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https://www.readbyqxmd.com/read/28633970/unified-neural-field-theory-of-brain-dynamics-underlying-oscillations-in-parkinson-s-disease-and-generalized-epilepsies
#1
E J Müller, S J van Albada, J W Kim, P A Robinson
The mechanisms underlying pathologically synchronized neural oscillations in Parkinson's disease (PD) and generalized epilepsies are explored in parallel via a physiologically-based neural field model of the corticothalamic-basal ganglia (CTBG) system. The basal ganglia (BG) are approximated as a single effective population and their roles in the modulation of oscillatory dynamics of the corticothalamic (CT) system and vice versa are analyzed. In addition to normal EEG rhythms, enhanced activity around 4 Hz and 20 Hz exists in the model, consistent with the characteristic frequencies observed in PD...
June 17, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28592690/dynamics-of-human-subthalamic-neuron-phase-locking-to-motor-and-sensory-cortical-oscillations-during-movement
#2
Witold J Lipski, Thomas A Wozny, Ahmad Alhourani, Efstathios Kondylis, Robert S Turner, Donald J Crammond, Robert Mark Richardson
Coupled oscillatory activity recorded between sensorimotor regions of the basal ganglia-thalamocortical loop is thought to reflect information transfer relevant to movement. A neuronal firing-rate model of basal ganglia-thalamocortical circuitry, however, has dominated thinking about basal ganglia function for the past three decades, without knowledge of the relationship between basal ganglia single neuron firing and cortical population activity during movement itself. We recorded activity from 34 subthalamic nucleus (STN) neurons, simultaneously with cortical local field potentials and motor output, in eleven subjects with Parkinson's disease (PD) undergoing awake deep brain stimulator lead placement...
June 7, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28541214/investigating-synchronous-oscillation-and-deep-brain-stimulation-treatment-in-a-model-of-cortico-basal-ganglia-network
#3
Meili Lu, Xile Wei, Kenneth A Loparo
Altered firing properties and increased pathological oscillations in the basal ganglia have been proven to be hallmarks of Parkinson's disease. Increasing evidence suggests that abnormal synchronous oscillations and suppression in the cortex may also play a critical role in the pathogenic process and treatment of Parkinson's disease. In our study, a new closed-loop network including the cortex and basal ganglia using the Izhikevich models is proposed to investigate the synchrony and pathological oscillations in motor circuits and their modulation by deep brain stimulation (DBS)...
May 23, 2017: IEEE Transactions on Neural Systems and Rehabilitation Engineering
https://www.readbyqxmd.com/read/28468999/ketamine-induced-converged-synchronous-gamma-oscillations-in-the-cortico-basal-ganglia-network-of-non-human-primates
#4
Maya Slovik, Boris Rosin, Shay Moshel, Rea Mitelman, Eitan Schechtman, Renana Eitan, Aeyal Raz, Hagai Bergman
NMDA (N-methyl-D-aspartate) antagonists are widely used in anesthesia, pain management, schizophrenia animal model studies and recently as potential antidepressants. However the mechanisms underlying their anesthetic, psychotic, cognitive and emotional effects are still elusive. The basal-ganglia (BG) integrate input from different cortical domains through its dopamine modulated connections, to achieve optimal behavior control. NMDA antagonists have been shown to induce gamma oscillations in human EEG recordings and in rodents cortical and BG networks...
May 3, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28465167/the-neural-basis-of-delay-discounting-a-review-and-preliminary-model
#5
REVIEW
Ralph Frost, Neil McNaughton
The phenomenology of delay discounting (e.g. shape of the discount function; relation to mental health) has been reviewed in detail previously, but not its neural substrates. Its neuropsychology is crucial for both theory and clinical practice. So, here, we review the neural underpinnings of delay discounting. We introduce its objective summary measures; provide an atheoretical summary of current findings - linking brain regions to each objectively measurable variable; and then provide a preliminary five-stage summary model of cognitive processing; followed by a mapping of parameters to the flow of information through neural systems...
August 2017: Neuroscience and Biobehavioral Reviews
https://www.readbyqxmd.com/read/28454042/cortical-plasticity-and-levodopa-induced-dyskinesias-in-parkinson-s-disease-connecting-the-dots-in-a-multicomponent-network
#6
REVIEW
Roopa Rajan, Traian Popa, Angelo Quartarone, Maria Felice Ghilardi, Asha Kishore
Levodopa-induced dyskinesias are motor complications following long term dopaminergic therapy in Parkinson's disease (PD). Impaired brain plasticity resulting in the creation of aberrant motor maps intended to encode normal voluntary movement is proposed to result in the development of dyskinesias. Traditionally, the various nodes in the motor network like the striato-cortical and the cerebello-thalamic loops were thought to function independent of each other with little communication among them. Anatomical evidence from primates revealed the existence of reciprocal loops between the basal ganglia and the cerebellum providing an anatomical basis for communication between the motor network loops...
June 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28334424/frequency-and-function-in-the-basal-ganglia-the-origins-of-beta-and-gamma-band-activity
#7
Alexander Blenkinsop, Sean Anderson, Kevin Gurney
KEY POINTS: Neuronal oscillations in the basal ganglia have been observed to correlate with behaviours, although the causal mechanisms and functional significance of these oscillations remain unknown. We present a novel computational model of the healthy basal ganglia, constrained by single unit recordings from non-human primates. When the model is run using inputs that might be expected during performance of a motor task, the network shows emergent phenomena: it functions as a selection mechanism and shows spectral properties that match those seen in vivo...
March 23, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28326032/a-dynamic-circuit-hypothesis-for-the-pathogenesis-of-blepharospasm
#8
David A Peterson, Terrence J Sejnowski
Blepharospasm (sometimes called "benign essential blepharospasm," BEB) is one of the most common focal dystonias. It involves involuntary eyelid spasms, eye closure, and increased blinking. Despite the success of botulinum toxin injections and, in some cases, pharmacologic or surgical interventions, BEB treatments are not completely efficacious and only symptomatic. We could develop principled strategies for preventing and reversing the disease if we knew the pathogenesis of primary BEB. The objective of this study was to develop a conceptual framework and dynamic circuit hypothesis for the pathogenesis of BEB...
2017: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/28303790/design-of-robust-adaptive-controller-and-feedback-error-learning-for-rehabilitation-in-parkinson-s-disease-a-simulation-study
#9
Korosh Rouhollahi, Mehran Emadi Andani, Seyed Mahdi Karbassi, Iman Izadi
Deep brain stimulation (DBS) is an efficient therapy to control movement disorders of Parkinson's tremor. Stimulation of one area of basal ganglia (BG) by DBS with no feedback is the prevalent opinion. Reduction of additional stimulatory signal delivered to the brain is the advantage of using feedback. This results in reduction of side effects caused by the excessive stimulation intensity. In fact, the stimulatory intensity of controllers is decreased proportional to reduction of hand tremor. The objective of this study is to design a new controller structure to decrease three indicators: (i) the hand tremor; (ii) the level of delivered stimulation in disease condition; and (iii) the ratio of the level of delivered stimulation in health condition to disease condition...
February 2017: IET Systems Biology
https://www.readbyqxmd.com/read/28269579/development-of-semi-chronic-microdrive-system-for-large-scale-circuit-mapping-in-macaque-mesolimbic-and-basal-ganglia-systems
#10
Shaoyu Qiao, Kevin A Brown, Amy L Orsborn, Breonna Ferrentino, Bijan Pesaran
The development of novel neurotechnologies for treating refractory neuropsychiatry disorders depends on understanding and manipulating the dynamics of neural circuits across large-scale brain networks. The mesolimbic pathway plays an essential role in reward processing and mood regulation and disorders of this pathway underlie many neuropsychiatric disorders. Here, we present the design of a customized semi-chronic microdrive array that precisely targets the anatomical structures of non-human primate (NHP) mesolimbic and basal ganglia systems...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227834/development-of-semi-chronic-microdrive-system-for-large-scale-circuit-mapping-in-macaque-mesolimbic-and-basal-ganglia-systems
#11
Shaoyu Qiao, Kevin A Brown, Amy L Orsborn, Breonna Ferrentino, Bijan Pesaran, Shaoyu Qiao, Kevin A Brown, Amy L Orsborn, Breonna Ferrentino, Bijan Pesaran, Shaoyu Qiao, Amy L Orsborn, Breonna Ferrentino, Kevin A Brown, Bijan Pesaran
The development of novel neurotechnologies for treating refractory neuropsychiatry disorders depends on understanding and manipulating the dynamics of neural circuits across large-scale brain networks. The mesolimbic pathway plays an essential role in reward processing and mood regulation and disorders of this pathway underlie many neuropsychiatric disorders. Here, we present the design of a customized semi-chronic microdrive array that precisely targets the anatomical structures of non-human primate (NHP) mesolimbic and basal ganglia systems...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28192762/neural-mass-models-describing-possible-origin-of-the-excessive-beta-oscillations-correlated-with-parkinsonian-state
#12
Chen Liu, Yulin Zhu, Fei Liu, Jiang Wang, Huiyan Li, Bin Deng, Chris Fietkiewicz, Kenneth A Loparo
In Parkinson's disease, the enhanced beta rhythm is closely associated with akinesia/bradykinesia and rigidity. An increase in beta oscillations (12-35 Hz) within the basal ganglia (BG) nuclei does not proliferate throughout the cortico-basal ganglia loop in uniform fashion; rather it can be subdivided into two distinct frequency bands, i.e. the lower beta (12-20 Hz) and upper beta (21-35 Hz). A computational model of the excitatory and inhibitory neural network that focuses on the population properties is proposed to explore the mechanism underlying the pathological beta oscillations...
April 2017: Neural Networks: the Official Journal of the International Neural Network Society
https://www.readbyqxmd.com/read/28186664/disruption-in-cerebellar-and-basal-ganglia-networks-during-a-visuospatial-task-in-cervical-dystonia
#13
Pavel Filip, Cécile Gallea, Stéphane Lehéricy, Eric Bertasi, Traian Popa, Radek Mareček, Ovidiu V Lungu, Tomáš Kašpárek, Jiří Vaníček, Martin Bareš
BACKGROUND: Although dystonia is traditionally conceptualized as a basal ganglia disorder, increasing interest has been directed at a different neural network node, the cerebellum, which may play a significant role in the pathophysiology of dystonia. Abnormal sensorimotor processing and disturbed motor schemes, possibly attributable to cerebellar changes, remain unclear. METHODS: We sought to characterize the extent of cerebellar dysfunction within the motor network using functional MRI activation analysis, connectivity analysis, and voxel-based morphometry in cervical dystonia patients (n = 25, 15 women, mean age 45...
February 10, 2017: Movement Disorders: Official Journal of the Movement Disorder Society
https://www.readbyqxmd.com/read/28127519/increased-thalamic-centrality-and-putamen-thalamic-connectivity-in-patients-with-parkinsonian-resting-tremor
#14
Quanquan Gu, Hengyi Cao, Min Xuan, Wei Luo, Xiaojun Guan, Jingjing Xu, Peiyu Huang, Minming Zhang, Xiaojun Xu
INTRODUCTION: Evidence has indicated a strong association between hyperactivity in the cerebello-thalamo-motor cortical loop and resting tremor in Parkinson's disease (PD). Within this loop, the thalamus serves as a central hub based on its structural centrality in the generation of resting tremor. To study whether this thalamic abnormality leads to an alteration at the whole-brain level, our study investigated the role of the thalamus in patients with parkinsonian resting tremor in a large-scale brain network context...
January 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28065671/glutamine-triggers-long-lasting-increase-in-striatal-network-activity-in-vitro
#15
Wiebke Fleischer, Stephan Theiss, Alfons Schnitzler, Olga Sergeeva
Accumulation of ammonium and glutamine in blood and brain is a key factor in hepatic encephalopathy (HE) - a neuropsychiatric syndrome characterized by various cognitive and motor deficits. MRI imaging identified abnormalities notably in the basal ganglia of HE patients, including its major input station, the striatum. While neurotoxic effects of ammonia have been extensively studied, glutamine is primarily perceived as "detoxified" form of ammonia. We applied ammonium and glutamine to striatal and cortical cells from newborn rats cultured on microelectrode arrays...
April 2017: Experimental Neurology
https://www.readbyqxmd.com/read/28062203/semi-mechanistic-computer-simulation-of-psychotic-symptoms-in-schizophrenia-with-a-model-of-a-humanized-cortico-striatal-thalamocortical-loop
#16
Athan Spiros, Patrick Roberts, Hugo Geerts
Despite new insights into the pathophysiology of schizophrenia and clinical trials with highly selective drugs, no new therapeutic breakthroughs have been identified. We present a semi-mechanistic Quantitative Systems Pharmacology (QSP) computer model of a biophysically realistic cortical-striatal-thalamo-cortical loop. The model incorporates the direct, indirect and hyperdirect pathway of the basal ganglia and CNS drug targets that modulate neuronal firing, based on preclinical data about their localization and coupling to voltage-gated ion channels...
February 2017: European Neuropsychopharmacology: the Journal of the European College of Neuropsychopharmacology
https://www.readbyqxmd.com/read/28019687/improving-with-practice-a-neural-model-of-mathematical-development
#17
Sean Aubin, Aaron R Voelker, Chris Eliasmith
The ability to improve in speed and accuracy as a result of repeating some task is an important hallmark of intelligent biological systems. Although gradual behavioral improvements from practice have been modeled in spiking neural networks, few such models have attempted to explain cognitive development of a task as complex as addition. In this work, we model the progression from a counting-based strategy for addition to a recall-based strategy. The model consists of two networks working in parallel: a slower basal ganglia loop and a faster cortical network...
December 26, 2016: Topics in Cognitive Science
https://www.readbyqxmd.com/read/28018194/cross-sectional-and-longitudinal-relationships-between-depressive-symptoms-and-brain-atrophy-in-ms-patients
#18
Heiner Stuke, Katrin Hanken, Jochen Hirsch, Jan Klein, Fabian Wittig, Andreas Kastrup, Helmut Hildebrandt
Introduction: Depressive symptoms are a frequent and distressing phenomenon in Multiple Sclerosis (MS) patients. Cross-sectional research links these symptoms to reduced brain gray matter volumes in parts of the prefrontal and temporal lobe as well as subcortical structures like the hippocampus, nucleus caudatus and globus pallidus. Nevertheless, prospective relationships between regional gray matter volume and the course of depressive symptoms are poorly understood. Methods: Forty-four patients with relapsing-remitting or secondary progressive MS participated in a prospective study with two assessments of depressive symptoms and high-resolution MRI with an inter-test-interval of 17 months...
2016: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28002987/decision-making-under-uncertainty-in-a-spiking-neural-network-model-of-the-basal-ganglia
#19
Charlotte Héricé, Radwa Khalil, Marie Moftah, Thomas Boraud, Martin Guthrie, André Garenne
The mechanisms of decision-making and action selection are generally thought to be under the control of parallel cortico-subcortical loops connecting back to distinct areas of cortex through the basal ganglia and processing motor, cognitive and limbic modalities of decision-making. We have used these properties to develop and extend a connectionist model at a spiking neuron level based on a previous rate model approach. This model is demonstrated on decision-making tasks that have been studied in primates and the electrophysiology interpreted to show that the decision is made in two steps...
December 2016: Journal of Integrative Neuroscience
https://www.readbyqxmd.com/read/27989846/cortical-areas-involved-in-behavioral-expression-of-external-pallidum-dysfunctions-a-pet-imaging-study-in-non-human-primates
#20
Laurent Galineau, Aurélie Kas, Yulia Worbe, Marion Chaigneau, Anne-Sophie Herard, Martine Guillermier, Thierry Delzescaux, Jean Féger, Philippe Hantraye, Léon Tremblay
The external pallidum (GPe) is a component of the indirect pathway centrally placed in the basal ganglia. Studies already demonstrated that the pharmacological disinhibition of the sensorimotor, associative, and limbic GPe produced dyskinesia, hyperactivity, and compulsive behaviors, respectively. The aim of this study was to investigate the cortical regions altered by the disinhibition of each GPe functional territory. Thus, 5 macaques were injected with bicuculline in sensorimotor, associative, and limbic sites of the GPe producing dyskinesia, hyperactivity, and compulsive behaviors, and underwent in vivo positron tomography with (18)F-2-fluoro-2-deoxy-D-glucose to identify cortical dysfunctions related to GPe disinhibition...
February 1, 2017: NeuroImage
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