songbird basal ganglia circuit essential for vocal learning and plasticity  

PubMed Central

Vocal learning in songbirds requires an anatomically discrete and functionally dedicated circuit called the anterior forebrain pathway (AFP). The AFP is homologous to cortico-basal ganglia-thalamo-cortical loops in mammals. The basal ganglia portion of this pathway, Area X, shares many features characteristic of the mammalian striatum and pallidum, including cell-types and connectivity. The AFP also deviates from mammalian basal ganglia circuits in fundamental ways. In addition, the microcircuitry, role of neuromodulators, and function of Area X are still unclear. Elucidating the mechanisms by which both mammalian-like and unique features of the AFP contribute to vocal learning may help lead to a broad understanding of the sensorimotor functions of basal ganglia circuits. PMID:19596062

Gale, Samuel D.; Perkel, David J.

2009-01-01

69

The involvement of the primate frontal cortex-basal ganglia system in arbitrary visuomotor association learning  

E-print Network

It is the goal of this thesis to examine the frontal cortex-basal ganglia system during arbitrary visuomotor association learning, the forming of arbitrary links between visual stimuli and motor responses (e.g. red means ...

Machon, Michelle S

2009-01-01

70

Structural analysis of the basal ganglia in schizophrenia Daniel Mamah a,, Lei Wang a  

E-print Network

mapping; Shape analysis 1. Introduction The basal ganglia are a collection of nuclei deep within, emotional and cognitive dysfunction has been Schizophrenia Research xx (2006) xxx­xxx + MODEL SCHRES-02933

71

Changes in basal ganglia processing of cortical input following magnetic stimulation in Parkinsonism  

E-print Network

Available online 31 July 2012 Keywords: Transcranial magnetic stimulation (TMS) Parkinson's disease Primate of transcranial magnetic stimulation (TMS) in human patients of different disorders may result in differentChanges in basal ganglia processing of cortical input following magnetic stimulation

Bar-Gad, Izhar

72

A basal ganglia-forebrain circuit in the songbird biases motor output to avoid vocal errors  

E-print Network

In songbirds, as in mammals, basal ganglia-forebrain circuits are necessary for the learning and production of complex motor behaviors; however, the precise role of these circuits remains unknown. It has recently been shown ...

Andalman, Aaron S.

73

Extensive basal ganglia edema caused by a traumatic carotid-cavernous fistula: a rare presentation related to a basal vein of Rosenthal anatomical variation.  

PubMed

The authors report a very rare presentation of traumatic carotid-cavernous fistula (CCF) with extensive edema of the basal ganglia and brainstem because of an anatomical variation of the basal vein of Rosenthal (BVR). A 45-year-old woman was admitted to the authors' institution for left hemiparesis, dysarthria, and a comatose state caused by right orbital trauma from a thin metal rod. Brain MRI showed a right CCF and vasogenic edema of the right side of the brainstem, right temporal lobe, and basal ganglia. Digital subtraction angiography confirmed a high-flow direct CCF and revealed a hypoplastic second segment of the BVR responsible for the hypertension in inferior striate veins and venous congestion. Endovascular treatment was performed on an emergency basis. One month after treatment, the patient's symptoms and MRI signal abnormalities almost totally disappeared. Basal ganglia and brainstem venous congestion may occur in traumatic CCF in cases of a hypoplastic or agenetic second segment of the BVR and may provoke emergency treatment. PMID:24527815

Ract, Isabelle; Drier, Aurlie; Leclercq, Delphine; Sourour, Nader; Gabrieli, Joseph; Yger, Marion; Nouet, Aurlien; Dormont, Didier; Chiras, Jacques; Clarenon, Frdric

2014-07-01

74

Dopaminergic dysbalance in distinct basal ganglia neurocircuits: implications for the pathophysiology of Parkinson's disease, schizophrenia and attention deficit hyperactivity disorder.  

PubMed

The basal ganglia form a forebrain system that collects signals from a large part of the neocortex, redistributes these cortical inputs both with respect to one another and with respect to inputs from the limbic system, and then focuses the inputs of this redistributed, integrated signals into particular regions of the frontal lobes and brainstem involved in aspects of motor planning and motor memory. Movement disorders associated with basal ganglia dysfunction comprise a spectrum of abnormalities that range from the hypokinetic disorder (from which Parkinson's disease, PD, is the best-known-example) at one extreme to the hyperkinetic disorder (exemplified by Huntington's disease and hemiballism) at the other. In addition to disorders of movement, major mental disorders including schizophrenic-like states and attention deficit hyperactivity disorder (ADHD) have been linked to abnormalities in the basal ganglia and their allied nuclei. In this paper we discuss recent evidence indicating that a dopamine-induced dysbalance of basal ganglia neurocircuitries may be an important pathophysiological component in PD, schizophrenia and ADHD. According to our model, the deprivation of dopaminergic nigro-striatal input, as in PD, reduces the positive feedback via the direct system, and increases the negative feedback via the indirect system. The critical consequences are an overactivity of the basal ganglia output sites with the resulting inhibition of thalamo-cortical drive. In schizophrenia the serious cognitive deficits might be partly a result of a hyperactivity of the inhibitory dopamine D(2) transmission system. Through this dysinhibition, the thalamus exhibits hyperactivity that overstimulates the cortex resulting in dysfunctions of perception, attention, stimulus distinction, information processing and affective regulation (inducing hallucinations and delusions) and motor disabilities. Recent studies have strongly suggested that a disturbance of the dopaminergic system is also involved in the pathophysiology of ADHD. The most convincing evidence comes from the demonstration of the efficacy of psychostimulants such as the dopamine transporter (DAT) blocker methylphenidate in the symptomatic treatment of ADHD. Genetic studies have shown an association between ADHD and genes involved in dopaminergic neurotransmission (for example the dopamine receptor genes DRD4 and DRD5, and the DAT gene DAT1). DAT knockout mice display a phenotype with increased locomotor activity, which is normalized by psychostimulant treatment. Finally, imaging studies demonstrated an increased density of DAT in the striatum of ADHD patients. Which system is disturbed and whether this system is hyper- or hypoactive is not unambiguously known yet. PMID:17197367

Mehler-Wex, C; Riederer, P; Gerlach, M

2006-12-01

75

A review of pathologies associated with high T1W signal intensity in the basal ganglia on Magnetic Resonance Imaging  

PubMed Central

Summary With several functions and a fundamental influence over cognition and motor functions, the basal ganglia are the cohesive centre of the brain. There are several conditions which affect the basal ganglia and these have various clinical and radiological manifestations. Nevertheless, on magnetic resonance imaging there is a limited differential diagnosis for those conditions presenting with T1 weighted spin echo hyperintensity within the central nervous system in general and the basal ganglia in particular. The aim of our review is to explore some of these basal ganglia pathologies and provide image illustrations. PMID:24900164

Zaitout, Zahia; Romanowski, Charles; Karunasaagarar, Kavitasagary; Connolly, Daniel; Batty, Ruth

2014-01-01

76

Hypofractionated Stereotactic Radiosurgery in a Large Bilateral Thalamic and Basal Ganglia Arteriovenous Malformation  

PubMed Central

Purpose. Arteriovenous malformations (AVMs) in the basal ganglia and thalamus have a more aggressive natural history with a higher morbidity and mortality than AVMs in other locations. Optimal treatmentcomplete obliteration without new neurological deficitsis often challenging. We present a patient with a large bilateral basal ganglia and thalamic AVM successfully treated with hypofractionated stereotactic radiosurgery (HFSRS) with intensity modulated radiotherapy (IMRT). Methods. The patient was treated with hypofractionated stereotactic radiosurgery to 30?Gy at margin in 5 fractions of 9 static fields with a minimultileaf collimator and intensity modulated radiotherapy. Results. At 10 months following treatment, digital subtraction angiography showed complete obliteration of the AVM. Conclusions. Large bilateral thalamic and basal ganglia AVMs can be successfully treated with complete obliteration by HFSRS with IMRT with relatively limited toxicity. Appropriate caution is recommended. PMID:24307961

Nanda, Ashish; Litofsky, N. Scott

2013-01-01

77

Goal-directed and habitual control in the basal ganglia: implications for Parkinson's disease  

PubMed Central

Progressive loss of the ascending dopaminergic projection in the basal ganglia is a fundamental pathological feature of Parkinsons disease. Studies in animals and humans have identified spatially segregated functional territories in the basal ganglia for the control of goal-directed and habitual actions. In patients with Parkinsons disease the loss of dopamine is predominantly in the posterior putamen, a region of the basal ganglia associated with the control of habitual behaviour. These patients may therefore be forced into a progressive reliance on the goal-directed mode of action control that is mediated by comparatively preserved processing in the rostromedial striatum. Thus, many of their behavioural difficulties may reflect a loss of normal automatic control owing to distorting output signals from habitual control circuits, which impede the expression of goal-directed action. PMID:20944662

Redgrave, Peter; Rodriguez, Manuel; Smith, Yoland; Rodriguez-Oroz, Maria C.; Lehericy, Stephane; Bergman, Hagai; Agid, Yves; DeLong, Mahlon R.; Obeso, Jose A.

2011-01-01

78

ROLE OF A LATERALIZED PARIETAL-BASAL GANGLIA CIRCUIT IN HIERARCHICAL PATTERN PERCEPTION  

PubMed Central

The role of corticostriatal circuits in hierarchical pattern perception was examined in Parkinsons disease. The hypothesis was tested that patients with right-side onset of motor symptoms (RPD, left hemisphere dysfunction) would be impaired at local level processing because the left posterior temporoparietal junction (TP) emphasizes processing of local information. By contrast, left-side onset patients (LPD; right hemisphere dysfunction) would show impaired global processing because right TP emphasizes global processing. Participants identified targets at local or global levels without and with attention biased toward those levels. Despite normal attentional control between levels, LPD patients showed a single dissociation, demonstrating abnormal global level processing under all conditions, whereas RPD patients showed abnormal local level processing mainly when attention was biased toward the local level. These findings link side of motor symptom onset to visuospatial cognitive abilities that depend upon the contralateral TP, highlighting that side of onset can predict visuospatial impairments, and provide evidence that an inferior parietal - basal ganglia pathway involving the caudate head and the hemispherically asymmetrical TP region is necessary for hierarchical pattern perception. PMID:19170437

Schendan, Haline E.; Amick, Melissa M.; Cronin-Golomb, Alice

2009-01-01

79

Hyporesponsive reward anticipation in the basal ganglia following severe institutional deprivation early in life.  

PubMed

Severe deprivation in the first few years of life is associated with multiple difficulties in cognition and behavior. However, the brain basis for these difficulties is poorly understood. Structural and functional neuroimaging studies have implicated limbic system structures as dysfunctional, and one functional imaging study in a heterogeneous group of maltreated individuals has confirmed the presence of abnormalities in the basal ganglia. Based on these studies and known dopaminergic abnormalities from studies in experimental animals using social isolation, we used a task of monetary reward anticipation to examine the functional integrity of brain regions previously shown to be implicated in reward processing. Our sample included a group of adolescents (n = 12) who had experienced global deprivation early in their lives in Romania prior to adoption into UK families. In contrast to a nonadopted comparison group (n = 11), the adoptees did not recruit the striatum during reward anticipation despite comparable performance accuracy and latency. These results show, for the first time, an association between early institutional deprivation and brain reward systems in humans and highlight potential neural vulnerabilities resulting from such exposures. PMID:19929329

Mehta, Mitul A; Gore-Langton, Emma; Golembo, Nicole; Colvert, Emma; Williams, Steven C R; Sonuga-Barke, Edmund

2010-10-01

80

Motor functions of cerebellum and basal ganglia: the cerebellocortical saccadic (ballistic) clock, the cerebellonuclear hold regulator, and the basal ganglia ramp (voluntary speed smooth movement) generator  

Microsoft Academic Search

A theory of the motor functions of the cerebellum and the basal ganglia is presented. It is based on the following observations:1.Dysmetria of saccadic eye and rapid arm movements as well as adiadochokinesis as a consequence of cerebellar cortical lesions.2.Holding tremor of the arm and eyes (pendular nystagmus) due to lesions of the cerebellar nuclei.3.The precentral motor cortex is unnecessary

H. H. Kornhuber

1971-01-01

81

1H MRS of basal ganglia and thalamus in amyotrophic lateral sclerosis  

PubMed Central

Previous studies have evaluated motor and extramotor cerebral cortical regions in patients with amyotrophic lateral sclerosis (ALS) using 1H MRS, but none have evaluated the thalamus or basal ganglia. The objective of this exploratory study was to evaluate the subclinical involvement of the basal ganglia and thalamus in patients with ALS using 1H MRS. Fourteen patients (52 7 years) with sporadic definite ALS and 17 age-matched controls were studied using volumetric MRSI on a 3-T scanner. The concentration of the metabolites N-acetylaspartate (NAA), choline (Cho) and their ratio (NAA/Cho) were obtained bilaterally from the basal ganglia (lentiform nucleus, caudate) and thalamus. The maximum rates of finger and foot tap and lip and tongue movements were obtained to assess extrapyramidal and pyramidal tract function. In patients with ALS, relative to controls, the NAA concentration was significantly lower (p < 0.02) in the basal ganglia and thalamus, and the Cho concentration was higher (p < 0.01) in these structures, except in the caudate (p = 0.04). Correspondingly, the NAA/Cho ratio was significantly lower (p < 0.01) in these structures, except in the caudate (p = 0.03), in patients than in controls. There were mild to strong correlations (r = 0.40.7) between the metabolites of the basal ganglia and finger tap, foot tap and lip and tongue movement rates. In conclusion, decreased NAA in the basal ganglia and thalamus and increased Cho and decreased NAA/Cho in the lentiform nucleus and thalamus are indicative of neuronal loss or dysfunction and alterations in choline-containing membranes in these structures. PMID:21404355

Sharma, Khema R.; Saigal, Gaurav; Maudsley, Andrew A.; Govind, Varan

2011-01-01

82

An entropy-based model for basal ganglia dysfunctions in movement disorders.  

PubMed

During this last decade, nonlinear analyses have been used to characterize the irregularity that exists in the neuronal data stream of the basal ganglia. In comparison to linear parameters for disparity (i.e., rate, standard deviation, and oscillatory activities), nonlinear analyses focus on complex patterns that are composed of groups of interspike intervals with matching lengths but not necessarily contiguous in the data stream. In light of recent animal and clinical studies, we present a review and commentary on the basal ganglia neuronal entropy in the context of movement disorders. PMID:23762856

Darbin, Olivier; Dees, Daniel; Martino, Anthony; Adams, Elizabeth; Naritoku, Dean

2013-01-01

83

Shedding new light on the role of the basal ganglia-superior colliculus pathway in eye movements  

PubMed Central

SUMMARY A large body of work spanning 25+ years provides compelling evidence for the involvement of the basal ganglia-superior colliculus pathway in the initiation of rapid, orienting movements of the eyes, called saccades. The role of this pathway in saccade control is similar to the role of the basal ganglia-thalamic pathway in the control of skeletal movement: a transient cessation in tonic inhibition supplied by the basal ganglia to motor structures releases movements via the direct pathway whereas a transient increase in inhibition by the basal ganglia to motor structures prevents movements via the indirect pathway. In parallel with recent advances in the study and treatment of patients with basal ganglia disease and in animal experiments in the skeletal motor system, the results of studies exploring the role of the basal ganglia-superior colliculus pathway in saccades highlight the need for a revisiting of our understanding of the role of this pathway in saccades. The discovery of many different response profiles of neurons in the substantia nigra pars reticulata of the basal ganglia and in the superior colliculus, coupled with advances in experimental and statistical techniques including sophisticated behavioral procedures and multiple neuron recording and analysis, point toward a role for the basal ganglia-superior colliculus pathway in cognitive events intervening between vision and action, such as memory, target selection and saccade choice and valuation. PMID:20829033

Shires, Joel; Joshi, Siddhartha; Basso, Michele A.

2010-01-01

84

Stuttering and the Basal Ganglia Circuits: A Critical Review of Possible Relations  

ERIC Educational Resources Information Center

The possible relation between stuttering and the basal ganglia is discussed. Important clues to the pathophysiology of stuttering are given by conditions known to alleviate dysfluency, like the rhythm effect, chorus speech, and singing. Information regarding pharmacologic trials, lesion studies, brain imaging, genetics, and developmental changes

Alm, Per A.

2004-01-01

85

Point process models show temporal dependencies of basal ganglia nuclei under Deep Brain Stimulation  

Microsoft Academic Search

Deep Brain Stimulation (DBS) is an effective treatment for patients with Parkinsons disease, but its impact on basal ganglia nuclei is not fully understood. DBS applied to the subthalamic nucleus (STN) affects neurons in the Globus Pallidus pars interna (GPi) through direct projections, as well as indirectly through the Globus Pallidus pars externa (GPe). Since traditional statistical analyses of electrophysiological

Shreya Saxena; Sabato Santaniello; Erwin B. Montgomery; John T. Gale; Sridevi V. Sarma

2010-01-01

86

TOPIC 9: The Basal Ganglia -group of subcortical nuclei (4 main parts)  

E-print Network

) Output from Basal Ganglia To motor areas via the thalamus --> from Globus Pallidus (int.) and To eye mvt, Sinauer Associates Inc: Massachusetts, 2001. Motor cortex Caudate Thalamus Subthalamic nucleus Substantia (tonic) Motor cortex Caudate Thalamus Subthalamic nucleus Substantia nigra pars reticulata GP -int GP

Sergio, Lauren E.

87

The Role of the Basal Ganglia in Implicit Contextual Learning: A Study of Parkinson's Disease  

ERIC Educational Resources Information Center

Implicit contextual learning refers to the ability to memorize contextual information from our environment. This contextual information can then be used to guide our attention to a specific location. Although the medial temporal lobe is important for this type of learning, the basal ganglia might also be involved considering its role in many

van Asselen, Marieke; Almeida, Ines; Andre, Rui; Januario, Cristina; Goncalves, Antonio Freire; Castelo-Branco, Miguel

2009-01-01

88

The corticostriatal projection: from synaptic plasticity to dysfunctions of the basal ganglia  

Microsoft Academic Search

Corticostriatal transmission has an important function in the regulation of the neuronal activity of the basal ganglia. The firing activity of corticostriatal neurones excites striatal cells via the release of glutamate. Presynaptic receptors that are located on corticostriatal terminals and that regulate the release of glutamate in the striatum have been postulated for dopamine and glutamate. Activation of these receptors

Paolo Calabresi; Antonio Pisani; Nicola B. Mercuri; Giorgio Bernardi

1996-01-01

89

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

ERIC Educational Resources Information Center

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

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

2006-01-01

90

The Basal Ganglia and Cortex Implement Optimal Decision Making Between Alternative Actions  

Microsoft Academic Search

Neurophysiological studies have identified a number of brain regions critically involved in solving the problem of action selection or decision making. In the case of highly practiced tasks, these regions include cortical areas hypothesized to integrate evidence supporting alternative actions and the basal ganglia, hypothesized to act as a central switch in gating behavioral requests. However, despite our relatively detailed

Rafal Bogacz; Kevin N. Gurney

2007-01-01

91

Dissociation between medial temporal lobe and basal ganglia memory systems in schizophrenia  

E-print Network

Dissociation between medial temporal lobe and basal ganglia memory systems in schizophrenia with schizophrenia. Acquired equivalence is a phenomenon in which prior training to treat two stimuli as equivalent generalization. Forty-three patients with DSM-IV schizophrenia and 28 matched healthy controls participated

Gluck, Mark

92

The prefrontallimbic network in depression: Modulation by hypothalamus, basal ganglia and midbrain  

Microsoft Academic Search

The anterior cingulate cortex, amygdala and hippocampus form part of an interconnected prefrontal neocortical and limbic archicortical network that is dysregulated in major depressive disorders (MDD). Modulation of this prefrontallimbic network (PLN) is principally through the hypothalamus, basal ganglia and midbrain. Here the likely mechanisms by which these modulations are affected are described and the implications of their failure for

M. R. Bennett

2011-01-01

93

Basal Ganglia-Thalamic Hemorrhage in Young Adults: A Hospital-Based Study  

Microsoft Academic Search

Background: The causes of basal ganglia-thalamic hemorrhage in the young are not well established. Therefore, its clinical profile, etiology, and risk factors were studied. Methods: Retrospectively, collected data were evaluated using the ?2 test and logistic regression analysis. Results: Gender differences occurred in the clinical profile, risk factors, and etiological spectrum. Large hematoma, Glasgow Coma Scale ?10 on admission, and

Yi-Chun Chen; Yih-Ru Wu; Wen-Chuin Hsu; Chiung-Mei Chen; Tsong-Hai Lee; Sien-Tsong Chen

2006-01-01

94

Bidirectional Plasticity in Striatonigral Synapses: A Switch to Balance Direct and Indirect Basal Ganglia Pathways  

ERIC Educational Resources Information Center

There is no hypothesis to explain how direct and indirect basal ganglia (BG) pathways interact to reach a balance during the learning of motor procedures. Both pathways converge in the substantia nigra pars reticulata (SNr) carrying the result of striatal processing. Unfortunately, the mechanisms that regulate synaptic plasticity in striatonigral

Aceves, Jose J.; Rueda-Orozco, Pavel E.; Hernandez-Martinez, Ricardo; Galarraga, Elvira; Bargas, Jose

2011-01-01

95

Basal Ganglia Atrophy in Prodromal Huntington's Disease Is Detectable Over One Year Using Automated Segmentation  

E-print Network

Basal Ganglia Atrophy in Prodromal Huntington's Disease Is Detectable Over One Year Using Automated disorders. VC 2011 Movement Disorder Society Key Words: Huntington's disease; prodromal HD; lon- gitudinal that modify the course of Huntington's disease (HD).1 For example, methods such as RNA interfer- ence have

Aron, Adam

96

Visuo-Motor and Cognitive Procedural Learning in Children with Basal Ganglia Pathology  

ERIC Educational Resources Information Center

We investigated procedural learning in 18 children with basal ganglia (BG) lesions or dysfunctions of various aetiologies, using a visuo-motor learning test, the Serial Reaction Time (SRT) task, and a cognitive learning test, the Probabilistic Classification Learning (PCL) task. We compared patients with early (less than 1 year old, n=9), later

Mayor-Dubois, C.; Maeder, P.; Zesiger, P.; Roulet-Perez, E.

2010-01-01

97

Subclinical Visuospatial Impairment in Parkinson's Disease: The Role of Basal Ganglia and Limbic System  

PubMed Central

Background: Visual perception deficits are a recurrent manifestation in Parkinsons disease (PD). Recently, structural abnormalities of fronto-parietal areas and subcortical regions, implicated in visual stimuli analysis, have been observed in PD patients with cognitive decline and visual hallucinations. The aim of the present study was to investigate the salient aspects of visual perception in cognitively unimpaired PD patients. Methods: Eleven right-handed non-demented right-sided onset PD patients without visuospatial impairment or hallucinations and 11 healthy controls were studied with functional magnetic resonance imaging while performing a specific visuoperceptual/visuospatial paradigm that allowed to highlight the specific process underlying visuospatial judgment. Results: Significant changes in both cortical areas and subcortical regions involved in visual stimuli processing were observed. In particular, PD patients showed a reduced activation for the right insula, left putamen, bilateral caudate, and right hippocampus, as well as an over-activation of the right dorso-lateral prefrontal and of the posterior parietal cortices, particularly in the right hemisphere. Conclusions: We found that both loss of efficiency and compensatory mechanisms occur in PD patients, providing further insight into the pathophysiological role of the functional alterations of basal ganglia and limbic structures in the impairment of visuoperceptual and visuospatial functions observed in PD. PMID:25157239

Caproni, Stefano; Muti, Marco; Di Renzo, Antonio; Principi, Massimo; Caputo, Nevia; Calabresi, Paolo; Tambasco, Nicola

2014-01-01

98

Functional properties of AMPA and NMDA receptors expressed in identified types of basal ganglia neurons.  

PubMed

AMPA- and NMDA-type glutamate receptors (AMPARs and NMDARs) mediate excitatory synaptic transmission in the basal ganglia and may contribute to excitotoxic injury. We investigated the functional properties of AMPARs and NMDARs expressed by six main types of basal ganglia neurons in acute rat brain slices (principal neurons and cholinergic interneurons of striatum, GABAergic and dopaminergic neurons of substantia nigra, globus pallidus neurons, and subthalamic nucleus neurons) using fast application of glutamate to nucleated and outside-out membrane patches. AMPARs in different types of basal ganglia neurons were functionally distinct. Those expressed in striatal principal neurons exhibited the slowest gating (desensitization time constant tau = 11.5 msec, 1 mM glutamate, 22 degrees C), whereas those in striatal cholinergic interneurons showed the fastest gating (desensitization time constant tau = 3.6 msec). The lowest Ca2+ permeability of AMPARs was observed in nigral dopaminergic neurons (PCa/PNa = 0.10), whereas the highest Ca2+ permeability was found in subthalamic nucleus neurons (PCa/PNa = 1.17). NMDARs of different types of basal ganglia neurons were less variable in their functional properties; those expressed in nigral dopaminergic neurons exhibited the slowest gating (deactivation time constant of predominant fast component tau1 = 150 msec, 100 microM glutamate), and those of globus pallidus neurons showed the fastest gating (tau1 = 67 msec). The Mg2+ block of NMDARs was similar; the average chord conductance ratio g-60mV/g+40mV was 0.18-0.22 in 100 microM external Mg2+. Hence, AMPARs expressed in different types of basal ganglia neurons are markedly diverse, whereas NMDARs are less variable in functional properties that are relevant for excitatory synaptic transmission and neuronal vulnerability. PMID:8987749

Gtz, T; Kraushaar, U; Geiger, J; Lbke, J; Berger, T; Jonas, P

1997-01-01

99

Decreased Basal Ganglia Activation in Subjects with Chronic Fatigue Syndrome: Association with Symptoms of Fatigue  

PubMed Central

Reduced basal ganglia function has been associated with fatigue in neurologic disorders, as well as in patients exposed to chronic immune stimulation. Patients with chronic fatigue syndrome (CFS) have been shown to exhibit symptoms suggestive of decreased basal ganglia function including psychomotor slowing, which in turn was correlated with fatigue. In addition, CFS patients have been found to exhibit increased markers of immune activation. In order to directly test the hypothesis of decreased basal ganglia function in CFS, we used functional magnetic resonance imaging to examine neural activation in the basal ganglia to a reward-processing (monetary gambling) task in a community sample of 59 male and female subjects, including 18 patients diagnosed with CFS according to 1994 CDC criteria and 41 non-fatigued healthy controls. For each subject, the average effect of winning vs. losing during the gambling task in regions of interest (ROI) corresponding to the caudate nucleus, putamen, and globus pallidus was extracted for group comparisons and correlational analyses. Compared to non-fatigued controls, patients with CFS exhibited significantly decreased activation in the right caudate (p?=?0.01) and right globus pallidus (p?=?0.02). Decreased activation in the right globus pallidus was significantly correlated with increased mental fatigue (r2?=?0.49, p?=?0.001), general fatigue (r2?=?0.34, p?=?0.01) and reduced activity (r2?=?0.29, p?=?0.02) as measured by the Multidimensional Fatigue Inventory. No such relationships were found in control subjects. These data suggest that symptoms of fatigue in CFS subjects were associated with reduced responsivity of the basal ganglia, possibly involving the disruption of projections from the globus pallidus to thalamic and cortical networks. PMID:24858857

Miller, Andrew H.; Jones, James F.; Drake, Daniel F.; Tian, Hao; Unger, Elizabeth R.; Pagnoni, Giuseppe

2014-01-01

100

Singing-Related Neural Activity Distinguishes Two Putative Pallidal Cell Types in the Songbird Basal Ganglia: Comparison to the Primate Internal and External Pallidal Segments  

E-print Network

The songbird area X is a basal ganglia homolog that contains two pallidal cell typeslocal neurons that project within the basal ganglia and output neurons that project to the thalamus. Based on these projections, it has ...

Goldberg, Jesse H.

101

Basal ganglia dopamine loss due to defect in purine recycling.  

PubMed

Several rare inherited disorders have provided valuable experiments of nature highlighting specific biological processes of particular importance to the survival or function of midbrain dopamine neurons. In both humans and mice, deficiency of hypoxanthine-guanine phosphoribosyl transferase (HPRT) is associated with profound loss of striatal dopamine, with relative preservation of other neurotransmitters. In the current studies of knockout mice, no morphological signs of abnormal development or degeneration were found in an exhaustive battery that included stereological and morphometric measures of midbrain dopamine neurons, electron microscopic studies of striatal axons and terminals, and stains for degeneration or gliosis. A novel culture model involving HPRT-deficient dopaminergic neurons also exhibited significant loss of dopamine without a morphological correlate. These results suggest that dopamine loss in HPRT deficiency has a biochemical rather than anatomical basis and imply that purine recycling to be a biochemical process of particular importance to the function of dopaminergic neurons. PMID:17374562

Egami, Kiyoshi; Yitta, Silaja; Kasim, Suhail; Lewers, J Chris; Roberts, Rosalinda C; Lehar, Mohamed; Jinnah, H A

2007-05-01

102

Endoscopic Evacuation of Basal Ganglia Hemorrhage via Keyhole Approach Using an Adjustable Cannula in Comparison with Craniotomy  

PubMed Central

Neuroendoscopic (NE) surgery as a minimal invasive treatment for basal ganglia hemorrhage is a promising approach. The present study aims to evaluate the efficacy and safety of NE approach using an adjustable cannula to treat basal ganglia hemorrhage. In this study, we analysed the clinical and radiographic outcomes between NE group (21 cases) and craniotomy group (30 cases). The results indicated that NE surgery might be an effective and safe approach for basal ganglia haemorrhage, and it is also suggested that NE approach may improve good functional recovery. However, NE approach only suits the selected patient, and the usefulness of NE approach needs further randomized controlled trials (RCTs) to evaluate. PMID:24949476

Zhang, Heng-Zhu; Li, Yu-Ping; Yan, Zheng-cun; Wang, Xing-dong; She, Lei; Wang, Xiao-dong; Dong, Lun

2014-01-01

103

Evidence for a causal inverse model in an avian cortico-basal ganglia circuit.  

PubMed

Learning by imitation is fundamental to both communication and social behavior and requires the conversion of complex, nonlinear sensory codes for perception into similarly complex motor codes for generating action. To understand the neural substrates underlying this conversion, we study sensorimotor transformations in songbird cortical output neurons of a basal-ganglia pathway involved in song learning. Despite the complexity of sensory and motor codes, we find a simple, temporally specific, causal correspondence between them. Sensory neural responses to song playback mirror motor-related activity recorded during singing, with a temporal offset of roughly 40 ms, in agreement with short feedback loop delays estimated using electrical and auditory stimulation. Such matching of mirroring offsets and loop delays is consistent with a recent Hebbian theory of motor learning and suggests that cortico-basal ganglia pathways could support motor control via causal inverse models that can invert the rich correspondence between motor exploration and sensory feedback. PMID:24711417

Giret, Nicolas; Kornfeld, Joergen; Ganguli, Surya; Hahnloser, Richard H R

2014-04-22

104

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

SciTech Connect

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

Akiyama, H.; Harrop, R.; McGeer, P.L.; Peppard, R.; McGeer, E.G.

1989-04-01

105

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

PubMed Central

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.

McMurtray, Aaron; Tseng, Ben; Diaz, Natalie; Chung, Julia; Mehta, Bijal; Saito, Erin

2014-01-01

106

Computational models of basal-ganglia pathway functions: focus on functional neuroanatomy  

PubMed Central

Over the past 15 years, computational models have had a considerable impact on basal-ganglia research. Most of these models implement multiple distinct basal-ganglia pathways and assume them to fulfill different functions. As there is now a multitude of different models, it has become complex to keep track of their various, sometimes just marginally different assumptions on pathway functions. Moreover, it has become a challenge to oversee to what extent individual assumptions are corroborated or challenged by empirical data. Focusing on computational, but also considering non-computational models, we review influential concepts of pathway functions and show to what extent they are compatible with or contradict each other. Moreover, we outline how empirical evidence favors or challenges specific model assumptions and propose experiments that allow testing assumptions against each other. PMID:24416002

Schroll, Henning; Hamker, Fred H.

2013-01-01

107

Evidence for a causal inverse model in an avian cortico-basal ganglia circuit  

PubMed Central

Learning by imitation is fundamental to both communication and social behavior and requires the conversion of complex, nonlinear sensory codes for perception into similarly complex motor codes for generating action. To understand the neural substrates underlying this conversion, we study sensorimotor transformations in songbird cortical output neurons of a basal-ganglia pathway involved in song learning. Despite the complexity of sensory and motor codes, we find a simple, temporally specific, causal correspondence between them. Sensory neural responses to song playback mirror motor-related activity recorded during singing, with a temporal offset of roughly 40 ms, in agreement with short feedback loop delays estimated using electrical and auditory stimulation. Such matching of mirroring offsets and loop delays is consistent with a recent Hebbian theory of motor learning and suggests that cortico-basal ganglia pathways could support motor control via causal inverse models that can invert the rich correspondence between motor exploration and sensory feedback. PMID:24711417

Giret, Nicolas; Kornfeld, Joergen; Ganguli, Surya; Hahnloser, Richard H. R.

2014-01-01

108

Role of synaptic integration of dopaminergic and cholinergic transmissions in basal ganglia function  

Microsoft Academic Search

Our studies concern the mechanisms of synaptic transmission and integration in the basal ganglia network, using immunotoxin-mediated cell targeting. We generated transgenic mice that expressed the human interleukin-2 receptor (hIL-2R)\\/GFP fusion protein under the control of the mGluR2 promoter. The immunotoxin that was composed of the monoclonal hIL-2R antibody fused to bacterial toxin was injected into the striatum. Immunotoxin injection

Shigetada Nakanishi; Satoshi Kaneko; Takatoshi Hikida; Dai Watanabe; Ira Pastan

2003-01-01

109

Processing of temporal information and the basal ganglia: new evidence from fMRI  

Microsoft Academic Search

. Temporal information processing is a fundamental brain function, which might include central timekeeping mechanisms independent\\u000a of sensory modality. Psychopharmacological and patient studies suggest a crucial role of the basal ganglia in time estimation.\\u000a In this study, functional magnetic resonance imaging (fMRI) was applied in 15 healthy right-handed male subjects performing\\u000a an auditory time estimation task (duration discrimination of tone

Igor Nenadic; Christian Gaser; Hans-Peter Volz; Thomas Rammsayer; Frank Hger; Heinrich Sauer

2003-01-01

110

Basal ganglia germinoma: Diagnostic value of MR spectroscopy and 11C-methionine positron emission tomography  

Microsoft Academic Search

We herein report a 12-year-old girl with a basal ganglia germinoma who presented with right-sided hemiparesis after a minor head trauma. Magnetic resonance (MR) imaging revealed a minimally enhanced lesion involving the left putamen, thalamus, and corona radiata. The lesion showed low-signal intensity on T1-, and high intensity on T2- and diffusion-weighted imaging. The MR signal in the adjacent globus

Yuji Fujii; Yoshiaki Saito; Toshihide Ogawa; Shinya Fujii; Hideki Kamitani; Shinji Kondo; Yasushi Horie; Masami Togawa; Michio Senda; Yoshihiro Maegaki; Kousaku Ohno

2008-01-01

111

Evidence for Altered Basal Ganglia-Brainstem Connections in Cervical Dystonia  

PubMed Central

Background There has been increasing interest in the interaction of the basal ganglia with the cerebellum and the brainstem in motor control and movement disorders. In addition, it has been suggested that these subcortical connections with the basal ganglia may help to coordinate a network of regions involved in mediating posture and stabilization. While studies in animal models support a role for this circuitry in the pathophysiology of the movement disorder dystonia, thus far, there is only indirect evidence for this in humans with dystonia. Methodology/Principal Findings In the current study we investigated probabilistic diffusion tractography in DYT1-negative patients with cervical dystonia and matched healthy control subjects, with the goal of showing that patients exhibit altered microstructure in the connectivity between the pallidum and brainstem. The brainstem regions investigated included nuclei that are known to exhibit strong connections with the cerebellum. We observed large clusters of tractography differences in patients relative to healthy controls, between the pallidum and the brainstem. Tractography was decreased in the left hemisphere and increased in the right hemisphere in patients, suggesting a potential basis for the left/right white matter asymmetry we previously observed in focal dystonia patients. Conclusions/Significance These findings support the hypothesis that connections between the basal ganglia and brainstem play a role in the pathophysiology of dystonia. PMID:22384048

Blood, Anne J.; Kuster, John K.; Woodman, Sandra C.; Kirlic, Namik; Makhlouf, Miriam L.; Multhaupt-Buell, Trisha J.; Makris, Nikos; Parent, Martin; Sudarsky, Lewis R.; Sjalander, Greta; Breiter, Henry

2012-01-01

112

Altered basal ganglia echogenicity early in sporadic Creutzfeldt-Jakob disease.  

PubMed

Creutzfeldt-Jakob disease (CJD) is a fatal neurodegenerative disease caused by conformational alteration of the ubiquitous prion protein. Sporadic CJD appears to progress faster if the basal ganglia are shown to be affected on magnetic resonance imaging. Transcranial B-mode sonography (TCS) enables visualization of differences in tissue echogenicity, which can be associated with changes in the cerebral metabolism of various metals. These metabolic changes are considered 1 of the potential mechanisms of the brain damage in CJD; TCS hyperechogenicity may reflect changes in metal homeostasis in CJD. We report a 63-year-old woman who presented with typical sporadic CJD. One month after she fell ill, a magnetic resonance imaging scan of her brain showed diffuse cortical but no obvious basal ganglia involvement. However, TCS revealed moderate hyperechogenicity of both lentiform nuclei. The patient's disease progressed quickly and she died 2 months later. TCS may show basal ganglia alteration early in the disease course of patients with quickly progressing CJD, thus aiding in premortem diagnosis. PMID:24674965

Veselinovic, Nikola; Pavlovic, Aleksandra M; Petrovic, Boris; Ristic, Aleksandar; Novakovic, Ivana; Svabic Medjedovic, Tamara; Pavlovic, Dragan; Sternic, Nada

2014-03-01

113

Hypomyelination with atrophy of the basal ganglia and cerebellum: further delineation of the phenotype and genotype-phenotype correlation.  

PubMed

Hypomyelination with atrophy of the basal ganglia and cerebellum is a rare leukoencephalopathy that was identified using magnetic resonance imaging in 2002. In 2013, whole exome sequencing of 11 patients with the disease revealed that they all had the same de novo mutation in TUBB4A, which encodes tubulin ?-4A. We investigated the mutation spectrum in a cohort of 42 patients and the relationship between genotype and phenotype. Patients were selected on the basis of clinical and magnetic resonance imaging abnormalities that are indicative of hypomyelination with atrophy of the basal ganglia and cerebellum. Genetic testing and a clinical inventory were performed, and sequential magnetic resonance images were evaluated using a standard protocol. The heterozygous TUBB4A mutation observed in the first 11 patients was the most common (25 patients). Additionally, 13 other heterozygous mutations were identified, located in different structural domains of tubulin ?-4A. We confirmed that the mutations were de novo in all but three patients. In two of these three cases we lacked parental DNA and in one the mutation was also found in the mother, most likely due to mosaicism. Patients showed a phenotypic continuum ranging from neonatal to childhood disease onset, normal to delayed early development and slow to more rapid neurological deterioration. Neurological symptomatology consisted of extrapyramidal movement abnormalities, spasticity, ataxia, cognitive deficit and sometimes epilepsy. Three patients died and the oldest living patient was 29 years of age. The patients' magnetic resonance images showed an absent or disappearing putamen, variable cerebellar atrophy and highly variable cerebral atrophy. Apart from hypomyelination, myelin loss was evident in several cases. Three severely affected patients had similar, somewhat atypical magnetic resonance image abnormalities. The study results were strongly suggestive of a genotype-phenotype correlation. The 25 patients with the common c.745G>A mutation generally had a less rapidly progressive disease course than the 17 cases with other TUBB4A mutations. Overall, this work demonstrates that the distinctive magnetic resonance imaging pattern for hypomyelination with atrophy of the basal ganglia and cerebellum defines a homogeneous clinical phenotype of variable severity. Patients almost invariably have prominent extrapyramidal movement abnormalities, which are rarely seen in patients with hypomyelination of different origin. A dominant TUBB4A mutation is also associated with dystonia type 4, in which magnetic resonance images of the brain seem normal. It is highly likely that there is a disease continuum associated with TUBB4A mutations, of which hypomyelination with atrophy of the basal ganglia and cerebellum and dystonia type 4 are the extremes. This would indicate that extrapyramidal movement abnormalities constitute the core feature of the disease spectrum related to dominant TUBB4A mutations and that all other features are variable. PMID:24785942

Hamilton, Eline M; Polder, Emiel; Vanderver, Adeline; Naidu, Sakkubai; Schiffmann, Raphael; Fisher, Kate; Ragu, Ana Boban; Blumkin, Luba; van Berkel, Carola G M; Waisfisz, Quinten; Simons, Cas; Taft, Ryan J; Abbink, Truus E M; Wolf, Nicole I; van der Knaap, Marjo S

2014-07-01

114

Using point process models to determine the impact of visual cues on basal ganglia activity and behavior of Parkinson's patients  

E-print Network

Deep brain stimulation is an effective therapy for Parkinson's disease (PD) that has enabled microelectrode recordings from single-unit cells in the sub-thalamic nucleus (STN) of the basal ganglia. This rare data is important ...

Brown, Emery N.

115

Connections of the basal ganglia with the limbic system: implications for neuromodulation therapies of anxiety and affective disorders  

Microsoft Academic Search

The basal ganglia are best known for their role in motor planning and execution. However, it is currently widely accepted\\u000a that they are also involved in cognitive and emotional behaviors. Parts of the basal ganglia play a key role in reward and\\u000a reinforcement, addictive behaviors and habit formation. Pathophysiological processes underlying psychiatric disorders such\\u000a as depression, obsessive compulsive disorder and

P. Stathis; I. G. Panourias; M. S. Themistocleous; Damianos E. Sakas

116

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

PubMed Central

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

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

2013-01-01

117

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

PubMed

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

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

2013-09-01

118

Dyskinesia associated with hyperglycemia and basal ganglia hyperintensity: report of a rare diabetic complication.  

PubMed

The syndrome of dyskinesia associated with hyperglycemia and basal ganglia hyperintensity on T1 - weighted MR images is rare and most often affects elderly patients with type 2 diabetes. We report a case of a 79year-old female patient who presented to the ED with a 12h history of a left sided hemichoreoathetosis. Laboratory results revealed pronounced nonketotic hyperglycemia [27mmol/L (486mg/dL); HbA1c 140mmol/mol (15%)] and brain MRI showed bilateral T1 hyperintensity in the basal ganglia, more noticeable on the right side. One week before she had been admitted with a diagnosis of transient ischemic attack consisting in left hemiparesthesia, also with nonketotic hyperglycemia [38.9mmol/L (700mg/dL)] and was discharged home with partial correction of her metabolic disturbance. The movement disorder did not improve with adequate glycemic control so haloperidol was started. Six weeks later she was seen on an outpatient basis. She still had minimal residual involuntary movements of the left arm and leg. Laboratory exams revealed a well controlled diabetes mellitus [glycemia 6.0mmol/L (109mg/dL), HbA1c 57mmol/mol (7.4%)]. In conclusion, the syndrome of dyskinesia associated to hyperglycemia and hyperintensity in the basal ganglia on T1 - weighted MR images is a rare, intriguing and yet incompletely understood complication of diabetes mellitus. The increasing number of reported cases may help to better understand its peculiarities such as the existence of a clear clinical radiological dissociation and to unveil pathophysiological aspects. We suggest the possibility that the metabolic disturbances unmask a previous established asymptomatic striatum vasculopathy. PMID:23154926

Taboada, Giselle F; Lima, Giovanna A B; Castro, Jos E C; Liberato, Bernardo

2013-03-01

119

Rhythmic Cortical Neurons Increase their Oscillations and Sculpt Basal Ganglia Signaling During Motor Learning  

PubMed Central

The function and modulation of neural circuits underlying motor skill may involve rhythmic oscillations (Feller, 1999; Marder and Goaillard, 2006; Churchland et al., 2012). In the proposed pattern generator for birdsong, the cortical nucleus HVC, the frequency and power of oscillatory bursting during singing increases with development (Crandall et al., 2007; Day et al., 2009). We examined the maturation of cellular activity patterns that underlie these changes. Single unit ensemble recording combined with antidromic identification (Day et al., 2011) was used to study network development in anesthetized zebra finches. Autocovariance quantified oscillations within single units. A subset of neurons oscillated in the theta/alpha/mu/beta range (820 Hz), with greater power in adults compared to juveniles. Across the network, the normalized oscillatory power in the 820 Hz range was greater in adults than juveniles. In addition, the correlated activity between rhythmic neuron pairs increased with development. We next examined the functional impact of the oscillators on the output neurons of HVC. We found that the firing of oscillatory neurons negatively correlated with the activity of cortico-basal ganglia neurons (HVCXs), which project to Area X (the song basal ganglia). If groups of oscillators work together to tonically inhibit and precisely control the spike timing of adult HVCXs with coordinated release from inhibition, then the activity of HVCXs in juveniles should be decreased relative to adults due to uncorrelated, tonic inhibition. Consistent with this hypothesis, HVCXs had lower activity in juveniles. These data reveal network changes that shape cortical-to-basal ganglia signaling during motor learning. PMID:23776169

Day, Nancy F.; Nick, Teresa A.

2014-01-01

120

The basal ganglia in perceptual timing: Timing performance in Multiple System Atrophy and Huntington's disease?  

PubMed Central

The timing of perceptual events depends on an anatomically and functionally connected network comprising basal ganglia, cerebellum, pre-frontal cortex and supplementary motor area. Recent studies demonstrate the cerebellum to be involved in absolute, duration-based timing, but not in relative timing based on a regular beat. Conversely, functional involvement of the striatum is observed in relative timing, but its role in absolute timing is unclear. This work tests the specific role of the basal ganglia in the perceptual timing of auditory events. It aims to distinguish the hypothesised unified model of time perception (Teki, Grube, & Griffiths, 2012), in which the striatum is a mandatory component for all timing tasks, from a modular system in which they subserve relative timing, with absolute timing processed by the cerebellum. Test groups comprised individuals with Multiple System Atrophy, a disorder in which similar pathology can produce clinical deficits associated with dysfunction of the cerebellum (MSA-C, n=8) or striatum (MSA-P, n=10), and early symptomatic Huntington's disease (HD, n=14). Individuals with chronic autoimmune peripheral neuropathy (n=11) acted as controls. Six adaptive tasks were carried out to assess perceptual thresholds for absolute timing through duration discrimination for sub- and supra-second time intervals, and relative timing through the detection of beat-based regularity and irregularity, detection of a delay within an isochronous sequence, and the discrimination of sequences with metrical structure. All three patient groups exhibited impairments in performance in comparison with the control group for all tasks, and severity of impairment was significantly correlated with disease progression. No differences were demonstrated between MSA-C and MSA-P, and the most severe impairments were observed in those with HD. The data support an obligatory role for the basal ganglia in all tested timing tasks, both absolute and relative, as predicted by the unified model. The results are not compatible with models of a brain timing network based upon independent modules. PMID:24135486

Cope, Thomas E.; Grube, Manon; Singh, Baldev; Burn, David J.; Griffiths, Timothy D.

2014-01-01

121

Role of the basal ganglia in the control of sleep and wakefulness  

PubMed Central

The basal ganglia (BG) act as a cohesive functional unit that regulates motor function, habit formation, and reward/addictive behaviors; but the debate has only recently started on how the BG maintain wakefulness and suppress sleep to achieve all these fundamental functions of the BG. Neurotoxic lesioning, pharmacological approaches, and the behavioral analyses of genetically modified animals revealed that the striatum and globus pallidus are important for the control of sleep and wakefulness. Here, we discuss anatomical and molecular mechanisms for sleep-wake regulation in the BG and propose a plausible model in which the nucleus accumbens integrates behavioral processes with wakefulness through adenosine and dopamine receptors. PMID:23465424

Lazarus, Michael; Chen, Jiang-Fan; Urade, Yoshihiro; Huang, Zhi-Li

2013-01-01

122

Functional correlates of exaggerated oscillatory activity in basal ganglia output in hemiparkinsonian rats.  

PubMed

Exaggerated beta range (13-30Hz) synchronized activity is observed in the basal ganglia of Parkinson's disease (PD) patients during implantation of deep brain stimulation electrodes and is thought to contribute to the motor symptoms of this disorder. To explore the translational potential of similar activity observed in a rat model of PD, local field potentials (LFPs) and spiking activity in basal ganglia output were characterized in rats with unilateral dopamine cell lesion during a range of behaviors. A circular treadmill was used to assess activity during walking; hemiparkinsonian rats could maintain a steady gait when oriented ipsiversive to the lesioned hemisphere, but were less effective at walking when oriented contraversive to lesion. Dramatic increases in substantia nigra pars reticulata (SNpr) LFP oscillatory activity and spike-LFP synchronization were observed within the beta/low gamma range (12-40Hz) in the lesioned hemisphere, relative to the non-lesioned hemisphere, with the dominant frequency of spike-LFP entrainment and LFP power varying with behavioral state. At 3weeks postlesion, the mean dominant entrainment frequency during ipsiversive treadmill walking and grooming was 34Hz. Other behaviors were associated with lower mean entrainment frequencies: 27-28Hz during alert non-walking and REM, 17Hz during rest and 21Hz during urethane anesthesia with sensory stimulation. SNpr spike-LFP entrainment frequency was stable during individual treadmill walking epochs, but increased gradually over weeks postlesion. In contrast, SNpr LFP power in the 25-40Hz range was greatest at the initiation of each walking epoch, and decreased during walking to stabilize by 6min at 49% of initial values. Power was further modulated in conjunction with the 1.5s stepping rhythm. Administration of l-dopa improved contraversive treadmill walking in correlation with a reduction in SNpr 25-40Hz LFP power and spike synchronization in the dopamine cell lesioned hemisphere. These effects were reversed by the serotonergic 1A agonist, 8-OH-DPAT. While the prominent spike-LFP phase locking observed during ongoing motor activity in the hemiparkinsonian rats occurs at frequencies intriguingly higher than in PD patients, the synchronized activity in the SNpr of this animal model has much in common with oscillatory activity recorded from the basal ganglia of the PD patients. Results support the potential of this model for providing insight into relationships between synchronization of basal ganglia output induced by loss of dopamine and motor symptoms in PD. PMID:25084518

Brazhnik, Elena; Novikov, Nikolay; McCoy, Alex J; Cruz, Ana V; Walters, Judith R

2014-11-01

123

Basal ganglia and kinematics modulation: insights from Parkinson's and Huntington's diseases.  

PubMed

Movement kinematic variables related to force production can be modulated to respond appropriately to different contexts. We previously showed that in a choice-reaction time and a predictable timed-response task, normal subjects perform reaching movements to the same targets with two different kinematic patterns, a marker of flexibility. Here, we used the two tasks to determine whether basal ganglia are involved in the selection and modulation of movement kinematics and therefore in flexible force production. We tested seventeen patients in the early stages of Parkinson's disease, eleven pre-symptomatic Huntington's disease carriers and sixteen age-matched normal controls with the above-mentioned motor tasks. In both patient groups, the difference in kinematics (movement duration, peak velocity and acceleration) between the two tasks was significantly reduced compared to controls, indicating a limited range of choices or flexibility. However, this reduction was skewed in opposite directions in the two disorders, with force production being generally higher in Huntington's carriers and lower in Parkinson's patients compared to controls. We conclude that basal ganglia are involved in adapting movement to different contexts and selecting the appropriate movement force. The opposite trends in Parkinson's and Huntington's disease suggest that such regulation might depend on the balance between the outputs of direct and indirect pathways. PMID:21764625

Moisello, Clara; Perfetti, Bernardo; Marinelli, Lucio; Sanguineti, Vittorio; Bove, Marco; Feigin, Andrew; Di Rocco, Alessandro; Eidelberg, David; Ghilardi, M F

2011-09-01

124

Increase of glucose consumption in basal ganglia, thalamus and frontal cortex of patients with spasmodic torticollis  

SciTech Connect

The pathophysiology of spasmodic torticollis, a focal dystonia involving neck muscles, is still unclear. Positron emission tomography (PET) studies showed either an increase as well as a decrease of regional cerebral metabolic rate of glucose (rCMRglu) in basal ganglia. In the present study, [18F]FDG and PET was used to measure rCMRglu in 10 patients with spasmodic torticollis (mean age 50.37 {plus_minus} 11.47) and 10 age matched controls. All cases with a short disease duration, were untreated. A factorial analysis of variance revealed a significant bilateral increase of glucose consumption in caudate nucleus and pallidum/putamen complex (p>0.004) and in the cerebellum (p>0.001). The rCMRglu increase in the motor/premotor cortex and in the thalamus reached a trend towards significance (p<0.05). These preliminary data show enhanced metabolism in basal ganglia and cerebellum as the functional correlate of focal dystonia. A recently proposed model suggests that dystonia would be the consequence of a putaminal hyperactivity, leading to the breakdown of the pallidal inhibitory control on thalamus and thalamo-cortical projections.

Grassi, F.; Bressi, S.; Antoni, M. [Univ. of Milan (Italy)] [and others

1994-05-01

125

Germinoma originating in the basal ganglia and thalamus: MR and CT evaluation  

SciTech Connect

Purpose: to describe MR and CT features of germinoma originating in the basal ganglia and thalamus and to discuss the roles of each modality for its diagnosis. Methods: MR and CT studies of six cases of germinomas, five of which were histologically proved, were retrospectively reviewed. T1-weighted, T2-weighted, and contrast-enhanced T1-weighted conventional spin-echo images, and unenhanced and contrast-enhanced CT images were evaluated. Results: Typically, the tumor consisted of an irregular solid area with contrast enhancement and various-size cysts. Cystic components were found in five cases and calcification in four. Intratumoral hemorrhage was noted in one. Ipsilateral cerebral hemiatrophy and brain stem hemiatrophy were noted in three cases each. MR was superior to CT in evaluating precise tumor extension, cystic components, and intratumoral hemorrhage, although in one case, extension of the tumor was better defined on CT in its early stage. Calcification was difficult to identify by MR alone. The solid components of the tumors generally showed slightly high density on CT, which seemed to be characteristic compared with nonspecific intensity pattern on MR. Conclusion: The combination of CT and MR findings allows early detection and appropriate diagnosis of the mass in the basal ganglia and/or thalamus. 26 refs., 4 figs., 1 tab.

Shuichi Higano; Shoki Takahashi; Kiyoshi Ishii [Tohoku Univ. School of Medicine (Japan)

1994-09-01

126

Mutations in SLC20A2 are a major cause of familial idiopathic basal ganglia calcification  

PubMed Central

Familial idiopathic basal ganglia calcification (IBGC) or Fahrs disease is a rare neurodegenerative disorder characterized by calcium deposits in the basal ganglia and other brain regions, which is associated with neuropsychiatric and motor symptoms. Familial IBGC is genetically heterogeneous and typically transmitted in an autosomal dominant fashion. We performed a mutational analysis of SLC20A2, the first gene found to cause IBGC, to assess its genetic contribution to familial IBGC. We recruited 218 subjects from 29 IBGC-affected families of varied ancestry and collected medical history, neurological exam, and head CT scans to characterize each patients disease status. We screened our patient cohort for mutations in SLC20A2. Twelve novel (nonsense, deletions, missense, and splice site) potentially pathogenic variants, one synonymous variant, and one previously reported mutation were identified in 13 families. Variants predicted to be deleterious cosegregated with disease in five families. Three families showed nonsegregation with clinical disease of such variants, but retrospective review of clinical and neuroimaging data strongly suggested previous misclassification. Overall, mutations in SLC20A2 account for as many as 41 % of our familial IBGC cases. Our screen in a large series expands the catalog of SLC20A2 mutations identified to date and demonstrates that mutations in SLC20A2 are a major cause of familial IBGC. Non-perfect segregation patterns of predicted deleterious variants highlight the challenges of phenotypic assessment in this condition with highly variable clinical presentation. PMID:23334463

Hsu, Sandy Chan; Sears, Renee L.; Lemos, Roberta R.; Quintns, Beatriz; Huang, Alden; Spiteri, Elizabeth; Nevarez, Lisette; Mamah, Catherine; Zatz, Mayana; Pierce, Kerrie D.; Fullerton, Janice M.; Adair, John C.; Berner, Jon E.; Bower, Matthew; Brodaty, Henry; Carmona, Olga; Dobrici?, Valerija; Fogel, Brent L.; Garca-Estevez, Daniel; Goldman, Jill; Goudreau, John L.; Hopfer, Suellen; Jankovi?, Milena; Jaum, Serge; Jen, Joanna C.; Kirdlarp, Suppachok; Klepper, Joerg; Kosti?, Vladimir; Lang, Anthony E.; Linglart, Agns; Maisenbacher, Melissa K.; Manyam, Bala V.; Mazzoni, Pietro; Miedzybrodzka, Zofia; Mitarnun, Witoon; Mitchell, Philip B.; Mueller, Jennifer; Novakovi?, Ivana; Paucar, Martin; Paulson, Henry; Simpson, Sheila A.; Svenningsson, Per; Tuite, Paul; Vitek, Jerrold; Wetchaphanphesat, Suppachok; Williams, Charles; Yang, Michele; Schofield, Peter R.; de Oliveira, Joo R. M.; Sobrido, Mara-Jess

2014-01-01

127

Cortical-basal ganglia imbalance in schizophrenia patients and unaffected first-degree relatives.  

PubMed

Structural brain changes are amongst the most robust biological alterations in schizophrenia, and their investigation in unaffected relatives is important for an assessment of the contribution of genetic factors. In this cross-sectional morphometry study we investigated whether volume changes in SZ are linked with genetic vulnerability and whether these effects are separated from secondary illness effects. We compared density of grey and white matter using high-resolution 3D-anatomical MRI imaging data in 31 SZ patients, 29 first-degree relatives and 38 matched healthy controls, using Voxel-Based Morphometry (VBM) with SPM8. Volume of basal ganglia was also compared by manual segmentation. We found increased grey matter in the striatum, globus pallidus internus and thalamus and decreased grey matter in the parahippocampal and cingulate gyri both in SZ patients and relatives. Additionally, SZ patients had decreased volume of temporal, frontal and limbic grey and white matter in comparison with relatives and controls. Relatives showed intermediate values in many of these areas. Increased volume in the thalamus and parts of the basal ganglia and decreased volume of cortical areas and underlying white matter were thus associated with schizophrenia and its genetic vulnerability. These results suggest that brain morphological changes associated with SZ are in part determined by genetic risk factors and are not entirely explained by effects of medication or changes secondary to illness. PMID:22464726

Oertel-Knchel, V; Knchel, C; Matura, S; Rotarska-Jagiela, A; Magerkurth, J; Prvulovic, D; Haenschel, C; Hampel, H; Linden, D E J

2012-07-01

128

An Interactive Channel Model of the Basal Ganglia: Bifurcation Analysis Under Healthy and Parkinsonian Conditions  

PubMed Central

Oscillations in the basal ganglia are an active area of research and have been shown to relate to the hypokinetic motor symptoms of Parkinsons disease. We study oscillations in a multi-channel mean field model, where each channel consists of an interconnected pair of subthalamic nucleus and globus pallidus sub-populations. To study how the channels interact, we perform two-dimensional bifurcation analysis of a model of an individual channel, which reveals the critical boundaries in parameter space that separate different dynamical modes; these modes include steady-state, oscillatory, and bi-stable behaviour. Without self-excitation in the subthalamic nucleus a single channel cannot generate oscillations, yet there is little experimental evidence for such self-excitation. Our results show that the interactive channel model with coupling via pallidal sub-populations demonstrates robust oscillatory behaviour without subthalamic self-excitation, provided the coupling is sufficiently strong. We study the model under healthy and Parkinsonian conditions and demonstrate that it exhibits oscillations for a much wider range of parameters in the Parkinsonian case. In the discussion, we show how our results compare with experimental findings and discuss their possible physiological interpretation. For example, experiments have found that increased lateral coupling in the rat basal ganglia is correlated with oscillations under Parkinsonian conditions. PMID:23945348

2013-01-01

129

Molecular microcircuitry underlies functional specification in a basal ganglia circuit dedicated to vocal learning  

PubMed Central

Summary Similarities between speech and birdsong make songbirds advantageous for investigating the neurogenetics of learned vocal communication; a complex phenotype likely supported by ensembles of interacting genes in cortico-basal ganglia pathways of both species. To date, only FoxP2 has been identified as critical to both speech and birdsong. We performed weighted gene co-expression network analysis on microarray data from singing zebra finches to discover gene ensembles regulated during vocal behavior. We found ~2,000 singing-regulated genes comprising 3 co-expression groups unique to area X, the basal ganglia subregion dedicated to learned vocalizations. These contained known targets of human FOXP2 and potential avian targets. We validated novel biological pathways for vocalization. Higher order gene co-expression patterns, rather than expression levels, molecularly distinguish area X from the ventral striato-pallidum during singing. The previously unknown structure of singing-driven networks enables prioritization of molecular interactors that likely bear on human motor disorders, especially those affecting speech. PMID:22325205

Hilliard, Austin T.; Miller, Julie E.; Fraley, Elizabeth; Horvath, Steve; White, Stephanie A.

2012-01-01

130

[A case of large basal ganglia AVM totally removed by staged operation].  

PubMed

Large basal ganglia AVMs have been deemed inoperable because of their location in critical structures. Nonetheless, the unfavorable natural history of an untreated ruptured AVM in a young patient induced us to approach these lesions. We presented a case of a large basal ganglia AVM totally removed by a three-staged operation. A 26-year-old man who had twice experienced intracranial hemorrhage was admitted for examination. On admission, mild left hemiparesis, hypesthesia and left hemianopsia were disclosed. CT scan showed the AVM was located in the posterior thalamus with the hematoma cavity laterally. Right carotid and vertebral angiograms demonstrated a large AVM, 5cm in diameter, supplied by the anterior choroidal artery (AchoA), the lateral lenticulostriate arteries (I-LSAs), the lateral posterior choroidal artery (LPchoA) and the thalamo-perforating artery. Drainage was via the internal cerebral vein and the basal vein of Rosenthal. MRI demonstrated more clearly the anatomical relationship of the nidus and surrounding structures. The patient underwent a three staged operation. At the first operation AchoA was interrupted in the inferior horn of the lateral ventricle (IHL) via the hematoma cavity using the trans-sylvian approach. The anterior part of the nidus was dissected with all except one of the I-LSAs being disconnected. At the next operation by occipital interhemispheric approach, some feeders from the posterior cerebral artery were coagulated and disconnected. The medial and posterior part of the nidus was dissected from the thalamus along with the choroid plexus of the trigone of the lateral ventricle.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2234310

Tsutsumi, K; Shiokawa, Y; Kubota, M; Aoki, N; Mizutani, H

1990-09-01

131

A cortical motor nucleus drives the basal ganglia-recipient thalamus in singing birds  

PubMed Central

The pallido-recipient thalamus transmits information from the basal ganglia (BG) to the cortex and plays a critical role motor initiation and learning. Thalamic activity is strongly inhibited by pallidal inputs from the BG, but the role of non-pallidal inputs, such as excitatory inputs from cortex, is unclear. We have recorded simultaneously from presynaptic pallidal axon terminals and postsynaptic thalamocortical neurons in a BG-recipient thalamic nucleus necessary for vocal variability and learning in zebra finches. We found that song-locked rate modulations in the thalamus could not be explained by pallidal inputs alone, and persisted following pallidal lesion. Instead, thalamic activity was likely driven by inputs from a motor cortical nucleus also necessary for singing. These findings suggest a role for cortical inputs to the pallido-recipient thalamus in driving premotor signals important for exploratory behavior and learning. PMID:22327474

Goldberg, Jesse H.

2012-01-01

132

Hereditary haemochromatosis: a case of iron accumulation in the basal ganglia associated with a parkinsonian syndrome.  

PubMed Central

Hereditary haemochromatosis is characterised by excessive parenchymal iron deposition, particularly in the liver. Usually hereditary haemochromatosis is not associated with neurological symptoms and iron deposition in the brain has not previously been described as a pathological phenomenon. A patient is reported with hereditary haemochromatosis and a syndrome of dementia, dysarthria, a slowly progressive gait disturbance, imbalance, muscle weakness, rigidity, bradykinesia, tremor, ataxia, and dyssynergia. The findings on MRI of a large signal decrease in the basal ganglia, consistent with excessive iron accumulation, indicate a causal relation to the symptoms. Although the neurological symptoms did not improve in our patient, hereditary haemochromatosis should be considered in the differential diagnosis of parkinsonian syndromes, because complications of iron induced organ injury may be prevented by phlebotomy. Images PMID:7673967

Nielsen, J E; Jensen, L N; Krabbe, K

1995-01-01

133

Limb apraxia in patients with damage confined to the left basal ganglia and thalamus.  

PubMed Central

Limb apraxia was investigated with standardised tests in 14 patients whose CT scan provided evidence of a vascular lesion confined to the left basal ganglia, or the thalamus, or both, and not involving the cortex or adjacent white matter. Five patients were severely impaired in imitating movements and pantomiming object use. Four of them also performed poorly when tested with real objects. In two patients the lesion was primarily thalamic and in three the lesion was primarily in the lenticular nucleus and the posterior limb of the internal capsule. Patients without apraxia generally had smaller injuries, but there were exceptions. Apraxia is currently conceived of as due to damage of cortical areas and their cortico-cortical connections, but the present data suggest that the model should be enlarged to include the deep nuclei and the pathways running through them. Images PMID:3760891

De Renzi, E; Faglioni, P; Scarpa, M; Crisi, G

1986-01-01

134

Learning to Select Actions with Spiking Neurons in the Basal Ganglia  

PubMed Central

We expand our existing spiking neuron model of decision making in the cortex and basal ganglia to include local learning on the synaptic connections between the cortex and striatum, modulated by a dopaminergic reward signal. We then compare this model to animal data in the bandit task, which is used to test rodent learning in conditions involving forced choice under rewards. Our results indicate a good match in terms of both behavioral learning results and spike patterns in the ventral striatum. The model successfully generalizes to learning the utilities of multiple actions, and can learn to choose different actions in different states. The purpose of our model is to provide both high-level behavioral predictions and low-level spike timing predictions while respecting known neurophysiology and neuroanatomy. PMID:22319465

Stewart, Terrence C.; Bekolay, Trevor; Eliasmith, Chris

2012-01-01

135

Movement disorders in astrocytomas of the basal ganglia and the thalamus.  

PubMed Central

In a series of 225 patients with astrocytomas (grades I-IV) of the basal ganglia and the thalamus, 20 had a movement disorder. In all patients the histological diagnosis was verified by stereotactic biopsy. Tremor was observed in twelve patients, dystonia in eight, chorea in three, and chorea/ballismus and myoclonus in one. The tumour involved the thalamus in 16 patients. Corticospinal tract dysfunction was evident in 70% of the patients with movement disorders and in 73% of those without. Demographic, clinical, histological and neuroradiological data of the patients with a movement disorder were compared with the data of patients without. CT data yielded no differences with respect to the involvement of anatomical structures. Movement disorders were significantly associated with low-grade astrocytomas. Images PMID:1479396

Krauss, J K; Nobbe, F; Wakhloo, A K; Mohadjer, M; Vach, W; Mundinger, F

1992-01-01

136

The highs and lows of beta activity in cortico-basal ganglia loops.  

PubMed

Oscillatory activity in the beta (13-30Hz) frequency band is widespread in cortico-basal ganglia circuits, and becomes prominent in Parkinson's disease (PD). Here we develop the hypothesis that the degree of synchronization in this frequency band is a critical factor in gating computation across a population of neurons, with increases in beta band synchrony entailing a loss of information-coding space and hence computational capacity. Task and context drive this dynamic gating, so that for each state there will be an optimal level of network synchrony, and levels lower or higher than this will impair behavioural performance. Thus, both the pathological exaggeration of synchrony, as observed in PD, and the ability of interventions like deep brain stimulation (DBS) to excessively suppress synchrony can potentially lead to impairments in behavioural performance. Indeed, under physiological conditions, the manipulation of computational capacity by beta activity may itself present a mechanism of action selection and maintenance. PMID:24890470

Brittain, John-Stuart; Sharott, Andrew; Brown, Peter

2014-06-01

137

The basal ganglia is necessary for learning spectral, but not temporal features of birdsong  

PubMed Central

Executing a motor skill requires the brain to control which muscles to activate at what times. How these aspects of control - motor implementation and timing - are acquired, and whether the learning processes underlying them differ, is not well understood. To address this we used a reinforcement learning paradigm to independently manipulate both spectral and temporal features of birdsong, a complex learned motor sequence, while recording and perturbing activity in underlying circuits. Our results uncovered a striking dissociation in how neural circuits underlie learning in the two domains. The basal ganglia was required for modifying spectral, but not temporal structure. This functional dissociation extended to the descending motor pathway, where recordings from a premotor cortex analogue nucleus reflected changes to temporal, but not spectral structure. Our results reveal a strategy in which the nervous system employs different and largely independent circuits to learn distinct aspects of a motor skill. PMID:24075977

Ali, Farhan; Fantana, Antoniu L.; Burak, Yoram; Olveczky, Bence P.

2013-01-01

138

Efferent connections of the "olfactostriatum": a specialized vomeronasal structure within the basal ganglia of snakes.  

PubMed

The olfactostriatum is a portion of the basal ganglia of snakes that receives substantial vomeronasal afferents through projections from the nucleus sphericus. In a preceding article, the olfactostriatum of garter snakes (Thamnophis sirtalis) was characterized on the basis of chemoarchitecture (distribution of serotonin, neuropeptide Y and tyrosine hydroxylase) and pattern of afferent connections [Martinez-Marcos, A., Ubeda-Banon, I., Lanuza, E., Halpern, M., 2005. Chemoarchitecture and afferent connections of the "olfactostriatum": a specialized vomeronasal structure within the basal ganglia of snakes. J. Chem. Neuroanat. 29, 49-69]. In the present study, its efferent connections have been investigated. The olfactostriatum projects to the main and accessory olfactory bulbs, lateral cortex, septal complex, ventral pallidum, external, ventral anterior and dorsolateral amygdalae, bed nucleus of the stria terminalis, preoptic area, lateral posterior hypothalamic nucleus, ventral tegmental area, substantia nigra and raphe nuclei. Tracer injections in the nucleus accumbens proper, a structure closely associated with the olfactostriatum, result in a similar pattern of efferent connections with the exception of those reaching the main and accessory olfactory bulbs, lateral cortex, external, ventral anterior and dorsolateral amygdalae and bed nucleus of the stria terminalis. These data, therefore, help to characterize the olfactostriatum, an apparently specialized area of the nucleus accumbens. Double labeling experiments after tracer injections in the nucleus sphericus and the lateral posterior hypothalamic nucleus demonstrate a pathway between these two structures through the olfactostriatum. Injections in the olfactostriatum and in the medial amygdala show parallel projections to the lateral posterior hypothalamic nucleus. Since this hypothalamic nucleus has been previously described as projecting to the hypoglossal nucleus, both, the medial amygdala and the olfactostriatum may mediate vomeronasal influence on tongue-flick behavior. PMID:15820623

Martinez-Marcos, Alino; Ubeda-Baon, Isabel; Lanuza, Enrique; Halpern, Mimi

2005-05-01

139

Distinct Neurogenomic States in Basal Ganglia Subregions Relate Differently to Singing Behavior in Songbirds  

PubMed Central

Both avian and mammalian basal ganglia are involved in voluntary motor control. In birds, such movements include hopping, perching and flying. Two organizational features that distinguish the songbird basal ganglia are that striatal and pallidal neurons are intermingled, and that neurons dedicated to vocal-motor function are clustered together in a dense cell group known as area X that sits within the surrounding striato-pallidum. This specification allowed us to perform molecular profiling of two striato-pallidal subregions, comparing transcriptional patterns in tissue dedicated to vocal-motor function (area X) to those in tissue that contains similar cell types but supports non-vocal behaviors: the striato-pallidum ventral to area X (VSP), our focus here. Since any behavior is likely underpinned by the coordinated actions of many molecules, we constructed gene co-expression networks from microarray data to study large-scale transcriptional patterns in both subregions. Our goal was to investigate any relationship between VSP network structure and singing and identify gene co-expression groups, or modules, found in the VSP but not area X. We observed mild, but surprising, relationships between VSP modules and song spectral features, and found a group of four VSP modules that were highly specific to the region. These modules were unrelated to singing, but were composed of genes involved in many of the same biological processes as those we previously observed in area X-specific singing-related modules. The VSP-specific modules were also enriched for processes disrupted in Parkinson's and Huntington's Diseases. Our results suggest that the activation/inhibition of a single pathway is not sufficient to functionally specify area X versus the VSP and support the notion that molecular processes are not in and of themselves specialized for behavior. Instead, unique interactions between molecular pathways create functional specificity in particular brain regions during distinct behavioral states. PMID:23144607

Hilliard, Austin T.; Miller, Julie E.; Horvath, Steve; White, Stephanie A.

2012-01-01

140

Creative cognition and the brain: dissociations between frontal, parietal-temporal and basal ganglia groups.  

PubMed

The objective of the study was to investigate creativity in relation to brain function by assessing creative thinking in various neurological populations. Several measures were employed to assess different facets of creative thinking in clinical groups with frontal lobe, basal ganglia or parietal-temporal lesions relative to matched healthy control participants. The frontal group was subdivided into frontolateral, frontopolar and frontal-extensive groups. Hierarchical regression analyses were employed to assess the significance levels associated with the effects after accounting for IQ differences between the groups. Findings were only considered noteworthy if they at least suggested the presence of a strong trend and were accompanied by medium to large effect sizes. The parietal-temporal and frontolateral groups revealed poorer overall performance with the former demonstrating problems with fluency related measures, whereas the latter were also less proficient at producing original responses. In contrast, the basal ganglia and frontopolar groups demonstrated superior performance in the ability to overcome the constraints imposed by salient semantic distractors when generating creative responses. In summary, the dissociations in the findings reveal the selective involvement of different brain regions in diverse aspects of creativity. Lesion location posed selective limitations on the ability to generate original responses in different contexts, but not on the ability to generate relevant responses, which was compromised in most patient groups. The noteworthy findings from this exploratory study of enhanced performance in specific aspects of creative cognition following brain damage are discussed with reference to the generic idea that superior creative ability can result from altered brain function. PMID:22982590

Abraham, Anna; Beudt, Susan; Ott, Derek V M; Yves von Cramon, D

2012-10-30

141

Deep Arteriovenous Malformations in the Basal Ganglia, Thalamus, and Insula: Microsurgical Management, Techniques, and Results  

PubMed Central

Background Arteriovenous malformations (AVMs) in the basal ganglia, thalamus, and insula are considered inoperable given their depth, eloquence, and limited surgical exposure. While many neurosurgeons opt for radiosurgery or observation, others have challenged the belief that deep AVMs are inoperable. Further discussion of patient selection, technique, and multimodality management is needed. Objective To describe and discuss the technical considerations of microsurgical resection for deep-seated AVMs. Methods Patients with deep AVMs who underwent surgery during a 14-year period were reviewed using a prospective AVM registry. Results Microsurgery was performed in 48 patients with AVMs in the basal ganglia (n=10), thalamus (n=13), or insula (n=25). The most common Spetzler-Martin grade was III- (68%). Surgical approaches included transsylvian (67%), transcallosal (19%), and transcortical (15%). Complete resection was achieved in 34 patients (71%), and patients with incomplete resection were treated with radiosurgery. Forty-five patients (94%) were improved or unchanged (mean follow-up 1.6 years). Conclusion This experience advances the notion that select deep AVMs may be operable lesions. Patients were highly selected for small size, hemorrhagic presentation, young age, and compactness factors embodied in the Spetzler-Martin and Supplementary grading systems. Overall, 10 different approaches were used, exploiting direct, transcortical corridors created by hemorrhage or maximizing anatomical corridors through subarachnoid spaces and ventricles that minimize brain transgression. The same cautious attitude exercised in selecting patients for surgery was also exercised in deciding extent of resection, opting for incomplete resection and radiosurgery more than with other AVMs to prioritize neurological outcomes. PMID:23728451

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

2014-01-01

142

Region of Interest Template for the Human Basal Ganglia: Comparing EPI and Standardized Space Approaches  

PubMed Central

Identifying task related activation in the basal ganglia (BG) is an important area of interest in normal motor systems and cognitive neuroscience. The purpose of this study was to compare changes in brain activation in the BG using results obtained from two different masking methods: a mask drawn in standardized space from a T1 weighted anatomical image and individual region of interest (ROI) masks drawn from each subjects echo-planar (EPI) image from different tasks with reference to the high resolution fast spin echo image of each subject. Two standardized masks were used: a mask developed in Talairach space (Basal Ganglia Human Area Template (BGHAT)) and a mask developed in Montreal Neurological Institute space (MNI mask). Ten subjects produced fingertip force pulses in five separate contraction tasks during fMRI scanning. ROIs were the left caudate, putamen, external and internal portions of the globus pallidus, and subthalamic nucleus. ANOVA revealed a similar average number of voxels in the EPI mask across tasks in each BG region. The percent signal change (PSC) was consistent within each region regardless of which mask was used. Linear regression analyses between PSC in BGHAT and EPI masks and MNI and EPI masks yielded r values between 0.740.99 and 0.700.99 across regions, respectively. In conclusion, PSC in different BG ROIs can be compared across studies using these different masking methods. The masking method used does not affect the overall interpretation of results with respect to the effect of task. Use of a mask drawn in standardized space is a valid and time saving method of identifying PSC in the small nuclei of the BG. PMID:17988895

Janey Prodoehl, PT; Yu, Hong; Little, Deborah M.; Abraham, Ivy; Vaillancourt, David E.

2008-01-01

143

Basal Ganglia Volume Is Associated with Aerobic Fitness in Preadolescent Children  

PubMed Central

The present investigation is the first to explore the association between childhood aerobic fitness and basal ganglia structure and function. Rodent research has revealed that exercise influences the striatum by increasing dopamine signaling and angiogenesis. In children, higher aerobic fitness levels are associated with greater hippocampal volumes, superior performance on tasks of attentional and interference control, and elevated event-related brain potential indices of executive function. The present study used magnetic resonance imaging to investigate if higher-fit and lower-fit 9- and 10-year-old children exhibited differential volumes of other subcortical brain regions, specifically the basal ganglia involved in attentional control. The relationship between aerobic fitness, dorsal and ventral striatum volumes and performance on an attention and inhibition Eriksen flanker task was also examined. The results indicated that higher-fit children showed superior flanker task performance compared to lower-fit children. Higher-fit children also showed greater volumes of the dorsal striatum, and dorsal striatum volume was negatively associated with behavioral interference. The results support the claim that the dorsal striatum is involved in cognitive control and response resolution and that these cognitive processes vary as a function of aerobic fitness. No relationship was found between aerobic fitness, the volume of the ventral striatum and flanker performance. The findings suggest that increased childhood aerobic fitness is associated with greater dorsal striatal volumes and that this is related to enhanced cognitive control. Because children are becoming increasingly overweight, unhealthy and unfit, understanding the neurocognitive benefits of an active lifestyle during childhood has important public health and educational implications. PMID:20693803

Chaddock, Laura; Erickson, Kirk I.; Prakash, Ruchika Shaurya; VanPatter, Matt; Voss, Michelle W.; Pontifex, Matthew B.; Raine, Lauren B.; Hillman, Charles H.; Kramer, Arthur F.

2010-01-01

144

Beta Frequency Synchronization in Basal Ganglia Output during Rest and Walk in a Hemiparkinsonian Rat  

PubMed Central

Synchronized oscillatory neuronal activity in the beta frequency range has been observed in the basal ganglia of Parkinsons disease patients and hypothesized to be antikinetic. The unilaterally lesioned rat model of Parkinsons disease allows examination of this hypothesis by direct comparison of beta activity in basal ganglia output in non-lesioned and dopamine cell lesioned hemispheres during motor activity. Bilateral substantia nigra pars reticulata (SNpr) recordings of units and local field potentials (LFP) were obtained with EMG activity from the scapularis muscle in control and unilaterally nigrostriatal lesioned rats trained to walk on a rotary treadmill. After left hemispheric lesion, rats had difficulty walking contraversive on the treadmill but could walk in the ipsiversive direction. During inattentive rest, SNpr LFP power in the 1225 Hz range (low beta) was significantly greater in the dopamine-depleted hemisphere than in non-lesioned and control hemispheres. During walking, low beta power was reduced in all hemispheres, while 2540 Hz (high beta) activity was selectively increased in the lesioned hemisphere. High beta power increases were reduced by L-DOPA administration. SNpr spiking was significantly more synchronized with SNpr low beta LFP oscillations during rest and high beta LFP oscillations during walking in the dopamine-depleted hemispheres compared with non-lesioned hemispheres. Data show that dopamine loss is associated with opposing changes in low and high beta range SNpr activity during rest and walk and suggest that increased synchronization of high beta activity in SNpr output from the lesioned hemisphere during walking may contribute to gait impairment in the hemiparkinsonian rat. PMID:19948166

Avila, Irene; Parr-Brownlie, Louise C.; Brazhnik, Elena; Castaneda, Edward; Bergstrom, Debra A.; Walters, J. R.

2012-01-01

145

High Uptake on 11C-methionine Positron Emission Tomographic Scan of Basal Ganglia Germinoma with Cerebral Hemiatrophy  

Microsoft Academic Search

Summary: We herein describe a 12-year-old male patient with a germinoma of the basal ganglia who presented with progressive hemiparesis. MR imaging showed ipsilateral cerebral hemiatrophy predominantly in the left basal gan- glia, whereas no mass or enhancement was depicted. Single photon emission CT revealed no significant uptake of thal- lium, whereas 11C-methionine positron emission tomogra- phy showed clearly discernible

Akira Sudo; Tohru Shiga; Maki Okajima; Kyoko Takano; Satoshi Terae; Yutaka Sawamura; Akiko Ohnishi; Kazuo Nagashima; Shinji Saitoh

146

Mechanism of parkinsonian neuronal oscillations in the primate basal ganglia: some considerations based on our recent work  

PubMed Central

Accumulating evidence suggests that abnormal neuronal oscillations in the basal ganglia (BG) contribute to the manifestation of parkinsonian symptoms. In this article, we would like to summarize our recent work on the mechanism underlying abnormal oscillations in the parkinsonian state and discuss its significance in pathophysiology of Parkinsons disease. We recorded neuronal activity in the BG of parkinsonian monkeys treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Systemic administration of L-DOPA alleviated parkinsonian motor signs and decreased abnormal neuronal oscillations (815 Hz) in the internal (GPi) and external (GPe) segments of the globus pallidus and the subthalamic nucleus (STN). Inactivation of the STN by muscimol (GABAA receptor agonist) injection also ameliorated parkinsonian signs and suppressed GPi oscillations. The blockade of glutamatergic inputs to the STN by local microinjection of a mixture of 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (glutamatergic NMDA receptor antagonist) and 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide (glutamatergic AMPA/kainate receptor antagonist) suppressed neuronal oscillations in the STN. STN oscillations were also attenuated by the blockade of GABAergic neurotransmission from the GPe to the STN by muscimol inactivation of the GPe. These results suggest that cortical glutamatergic inputs to the STN and reciprocal GPe-STN interconnections are both important for the generation and amplification of the oscillatory activity of GPe and STN neurons in the parkinsonian state. The oscillatory activity in the STN is subsequently transmitted to the GPi and may contribute to manifestation of parkinsonian symptoms. PMID:24904309

Nambu, Atsushi; Tachibana, Yoshihisa

2014-01-01

147

Using point process models to determine the impact of visual cues on basal ganglia activity and behavior of Parkinson's patients  

Microsoft Academic Search

Deep brain stimulation is an effective therapy for Parkinson's disease (PD) that has enabled microelectrode recordings from single-unit cells in the sub-thalamic nucleus (STN) of the basal ganglia. This rare data is important to develop detailed characterizations of spiking activity to understand the pathophysiology of PD. Despite the point process nature of neuronal spiking activity, point process (PP) methods are

Sridevi V. Sarma; Uri T. Eden; Ming L. Cheng; Ziv Williams; Emad N. Eskandar; Emery N. Brown

2009-01-01

148

Basal Ganglia, Dopamine and Temporal Processing: Performance on Three Timing Tasks on and off Medication in Parkinson's Disease  

ERIC Educational Resources Information Center

A pervasive hypothesis in the timing literature is that temporal processing in the milliseconds and seconds range engages the basal ganglia and is modulated by dopamine. This hypothesis was investigated by testing 12 patients with Parkinson's disease (PD), both "on" and "off" dopaminergic medication, and 20 healthy controls on three timing tasks.

Jones, Catherine R. G.; Malone, Tim J. L.; Dirnberger, Georg; Edwards, Mark; Jahanshahi, Marjan

2008-01-01

149

Presynaptic Depression of Glutamatergic Synaptic Transmission by D1Like Dopamine Receptor Activation in the Avian Basal Ganglia  

Microsoft Academic Search

Vocal behavior in songbirds exemplifies a rich integration of motor, cognitive, and social functions that are shared among vertebrates. As a part of the underlying neural substrate, the song system, the anterior forebrain pathway (AFP) is required for song learning and maintenance. The AFP resembles the mammalian basal ganglia-thalamocortical loop in its macroscopic organization, neuronal intrinsic properties, and microcircuitry. Area

Long Ding; David J. Perkel; Michael A. Farries

2003-01-01

150

Left and right basal ganglia and frontal activity during language generation: Contributions to lexical, semantic, and phonological processes  

Microsoft Academic Search

f MRI was used to determine the frontal, basal ganglia, and thalamic structures engaged by three facets of language generation: lexical status of generated items, the use of semantic vs. phonological information during language generation, and rate of generation. During f MRI, 21 neurologically normal subjects performed four tasks: generation of nonsense syllables given beginning and ending consonant blends, generation

BRUCE CROSSON; HOPE BENEFIELD; M. ALLISON CATO; JOSEPH R. SADEK; ANNA BACON MOORE; CHRISTINA E. WIERENGA; KAUNDINYA GOPINATH; DAVID SOLTYSIK; RUSSELL M. BAUER; EDWARD J. AUERBACH; DIDEM GKAY; CHRISTIANA M. LEONARD; RICHARD W. BRIGGS

2003-01-01

151

Basal Ganglia Structures Differentially Contribute to Verbal Fluency: Evidence from Human Immunodeficiency Virus (HIV)-Infected Adults  

ERIC Educational Resources Information Center

Background: The basal ganglia (BG) are involved in executive language functions (i.e., verbal fluency) through their connections with cortical structures. The caudate and putamen receive separate inputs from prefrontal and premotor cortices, and may differentially contribute to verbal fluency performance. We examined BG integrity in relation to

Thames, April D.; Foley, Jessica M.; Wright, Matthew J.; Panos, Stella E.; Ettenhofer, Mark; Ramezani, Amir; Streiff, Vanessa; El-Saden, Suzie; Goodwin, Scott; Bookheimer, Susan Y.; Hinkin, Charles H.

2012-01-01

152

Impaired Frontal-Basal Ganglia Connectivity in Adolescents with Internet Addiction  

PubMed Central

Understanding the neural basis of poor impulse control in Internet addiction (IA) is important for understanding the neurobiological mechanisms of this syndrome. The current study investigated how neuronal pathways implicated in response inhibition were affected in IA using a Go-Stop paradigm and functional magnetic resonance imaging (fMRI). Twenty-three control subjects aged 15.2 0.5 years (mean S.D.) and eighteen IA subjects aged 15.1 1.4 years were studied. Effective connectivity within the response inhibition network was quantified using (stochastic) dynamic causal modeling (DCM). The results showed that the indirect frontal-basal ganglia pathway was engaged by response inhibition in healthy subjects. However, we did not detect any equivalent effective connectivity in the IA group. This suggests the IA subjects fail to recruit this pathway and inhibit unwanted actions. This study provides a clear link between Internet addiction as a behavioral disorder and aberrant connectivity in the response inhibition network. PMID:24848380

Li, Baojuan; Friston, Karl J.; Liu, Jian; Liu, Yang; Zhang, Guopeng; Cao, Fenglin; Su, Linyan; Yao, Shuqiao; Lu, Hongbing; Hu, Dewen

2014-01-01

153

Radiation absorbed dose to the basal ganglia from dopamine transporter radioligand 18F-FPCIT.  

PubMed

Our previous dosimetry studies have demonstrated that for dopaminergic radiotracers, (18)F-FDOPA and (18)F-FPCIT, the urinary bladder is the critical organ. As these tracers accumulate in the basal ganglia (BG) with high affinity and long residence times, radiation dose to the BG may become significant, especially in normal control subjects. We have performed dynamic PET measurements using (18)F-FPCIT in 16 normal adult subjects to determine if in fact the BG, although not a whole organ, but a well-defined substructure, receives the highest dose. Regions of interest were drawn over left and right BG structures. Resultant time-activity curves were generated and used to determine residence times for dosimetry calculations. S-factors were computed using the MIRDOSE3 nodule model for each caudate and putamen. For (18)F-FPCIT, BG dose ranged from 0.029 to 0.069 mGy/MBq. In half of all subjects, BG dose exceeded 85% of the published critical organ (bladder) dose, and in three of those, the BG dose exceeded that for the bladder. The BG can become the dose-limiting organ in studies using dopamine transporter ligands. For some normal subjects studied with F-18 or long half-life radionuclide, the BG may exceed bladder dose and become the critical structure. PMID:25093172

Robeson, William; Dhawan, Vijay; Ma, Yilong; Bjelke, David; Margouleff, Claude; Chaly, Thomas; Eidelberg, David

2014-01-01

154

[Gamma knife treatment of AVM of the basal ganglia and thalamus].  

PubMed

Arteriovenous malformatios (AVMs) in the basal ganglia (BG) and thalamus (Thal) are difficult to treat by microsurgery or intravascular embolization alone, and the role of stereotactic gamma radiosurgery (gamma knife) of these AVMs is discussed. We have treated 324 cases of AVM with gamma knife since May 1991, and in 71 of these cases (19%) the AVM was in the BG or Thal. The results of gamma radiosurgery on AVMs of the BG and Thal were compared with the results of treating AVMs at other intracranial locations by gamma radiosurgery. The nidi were small (mean diameter: 16.4 mm), and they were treated with a mean maximum dose of 36.4 Gy and marginal dose of 19.9 Gy. The results were evaluated angiographically in 39 (55%) of the 71 cases, with a mean follow-up period of 23 months. The complete obliteration rate of AVMs in the BG and Thal 1 and 2 years after treatment was 54.3% and 92.0%, respectively, and the rate at the other locations was 42.9% and 76.0%, respectively. Adverse effects of this treatment in the AVM cases overall were rebleeding from the nidus in 5 cases (1.5%) and radiation necrosis in 4 cases (1.2%). In conclusion, AVMs of the BG and Thal were effectively and safely treated with the gamma knife, and stereotactic radiosurgery is a definitive alternative treatment for deep seated AVMs. PMID:8679332

Kobayashi, T; Tanaka, T; Kida, Y; Oyama, H; Niwa, M; Maesawa, S

1996-04-01

155

Multiplicity of control in the basal ganglia: computational roles of striatal subregions.  

PubMed

The basal ganglia, in particular the striatum, are central to theories of behavioral control, and often identified as a seat of action selection. Reinforcement learning (RL) models--which have driven much recent experimental work on this region--cast striatum as a dynamic controller, integrating sensory and motivational information to construct efficient and enriching behavioral policies. Befitting this informationally central role, the BG sit at the nexus of multiple anatomical 'loops' of synaptic projections, connecting a wide range of cortical and subcortical structures. Numerous pioneering anatomical studies conducted over the past several decades have meticulously catalogued these loops, and labeled them according to the inferred functions of the connected regions. The specific cotermina of the projections are highly localized to several different subregions of the striatum, leading to the suggestion that these subregions perform complementary but distinct functions. However, until recently, the dominant computational framework outlined only a bipartite, dorsal/ventral, division of striatum. We review recent computational and experimental advances that argue for a more finely fractionated delineation. In particular, experimental data provide extensive insight into unique functions subserved by the dorsomedial striatum (DMS). These functions appear to correspond well with theories of a 'model-based' RL subunit, and may also shed light on the suborganization of ventral striatum. Finally, we discuss the limitations of these ideas and how they point the way toward future refinements of neurocomputational theories of striatal function, bringing them into contact with other areas of computational theory and other regions of the brain. PMID:21429734

Bornstein, Aaron M; Daw, Nathaniel D

2011-06-01

156

Neurocomputational models of basal ganglia function in learning, memory and choice  

PubMed Central

The basal ganglia (BG) are critical for the coordination of several motor, cognitive, and emotional functions and become dysfunctional in several pathological states ranging from Parkinson's disease to Schizophrenia. Here we review principles developed within a neurocomputational framework of BG and related circuitry which provide insights into their functional roles in behavior. We focus on two classes of models: those that incorporate aspects of biological realism and constrained by functional principles, and more abstract mathematical models focusing on the higher level computational goals of the BG. While the former are arguably more realistic, the latter have a complementary advantage in being able to describe functional principles of how the system works in a relatively simple set of equations, but are less suited to making specific hypotheses about the roles of specific nuclei and neurophysiological processes. We review the basic architecture and assumptions of these models, their relevance to our understanding of the neurobiological and cognitive functions of the BG, and provide an update on the potential roles of biological details not explicitly incorporated in existing models. Empirical studies ranging from those in transgenic mice to dopaminergic manipulation, deep brain stimulation, and genetics in humans largely support model predictions and provide the basis for further refinement. Finally, we discuss possible future directions and possible ways to integrate different types of models. PMID:18950662

Cohen, Michael X; Frank, Michael J.

2009-01-01

157

Manganese Exposure is Cytotoxic and Alters Dopaminergic and GABAergic Neurons within the Basal Ganglia  

PubMed Central

Manganese is an essential nutrient, integral to proper metabolism of amino acids, proteins and lipids. Excessive environmental exposure to manganese can produce extrapyramidal symptoms similar to those observed in Parkinsons disease (PD). We used in vivo and in vitro models to examine cellular and circuitry alterations induced by manganese exposure. Primary mesencephalic cultures were treated with 1000M manganese chloride (MnCl2) which resulted in dramatic changes in the neuronal cytoskeleton even at subtoxic concentrations. Using cultures from mice with red fluorescent protein (RFP) driven by the tyrosine hydroxylase (TH) promoter, we found that dopaminergic neurons were more susceptible to manganese toxicity. To understand the vulnerability of dopaminergic cells to chronic manganese exposure, mice were given IP injections of MnCl2 for 30 days. We observed a 20% reduction in TH-positive neurons in the substantia nigra pars compacta (SNpc) following manganese treatment. Quantification of Nissl bodies revealed a widespread reduction in SNpc cell numbers. Other areas of the basal ganglia were also altered by manganese as evidenced by the loss of GAD67 in the striatum. These studies suggest that acute manganese exposure induces cytoskeletal dysfunction prior to degeneration and that chronic manganese exposure results in neurochemical dysfunction with overlapping features to PD. PMID:19457100

Stanwood, Gregg D.; Leitch, Duncan B.; Savchenko, Valentina; Wu, Jane; Fitsanakis, Vanessa A.; Anderson, Douglas J.; Stankowski, Jeannette N.; Aschner, Michael; McLaughlin, BethAnn

2009-01-01

158

A hypothesis for basal ganglia-dependent reinforcement learning in the songbird  

PubMed Central

Most of our motor skills are not innately programmed, but are learned by a combination of motor exploration and performance evaluation, suggesting that they proceed through a reinforcement learning (RL) mechanism. Songbirds have emerged as a model system to study how a complex behavioral sequence can be learned through an RL-like strategy. Interestingly, like motor sequence learning in mammals, song learning in birds requires a basal ganglia (BG)-thalamocortical loop, suggesting common neural mechanisms. Here we outline a specific working hypothesis for how BG-forebrain circuits could utilize an internally computed reinforcement signal to direct song learning. Our model includes a number of general concepts borrowed from the mammalian BG literature, including a dopaminergic reward prediction error and dopamine mediated plasticity at corticostriatal synapses. We also invoke a number of conceptual advances arising from recent observations in the songbird. Specifically, there is evidence for a specialized cortical circuit that adds trial-to-trial variability to stereotyped cortical motor programs, and a role for the BG in biasing this variability to improve behavioral performance. This BG-dependent premotor bias may in turn guide plasticity in downstream cortical synapses to consolidate recently-learned song changes. Given the similarity between mammalian and songbird BG-thalamocortical circuits, our model for the role of the BG in this process may have broader relevance to mammalian BG function. PMID:22015923

Fee, Michale S.; Goldberg, Jesse H.

2011-01-01

159

Indirect basal ganglia pathway mediation of repetitive behavior: attenuation by adenosine receptor agonists.  

PubMed

Repetitive behaviors are diagnostic for autism and common in related neurodevelopmental disorders. Despite their clinical importance, underlying mechanisms associated with the expression of these behaviors remain poorly understood. Our lab has previously shown that the rates of spontaneous stereotypy in deer mice (Peromyscus maniculatus) were negatively correlated with enkephalin content, a marker of striatopallidal but not striatonigral neurons. To investigate further the role of the indirect basal ganglia pathway, we examined neuronal activation of the subthalamic nucleus (STN) using cytochrome oxidase (CO) histochemistry in high- and low-stereotypy mice. CO activity in STN was significantly lower in high-stereotypy mice and negatively correlated with the frequency of stereotypy. In addition, exposure to environmental enrichment, which attenuated stereotypy, normalized the activity of STN. Co-administration of the adenosine A(2A) receptor agonist CGS21680 and the A(1) receptor agonist CPA attenuated stereotypy dose-dependently. The significant reduction associated with the lowest dose of the drug combination tested was due to its effects on mice with lower baseline levels of stereotypy. Higher doses of the drug combination were required to show robust behavioral effects, and presumably requisite activation of the indirect pathway, in high-stereotypy mice. These findings support that decreased indirect pathway activity is linked to the expression of high levels of stereotypy in deer mice and that striatal A(1) and A(2A) receptors may provide promising therapeutic targets for the treatment of repetitive behaviors in neurodevelopmental disorders. PMID:20178817

Tanimura, Yoko; Vaziri, Sasha; Lewis, Mark H

2010-06-26

160

A de novo nonsense PDGFB mutation causing idiopathic basal ganglia calcification with laryngeal dystonia.  

PubMed

Idiopathic basal ganglia calcification (IBGC) is characterized by brain calcification and a wide variety of neurologic and psychiatric symptoms. In families with autosomal dominant inheritance, three causative genes have been identified: SLC20A2, PDGFRB, and, very recently, PDGFB. Whereas in clinical practice sporadic presentation of IBGC is frequent, well-documented reports of true sporadic occurrence are rare. We report the case of a 20-year-old woman who presented laryngeal dystonia revealing IBGC. Her healthy parents' CT scans were both normal. We identified in the proband a new nonsense mutation in exon 4 of PDGFB, c.439C>T (p.Gln147*), which was absent from the parents' DNA. This mutation may result in a loss-of-function of PDGF-B, which has been shown to cause IBGC in humans and to disrupt the blood-brain barrier in mice, resulting in brain calcification. The c.439C>T mutation is located between two previously reported nonsense mutations, c.433C>T (p.Gln145*) and c.445C>T (p.Arg149*), on a region that could be a hot spot for de novo mutations. We present the first full demonstration of the de novo occurrence of an IBGC-causative mutation in a sporadic case. PMID:24518837

Nicolas, Gal; Jacquin, Agns; Thauvin-Robinet, Christel; Rovelet-Lecrux, Anne; Rouaud, Olivier; Pottier, Cyril; Aubriot-Lorton, Marie-Hlne; Rousseau, Stphane; Wallon, David; Duvillard, Christian; Bjot, Yannick; Frbourg, Thierry; Giroud, Maurice; Campion, Dominique; Hannequin, Didier

2014-10-01

161

Evaluation of basal ganglia, brainstem raphe and ventricles in bipolar disorder by transcranial sonography.  

PubMed

Transcranial brain sonography (TCS) has become a reliable and sensitive diagnostic tool in the evaluation of extrapyramidal movement disorders. Alterations of brainstem raphe (BR) have been depicted by TCS in major depression but not in bipolar disorder. The aim of our study was to evaluate BR echogenicity depending on the different conditions of bipolar patients. Echogenicities of dopaminergic basal ganglia structures were assessed for the first time in bipolar disorder. Thirty-six patients with bipolar I disorder (14 depressed, 8 manic, 14 euthymic) were compared to 35 healthy controls. Echogenicities were investigated according to the examination protocol for extrapyramidal disorders using a Siemens Sonoline Elegra system. The sonography examiner was blinded for clinical rating scores. Six patients (16.7%) showed hyperechogenicity of the substantia nigra. The raphe was hypoechogenic in 13 (36.1%) of the patients. No significant differences were seen between the subgroups. Compared to the control group, frequency of altered echogenicities did not reach statistical significance. The width of third ventricle was significantly larger in the patient group (3.8-2.1 mm vs. 2.71.2 mm). Depressed bipolar patients with reduced BR echogenicity showed significantly higher scores on the Hamilton Depression Rating Scale as well as the Montgomery-sberg Depression Rating Scale. In contrast to unipolar depression, sonographic findings of bipolar patients may generally indicate structural integrity of mesencephalic raphe structures. If bipolar disorder coexists with hypoechogenic raphe structure, depressive symptoms are more severe. PMID:21958513

Krogias, Christos; Hoffmann, Kija; Eyding, Jens; Scheele, Dirk; Norra, Christine; Gold, Ralf; Juckel, Georg; Assion, Hans-Jrg

2011-11-30

162

A decrease in the size of the basal ganglia following prenatal alcohol exposure: a preliminary report.  

PubMed

Prenatal alcohol exposure is known to cause damage to the central nervous system. This study sought to further elucidate the structural brain damage that occurs following prenatal alcohol exposure in both children and rats. Two children with histories of maternal alcohol abuse but who did not qualify for a diagnosis of Fetal Alcohol Syndrome (FAS), based on established criteria, underwent magnetic resonance imaging. Reduced volumes were found for the cerebrum and cerebellum. In addition, the proportional volume of the basal ganglia was reduced, although the proportional volumes of cortical and subcortical fluid, cortical gray matter, limbic and nonlimbic cortex, and diencephalic structures were unaffected. These findings are compared with our recent MRI findings in two cases of FAS. In addition, the caudate-putamen and ventricular areas were assessed in rats exposed to alcohol prenatally. Whereas the overall brain section area was not reduced in size, the area of the caudate-putamen was reduced and that of the ventricles was enlarged. PMID:7935262

Mattson, S N; Riley, E P; Jernigan, T L; Garcia, A; Kaneko, W M; Ehlers, C L; Jones, K L

1994-01-01

163

Technical Integration of Hippocampus, Basal Ganglia and Physical Models for Spatial Navigation  

PubMed Central

Computational neuroscience is increasingly moving beyond modeling individual neurons or neural systems to consider the integration of multiple models, often constructed by different research groups. We report on our preliminary technical integration of recent hippocampal formation, basal ganglia and physical environment models, together with visualisation tools, as a case study in the use of Python across the modelling tool-chain. We do not present new modeling results here. The architecture incorporates leaky-integrator and rate-coded neurons, a 3D environment with collision detection and tactile sensors, 3D graphics and 2D plots. We found Python to be a flexible platform, offering a significant reduction in development time, without a corresponding significant increase in execution time. We illustrate this by implementing a part of the model in various alternative languages and coding styles, and comparing their execution times. For very large-scale system integration, communication with other languages and parallel execution may be required, which we demonstrate using the BRAHMS framework's Python bindings. PMID:19333376

Fox, Charles; Humphries, Mark; Mitchinson, Ben; Kiss, Tamas; Somogyvari, Zoltan; Prescott, Tony

2008-01-01

164

Receptorreceptor interactions as studied with microdialysis. Focus on NTR\\/D 2 interactions in the basal ganglia  

Microsoft Academic Search

Summary.Using mono and dualprobe(s) microdialysis in the basal ganglia of the freely moving rat evidence has been obtained that neurotensin\\u000a (NT) in threshold concentrations can counteract the D2 agonist (intrastriatally perfused) induced inhibition of striatal dopamine (DA) release and of pallidal GABA release from\\u000a the striato-pallidal GABA pathway, effects that are blocked by a NTR1 antagonist SR48692. These results indicate

T. Antonelli; M. C. Tomasini; K. Fuxe; L. F. Agnati; S. Tanganelli; L. Ferraro

2007-01-01

165

Physiological evidence for a trans-basal ganglia pathway linking extrastriate visual cortex and the superior colliculus  

PubMed Central

Abstract Visually responsive regions along the cat's lateral suprasylvian (LS) sulcus provide excitatory inputs to the deep layers of the superior colliculus (SC). It is via this direct cortico-collicular route that LS cortex is thought to enhance the visual activity of SC output neurons and thereby facilitate SC-mediated orientation behaviours. However, it has long been suggested that LS also might influence the SC via an indirect route through the basal ganglia. Such a multi-synaptic route would ultimately modulate SC activity via basal ganglia output neurons in substantia nigra, pars reticulata. Using cortical electrical stimulation, the present experiments in the anaesthetized cat provide a physiological confirmation of this indirect route. Moreover, the patterns of activity evoked in antidromically identified nigro-collicular neurons indicate the involvement of multiple trans-basal ganglia pathways. The most complex evoked patterns consisted of a variable period of inhibition preceded and followed by periods of excitation. Although many neurons displayed only components of this triphasic response, these electrically evoked responses generally matched the characteristics of their responses to natural visual stimuli. Cortical stimulation evoked excitation in all of crossed nigro-collicular neurons and inhibition in the majority of uncrossed nigro-collicular neurons. These data suggest that LS activity accesses multiple trans-basal ganglia circuits that shape nigro-collicular responses that are appropriate for their SC targets. In this way, visual stimuli in one hemifield can be selected as targets for SC-mediated orientation, while simultaneously inhibiting activity in the opposite SC that might generate responses to competing targets. PMID:21986209

Jiang, Huai; Stein, Barry E; McHaffie, John G

2011-01-01

166

Age-related changes of the functional architecture of the cortico-basal ganglia circuitry during motor task execution  

Microsoft Academic Search

Normal human aging is associated with declining motor control and function. It is thought that dysfunction of the cortico-basal ganglia circuitry may contribute to age-related sensorimotor impairment, however the underlying mechanisms are poorly characterized. The aim of this study was to enhance our understanding of age-related changes in the functional architecture of these circuits. Fifty-nine subjects, consisting of a young,

William R. Marchand; James N. Lee; Yana Suchy; Cheryl Garn; Susanna Johnson; Nicole Wood; Gordon Chelune

2011-01-01

167

Microsurgical treatment assisted by intraoperative ultrasound localization: a controlled trial in patients with hypertensive basal ganglia hemorrhage.  

PubMed

This study investigated the clinical value of performing microsurgical treatment on hypertensive basal ganglia hemorrhage assisted by intraoperative ultrasound localization (IUL). A total of 107 patients with hypertensive basal ganglia hemorrhage were randomly separated into two groups for this controlled clinical trial. In the IUL group, 51 patients with hypertensive basal ganglia hemorrhage were operated on with the support of ultrasonic imaging; 56 patients underwent conventional microsurgery to evacuate the hemorrhage. The results of the two methods were evaluated according to the rate of hematoma evacuation, re-hemorrhage, mortality, complications, and activities of daily living (ADL). A greater quantity of the hemorrhage was removed from patients in the IUL group, with over 90% of masses being eliminated from the brain in 78.43% of these patients (40 out of 51 patients) compared with 60.71% of patients in the control group (34 out of 56 patients). The IUL group experienced a lower rate of re-hemorrhage after the operation (7.84%, 4 out of 51 patients) compared with the control group (17.86%, 10 out of 56 patients). A significant difference in the ADL score was recorded between the two groups, with ADL scores of the IUL group exceeding 60 (indicating good recovery) at 6 months after the operative procedure (P < 0.05). In conclusion, the microsurgical treatment of hypertensive basal ganglia hemorrhage assisted by IUL improved the precision of the operation. This procedure removed the hemorrhage and reduced the changes of re-occurrence, as well as elevated the quality of life of patients after the operation. PMID:24350736

Miao, Zeng Li; Jiang, Li; Xu, Xing; Chen, Kai Lai; Lu, Xiao Jie

2014-08-01

168

[Idiopathic bilateral basal ganglia calcification (Fahr's disease) presenting with psychotic depression and criminal violence: a case report with forensic aspect].  

PubMed

Fahr's disease is a rare neuropsychiatric disease characterized by bilateral intracranial calcification, primarily in the basal ganglia. The more general term, Fahr's syndrome, is used for primary and secondary basal ganglia calcification, regardless of the etiology, but the term Fahr's disease is used to describe primary, idiopathic cases. Fahr's disease may present with neurological symptoms, such as parkinsonism and extrapyramidal symptoms, dysarthria, paresis, convulsion, and syncope. Psychiatric disorders, including behavioral disorders, psychosis, and mood disorders, as well as cognitive disorders can occur. CT is useful for the diagnosis of Fahr's disease. Herein we present a patient diagnosed as Fahr's disease that presented with symptoms of depression, delusions, and auditory hallucinations. The 47-year-old male patient was hospitalized in a forensic psychiatry inpatient clinic due to aggressive behavior and was subsequently diagnosed with major depressive disorder with psychotic features. While hospitalized he was treated with antidepressant and antipsychotic drugs, as well as electroconvulsive therapy, resulting in significant improvement in his symptoms. As bilateral basal ganglia calcification was observed via CT, the patient was diagnosed as Fahr's disease. This case report emphasizes the importance of cranial imaging and detailed laboratory examination when evaluating patients with psychosis and affective symptoms. Pathologies such as Fahr's disease must be included in the differential diagnosis, especially in cases with neurological symptoms and cranial imaging findings. PMID:24936761

zer, rn; Grgl, Yasemin; Can Gngr, Ferda; Gentrk, Mert

2014-01-01

169

Conditional Routing of Information to the Cortex: A Model of the Basal Ganglia's Role in Cognitive Coordination  

PubMed Central

The basal ganglia play a central role in cognition and are involved in such general functions as action selection and reinforcement learning. Here, we present a model exploring the hypothesis that the basal ganglia implement a conditional information-routing system. The system directs the transmission of cortical signals between pairs of regions by manipulating separately the selection of sources and destinations of information transfers. We suggest that such a mechanism provides an account for several cognitive functions of the basal ganglia. The model also incorporates a possible mechanism by which subsequent transfers of information control the release of dopamine. This signal is used to produce novel stimulusresponse associations by internalizing transferred cortical representations in the striatum. We discuss how the model is related to production systems and cognitive architectures. A series of simulations is presented to illustrate how the model can perform simple stimulusresponse tasks, develop automatic behaviors, and provide an account of impairments in Parkinsons and Huntingtons diseases. PMID:20438237

Stocco, Andrea; Lebiere, Christian; Anderson, John R.

2010-01-01

170

[Potential mechanisms of effects of endogenous neuromodulators on the interdependent activity of neurons in various nuclei of the basal ganglia].  

PubMed

A possible mechanism of influence of neuromodulators on interdependent activity of neurons in the diverse basal ganglia nuclei is suggested. According to modulation rules, an activation of postsynaptic Gs- or Gq/11-(Gi/0-) protein coupled receptors promotes induction of long-term potentiation (depression) of excitatory inputs to different neurons and augmentation (lowering) of their activity; an activation of presynaptic Gs- or Gq/11-(Gi/0-) protein coupled receptors promotes a rise (decrease) of release of GABA and co-peptides from striatal terminals and glutamate release from subthalamic terminals in the globus pallidus and output nuclei. It follows from the modulation rules that, since identical receptors are present on striatal neuron and their axon terminals, effects of neuromodulator action in diverse basal ganglia nuclei can be summarized. Neuromodulators released from striato-nigral and striato-pallidal fibers could promote interdependent activity of neurons in "direct" and "indirect" pathways through the basal ganglia due to convergence of these fibers on cholinergic interneurons and pallido-striatal cells. PMID:15152564

Sil'kis, I G

2004-03-01

171

A pilot study of basal ganglia and thalamus structure by high dimensional mapping in children with Tourette syndrome  

PubMed Central

Background: Prior brain imaging and autopsy studies have suggested that structural abnormalities of the basal ganglia (BG) nuclei may be present in Tourette Syndrome (TS). These studies have focused mainly on the volume differences of the BG structures and not their anatomical shapes. Shape differences of various brain structures have been demonstrated in other neuropsychiatric disorders using large-deformation, high dimensional brain mapping (HDBM-LD). A previous study of a small sample of adult TS patients demonstrated the validity of the method, but did not find significant differences compared to controls. Since TS usually begins in childhood and adult studies may show structure differences due to adaptations, we hypothesized that differences in BG and thalamus structure geometry and volume due to etiological changes in TS might be better characterized in children. Objective: Pilot the HDBM-LD method in children and estimate effect sizes. Methods: In this pilot study, T1-weighted MRIs were collected in 13 children with TS and 16 healthy, tic-free, control children. The groups were well matched for age. The primary outcome measures were the first 10 eigenvectors which are derived using HDBM-LD methods and represent the majority of the geometric shape of each structure, and the volumes of each structure adjusted for whole brain volume. We also compared hemispheric right/left asymmetry and estimated effect sizes for both volume and shape differences between groups. Results: We found no statistically significant differences between the TS subjects and controls in volume, shape, or right/left asymmetry. Effect sizes were greater for shape analysis than for volume. Conclusion: This study represents one of the first efforts to study the shape as opposed to the volume of the BG in TS, but power was limited by sample size. Shape analysis by the HDBM-LD method may prove more sensitive to group differences. PMID:24715957

Black, Kevin J.

2013-01-01

172

Motor thalamus integration of cortical, cerebellar and basal ganglia information: implications for normal and parkinsonian conditions  

PubMed Central

Motor thalamus (Mthal) is implicated in the control of movement because it is strategically located between motor areas of the cerebral cortex and motor-related subcortical structures, such as the cerebellum and basal ganglia (BG). The role of BG and cerebellum in motor control has been extensively studied but how Mthal processes inputs from these two networks is unclear. Specifically, there is considerable debate about the role of BG inputs on Mthal activity. This review summarizes anatomical and physiological knowledge of the Mthal and its afferents and reviews current theories of Mthal function by discussing the impact of cortical, BG and cerebellar inputs on Mthal activity. One view is that Mthal activity in BG and cerebellar-receiving territories is primarily driven by glutamatergic inputs from the cortex or cerebellum, respectively, whereas BG inputs are modulatory and do not strongly determine Mthal activity. This theory is steeped in the assumption that the Mthal processes information in the same way as sensory thalamus, through interactions of modulatory inputs with a single driver input. Another view, from BG models, is that BG exert primary control on the BG-receiving Mthal so it effectively relays information from BG to cortex. We propose a new super-integrator theory where each Mthal territory processes multiple driver or driver-like inputs (cortex and BG, cortex and cerebellum), which are the result of considerable integrative processing. Thus, BG and cerebellar Mthal territories assimilate motivational and proprioceptive motor information previously integrated in cortico-BG and cortico-cerebellar networks, respectively, to develop sophisticated motor signals that are transmitted in parallel pathways to cortical areas for optimal generation of motor programmes. Finally, we briefly review the pathophysiological changes that occur in the BG in parkinsonism and generate testable hypotheses about how these may affect processing of inputs in the Mthal. PMID:24273509

Bosch-Bouju, Clementine; Hyland, Brian I.; Parr-Brownlie, Louise C.

2013-01-01

173

Integration of cortical and pallidal inputs in the basal ganglia-recipient thalamus of singing birds  

PubMed Central

The basal ganglia-recipient thalamus receives inhibitory inputs from the pallidum and excitatory inputs from cortex, but it is unclear how these inputs interact during behavior. We recorded simultaneously from thalamic neurons and their putative synaptically connected pallidal inputs in singing zebra finches. We find, first, that each pallidal spike produces an extremely brief (?5 ms) pulse of inhibition that completely suppresses thalamic spiking. As a result, thalamic spikes are entrained to pallidal spikes with submillisecond precision. Second, we find that the number of thalamic spikes that discharge within a single pallidal interspike interval (ISI) depends linearly on the duration of that interval but does not depend on pallidal activity prior to the interval. In a detailed biophysical model, our results were not easily explained by the postinhibitory rebound mechanism previously observed in anesthetized birds and in brain slices, nor could most of our data be characterized as gating of excitatory transmission by inhibitory pallidal input. Instead, we propose a novel entrainment mechanism of pallidothalamic transmission that highlights the importance of an excitatory conductance that drives spiking, interacting with brief pulses of pallidal inhibition. Building on our recent finding that cortical inputs can drive syllable-locked rate modulations in thalamic neurons during singing, we report here that excitatory inputs affect thalamic spiking in two ways: by shortening the latency of a thalamic spike after a pallidal spike and by increasing thalamic firing rates within individual pallidal ISIs. We present a unifying biophysical model that can reproduce all known modes of pallidothalamic transmissionrebound, gating, and entrainmentdepending on the amount of excitation the thalamic neuron receives. PMID:22673333

Goldberg, Jesse H.; Farries, Michael A.

2012-01-01

174

Developmental Changes in the Organization of Functional Connections between the Basal Ganglia and Cerebral Cortex  

PubMed Central

The basal ganglia (BG) comprise a set of subcortical nuclei with sensorimotor, cognitive, and limbic subdivisions, indicative of functional organization. BG dysfunction in several developmental disorders suggests the importance of the healthy maturation of these structures. However, few studies have investigated the development of BG functional organization. Using resting-state functional connectivity MRI (rs-fcMRI), we compared human child and adult functional connectivity of the BG with rs-fcMRI-defined cortical systems. Because children move more than adults, customized preprocessing, including volume censoring, was used to minimize motion-induced rs-fcMRI artifact. Our results demonstrated functional organization in the adult BG consistent with subdivisions previously identified in anatomical tracing studies. Group comparisons revealed a developmental shift in bilateral posterior putamen/pallidum clusters from preferential connectivity with the somatomotor face system in childhood to preferential connectivity with control/attention systems (frontoparietal, ventral attention) in adulthood. This shift was due to a decline in the functional connectivity of these clusters with the somatomotor face system over development, and no change with control/attention systems. Applying multivariate pattern analysis, we were able to reliably classify individuals as children or adults based on BGcortical system functional connectivity. Interrogation of the features driving this classification revealed, in addition to the somatomotor face system, contributions by the orbitofrontal, auditory, and somatomotor hand systems. These results demonstrate that BGcortical functional connectivity evolves over development, and may lend insight into developmental disorders that involve BG dysfunction, particularly those involving motor systems (e.g., Tourette syndrome). PMID:24760844

Laumann, Timothy O.; Dubis, Joseph W.; Ihnen, S. Katie; Neta, Maital; Power, Jonathan D.; Pruett, John R.; Black, Kevin J.; Schlaggar, Bradley L.

2014-01-01

175

Developmental changes in the organization of functional connections between the basal ganglia and cerebral cortex.  

PubMed

The basal ganglia (BG) comprise a set of subcortical nuclei with sensorimotor, cognitive, and limbic subdivisions, indicative of functional organization. BG dysfunction in several developmental disorders suggests the importance of the healthy maturation of these structures. However, few studies have investigated the development of BG functional organization. Using resting-state functional connectivity MRI (rs-fcMRI), we compared human child and adult functional connectivity of the BG with rs-fcMRI-defined cortical systems. Because children move more than adults, customized preprocessing, including volume censoring, was used to minimize motion-induced rs-fcMRI artifact. Our results demonstrated functional organization in the adult BG consistent with subdivisions previously identified in anatomical tracing studies. Group comparisons revealed a developmental shift in bilateral posterior putamen/pallidum clusters from preferential connectivity with the somatomotor "face" system in childhood to preferential connectivity with control/attention systems (frontoparietal, ventral attention) in adulthood. This shift was due to a decline in the functional connectivity of these clusters with the somatomotor face system over development, and no change with control/attention systems. Applying multivariate pattern analysis, we were able to reliably classify individuals as children or adults based on BG-cortical system functional connectivity. Interrogation of the features driving this classification revealed, in addition to the somatomotor face system, contributions by the orbitofrontal, auditory, and somatomotor hand systems. These results demonstrate that BG-cortical functional connectivity evolves over development, and may lend insight into developmental disorders that involve BG dysfunction, particularly those involving motor systems (e.g., Tourette syndrome). PMID:24760844

Greene, Deanna J; Laumann, Timothy O; Dubis, Joseph W; Ihnen, S Katie; Neta, Maital; Power, Jonathan D; Pruett, John R; Black, Kevin J; Schlaggar, Bradley L

2014-04-23

176

Rule-Based Categorization Deficits in Focal Basal Ganglia Lesion and Parkinson's Disease Patients  

PubMed Central

Patients with basal ganglia (BG) pathology are consistently found to be impaired on rule-based category learning tasks in which learning is thought to depend upon the use of an explicit, hypothesis-guided strategy. The factors that influence this impairment remain unclear. Moreover, it remains unknown if the impairments observed in patients with degenerative disorders such as Parkinson's disease (PD) are also observed in those with focal BG lesions. In the present study, we tested patients with either focal BG lesions or PD on two categorization tasks that varied in terms of their demands on selective attention and working memory. Individuals with focal BG lesions were impaired on the task in which working-memory demand was high and performed similarly to healthy controls on the task in which selective-attention demand was high. In contrast, individuals with PD were impaired on both tasks, and accuracy rates did not differ between on- and off-medication states for a subset of patients who were also tested after abstaining from dopaminergic medication. Quantitative, model-based analyses attributed the performance deficit for both groups in the task with high working-memory demand to the utilization of suboptimal strategies, whereas the PD-specific impairment on the task with high selective-attention demand was driven by the inconsistent use of an optimal strategy. These data suggest that the demands on selective attention and working memory affect the presence of impairment in patients with focal BG lesions and the nature of the impairment in patients with PD. PMID:20600196

Ell, Shawn W.; Weinstein, Andrea; Ivry, Richard B.

2010-01-01

177

Ultra-high field magnetic resonance imaging of the basal ganglia and related structures  

PubMed Central

Deep brain stimulation is a treatment for Parkinson's disease and other related disorders, involving the surgical placement of electrodes in the deeply situated basal ganglia or thalamic structures. Good clinical outcome requires accurate targeting. However, due to limited visibility of the target structures on routine clinical MR images, direct targeting of structures can be challenging. Non-clinical MR scanners with ultra-high magnetic field (7T or higher) have the potential to improve the quality of these images. This technology report provides an overview of the current possibilities of visualizing deep brain stimulation targets and their related structures with the aid of ultra-high field MRI. Reviewed studies showed improved resolution, contrast- and signal-to-noise ratios at ultra-high field. Sequences sensitive to magnetic susceptibility such as T2* and susceptibility weighted imaging and their maps in general showed the best visualization of target structures, including a separation between the subthalamic nucleus and the substantia nigra, the lamina pallidi medialis and lamina pallidi incompleta within the globus pallidus and substructures of the thalamus, including the ventral intermediate nucleus (Vim). This shows that the visibility, identification, and even subdivision of the small deep brain stimulation targets benefit from increased field strength. Although ultra-high field MR imaging is associated with increased risk of geometrical distortions, it has been shown that these distortions can be avoided or corrected to the extent where the effects are limited. The availability of ultra-high field MR scanners for humans seems to provide opportunities for a more accurate targeting for deep brain stimulation in patients with Parkinson's disease and related disorders.

Plantinga, Birgit R.; Temel, Yasin; Roebroeck, Alard; Uluda?, Kmil; Ivanov, Dimo; Kuijf, Mark L.; ter Haar Romenij, Bart M.

2014-01-01

178

Clinico-radiological Characteristics of Spontaneous Basal Ganglia Hemorrhage, According to Regional Classification  

PubMed Central

Objective The clinico-radiologic features of the spontaneous basal ganglia hemorrhage (BGH) may often differ one from another, according to its regional location. Therefore, we attempted to classify the BGH into regional subgroups, and to extrapolate the distinct characteristics of each group of BGH. Materials and Methods A total of 103 BGHs were analyzed by retrospective review of medical records. BGH was classified according to four subgroups; anterior BGH; posterior BGH; lateral BGH; massive BGH. Results The most common BGH was the posterior BGH (56, 54.4%), followed by the lateral BGH (26, 25.2%), the massive BGH (12, 11.7%), and the anterior BGH (9, 8.7%). The shape of hemorrhage tended to be round in anterior, irregular in posterior, and ovoid in lateral BGH. A layered density of hematoma on initial computed tomography showed correlation with hematoma expansion (p = 0.016), which was observed more often in the postero-lateral group of BGH than in the anterior BGH group. Relatively better recovery from the initial insult was observed in the lateral BGH group than in the other regional BGH groups. The proportion of poor outcome (modified Rankin scale 4, 5, 6) was 100% in the massive, 41.1% in the posterior, 34.6% in the lateral, and 0% in the anterior BGH group. Conclusion We observed that BGH can be grouped according to its regional location and each group may have distinct characteristics. Thus, a more sophisticated clinical strategy tailored to each group of BGHs can be implemented. PMID:25340023

Kim, Do Young; Choo, Yeon Soo; Jang, E Wook; Chung, Joonho; Joo, Jin Yang

2014-01-01

179

Lack of depotentiation at basal ganglia output neurons in PD patients with levodopa-induced dyskinesia.  

PubMed

Parkinson's disease (PD), characterized by the loss of dopaminergic nigrostriatal projections, is a debilitating neurodegenerative disease which produces bradykinesia, rigidity, tremor and postural instability. The dopamine precursor levodopa (L-Dopa) is the most effective treatment for the amelioration of PD signs and symptoms, but long-term administration can lead to disabling motor fluctuations and L-Dopa-induced dyskinesias. In animal models of PD, a form of plasticity called depotentiation, or the reversal of previous potentiation, is selectively lost after the development of dyskinetic movements following L-Dopa treatment. We investigated whether low frequency stimulation (LFS) in the globus pallidus internus (GPi) and substantia nigra pars reticulata (SNr) could induce depotentiation at synapses that had already undergone high frequency stimulation (HFS)-induced potentiation. To do so, we measured the field potentials (fEPs) evoked by stimulation from a nearby microelectrode in 28 patients undergoing implantation of deep brain stimulating (DBS) electrodes in the subthalamic nucleus (STN) or GPi. We found that GPi and SNr synapses in patients with less severe dyskinesia underwent greater depotentiation following LFS than in patients with more severe dyskinesia. This demonstration of impaired depotentiation in basal ganglia output nuclei in PD patients with dyskinesia is an important validation of animal models of levodopa-induced dyskinesia. The ability of a synapse to reverse previous potentiation may be crucial to the normal function of the BG, perhaps by preventing saturation of the storage capacity required in motor learning and optimal motor function. Loss of this ability at the output nuclei may underlie, or contribute to the cellular basis of dyskinetic movements. PMID:25116960

Prescott, I A; Liu, L D; Dostrovsky, J O; Hodaie, M; Lozano, A M; Hutchison, W D

2014-11-01

180

Motor thalamus integration of cortical, cerebellar and basal ganglia information: implications for normal and parkinsonian conditions.  

PubMed

Motor thalamus (Mthal) is implicated in the control of movement because it is strategically located between motor areas of the cerebral cortex and motor-related subcortical structures, such as the cerebellum and basal ganglia (BG). The role of BG and cerebellum in motor control has been extensively studied but how Mthal processes inputs from these two networks is unclear. Specifically, there is considerable debate about the role of BG inputs on Mthal activity. This review summarizes anatomical and physiological knowledge of the Mthal and its afferents and reviews current theories of Mthal function by discussing the impact of cortical, BG and cerebellar inputs on Mthal activity. One view is that Mthal activity in BG and cerebellar-receiving territories is primarily "driven" by glutamatergic inputs from the cortex or cerebellum, respectively, whereas BG inputs are modulatory and do not strongly determine Mthal activity. This theory is steeped in the assumption that the Mthal processes information in the same way as sensory thalamus, through interactions of modulatory inputs with a single driver input. Another view, from BG models, is that BG exert primary control on the BG-receiving Mthal so it effectively relays information from BG to cortex. We propose a new "super-integrator" theory where each Mthal territory processes multiple driver or driver-like inputs (cortex and BG, cortex and cerebellum), which are the result of considerable integrative processing. Thus, BG and cerebellar Mthal territories assimilate motivational and proprioceptive motor information previously integrated in cortico-BG and cortico-cerebellar networks, respectively, to develop sophisticated motor signals that are transmitted in parallel pathways to cortical areas for optimal generation of motor programmes. Finally, we briefly review the pathophysiological changes that occur in the BG in parkinsonism and generate testable hypotheses about how these may affect processing of inputs in the Mthal. PMID:24273509

Bosch-Bouju, Clmentine; Hyland, Brian I; Parr-Brownlie, Louise C

2013-01-01

181

Neurobrucellosis with transient ischemic attack, vasculopathic changes, intracerebral granulomas and basal ganglia infarction: a case report  

PubMed Central

Introduction Central nervous system involvement is a rare but serious manifestation of brucellosis. We present an unusual case of neurobrucellosis with transient ischemic attack, intracerebral vasculopathy granulomas, seizures, and paralysis of sixth and seventh cranial nerves. Case presentation A 17-year-old Caucasian man presented with nausea and vomiting, headache, double vision and he gave a history of weakness in the left arm, speech disturbance and imbalance. Physical examination revealed fever, doubtful neck stiffness and left abducens nerve paralysis. An analysis of his cerebrospinal fluid showed a pleocytosis (lymphocytes, 90%), high protein and low glucose levels. He developed generalized tonic-clonic seizures, facial paralysis and left hemiparesis. Cranial magnetic resonance imaging demonstrated intracerebral vasculitis, basal ganglia infarction and granulomas, mimicking the central nervous system involvement of tuberculosis. On the 31st day of his admission, neurobrucellosis was diagnosed with immunoglobulin M and immunoglobulin G positivity by standard tube agglutination test and enzyme-linked immunosorbent assay in both serum and cerebrospinal fluid samples (the tests had been negative until that day). He was treated successfully with trimethoprim and sulfamethoxazole, doxycyline and rifampicin for six months. Conclusions Our patient illustrates the importance of suspecting brucellosis as a cause of meningoencephalitis, even if cultures and serological tests are negative at the beginning of the disease. As a result, in patients who have a history of residence or travel to endemic areas, neurobrucellosis should be considered in the differential diagnosis of any neurologic symptoms. If initial tests fail, repetition of these tests at appropriate intervals along with complementary investigations are indicated. PMID:20973948

2010-01-01

182

The basal ganglia are hyperactive during the discrimination of tactile stimuli in writer's cramp  

Microsoft Academic Search

Writer's cramp is a focal hand dystonia that specifically affects handwriting. Though writer's cramp has been attributedto adysfunctionof thebasal ganglia,theroleof thebasal ganglia inthepathogenesisofwriter'scramp remains to be determined. Seventeen patients with writer's cramp (nine females; age range: 24-71 years) and 17 healthy individuals (six females; age range: 27-68 years) underwent functional MRI (fMRI) while they dis- criminated the orientation of gratings

M. Peller; K. E. Zeuner; A. Munchau; A. Quartarone; M. Weiss; A. Knutzen; M. Hallett; G. Deuschl; H. R. Siebner

2006-01-01

183

Phenotyping dividing cells in mouse models of neurodegenerative basal ganglia diseases  

PubMed Central

Background Mice generated by a Cre/LoxP transgenic paradigm were used to model neurodegenerative basal ganglia disease of which Huntington disease (HD) is the prototypical example. In HD, death occurs in striatal projection neurons as well as cortical neurons. Cortical and striatal neurons that express the D1 dopamine receptor (Drd1a) degenerate in HD. The contribution that death of specific neuronal cell populations makes to the HD disease phenotype and the response of the brain to loss of defined cell subtypes is largely unknown. Methods Drd1a-expressing cells were targeted for cell death and three independent lines generated; a striatal-restricted line, a cortical-restricted line and a global line in which Drd1a cells were deleted from both the striatum and cortex. Two independent experimental approaches were used. In the first, the proliferative marker Ki-67 was used to identify proliferating cells in eighty-week-old mice belonging to a generic global line, a global in which Drd1a cells express green fluorescent protein (GFP-global) and in eighty-week-old mice of a cortical line. In the second experiment, the proliferative response of four-week-old mice belonging to GFP-global and striatal lines was assessed using the thymidine analogue BrdU. The phenotype of proliferating cells was ascertained by double staining for BrdU and Olig2 (an oligodendrocyte marker), Iba1 (a microglial cell marker), S100? (an astroglial cell marker), or NeuN (a neuronal cell marker). Results In the first study, we found that Ki-67-expressing cells were restricted to the striatal side of the lateral ventricles. Control mice had a greater number of Ki-67+ cells than mutant mice. There was no overlap between Ki-67 and GFP staining in control or mutant mice, suggesting that cells did not undergo cell division once they acquired a Drd1a phenotype. In contrast, in the second study we found that BrdU+ cells were identified throughout the cortex, striatum and periventricular region of control and mutant mice. Mutant mice from the GFP-global line showed increased BrdU+ cells in the cortex, striatum and periventricular region relative to control. Striatal line mutant mice had an increased number of BrdU+ cells in the striatum and periventricular region, but not the cortex. The number of microglia, astrocytes, oligodendrocytes and neurons generated from dividing progenitors was increased relative to control mice in most brain regions in mutant mice from the GFP-global line. In contrast, striatal line mutant mice displayed an increase only in the number of dividing microglia in striatal and periventricular regions. Conclusions Genetically programmed post-natal ablation of Drd1a-expressing neurons is associated with an extensive proliferative response involving multiple cell lineages. The nature of the tissue response has the potential not only to remove cellular debris but also to forge physiologically meaningful brain repair. Age related deficits in proliferation are seen in mutant lines. A blunted endogenous reparative response may underlie the cumulative deficits characteristic of age related neurodegeneration. PMID:24090101

2013-01-01

184

Delta-mediated cross-frequency coupling organizes oscillatory activity across the rat cortico-basal ganglia network  

PubMed Central

The brain's ability to integrate different behavioral and cognitive processes relies on its capacity to generate neural oscillations in a cooperative and coordinated manner. Cross-frequency coupling (CFC) has recently been proposed as one of the mechanisms involved in organizing brain activity. Here we investigated the phase-to-amplitude CFC (PA-CFC) patterns of the oscillatory activity in the cortico-basal ganglia network of healthy, freely moving rats. Within-structure analysis detected consistent PA-CFC patterns in the four regions analyzed, with the phase of delta waves modulating the amplitude of activity in the gamma (low-gamma ~50 Hz; high-gamma ~80 Hz) and high frequency ranges (high frequency oscillations HFO, ~150 Hz). Between-structure analysis revealed that the phase of delta waves parses the occurrence of transient episodes of coherence in the gamma and high frequency bands across the entire network, providing temporal windows of coherence between different structures. Significantly, this specific spatio-temporal organization was affected by the action of dopaminergic drugs. Taken together, our findings suggest that delta-mediated PA-CFC plays a key role in the organization of local and distant activities in the rat cortico-basal ganglia network by fine-tuning the timing of synchronization events across different structures. PMID:24106462

Lopez-Azcarate, Jon; Nicolas, Maria Jesus; Cordon, Ivan; Alegre, Manuel; Valencia, Miguel; Artieda, Julio

2013-01-01

185

Alterations in the basal ganglia in patients with brain tumours may be due to excessive iron deposition  

PubMed Central

The accumulation of iron in the brain is a common physiological process. However, alterations in the deposition of iron or other paramagnetic substances are associated with various diseases. In the present study, the deposition of paramagnetic substances in patients with brain tumours was evaluated using T2 relaxometry. A total of 23 patients with untreated tumours or with recurrent tumours following treatment, together with a group of 19 age-matched healthy controls, were examined using T2 relaxometry at 3T. The relaxation times in the basal ganglia, thalamus and white matter were evaluated. Significantly lower T2 relaxation times were identified in the basal ganglia and thalamus of the patients with tumours, as compared with those of the controls (P<0.05). No statistically significant difference was identified between patients with untreated or recurrent brain tumours. The reduction in T2 relaxation times in the brain tumour patients was possibly caused by the accumulation of iron, since iron homeostasis is known to be altered in patients with tumours. We propose that increased iron deposition is a consequence of a higher risk of oxidative stress caused by an increased iron concentration in the plasma or cerebrospinal fluid.

HERYNEK, VT; WAGNEROV, DITA; MALUCELLI, ALBERTO; VYMAZAL, JOSEF; SAME, MARTIN; HJEK, MILAN

2015-01-01

186

Effective deep brain stimulation suppresses low frequency network oscillations in the basal ganglia by regularizing neural firing patterns  

PubMed Central

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for the motor symptoms of Parkinsons disease (PD). The effects of DBS depend strongly on stimulation frequency: high frequencies (>90Hz) improve motor symptoms, while low frequencies (<50Hz) are either ineffective or exacerbate symptoms. The neuronal basis for these frequency-dependent effects of DBS is unclear. The effects of different frequencies of STN-DBS on behavior and single-unit neuronal activity in the basal ganglia were studied in the unilateral 6-hydroxydopamine lesioned rat model of PD. Only high frequency DBS reversed motor symptoms and the effectiveness of DBS depended strongly on stimulation frequency in a manner reminiscent of its clinical effects in persons with PD. Quantification of single-unit activity in the globus pallidus externa (GPe) and substantia nigra reticulata (SNr) revealed that high frequency DBS, but not low frequency DBS, reduced pathological low frequency oscillations (~9Hz) and entrained neurons to fire at the stimulation frequency. Similarly, the coherence between simultaneously recorded pairs of neurons within and across GPe and SNr shifted from the pathological low frequency band to the stimulation frequency during high frequency DBS, but not during low frequency DBS. The changes in firing patterns in basal ganglia neurons were not correlated with changes in firing rate. These results indicate that high frequency DBS is more effective than low frequency DBS, not as a result of changes in firing rate, but rather due to its ability to replace pathological low frequency network oscillations with a regularized pattern of neuronal firing. PMID:23136407

McConnell, George C.; So, Rosa Q.; Hilliard, Justin D; Lopomo, Paola; Grill, Warren M.

2012-01-01

187

Basal ganglia stroke due to mild head trauma in pediatric age - clinical and therapeutic management: a case report and 10 year literature review  

Microsoft Academic Search

Ischemia of the basal ganglia as an immediate consequence of minor head injury in children is rare (< 2% of all ischemic stroke in childhood) and is due to vasospasm of the lenticulostriate arteries. The clinical history of these lesions is particularly favourable because they are usually small, and also because the facial-brachial-crural hemiparesis typical of this pathology usually regresses

Alessandro Landi; Nicola Marotta; Cristina Mancarella; Daniele Marruzzo; Maurizio Salvati; Roberto Delfini

2011-01-01

188

Temporal Coupling with Cortex Distinguishes Spontaneous Neuronal Activities in Identified Basal Ganglia-Recipient and Cerebellar-Recipient Zones of the Motor Thalamus  

PubMed Central

Neurons of the motor thalamus mediate basal ganglia and cerebellar influences on cortical activity. To elucidate the net result of ?-aminobutyric acid-releasing or glutamatergic bombardment of the motor thalamus by basal ganglia or cerebellar afferents, respectively, we recorded the spontaneous activities of thalamocortical neurons in distinct identified input zones in anesthetized rats during defined cortical activity states. Unexpectedly, the mean rates and brain state dependencies of the firing of neurons in basal ganglia-recipient zone (BZ) and cerebellar-recipient zone (CZ) were matched during slow-wave activity (SWA) and cortical activation. However, neurons were distinguished during SWA by their firing regularities, low-threshold spike bursts and, more strikingly, by the temporal coupling of their activities to ongoing cortical oscillations. The firing of neurons across the BZ was stronger and more precisely phase-locked to cortical slow (?1 Hz) oscillations, although both neuron groups preferentially fired at the same phase. In contrast, neurons in BZ and CZ fired at different phases of cortical spindles (712 Hz), but with similar strengths of coupled firing. Thus, firing rates do not reflect the predicted inhibitoryexcitatory imbalance across the motor thalamus, and input zone-specific temporal coding through oscillatory synchronization with the cortex could partly mediate the different roles of basal ganglia and cerebellum in behavior. PMID:23042738

Nakamura, Kouichi C.; Sharott, Andrew; Magill, Peter J.

2014-01-01

189

Basal Ganglia Play a Unique Role in Task Switching within the Frontal-Subcortical Circuits: Evidence from Patients with Focal Lesions  

Microsoft Academic Search

The performance of patients with lesions involving the basal ganglia (BG) was compared to that of patients with prefrontal (PFC) lesions, thalamic (TH) lesions, and age-matched controls in order to examine the specific role of the BG within the frontal-subcortical circuits (FSCC) in task switching. All the BG patients and none of the other participants showed a marked increase in

Einat Yehene; Nachshon Meiran; Nachum Soroker

2008-01-01

190

BASAL GANGLIA NEURAL CODING OF NATURAL ACTION SEQUENCES 65 * J.W. Aldridge, Department of Neurology, Department of Psychology, University of Michigan. K.C.  

E-print Network

and the tormenting habits and thoughts of obsessive compulsive disorder32 , both of which are associated disorders of the basal ganglia strongly supports a motor function. However, close scrutiny suggests, organisational aspect of motor control is disturbed by this disorder. Huntington's patients have been shown

Berridge, Kent

191

What can man do without basal ganglia motor output? The effect of combined unilateral subthalamotomy and pallidotomy in a patient with Parkinson's disease  

Microsoft Academic Search

We have studied motor performance in a man with Parkinson's disease (PD) in whom thermolytic lesions of the left subthalamic and left globus pallidus nuclei interrupted the basal ganglia (BG)-thalamo-cortical motor circuit in the left hemisphere. This allowed us to study remaining motor capabilities in the absence of aberrant BG activity typical of PD. Movements of the left arm were

J. A. Obeso; M. Jahanshahi; L. Alvarez; R. Macias; I. Pedroso; L. Wilkinson; N. Pavon; B. Day; S. Pinto; M. C. Rodrguez-Oroz; J. Tejeiro; J. Artieda; P. Talelli; O. Swayne; R. Rodrguez; K. Bhatia; M. Rodriguez-Diaz; G. Lopez; J. Guridi; J. C. Rothwell

2009-01-01

192

IP3R1 deficiency in the cerebellum/brainstem causes basal ganglia-independent dystonia by triggering tonic Purkinje cell firings in mice  

PubMed Central

The type 1 inositol 1,4,5- trisphosphate receptor (IP3R1) is a Ca2+ channel on the endoplasmic reticulum and is a predominant isoform in the brain among the three types of IP3Rs. Mice lacking IP3R1 show seizure-like behavior; however the cellular and neural circuit mechanism by which IP3R1 deletion causes the abnormal movements is unknown. Here, we found that the conditional knockout mice lacking IP3R1 specifically in the cerebellum and brainstem experience dystonia and show that cerebellar Purkinje cell (PC) firing patterns were coupled to specific dystonic movements. Recordings in freely behaving mice revealed epochs of low and high frequency PC complex spikes linked to body extension and rigidity, respectively. Remarkably, dystonic symptoms were independent of the basal ganglia, and could be rescued by inactivation of the cerebellum, inferior olive or in the absence of PCs. These findings implicate IP3R1-dependent PC firing patterns in cerebellum in motor coordination and the expression of dystonia through the olivo-cerebellar pathway. PMID:24109434

Hisatsune, Chihiro; Miyamoto, Hiroyuki; Hirono, Moritoshi; Yamaguchi, Naohide; Sugawara, Takeyuki; Ogawa, Naoko; Ebisui, Etsuko; Ohshima, Toshio; Yamada, Masahisa; Hensch, Takao K.; Hattori, Mitsuharu; Mikoshiba, Katsuhiko

2013-01-01

193

Temporal Changes of CB1 Cannabinoid Receptor in the Basal Ganglia as a Possible Structure-Specific Plasticity Process in 6-OHDA Lesioned Rats  

PubMed Central

The endocannabinoid system has been implicated in several neurobiological processes, including neurodegeneration, neuroprotection and neuronal plasticity. The CB1 cannabinoid receptors are abundantly expressed in the basal ganglia, the circuitry that is mostly affected in Parkinsons Disease (PD). Some studies show variation of CB1 expression in basal ganglia in different animal models of PD, however the results are quite controversial, due to the differences in the procedures employed to induce the parkinsonism and the periods analyzed after the lesion. The present study evaluated the CB1 expression in four basal ganglia structures, namely striatum, external globus pallidus (EGP), internal globus pallidus (IGP) and substantia nigra pars reticulata (SNpr) of rats 1, 5, 10, 20, and 60 days after unilateral intrastriatal 6-hydroxydopamine injections, that causes retrograde dopaminergic degeneration. We also investigated tyrosine hydroxylase (TH), parvalbumin, calbindin and glutamic acid decarboxylase (GAD) expression to verify the status of dopaminergic and GABAergic systems. We observed a structure-specific modulation of CB1 expression at different periods after lesions. In general, there were no changes in the striatum, decreased CB1 in IGP and SNpr and increased CB1 in EGP, but this increase was not sustained over time. No changes in GAD and parvalbumin expression were observed in basal ganglia, whereas TH levels were decreased and the calbindin increased in striatum in short periods after lesion. We believe that the structure-specific variation of CB1 in basal ganglia in the 6-hydroxydopamine PD model could be related to a compensatory process involving the GABAergic transmission, which is impaired due to the lack of dopamine. Our data, therefore, suggest that the changes of CB1 and calbindin expression may represent a plasticity process in this PD model. PMID:24116178

Chaves-Kirsten, Gabriela P.; Mazucanti, Caio H. Y.; Real, Caroline C.; Souza, Bruna M.; Britto, Luiz R. G.; Torrao, Andrea S.

2013-01-01

194

Basal ganglia oscillations: the role of delays and external excitatory nuclei  

E-print Network

in the beta band (13-30Hz) is known to be linked to Parkinson's disease motor symptoms. In this paper, we in connection with a variety of pathological observations such as Parkinson's disease [23]. Some evidence suggests that the advance of parkinsonism is highly correlated to the presence of abnormal oscillations

Boyer, Edmond

195

Oculomotor learning revisited: a model of reinforcement learning in the basal ganglia incorporating an efference copy of motor actions  

PubMed Central

In its simplest formulation, reinforcement learning is based on the idea that if an action taken in a particular context is followed by a favorable outcome, then, in the same context, the tendency to produce that action should be strengthened, or reinforced. While reinforcement learning forms the basis of many current theories of basal ganglia (BG) function, these models do not incorporate distinct computational roles for signals that convey context, and those that convey what action an animal takes. Recent experiments in the songbird suggest that vocal-related BG circuitry receives two functionally distinct excitatory inputs. One input is from a cortical region that carries context information about the current time in the motor sequence. The other is an efference copy of motor commands from a separate cortical brain region that generates vocal variability during learning. Based on these findings, I propose here a general model of vertebrate BG function that combines context information with a distinct motor efference copy signal. The signals are integrated by a learning rule in which efference copy inputs gate the potentiation of context inputs (but not efference copy inputs) onto medium spiny neurons in response to a rewarded action. The hypothesis is described in terms of a circuit that implements the learning of visually guided saccades. The model makes testable predictions about the anatomical and functional properties of hypothesized context and efference copy inputs to the striatum from both thalamic and cortical sources. PMID:22754501

Fee, Michale S.

2012-01-01

196

Oculomotor learning revisited: a model of reinforcement learning in the basal ganglia incorporating an efference copy of motor actions.  

PubMed

In its simplest formulation, reinforcement learning is based on the idea that if an action taken in a particular context is followed by a favorable outcome, then, in the same context, the tendency to produce that action should be strengthened, or reinforced. While reinforcement learning forms the basis of many current theories of basal ganglia (BG) function, these models do not incorporate distinct computational roles for signals that convey context, and those that convey what action an animal takes. Recent experiments in the songbird suggest that vocal-related BG circuitry receives two functionally distinct excitatory inputs. One input is from a cortical region that carries context information about the current "time" in the motor sequence. The other is an efference copy of motor commands from a separate cortical brain region that generates vocal variability during learning. Based on these findings, I propose here a general model of vertebrate BG function that combines context information with a distinct motor efference copy signal. The signals are integrated by a learning rule in which efference copy inputs gate the potentiation of context inputs (but not efference copy inputs) onto medium spiny neurons in response to a rewarded action. The hypothesis is described in terms of a circuit that implements the learning of visually guided saccades. The model makes testable predictions about the anatomical and functional properties of hypothesized context and efference copy inputs to the striatum from both thalamic and cortical sources. PMID:22754501

Fee, Michale S

2012-01-01

197

Emotional blunting following left basal ganglia stroke: The role of depression and fronto-limbic functional alterations  

PubMed Central

Disorders of the basal ganglia (BG) alter perception and experience of emotions. Left hemisphere BG (LBG) stroke is also associated with depression. The interplay between depression and alterations in emotional processing following LBG stroke was examined. Evoked affective responses to emotion-laden pictorial stimuli were compared among LBG stroke and healthy participants and participants with stroke damage in brain regions not including the LBG selected to equate depression severity (measured using the Hamilton Depression Scale) with LBG damage participants. Brain activity {[O15]water PET} was measured in LBG stroke relative to healthy participants to identify changes in regions associated with emotion processing and depression. LBG stroke subjects reported less intense emotions compared with healthy, but not stroke comparison participants. Depression negatively correlated with emotional experience for positive and negative emotions. In response to positive stimuli, LBG subjects exhibited higher activity in amygdala, anterior cingulate, dorsal prefrontal cortex, and insula compared to healthy volunteers. In response to negative stimuli, LBG subjects demonstrated lower activity in right frontal-polar region and fusiform gyrus. Higher baseline activity in amygdala and ventral and mesial prefrontal cortex and lower activity in left dorsal lateral prefrontal cortex were associated with higher depression scores. LBG stroke led to blunted emotions, and brain activity alterations accounting for reduced affective experience, awareness and depression. Depression and fronto-limbic activity changes may contribute to emotional blunting following LBG stroke. PMID:23176970

Paradiso, Sergio; Ostedgaard, Katharine; Vaidya, Jatin; Ponto, Laura Boles; Robinson, Robert

2014-01-01

198

Transsylvian-Transinsular Approaches to the Insula and Basal Ganglia: Operative Techniques and Results with Vascular Lesions  

PubMed Central

BACKGROUND Lesions in the insula and basal ganglia can be risky to resect due to their depth and proximity to critical structures, particularly in the dominant hemisphere. Transsylvian approaches shorten the surgical distance to these lesions, preserve perisylvian temporal and frontal cortex, and minimize brain transgression. OBJECTIVE We report our experience with transsylvian-transinsular approaches to vascular lesions. METHODS The anterior approach opened the sphenoidal and insular portions of the Sylvian fissure and exposed the limen insulae and short gyri, whereas the posterior approach opened the insular and opercular portions of the Sylvian fissure and exposed the circular sulcus and long gyri. RESULTS 41 patients with vascular lesions (24 arteriovenous malformations (AVM) and 17 cavernous amlformations (CM)) were treated surgically with a transsylvian-transinsular approach. Complete resection was obtained in 87.5% of AVMs and 95% of CMs. Permanent neurologic morbidity related to surgery was observed in 2 AVM patients (5%), with the remaining 39 patients (95%) improved or unchanged postoperatively (modified Rankin Scale scores 02 in 83%). There were no new language deficits in patients with dominant hemisphere lesions. CONCLUSION Transsylvian-transinsular approaches safely expose vascular pathology in or deep to the insula while preserving overlying eloquent cortex in the frontal and temporal lobes. The anterior transsylvian-transinsular approach can be differentiated from the posterior approach based on technical differences in splitting the Sylvian fissure and anatomical differences in final exposure. Discriminating patient selection and careful microsurgical technique are essential. PMID:21937930

Potts, Matthew B.; Chang, Edward F.; Young, William L.; Lawton, Michael T.

2011-01-01

199

Ensemble neural activity of the frontal cortical basal ganglia system predicts reaction time task performance in rats.  

PubMed

The question pursued in this study was when neural activity appears in the cortico-basal ganglia system that could predict alternate behavioral responses in a reaction time (RT) task. In this protocol, rats first performed a nose poke to initiate a trial, depressed a lever when presented, and then released the lever after a tone cue. Multiple-channel, single-unit recordings (up to 62 units) were obtained simultaneously from the prefrontal cortex, the dorsal medial striatum, the globus pallidus, and the substantia nigra pars reticulata in a single rat during a session. Results indicated that (1) global alterations of neural activity appeared in clusters, which was associated with different behavioral components and observed in each of the targeted areas; (2) small independent subsets of neurons responded differently between error (lever was released before tone presentation) and correct trials (lever was released within 0.5s after tone onset) during these behavioral episodes; (3) significant correlations between RTs and single units activities were found in the early preparation phases of the task. The results reveal that complex early preparatory activity exists several seconds before the final movements in a RT task, which may determine executive functions leading to rapid decoding of alternate behavioral performances. PMID:21781993

Li, Xianghong; Luo, Fei; Shi, Lihong; Woodward, Donald J; Chang, Jingyu

2011-10-01

200

Reduced Topological Efficiency in Cortical-Basal Ganglia Motor Network of Parkinson's Disease: A Resting State fMRI Study  

PubMed Central

Parkinson's disease (PD) is mainly characterized by dopamine depletion of the cortico-basal ganglia (CBG) motor circuit. Given that dopamine dysfunction could affect functional brain network efficiency, the present study utilized resting-state fMRI (rs-fMRI) and graph theoretical approach to investigate the topological efficiency changes of the CBG motor network in patients with PD during a relatively hypodopaminergic state (12 hours after a last dose of dopamimetic treatment). We found that PD compared with controls had remarkable decreased efficiency in the CBG motor network, with the most pronounced changes observed in rostral supplementary motor area (pre-SMA), caudal SMA (SMA-proper), primary motor cortex (M1), primary somatosensory cortex (S1), thalamus (THA), globus pallidus (GP), and putamen (PUT). Furthermore, reduced efficiency in pre-SMA, M1, THA and GP was significantly correlated with Unified Parkinson's Disease Rating Scale (UPDRS) motor scores in PD patients. Together, our results demonstrate that individuals with PD appear to be less effective at information transfer within the CBG motor pathway, which provides a novel perspective on neurobiological explanation for the motor symptoms in patients. These findings are in line with the pathophysiology of PD, suggesting that network efficiency metrics may be used to identify and track the pathology of PD. PMID:25279557

Long, Zhiliang; Wu, Guo-Rong; Hu, Xiaofei; Zhang, Yanling; Wang, Jian

2014-01-01

201

The Allocation of Attention to Learning of Goal-Directed Actions: A Cognitive Neuroscience Framework Focusing on the Basal Ganglia  

PubMed Central

The present paper builds on the idea that attention is largely in service of our actions. A framework and model which captures the allocation of attention for learning of goal-directed actions is proposed and developed. This framework highlights an evolutionary model based on the notion that rudimentary functions of the basal ganglia have become embedded into increasingly higher levels of networks which all contribute to adaptive learning. Supporting the proposed model, background literature is presented alongside key evidence based on experimental studies in the so-called split-brain (surgically divided cerebral hemispheres), and selected evidence from related areas of research. Although overlap with other existing findings and models is acknowledged, the proposed framework is an original synthesis of cognitive experimental findings with supporting evidence of a neural system and a carefully formulated model of attention. It is the hope that this new synthesis will be informative in fields of cognition and other fields of brain sciences and will lead to new avenues for experimentation across domains. PMID:23267335

Franz, E. A.

2012-01-01

202

Exploring the cognitive and motor functions of the basal ganglia: an integrative review of computational cognitive neuroscience models  

PubMed Central

Many computational models of the basal ganglia (BG) have been proposed over the past twenty-five years. While computational neuroscience models have focused on closely matching the neurobiology of the BG, computational cognitive neuroscience (CCN) models have focused on how the BG can be used to implement cognitive and motor functions. This review article focuses on CCN models of the BG and how they use the neuroanatomy of the BG to account for cognitive and motor functions such as categorization, instrumental conditioning, probabilistic learning, working memory, sequence learning, automaticity, reaching, handwriting, and eye saccades. A total of 19 BG models accounting for one or more of these functions are reviewed and compared. The review concludes with a discussion of the limitations of existing CCN models of the BG and prescriptions for future modeling, including the need for computational models of the BG that can simultaneously account for cognitive and motor functions, and the need for a more complete specification of the role of the BG in behavioral functions. PMID:24367325

Helie, Sebastien; Chakravarthy, Srinivasa; Moustafa, Ahmed A.

2013-01-01

203

Neuromodulatory adaptive combination of correlation-based learning in cerebellum and reward-based learning in basal ganglia for goal-directed behavior control  

PubMed Central

Goal-directed decision making in biological systems is broadly based on associations between conditional and unconditional stimuli. This can be further classified as classical conditioning (correlation-based learning) and operant conditioning (reward-based learning). A number of computational and experimental studies have well established the role of the basal ganglia in reward-based learning, where as the cerebellum plays an important role in developing specific conditioned responses. Although viewed as distinct learning systems, recent animal experiments point toward their complementary role in behavioral learning, and also show the existence of substantial two-way communication between these two brain structures. Based on this notion of co-operative learning, in this paper we hypothesize that the basal ganglia and cerebellar learning systems work in parallel and interact with each other. We envision that such an interaction is influenced by reward modulated heterosynaptic plasticity (RMHP) rule at the thalamus, guiding the overall goal directed behavior. Using a recurrent neural network actor-critic model of the basal ganglia and a feed-forward correlation-based learning model of the cerebellum, we demonstrate that the RMHP rule can effectively balance the outcomes of the two learning systems. This is tested using simulated environments of increasing complexity with a four-wheeled robot in a foraging task in both static and dynamic configurations. Although modeled with a simplified level of biological abstraction, we clearly demonstrate that such a RMHP induced combinatorial learning mechanism, leads to stabler and faster learning of goal-directed behaviors, in comparison to the individual systems. Thus, in this paper we provide a computational model for adaptive combination of the basal ganglia and cerebellum learning systems by way of neuromodulated plasticity for goal-directed decision making in biological and bio-mimetic organisms. PMID:25389391

Dasgupta, Sakyasingha; Worgotter, Florentin; Manoonpong, Poramate

2014-01-01

204

Loss of cannabinoid CB 1 receptors in the basal ganglia in the late akinetic phase of rats with experimental Huntingtons disease  

Microsoft Academic Search

We have recently examined the status of the endocannabinoid transmission in the basal ganglia in Huntingtons disease (HD)\\u000a using a rat model generated by bilateral intrastriatal injections of 3-nitropropionic acid (3-NP). In these previous studies,\\u000a we focused on the early phase of hyperactivity that occurs 12 weeks after the lesion, comparable to early grades of the human\\u000a disease, while in

Isabel Lastres-Becker; Mara Gmez; Rosario de Miguel; Jos A. Ramos; Javier Fernndez-Ruiz

2002-01-01

205

Common features of neural activity during singing and sleep periods in a basal ganglia nucleus critical for vocal learning in a juvenile songbird.  

PubMed

Reactivations of waking experiences during sleep have been considered fundamental neural processes for memory consolidation. In songbirds, evidence suggests the importance of sleep-related neuronal activity in song system motor pathway nuclei for both juvenile vocal learning and maintenance of adult song. Like those in singing motor nuclei, neurons in the basal ganglia nucleus Area X, part of the basal ganglia-thalamocortical circuit essential for vocal plasticity, exhibit singing-related activity. It is unclear, however, whether Area X neurons show any distinctive spiking activity during sleep similar to that during singing. Here we demonstrate that, during sleep, Area X pallidal neurons exhibit phasic spiking activity, which shares some firing properties with activity during singing. Shorter interspike intervals that almost exclusively occurred during singing in awake periods were also observed during sleep. The level of firing variability was consistently higher during singing and sleep than during awake non-singing states. Moreover, deceleration of firing rate, which is considered to be an important firing property for transmitting signals from Area X to the thalamic nucleus DLM, was observed mainly during sleep as well as during singing. These results suggest that songbird basal ganglia circuitry may be involved in the off-line processing potentially critical for vocal learning during sensorimotor learning phase. PMID:21991379

Yanagihara, Shin; Hessler, Neal A

2011-01-01

206

Model-Based Analysis and Control of a Network of Basal Ganglia Spiking Neurons in the Normal and Parkinsonian States  

PubMed Central

Controlling the spatiotemporal firing pattern of an intricately connected network of neurons through microstimulation is highly desirable in many applications. We investigated in this paper the feasibility of using a model-based approach to the analysis and control of a Basal Ganglia (BG) network model of HodgkinHuxley (HH) spiking neurons through microstimulation. Detailed analysis of this network model suggests that it can reproduce the experimentally observed characteristics of BG neurons under a normal and a pathological Parkinsonian state. A simplified neuronal firing rate model, identified from the detailed HH network model, is shown to capture the essential network dynamics. Mathematical analysis of the simplified model reveals the presence of a systematic relationship between the networks structure and its dynamic response to spatiotemporally patterned microstimulation. We show that both the network synaptic organization and the local mechanism of microstimulation can impose tight constraints on the possible spatiotemporal firing patterns that can be generated by the microstimulated network, which may hinder the effectiveness of microstimulation to achieve a desired objective under certain conditions. Finally, we demonstrate that the feedback control design aided by the mathematical analysis of the simplified model is indeed effective in driving the BG network in the normal and Parskinsonian states to follow a prescribed spatiotemporal firing pattern. We further show that the rhythmic/oscillatory patterns that characterize a dopamine-depleted BG network can be suppressed as a direct consequence of controlling the spatiotemporal pattern of a subpopulation of the output Globus Pallidus internalis (GPi) neurons in the network. This work may provide plausible explanations for the mechanisms underlying the therapeutic effects of Deep Brain Stimulation (DBS) in PD and pave the way towards a model-based, network level analysis and closed-loop control and optimization of DBS parameters, among many other applications. PMID:21775788

Liu, Jianbo; Khalil, Hassan K.; Oweiss, Karim G.

2011-01-01

207

Elucidating information processing in primate basal ganglia circuitry: a novel technique for pathway-selective ablation mediated by immunotoxin.  

PubMed

Employing a neuron-specific retrograde gene-transfer vector (NeuRet vector), we have recently developed a novel technique that achieves pathway-selective ablation in the primate brain. This technique is mediated by immunotoxin (IT) and eliminates a neuronal population that constitutes a particular pathway, leaving other pathways intact. By means of this technique, we have made an attempt to remove the hyperdirect pathway selectively from basal ganglia circuitry. The hyperdirect pathway links the motor cortex to the subthalamic nucleus (STN) directly and plays a crucial role in motor control. After electrical stimulation in the motor cortex, triphasic responses consisting of an early excitation, an inhibition, and a late excitation are usually elicited in the internal pallidal segment (GPi). Several pieces of pharmacophysiological evidence imply that the early excitation may be derived from the hyperdirect pathway. In our experiments, the NeuRet vector expressing human interleukin-2 receptor ?-subunit was injected into the STN of macaque monkeys. Then, IT injections were performed into the supplementary motor area (SMA). When single neuron activity in the GPi was recorded in response to the SMA stimulation, it was found that the early excitation was significantly reduced with neither the inhibition nor the late excitation affected. The spontaneous firing rate and pattern of GPi neurons remained to be altered. This clearly indicates that IT-mediated tract targeting successfully eliminated the hyperdirect pathway with spontaneous activity of STN neurons unaffected. The electrophysiological findings were histologically confirmed by retrograde and anterograde neuronal labeling. The overall data define that the motor cortically driven early excitation in GPi neurons is conveyed through the hyperdirect pathway. The IT-mediated pathway-selective ablation technique will provide a powerful tool for elucidating information processing in various neural networks. PMID:24027499

Takada, Masahiko; Inoue, Ken-Ichi; Koketsu, Daisuke; Kato, Shigeki; Kobayashi, Kazuto; Nambu, Atsushi

2013-01-01

208

Emergent structured transition from variation to repetition in a biologically-plausible model of learning in basal ganglia  

PubMed Central

Often, when animals encounter an unexpected sensory event, they transition from executing a variety of movements to repeating the movement(s) that may have caused the event. According to a recent theory of action discovery (Redgrave and Gurney, 2006), repetition allows the animal to represent those movements, and the outcome, as an action for later recruitment. The transition from variation to repetition often follows a non-random, structured, pattern. While the structure of the pattern can be explained by sophisticated cognitive mechanisms, simpler mechanisms based on dopaminergic modulation of basal ganglia (BG) activity are thought to underlie action discovery (Redgrave and Gurney, 2006). In this paper we ask the question: can simple BG-mediated mechanisms account for a structured transition from variation to repetition, or are more sophisticated cognitive mechanisms always necessary? To address this question, we present a computational model of BG-mediated biasing of behavior. In our model, unlike most other models of BG function, the BG biases behavior through modulation of cortical response to excitation; many possible movements are represented by the cortical area; and excitation to the cortical area is topographically-organized. We subject the model to simple reaching tasks, inspired by behavioral studies, in which a location to which to reach must be selected. Locations within a target area elicit a reinforcement signal. A structured transition from variation to repetition emerges from simple BG-mediated biasing of cortical response to excitation. We show how the structured pattern influences behavior in simple and complicated tasks. We also present analyses that describe the structured transition from variation to repetition due to BG-mediated biasing and from biasing that would be expected from a type of cognitive biasing, allowing us to compare behavior resulting from these types of biasing and make connections with future behavioral experiments. PMID:24575067

Shah, Ashvin; Gurney, Kevin N.

2014-01-01

209

Cortico-basal ganglia networks subserving goal-directed behavior mediated by conditional visuo-goal association  

PubMed Central

Action is often executed according to information provided by a visual signal. As this type of behavior integrates two distinct neural representations, perception and action, it has been thought that identification of the neural mechanisms underlying this process will yield deeper insights into the principles underpinning goal-directed behavior. Based on a framework derived from conditional visuomotor association, prior studies have identified neural mechanisms in the dorsal premotor cortex (PMd), dorsolateral prefrontal cortex (dlPFC), ventrolateral prefrontal cortex (vlPFC), and basal ganglia (BG). However, applications resting solely on this conceptualization encounter problems related to generalization and flexibility, essential processes in executive function, because the association mode involves a direct one-to-one mapping of each visual signal onto a particular action. To overcome this problem, we extend this conceptualization and postulate a more general framework, conditional visuo-goal association. According to this new framework, the visual signal identifies an abstract behavioral goal, and an action is subsequently selected and executed to meet this goal. Neuronal activity recorded from the four key areas of the brains of monkeys performing a task involving conditional visuo-goal association revealed three major mechanisms underlying this process. First, visual-object signals are represented primarily in the vlPFC and BG. Second, all four areas are involved in initially determining the goals based on the visual signals, with the PMd and dlPFC playing major roles in maintaining the salience of the goals. Third, the cortical areas play major roles in specifying action, whereas the role of the BG in this process is restrictive. These new lines of evidence reveal that the four areas involved in conditional visuomotor association contribute to goal-directed behavior mediated by conditional visuo-goal association in an area-dependent manner. PMID:24155692

Hoshi, Eiji

2013-01-01

210

Endocannabinoids mediate synaptic plasticity at glutamatergic synapses on spiny neurons within a basal ganglia nucleus necessary for song learning  

PubMed Central

Activation of type 1 cannabinoid receptors (CB1R) in many central nervous system structures induces both short- and long-term changes in synaptic transmission. Within mammalian striatum, endocannabinoids (eCB) are one of several mechanisms that induce synaptic plasticity at glutamatergic terminals onto medium spiny neurons. Striatal synaptic plasticity may contribute a critical component of adaptive motor coordination and procedural learning. Songbirds are advantageous for studying the neural mechanisms of motor learning because they possess a neural pathway necessary for song learning and adult song plasticity that includes a striato-pallidal nucleus, area X (homologous to a portion of mammalian basal ganglia). Recent findings suggest that eCBs contribute to vocal development. For example, dense CB1R expression in song control nuclei peaks around the closure of the sensori-motor integration phase of song development. Also, systemic administration of a CB1R agonist during vocal development impairs song learning. Here we test whether activation of CB1R alters excitatory synaptic input on spiny neurons in area X of adult male zebra finches. Application of the CB1R agonist WIN552122 decreased excitatory postsynaptic current (EPSC) amplitude; that decrease was blocked by the CB1R antagonist AM251. Guided by eCB experiments in mammalian striatum, we tested and verified that at least two mechanisms indirectly activate CB1Rs through eCBs in area X. First, activation of group I metabotropic glutamate receptors with the agonist 3,5-dihydroxyphenylglycine (DHPG) induced a CB1R-mediated reduction in EPSC amplitude. Second, we observed that a 10 s postsynaptic depolarization induced a calcium-mediated, eCB-dependent decrease in synaptic strength that resisted rescue with late CB1R blockade. Together, these results show that eCB modulation occurs at inputs to area X spiny neurons and could influence motor learning and production. PMID:21177997

Thompson, John A.

2011-01-01

211

Effects of levodopa on endocannabinoid levels in rat basal ganglia: implications for the treatment of levodopa-induced dyskinesias.  

PubMed

The majority of Parkinson's disease patients undergoing levodopa therapy develop disabling motor complications (dyskinesias) within 10 years of treatment. Stimulation of cannabinoid receptors, the pharmacological target of Delta 9-tetrahydrocannabinol, is emerging as a promising therapy to alleviate levodopa-associated dyskinesias. However, the mechanisms underlying this beneficial action remain elusive, as do the effects exerted by levodopa therapy on the endocannabinoid system. Although levodopa is known to cause changes in CB1 receptor expression in animal models of Parkinson's disease, we have no information on whether this drug alters the brain concentrations of the endocannabinoids anandamide and 2-arachidonylglycerol. To address this question, we used an isotope dilution assay to measure endocannabinoid levels in the caudate-putamen, globus pallidus and substantia nigra of intact and unilaterally 6-OHDA-lesioned rats undergoing acute or chronic treatment with levodopa (50 mg/kg). In intact animals, systemic administration of levodopa increased anandamide concentrations throughout the basal ganglia via activation of dopamine D1/D2 receptors. In 6-OHDA-lesioned rats, anandamide levels were significantly reduced in the caudate-putamen ipsilateral to the lesion; however, neither acute nor chronic levodopa treatment affected endocannabinoid levels in these animals. In lesioned rats, chronic levodopa produced increasingly severe oro-lingual involuntary movements which were attenuated by the cannabinoid agonist R(+)-WIN55,212-2 (1 mg/kg). This effect was reversed by the CB1 receptor antagonist rimonabant (SR141716A). These results indicate that a deficiency in endocannabinoid transmission may contribute to levodopa-induced dyskinesias and that these complications may be alleviated by activation of CB1 receptors. PMID:14511339

Ferrer, Belen; Asbrock, Nick; Kathuria, Satish; Piomelli, Daniele; Giuffrida, Andrea

2003-09-01

212

Temporal Sequence of Ictal discharges Propagation in the Corticolimbic Basal Ganglia System during Amygdala Kindled Seizures in Freely Moving Rats  

PubMed Central

We used a multiple channel, single unit recording technique to investigate the neural activity in different corticolimbic and basal ganglia regions in freely moving rats before and during generalized amygdala kindled seizures. Neural activity was recorded simultaneously in the sensorimotor cortex (Ctx), hippocampus, amygdala, substantia nigra pars reticulata (SNr) and the subthalamic nucleus (STN). We observed massive synchronized activity among neurons of different brain regions during seizure episodes. Neurons in the kindled amygdala led other regions in synchronized firing, revealed by time lags of neurons in other regions in crosscorrelogram analysis. While there was no obvious time lag between Ctx and SNr, the STN and hippocampus did lag behind the Ctx and SNr in correlated firing. Activity in the amygdala and SNr contralateral to the kindling stimulation site lagged behind their ipsilateral counterparts. However no time lag was found between the kindling and contralateral sides of Ctx, hippocampus and STN. Our data confirm that the amygdala is an epileptic focus that emits ictal discharges to other brain regions. The observed temporal pattern indicates that ictal discharges from the amygdala arrive first at Ctx and SNr, and then spread to the hippocampus and STN. The simultaneous activation of both sides of the Ctx suggests that the neocortex participates in kindled seizures as a unisonant entity to provoke the clonic motor seizures. Early activation of the SNr (before the STN and hippocampus) points to an important role of the SNr in amygdala kindled seizures and supports the view that different SNr manipulations may be effective ways to control seizures. PMID:17049434

Shi, Li-Hong; Luo, Fei; Woodward, Donald J.; McIntyre, Dan C.; Chang, Jing-Yu

2007-01-01

213

Striatal dopamine ramping may indicate flexible reinforcement learning with forgetting in the cortico-basal ganglia circuits  

PubMed Central

It has been suggested that the midbrain dopamine (DA) neurons, receiving inputs from the cortico-basal ganglia (CBG) circuits and the brainstem, compute reward prediction error (RPE), the difference between reward obtained or expected to be obtained and reward that had been expected to be obtained. These reward expectations are suggested to be stored in the CBG synapses and updated according to RPE through synaptic plasticity, which is induced by released DA. These together constitute the DA=RPE hypothesis, which describes the mutual interaction between DA and the CBG circuits and serves as the primary working hypothesis in studying reward learning and value-based decision-making. However, recent work has revealed a new type of DA signal that appears not to represent RPE. Specifically, it has been found in a reward-associated maze task that striatal DA concentration primarily shows a gradual increase toward the goal. We explored whether such ramping DA could be explained by extending the DA=RPE hypothesis by taking into account biological properties of the CBG circuits. In particular, we examined effects of possible time-dependent decay of DA-dependent plastic changes of synaptic strengths by incorporating decay of learned values into the RPE-based reinforcement learning model and simulating reward learning tasks. We then found that incorporation of such a decay dramatically changes the model's behavior, causing gradual ramping of RPE. Moreover, we further incorporated magnitude-dependence of the rate of decay, which could potentially be in accord with some past observations, and found that near-sigmoidal ramping of RPE, resembling the observed DA ramping, could then occur. Given that synaptic decay can be useful for flexibly reversing and updating the learned reward associations, especially in case the baseline DA is low and encoding of negative RPE by DA is limited, the observed DA ramping would be indicative of the operation of such flexible reward learning. PMID:24782717

Morita, Kenji; Kato, Ayaka

2014-01-01

214

Singing-related neural activity distinguishes two putative pallidal cell types in the songbird basal ganglia: comparison to the primate internal and external pallidal segments  

PubMed Central

The songbird area X is a basal ganglia homologue that contains two pallidal cell typeslocal neurons that project within the basal ganglia and output neurons that project to the thalamus. Based on these projections, it has been proposed that these classes are structurally homologous to the primate external (GPe) and internal (GPi) pallidal segments. To test the hypothesis that the two area X pallidal types are functionally homologous to GPe and GPi neurons, we recorded from neurons in area X of singing juvenile male zebra finches, and directly compare their firing patterns to neurons recorded in the primate pallidus. In area X, we find two cell classes that exhibited high firing (HF) rates (>60Hz) characteristic of pallidal neurons. HF-1 neurons, like most GPe neurons we examined, exhibited large firing rate modulations, including bursts and long pauses. In contrast, HF-2 neurons, like GPi neurons, discharged continuously without bursts or long pauses. To test if HF-2 neurons were the output neurons that project to the thalamus, we next recorded directly from pallidal axon terminals in thalamic nucleus DLM, and found that all terminals exhibited singing-related firing patterns indistinguishable from HF-2 neurons. Our data show that singing-related neural activity distinguishes two putative pallidal cell types in area X: thalamus-projecting neurons that exhibit activity similar to the primate GPi, and non-thalamus-projecting neurons that exhibit activity similar to the primate GPe. These results suggest that song learning in birds and motor learning in mammals employ conserved basal ganglia signaling strategies. PMID:20484651

Goldberg, Jesse H.; Adler, Avital; Bergman, Hagai; Fee, Michale S.

2010-01-01

215

Signal enhancement in the output stage of the basal ganglia by synaptic short-term plasticity in the direct, indirect, and hyperdirect pathways  

PubMed Central

Many of the synapses in the basal ganglia display short-term plasticity. Still, computational models have not yet been used to investigate how this affects signaling. Here we use a model of the basal ganglia network, constrained by available data, to quantitatively investigate how synaptic short-term plasticity affects the substantia nigra reticulata (SNr), the basal ganglia output nucleus. We find that SNr becomes particularly responsive to the characteristic burst-like activity seen in both direct and indirect pathway striatal medium spiny neurons (MSN). As expected by the standard model, direct pathway MSNs are responsible for decreasing the activity in SNr. In particular, our simulations indicate that bursting in only a few percent of the direct pathway MSNs is sufficient for completely inhibiting SNr neuron activity. The standard model also suggests that SNr activity in the indirect pathway is controlled by MSNs disinhibiting the subthalamic nucleus (STN) via the globus pallidus externa (GPe). Our model rather indicates that SNr activity is controlled by the direct GPe-SNr projections. This is partly because GPe strongly inhibits SNr but also due to depressing STN-SNr synapses. Furthermore, depressing GPe-SNr synapses allow the system to become sensitive to irregularly firing GPe subpopulations, as seen in dopamine depleted conditions, even when the GPe mean firing rate does not change. Similar to the direct pathway, simulations indicate that only a few percent of bursting indirect pathway MSNs can significantly increase the activity in SNr. Finally, the model predicts depressing STN-SNr synapses, since such an assumption explains experiments showing that a brief transient activation of the hyperdirect pathway generates a tri-phasic response in SNr, while a sustained STN activation has minor effects. This can be explained if STN-SNr synapses are depressing such that their effects are counteracted by the (known) depressing GPe-SNr inputs. PMID:23801960

Lindahl, Mikael; Kamali Sarvestani, Iman; Ekeberg, Orjan; Kotaleski, Jeanette Hellgren

2013-01-01

216

Gait variability and basal ganglia disorders: stride-to-stride variations of gait cycle timing in Parkinson's disease and Huntington's disease  

NASA Technical Reports Server (NTRS)

The basal ganglia are thought to play an important role in regulating motor programs involved in gait and in the fluidity and sequencing of movement. We postulated that the ability to maintain a steady gait, with low stride-to-stride variability of gait cycle timing and its subphases, would be diminished with both Parkinson's disease (PD) and Huntington's disease (HD). To test this hypothesis, we obtained quantitative measures of stride-to-stride variability of gait cycle timing in subjects with PD (n = 15), HD (n = 20), and disease-free controls (n = 16). All measures of gait variability were significantly increased in PD and HD. In subjects with PD and HD, gait variability measures were two and three times that observed in control subjects, respectively. The degree of gait variability correlated with disease severity. In contrast, gait speed was significantly lower in PD, but not in HD, and average gait cycle duration and the time spent in many subphases of the gait cycle were similar in control subjects, HD subjects, and PD subjects. These findings are consistent with a differential control of gait variability, speed, and average gait cycle timing that may have implications for understanding the role of the basal ganglia in locomotor control and for quantitatively assessing gait in clinical settings.

Hausdorff, J. M.; Cudkowicz, M. E.; Firtion, R.; Wei, J. Y.; Goldberger, A. L.

1998-01-01

217

The role of dopamine-dependent negative feedback in the hippocampus-basal ganglia-thalamus-hippocampus loop in the extinction of responses.  

PubMed

A mechanism for the extinction of the responses of hippocampal and dopaminergic neurons to repeated sensory stimuli is proposed, based on dopamine-dependent negative feedback in the hippocampus-basal ganglia-thalamus-hippocampus loop. Activation of hippocampal neurons evoked by a new stimulus facilitates the appearance of responses in dopaminergic neurons as a result of disinhibition via striopallidal cells of the nucleus accumbens and ventral pallidum. However, increases in dopamine levels and activation of D2 receptors on striopallidal cells, facilitating depression of hippocampal inputs, prevent disinhibition of dopaminergic neurons, such that their responses start to decline. Subsequent reductions in actions on D1 receptors lead to decreases in the efficiency of excitation both of neurons in hippocampal field CA1 and strionigral cells in the nucleus accumbens. The direct pathway via the basal ganglia mediates disinhibition of the thalamic nucleus reuniens, exciting neurons in field CA1, which leads to extinction of the responses of hippocampal neurons, decreases in disinhibition of dopaminergic cells, and further extinction of their responses. PMID:18401733

Sil'kis, I G

2008-05-01

218

Total number of neurons in the neostriatal, pallidal, subthalamic, and substantia nigral nuclei of the rat basal ganglia: a stereological study using the cavalieri and optical disector methods.  

PubMed

The total number of neurons within six subdivisions of the rat basal ganglia was estimated using unbiased stereological counting methods and systematic random sampling techniques. Six young adult rats were perfuse-fixed, their right cerebral hemispheres were embedded in glycolmethacrylate, and a complete set of serial 40-mu m sections was cut through each hemisphere. After a random start, a systematic subset (e.g., every tenth) of these sections was used to estimate the total volume of each subdivision using Cavalieri's method. The same set of sampled sections was used to estimate the number of neurons in a known subvolume (i.e., the Nv) by the optical disector method. The product of the total volume and the Nv by these methods yields an unbiased estimate of the total number of neurons. It was found that the right basal ganglia consisted, on average, of 2.79 million neostriatal or caudate-putamen neurons (with a coefficient of variation of 0.07), 46,000 external globus pallidus neurons (0.11), 3,200 entopeduncular/internal globus pallidus neurons (0.10), 13,600 subthalamic neurons (0.10), 7,200 substantial nigra pars compacta neurons (0.15), and 26,300 substantia nigra pars reticulata neurons (0.07). PMID:8833111

Oorschot, D E

1996-03-18

219

Downregulation of cannabinoid receptor 1 from neuropeptide Y interneurons in the basal ganglia of patients with Huntington's disease and mouse models  

PubMed Central

Cannabinoid receptor 1 (CB1 receptor) controls several neuronal functions, including neurotransmitter release, synaptic plasticity, gene expression and neuronal viability. Downregulation of CB1 expression in the basal ganglia of patients with Huntingtons disease (HD) and animal models represents one of the earliest molecular events induced by mutant huntingtin (mHtt). This early disruption of neuronal CB1 signaling is thought to contribute to HD symptoms and neurodegeneration. Here we determined whether CB1 downregulation measured in patients with HD and mouse models was ubiquitous or restricted to specific striatal neuronal subpopulations. Using unbiased semi-quantitative immunohistochemistry, we confirmed previous studies showing that CB1 expression is downregulated in medium spiny neurons of the indirect pathway, and found that CB1 is also downregulated in neuropeptide Y (NPY)/neuronal nitric oxide synthase (nNOS)-expressing interneurons while remaining unchanged in parvalbumin- and calretinin-expressing interneurons. CB1 downregulation in striatal NPY/nNOS-expressing interneurons occurs in R6/2 mice, HdhQ150/Q150 mice and the caudate nucleus of patients with HD. In R6/2 mice, CB1 downregulation in NPY/nNOS-expressing interneurons correlates with diffuse expression of mHtt in the soma. This downregulation also occludes the ability of cannabinoid agonists to activate the pro-survival signaling molecule cAMP response element-binding protein in NPY/nNOS-expressing interneurons. Loss of CB1 signaling in NPY/nNOS-expressing interneurons could contribute to the impairment of basal ganglia functions linked to HD. PMID:23167744

Horne, Eric A.; Coy, Jonathan; Swinney, Katie; Fung, Susan; Cherry, Allison E. T.; Marrs, William R.; Naydenov, Alipi V.; Lin, Yi Hsing; Sun, Xiaocui; Keene, C. Dirk; Grouzmann, Eric; Muchowski, Paul; Bates, Gillian P.; Mackie, Ken; Stella, Nephi

2013-01-01

220

Comparing the neural correlates of affective and cognitive theory of mind using fMRI: Involvement of the basal ganglia in affective theory of mind  

PubMed Central

Theory of Mind (ToM) is the ability to infer other peoples mental states like intentions or desires. ToM can be differentiated into affective (i.e., recognizing the feelings of another person) and cognitive (i.e., inferring the mental state of the counterpart) subcomponents. Recently, subcortical structures such as the basal ganglia (BG) have also been ascribed to the multifaceted concept ToM and most BG disorders have been reported to elicit ToM deficits. In order to assess both the correlates of affective and cognitive ToM as well as involvement of the basal ganglia, 30 healthy participants underwent event-related fMRI scanning, neuropsychological testing, and filled in questionnaires concerning different aspects of ToM and empathy. Directly contrasting affective (aff) as well as cognitive (cog) ToM to the control (phy) condition, activation was found in classical ToM regions, namely parts of the temporal lobe including the superior temporal sulcus, the supplementary motor area, and parietal structures in the right hemisphere. The contrast aff > phy yielded additional activation in the orbitofrontal cortex on the right and the cingulate cortex, the precentral and inferior frontal gyrus and the cerebellum on the left. The right BG were recruited in this contrast as well. The direct contrast aff > cog showed activation in the temporoparietal junction and the cingulate cortex on the right as well as in the left supplementary motor area. The reverse contrast cog > aff however did not yield any significant clusters. In summary, affective and cognitive ToM partly share neural correlates but can also be differentiated anatomically. Furthermore, the BG are involved in affective ToM and thus their contribution is discussed as possibly providing a motor component of simulation processes, particularly in affective ToM. PMID:23853676

Bodden, Maren E.; Kubler, Dorothee; Knake, Susanne; Menzler, Katja; Heverhagen, Johannes T.; Sommer, Jens; Kalbe, Elke; Krach, Soren; Dodel, Richard

2013-01-01

221

Differential gene expression for glutamic acid decarboxylase and type II calcium-calmodulin-dependent protein kinase in basal ganglia, thalamus, and hypothalamus of the monkey  

SciTech Connect

In situ hybridization histochemistry, using cRNA probes, revealed a complementarity in the distributions of cells in the basal ganglia, basal nucleus of Meynert, thalamus, hypothalamus, and rostral part of the midbrain that showed gene expression for glutamic acid decarboxylase (GAD) or the alpha-subunit of type II calcium-calmodulin-dependent protein kinase (CAM II kinase-alpha). Cells in certain nuclei such as the thalamic reticular nucleus, globus pallidus, and pars reticulata of the substantia nigra show GAD gene expression only; others in nuclei such as the basal nucleus of Meynert, medial mamillary nuclei, and ventromedial hypothalamic nuclei show CAM II kinase-alpha gene expression only. A few nuclei, for example, the pars compacta of the substantia nigra and the greater part of the subthalamic nucleus, display gene expression for neither GAD nor CAM II kinase-alpha. In other nuclei, notably those of the dorsal thalamus, and possibly in the striatum, GAD- and CAM II kinase-expressing cells appear to form two separate populations that, in most thalamic nuclei, together account for the total cell population. In situ hybridization reveals large amounts of CAM II kinase-alpha mRNA in the neuropil of most nuclei containing CAM II kinase-alpha-positive cells, suggesting its association with dendritic polyribosomes. The message may thus be translated at those sites, close to the synapses with which the protein is associated. The in situ hybridization results, coupled with those from immunocytochemical staining for CAM II kinase-alpha protein, indicate that CAM II kinase-alpha is commonly found in certain non-GABAergic afferent fiber systems but is not necessarily present in the postsynaptic cells on which they terminate. It appears to be absent from most GABAergic fiber systems but can be present in the cells on which they terminate.

Benson, D.L.; Isackson, P.J.; Hendry, S.H.; Jones, E.G. (Department of Anatomy, University of California, Irvine (USA))

1991-06-01

222

An extended reinforcement learning model of basal ganglia to understand the contributions of serotonin and dopamine in risk-based decision making, reward prediction, and punishment learning  

PubMed Central

Although empirical and neural studies show that serotonin (5HT) plays many functional roles in the brain, prior computational models mostly focus on its role in behavioral inhibition. In this study, we present a model of risk based decision making in a modified Reinforcement Learning (RL)-framework. The model depicts the roles of dopamine (DA) and serotonin (5HT) in Basal Ganglia (BG). In this model, the DA signal is represented by the temporal difference error (?), while the 5HT signal is represented by a parameter (?) that controls risk prediction error. This formulation that accommodates both 5HT and DA reconciles some of the diverse roles of 5HT particularly in connection with the BG system. We apply the model to different experimental paradigms used to study the role of 5HT: (1) Risk-sensitive decision making, where 5HT controls risk assessment, (2) Temporal reward prediction, where 5HT controls time-scale of reward prediction, and (3) Reward/Punishment sensitivity, in which the punishment prediction error depends on 5HT levels. Thus the proposed integrated RL model reconciles several existing theories of 5HT and DA in the BG. PMID:24795614

Balasubramani, Pragathi P.; Chakravarthy, V. Srinivasa; Ravindran, Balaraman; Moustafa, Ahmed A.

2014-01-01

223

Seasonal change in neuron size and spacing but not neuronal recruitment in a basal ganglia nucleus in the avian song control system.  

PubMed

Neural plasticity in the song control system of seasonally breeding songbirds accompanies seasonal changes in singing behavior. The volume of Area X, a song control nucleus that forms a portion of the avian basal ganglia, is 75% larger in the spring than it is in the fall. The neuronal basis of the seasonal plasticity in Area X is largely unknown, however. We examined neuronal attributes of Area X in wild adult male song sparrows (Melospiza melodia) captured during the spring and the fall after being implanted for 30 days with osmotic pumps containing [3H]thymidine. We measured the volume of Area X from thionin-stained sections, and neuronal density and number, and average area of the soma from sections labeled with an antibody against Hu, a neuron-specific protein. We sampled two neuron classes: "small" neurons that were most likely striatal-like spiny neurons and "large" neurons, which most likely included pallidal-like projection neurons. We also analyzed seasonal patterns of neuronal recruitment to Area X. The average area of the soma and neuronal spacing for both neuronal classes were greater in breeding birds. There was no difference in total neuron number for both neuronal classes between seasons. The average area of the soma and density and number of newly recruited neurons did not vary across seasons. These results demonstrate that seasonal plasticity in Area X includes changes in neuron size and neuronal density, but not changes in the rate at which new neurons are recruited. PMID:15593375

Thompson, Christopher K; Brenowitz, Eliot A

2005-01-17

224

In vivo metabolite differences between the basal ganglia and cerebellum of the rat brain detected with proton MRS at 3T  

PubMed Central

In vivo magnetic resonance spectroscopy (MRS) enables non-invasive longitudinal tracking of brain chemistry changes that can accompany aging, neurodegenerative disease, drug addiction and experimental manipulations in animals modeling such conditions. J-coupled resonances, such as glutamate, which are highly relevant to neuropsychiatric conditions are difficult to resolve on a clinical 3T MR scanner using conventional one-dimensional MRS sequences. We, therefore, implemented Constant Time PRESS (CT-PRESS) to quantify major metabolite and neurotransmitter biochemical signals, including glutamate, in two brain regions of the ratbasal ganglia and cerebellum. We acquired spectra at two distinct time points in two independent groups of six rats and analyzed metabolite levels using either creatine or water as a reference. Our results provide evidence that CT-PRESS at 3T is adequate and reliable for in vivo detection and quantification of glutamate in the rat brain and that regional differences occur in the signal intensities of the major metabolites. That the directionality of the differences depends on whether creatine or water is used as a reference for metabolite levels emphasizes the benefit to in vivo MRS of incorporating methods to establish absolute baseline metabolite concentrations. PMID:17346948

Zahr, Natalie M.; Sullivan, Edith V.; Pfefferbaum, Adolf

2007-01-01

225

Basal ganglia neural responses during behaviorally effective deep brain stimulation of the subthalamic nucleus in rats performing a treadmill locomotion test.  

PubMed

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for Parkinson's disease (PD). In spite of proven therapeutic success, the mechanism underlying the benefits of DBS has not been resolved. A multiple-channel single-unit recording technique was used in the present study to investigate basal ganglia (BG) neural responses during behaviorally effective DBS of the STN in a rat model of PD. Rats underwent unilateral dopamine (DA) depletion by injection of 6-hydroxyDA (6-OHDA) into one side of the medial forebrain bundle and subsequently developed a partial akinesia, which was assessed during the treadmill locomotion task. High frequency stimulation (HFS) of the STN restored normal treadmill locomotion behavior. Simultaneous recording of single unit activity in the striatum (STR), globus pallidus (GP), substantia nigra pars reticulata (SNr), and STN revealed a variety of neural responses during behaviorally effective HFS of the STN. Predominant inhibitory responses appeared in the STN stimulation site. Nearly equal numbers of excitatory and inhibitory responses were found in the GP and SNr, whereas more rebound excitatory responses were found in the STR. Mean firing rate did not change significantly in the STR, GP, and SNr, but significantly decreased in both sides of STN during DBS. A decrease in firing rate in the contralateral side of STN provides neural substrate for the clinical observation that unilateral DBS produces bilateral benefits in patients with PD. In addition to the firing rate changes, a decrease in burst firing was observed in the GP and STN. The present study indicates that DBS induces complex modulations of the BG circuit and further suggests that BG network reorganization, rather than a simple excitation or inhibition, may underlie the therapeutic effects of DBS in patients with PD. PMID:16521122

Shi, Li-Hong; Luo, Fei; Woodward, Donald J; Chang, Jing-Yu

2006-06-01

226

Characterization and distribution of (125I)epidepride binding to dopamine D2 receptors in basal ganglia and cortex of human brain  

SciTech Connect

The distribution and pharmacology of the binding of {sup 125}I-epidepride, a substituted benzamide with high affinity and selectivity for dopamine (DA) D2 receptors in rat brain is described in human brain. Saturation analysis of the binding of {sup 125}I-epidepride to membranes derived from striatum and regions of cortex demonstrated similar Kd values (34 and 28-33 pM, respectively) but differing maximum density of binding site values (152 and 3-8 fmol/mg of protein, respectively). The pharmacological profile of binding in cortex was also similar to striatum (epidepride greater than spiperone greater than butaclamol = flupenthixol greater than clozapine) except that an additional low-affinity site, blocked by the alpha-2 adrenergic antagonist idazoxan, was present in cortex. Quantification by autoradiography also demonstrated the greatest binding in the basal ganglia, with the striatum exhibiting greater binding than the pallidal complex or midbrain regions. For the pallidum, binding in the external segment was higher than the internal segment. Within the midbrain the binding of {sup 125}I-epidepride correlated well with the known distribution of DA-containing cell bodies, with the substantia nigra (pars compacta and pars lateralis) and ventral tegmental area (A10) higher than area A8 and central gray. Binding in frontal and parietal cortex was highest in the internal layers (layers V and VI). Temporal cortex showed a 2-fold higher density of binding than other cortical regions and a trilaminar pattern; binding was greater in the external (layers I and II) and internal layers than in the middle layers (III and IV). This pattern changed in the parahippocampal complex. Within the lateral occipitotemporal cortex, binding was densest in layers I to III and very low in layers IV to VI, but binding was almost nonexistent in the adjacent entorhinal cortex.

Joyce, J.N.; Janowsky, A.; Neve, K.A. (Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia (USA))

1991-06-01

227

c-Fos immunoreactivity in prefrontal, basal ganglia and limbic areas of the rat brain after central and peripheral administration of ethanol and its metabolite acetaldehyde  

PubMed Central

Considerable evidence indicates that the metabolite of ethanol (EtOH), acetaldehyde, is biologically active. Acetaldehyde can be formed from EtOH peripherally mainly by alcohol dehydrogenase (ADH), and also centrally by catalase. EtOH and acetaldehyde show differences in their behavioral effects depending upon the route of administration. In terms of their effects on motor activity and motivated behaviors, when administered peripherally acetaldehyde tends to be more potent than EtOH but shows very similar potency administered centrally. Since dopamine (DA) rich areas have an important role in regulating both motor activity and motivation, the present studies were undertaken to compare the effects of central (intraventricular, ICV) and peripheral (intraperitoneal, IP) administration of EtOH and acetaldehyde on a cellular marker of brain activity, c-Fos immunoreactivity, in DA innervated areas. Male Sprague-Dawley rats received an IP injection of vehicle, EtOH (0.5 or 2.5 g/kg) or acetaldehyde (0.1 or 0.5 g/kg) or an ICV injection of vehicle, EtOH or acetaldehyde (2.8 or 14.0 ?moles). IP administration of EtOH minimally induced c-Fos in some regions of the prefrontal cortex and basal ganglia, mainly at the low dose (0.5 g/kg), while IP acetaldehyde induced c-Fos in virtually all the structures studied at both doses. Acetaldehyde administered centrally increased c-Fos in all areas studied, a pattern that was very similar to EtOH. Thus, IP administered acetaldehyde was more efficacious than EtOH at inducing c-Fos expression. However, the general pattern of c-Fos induction promoted by ICV EtOH and acetaldehyde was similar. These results are consistent with the pattern observed in behavioral studies in which both substances produced the same magnitude of effect when injected centrally, and produced differences in potency after peripheral administration. PMID:23745109

Segovia, Kristen N.; Vontell, Regina; Lpez-Cruz, Laura; Salamone, John D.; Correa, Merc

2013-01-01

228

High-frequency stimulation of the subthalamic nucleus modifies the expression of vesicular glutamate transporters in basal ganglia in a rat model of Parkinson's disease  

PubMed Central

Background It has been suggested that glutamatergic system hyperactivity may be related to the pathogenesis of Parkinsons disease (PD). Vesicular glutamate transporters (VGLUT1-3) import glutamate into synaptic vesicles and are key anatomical and functional markers of glutamatergic excitatory transmission. Both VGLUT1 and VGLUT2 have been identified as definitive markers of glutamatergic neurons, but VGLUT 3 is also expressed by non glutamatergic neurons. VGLUT1 and VGLUT2 are thought to be expressed in a complementary manner in the cortex and the thalamus (VL/VM), in glutamatergic neurons involved in different physiological functions. Chronic high-frequency stimulation (HFS) of the subthalamic nucleus (STN) is the neurosurgical therapy of choice for the management of motor deficits in patients with advanced PD. STN-HFS is highly effective, but its mechanisms of action remain unclear. This study examines the effect of STN-HFS on VGLUT1-3 expression in different brain nuclei involved in motor circuits, namely the basal ganglia (BG) network, in normal and 6-hydroxydopamine (6-OHDA) lesioned rats. Results Here we report that: 1) Dopamine(DA)-depletion did not affect VGLUT1 and VGLUT3 expression but significantly decreased that of VGLUT2 in almost all BG structures studied; 2) STN-HFS did not change VGLUT1-3 expression in the different brain areas of normal rats while, on the contrary, it systematically induced a significant increase of their expression in DA-depleted rats and 3) STN-HFS reversed the decrease in VGLUT2 expression induced by the DA-depletion. Conclusions These results show for the first time a comparative analysis of changes of expression for the three VGLUTs induced by STN-HFS in the BG network of normal and hemiparkinsonian rats. They provide evidence for the involvement of VGLUT2 in the modulation of BG cicuits and in particular that of thalamostriatal and thalamocortical pathways suggesting their key role in its therapeutic effects for alleviating PD motor symptoms. PMID:24308494

2013-01-01

229

Eyeblink Conditioning Deficits Indicate Timing and Cerebellar Abnormalities in Schizophrenia  

ERIC Educational Resources Information Center

Accumulating evidence indicates that individuals with schizophrenia manifest abnormalities in structures (cerebellum and basal ganglia) and neurotransmitter systems (dopamine) linked to internal-timing processes. A single-cue tone delay eyeblink conditioning paradigm comprised of 100 learning and 50 extinction trials was used to examine cerebellar

Brown, S.M.; Kieffaber, P.D.; Carroll, C.A.; Vohs, J.L.; Tracy, J.A.; Shekhar, A.; O'Donnell, B.F.; Steinmetz, J.E.; Hetrick, W.P.

2005-01-01

230

The Albin-DeLong `box and arrow' model has long been the accepted standard model for the basal ganglia network.  

E-print Network

689 The Albin-DeLong `box and arrow' model has long been the accepted standard model for the basal is bound by the underlying anatomical substrate. One of the first modern models (the Albin-DeLong model [5 thalamo­cortical networks (Figure 1a). The Albin-DeLong model assumes two segregated feed- forward

Bar-Gad, Izhar

231

Abnormal Cerebral Activation Associated with a Motor Task in Tourette Syndrome  

Microsoft Academic Search

BACKGROUND AND PURPOSE: In Gilles de la Tourette syndrome, PET scanning and EEG suggest an abnormal organization of the sensorimotor cortex and basal ganglia. The purpose of this study was to use functional MR imaging to study activation in the sensorimotor cortex in patients with Tourette syndrome. METHODS: From echo-planar images acquired during intermittent performance of a finger- tapping task,

Bharat Biswal; John L. Ulmer; Robert L. Krippendorf; Harold H. Harsch; David L. Daniels; James S. Hyde; Victor M. Haughton

232

Cortico-Basal Ganglia Reward Network: Microcircuitry  

Microsoft Academic Search

Many of the brain's reward systems converge on the nucleus accumbens, a region richly innervated by excitatory, inhibitory, and modulatory afferents representing the circuitry necessary for selecting adaptive motivated behaviors. The ventral subiculum of the hippocampus provides contextual and spatial information, the basolateral amygdala conveys affective influence, and the prefrontal cortex provides an integrative impact on goal-directed behavior. The balance

Susan R Sesack; Anthony A Grace; AA Grace

2010-01-01

233

Convergent evidence for abnormal striatal synaptic plasticity in dystonia  

PubMed Central

Dystonia is a functionally disabling movement disorder characterized by abnormal movements and postures. Although substantial recent progress has been made in identifying genetic factors, the pathophysiology of the disease remains a mystery. A provocative suggestion gaining broader acceptance is that some aspect of neural plasticity may be abnormal. There is also evidence that, at least in some forms of dystonia, sensorimotor use may be a contributing factor. Most empirical evidence of abnormal plasticity in dystonia comes from measures of sensorimotor cortical organization and physiology. However, the basal ganglia also play a critical role in sensorimotor function. Furthermore, the basal ganglia are prominently implicated in traditional models of dystonia, are the primary targets of stereotactic neurosurgical interventions, and provide a neural substrate for sensorimotor learning influenced by neuromodulators. Our working hypothesis is that abnormal plasticity in the basal ganglia is a critical link between the etiology and pathophysiology of dystonia. In this review we set up the background for this hypothesis by integrating a large body of disparate indirect evidence that dystonia may involve abnormalities in synaptic plasticity in the striatum. After reviewing evidence implicating the striatum in dystonia, we focus on the influence of two neuromodulatory systems: dopamine and acetylcholine. For both of these neuromodulators, we first describe the evidence for abnormalities in dystonia and then the means by which it may influence striatal synaptic plasticity. Collectively, the evidence suggests that many different forms of dystonia may involve abnormal plasticity in the striatum. An improved understanding of these altered plastic processes would help inform our understanding of the pathophysiology of dystonia, and, given the role of the striatum in sensorimotor learning, provide a principled basis for designing therapies aimed at the dynamic processes linking etiology to pathophysiology of the disease. PMID:20005952

Peterson, David A.; Sejnowski, Terrence J.; Poizner, Howard

2010-01-01

234

Basal bioenergetic abnormalities in skeletal muscle from ryanodine receptor malignant hyperthermia-susceptible R163C knock-in mice.  

PubMed

Malignant hyperthermia (MH) and central core disease in humans have been associated with mutations in the skeletal ryanodine receptor (RyR1). Heterozygous mice expressing the human MH/central core disease RyR1 R163C mutation exhibit MH when exposed to halothane or heat stress. Considering that many MH symptoms resemble those that could ensue from a mitochondrial dysfunction (e.g. metabolic acidosis and hyperthermia) and that MH-susceptible mice or humans have a higher than normal cytoplasmic Ca(2+) concentration at rest, we evaluated the role of mitochondria in skeletal muscle from R163C compared with wild type mice under basal (untriggered) conditions. R163C skeletal muscle exhibited a significant increase in matrix Ca(2+), increased reactive oxygen species production, lower expression of mitochondrial proteins, and higher mtDNA copy number. These changes, in conjunction with lower myoglobin and glycogen contents, Myh4 and GAPDH transcript levels, GAPDH activity, and lower glucose utilization suggested a switch to a compromised bioenergetic state characterized by both low oxidative phosphorylation and glycolysis. The shift in bioenergetic state was accompanied by a dysregulation of Ca(2+)-responsive signaling pathways regulated by calcineurin and ERK1/2. Chronically elevated resting Ca(2+) in R163C skeletal muscle elicited the maintenance of a fast-twitch fiber program and the development of insulin resistance-like phenotype as part of a metabolic adaptation to the R163C RyR1 mutation. PMID:20978128

Giulivi, Cecilia; Ross-Inta, Catherine; Omanska-Klusek, Alicja; Napoli, Eleonora; Sakaguchi, Danielle; Barrientos, Genaro; Allen, Paul D; Pessah, Isaac N

2011-01-01

235

Use of a novel high-resolution magnetic resonance neurography protocol to detect abnormal dorsal root Ganglia in Sjgren patients with neuropathic pain: case series of 10 patients and review of the literature.  

PubMed

The diagnosis and treatment of patients with Sjgren syndrome (SS) with neuropathic pain pose several challenges. Patients with SS may experience unorthodox patterns of burning pain not conforming to a traditional "stocking-and-glove" distribution, which can affect the face, torso, and proximal extremities. This distribution of neuropathic pain may reflect mechanisms targeting the proximal-most element of the peripheral nervous system-the dorsal root ganglia (DRG). Skin biopsy can diagnose such a small-fiber neuropathy and is a surrogate marker of DRG neuronal cell loss. However, SS patients have been reported who have similar patterns of proximal neuropathic pain, despite having normal skin biopsy studies. In such cases, DRGs may be targeted by mechanisms not associated with neuronal cell loss. Therefore, alternative approaches are warranted to help characterize abnormal DRGs in SS patients with proximal neuropathic pain.We performed a systematic review of the literature to define the frequency and spectrum of SS peripheral neuropathies, and to better understand the attribution of SS neuropathic pain to peripheral neuropathies. We found that the frequency of SS neuropathic pain exceeded the prevalence of peripheral neuropathies, and that painful peripheral neuropathies occurred less frequently than neuropathies not always associated with pain. We developed a novel magnetic resonance neurography (MRN) protocol to evaluate DRG abnormalities. Ten SS patients with proximal neuropathic pain were evaluated by this MRN protocol, as well as by punch skin biopsies evaluating for intraepidermal nerve fiber density (IENFD) of unmyelinated nerves. Five patients had radiographic evidence of DRG abnormalities. Patients with MRN DRG abnormalities had increased IENFD of unmyelinated nerves compared to patients without MRN DRG abnormalities (30.2 [interquartile range, 4.4] fibers/mm vs. 11.0 [4.1] fibers/mm, respectively; p = 0.03). Two of these 5 SS patients whose neuropathic pain resolved with intravenous immunoglobulin (IVIg) therapy had improvement of MRN DRG abnormalities.We have developed a novel MRN protocol that can detect DRG abnormalities in SS patients with neuropathic pain who do not have markers of peripheral neuropathy. We found that SS patients with MRN DRG abnormalities had statistically significant, increased IENFD on skin biopsy studies, which may suggest a relationship between trophic mediators and neuropathic pain. Given that our literature review has demonstrated that many SS neuropathic pain patients do not have a neuropathy, our findings suggest an important niche for this MRN DRG technique in the evaluation of broader subsets of SS neuropathic pain patients who may not have underlying neuropathies. The improvement of MRN DRG abnormalities in patients with IVIg-induced remission of neuropathic pain suggests that our MRN protocol may be capturing reversible, immune-mediated mechanisms targeting the DRG. PMID:24797167

Birnbaum, Julius; Duncan, Trisha; Owoyemi, Kristie; Wang, Kenneth C; Carrino, John; Chhabra, Avneesh

2014-05-01

236

What are the Computations of the Cerebellum, the Basal Gangila, and the Cerebral Cortex?  

E-print Network

What are the Computations of the Cerebellum, the Basal Gangila, and the Cerebral Cortex? Kenji Doya to characterize the functions of the cerebellum, the basal ganglia and the cerebral cortex in a simplistic manner learning, the basal ganglia are for reinforcement learning, and the cerebral cortex is for unsupervised

Doya, Kenji

237

Skeletal limb abnormalities  

MedlinePLUS

Skeletal limb abnormalities may be due to: Cancer Genetic diseases and chromosomal abnormalities, including Marfan syndrome , Down syndrome, Apert syndrome , Basal cell nevus syndrome Improper position in the womb Infections during pregnancy ...

238

Bilateral lunate intraosseous ganglia.  

PubMed

An intraosseous ganglion is a relatively uncommon, benign cystic lesion that occurs in young and middle-aged adults. Bilateral and symmetrical lesions of the wrist are rare. Intraosseous ganglia of the carpal bones are uncommon causes of chronic wrist pain. Isolated cases of intraosseous ganglion have been reported most commonly in the lunate and scaphoid. The lunate was most frequently affected, followed by the capitate, scaphoid, and triquetrum bones. Radiolucent lesions in the carpal bones are not uncommon and are often seen incidentally in asymptomatic patients. The differential diagnosis of a lytic lesion in a carpal bone includes unicameral bone cyst, degenerative cyst, fibrous developmental defect, osteomyelitis, and intraosseous ganglion cyst. This article describes a case of bilateral lunate intraosseous ganglia. A review of the literature revealed that bilateral and symmetrical intraosseous ganglia of the wrist are rare, with only 3 other reported cases of bilateral lunate lesions. PMID:20608626

Kural, Cemal; Sungur, Ibrahim; Cetinus, Ercan

2010-07-01

239

An engineering model of lower thalamo-cortico-basal ganglionic circuit function  

E-print Network

An engineering model of lower thalamo-cortico-basal ganglionic circuit functionality was extended and tested. This model attempts to explain the circuitry of the basal ganglia, examine its functional properties, and integrate ...

Lim, Eugene J. (Eugene Jungsud), 1980-

2003-01-01

240

Motor Control Abnormalities in Parkinson's Disease  

PubMed Central

The primary manifestations of Parkinsons disease are abnormalities of movement, including movement slowness, difficulties with gait and balance, and tremor. We know a considerable amount about the abnormalities of neuronal and muscle activity that correlate with these symptoms. Motor symptoms can also be described in terms of motor control, a level of description that explains how movement variables, such as a limbs position and speed, are controlled and coordinated. Understanding motor symptoms as motor control abnormalities means to identify how the disease disrupts normal control processes. In the case of Parkinsons disease, movement slowness, for example, would be explained by a disruption of the control processes that determine normal movement speed. Two long-term benefits of understanding the motor control basis of motor symptoms include the future design of neural prostheses to replace the function of damaged basal ganglia circuits, and the rational design of rehabilitation strategies. This type of understanding, however, remains limited, partly because of limitations in our knowledge of normal motor control. In this article, we review the concept of motor control and describe a few motor symptoms that illustrate the challenges in understanding such symptoms as motor control abnormalities. PMID:22675667

Mazzoni, Pietro; Shabbott, Britne; Cortes, Juan Camilo

2012-01-01

241

Chromosomal Abnormalities Chromosomal abnormalities  

E-print Network

Lecture 6 Chromosomal Abnormalities #12;Chromosomal abnormalities Numeric Polyploidy- abnormal # of chromosome sets Aneuploidy- abnormal chromosome number Structural Deletion syndromes Duplications Ring chromosomes Centromeric fusions (Robertsonian translocations) Insertion Inversion Paracentric Pericentric

Dellaire, Graham

242

HyperBrain: Pathway Quiz 14 - Basal Ganglia  

NSDL National Science Digital Library

One of eighteen quizzes on neuroanatomy accompanying the HyperBrain tutorial. The quizzes require the free Macromedia Flash player plugin. Illustrations modified from "Neuroanatomy - An Atlas of Structures, Sections, and Systems," Fourth Edition, Duane E. Haines, Ph.D., Professor and Chairman, Department of Anatomy, The University of Mississippi Medical Center, Jackson, Mississippi, Copyright 1995. With permission from Lippincott Williams & Wilkins Baltimore, Maryland, USA.Orientation: coronalAnnotated: false

Haines, Duane E.; Stensaas, Suzanne S.

2010-09-17

243

Electrophysiological Effects of Cannabinoids in the Basal Ganglia  

Microsoft Academic Search

\\u000a The hemp plant contains more than 416 chemicals of which more than 60 are cannabinoids (Turner. 1984). These compounds have\\u000a been known for their therapeutic and psychoactive properties for at least 4000 years. The principal rleuroactive constituent\\u000a is ?9-tetrahydrocannabinol (?9-TAC), often used as the prototype of the entire cannabinoid family due to its presence in derivatives ofcannabis sativa(marijuana and hashish)

Anna Lisa Muntoni; Miriam Melis; Marco Diana

244

Basal Ganglia involvement in Wernicke encephalopathy: report of 2 cases.  

PubMed

We present the neuroimaging and clinical findings in 2 nonalcoholic adult patients with WE as assessed by MR imaging. The first patient presented with gait ataxia and changes in consciousness. MR imaging disclosed bilateral lesions in the dorsal striatum and cerebellum. None of the regions typically affected in WE were involved. The second patient showed symmetric lesions in the posterior putamen associated with the alterations frequently and infrequently found WE. PMID:20634304

Zuccoli, G; Cravo, I; Bailey, A; Venturi, A; Nardone, R

2011-08-01

245

Dissociations in Processing Derivational Morphology: The Right Basal Ganglia Involvement  

ERIC Educational Resources Information Center

In the neuropsychological literature, there is converging evidence for a dominant role of the left hemisphere in morphological processing. However, two right hemisphere patients were described with a clear dissociation between impaired derivational morphology and preserved inflectional processing. A recent fMRI experiment confirmed the involvement

Marangolo, Paola; Piras, Fabrizio

2008-01-01

246

Synchronous Oscillations in the Basal-Ganglia-Cortical Network  

E-print Network

(PD) are akinesia (poverty of spontaneous movements and difficulty in initiating a movement/rigid dominant subtype, respectively). The major cellular event leading to PD is the death of midbrain of their species ­ African green (vervet) monkeys tend toward tremor, while macaques do not. Recordings from

247

Dopamine visualized in the basal ganglia of living man  

Microsoft Academic Search

The neurotransmitter dopamine has biological attributes that make it amenable to study by positron emission tomography, unlike many of the 40 or so neurotransmitters that have been identified in the brain. Dopamine deficiency in the nigrostriatal system is a characteristic of Parkinson's disease1, and a disturbance of dopamine metabolism is still widely held to be responsible for the syndrome of

E. S. Garnett; G. Firnau; C. Nahmias

1983-01-01

248

Adenosine A1 receptor activation inhibits LTP in sympathetic ganglia  

Microsoft Academic Search

The effects of adenosine on long-term potentiation of sympathetic ganglia was studied in the isolated superior cervical ganglion of the rat, using extracellularly recorded compound action potential as an index of synaptic transmission. Adenosine in a small concentration (2 ?M) blocked the post-tetanic potentiation without affecting long-term potentiation. Higher concentrations blocked both responses with no significant effect on basal transmission.

Yvonne H Hogan; Rollin Hawkins; Karim A Alkadhi

1998-01-01

249

Abnormal iron homeostasis and neurodegeneration  

PubMed Central

Abnormal iron metabolism is observed in many neurodegenerative diseases, however, only two have shown dysregulation of brain iron homeostasis as the primary cause of neurodegeneration. Herein, we review one of these - hereditary ferritinopathy (HF) or neuroferritinopathy, which is an autosomal dominant, adult onset degenerative disease caused by mutations in the ferritin light chain (FTL) gene. HF has a clinical phenotype characterized by a progressive movement disorder, behavioral disturbances, and cognitive impairment. The main pathologic findings are cystic cavitation of the basal ganglia, the presence of ferritin inclusion bodies (IBs), and substantial iron deposition. Mutant FTL subunits have altered sequence and length but assemble into soluble 24-mers that are ultrastructurally indistinguishable from those of the wild type. Crystallography shows substantial localized disruption of the normally tiny 4-fold pores between the ferritin subunits because of unraveling of the C-termini into multiple polypeptide conformations. This structural alteration causes attenuated net iron incorporation leading to cellular iron mishandling, ferritin aggregation, and oxidative damage at physiological concentrations of iron and ascorbate. A transgenic murine model parallels several features of HF, including a progressive neurological phenotype, ferritin IB formation, and misregulation of iron metabolism. These studies provide a working hypothesis for the pathogenesis of HF by implicating (1) a loss of normal ferritin function that triggers iron accumulation and overproduction of ferritin polypeptides, and (2) a gain of toxic function through radical production, ferritin aggregation, and oxidative stress. Importantly, the finding that ferritin aggregation can be reversed by iron chelators and oxidative damage can be inhibited by radical trapping may be used for clinical investigation. This work provides new insights into the role of abnormal iron metabolism in neurodegeneration. PMID:23908629

Muhoberac, Barry B.; Vidal, Ruben

2013-01-01

250

Basal cell carcinoma  

MedlinePLUS

Basal cell skin cancer; Rodent ulcer; Skin cancer - basal cell; Cancer - skin - basal cell; Nonmelanoma skin cancer; Basal cell NMSC ... Basal cell cancer starts in the top layer of the skin called the epidermis. Most basal cell cancers occur ...

251

Basal Cell Carcinoma  

MedlinePLUS

... and treatments A - D Basal cell carcinoma Basal cell carcinoma Basal cell carcinoma: This skin cancer often ... skin tissue and bone. Learn more about basal cell carcinoma: Basal cell carcinoma: Signs and symptoms Basal ...

252

Abnormal Activation of the Primary Somatosensory Cortex in Spasmodic Dysphonia: An fMRI Study  

PubMed Central

Spasmodic dysphonia (SD) is a task-specific focal dystonia of unknown pathophysiology, characterized by involuntary spasms in the laryngeal muscles during speaking. Our aim was to identify symptom-specific functional brain activation abnormalities in adductor spasmodic dysphonia (ADSD) and abductor spasmodic dysphonia (ABSD). Both SD groups showed increased activation extent in the primary sensorimotor cortex, insula, and superior temporal gyrus during symptomatic and asymptomatic tasks and decreased activation extent in the basal ganglia, thalamus, and cerebellum during asymptomatic tasks. Increased activation intensity in SD patients was found only in the primary somatosensory cortex during symptomatic voice production, which showed a tendency for correlation with ADSD symptoms. Both SD groups had lower correlation of activation intensities between the primary motor and sensory cortices and additional correlations between the basal ganglia, thalamus, and cerebellum during symptomatic and asymptomatic tasks. Compared with ADSD patients, ABSD patients had larger activation extent in the primary sensorimotor cortex and ventral thalamus during symptomatic task and in the inferior temporal cortex and cerebellum during symptomatic and asymptomatic voice production. The primary somatosensory cortex shows consistent abnormalities in activation extent, intensity, correlation with other brain regions, and symptom severity in SD patients and, therefore, may be involved in the pathophysiology of SD. PMID:20194686

Ludlow, Christy L.

2010-01-01

253

Parkinsonism caused by cavernoma located in basal ganglion  

Microsoft Academic Search

Deep-seated cavernoma or cavernous angioma is a very rare clinical entity, as is basal ganglia cavernoma presenting with Parkinsonism. The authors demonstrate a 56-year-old man with a cavernoma located in basal ganglion, who subsequently developed Parkinsonism. The patient refused the surgical intervention, and received L-dopa trial; however, no change in the tremor and bradykinesia was observed in spite of high

Sibel Ertan; Gulcin Benbir; Taner Tanriverdi; Ilker Alver; Mustafa Uzan

2005-01-01

254

Widespread abnormality of the ?-aminobutyric acid-ergic system in Tourette syndrome  

PubMed Central

Dysfunction of the ?-aminobutyric acid-ergic system in Tourette syndrome may conceivably underlie the symptoms of motor disinhibition presenting as tics and psychiatric manifestations, such as attention deficit hyperactivity disorder and obsessivecompulsive disorder. The purpose of this study was to identify a possible dysfunction of the ?-aminobutyric acid-ergic system in Tourette patients, especially involving the basal ganglia-thalamo-cortical circuits and the cerebellum. We studied 11 patients with Tourette syndrome and 11 healthy controls. Positron emission tomography procedure: after injection of 20?mCi of [11C]flumazenil, dynamic emission images of the brain were acquired. Structural magnetic resonance imaging scans were obtained to provide an anatomical framework for the positron emission tomography data analysis. Images of binding potential were created using the two-step version of the simplified reference tissue model. The binding potential images then were spatially normalized, smoothed and compared between groups using statistical parametric mapping. We found decreased binding of GABAA receptors in Tourette patients bilaterally in the ventral striatum, globus pallidus, thalamus, amygdala and right insula. In addition, the GABAA receptor binding was increased in the bilateral substantia nigra, left periaqueductal grey, right posterior cingulate cortex and bilateral cerebellum. These results are consistent with the longstanding hypothesis that circuits involving the basal ganglia and thalamus are disinhibited in Tourette syndrome patients. In addition, the abnormalities in GABAA receptor binding in the insula and cerebellum appear particularly noteworthy based upon recent evidence implicating these structures in the generation of tics. PMID:22577221

Bagic, Anto; Simmons, Janine M.; Mari, Zoltan; Bonne, Omer; Xu, Ben; Kazuba, Diane; Herscovitch, Peter; Carson, Richard E.; Murphy, Dennis L.; Drevets, Wayne C.; Hallett, Mark

2012-01-01

255

Adenosine A1 receptor activation inhibits LTP in sympathetic ganglia.  

PubMed

The effects of adenosine on long-term potentiation of sympathetic ganglia was studied in the isolated superior cervical ganglion of the rat, using extracellularly recorded compound action potential as an index of synaptic transmission. Adenosine in a small concentration (2 microM) blocked the post-tetanic potentiation without affecting long-term potentiation. Higher concentrations blocked both responses with no significant effect on basal transmission. The inhibitory effect appears to be due to activation of adenosine A1 receptors. This was indicated by results from experiments with the A1 agonist N6-cyclopentyladenosine (1 microM) which caused inhibition of the basal transmission as well as long-term potentiation and post-tetanic potentiation. This inhibition was readily antagonized by 8-phenyltheophylline (1 microM), an A1 receptor antagonist. A small enhancement of basal transmission was seen on treatment with 8-phenyltheophylline. The inhibitory effect of N6-cyclopentyladenosine on long-term potentiation was totally prevented when the Ca2+ concentration in the superfusate was doubled (from 2.2 to 4.4 mM). The adenosine A2 receptor agonist 5'-(N-cyclopropyl)-carboxamidoadenosine (1 microM), although caused a slight potentiation of basal transmission, had no significant effect on the post-tetanic potentiation or long-term potentiation. The adenosine transport inhibitors, dipyridamole (2 microM) and S-(4-nitorobenzyl)-6-thioinosine (2 microM) caused significant inhibition of the basal ganglionic transmission without affecting post-tetanic potentiation or long-term potentiation. The effect of dipyradimole on basal transmission was not antagonized in the presence of 8-phenyltheophylline suggesting a non-specific action. The results suggest that exogenous adenosine can inhibit both post-tetanic potentiation and long-term potentiation in sympathetic ganglia, probably by activation of presynaptic A1 receptors. The results also suggest that endogenous adenosine, which is probably released in minute amounts, may only modulate basal transmission without influencing induction or maintenance of long-term potentiation in the superior cervical ganglion. PMID:9756986

Hogan, Y H; Hawkins, R; Alkadhi, K A

1998-10-01

256

Persistence of cerebral metabolic abnormalities in chronic schizophrenia as determined by positron emission tomography  

SciTech Connect

Local cerebral metabolic rates were determined by positron emission tomography and the deoxyglucose method in a group of 10 chronic schizophrenic subjects before and after somatic treatment and in eight normal subjects. Before treatment, schizophrenic subjects had markedly lower absolute metabolic activity than did normal controls in both frontal and temporal regions and a trend toward relative hyperactivity in the basal ganglia area. After treatment, their metabolic rates approached those seen in normal subjects in nearly all regions except frontal. Persistence of diminished frontal metabolism was manifested as significant relative hypofrontality. These findings suggest specific loci of aberrant cerebral functioning in chronic schizophrenia and the utility of positron emission tomography in characterizing these abnormalities.

Wolkin, A.; Jaeger, J.; Brodie, J.D.; Wolf, A.P.; Fowler, J.; Rotrosen, J.; Gomez-Mont, F.; Cancro, R.

1985-05-01

257

Abnormal Striatal Dopaminergic Neurotransmission during Rest and Task Production in Spasmodic Dysphonia  

PubMed Central

Spasmodic dysphonia is a primary focal dystonia characterized by involuntary spasms in the laryngeal muscles during speech production. The pathophysiology of spasmodic dysphonia is thought to involve structural and functional abnormalities in the basal gangliathalamo-cortical circuitry; however, neurochemical correlates underpinning these abnormalities as well as their relations to spasmodic dysphonia symptoms remain unknown. We used positron emission tomography with the radioligand [11C]raclopride (RAC) to study striatal dopaminergic neurotransmission at the resting state and during production of symptomatic sentences and asymptomatic finger tapping in spasmodic dysphonia patients. We found that patients, compared to healthy controls, had bilaterally decreased RAC binding potential (BP) to striatal dopamine D2/D3 receptors on average by 29.2%, which was associated with decreased RAC displacement (RAC ?BP) in the left striatum during symptomatic speaking (group average difference 10.2%), but increased RAC ?BP in the bilateral striatum during asymptomatic tapping (group average difference 10.1%). Patients with more severe voice symptoms and subclinically longer reaction time to initiate the tapping sequence had greater RAC ?BP measures, while longer duration of spasmodic dysphonia was associated with a decrease in task-induced RAC ?BP. Decreased dopaminergic transmission during symptomatic speech production may represent a disorder-specific pathophysiological trait involved in symptom generation, whereas increased dopaminergic function during unaffected task performance may be explained by a compensatory adaptation of the nigrostriatal dopaminergic system possibly due to decreased striatal D2/D3 receptor availability. These changes can be linked to the clinical and subclinical features of spasmodic dysphonia and may represent the neurochemical basis of basal ganglia alterations in this disorder. PMID:24027271

Berman, Brian D.; Herscovitch, Peter; Hallett, Mark

2013-01-01

258

Communication between neuronal somata and satellite glial cells in sensory ganglia  

PubMed Central

Studies of the structural organization and functions of the cell body of a neuron (soma) and its surrounding satellite glial cells (SGCs) in sensory ganglia have led to the realization that SGCs actively participate in the information processing of sensory signals from afferent terminals to the spinal cord. SGCs use a variety ways to communicate with each other and with their enwrapped soma. Changes in this communication under injurious conditions often lead to abnormal pain conditions. What are the mechanisms underlying the neuronal soma and SGC communication in sensory ganglia and how do tissue or nerve injuries affect the communication? are the main questions addressed in this review. PMID:23918214

Huang, Li-Yen M.; Gu, Yanping; Chen, Yong

2013-01-01

259

Seizure-induced brain lesions: a wide spectrum of variably reversible MRI abnormalities.  

PubMed

Introduction MRI abnormalities in the postictal period might represent the effect of the seizure activity, rather than its structural cause. Material and Methods Retrospective review of clinical and neuroimaging charts of 26 patients diagnosed with seizure-related MR-signal changes. All patients underwent brain-MRI (1.5-Tesla, standard pre- and post-contrast brain imaging, including DWI-ADC in 19/26) within 7 days from a seizure and at least one follow-up MRI, showing partial or complete reversibility of the MR-signal changes. Extensive clinical work-up and follow-up, ranging from 3 months to 5 years, ruled out infection or other possible causes of brain damage. Seizure-induced brain-MRI abnormalities remained a diagnosis of exclusion. Site, characteristics and reversibility of MRI changes, and association with characteristics of seizures were determined. Results MRI showed unilateral (13/26) and bilateral abnormalities, with high (24/26) and low (2/26) T2-signal, leptomeningeal contrast-enhancement (2/26), restricted diffusion (9/19). Location of abnormality was cortical/subcortical, basal ganglia, white matter, corpus callosum, cerebellum. Hippocampus was involved in 10/26 patients. Reversibility of MRI changes was complete in 15, and with residual gliosis or focal atrophy in 11 patients. Reversibility was noted between 15 and 150 days (average, 62 days). Partial simple and complex seizures were associated with hippocampal involvement (p=0.015), status epilepticus with incomplete reversibility of MRI abnormalities (p=0.041). Conclusions Seizure or epileptic status can induce transient, variably reversible MRI brain abnormalities. Partial seizures are frequently associated with hippocampal involvement and status epilepticus with incompletely reversible lesions. These seizure-induced MRI abnormalities pose a broad differential diagnosis; increased awareness may reduce the risk of misdiagnosis and unnecessary intervention. PMID:23787273

Cianfoni, A; Caulo, M; Cerase, A; Della Marca, G; Falcone, C; Di Lella, G M; Gaudino, S; Edwards, J; Colosimo, C

2013-11-01

260

Structural brain abnormalities in cervical dystonia  

PubMed Central

Background Idiopathic cervical dystonia is characterized by involuntary spasms, tremors or jerks. It is not restricted to a disturbance in the basal ganglia system because non-conventional voxel-based MRI morphometry (VBM) and diffusion tensor imaging (DTI) have detected numerous regional changes in the brains of patients. In this study scans of 24 patients with cervical dystonia and 24 age-and sex-matched controls were analysed using VBM, DTI and magnetization transfer imaging (MTI) using a voxel-based approach and a region-of-interest analysis. Results were correlated with UDRS, TWSTRS and disease duration. Results We found structural alterations in the basal ganglia; thalamus; motor cortex; premotor cortex; frontal, temporal and parietal cortices; visual system; cerebellum and brainstem of the patients with dystonia. Conclusions Cervical dystonia is a multisystem disease involving several networks such as the motor, sensory and visual systems. PMID:24131497

2013-01-01

261

Abuse of Amphetamines and Structural Abnormalities in Brain  

PubMed Central

We review evidence that structural brain abnormalities are associated with abuse of amphetamines. A brief history of amphetamine use/abuse, and evidence for toxicity is followed by a summary of findings from structural magnetic resonance imaging (MRI) studies of human subjects who had abused amphetamines and children who were exposed to amphetamines in utero. Evidence comes from studies that used a variety of techniques that include manual tracing, pattern matching, voxel-based, tensor-based, or cortical thickness mapping, quantification of white matter signal hyperintensities, and diffusion tensor imaging. Ten studies compared controls to individuals who were exposed to methamphetamine. Three studies assessed individuals exposed to 3-4-methylenedioxymethamphetamine (MDMA). Brain structural abnormalities were consistently reported in amphetamine abusers, as compared to control subjects. These included lower cortical gray matter volume and higher striatal volume than control subjects. These differences might reflect brain features that could predispose to substance dependence. High striatal volumes might also reflect compensation for toxicity in the dopamine-rich basal ganglia. Prenatal exposure was associated with striatal volume that was below control values, suggesting that such compensation might not occur in utero. Several forms of white matter abnormality are also common, and may involve gliosis. Many of the limitations and inconsistencies in the literature relate to techniques and cross-sectional designs, which cannot infer causality. Potential confounding influences include effects of pre-existing risk/protective factors, development, gender, severity of amphetamine abuse, abuse of other drugs, abstinence, and differences in lifestyle. Longitudinal designs in which multimodal datasets are acquired and are subjected to multivariate analyses would enhance our ability to provide general conclusions regarding the associations between amphetamine abuse and brain structure. PMID:18991959

Berman, Steven; O'Neill, Joseph; Fears, Scott; Bartzokis, George; London, Edythe D.

2009-01-01

262

Central nervous system abnormalities in asymptomatic young patients with Sbeta-thalassemia.  

PubMed

Twenty-one children and young adults with sickle/beta-thalassemia without overt stroke were examined with magnetic resonance imaging and angiography (MRA), transcranial Doppler (TCD), visual (VEP) and median nerve somatosensory (SEP)-evoked potential recordings, and neuropsychological testing (Wechsler Intelligence Scale [WISC-III]). Eight (38%) had silent infarction in the parietooccipital cortex, deep white matter, or basal ganglia, including two of three with previous seizures. Of 17 undergoing TCD, none had maximum middle cerebral artery (MCA) velocities greater than 126cm/sec, but 9 were abnormal, with low velocities and difficulty in tracking the MCA and/or asymmetry. Three patients had abnormal MRA, one of whom also had silent infarction. One patient had pathological VEP recordings, whereas all SEP recordings were normal. WISC-III was performed in all 11 children, 4 with silent infarction: all but 1 had IQ scores greater than 85 (mean, 97.7; standard deviation, 14.2). We conclude that Greek children and young adults with Sbeta-thalassemia and no history of clinical stroke have TCD abnormalities and silent infarction similar to those reported in children and adolescents with sickle cell anemia, but cognitive function is not necessarily compromised. International collaboration is needed to establish the risk factors for central nervous system sequelae in patients with sickle cell disease, including Sbeta-thalassemia, leading to evidence-based prevention. PMID:15174017

Zafeiriou, Dimitrios I; Prengler, Mara; Gombakis, Nikos; Kouskouras, Konsantinos; Economou, Marina; Kardoulas, Achileas; Tsantali, Chaido; Dimitriadis, Athanasios; Athanasiou, Miranta; Kirkham, Fenella J

2004-06-01

263

Pravastatin reduces microvascular basal lamina damage following focal cerebral ischemia and reperfusion.  

PubMed

Transient ischemia has been shown to damage the basal lamina of the cerebral microvasculature. Other studies proved statins to be beneficial to non-cerebral microvessels. The aim of this study was to determine whether pravastatin pretreatment ameliorates microvascular basal lamina damage following transient ischemia. Using the suture model, we subjected 15 rats to focal ischemia (3 h) and reperfusion (24 h). Rats received pravastatin (20 mg/kg/day) or saline for 4 weeks prior to the experiment. The outcome was determined by a behavior test and the infarct size. Collagen type IV, a marker for an intact basal lamina, and hemoglobin extravasation were measured by Western blot analysis. A ratio (in percentage) between ischemic and contralateral hemispheres was calculated. Pravastatin pretreatment resulted in a significantly better neurological outcome and reduced infarct size (15 +/- 0.5 and 59 +/- 10 mm(3), respectively) compared with controls (12.25 +/- 0.4 and 167 +/- 13 mm(3), respectively, P < 0.01 for both). In controls, loss of collagen type IV was seen in the basal ganglia and in the cortex (43 +/- 4 and 64 +/- 5%, respectively). Pravastatin prevented significant collagen loss (basal ganglia: 106 +/- 17%; cortex: 112 +/- 14%, P < 0.01 for both) and significantly reduced the hemoglobin extravasation compared with controls in the basal ganglia (198 +/- 49 vs. 553 +/- 47%, P < 0.01). Pravastatin pretreatment resulted in a reduction of microvascular basal lamina damage and hemoglobin extravasation following transient ischemia. Pravastatin seems to protect the cerebral microvascular system. PMID:16836638

Trinkl, Andreas; Vosko, Milan R; Wunderlich, Nathalie; Dichgans, Martin; Hamann, Gerhard F

2006-07-01

264

Basal Cell Carcinoma (BCC)  

MedlinePLUS

newsletter | contact Share | Basal Cell Carcinoma (BCC) Information for adults A A A The nodular form of basal cell carcinoma is usually skin-colored with ... the general health of the patient. Nodular basal cell carcinomas: Freezing (cryosurgery) with liquid nitrogen Very cold ...

265

[Walking abnormalities in children].  

PubMed

Walking is a spontaneous movement termed locomotion that is promoted by activation of antigravity muscles by serotonergic (5HT) neurons. Development of antigravity activity follows 3 developmental epochs of the sleep-wake (S-W) cycle and is modulated by particular 5HT neurons in each epoch. Activation of antigravity activities occurs in the first epoch (around the age of 3 to 4 months) as restriction of atonia in rapid eye movement (REM) stage and development of circadian S-W cycle. These activities strengthen in the second epoch, with modulation of day-time sleep and induction of crawling around the age of 8 months and induction of walking by 1 year. Around the age of 1 year 6 months, absence of guarded walking and interlimb cordination is observed along with modulation of day-time sleep to once in the afternoon. Bipedal walking in upright position occurs in the third epoch, with development of a biphasic S-W cycle by the age of 4-5 years. Patients with infantile autism (IA), Rett syndrome (RTT), or Tourette syndrome (TS) show failure in the development of the first, second, or third epoch, respectively. Patients with IA fail to develop interlimb coordination; those with RTT, crawling and walking; and those with TS, walking in upright posture. Basic pathophysiology underlying these condition is failure in restricting atonia in REM stage; this induces dysfunction of the pedunculopontine nucleus and consequently dys- or hypofunction of the dopamine (DA) neurons. DA hypofunction in the developing brain, associated with compensatory upward regulation of the DA receptors causes psychobehavioral disorders in infancy (IA), failure in synaptogenesis in the frontal cortex and functional development of the motor and associate cortexes in late infancy through the basal ganglia (RTT), and failure in functional development of the prefrontal cortex through the basal ganglia (TS). Further, locomotion failure in early childhood causes failure in development of functional specialization of the cortex through the spinal stepping generator-fastigial nucleus-thalamus-cortex pathway. Early detection of locomotion failure and early adjustment of this condition through environmental factors can prevent the development of higher cortical dysfunction. PMID:21068458

Segawa, Masaya

2010-11-01

266

Meiotic abnormalities  

SciTech Connect

Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

NONE

1993-12-31

267

Chromosomal abnormalities  

SciTech Connect

Cytogenetic studies from the peripheral blood of a patient with malignant lymphoma and rhematoid arthritis who was treated with intra-articular gold Au 198 revealed mosaicism with a normal female metaphase and a 43-chromosome metaphase. The abnormal cell line showed six missing normal chromosomes and three morphologically abnormal chromosomes. The trypsin-digested G-banding metaphases showed that the marker chromosomes were an isochromosome of the long arm of chromosome 17, a translocated chromosome that involved the long arm of chromosome 4 and a chromosome 16, and a translocated chromosome that involved the long arm of chromosome 4 and a chromosome 5. It is tempting to conclude that these abnormalities were due to the gold Au 198 treatment, but we cannot exclude other possibilities.

Goh, K.; Jacox, R.F.; Anderson, F.W.

1980-09-01

268

Nevoid Basal Cell Carcinoma Syndrome  

MedlinePLUS

... Carcinoma Syndrome Request Permissions Download PDF Nevoid Basal Cell Carcinoma Syndrome This section has been reviewed and ... Editorial Board , 11/2013 What is Nevoid Basal Cell Carcinoma Syndrome? Nevoid Basal Cell Carcinoma Syndrome (NBCCS) ...

269

Volumetric Segmentation of Multiple Basal Ganglia Mustafa Gokhan Uzunbas, Octavian Soldea, Mujdat Cetin,  

E-print Network

-mail: ahmet.ekin@philips.com This work was partially supported by the European Commission under Grants FP6. In our previous work [9], we introduced prior probability densities on the coupled (joint) shapes is with the Video Processing and Analysis Group, Philips Research, Europe, Eindhoven, 5656AE, The Netherlands. e

Yanikoglu, Berrin

270

Two forms of iron as an intrinsic contrast agent in the basal ganglia of PKAN patients.  

PubMed

Iron deposits in the human brain can be considered as intrinsic contrast agents for magnetic resonance imaging and are used as markers of neurodegeneration accompanied by brain-iron accumulation. We studied one of them - panthotenate-kinase associated neurodegeneration (PKAN) - by using relaxometry at 1.5, 3.0 and 7 T in a group of six patients; we also measured a group of five volunteers for comparison. Based on the magnetic field dependency of antiferromagnetic ferritin and maghemite iron oxide nanoparticle relaxivities, we derived a two-component model for the description of iron deposits in the globus pallidus of PKAN patients. According to this model, we estimated the iron content in PKAN patients as 391 g/ml of antiferromagnetic iron (ferritin) and 1.1 g/ml of ferrimagnetic iron, compared with 178 g/ml of iron in ferritin found in controls. This two-component model explains the nonlinear shape of the relaxometric curves in in vivo measurements of the relaxation rates of PKAN patients and is supported by histological findings in the original reports on PKAN patients. PMID:22991317

Dezortova, Monika; Herynek, Vit; Krssak, Martin; Kronerwetter, Claudia; Trattnig, Siegfried; Hajek, Milan

2012-01-01

271

Multiple Output Channels in the Basal Ganglia John E. Hoover; Peter L. Strick  

E-print Network

, Vol. 259, No. 5096. (Feb. 5, 1993), pp. 819-821. Stable URL: http://links.jstor.org/sici?sici=0036 for the Advancement of Science. Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/about/terms.html. JSTOR's Terms and Conditions of Use

Sereno, Martin

272

Hyporesponsive Reward Anticipation in the Basal Ganglia following Severe Institutional Deprivation Early in Life  

ERIC Educational Resources Information Center

Severe deprivation in the first few years of life is associated with multiple difficulties in cognition and behavior. However, the brain basis for these difficulties is poorly understood. Structural and functional neuroimaging studies have implicated limbic system structures as dysfunctional, and one functional imaging study in a heterogeneous

Mehta, Mitul A.; Gore-Langton, Emma; Golembo, Nicole; Colvert, Emma; Williams, Steven C. R.; Sonuga-Barke, Edmund

2010-01-01

273

Apoptosis in the basal ganglia of the developing human nervous system  

Microsoft Academic Search

Programmed cell death (PCD) plays a crucial role in the development of the central nervous system through controlling neuronal numbers and adequate synaptic connections. PCD has been considered to occur in the form of apoptosis. To examine how apoptosis occurs in the developing human brain, we performed a morphometric TUNEL study, using a commercially available kit (ApopTag Kit, Oncor Inc.).

Kyoko Itoh; Kyoko Suzuki; Karl Bise; Hiroshi Itoh; Parviz Mehraein; Serge Weis

2001-01-01

274

Severity of dysfluency correlates with basal ganglia activity in persistent developmental stuttering  

Microsoft Academic Search

Previous studies suggest that anatomical anomalies [Foundas, A. L., Bollich, A. M., Corey, D. M., Hurley, M., & Heilman, K. M. (2001). Anomalous anatomy of speech-language areas in adults with persistent developmental stuttering. Neurology, 57, 207215; Foundas, A. L., Corey, D. M., Angeles, V., Bollich, A. M., Crabtree-Hartman, E., & Heilman, K. M. (2003). Atypical cerebral laterality in adults with

Anne-Lise Giraud; Katrin Neumann; Anne-Catherine Bachoud-Levi; Alexander W. von Gudenberg; Harald A. Euler; Heinrich Lanfermann; Christine Preibisch

2008-01-01

275

Projections from the primary somatosensory cortex to basal ganglia and thalamus in the monkey  

Microsoft Academic Search

Radioactive amino acids were injected into the postcentral cortex (areas 3, 1 and 2) in 6 monkeys (Macaca fascicularis). Fibers were traced to the ipsilateral putamen, to Olszewski's n. ventralis posterior lateralis pars caudalis, n. ventralis posterior medialis and inferior, to n. pulvinaris oralis, n. suprageniculatus and corpus geniculatum mediale pars magnocellularis. Furthermore, there were faint postcentral projections to claustrum,

H. Knzle

1977-01-01

276

The effects of cues on neurons in the basal ganglia in Parkinson's disease  

E-print Network

Visual cues open a unique window to the understanding of Parkinson's disease (PD). These cues can temporarily but dramatically improve PD motor symptoms. Although details are unclear, cues are believed to suppress pathological ...

Brown, Emery N.

277

Behavioral/Systems/Cognitive Low-Pass Filter Properties of Basal GangliaCorticalMuscle  

E-print Network

in the Normal and MPTP Primate Model of Parkinsonism Michal Rivlin-Etzion,1,2 Odeya Marmor,1 Guy Saban,1 Boris cortex; frequency domain; transfer function; Parkinson's disease Introduction The BG are commonly viewed of the current neurosurgical treatment of Parkinson's disease (PD) (Bergman et al., 1990; Benabid et al., 2006

Friedman, Nir

278

A Rap Guanine Nucleotide Exchange Factor Enriched Highly in the Basal Ganglia  

Microsoft Academic Search

Ras proteins, key regulators of growth, differentiation, and malignant transformation, recently have been implicated in synaptic function and region-specific learning and memory functions in the brain. Rap proteins, members of the Ras small G protein superfamily, can inhibit Ras signaling through the Ras\\/Raf-1\\/mitogen-activated protein (MAP) kinase pathway or, through B-Raf, can activate MAP kinase. Rap and Ras proteins both can

Hiroaki Kawasaki; Gregory M. Springett; Shinichiro Toki; Juan J. Canales; Patricia Harlan; Justin P. Blumenstiel; Emy J. Chen; I. Amy Bany; Naoki Mochizuki; Amy Ashbacher; Michiyuki Matsuda; David E. Housman; Ann M. Graybiel

1998-01-01

279

Preliminary observation of elevated levels of nanocrystalline iron oxide in the basal ganglia of neuroferritinopathy patients  

PubMed Central

Magnetometry analysis of brain tissue sub-samples from two neuroferritinopathy patients provides a preliminary indication that the amount of magnetic iron compounds associated with this rare disease is significantly larger than in age/sex-matched controls from the same region of the brain. The primary iron compounds contributing to the remanant magnetization of the tissue above 50 K and at body temperature, are both blocked and superparamagnetic (SPM) biogenic magnetite (Fe3O4) and/or maghemite (?-Fe2O3). The concentration of SPM magnetite is significant and appears to be proportional to the concentration of ferritin, which varies with progression of the disease. The mutated ferritin protein appears to be responsible for the presence of iron oxide nano-particules, which in turn could be responsible for extensive damage in the brain. PMID:17097860

Hautot, Dimitri; Pankhurst, Quentin A.; Morris, Chris M.; Curtis, Andrew; Burn, John; Dobson, Jon

2007-01-01

280

Calcification of basal ganglia, postoperative hypoparathyroidism and extrapyramidal, cerebellar, pyramidal motor manifestations  

Microsoft Academic Search

A patient is described who 32 years after thyroidectomy developed a chronic progressive syndrome due to hypoparathyroidism, with multiple extrapyramidal signs (faciobuccolingual dyskinesias, choreiform and athetotic movements of upper extremities, tremor of hands, cogwheel phenomenon), cerebellar manifestations (dysarthria, dysgraphia, mild gait ataxia), and pyramidal signs as well as an organic psychosis and epilepsy. A CT scan showed calcification of the

P. Kartin; M. Zupevc; T. Poga?nik; M. ?erk

1982-01-01

281

C. Haegelen Automated segmentation of basal ganglia and deep brain structures in MRI  

E-print Network

Neurological Institute, 3801 University Street Montreal, QC, H3A 2B4, CANADA 2 INSERM, U746, Faculty-weighted magnetic resonance (MR) image templates were created by averaging MR images of 57 patients on 10 MR scans of Parkinson's patients as a gold standard. We compared the manual segmentations

Paris-Sud XI, Université de

282

Basal Ganglia Calcification (BGC) in Down's Syndrome (DS)?Another Manifestation of Premature Aging  

Microsoft Academic Search

Not Available Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints

K. E. Wisniewski; J. H. French; J. F. Rosen; P. B. Kozlowski; M. Tenner; H. M. Wisniewski

1982-01-01

283

Mini-Symposium Converging Evidence for a Fronto-Basal-Ganglia Network for  

E-print Network

; brain stimulation; attention deficit hyperactivity disorder; imaging Imagine you are at an intersection such as Attention Deficit Hyperactiv- ity Disorder (ADHD). The Stop signal paradigm This cognitive psychology Medical Center Utrecht, The Netherlands Key words: Stop signal; cognitive control; response inhibition

Logan, Gordon D.

284

Interacting cortical and basal ganglia networks underlying finding and tapping to the musical beat.  

PubMed

Humans are able to find and tap to the beat of musical rhythms varying in complexity from children's songs to modern jazz. Musical beat has no one-to-one relationship with auditory features-it is an abstract perceptual representation that emerges from the interaction between sensory cues and higher-level cognitive organization. Previous investigations have examined the neural basis of beat processing but have not tested the core phenomenon of finding and tapping to the musical beat. To test this, we used fMRI and had musicians find and tap to the beat of rhythms that varied from metrically simple to metrically complex-thus from a strong to a weak beat. Unlike most previous studies, we measured beat tapping performance during scanning and controlled for possible effects of scanner noise on beat perception. Results showed that beat finding and tapping recruited largely overlapping brain regions, including the superior temporal gyrus (STG), premotor cortex, and ventrolateral PFC (VLPFC). Beat tapping activity in STG and VLPFC was correlated with both perception and performance, suggesting that they are important for retrieving, selecting, and maintaining the musical beat. In contrast BG activity was similar in all conditions and was not correlated with either perception or production, suggesting that it may be involved in detecting auditory temporal regularity or in associating auditory stimuli with a motor response. Importantly, functional connectivity analyses showed that these systems interact, indicating that more basic sensorimotor mechanisms instantiated in the BG work in tandem with higher-order cognitive mechanisms in PFC. PMID:23163420

Kung, Shu-Jen; Chen, Joyce L; Zatorre, Robert J; Penhune, Virginia B

2013-03-01

285

Structural correlates of efficient GABAergic transmission in the basal ganglia-thalamus pathway.  

PubMed

Giant inhibitory terminals with multiple synapses, the counterparts of excitatory "detonator" or "driver" terminals, have not been described in the forebrain. Using three-dimensional reconstructions of electron microscopic images, we quantitatively characterize a GABAergic pathway that establishes synaptic contacts exclusively via multiple synapses. Axon terminals of the nigrothalamic pathway formed, on average, 8.5 synapses on large-diameter dendrites and somata of relay cells in the ventromedial nucleus of the rat thalamus. All synapses of a given terminal converged on a single postsynaptic element. The vast majority of the synapses established by a single terminal were not separated by astrocytic processes. Nigrothalamic terminals in the macaque monkey showed the same ultrastructural features both in qualitative and quantitative terms (the median number of synapse per target was also 8.5). The individual synapses were closely spaced in both species. The nearest-neighbor synaptic distances were 169 nm in the rat and 178 nm in the monkey. The average number of synapses within 0.75 microm from any given synapse was 3.8 in the rat and 3.5 in the monkey. The arrangement of synapses described in this study creates favorable conditions for intersynaptic spillover of GABA among the multiple synapses of a single bouton, which can result in larger charge transfer. This could explain faithful and efficient GABAergic signal transmission in the nigrothalamic pathway in the healthy condition and during Parkinson's disease. In addition, our structural data suggest that the rodent nigrothalamic pathway can be a valid model of the primate condition, when the mechanism of GABAergic transmission is studied. PMID:18354012

Bodor, Agnes L; Giber, Kristf; Rov, Zita; Ulbert, Istvn; Acsdy, Lszl

2008-03-19

286

Structural Correlates of Efficient GABAergic Transmission in the Basal Ganglia-Thalamus Pathway  

PubMed Central

Giant inhibitory terminals with multiple synapses, the counterparts of excitatory detonator or driver terminals, have not been described in the forebrain. Using three-dimensional reconstructions of electron microscopic images, we quantitatively characterize a GABAergic pathway that establishes synaptic contacts exclusively via multiple synapses. Axon terminals of the nigrothalamic pathway formed, on average, 8.5 synapses on large-diameter dendrites and somata of relay cells in the ventromedial nucleus of the rat thalamus. All synapses of a given terminal converged on a single postsynaptic element. The vast majority of the synapses established by a single terminal were not separated by astrocytic processes. Nigrothalamic terminals in the macaque monkey showed the same ultrastructural features both in qualitative and quantitative terms (the median number of synapse per target was also 8.5). The individual synapses were closely spaced in both species. The nearest-neighbor synaptic distances were 169 nm in the rat and 178 nm in the monkey. The average number of synapses within 0.75 ?m from any given synapse was 3.8 in the rat and 3.5 in the monkey. The arrangement of synapses described in this study creates favorable conditions for intersynaptic spillover of GABA among the multiple synapses of a single bouton, which can result in larger charge transfer. This could explain faithful and efficient GABAergic signal transmission in the nigrothalamic pathway in the healthy condition and during Parkinsons disease. In addition, our structural data suggest that the rodent nigrothalamic pathway can be a valid model of the primate condition, when the mechanism of GABAergic transmission is studied. PMID:18354012

Bodor, gnes L.; Giber, Kristf; Rov, Zita; Ulbert, Istvn; Acsdy, Lszl

2009-01-01

287

Behavioural context and a distributed system: metabolic mapping studies of the basal ganglia.  

PubMed

Behavioural context is known to affect neural activity in the striatum. Responses of single cells increase to rewarding stimuli, or drop out as a bar press or saccade is learned. Networks that can accomplish a unique response to changing contexts are of particular interest to systems neuroscience and were a part of Hebb's interest in perception and learning. An overall map of the striatum that localizes changes related to this remarkable phenomenon of contextual responses contributes to our understanding of anatomical substrates of neural systems that integrate information, and may lead us to new striatal regions to study synaptic mechanisms of learning. PMID:10389488

Lidsky, T I; Brown, L L

1999-03-01

288

Basal Ganglia Disorders Associated with Imbalances in the Striatal Striosome and Matrix Compartments  

E-print Network

The striatum is composed principally of GABAergic, medium spiny striatal projection neurons (MSNs) that can be categorized based on their gene expression, electrophysiological profiles, and inputoutput circuits. Major ...

Crittenden, Jill R.

289

Error Correction, the Basal Ganglia, and the Cerebellum Ph.D. Dissertation  

E-print Network

HUNTINGTON'S DISEASE BACKGROUND ..........................................................................2 SENSORIMOTOR PROCESSING IN HUNTINGTON'S DISEASE ...............................................4 CEREBELLAR ....................................................................................................12 CHAPTER 2 - HUNTINGTON'S DISEASE BEGINS AS A DYSFUNCTION IN ERROR FEEDBACK CONTROL

Shadmehr, Reza

290

Effect of thyrotropin releasing hormone on the accumulation of cAMP by parietal ganglia of a gastropod.  

PubMed

1. We had previously shown that thyrotropin releasing hormone (TRH) can stimulate the in vitro accumulation of cAMP by the parietal ganglia of the pond snail Lymnaea emarginata (Grimm-Jrgensen, 1980). 2. The mechanism by which TRH affects cAMP metabolism in parietal ganglia was further studied. 3. The TRH-induced accumulation of cAMP is preceded by a lag period and is of long duration. 4. TRH does not stimulate basal or guanylylimidodiphosphate-stimulated adenylate cyclase activity and is unable to cause an increase in cAMP accumulation when the incubation is carried out in the presence of a phosphodiesterase inhibitor. 5. This finding is compatible with the hypothesis that TRH may cause an increase in cAMP accumulation by means of decreasing phosphodiesterase activity. 6. When the ganglia were incubated with 3H-TRH and the localization of the labeled TRH examined by autoradiographic techniques, reduced silver grains were present only over glial and connective tissue elements. 7. The observed effect of TRH on the cAMP metabolism in parietal ganglia may be due to its action on non-neuronal cells. PMID:6188574

Grimm-Jorgensen, Y

1983-01-01

291

Basal cell carcinoma - diagnosis  

PubMed Central

Basal cell carcinoma is the most common skin cancer in the Caucasian population. The cancer arises in sun exposed areas of the skin. The incidence of morbidity is high and it is still growing. The metastatic rate is low, but the enlarging tumor may cause severe tissue disfigurement and a poor cosmetic outcome. The diagnosis is usually clinical but there are many subtypes of this carcinoma and correct diagnosis is the clue to appropriate treatment of the lesion. The main problem in basal cell carcinoma management is the high recurrence rate. PMID:24592119

Bowszyc-Dmochowska, Monika; Strzelecka-Weklar, Daria; Danczak-Pazdrowska, Aleksandra; Adamski, Zygmunt

2013-01-01

292

Cerebellar abnormalities in Huntington's disease: A role in motor and psychiatric impairment?  

PubMed

The cerebellum has received limited attention in Huntington's disease (HD), despite signs of possible cerebellar dysfunction, including motor incoordination and impaired gait, which are currently attributed to basal ganglia atrophy and disrupted fronto-striatal circuits. This study is the first to investigate a potential contribution of macro- and microstructural cerebellar damage to clinical manifestations of HD. T1- and diffusion-weighted 3T magnetic resonance imaging (MRI) scans were obtained from 12 controls and 22 early-stage HD participants. Manual delineation and voxel-based morphometry were used to assess between-group differences in cerebellar volume, and diffusion metrics were compared between groups within the cerebellar gray and white matter. Associations between these imaging measures and clinical scores were examined within the HD group. Reduced paravermal volume was detected in HD compared with controls using voxel-based morphometry (P?abnormalities were detected in both cerebellar gray matter and white matter. Smaller cerebellar volumes, although not significantly reduced, were significantly associated with impaired gait and psychiatric morbidity and of borderline significance with pronate/supinate-hand task performance. Abnormal cerebellar diffusion was associated with increased total motor score, impaired saccade initiation, tandem walking, and timed finger tapping. In conclusion, atrophy of the paravermis, possibly encompassing the cerebellar nuclei, and microstructural abnormalities within the cerebellum may contribute to HD neuropathology. Aberrant cerebellar diffusion and reduced cerebellar volume together associate with impaired motor function and increased psychiatric symptoms in stage I HD, potentially implicating the cerebellum more centrally in HD presentation than previously recognized. 2014 International Parkinson and Movement Disorder Society. PMID:25123926

Rees, Elin M; Farmer, Ruth; Cole, James H; Haider, Salman; Durr, Alexandra; Landwehrmeyer, Bernhard; Scahill, Rachael I; Tabrizi, Sarah J; Hobbs, Nicola Z

2014-11-01

293

Nodose ganglia-modulatory effects on respiration.  

PubMed

The key role of the vagus nerves in the reflex control of breathing is generally accepted. Cardiopulmonary vagal receptors and their afferent connection with the medullary respiratory centers secures the proper regulatory feedback. Section of the vagi at the midcervical level interrupts primary vagal reflexes and those due to activation of lung afferents by neuroactive substances. In this context the present review focuses on the reflex contribution of the inferior (nodose) vagal ganglia to the respiratory pattern, considering that this structure contains perikarya of vagal afferent neurons which house neurotransmitters, neuropeptides and neurochemical substances. In experimental animals with removed sensory input from the lungs (midcervical vagotomy) the following evidence was reported. Transient respiratory suppression in the form of apnoea, occurring after systemic injection of serotonin, adenosine triphosphate and anandamide (N-arachidonoyl-ethanolamine-endogenous cannabinoid neurotransmitter), which was abrogated by nodose ganglionectomy. Preserved nodose-NTS connection conditioned respiratory depression affecting the timing component of the breathing pattern evoked by N-6-cyclopentyl-adenosine (CPA) and inhibition of both respiratory constituents induced by NPY. Stimulatory effect of NPY13-36 on tidal volume required nodosal connection. The cardiovascular effects of majority of the tested substances occurred beyond the nodose ganglia (with exclusion of serotonin and anandamide). PMID:23489183

Kaczy?ska, K; Szereda-Przestaszewska, M

2013-07-18

294

Vulvar basal cell carcinoma.  

PubMed

Although the basal cell carcinoma (BCC) is the most common malignancy of skin, it is rarely seen in vulva and constitutes 2% to 4% of all vulvar cancers. The cause is unknown but, chronic vulvar irritation is the most important underlying factor. The patients over 60 years are affected more frequently than younger ones. PMID:23455815

Kara, Mustafa; Colgecen, E; Yildirim, Erdogan Nilsen

2012-01-01

295

Can a subgroup of OCD patients with motor abnormalities and poor therapeutic response be identified?  

Microsoft Academic Search

Rationale: In a subgroup of patients with ob- sessive-compulsive disorder (OCD), motor soft signs, tics and other movement disorders can be observed, indicat- ing a special pathogenetic involvement of basal ganglia. Objectives: The main objective of this study was to verify the hypothesis that such motor dysfunction characterises a subgroup of OCD patients with poor treatment response. For assessing even

Roland Mergl; Paraskevi Mavrogiorgou; Georg Juckel; Michael Zaudig; Ulrich Hegerl

2005-01-01

296

Calcium Signaling in Intact Dorsal Root Ganglia  

PubMed Central

Background Ca2+ is the dominant second messenger in primary sensory neurons. In addition, disrupted Ca2+ signaling is a prominent feature in pain models involving peripheral nerve injury. Standard cytoplasmic Ca2+ recording techniques use high K+ or field stimulation and dissociated neurons. To compare findings in intact dorsal root ganglia, we used a method of simultaneous electrophysiologic and microfluorimetric recording. Methods Dissociated neurons were loaded by bath-applied Fura-2-AM and subjected to field stimulation. Alternatively, we adapted a technique in which neuronal somata of intact ganglia were loaded with Fura-2 through an intracellular microelectrode that provided simultaneous membrane potential recording during activation by action potentials (APs) conducted from attached dorsal roots. Results Field stimulation at levels necessary to activate neurons generated bath pH changes through electrolysis and failed to predictably drive neurons with AP trains. In the intact ganglion technique, single APs produced measurable Ca2+ transients that were fourfold larger in presumed nociceptive C-type neurons than in nonnociceptive A?-type neurons. Unitary Ca2+ transients summated during AP trains, forming transients with amplitudes that were highly dependent on stimulation frequency. Each neuron was tuned to a preferred frequency at which transient amplitude was maximal. Transients predominantly exhibited monoexponential recovery and had sustained plateaus during recovery only with trains of more than 100 APs. Nerve injury decreased Ca2+ transients in C-type neurons, but increased transients in A?-type neurons. Conclusions Refined observation of Ca2+ signaling is possible through natural activation by conducted APs in undissociated sensory neurons and reveals features distinct to neuronal types and injury state. PMID:20526180

Gemes, Geza; Rigaud, Marcel; Koopmeiners, Andrew S.; Poroli, Mark J.; Zoga, Vasiliki; Hogan, Quinn H.

2013-01-01

297

Basal Septal Hypertrophy  

PubMed Central

A significant clinical problem is patients presenting with exercise-limiting dyspnoea, sometimes with associated chest pain, in the absence of detectable left ventricular (LV) systolic dysfunction, coronary artery disease, or lung disease. Often the patients are older, female, and have isolated basal septal hypertrophy (BSH), frequently on a background of mild hypertension. The topic of breathlessness in patients with clinical heart failure, but who have a normal ejection fraction (HFNEF) has attracted significant controversy over the past few years. This review aims to analyse the literature on BSH, identify the possible associations between BSH and HFNEF, and consequently explore possible pathophysiological mechanisms whereby clinical symptoms are experienced.

Kelshiker, Mihir A.; Mayet, Jamil; Unsworth, Beth; Okonko, Darlington O.

2013-01-01

298

Synaptic dimorphism in Onychophoran cephalic ganglia.  

PubMed

The taxonomic location of the Onychophora has been controversial because of their phenotypic and genotypic characteristics, related to both annelids and arthropods. We analyzed the ultrastructure of the neurons and their synapses in the cephalic ganglion of a poorly known invertebrate, the velvet worm Peripatus sedgwicki, from the mountainous region of El Valle, Mrida, Venezuela. Cephalic ganglia were dissected, fixed and processed for transmission electron microscopy. The animal has a high degree of neurobiological development, as evidenced by the presence of asymmetric (excitatory) and symmetric (inhibitory) synapses, as well as the existence of glial cell processes in a wide neuropile zone. The postsynaptic terminals were seen to contain subsynaptic cisterns formed by membranes of smooth endoplasmic reticulum beneath the postsynaptic density, whereas the presynaptic terminal showed numerous electron transparent synaptic vesicles. From the neurophylogenetic perspectives, the ultrastructural characteristics of the central nervous tissue of the Onychophora show important evolutionary acquirements, such as the presence of both excitatory and inhibitory synapses, indicating functional synaptic transmission, and the appearance of mature glial cells. PMID:18457135

Pea-Contreras, Z; Mendoza-Briceo, R V; Miranda-Contreras, L; Palacios-Pr, E L

2007-03-01

299

682 Diffusion Spectrum Imaging of White Matter Abnormalities in Fronto-Striato-Thalamic Circuit in Obsessive-Compulsive Disorder  

Microsoft Academic Search

Introduction Obsessive-Compulsive Disorder (OCD) is an anxiety disorder with a prevalence rate of 2% to 3% of the adult population. The clinical manifestations include persistent, intrusive thought and rituals or compulsions. To date, data from different lines of studies including neuronanatomical, neurosurgical, neuroparmacological and neruoimaging has provided important evidence implicating that the basal ganglia and by extension the striatal-thalamic and

C. H. Chiu

300

Hyperpolarizing `?2'-adrenoceptors in rat sympathetic ganglia  

PubMed Central

1 Receptors mediating catecholamine-induced hyperpolarization of isolated superior cervical sympathetic ganglia of the rat have been characterized by means of an extracellular recording method. 2 (-)-Noradrenaline (EC50, 1.7 0.6 ?M) produced an immediate low-amplitude (< 400 ?V) hyperpolarization. The hyperpolarization was increased on removal of external Ca2+ or on reduction of external K+ from 6 to 2 mM. Hyperpolarization was unaffected by changing the temperature from 25 to 37C. 3 Hyperpolarization was also produced by the following agonists (potencies relative to (-)-noradrenaline): (-)-noradrenaline 1; ()-isoprenaline 0.41; (-)-phenylephrine 0.40; (+)-noradrenaline 0.13; 2-amino-6,7-dihydroxy tetrahydronaphthalene (ADTN) 0.25; dopamine 0.1; methoxamine 0.012; amidephrine 0.0015. 4 Responses were antagonized by phentolamine (1 ?M) but not by ()-propranolol (1 ?M), haloperidol (10 ?M) or ?-flupenthixol (1 ?M). This suggested that hyperpolarization was mediated solely through ?-receptor stimulation not through stimulation of ?-receptors or dopamine-receptors. 5 Dose-ratio shifts produced by phentolamine varied with different agonists. The shift increased in inverse proportion to the ability of the agonists to inhibit [3H]-(-)-noradrenaline uptake, suggesting that uptake of agonists limited the dose-ratio shift. Cocaine and nortriptyline reduced catecholamine-induced hyperpolarization in concentrations (10 ?M and 1 ?M respectively) necessary to inhibit [3H]-(-)-noradrenaline uptake. 6 Clonidine (0.01 to 1 ?M), oxymetazoline (0.01 to 1 ?M) and ergometrine (0.1 to 10 ?M) produced a persistent, low-amplitude hyperpolarization, as though they were partial agonists. Responses to the agonists were blocked by yohimbine (1 ?M) but not be prazosin (1 ?M). 7 It is concluded that the adrenergic cell bodies in the ganglion were hyperpolarized through activation of the same type of ?-receptor (`?2-receptors') as those present at adrenergic nerve terminals. PMID:218668

Brown, D.A.; Caulfield, M.P.

1979-01-01

301

Journal of Abnormal Psychology  

Microsoft Academic Search

This article is reprinted from the Journal of Abnormal Psychology, 1965, 70, 1. The Journal of Abnormal Psychology will give priority to articles on problems related to abnormal behavior, broadly defined. The Journal's interests thus include the following: (a) psychopathology--its development or acquisition, its treatment or remission, and its symptomatology and course; (b) normal processes in abnormal individuals; (c) pathological

Howard F. Hunt; William N. Thetford

1965-01-01

302

Basal Twinning of Hematite  

NASA Astrophysics Data System (ADS)

When two crystals share a plane, there is a twinning composition plane. The result is an intergrowth of two separate crystals in a symmetrical manner. Crystallographers classify twinned crystals by a number of twin laws. These twin laws are specific to the crystal system. The type of twinning can be a diagnostic tool in mineral identification and characterization. Many twin laws cannot be recognized in ordinary optical analysis. So, the advent of diffraction techniques to describe punctual crystallographic orientation facilitated the identification of many twinned crystals in rocks. Samples containing hematite of the Quadriltero Ferrfero, Minas Gerais, Brazil, were analyzed by EBSD technique. Crystallographic orientation data were obtained from automatically indexed EBSD patterns collected on a JEOL JSM-5510. EBSD analysis was carried out on thin sections cut perpendicular to the foliation (XZ plane) and parallel to the stretching lineation (X-direction). Thin sections were polished before EBSD analysis. EBSD patterns were indexed using CHANNEL 5 software from HKL Technology, Oxford Instruments. The resulting data are presented in form of pole figures (upper hemisphere, equal angle, stereographic projection) and of colour-coded maps using Coincidence Site Lattice (? 3) and Twin Boundaries Components. Through electron backscatter diffraction analysis of hematite grains was possible to detect twin boundaries similar to Dauphin twinning in quartz that is not described for hematite. Dauphin twinning in trigonal ?-quartz consists of a 60 rotation around the c-axis resulting in a reversal of the crystallographic positive and negative forms (Frondel 1962). As both minerals show similar symmetry, the same mechanism can be described for hematite in this analysis. The basal twinning of hematite developed pervasively during the incipient stage of deformation. This paper investigates the relationships between this kind of twinning, deformation conditions and microstructural modifications in hematite grains. The results show that the presence of twins exerts an important role in the distribution of the intracrystalline plastic deformation in hematite, as well as in the activation of different sets of slip systems. We estimate that basal twin bands can be preferred sites for dynamic recrystallization.

Gonalves, Fbio; Lagoeiro, Leonardo; Barbosa, Paola

2013-04-01

303

Behavioral, Pharmacological, and Immunological Abnormalities after Streptococcal Exposure: A Novel Rat Model of Sydenham Chorea and Related Neuropsychiatric Disorders  

PubMed Central

Group A streptococcal (GAS) infections and autoimmunity are associated with the onset of a spectrum of neuropsychiatric disorders in children, with the prototypical disorder being Sydenham chorea (SC). Our aim was to develop an animal model that resembled the behavioral, pharmacological, and immunological abnormalities of SC and other streptococcal-related neuropsychiatric disorders. Male Lewis rats exposed to GAS antigen exhibited motor symptoms (impaired food manipulation and beam walking) and compulsive behavior (increased induced-grooming). These symptoms were alleviated by the D2 blocker haloperidol and the selective serotonin reuptake inhibitor paroxetine, respectively, drugs that are used to treat motor symptoms and compulsions in streptococcal-related neuropsychiatric disorders. Streptococcal exposure resulted in antibody deposition in the striatum, thalamus, and frontal cortex, and concomitant alterations in dopamine and glutamate levels in cortex and basal ganglia, consistent with the known pathophysiology of SC and related neuropsychiatric disorders. Autoantibodies (IgG) of GAS rats reacted with tubulin and caused elevated calcium/calmodulin-dependent protein kinase II signaling in SK-N-SH neuronal cells, as previously found with sera from SC and related neuropsychiatric disorders. Our new animal model translates directly to human disease and led us to discover autoantibodies targeted against dopamine D1 and D2 receptors in the rat model as well as in SC and other streptococcal-related neuropsychiatric disorders. PMID:22534626

Brimberg, Lior; Benhar, Itai; Mascaro-Blanco, Adita; Alvarez, Kathy; Lotan, Dafna; Winter, Christine; Klein, Julia; Moses, Allon E; Somnier, Finn E; Leckman, James F; Swedo, Susan E; Cunningham, Madeleine W; Joel, Daphna

2012-01-01

304

Shape abnormalities of subcortical and ventricular structures in mild cognitive impairment and Alzheimer's disease: detecting, quantifying, and predicting.  

PubMed

This article assesses the feasibility of using shape information to detect and quantify the subcortical and ventricular structural changes in mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients. We first demonstrate structural shape abnormalities in MCI and AD as compared with healthy controls (HC). Exploring the development to AD, we then divide the MCI participants into two subgroups based on longitudinal clinical information: (1) MCI patients who remained stable; (2) MCI patients who converted to AD over time. We focus on seven structures (amygdala, hippocampus, thalamus, caudate, putamen, globus pallidus, and lateral ventricles) in 754 MR scans (210 HC, 369 MCI of which 151 converted to AD over time, and 175 AD). The hippocampus and amygdala were further subsegmented based on high field 0.8 mm isotropic 7.0T scans for finer exploration. For MCI and AD, prominent ventricular expansions were detected and we found that these patients had strongest hippocampal atrophy occurring at CA1 and strongest amygdala atrophy at the basolateral complex. Mild atrophy in basal ganglia structures was also detected in MCI and AD. Stronger atrophy in the amygdala and hippocampus, and greater expansion in ventricles was observed in MCI converters, relative to those MCI who remained stable. Furthermore, we performed principal component analysis on a linear shape space of each structure. A subsequent linear discriminant analysis on the principal component values of hippocampus, amygdala, and ventricle leads to correct classification of 88% HC subjects and 86% AD subjects. PMID:24443091

Tang, Xiaoying; Holland, Dominic; Dale, Anders M; Younes, Laurent; Miller, Michael I

2014-08-01

305

Giant adenoid basal cell carcinoma.  

PubMed

The giant adenoid basal cell carcinoma is an unusual skin tumor that has aggressive biological behavior and has been reported to exhibit geometric growth, deep invasion, and metastasis. A case of giant adenoid basal cell carcinoma is presented, with recommendations for diagnosis and treatment. PMID:8060083

Herring, S M

1994-05-01

306

Polar basal melting on Mars  

NASA Astrophysics Data System (ADS)

The potential importance of basal melting on Mars is illustrated through the discussion of four examples: (1) the origin of the major polar reentrants, (2) the removal and storage of an ancient Martian ice sheet, (3) the mass balance of the polar terrains, and (4) the possibility of basal melting at temperate latitudes. This analysis suggests that the process of basal melting may play a key role in understanding the evolution of the Martian polar terrains and the long-term climatic behavior of water on Mars.

Clifford, S. M.

1987-08-01

307

Congenital and Developmental Abnormalities  

Microsoft Academic Search

Congenital and developmental abnormalities influencing life are rare. They mainly consist of pectus deformities, sternal fusion\\u000a abnormalities and clavicular pseudoarthrosis. The most life-threatening abnormality is cleft sternum which may leave the heart\\u000a and great vessels unprotected.

Anne Grethe Jurik

308

Measuring Abnormal Bond Performance  

Microsoft Academic Search

We analyze the empirical power and specification of test statistics designed to detect abnormal bond returns in corporate event studies, using monthly and daily data. We find that test statistics based on frequently used methods of calculating abnormal monthly bond returns are biased. Most methods implemented in monthly data also lack power to detect abnormal returns. We also consider unique

Hendrik Bessembinder; Kathleen M. Kahle; William F. Maxwell; Danielle Xu

2009-01-01

309

Evidence for Glutamate as a Neuroglial Transmitter within Sensory Ganglia  

PubMed Central

This study examines key elements of glutamatergic transmission within sensory ganglia of the rat. We show that the soma of primary sensory neurons release glutamate when depolarized. Using acute dissociated mixed neuronal/glia cultures of dorsal root ganglia (DRG) or trigeminal ganglia and a colorimetric assay, we show that when glutamate uptake by satellite glial cells (SGCs) is inhibited, KCl stimulation leads to simultaneous increase of glutamate in the culture medium. With calcium imaging we see that the soma of primary sensory neurons and SGCs respond to AMPA, NMDA, kainate and mGluR agonists, and selective antagonists block this response. Using whole cell patch-clamp technique, inward currents were recorded from small diameter (<30 m) DRG neurons from intact DRGs (ex-vivo whole ganglion preparation) in response to local application of the above glutamate receptor agonists. Following a chronic constriction injury (CCI) of either the inferior orbital nerve or the sciatic nerve, glutamate expression increases in the trigeminal ganglia and DRG respectively. This increase occurs in neurons of all diameters and is present in the somata of neurons with injured axons as well as in somata of neighboring uninjured neurons. These data provides additional evidence that glutamate can be released within the sensory ganglion, and that the somata of primary sensory neurons as well as SGCs express functional glutamate receptors at their surface. These findings, together with our previous gene knockdown data, suggest that glutamatergic transmission within the ganglion could impact nociceptive threshold. PMID:23844184

Kung, Ling-Hsuan; Gong, Kerui; Adedoyin, Mary; Ng, Johnson; Bhargava, Aditi; Ohara, Peter T.; Jasmin, Luc

2013-01-01

310

Abnormal Myelin and Axonal Integrity in Recently Diagnosed Patients with Obstructive Sleep Apnea  

PubMed Central

Study Objectives: Patients with obstructive sleep apnea (OSA) show significant white matter injury; whether that injury represents myelin or axonal damage is unclear. The objective was to examine myelin and axonal changes in patients with newly diagnosed OSA over control subjects. Design: Cross-sectional study. Setting: University-based medical center. Participants: Twenty-three newly-diagnosed, treatment-nave OSA and 23 age- and sex-matched control subjects. Interventions: None. Measurements and Results: Radial and axial diffusivity maps, calculated from diffusion tensor imaging data (3.0 Tesla MRI scanner), indicating diffusion perpendicular (myelin status) or parallel (axonal status) to fibers, respectively, were normalized, smoothed, and compared between groups (analysis of covariance; covariate: age). Global brain radial and axial diffusivity values, and global brain volume with myelin and axonal changes were determined, and region-of-interest analyses performed in areas of significant differences between groups based on voxel-based procedures. Global radial and axial diffusivity values were significantly reduced in OSA versus control subjects (radial, P = 0.004; axial, P = 0.019), with radial (myelin) diffusivity reduced more than axial (axonal), and more left-sided reduction for both measures. Localized declines for myelin and axonal measures appeared in the dorsal and ventral medulla, cerebellar cortex and deep nuclei, basal ganglia, hippocampus, amygdala, corpus callosum, insula, cingulate and medial frontal cortices, and other cortical areas (P < 0.005), all regions mediating functions affected in OSA. Conclusions: Fiber injury appears in critical medullary respiratory regulatory sites, as well as cognitive and autonomic control areas. Myelin is more affected in newly diagnosed OSA than axons, and primarily on the left side, possibly from the increased myelin sensitivity to hypoxia and asymmetric perfusion. Citation: Kumar R; Pham TT; Macey PM; Woo MA; Yan-Go FL; Harper RM. Abnormal myelin and axonal integrity in recently diagnosed patients with obstructive sleep apnea. SLEEP 2014;37(4):723-732. PMID:24899761

Kumar, Rajesh; Pham, Tiffany T.; Macey, Paul M.; Woo, Mary A.; Yan-Go, Frisca L.; Harper, Ronald M.

2014-01-01

311

Structural and functional abnormalities of the motor system in developmental stuttering  

PubMed Central

Summary Though stuttering is manifest in its motor characteristics, the cause of stuttering may not relate purely to impairments in the motor system as stuttering frequency is increased by linguistic factors, such as syntactic complexity and length of utterance, and decreased by changes in perception, such as masking or altering auditory feedback. Using functional and diffusion imaging, we examined brain structure and function in the motor and language areas in a group of young people who stutter. During speech production, irrespective of fluency or auditory feedback, the people who stuttered showed overactivity relative to controls in the anterior insula, cerebellum and midbrain bilaterally and underactivity in the ventral premotor, Rolandic opercular and sensorimotor cortex bilaterally and Heschls gyrus on the left. These results are consistent with a recent meta-analysis of functional imaging studies in developmental stuttering. Two additional findings emerged from our study. First, we found overactivity in the midbrain, which was at the level of the substantia nigra and extended to the pedunculopontine nucleus, red nucleus and subthalamic nucleus. This overactivity is consistent with suggestions in previous studies of abnormal function of the basal ganglia or excessive dopamine in people who stutter. Second, we found underactivity of the cortical motor and premotor areas associated with articulation and speech production. Analysis of the diffusion data revealed that the integrity of the white matter underlying the underactive areas in ventral premotor cortex was reduced in people who stutter. The white matter tracts in this area via connections with posterior superior temporal and inferior parietal cortex provide a substrate for the integration of articulatory planning and sensory feedback, and via connections with primary motor cortex, a substrate for execution of articulatory movements. Our data support the conclusion that stuttering is a disorder related primarily to disruption in the cortical and subcortical neural systems supporting the selection, initiation and execution of motor sequences necessary for fluent speech production. PMID:17928317

Watkins, Kate E.; Smith, Stephen M.; Davis, Steve; Howell, Peter

2007-01-01

312

Nevoid basal cell carcinoma syndrome (Gorlin syndrome)  

PubMed Central

Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, is a hereditary condition characterized by a wide range of developmental abnormalities and a predisposition to neoplasms. The estimated prevalence varies from 1/57,000 to 1/256,000, with a male-to-female ratio of 1:1. Main clinical manifestations include multiple basal cell carcinomas (BCCs), odontogenic keratocysts of the jaws, hyperkeratosis of palms and soles, skeletal abnormalities, intracranial ectopic calcifications, and facial dysmorphism (macrocephaly, cleft lip/palate and severe eye anomalies). Intellectual deficit is present in up to 5% of cases. BCCs (varying clinically from flesh-colored papules to ulcerating plaques and in diameter from 1 to 10 mm) are most commonly located on the face, back and chest. The number of BBCs varies from a few to several thousand. Recurrent jaw cysts occur in 90% of patients. Skeletal abnormalities (affecting the shape of the ribs, vertebral column bones, and the skull) are frequent. Ocular, genitourinary and cardiovascular disorders may occur. About 510% of NBCCS patients develop the brain malignancy medulloblastoma, which may be a potential cause of early death. NBCCS is caused by mutations in the PTCH1 gene and is transmitted as an autosomal dominant trait with complete penetrance and variable expressivity. Clinical diagnosis relies on specific criteria. Gene mutation analysis confirms the diagnosis. Genetic counseling is mandatory. Antenatal diagnosis is feasible by means of ultrasound scans and analysis of DNA extracted from fetal cells (obtained by amniocentesis or chorionic villus sampling). Main differential diagnoses include Bazex syndrome, trichoepithelioma papulosum multiplex and Torre's syndrome (Muir-Torre's syndrome). Management requires a multidisciplinary approach. Keratocysts are treated by surgical removal. Surgery for BBCs is indicated when the number of lesions is limited; other treatments include laser ablation, photodynamic therapy and topical chemotherapy. Radiotherapy should be avoided. Vitamin A analogs may play a preventive role against development of new BCCs. Life expectancy in NBCCS is not significantly altered but morbidity from complications can be substantial. Regular follow-up by a multi-specialist team (dermatologist, neurologist and odontologist) should be offered. Patients with NBCCS should strictly avoid an excessive sun exposure. PMID:19032739

Lo Muzio, Lorenzo

2008-01-01

313

Basal Ganglia Accumulation and Motor Assessment Following Manganese Chloride Exposure in the C57BL\\/6 Mouse  

Microsoft Academic Search

Equivocal clinical evidence for involvement of manganese in development of Parkinson's disease necessitates experimental studies on this issue. The aged, 1-methyl-4-phenyl-1,2,3,6-tetrahyropyridinetreated C57BL\\/6 mouse is one of the most common models for Parkinson's disease. However, there is little information on brain bioaccumulation of manganese, and little or no information on clinical\\/behavioral manifestations of manganese neurotoxicity, in this strain. Male C57BL\\/6 retired

Celia A. Dodd; Daniel L. Ward; Bradley G. Klein

2005-01-01

314

A novel mutation in TTC19 associated with isolated complex III deficiency, cerebellar hypoplasia, and bilateral basal ganglia lesions  

PubMed Central

Isolated complex III (cIII) deficiency is a rare biochemical finding in mitochondrial disorders, mainly associated with mutations in mitochondrial DNA MTCYB gene, encoding cytochrome b, or in assembly factor genes (BCS1L, TTC19, UQCC2, and LYRM7), whereas mutations in nuclear genes encoding cIII structural subunits are extremely infrequent. We report here a patient, a 9 year old female born from first cousin related parents, with normal development till 18 months when she showed unsteady gait with frequent falling down, cognitive, and speech worsening. Her course deteriorated progressively. Brain MRI showed cerebellar vermis hypoplasia and bilateral lentiform nucleus high signal lesions. Now she is bed ridden with tetraparesis and severely impaired cognitive and language functions. Biochemical analysis revealed isolated cIII deficiency in muscle, and impaired respiration in fibroblasts. We identified a novel homozygous rearrangement in TTC19 (c.213_229dup), resulting in frameshift with creation of a premature termination codon (p.Gln77Argfs*30). Western blot analysis demonstrated the absence of TTC19 protein in patients fibroblasts, while Blue-Native Gel Electrophoresis analysis revealed the presence of cIII-specific assembly intermediates. Mutations in TTC19 have been rarely associated with mitochondrial disease to date, being described in about ten patients with heterogeneous clinical presentations, ranging from early onset encephalomyopathy to adult forms with cerebellar ataxia. Contrariwise, the biochemical defect was a common hallmark in TTC19 mutant patients, confirming the importance of TTC19 in cIII assembly/stability. Therefore, we suggest extending the TTC19 mutational screening to all patients with cIII deficiency, independently from their phenotypes.

Melchionda, Laura; Damseh, Nadirah S.; Abu Libdeh, Bassam Y.; Nasca, Alessia; Elpeleg, Orly; Zanolini, Alice; Ghezzi, Daniele

2014-01-01

315

Chemoarchitecture and afferent connections of the "olfactostriatum": a specialized vomeronasal structure within the basal ganglia of snakes.  

PubMed

The olfactostriatum, a portion of the striatal complex of snakes, is the major tertiary vomeronasal structure in the ophidian brain, receiving substantial afferents from the nucleus sphericus, the primary target of accessory olfactory bulb efferents. In the present study, we have characterized the olfactostriatum of garter snakes (Thamnophis sirtalis) on the basis of chemoarchitecture (distribution of serotonin, neuropeptide Y and tyrosine hydroxylase) and hodology (afferent connections). The olfactostriatum is densely immunoreactive for serotonin and neuropeptide Y and shows moderate-to-weak immunoreactivity for tyrosine hydroxylase. In addition to afferents from the nucleus sphericus, the olfactostriatum receives inputs from the dorsal and lateral cortices, nucleus of the accessory olfactory tract, external and dorsolateral amygdalae, dorsomedial thalamic nucleus, ventral tegmental area and raphe nuclei. Double labeling experiments demonstrated that the distribution of serotonin and neuropeptide Y in this area almost completely overlaps the terminal field of projections from the nucleus sphericus. Also, serotonergic and dopaminergic innervation of the olfactostriatum likely arise, respectively, from the raphe nuclei and the ventral tegmental area, whereas local circuit neurons originate the neuropeptide Y immunoreactivity. These results indicate that the olfactostriatum of snakes could be a portion of the nucleus accumbens, with features characteristic of the accumbens shell, devoted to processing vomeronasal information. Comparative data suggest that a similar structure is present in the ventral striatum of amphibians and mammals. PMID:15589701

Martinez-Marcos, Alino; Ubeda-Baon, Isabel; Lanuza, Enrique; Halpern, Mimi

2005-01-01

316

Age-related iron deposition in the basal ganglia of controls and Alzheimer disease patients quantified using susceptibility weighted imaging.  

PubMed

This study aimed to investigate age-related iron deposition changes in healthy subjects and Alzheimer disease patients using susceptibility weighted imaging. The study recruited 182 people, including 143 healthy volunteers and 39 Alzheimer disease patients. All underwent conventional magnetic resonance imaging and susceptibility weighted imaging sequences. The groups were divided according to age. Phase images were used to investigate iron deposition in the bilateral head of the caudate nucleus, globus pallidus and putamen, and the angle radian value was calculated. We hypothesized that age-related iron deposition changes may be different between Alzheimer disease patients and controls of the same age, and that susceptibility weighted imaging would be a more sensitive method of iron deposition quantification. The results revealed that iron deposition in the globus pallidus increased with age, up to 40 years. In the head of the caudate nucleus, iron deposition peaked at 60 years. There was a general increasing trend with age in the putamen, up to 50-70 years old. There was significant difference between the control and Alzheimer disease groups in the bilateral globus pallidus in both the 60-70 and 70-80 year old group comparisons. In conclusion, iron deposition increased with age in the globus pallidus, the head of the caudate nucleus and putamen, reaching a plateau at different ages. Furthermore, comparisons between the control and Alzheimer disease group revealed that iron deposition changes were more easily detected in the globus pallidus. PMID:24820446

Wang, Dan; Li, Yan-Ying; Luo, Jian-Hua; Li, Yue-Hua

2014-01-01

317

Late onset familial dystonia: could mitochondrial deficits induce a diffuse lesioning process of the whole basal ganglia system?  

Microsoft Academic Search

BACKGROUNDStriatal necrosis has been related to various clinical syndromes, with acute or chronic progression, and juvenile or late occurrence, but the most common type is Leighs encephalopathy.METHODSBetween 1967 and 1995, six out of seven related patients with chronic familial dystonia were examined. MRIs were performed in four, between 1992-1994. The seven members, affected over three generations, were the father, three

D Caparros-Lefebvre; A Deste; H Petit

1997-01-01

318

Altered frontocortical, cerebellar, and basal ganglia activity in adjuvant-treated breast cancer survivors 510years after chemotherapy  

Microsoft Academic Search

Purpose To explore the relationship of regional cerebral blood flow and metabolism with cognitive function and past exposure to chemotherapy\\u000a for breast cancer.\\u000a \\u000a \\u000a Patients and methods Subjects treated for breast cancer with adjuvant chemotherapy remotely (510years previously) were studied with neuropsychologic\\u000a testing and positron emission tomography (PET), and were compared with control subjects who had never received chemotherapy.\\u000a [O-15] water

Daniel H. S. Silverman; Christine J. Dy; Steven A. Castellon; Jasmine Lai; Betty S. Pio; Laura Abraham; Kari Waddell; Laura Petersen; Michael E. Phelps; Patricia A. Ganz

2007-01-01

319

Oculomotor learning revisited: a model of reinforcement learning in the basal ganglia incorporating an efference copy of motor actions  

E-print Network

In its simplest formulation, reinforcement learning is based on the idea that if an action taken in a particular context is followed by a favorable outcome, then, in the same context, the tendency to produce that action ...

Fee, Michale S.

320

Functional deficits in basal ganglia of children with attention-deficit\\/hyperactivity disorder shown with functional magnetic resonance imaging relaxometry  

Microsoft Academic Search

Attention-deficit\\/hyperactivity disorder is a highly heritable and prevalent neuropsychiatric disorder estimated to affect 6% of school-age children. Its clinical hallmarks are inattention, hyperactivity and impulsivity, which often respond substantially to treatment with methylphenidate or dextroamphetamine. Etiological theories suggest a deficit in corticostriatal circuits, particularly those components modulated by dopamine. We developed a new functional magnetic resonance imaging procedure (T2 relaxometry)

Carl M. Anderson; Ann Polcari; Carol A. Glod; Luis C. Maas; Perry F. Renshaw; Martin H. Teicher

2000-01-01

321

Cooperation of the basal ganglia, cerebellum, sensory cerebrum and hippocampus: possible implications for cognition, consciousness, intelligence and creativity  

Microsoft Academic Search

It is suggested that the anatomical structures which mediate consciousness evolved as decisive embellishments to a (non-conscious) design strategy present even in the simplest unicellular organisms. Consciousness is thus not the pinnacle of a hierarchy whose base is the primitive reflex, because reflexes require a nervous system, which the single-celled creature does not possess. By postulating that consciousness is intimately

Rodney M. J. Cotterill

2001-01-01

322

The structure of tonic flexor motoneurons in crayfish abdominal ganglia  

Microsoft Academic Search

1.The tonic flexor motoneurons were filled with cobalt dye via the cut ends of their axons. All six physiologically defined cells were identified anatomically (Figs. 24).2.The cell somata are widely scattered in the ventral rind of the ganglia; three cells have ipsilateral and three cells have contralateral somata in reference to their axons; cells with contralateral somata tend to be

Jeffrey J. Wine; Jay E. Mittenthal; Donald Kennedy

1974-01-01

323

Facial nerve parasympathetic preganglionic afferents to the accessory otic ganglia by way of the chorda tympani nerve in the cat  

Microsoft Academic Search

The distribution of accessory otic ganglia and connections between the ganglia and the chorda tympani nerve were investigated\\u000a in the cat in order to determine the parasympathetic preganglionic facial nerve afferents to the otic ganglia using whole\\u000a mount acetylthiocholinesterase (WATChE) histochemistry. The otic ganglia consist of a sigle main prominent ganglion and many\\u000a small accessory ganglia lying on a plexus

Satoshi Kuchiiwa; T. Kuchiiwa; Satoru Nonaka; Shiro Nakagawa

1998-01-01

324

Comprehensive RNA-Seq Expression Analysis of Sensory Ganglia with a Focus on Ion Channels and GPCRs in Trigeminal Ganglia  

PubMed Central

The specific functions of sensory systems depend on the tissue-specific expression of genes that code for molecular sensor proteins that are necessary for stimulus detection and membrane signaling. Using the Next Generation Sequencing technique (RNA-Seq), we analyzed the complete transcriptome of the trigeminal ganglia (TG) and dorsal root ganglia (DRG) of adult mice. Focusing on genes with an expression level higher than 1 FPKM (fragments per kilobase of transcript per million mapped reads), we detected the expression of 12984 genes in the TG and 13195 in the DRG. To analyze the specific gene expression patterns of the peripheral neuronal tissues, we compared their gene expression profiles with that of the liver, brain, olfactory epithelium, and skeletal muscle. The transcriptome data of the TG and DRG were scanned for virtually all known G-protein-coupled receptors (GPCRs) as well as for ion channels. The expression profile was ranked with regard to the level and specificity for the TG. In total, we detected 106 non-olfactory GPCRs and 33 ion channels that had not been previously described as expressed in the TG. To validate the RNA-Seq data, in situ hybridization experiments were performed for several of the newly detected transcripts. To identify differences in expression profiles between the sensory ganglia, the RNA-Seq data of the TG and DRG were compared. Among the differentially expressed genes (> 1 FPKM), 65 and 117 were expressed at least 10-fold higher in the TG and DRG, respectively. Our transcriptome analysis allows a comprehensive overview of all ion channels and G protein-coupled receptors that are expressed in trigeminal ganglia and provides additional approaches for the investigation of trigeminal sensing as well as for the physiological and pathophysiological mechanisms of pain. PMID:24260241

Manteniotis, Stavros; Lehmann, Ramona; Flegel, Caroline; Vogel, Felix; Hofreuter, Adrian; Schreiner, Benjamin S. P.; Altmuller, Janine; Becker, Christian; Schobel, Nicole; Hatt, Hanns; Gisselmann, Gunter

2013-01-01

325

Abnormal haemoglobins: detection & characterization  

PubMed Central

Haemoglobin (Hb) abnormalities though quite frequent, are generally detected in populations during surveys and programmes run for prevention of Hb disorders. Several methods are now available for detection of Hb abnormalities. In this review, the following are discussed: (i) the methods used for characterization of haemoglobin disorders; (ii) the problems linked to diagnosis of thalassaemic trait; (iii) the strategy for detection of common Hb variants; and (iv) the difficulties in identification of rare variants. The differences between developing and industrialized countries for the strategies employed in the diagnosis of abnormal haemoglobins are considered. We mention the limits and pitfalls for each approach and the necessity to characterize the abnormalities using at least two different methods. The recommended strategy is to use a combination of cation-exchange high performance chromatography (CE-HPLC), capillary electrophoresis (CE) and when possible isoelectric focusing (IEF). Difficult cases may demand further investigations requiring specialized protein and/or molecular biology techniques. PMID:22089618

Wajcman, Henri; Moradkhani, Kamran

2011-01-01

326

Tooth - abnormal colors  

MedlinePLUS

... Questions may involve: When the abnormal coloration began Foods you have been eating Medications you are taking Personal and family health history Exposure to fluoride Oral care habits Other symptoms ...

327

"Jeopardy" in Abnormal Psychology.  

ERIC Educational Resources Information Center

Describes the use of the board game, Jeopardy, in a college level abnormal psychology course. Finds increased student interaction and improved application of information. Reports generally favorable student evaluation of the technique. (CFR)

Keutzer, Carolin S.

1993-01-01

328

A putative hyperglycemic factor from the cerebral ganglia of Otala lactea (Mollusca: Pulmonata)  

Microsoft Academic Search

Mantle tissue pieces from adult Otala lactea continuously synthesized glycogen over a 72-h incubation period. Acid-saline extract of the cerebral ganglia inhibited glycogen\\u000a synthesis by mantle tissue in vitro. This effect was dose-dependent. The glycogen reduction factor from the cerebral ganglia\\u000a was heat stable, protease sensitive, and relatively hydrophobic. The cerebral ganglia extract also stimulated mantle glycogen\\u000a phosphorylase in vitro

A. M. Abdraba; A. S. M. Saleuddin

2000-01-01

329

Basal cell nevus syndrome - plantar pits (image)  

MedlinePLUS

... Skin manifestations include pits in the palms and soles, and numerous basal cell carcinomas (skin cancers). This ... close-up of the pits found on the sole of the foot of an individual with basal ...

330

Home treatment of basal cell carcinoma.  

PubMed

The sap of the plant Euphorbia peplus is not uncommonly used as a home treatment for warts and basal cell carcinomas. This report documents its successful use on a biopsy-proven basal cell carcinoma. PMID:979751

Weedon, D; Chick, J

1976-06-12

331

Expression of varicella-zoster virus and herpes simplex virus in normal human trigeminal ganglia  

SciTech Connect

Lysates of radiolabeled explants from four human trigeminal ganglia were immunoprecipitated with antibodies to varicella-zoster virus (VZV) and to herpes simplex virus. Both herpes simplex virus- and VZV-specific proteins were detected in lysates of all four ganglia. Absence of reactivity in ganglion explants with monoclonal antibodies suggested that herpes simplex virus and VZV were not reactivated during the culture period. In situ hybridization studies demonstrated the presence of RNA transcripts from the VZV immediate early gene 63. This approach to the detection of herpes simplex virus and VZV expression in human ganglia should facilitate analysis of viral RNA and proteins in human sensory ganglia.

Vafai, A.; Wellish, M.; Devlin, M.; Gilden, D.H. (Univ. of Colorado School of Medicine, Denver (USA)); Murray, R.S. (Univ. of Colorado School of Medicine, Denver (USA) Veterans Administration Medical Center, Denver, CO (USA))

1988-04-01

332

EmergencyEmergency and Abnormal Situationsand Abnormal Situations  

E-print Network

SituationsAbnormal Situations Neil Johnston Aerospace Psychology Research Group Trinity College DublinEmergencyEmergency and Abnormal Situationsand Abnormal Situations in Aviation Symposiumin Aviation Symposium Santa Clara, June 2003 #12;Responding toResponding to Emergencies andEmergencies and Abnormal

333

Models of Abnormal Scarring  

PubMed Central

Keloids and hypertrophic scars are thick, raised dermal scars, caused by derailing of the normal scarring process. Extensive research on such abnormal scarring has been done; however, these being refractory disorders specific to humans, it has been difficult to establish a universal animal model. A wide variety of animal models have been used. These include the athymic mouse, rats, rabbits, and pigs. Although these models have provided valuable insight into abnormal scarring, there is currently still no ideal model. This paper reviews the models that have been developed. PMID:24078916

Seo, Bommie F.; Lee, Jun Yong; Jung, Sung-No

2013-01-01

334

Monitoring Temperature and Fan Speed Using Ganglia and Winbond Chips  

SciTech Connect

Effective monitoring is essential to keep a large group of machines, like the ones at Stanford Linear Accelerator Center (SLAC), up and running. SLAC currently uses Ganglia Monitoring System to observe about 2000 machines, analyzing metrics like CPU usage and I/O rate. However, metrics essential to machine hardware health, such as temperature and fan speed, are not being monitored. Many machines have a Winbond w83782d chip which monitors three temperatures, two of which come from dual CPUs, and returns the information when the sensor command is invoked. Ganglia also provides a feature, gmetric, that allows the users to monitor their own metrics and incorporate them into the monitoring system. The programming language Perl is chosen to implement a script that invokes the sensors command, extracts the temperature and fan speed information, and calls gmetric with the appropriate arguments. Two machines were used to test the script; the two CPUs on each machine run at about 65 Celsius, which is well within the operating temperature range (The maximum safe temperature range is 77-82 Celsius for the Pentium III processors being used). Installing the script on all machines with a Winbond w83782d chip allows the SLAC Scientific Computing and Computing Services group (SCCS) to better evaluate current cooling methods.

McCaffrey, Cattie; /SLAC

2006-09-27

335

Cytotoxic responses of selected insecticides in chick ganglia cultures.  

PubMed Central

Various agricultural chemicals, e.g. pesticides, are known to cause different toxic effects in man and animals. Some of these produce responses involving the nervous tissue. Total of 52 such chemicals, representing organophosphates, carbamates and other miscellaneous insecticides were evaluated to determine their relative cytotoxic effects in avian dorsal root ganglia cultures. Many of these chemicals caused a slight stimulation of cellular growth at very low concentrations. At toxic concentrations, a dose-related but nonspecific inhibition of cell growth occurred. The cytotoxic changes included the decreased migration of cells from the culture implant, varicosities in and shortening of various cells and vacuolization and rounding of neuroglial cells. At high concentrations, pigmentary degeneration and complete abolition of cell growth were observed. The toxic effects were numerically scored in a random blind fashion and the concentrations of individual chemicals to produce a half maximal effect (IC50) in culture were determined from the dose-response curves. The IC50 values for various chemicals ranged from approximately 10(-6) M for compounds like methylparathion, diazinon, paraoxon and Vendex to greater than 10(-2) M for chlorpyriphos and methylchlorpyriphos. No significant correlations of nerve fiber or glial cell cytotoxicity were apparent with other toxic or physico-chemical properties such as lethal dose in animals, cholinesterase inhibition, lipophilicity or water solubility of chemicals. Clinically neurotoxic and nonneurotoxic compounds caused similar cytotoxic effects in ganglia cultures. Images Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:7272842

Sharma, R P; Obersteiner, E J

1981-01-01

336

Detection of Abnormal Hemoglobins.  

National Technical Information Service (NTIS)

An intensive literature survey was performed to review the methods and products used to detect, identify and/or quantitate abnormal or variant hemoglobins in human erythrocytes. The report consists of a bibliography (198 citations, 1968-1979) and a summar...

J. Atwater, B. E. Hindman, K. Joseph

1979-01-01

337

Abnormal Psychology Psychology 280  

E-print Network

psychopathology perspective to understand: 2.1. risk and protective factors influencing the etiology abnormal behavior in everyday life and we need to gain a better understanding of the etiology, social worker, therapist, etc.) directly rely on having extensive knowledge of psychopathology. #12

Liu, Taosheng

338

Behaviour of oil ganglia displaced by a surfactant solution in a porous medium  

E-print Network

L-97 Behaviour of oil ganglia displaced by a surfactant solution in a porous medium J. C. Moulu'importance relative des forces de viscosité et des forces capillaires. Abstract. 2014 The velocity of oil ganglia residual oil phase by water injection in a porous medium [1, 2]. These studies have demonstrated

Boyer, Edmond

339

MORPHOLOGY OF IDENTIFIED NEURONES IN THE BUCCAL GANGLIA OF LYMNAEA STAGNALIS  

Microsoft Academic Search

SUMMARY The morphology of seven types of identified neurones in buccal ganglia of Lymnaea was investigated by intracellular injection of Procion Yellow and retrograde injection of cobaJtous chloride into the nerve roots of the buccal ganglia. The results provided anatomical support for the electrophysiological findings that some cells are motoneurones for muscles of the buccal mass (type 4-group cells, types

P. R. BENJAMIN; R. M. ROSE; CAROLE T. SLADE

1979-01-01

340

Cholangiocyte Cilia and Basal Bodies  

Microsoft Academic Search

\\u000a Primary cilia are nonmotile, tubular organelles extending from the cell plasma membrane. They are important in maintaining\\u000a normal cell physiology and in many clinical disorders (i.e., cilia-related diseases or ciliopathies) associated with abnormalities\\u000a in ciliary structure and\\/or function.\\u000a \\u000a \\u000a In the intrahepatic bile ducts, primary cilia extend from the cholangiocyte apical plasma membrane into the ductal lumen.\\u000a Cholangiocyte cilia are sensory

Tatyana V. Masyuk; Anatoliy I. Masyuk; Nicholas F. LaRusso

341

Feline mammary basal-like adenocarcinomas: a potential model for human triple-negative breast cancer (TNBC) with basal-like subtype  

PubMed Central

Background Breast cancer is one of the leading causes of cancer deaths. Triple-negative breast cancer (TNBC), an immunophenotype defined by the absence of immunolabeling for estrogen receptor (ER), progesterone receptor (PR) and HER2 protein, has a highly aggressive behavior. A subpopulation of TNBCs exhibit a basal-like morphology with immunohistochemical positivity for cytokeratins 5/6 (CK5/6) and/or epidermal growth factor receptor (EGFR), and have a high incidence of BRCA (breast cancer susceptibility) mutations. Feline mammary adenocarcinomas (FMAs) are highly malignant and share a similar basal-like subtype. The purpose of this study was to classify FMAs according to the current human classification of breast cancer that includes evaluation of ER, PR and HER2 status and expression of basal CK 5/6 and EGFR. Furthermore, we selected triple negative, basal-like FMAs to screen for BRCA mutations similar to those described in human TNBC. Methods Twenty four FMAs were classified according to the current human histologic breast cancer classification including immunohistochemistry (IHC) for ER, PR HER2, CK5/6 and EGFR. Genetic alteration and loss of heterozygosity of BRCA1 and BRCA2 genes were analyzed in triple negative, basal-like FMAs. Results IHC for ER, PR and HER2 identified 14 of the 24 (58%) FMAs as a triple negative. Furthermore, 11of these 14 (79%) triple negative FMAs had a basal-like subtype. However, no genetic abnormalities were detected in BRCA1 and BRCA2 by direct sequencing and loss of heterozygosity analysis. Conclusion FMAs are highly aggressive neoplasms that are commonly triple negative and exhibit a basal-like morphology. This is similar to human TNBC that are also commonly classified as a basal-like subtype. While sequencing of a select number of triple negative, basal-like FMAs and testing for loss of heterozygosity of BRCA1 and BRCA2 did not identify mutations similar to those described in human TNBC, further in-depth evaluation is required to elucidate a potential role of BRCA in the tumorigenesis of triple negative, basal-like FMAs. The strong similarities in clinical behavior, morphology and IHC phenotype suggest that triple negative, basal-like FMAs may be a suitable spontaneous animal model for studying novel therapeutic approaches against human basal-like TNBC. PMID:24004841

2013-01-01

342

Adequately address abnormal operations  

SciTech Connect

Abnormal situation management (ASM) is a safety issue, and safety long has been a top priority for companies in the chemical process industries (CPI). To investigate and identify root causes of abnormal operations and to pinpoint best practices for preventing these situations or at least handling them most effectively, the author formed a team and conducted surveys around the world, including the US, Canada, the United Kingdom, Europe, and Japan. The author visited a variety of facilities, including gas processing plants, oil refineries, a coker, ethylene plant, polyethylene units, steam-generating stations, as well as transportation and storage facilities. The team identified eight key issues: lack of management leadership; the significant role of human errors; inadequate design of the work environment; absence of procedures for dealing with abnormal operations (as opposed to emergencies); loss of valuable information from earlier minor incidents; the potential economic return; transferability of good ASM performance to other plants; and the importance of teamwork and job design. The paper looks at each of these in more detail, as well as what`s involved in assessing the ASM at a site.

Nimmo, I. [Honeywell Industrial Automation and Control, Phoenix, AZ (United States)

1995-09-01

343

Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.  

ERIC Educational Resources Information Center

Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.

Fernald, Charles D.

1980-01-01

344

Molecular analysis of neurogenic placode development in a basal ray-finned fish  

PubMed Central

Neurogenic placodes are transient, thickened patches of embryonic vertebrate head ectoderm that give rise to the paired peripheral sense organs and most neurons in cranial sensory ganglia. We present the first analysis of gene expression during neurogenic placode development in a basal actinopterygian (ray-finned fish), the North American paddlefish (Polyodon spathula). Pax3 expression in the profundal placode confirms its homology with the ophthalmic trigeminal placode of amniotes. We report the conservation of expression of Pax2 and Pax8 in the otic and/or epibranchial placodes, Phox2b in epibranchial placode-derived neurons, Sox3 during epibranchial and lateral line placode development, and NeuroD in developing cranial sensory ganglia. We identify Sox3 as a novel marker for developing fields of electrosensory ampullary organs and for ampullary organs themselves. Sox3 is also the first molecular marker for actinopterygian ampullary organs. This is consistent with, though does not prove, a lateral line placode origin for actinopterygian ampullary organs. PMID:21381180

Modrell, Melinda S.; Buckley, David; Baker, Clare V.H.

2014-01-01

345

Molecular analysis of neurogenic placode development in a basal ray-finned fish.  

PubMed

Neurogenic placodes are transient, thickened patches of embryonic vertebrate head ectoderm that give rise to the paired peripheral sense organs and most neurons in cranial sensory ganglia. We present the first analysis of gene expression during neurogenic placode development in a basal actinopterygian (ray-finned fish), the North American paddlefish (Polyodon spathula). Pax3 expression in the profundal placode confirms its homology with the ophthalmic trigeminal placode of amniotes. We report the conservation of expression of Pax2 and Pax8 in the otic and/or epibranchial placodes, Phox2b in epibranchial placode-derived neurons, Sox3 during epibranchial and lateral line placode development, and NeuroD in developing cranial sensory ganglia. We identify Sox3 as a novel marker for developing fields of electrosensory ampullary organs and for ampullary organs themselves. Sox3 is also the first molecular marker for actinopterygian ampullary organs. This is consistent with, though does not prove, a lateral line placode origin for actinopterygian ampullary organs. PMID:21381180

Modrell, Melinda S; Buckley, David; Baker, Clare V H

2011-04-01

346

Chondrogenic and Gliogenic Subpopulations of Neural Crest Play Distinct Roles during the Assembly of Epibranchial Ganglia  

PubMed Central

In vertebrates, the sensory neurons of the epibranchial (EB) ganglia transmit somatosensory signals from the periphery to the CNS. These ganglia are formed during embryogenesis by the convergence and condensation of two distinct populations of precursors: placode-derived neuroblasts and neural crest- (NC) derived glial precursors. In addition to the gliogenic crest, chondrogenic NC migrates into the pharyngeal arches, which lie in close proximity to the EB placodes and ganglia. Here, we examine the respective roles of these two distinct NC-derived populations during development of the EB ganglia using zebrafish morphant and mutants that lack one or both of these NC populations. Our analyses of mutant and morphant zebrafish that exhibit deficiencies in chondrogenic NC at early stages reveal a distinct requirement for this NC subpopulation during early EB ganglion assembly and segmentation. Furthermore, restoration of wildtype chondrogenic NC in one of these mutants, prdm1a, is sufficient to restore ganglion formation, indicating a specific requirement of the chondrogenic NC for EB ganglia assembly. By contrast, analysis of the sox10 mutant, which lacks gliogenic NC, reveals that the initial assembly of ganglia is not affected. However, during later stages of development, EB ganglia are dispersed in the sox10 mutant, suggesting that glia are required to maintain normal EB ganglion morphology. These results highlight novel roles for two subpopulations of NC cells in the formation and maintenance of EB ganglia: chondrogenic NC promotes the early-stage formation of the developing EB ganglia while glial NC is required for the late-stage maintenance of ganglion morphology. PMID:21931719

Culbertson, Maya D.; Lewis, Zachary R.; Nechiporuk, Alexei V.

2011-01-01

347

Roentgenologic Abnormalities in Down's Syndrome.  

National Technical Information Service (NTIS)

Roentgenograms of 28 patients with Down's syndrome were reviewed with emphasis on all previously reported abnormalities and any possible additional ones. Most of the abnormalities occurred with the same frequency as previously reported, but some less freq...

T. Higuchi, W. J. Russell, M. Komatsuda, S. Neriishi

1968-01-01

348

Epilepsy and chromosomal abnormalities  

Microsoft Academic Search

BackgroundMany chromosomal abnormalities are associated with Central Nervous System (CNS) malformations and other neurological alterations,\\u000a among which seizures and epilepsy. Some of these show a peculiar epileptic and EEG pattern. We describe some epileptic syndromes\\u000a frequently reported in chromosomal disorders.\\u000a \\u000a \\u000a \\u000a \\u000a MethodsDetailed clinical assessment, electrophysiological studies, survey of the literature.\\u000a \\u000a \\u000a \\u000a ResultsIn some of these congenital syndromes the clinical presentation and EEG

Giovanni Sorge; Anna Sorge

2010-01-01

349

Readiness in the Basal Reader: An Update.  

ERIC Educational Resources Information Center

A study examined two 1989 basal reading series' (published by McGraw Hill and Holt) readiness/priming sequences in order to ascertain the theoretical bases of each and then compared the findings with those of an earlier study. All pages of the readiness/priming sequence student texts and workbooks of both basal reading series were analyzed using

Perkins, Pamela

350

Local synaptic connections of basal forebrain neurons  

Microsoft Academic Search

Single, biocytin filled neurons in combination with immunocytochemistry and retrograde tracing as well as material with traditional double-immunolabeling were used at the light and electron microscopic levels to study the neural circuitry within the basal forebrain. Cholinergic neurons projecting to the frontal cortex exhibited extensive local collaterals terminating on non-cholinergic, (possible GABAergic) neurons within the basal forebrain. Elaborate axon arbors

Laszlo Zaborszky; Alvaro Duque

2000-01-01

351

Modern basal insulin analogs: An incomplete story.  

PubMed

The currently available basal insulin does not completely mimic the endogenous insulin secretion. This has continued to promote the search for ideal basal insulin. The newer basal insulin have primarily focused on increasing the duration of action, reducing variability, and reducing the incidence of hypoglycemia, particularly nocturnal. However, the changing criteria of hypoglycemia within a short span of a few years along with the surprising introduction of major cardiac events as another outcome measure has not only clouded the assessment of basal insulin but has also polarized opinion worldwide about the utility of the newer basal insulin. A critical review of both the pre and post FDA analysis of all the basal insulin in this article attempts to clear some of the confusion surrounding the issues of hypoglycemia and glycemic control. This article also discusses all the trials and meta-analysis done on all the current basal insulin available along with their head-to-head comparison with particular attention to glycemic control and hypoglycemic events including severe and nocturnal hypoglycemia. This in-depth analysis hopes to provide a clear interpretation of the various analyses available in literature at this point of time thereby acting as an excellent guide to the readers in choosing the most appropriate basal insulin for their patient. PMID:25364672

Singh, Awadhesh Kumar; Gangopadhyay, Kalyan Kumar

2014-11-01

352

Spirometric abnormalities among welders  

SciTech Connect

A group of manual welders age group 13-60 years having a mean exposure period of 12.4 {plus minus} 1.12 years were subjected to spirometry to evaluate the prevalence of spirometric abnormalities. The welders showed a significantly higher prevalence of respiratory impairment than that observed among the unexposed controls as a result of exposure to welding gases which comprised fine particles of lead, zinc, chromium, and manganese. This occurred despite the lower concentration of the pollutants at the work place. In the expose group, the smoking welders showed a prevalence of respiratory impairment significantly higher than that observed in the nonsmoking welders. The results of the pulmonary function tests showed a predominantly restrictive type of pulmonary impairment followed by a mixed ventilatory defect among the welders. The effect of age on pulmonary impairment was not discernible. Welders exposed for over 10 years showed a prevalence of respiratory abnormalities significantly higher than those exposed for less than 10 years. Smoking also had a contributory role.

Rastogi, S.K.; Gupta, B.N.; Husain, T.; Mathur, N.; Srivastava, S. (Industrial Toxicology Research Centre, Lucknow (India))

1991-10-01

353

Analysis of T Cell Responses during Active Varicella-Zoster Virus Reactivation in Human Ganglia  

PubMed Central

ABSTRACT Varicella-zoster virus (VZV) is responsible for both varicella (chickenpox) and herpes zoster (shingles). During varicella, the virus establishes latency within the sensory ganglia and can reactivate to cause herpes zoster, but the immune responses that occur in ganglia during herpes zoster have not previously been defined. We examined ganglia obtained from individuals who, at the time of death, had active herpes zoster. Ganglia innervating the site of the cutaneous herpes zoster rash showed evidence of necrosis, secondary to vasculitis, or localized hemorrhage. Despite this, there was limited evidence of VZV antigen expression, although a large inflammatory infiltrate was observed. Characterization of the infiltrating T cells showed a large number of infiltrating CD4+ T cells and cytolytic CD8+ T cells. Many of the infiltrating T cells were closely associated with neurons within the reactivated ganglia, yet there was little evidence of T cell-induced neuronal apoptosis. Notably, an upregulation in the expression of major histocompatibility complex class I (MHC-I) and MHC-II molecules was observed on satellite glial cells, implying these cells play an active role in directing the immune response during herpes zoster. This is the first detailed characterization of the interaction between T cells and neuronal cells within ganglia obtained from patients suffering herpes zoster at the time of death and provides evidence that CD4+ and cytolytic CD8+ T cell responses play an important role in controlling VZV replication in ganglia during active herpes zoster. IMPORTANCE VZV is responsible for both varicella (chickenpox) and herpes zoster (shingles). During varicella, the virus establishes a life-long dormant infection within the sensory ganglia and can reawaken to cause herpes zoster, but the immune responses that occur in ganglia during herpes zoster have not previously been defined. We examined ganglia obtained from individuals who, at the time of death, had active herpes zoster. We found that specific T cell subsets are likely to play an important role in controlling VZV replication in ganglia during active herpes zoster. PMID:24352459

Steain, Megan; Sutherland, Jeremy P.; Rodriguez, Michael; Cunningham, Anthony L.; Slobedman, Barry

2014-01-01

354

ACETYLCHOLINESTERASE IN FROG SYMPATHETIC AND DORSAL ROOT GANGLIA  

PubMed Central

The localization and chemical determination of acetylcholin esterase in the frog sympathetic and dorsal root ganglia were studied by a combination of the methods of electron microscopy, histochemistry, and microgasometric analysis with the magnetic diver. The Koelle-Friedenwald copper thiocholine histochemical method was modified by eliminating the sulfide conversion and by treatment of the tissue with potassium permanganate. In fixed tissue, enzymatic activity was demonstrated on the inner surface of the endoplasmic reticulum, nuclear envelope, subsurface cisternae, and agranular reticulum of the perikaryon and axon. In briefly fixed tissue, end product appeared also at the axon-sheath and the sheath-sheath interface. Activity at the synaptic junction was most readily obtained in unfixed tissue. Isolated neurons recovered from the diver following chemical analysis were studied with the electron microscope. Cells having a high enzyme activity showed a badly ruptured or absent neural plasmalemma and sheath. In this case the measured activity was apparently due to the enzyme present in the endoplasmic reticulum. Neurons having low activity exhibited an intact plasmalemma and sheath. This may reflect the effectiveness of the neural plasmalemma and sheath as a penetration barrier. The effects of fixation on enzyme activity are discussed. Electron microscopic examination of cells following microgasometric analysis is shown to be essential for the interpretation of the biochemical data. PMID:19866698

Brzin, Miro; Tennyson, Virginia M.; Duffy, Philip E.

1966-01-01

355

MRI-identified abnormalities and wrist range of motion in asymptomatic versus symptomatic computer users  

PubMed Central

Background Previous work has shown an association between restricted wrist range of motion (ROM) and upper extremity musculoskeletal disorders in computer users. We compared the prevalence of MRI-identified wrist abnormalities and wrist ROM between asymptomatic and symptomatic computer users. Methods MR images at 1.5 T of both wrists were obtained from 10 asymptomatic controls (8 F, 2 M) and 14 computer users (10 F, 4 M) with chronic wrist pain (10 bilateral; 4 right-side). Maximum wrist range of motion in flexion and radioulnar deviation was measured with an electrogoniometer. Results Extraosseous ganglia were identified in 66.6% of asymptomatic wrists and in 75% of symptomatic wrists. Intraosseous ganglia were identified in 45.8% of asymptomatic wrists and in 75% of symptomatic wrists, and were significantly (p < .05) larger in the symptomatic wrists. Distal ECU tendon instability was identified in 58.4% of both asymptomatic and symptomatic wrists. Dominant wrist flexion was significantly greater in the asymptomatic group (68.8 6.7 deg.) compared to the symptomatic group (60.7 7.3 deg.), p < .01. There was no significant correlation between wrist flexion and intraosseous ganglion burden (p = .09) Conclusions This appears to be the first MRI study of wrist abnormalities in computer users. This study demonstrates that a variety of wrist abnormalities are common in computer users and that only intraosseous ganglia prevalence and size differed between asymptomatic and symptomatic wrists. Flexion was restricted in the dominant wrist of the symptomatic group, but the correlation between wrist flexion and intraosseous ganglion burden did not reach significance. Flexion restriction may be an indicator of increased joint loading, and identifying the cause may help to guide preventive and therapeutic interventions. PMID:21108817

2010-01-01

356

Involvement of the suboesophageal and thoracic ganglia in the control of antennal movements in crickets  

Microsoft Academic Search

In crickets (Gryllus campestris, Gryllus bimaculatus) the contribution of the suboesophageal ganglia (SOG) and thoracic ganglia to the generation of antennal movements during\\u000a visual tracking, walking and flight was investigated by the transection of connectives. Transection of one circumoesophageal\\u000a connective abolished the movements and postures of the antenna ipsilateral to the lesion, while the contralateral antenna\\u000a behaved normally. Simple antennal

B. G. Horseman; M. J. Gebhardt; H. W. Honegger

1997-01-01

357

Quantitation of Latent Varicella-Zoster Virus and Herpes Simplex Virus Genomes in Human Trigeminal Ganglia  

Microsoft Academic Search

Using real-time fluorescence PCR, we quantitated the numbers of copies of latent varicella-zoster virus (VZV) and herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) genomes in 15 human trigeminal ganglia. Eight (53%) and 1 (7%) of 15 ganglia were PCR positive for HSV-1 or -2 glycoprotein G genes, with means of 2,902 6 1,082 (standard error of the

STEPHANIE R. PEVENSTEIN; RICHARD K. WILLIAMS; DANIEL MCCHESNEY; ERIK K. MONT; JOHN E. SMIALEK; STEPHEN E. STRAUS

1999-01-01

358

Neglected Giant Scalp Basal Cell Carcinoma  

PubMed Central

Summary: Rarely, basal cell carcinoma grows to a giant size, invading the underlying deep tissue and complicating the treatment and reconstruction modalities. A giant basal cell carcinoma on the scalp is in some cases treated with a combination of surgery and radiation therapy, resulting in local control, a satisfactory long-term cosmetic and functional result. We present a case with a neglected basal cell scalp carcinoma, treated with wide excision and postoperative radiotherapy, reconstructed with a free latissimus dorsi flap. The cosmetic result is acceptable and there is no sign of recurrence 1 year postoperatively.

El-Charnoubi, Waseem-Asim Ghulam; Gehl, Julie; Krag, Christen

2014-01-01

359

MHC class II antigen-expressing cells in cardiac ganglia of the rat.  

PubMed

Cardiac ganglia develop destructive ganglionitis in chronic Chagas' disease and rheumatic heart disease. This ganglionitis is associated with periganglionic infiltrations and is suspected of developing secondary to epicardial inflammation. If so, it would be expected that cardiac ganglia (1) are equipped with an inventory of immune competent cells allowing the initiation of inflammatory processes, and (2) are not effectively protected from the milieu of the surrounding tissue by metabolically active diffusion barriers. These problems were addressed in specified pathogen-free rats by electron microscopy and immunohistochemistry with markers for dendritic cells, monocytes/macrophages, and perineurial barriers. In contrast to nerve fascicles, cardiac ganglia are only partially enveloped by perineurial cells. Inside the ganglia, ramified cells with major histocompatibility complex class II antigen (reacting with monoclonal antibody OX6) on their surface and exhibiting an ultrastructure typical of dendritic cells are numerous, comprising nearly 5% of all cells within ganglia. The ratio of the number of these cells to that of neurons is 1:2. Cells reacting with monoclonal antibodies ED1 and ED2, markers for monocytes/macrophages, constitute 1.8% and 1.6% of the ganglionic cell population, respectively. Such cells are less frequent in the cervical trunk of the vagus nerve. Thus, the inventory of immune competent cells in rat cardiac ganglia is consistent with the view that the abundance of antigen-presenting cells correlates with the permeability of the barriers providing protection from blood-borne and tissue-borne factors. PMID:15517402

Kummer, Wolfgang; Stommel, Carolin; Grau, Veronika

2005-01-01

360

Local synaptic connections of basal forebrain neurons.  

PubMed

Single, biocytin filled neurons in combination with immunocytochemistry and retrograde tracing as well as material with traditional double-immunolabeling were used at the light and electron microscopic levels to study the neural circuitry within the basal forebrain. Cholinergic neurons projecting to the frontal cortex exhibited extensive local collaterals terminating on non-cholinergic, (possible GABAergic) neurons within the basal forebrain. Elaborate axon arbors confined to the basal forebrain region also originated from NPY, somatostatin and other non-cholinergic interneurons. It is proposed that putative interneurons together with local collaterals from projection neurons contribute to regional integrative processing in the basal forebrain that may participate in more selective functions, such as attention and cortical plasticity. PMID:11000417

Zaborszky, L; Duque, A

2000-11-01

361

Astrocytes Are Endogenous Regulators of Basal Transmission  

E-print Network

by adenosine. Our work uncovers an essential role for astrocytes in the regulation of elementary synaptic synapses. In fact, the release of neurotransmitters induced by single action potentials, known as basal

Contractor, Anis

362

Basal constriction : shaping the vertebrate brain  

E-print Network

Organs are primarily formed from epithelia, polarized sheets of cells with an apical surface facing a lumen and basal surface resting on the underlying extracellular matrix. Cells within a sheet are joined by junctions, ...

Graeden, Ellie Graham

2011-01-01

363

Jaw mechanics in basal ceratopsia (Ornithischia, Dinosauria).  

PubMed

Ceratopsian dinosaurs were a dominant group of herbivores in Cretaceous terrestrial ecosystems. We hypothesize that an understanding of the feeding system will provide important insight into the evolutionary success of these animals. The mandibular mechanics of eight genera of basal ceratopsians was examined to understand the variability in shape of the jaws and the early evolution of the masticatory system in Ceratopsia. Data were collected on lever arms, cranial angles and tooth row lengths. The results indicate that psittacosaurids had higher leverage at the beak and in the rostral part of the tooth row than basal neoceratopsians, but lower leverage in the caudal part of the tooth row. Although the vertebrate mandible is generally considered as a third-class lever, that of basal neoceratopsians acted as a second-class lever at the caudal part of the tooth row, as is also true in ceratopsids. When total input force from the mandibular adductor muscles on both sides of the skull is considered, the largest bite force in basal ceratopsian tooth rows was exerted in the caudal part of the tooth row at the caudal extremity of the zone with near-maximum input force. Medially positioned teeth generate higher leverage than laterally positioned teeth. The largest bite force in all basal ceratopsians is smaller than the maximum input force, a limit imposed by the morphology of the basal ceratopsian masticatory system. In ceratopsids, caudal extension of the tooth row resulted in a much larger bite force, even exceeding the maximum input force. PMID:19711460

Tanoue, Kyo; Grandstaff, Barbara S; You, Hai-Lu; Dodson, Peter

2009-09-01

364

Arm Trajectories in Dyskinetic Cerebral Palsy Have Increased Random Variability  

Microsoft Academic Search

Dyskinetic cerebral palsy results from injury to the basal ganglia early in life. Symptoms can include hyperkinetic or dystonic arm movements that impair function. It is not known whether these movements comprise a small number of specific abnormal motor patterns or whether they are random and variable. We hypothesize that injury to the basal ganglia leads to impaired filtering and

Terence D. Sanger

2006-01-01

365

Systemic abnormalities in liver disease  

PubMed Central

Systemic abnormalities often occur in patients with liver disease. In particular, cardiopulmonary or renal diseases accompanied by advanced liver disease can be serious and may determine the quality of life and prognosis of patients. Therefore, both hepatologists and non-hepatologists should pay attention to such abnormalities in the management of patients with liver diseases. PMID:19554648

Minemura, Masami; Tajiri, Kazuto; Shimizu, Yukihiro

2009-01-01

366

TMI abnormal waste project plan  

Microsoft Academic Search

This report discusses plans for the TMI Abnormal Waste Project, which is part of the EPICOR and Waste Research and Disposition Program and funded by the US Department of Energy. The sequence proposed for disposition of Three Mile Island (TMI) abnormal wastes includes: (a) packaging at TMI, (b) shipment to the Idaho National Engineering Laboratory (INEL), (c) storage at INEL

Ayers; A. L. Jr

1984-01-01

367

Students' reactions to abnormal psychology  

Microsoft Academic Search

As a result of some concern about the effect of courses in abnormal psychology on students, a questionnaire was presented to several classes at the close of the course. The majority answering the questionnaire felt the course to be beneficial, giving evidence that the study of abnormal psychology need not be generally harmful, and may have a significant place in

W. S. Taylor

1932-01-01

368

abnormalities in infants and toddlers  

E-print Network

, Akshoomoff 2000). Similarly, patients with fetal alcohol syndrome (FAS) have decreased cerebellar volumesCerebellar abnormalities in infants and toddlers with Williams syndrome Wendy Jones* PhD, The Salk-mail: jones@crl.ucsd.edu One commonly observed neuroanatomical abnormality in adults with Williams syndrome

Bellugi, Ursula

369

Resolution of cranial MRI and SPECT abnormalities in a patient with Wilson's disease following oral zinc monotherapy.  

PubMed

A 38-year-old woman with Wilson's disease developed neurological deterioration after 25 years of low-dose penicillamine administration. She showed an akinetic-rigid syndrome and cerebellar motor ataxia. Brain MRI showed increased signal intensity at the bilateral pons, midbrain, putamen, and thalamus. 123I-IMP-SPECT revealed a diffuse reduction of cerebral blood flow at the bilateral cerebral hemisphere including the basal ganglia. After the patient's regimen was changed to zinc therapy, her neurological condition gradually improved, and she showed almost complete recovery within two years. Serial MRI and SPECT studies showed a marked improvement in the lesions. PMID:22790141

Ishida, Shimon; Doi, Yoshimitsu; Yamane, Kazushi; Sugino, Masakazu; Kimura, Fumiharu; Hanafusa, Toshiaki; Fukui, Hideo; Tamai, Hiroshi

2012-01-01

370

Position of Larval Tapeworms, Polypocephalus sp., in the Ganglia of Shrimp, Litopenaeus setiferus  

PubMed Central

Parasites that invade the nervous system of their hosts have perhaps the best potential to manipulate their hosts behavior, but how they manipulate the host, if they do at all, could depend on their position within the hosts nervous system. We hypothesize that parasites that live in the nervous system of their host will be randomly distributed if they exert their influence through non-specific effects (i.e., general pathology), but that their position in the nervous system will be non-random if they exert their influence by targeting specific neural circuits. We recorded the position of larval tapeworms, Polypocephalus sp., in the abdominal ganglia of white shrimp, Litopenaeus setiferus. Tapeworms are more common within ganglia than in the section of the nerve cord between ganglia, even though the nerve cord has a greater volume than the ganglia. The tapeworms are also more abundant in the periphery of the ganglia. Because most synaptic connections are within the central region of the ganglion, such positioning may represent a trade-off between controlling the nervous system and damaging it. PMID:24820854

Carreon, Nadia; Faulkes, Zen

2014-01-01

371

Type I IFN suppresses Cxcr2 driven neutrophil recruitment into the sensory ganglia during viral infection.  

PubMed

Infection induces the expression of inflammatory chemokines that recruit immune cells to the site of inflammation. Whereas tissues such as the intestine and skin express unique chemokines during homeostasis, whether different tissues express distinct chemokine profiles during inflammation remains unclear. With this in mind, we performed a comprehensive screen of the chemokines expressed by two tissues (skin and sensory ganglia) infected with a common viral pathogen (herpes simplex virus type 1). After infection, the skin and ganglia showed marked differences in their expression of the family of Cxcr2 chemokine ligands. Specifically, Cxcl1/2/3, which in turn controlled neutrophil recruitment, was up-regulated in the skin but absent from the ganglia. Within the ganglia, Cxcl2 expression and subsequent neutrophil recruitment was inhibited by type I interferon (IFN). Using a combination of bone marrow chimeras and intracellular chemokine staining, we show that type I IFN acted by directly suppressing Cxcl2 expression by monocytes, abrogating their ability to recruit neutrophils to the ganglia. Overall, our findings describe a novel role for IFN in the direct, and selective, inhibition of Cxcr2 chemokine ligands, which results in the inhibition of neutrophil recruitment to neuronal tissue. PMID:24752295

Stock, Angus T; Smith, Jeffrey M; Carbone, Francis R

2014-05-01

372

Constraining basal hydrology with model inversions of basal friction using new InSAR surface velocities.  

NASA Astrophysics Data System (ADS)

Constraining ice flow models for continental ice sheets such as Antarctica or Greenland can be difficult, especially regarding the specification of basal friction at the ice/bed interface. Historically, two approches have been taken: 1) model the basal hydrology of the ice sheet, and relate the resulting basal water pressure to the basal drag coefficient and 2) invert for the basal drag coefficient using InSAR surface velocities, and infer the resulting basal hydrology. Here, we use both approaches within the Ice Sheet System Model (ISSM), the JPL/UCI developed ice flow model, for which we develop a new hydrological model based on Johnson et al 2002. We compare this model against a massive inversion of Antarctica's basal drag coefficient using new InSAR surface velocities from Rignot et al 2011. We discuss the potential for this model to improve constraints on basal friction evolution, and implications for projections of ice flow dynamics in a changing climate. This work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration's Cryosphere Science Program.

Larour, E. Y.; Rignot, E. J.; Seroussi, H. L.; Morlighem, M.

2011-12-01

373

Cutaneous basal cell carcinoma of vulva.  

PubMed

Eleven cases of basal cell carcinoma of the vulvar skin are reported. There was fairly close correlation between the histologic type and the gross appearance of the lesion. The average age of the patients was 59 years, and the presenting complaint was usually that of a nodule with associated irritation or pruritus. All patients were treated surgically and none have had recurrent or metastatic disease; six patients have been followed for 12 to 25 years. The treatment of choice is wide local excision. One tumor was of particular interest in that it represented a carcinomatous change in a pre-existing premalignant fibroepithelial tumor. Basal cell carcinoma of the skin must be distinguished from adenoid cystic (basal cell) carcinoma of vestibular glands, which is a more aggressive neoplasm and which metastasizes by the lymphatic and blood vascular systems. PMID:1192371

Cruz-Jimenez, P R; Abell, M R

1975-11-01

374

Sonography-Assisted Arthroscopic Resection of Volar Wrist Ganglia: A New Technique  

PubMed Central

Although satisfactory arthroscopic resection of volar wrist ganglia has been reported recently, the risk of damage to arteries, nerves, and tendons remains. Furthermore, ganglia and their stalks cannot be visualized arthroscopically in many cases, and surgeons must perform a blind resection of the joint capsule until ganglion cysts or their stalks appear. Sonography has limited resolution, but recent improvements in hardware and software have made it an excellent noninvasive and dynamic imaging technique for assessing the musculoskeletal system. Ganglia, tendons, nerves, and vessels around the lesion can be clearly observed by sonography. Furthermore, the cyclic motion of the arthroscopic shaver tip makes identification by sonography easy and assists in guiding the surgeon to the lesion. PMID:23766971

Yamamoto, Michiro; Kurimoto, Shigeru; Okui, Nobuyuki; Tatebe, Masahiro; Shinohara, Takaaki; Hirata, Hitoshi

2012-01-01

375

Basal reading programs: Development, effectiveness, and selection  

Microsoft Academic Search

F rom observing a lot of classrooms, talking with many teachers and school administrators, and reviewing a great deal of the classroom observation literature, we have come to believe that commercially developed basal reading programs account for a great deal of how time is spent during the periods allocated for reading instruction in elementary classrooms. This belief is further substantiated

Jean Osborn; Marcy Stein

1985-01-01

376

TEMPORAL VARIABILITY IN BASAL ISOPRENE EMISSION FACTOR  

EPA Science Inventory

Seasonal variability in basal isoprene emission factor (micrograms C /g hr or nmol/ m2 sec, leaf temperature at 30 degrees C and photosynthetically active radiation (PAR) at 1000 micromol/ m2 sec) was studied during the 1998 growing season at Duke Forest in the North Carolina Pie...

377

PORTRAYAL OF THE ELDERLY IN BASAL READERS  

Microsoft Academic Search

Six children's basal reading series, published between 1976 and 1978, were examined for the frequency and quality of the portrayal of elderly characters, especially those in a central role. The racial\\/ethnic and sex representation of the elderly was examined. The extent of their participation, their personal characteristics, how they were physically described in the text, and how they were illustrated,

Jerilyn K. Ribovich; Ardeth M. Deay

1979-01-01

378

Portrayal of the Elderly in Basal Readers.  

ERIC Educational Resources Information Center

Reports that 16 percent of 1,600 selections from six basal reading series contained one or more old people, that six percent presented an elderly person in a central role, that women and minority groups were inadequately represented, that the portrayal of old people was basically positive, and that considerable stereotyping existed in

Deay, Ardeth M.; Ribovich, Jerilyn K.

1979-01-01

379

Anatomy of giant serotonin-containing neurones in the cerebral ganglia of Helix pomatia and Limax maximus  

Microsoft Academic Search

There is a giant serotonin-containing neurone (GSC) in each cerebral ganglion of Helix pomatia and Limax maximus. In Helix, presynaptic endings of the GSCs are located in the buccal ganglia and peripheral musculature. Dense-cored vesicles of mean diameter 100 nm were observed in the perikarya and the axon branches of the GSCs within the cerebral ganglia. Evidence is presented which

V. W. Pentreath; N. N. Osborne; G. A. Cottrell

1973-01-01

380

Attenuation of abnormal glutamate release in zinc deficiency by zinc and Yokukansan.  

PubMed

The mechanism of the abnormal increase in extracellular glutamate concentration in the hippocampus induced with 100mM KCl in zinc deficiency is unknown. In the present study, the changes in glutamate release (exocytosis) and GLT-1, a glial glutamate transporter, expression were studied in young rats fed a zinc-deficient diet for 4 weeks. Exocytosis at mossy fiber boutons was enhanced as reported previously and GLT-1 protein was increased in the hippocampus. The enhanced exocytosis is thought to increase extracellular glutamate concentration. However, the basal concentration of extracellular glutamate in the hippocampus was not increased by zinc deficiency, suggesting that GLT-1 protein increased serves to maintain the basal concentration of extracellular glutamate. The enhanced exocytosis was attenuated in the presence of 100microM ZnCl(2), which attenuated the abnormal increase in extracellular glutamate induced with high K(+) in zinc deficiency. The present study indicates that zinc attenuates abnormal glutamate release in zinc deficiency. The enhanced exocytosis was also attenuated in slices from zinc-deficient rats administered Yokukansan, a herbal medicine, in which the abnormal increase in extracellular glutamate induced with high K(+) was attenuated. It is likely that Yokukansan is useful for prevention or cure of abnormal glutamate release. The enhanced exocytosis in zinc deficiency is a possible mechanism on abnormal increase in extracellular glutamate in the hippocampus induced with high K(+). PMID:18755231

Takeda, Atsushi; Tamano, Haruna; Itoh, Hiromasa; Oku, Naoto

2008-12-01

381

Temporal variability in basal isoprene emission factor.  

PubMed

Seasonal variability in basal isoprene emission factor (&mgr;g C g(-1) h(-1) or nmol m(-2) s(-1), leaf temperature at 30 degrees C and photosynthetically active radiation (PAR) at 1000 &mgr;mol m(-2) s(-1)) was studied during the 1998 growing season at Duke Forest in the North Carolina Piedmont. Emissions from eight upper-canopy white oak (Quercus alba L.) leaves were measured periodically from the onset of isoprene emission on Day of Year (DOY) 119 (April 29) to leaf senescence in late October (DOY 299). Emissions from four leaves were measured under basal conditions with a controlled-environment cuvette system equipped with 10-ml gas-tight syringes and a reduction gas detector. Emissions from the other four leaves were measured under ambient conditions with the same system. Emission rates from the four leaves measured under ambient conditions were adjusted to basal conditions based on the PAR and leaf temperature algorithms of Guenther et al. (1993). The seasonal onset of isoprene emission was in agreement with previous studies where cumulative degree days from the date of the last spring frost were used to estimate bud break, leaf expansion, and increase in basal emission factor (EF). Between DOY 141 (May 21) and 240 (August 28), mean meteorological conditions 6 to 18 h prior to the EF measurements (ambient PAR and temperature) explained up to 78% of the variability in mean basal EF between measurement periods. Summertime mean isoprene emission potential was reached on DOY 141 (May 21) and was maintained until DOY 240 (August 28), when isoprene emission began to decline monotonically as leaf senescence approached. The mean value for leaves measured under ambient conditions and adjusted to basal conditions for DOY 141-240 was 75.6 &mgr;g C g(-1) h(-1) (74.2-79.1), whereas the mean value for leaves measured under basal conditions was 72.9 &mgr;g C g(-1) h(-1) (64.7-88.9). Between DOY 141 and 240, daily mean isoprene EFs varied from 54 to 96 &mgr;g C g(-1) h(-1) (27 to 49 nmol m(-2) s(-1)). In agreement with previous work at this and other sites, basal isoprene emission rates of fully exposed leaves at the crown apex of this tree were about 20% higher than those of the selected leaves. The length of the period prior to measurement of isoprene emission, during which meteorology was correlated with basal EF, appeared to be related to the timing and periodicity of meteorological change, and probably explains quantitative differences in the length of this period among studies. The empirical equation that we derived for this effect explained variability in midday EFs at the study site, but its general applicability remains to be tested. Strong diurnal changes in EF (as high as a factor of 2) are implied in this study, and should be examined further. PMID:12651500

Geron, Chris; Guenther, Alex; Sharkey, Tom; Arnts, Robert R.

2000-06-01

382

Basal autophagy induction without AMP-activated protein kinase under low glucose conditions  

PubMed Central

When ATP levels in a cell decrease, various homeostatic intracellular mechanisms initiate attempts to restore ATP levels. As a prominent energy sensor, AMP-activated protein kinase (AMPK) represents one molecular gauge that links energy levels to regulation of anabolic and catabolic processes to restore energy balance. Although pharmacological studies have suggested that an AMPK activator, AICAR (5-aminoimidazole-4-carboxamide ribonucleoside) may link AMPK activation to autophagy, a process that can provide short-term energy within the cell, AICAR can have AMPK-independent effects. Therefore, using a genetic-based approach we investigated the role of AMPK in cellular energy balance. We demonstrate that genetically altered cells, mouse embryonic fibroblasts (MEFs), lacking functional AMPK, display altered energy balance under basal conditions and die prematurely under low glucose-serum starvation challenge. These AMPK mutant cells appear to be abnormally reliant on autophagy under low glucose basal conditions, and therefore cannot rely further on autophagy like wild-type cells during further energetic stress and instead undergo apoptosis. This data suggests that AMPK helps regulate basal energy levels under low glucose. Further, AMPK mutant cells show increased basal phosphorylation of p53 at serine 15, a residue phosphorylated under glucose deprivation. We propose that cells lacking AMPK function have altered p53 activity that may help sensitize these cells to apoptosis under energetic stress. PMID:19844161

Williams, Tyisha; Forsberg, Lawrence J.; Viollet, Benoit; Brenman, Jay E.

2014-01-01

383

The mammalian sympathetic prevertebral ganglia: models for the study of neuronal networks and basic neuronal properties.  

PubMed

The mammalian sympathetic prevertebral ganglia regulate various visceral functions and in particular the digestive tract motility. Several integrative properties of these ganglia have been described: convergence of central inputs, projection of visceral inputs at the pre- and post synaptic level and pacemaker activity of the neurones. This review presents the results obtained on another integrative property which has been widely studied over the last 10 years: the modulation of the fast central inputs by neuromodulators such as nitric oxide, ceramide and GABA. These substances facilitate or inhibit the fast central inputs through complex interrelated actions. We also present striking results recently obtained during the study of a regulatory reflex of the digestive tract motility organized by the prevertebral ganglia: the gastro-duodenal inhibitory reflex. During this reflex, the neurotransmitter released by the visceral afferent fibres to activate the ganglionic neurones is gaseous: nitric oxide. Moreover, the mechanism conducting the excitation along the afferent and efferent fibres is independent of action potentials. This mechanism requires the integrity of the membrane lipid rafts and the activation in cascade of the following second messenger sequence: ceramide, calcium, nitric oxide and guanosine 3', 5'-cyclic monophosphate. The existence of this mechanism gives grounds for rethinking one of the central dogmas in neuroscience according to which excitation is only conducted along nerves by an electrical phenomenon, the action potential. All these results strengthen the role of the prevertebral ganglia as a model for the study of neuronal networks and basic neuronal properties. PMID:19581130

Fasano, Caroline; Niel, Jean-Pierre

2009-10-01

384

CONTRAST BETWEEN OSMIUM-FIXED AND PERMANGANATE-FIX ED TOAD SPINAL GANGLIA  

Microsoft Academic Search

Chains of vesicles are prominent near the plasma membranes of both the neurons and satellite cells of osmium-fixed toad spinal ganglia. In permanganate-fixed specimens, how- ever, such vesicles are absent, and in their place are continuous invaginations of the plasma membranes of these ceils. The discrepancy suggests that the serried vesicles seen in osmium- fixed preparations arise through disintegration of

JACK ROSENBLUTH

2009-01-01

385

Direct NK Cell-Mediated Lysis of Syngenic Dorsal Root Ganglia Neurons In Vitro1  

Microsoft Academic Search

In contrast to extensive studies on the role of T and B lymphocytes in the pathogenesis of autoimmune diseases of the nervous system, little is known about NK cells and their potential role in the destruction of neural tissue. NK cells have been implicated in the selective death of sympathetic neurons resident in the superior cervical ganglia of rats after

Eva Backstrom; Benedict J. Chambers; Krister Kristensson; Hans-Gustaf Ljunggren

2000-01-01

386

Lumbar spinal ganglia enhancement after Gadolinium chelate administration: a radio-histological correlation  

Microsoft Academic Search

: The aim of the present study was to assess the frequency of enhancement of lumbar spinal ganglia after Gadolinium chelate injection in patients without radiculopathy, and to correlate the enhancement with histology. This study is based on the analysis of MR lumbar examinations conducted on 18 patients without radicular symptoms, or previous surgery of the lumbar spine, or disease

X. Demondion; X. Leroy; F. Lapgue; A. Drizenko; J.-P. Francke; A. Cotten

2002-01-01

387

Upregulation of Ryk expression in rat dorsal root ganglia after peripheral nerve injury  

Microsoft Academic Search

To study changes of Ryk expression in dorsal root ganglia (DRG) after peripheral nerve injury, we set up an animal model of unilateral sciatic nerve lesioned rats. Changes of Ryk protein expression in DRG neurons after unilateral sciatic nerve injury were investigated by immunostaining. Changes of Ryk mRNA were also tested by semi-quantitative PCR concurrently. We found, both at the

Xin Li; Yao-hua Li; Shun Yu; Yaobo Liu

2008-01-01

388

Neural basis of singing in crickets: central pattern generation in abdominal ganglia  

NASA Astrophysics Data System (ADS)

The neural mechanisms underlying cricket singing behavior have been the focus of several studies, but the central pattern generator (CPG) for singing has not been localized conclusively. To test if the abdominal ganglia contribute to the singing motor pattern and to analyze if parts of the singing CPG are located in these ganglia, we systematically truncated the abdominal nerve cord of fictively singing crickets while recording the singing motor pattern from a front-wing nerve. Severing the connectives anywhere between terminal ganglion and abdominal ganglion A3 did not preclude singing, although the motor pattern became more variable and failure-prone as more ganglia were disconnected. Singing terminated immediately and permanently after transecting the connectives between the metathoracic ganglion complex and the first unfused abdominal ganglion A3. The contribution of abdominal ganglia for singing pattern generation was confirmed by intracellular interneuron recordings and current injections. During fictive singing, an ascending interneuron with its soma and dendrite in A3 depolarized rhythmically. It spiked 10 ms before the wing-opener activity and hyperpolarized in phase with the wing-closer activity. Depolarizing current injection elicited rhythmic membrane potential oscillations and spike bursts that elicited additional syllables and reliably reset the ongoing chirp rhythm. Our results disclose that the abdominal ganglion A3 is directly involved in generating the singing motor pattern, whereas the more posterior ganglia seem to provide only stabilizing feedback to the CPG circuit. Localizing the singing CPG in the anterior abdominal neuromeres now allows analyzing its circuitry at the level of identified interneurons in subsequent studies.

Schneich, Stefan; Hedwig, Berthold

2011-12-01

389

Immune abnormalities in myelodysplastic syndromes.  

PubMed Central

The immune states of 52 patients with myelodysplastic syndromes classified according to the FAB criteria were studied. Serum electrophoresis and immunoelectrophoresis, direct Coombs test, and tests for organ and non-organ specific antibodies were performed. Twenty six patients had immunoglobulin abnormalities: six (11.5%) had monoclonal gammopathy; 17 (32.6%) had polyclonal increases in serum immunoglobulin; while in three (5.8%) immunoglobulin concentrations were decreased. The distribution of immunoglobulin abnormalities among the five myelodysplastic syndrome subtypes was fairly uniform. Results of direct Coombs test were negative in all cases. Organ specific antibodies were not detected in any of the patients tested, although two patients were found positive for antinuclear antibodies. The presence of immunoglobulin abnormalities indicates an involvement of the lymphoplasmatic system in myelodysplastic syndromes. PMID:3928701

Economopoulos, T; Economidou, J; Giannopoulos, G; Terzoglou, C; Papageorgiou, E; Dervenoulas, J; Arseni, P; Hadjioannou, J; Raptis, S

1985-01-01

390

Abnormal waves during Hurricane Camille  

NASA Astrophysics Data System (ADS)

A reanalysis is reported of the wave time series recorded during Hurricane Camille having as objective the identification of individual waves that satisfy current criteria defining abnormal or freak waves. It is shown that during the hurricane development, a very nonstationary situation has occurred during which the second-order sea state parameters changed significantly with time. The parameters of the largest individual waves in sea states which identify abnormal waves did not show any clear trend, and such waves occurred during the development stage and not when the significant wave height was the largest. It is argued that the present criteria of identification of abnormal waves are not satisfactory, as they do not take into account the nature of the sea states in which the waves occur.

Guedes Soares, C.; Cherneva, Z.; AntO, E. M.

2004-08-01

391

Complex patterns of abnormal heartbeats  

NASA Astrophysics Data System (ADS)

Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical ``heartprints'' which reveal characteristic patterns in long clinical records encompassing ~105 heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch.; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

2002-09-01

392

Complex patterns of abnormal heartbeats  

NASA Technical Reports Server (NTRS)

Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

2002-01-01

393

Basal hydraulic conditions of Ice Stream B  

NASA Technical Reports Server (NTRS)

Fifteen boreholes have been drilled to the base of Ice Stream B in the vicinity of UpB Camp. The boreholes are spread over an area of about 500 x 1000 m. Several till cores were retrieved from the bottom of the 1000-m-deep holes. Laboratory tests using a simple shear box revealed a yield strength of basal till of 2 kPa. This agrees well with in-situ measurements using a shear vane. Since the average basal shear stress of Ice Stream B with a surface slope of 0.1 degree is about 20 kPa, the ice stream cannot be supported by till that weak. Additional support for this conclusion comes from the basal water pressure that has been measured in all boreholes as soon as the hot water drill reached bottom. In several boreholes, the water pressure has been continuously monitored; in two of them, over several years. The water pressure varies but stays within 1 bar of flotation where ice overburden pressure and water pressure are equal. The ratio of water and overburden pressure lies between 0.986 and 1.002. This is an extremely high value as compared to other fast-moving ice masses; e.g., Variegated Glacier in surge has a ratio of 0.8, and Columbia Glacier - a fast-moving tidewater glacier - has a ratio of 0.9. It implies that water flow under the glacier occurs in a thin film and not in conduits that would drain away water too rapidly. It also implies that basal sliding must be very effective. Water flow under the glacier was measured in a salt-injection experiment where a salt pulse was released at the bottom of a borehole while 60 m down-glacier, the electrical resistance was measured between two other boreholes. A flow velocity of 7 mm/s was obtained.

Engelhardt, Hermann; Kamb, Barclay

1993-01-01

394

Horrifying Basal cell carcinoma: cytological, immunohistochemical, and ultrastructural findings.  

PubMed

Basal cell carcinoma (BCC) is a slow-growing and frequently occurring tumor of the eyelids. Among BCC cases, there is a subtype of aggressive cases called horrifying BCC (HBCC). There are also rare BCC cases that show neuroendocrine differentiation. Here, we describe a case of HBCC with neuroendocrine differentiation. The patient, a 41-year-old woman, presented with abnormal left eye tearing and left cheek pain. On computed tomography imaging, a tumor that extended to the left orbit was detected in the left cheek. On cytological examination of fine-needle aspiration (FNA) samples, the tumor cells were observed as sheet-like clusters and single bare nuclei with a clear background; peripheral palisading was not clearly seen. On examination of the biopsy specimen taken after FNA, the tumor was found to be composed of cancer cell nests with scattered peripheral palisading in the dermis. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) 7 and CD56 and were negative for CK20, synaptophysin, and chromogranin A. Membrane-bound dense-core granules were detected on ultrastructural study. A HBCC case with neuroendocrine differentiation has not been previously reported. The correlation between the presence of neuroendocrine differentiation in HBCC and patient prognosis should be further studied. PMID:25120472

Kinoshita, Yuichi; Takasu, Kosho; Yoshizawa, Katsuhiko; Emoto, Yuko; Yuki, Michiko; Yuri, Takashi; Shikata, Nobuaki; Tsubura, Airo

2014-05-01

395

Horrifying Basal Cell Carcinoma: Cytological, Immunohistochemical, and Ultrastructural Findings  

PubMed Central

Basal cell carcinoma (BCC) is a slow-growing and frequently occurring tumor of the eyelids. Among BCC cases, there is a subtype of aggressive cases called horrifying BCC (HBCC). There are also rare BCC cases that show neuroendocrine differentiation. Here, we describe a case of HBCC with neuroendocrine differentiation. The patient, a 41-year-old woman, presented with abnormal left eye tearing and left cheek pain. On computed tomography imaging, a tumor that extended to the left orbit was detected in the left cheek. On cytological examination of fine-needle aspiration (FNA) samples, the tumor cells were observed as sheet-like clusters and single bare nuclei with a clear background; peripheral palisading was not clearly seen. On examination of the biopsy specimen taken after FNA, the tumor was found to be composed of cancer cell nests with scattered peripheral palisading in the dermis. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) 7 and CD56 and were negative for CK20, synaptophysin, and chromogranin A. Membrane-bound dense-core granules were detected on ultrastructural study. A HBCC case with neuroendocrine differentiation has not been previously reported. The correlation between the presence of neuroendocrine differentiation in HBCC and patient prognosis should be further studied. PMID:25120472

Kinoshita, Yuichi; Takasu, Kosho; Yoshizawa, Katsuhiko; Emoto, Yuko; Yuki, Michiko; Yuri, Takashi; Shikata, Nobuaki; Tsubura, Airo

2014-01-01

396

Astrocyte-derived nitric oxide in manganese neurotoxicity: from cellular and molecular mechanisms underlying selective neuronal vulnerability in the basal ganglia to potential therapeutic modalities  

E-print Network

to MnCl2 (100 mg/kg/day) by oral gavage daily for 8 weeks. After the experiment striatal dopamine (DA) content was decreased with the manifestation of hypoactivity. A distinct population of neurons was vulnerable to the effects of Mn, including...

Liu, Xuhong

2007-04-25

397

Tritium-3-N-methylspiperone labels D2 dopamine receptors in basal ganglia and S2 serotonin receptors in cerebral cortex  

SciTech Connect

Detailed studies of the properties of /sup 3/H-3-N-methylspiperone (NMSP) binding in rat and human brain homogenates were performed at 37/sup 0/C. In homogenates of rat striatum and frontal cortex and human caudate and frontal cortex tissues, the specific binding was found to be saturable. Rat caudate contained 33.2 pmol/gm wet-weight tissue and displayed an equilibrium dissociation constant (Kd) of 8.7 X 10(-11) M; rat frontal cortex contained 18.5 pmol/gm wet-weight tissue and displayed a Kd of 1.5 X 10(-10) M. Human caudate contained 8.96 pmol/gm wet-weight tissue and displayed a Kd of 1.1 X 10(-10) M; human frontal cortex possessed 9.8 pmol/gm wet-weight tissue and a Kd of 4.4 X 10(-10) M. Kinetic studies revealed a very rapid rate of association in all the tissues studied. The rate of dissociation was relatively slow in all 4 tissue preparations; the dissociation rate was somewhat slower in rat striatum and human caudate relative to rat and human frontal cortex. This was consistent with the somewhat higher affinity, relative to frontal cortex, displayed by /sup 3/H-NMSP in rat striatal and human caudate tissue. The pharmacological properties of the specific binding in rat striatal and human caudate tissues were very similar and indicated the presence of brain D2 dopamine receptors. In rat and human frontal cortex tissue homogenates, the pharmacological characteristics of the specific binding indicated the presence of 5-HT2 receptors.

Lyon, R.A.; Titeler, M.; Frost, J.J.; Whitehouse, P.J.; Wong, D.F.; Wagner, H.N. Jr.; Dannals, R.F.; Links, J.M.; Kuhar, M.J.

1986-10-01

398

The Basal Ganglia as a Structure of Vocal Sensory-Motor Integration and Modulation of Vocal Plasticity in Mammals: Behavioral and Experimental Evidence from Tadarida brasiliensis  

E-print Network

et al., 1978; Bates et al., 2008). Also, echolocating bats constantly adjust pulse durations to suit the range of the current target or background distances and in response to noise (Simmons and Grinnell, 1988). Big brown bats (Eptesicus fuscus... et al., 1978; Bates et al., 2008). Also, echolocating bats constantly adjust pulse durations to suit the range of the current target or background distances and in response to noise (Simmons and Grinnell, 1988). Big brown bats (Eptesicus fuscus...

Tressler, Jedediah Tim

2012-02-14

399

Auditory observation of infant-directed speech by mothers: experience-dependent interaction between language and emotion in the basal ganglia  

PubMed Central

Adults address infants with a special speech register known as infant-directed speech (IDS), which conveys both linguistic and emotional information through its characteristic lexicon and exaggerated prosody (e.g., higher pitched, slower, and hyperarticulated). Although caregivers are known to regulate the usage of IDS (linguistic and emotional components) depending on their childs development, the underlying neural substrates of this flexible modification are largely unknown. Here, using an auditory observation method and functional magnetic resonance imaging (fMRI) of four different groups of females, we revealed the experience-dependent influence of the emotional component on linguistic processing in the right caudate nucleus when mothers process IDS: (1) non-mothers, who do not use IDS regularly, showed no significant difference between IDS and adult-directed speech (ADS); (2) mothers with preverbal infants, who primarily use the emotional component of IDS, showed the main effect of the emotional component of IDS; (3) mothers with toddlers at the two-word stage, who use both linguistic and emotional components of IDS, showed an interaction between the linguistic and emotional components of IDS; and (4) mothers with school-age children, who use ADS rather than IDS toward their children, showed a tendency toward the main effect of ADS. The task that was most comparable to the naturalistic categories of IDS (i.e., explicit-language and implicit-emotion processing) recruited the right caudate nucleus, but it was not recruited in the control, less naturalistic condition (explicit-emotion and implicit-language processing). Our results indicate that the right caudate nucleus processes experience-and task-dependent interactions between language and emotion in mothers IDS.

Matsuda, Yoshi-Taka; Ueno, Kenichi; Cheng, Kang; Konishi, Yukuo; Mazuka, Reiko; Okanoya, Kazuo

2014-01-01

400

Role of high-field intraoperative magnetic resonance imaging on a multi-image fusion-guided stereotactic biopsy of the basal ganglia: A case report  

PubMed Central

The aim of the present case study was to investigate the advantages of intraoperative magnetic resonance imaging (iMRI) on the real-time guidance and monitoring of a stereotactic biopsy. The study describes a patient with intracranial lesions, which were examined by conventional MRI and diffusion tensor imaging using a 1.5T intraoperative MRI system. The digital and pre-operative positron emission/computed tomography image data were transferred to a BrainLAB planning workstation, and a variety of images were automatically fused. The BrainLAB software was then used to reconstruct the corticospinal tract (CST) and create a three-dimensional display of the anatomical association between the CST and the brain lesions. A Leksell surgical planning workstation was used to identify the ideal target site and a reasonable needle track for the biopsy. The 1.5T iMRI was used to effectively monitor the intracranial condition during the brain biopsy procedure. Post-operatively, the original symptoms of the patient were not aggravated and no further neurological deficits were apparent. The histopathological diagnosis of non-Hodgkins B-cell lymphoma was made. Using high-field iMRI, the multi-image fusion-guided stereotactic brain biopsy allows for a higher positive rate of biopsy and a lower incidence of complications. The approach of combining multi-image fusion images with the frame-based stereotactic biopsy may be clinically useful for intracranial lesions of deep functional areas.

SUN, XIANG; CHEN, ZHIJUAN; YANG, SHUYUAN; ZHANG, JIANNING; YUE, SHUYUAN; WANG, ZENGGUANG; YANG, WEIDONG

2015-01-01

401

Ectopic expression of TrKA in the adult rat basal ganglia induces both nerve growth factor-dependent and -independent neuronal responses.  

PubMed

Ectopic expression of tropomyosin-related kinase A (TrkA), the high-affinity receptor of nerve growth factor (NGF), has been widely used in cell culture systems to uncover its role in cell survival or death events. In contrast, little is known about the consequences of its expression in vivo. To address this question, adeno-associated virus (AAV) vectors were used to express TrkA in the substantia nigra (SN) and striatum of adult rats. Nine weeks after transfer, tyrosine hydroxylase (TH) and dopamine transporter (DAT) mRNAs were slightly decreased in the ipsilateral SN. This decrease was no longer significant when NGF was delivered into the striatum. There was no change of DAT binding sites or D1 or D2 receptor mRNAs and binding sites in the striatum, suggesting that ectopic TrkA exerts a limited effect on the pool of TH and DAT transcripts, without affecting overall dopamine signaling. When transferred into the striatum, TrkA transgene had no effect on the size of the cholinergic interneurons, but it exerted typical neurotrophic effects, as shown by an enlargement of the projection neurons and nitric oxide synthase (nNOS)-expressing interneurons. This trophic action was amplified by a delivery of NGF. No toxic effect of the transgene was noted. These data indicate that ectopic expression of TrkA may result in the promotion of neurotrophic effects or can influence neuronal plasticity in the absence of exogenous NGF in neuronal populations that naturally fail to respond to this factor. PMID:22419059

Giannakopoulou, Dimitra; Daguin-Nerrire, Vronique; Mitsacos, Adamantia; Kouvelas, Elias D; Neveu, Isabelle; Giompres, Panagiotis; Brachet, Philippe

2012-08-01

402

The tonic\\/phasic model of dopamine system regulation: its relevance for understanding how stimulant abuse can alter basal ganglia function  

Microsoft Academic Search

The changes in dopamine system regulation occurring during stimulant administration are examined in relation to a new model of dopamine system function. This model is based on the presence of a tonic low level of extracellular dopamine that is released by the presynaptic action of corticostriatal afferents. In contrast, spike-dependent dopamine release results in a phasic, high concentration of dopamine

Anthony A. Grace

1995-01-01

403

[Hematological abnormalities in rheumatic diseases].  

PubMed

Haematological abnormalities are present in 25-50% patients with rheumatic diseases. The most common finding is anaemia of chronic disease which is driven by inflammatory cytokines. Hepcidin plays key role in iron homeostasis. It reduces iron absorption from duodenum and iron release from reticuloendothelial cells. Anaemia of chronic disease could be successfully treated by recombinant erythropoietin in combination with iron supplementation. Various abnormalities can be observed in the leukocyte and platelets counts. Other haematological disturbances are considered as part of autoimmune disease. Prolonged antigen stimulation can induce lymphomagenesis and lymphoma incidence in patients with rheumatic diseases is 5 to 6-fold increased compared to normal population. PMID:17580549

Radman, Ivo

2006-01-01

404

Effects of dopamine depletion on LFP oscillations in striatum are task- and learning-dependent and selectively reversed by l-DOPA  

E-print Network

A major physiologic sign in Parkinson disease is the occurrence of abnormal oscillations in cortico-basal ganglia circuits, which can be normalized by l-DOPA therapy. Under normal circumstances, oscillatory activity in ...

Lemaire, Nune

405

Abnormal Psychology, Spring 2008 1 Psychology 350  

E-print Network

Abnormal Psychology, Spring 2008 1 Psychology 350 Abnormal Psychology Spring 2008 N-101 Tuesdays 4 psychology. By the end of the semester, students will be able to: · Discuss extant models of abnormal in Foundation II.B., Social and Behavioral Sciences required." #12;Abnormal Psychology, Spring 2008 2 Course

Gallo, Linda C.

406

Abnormalities of human sex determination  

Microsoft Academic Search

Summary Cytogenetic and molecular studies in patients with abnormalities of sex determination have been the key to the isolation and investigation of candidates for the primary testis determining factor (TDF). A gene, SRY, isolated from the sex determining region of the Y chromosome within 5 kilobases of the pairing segment boundary, has been characterized recently which fulfils the expectations of

M. A. Ferguson-Smith

1992-01-01

407

Steganography with Least Histogram Abnormality  

Microsoft Academic Search

A novel steganographic scheme is proposed which avoids asymmetry inherent in conventional LSB embedding techniques so that abnormality in the image histogram is kept minimum. The proposed technique is capable of re- sisting the ?2 test and RS analysis, as well as a new steganalytic method named GPC analysis as introduced in this paper. In the described steganographic tech- nique,

Xinpeng Zhang; Shuozhong Wang; Kaiwen Zhang

2003-01-01

408

Extracellular Matrix Abnormalities in Schizophrenia  

PubMed Central

Emerging evidence points to the involvement of the brain extracellular matrix (ECM) in the pathophysiology of schizophrenia (SZ). Abnormalities affecting several ECM components, including Reelin and chondroitin sulfate proteoglycans (CSPGs), have been described in subjects with this disease. Solid evidence supports the involvement of Reelin, an ECM glycoprotein involved in corticogenesis, synaptic functions and glutamate NMDA receptor regulation, expressed prevalently in distinct populations of GABAergic neurons, which secrete it into the ECM. Marked changes of Reelin expression in SZ have typically been reported in association with GABA-related abnormalities in subjects with SZ and bipolar disorder. Recent findings from our group point to substantial abnormalities affecting CSPGs, a main ECM component, in the amygdala and entorhinal cortex of subjects with schizophrenia, but not bipolar disorder. Striking increases of glial cells expressing CSPGs were accompanied by reductions of perineuronal nets, CSPG- and Reelin-enriched ECM aggregates enveloping distinct neuronal populations. CSPGs developmental and adult functions, including neuronal migration, axon guidance, synaptic and neurotransmission regulation are highly relevant to the pathophysiology of SZ. Together with reports of anomalies affecting several other ECM components, these findings point to the ECM as a key component of the pathology of SZ. We propose that ECM abnormalities may contribute to several aspects of the pathophysiology of this disease, including disrupted connectivity and neuronal migration, synaptic anomalies and altered GABAergic, glutamatergic and dopaminergic neurotransmission. PMID:21856318

Berretta, Sabina

2011-01-01

409

Chronic levodopa treatment alters basal and dopamine agonist-stimulated cerebral glucose utilization  

SciTech Connect

The effect of chronic levodopa administration on the functional activity of the basal ganglia and its output regions was evaluated by means of the 2-deoxyglucose (2-DG) autoradiographic technique in rats with a unilateral 6-hydroxydopamine lesion of the nigrostriatal pathway. The rates of local cerebral glucose utilization were studied under basal conditions as well as in response to challenge with a selective D1 or D2 dopamine-receptor agonist. Levodopa (100 mg/kg/d, i.p.) was administered for 19 d either continuously via infusion with an osmotic pump or intermittently by twice-daily injections. Following a 3-d washout, glucose utilization was found to be decreased by both levodopa regimens in the nucleus accumbens; intermittent levodopa also decreased glucose utilization in the entopeduncular nucleus, subthalamic nucleus, ventrolateral thalamus, ventromedial thalamus, ventroposterolateral thalamus, and lateral habenula. In control (lesioned and treated chronically with saline) rats, the D1 agonist SKF 38393 (5 mg/kg, i.v.) increased 2-DG uptake in the substantia nigra pars reticulata and entopeduncular nucleus ipsilateral to the lesion by 84% and 56%, respectively. Both continuous and intermittent levodopa blunted the SKF 38393-induced elevation in glucose metabolism in the substantia nigra pars reticulata, while intermittent levodopa also attenuated the increase in the entopeduncular nucleus. The D2 agonist quinpirole (0.4 mg/kg, i.v.) did not increase glucose utilization in any brain region in control animals; following intermittent levodopa treatment, however, quinpirole increased 2-DG uptake by 64% in the subthalamic nucleus and by 39% in the deep layers of the superior colliculus on the ipsilateral side.

Engber, T.M.; Susel, Z.; Kuo, S.; Chase, T.N. (National Institute of Neurological Disorders and Stroke, Bethesda, MD (USA))

1990-12-01

410

Food habits and the basal rate of metabolism in birds  

Microsoft Academic Search

The correlation of basal rate of metabolism with various factors is examined in birds. Chief among these is body mass. As in mammals, much of the remaining variation in basal rate among birds is associated with food habits. Birds other than passerines that feed on grass, nectar, flying insects, or vertebrates generally have basal rates that are similar to mammals

Brian K. McNab

1988-01-01

411

Basal cell carcinoma of the perineum.  

PubMed

Basal cell carcinoma (BCC) is the most common nonmelanoma skin cancer. Most BCCs are found on areas of UV-damaged skin, The study of BCCs of sun-protected regions, however, suggests a more complex pathogenesis. We present a case of BCC of the perineum in a man with no previous history of skin cancer. This is the first report of BCC in this region and one of a small body of cases arising on or near the genital and perianal regions. PMID:25148280

Levin, Adriane Ann; Dabade, Tushar; Dandekar, Monisha; Rogers, Gary; Rosmarin, David

2014-08-01

412

Nonsurgical Treatment Options for Basal Cell Carcinoma  

PubMed Central

Basal cell carcinoma (BCC) remains the most common form of nonmelanoma skin cancer (NMSC) in Caucasians, with perhaps as many as 2 million new cases expected to occur in the United States in 2010. Many treatment options, including surgical interventions and nonsurgical alternatives, have been utilized to treat BCC. In this paper, two non-surgical options, imiquimod therapy and photodynamic therapy (PDT), will be discussed. Both modalities have demonstrated acceptable disease control rates, cosmetically superior outcomes, and short-term cost-effectiveness. Further studies evaluating long-term cure rates and long-term cost effectiveness of imiquimod therapy and PDT are needed. PMID:21274437

Lien, Mary H.; Sondak, Vernon K.

2011-01-01

413