keyword
MENU ▼
Read by QxMD icon Read
search

loops of the basal ganglia

keyword
https://www.readbyqxmd.com/read/28065671/glutamine-triggers-long-lasting-increase-in-striatal-network-activity-in-vitro
#1
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...
January 6, 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
#2
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...
January 3, 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
#3
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
#4
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
#5
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 21, 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
#6
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...
October 28, 2016: NeuroImage
https://www.readbyqxmd.com/read/27923040/a-low-correlation-resting-state-of-the-striatum-during-cortical-avalanches-and-its-role-in-movement-suppression
#7
Andreas Klaus, Dietmar Plenz
During quiet resting behavior, involuntary movements are suppressed. Such movement control is attributed to cortico-basal ganglia loops, yet population dynamics within these loops during resting and their relation to involuntary movements are not well characterized. Here, we show by recording cortical and striatal ongoing population activity in awake rats during quiet resting that intrastriatal inhibition maintains a low-correlation striatal resting state in the presence of cortical neuronal avalanches. Involuntary movements arise from disturbed striatal resting activity through two different population dynamics...
December 2016: PLoS Biology
https://www.readbyqxmd.com/read/27917146/a-unified-theoretical-framework-for-cognitive-sequencing
#8
Tejas Savalia, Anuj Shukla, Raju S Bapi
The capacity to sequence information is central to human performance. Sequencing ability forms the foundation stone for higher order cognition related to language and goal-directed planning. Information related to the order of items, their timing, chunking and hierarchical organization are important aspects in sequencing. Past research on sequencing has emphasized two distinct and independent dichotomies: implicit vs. explicit and goal-directed vs. habits. We propose a theoretical framework unifying these two streams...
2016: Frontiers in Psychology
https://www.readbyqxmd.com/read/27892854/a-comprehensive-excitatory-input-map-of-the-striatum-reveals-novel-functional-organization
#9
Barbara J Hunnicutt, Bart C Jongbloets, William T Birdsong, Katrina J Gertz, Haining Zhong, Tianyi Mao
The striatum integrates excitatory inputs from the cortex and the thalamus to control diverse functions. Although the striatum is thought to consist of sensorimotor, associative and limbic domains, their precise demarcations and whether additional functional subdivisions exist remain unclear. How striatal inputs are differentially segregated into each domain is also poorly understood. This study presents a comprehensive map of the excitatory inputs to the mouse striatum. The input patterns reveal boundaries between the known striatal domains...
November 28, 2016: ELife
https://www.readbyqxmd.com/read/27891079/contribution-of-tms-and-rtms-in-the-understanding-of-the-pathophysiology-and-in-the-treatment-of-dystonia
#10
REVIEW
Pierre Lozeron, Aurélia Poujois, Alexandra Richard, Sana Masmoudi, Elodie Meppiel, France Woimant, Nathalie Kubis
Dystonias represent a heterogeneous group of movement disorders responsible for sustained muscle contraction, abnormal postures, and muscle twists. It can affect focal or segmental body parts or be generalized. Primary dystonia is the most common form of dystonia but it can also be secondary to metabolic or structural dysfunction, the consequence of a drug's side-effect or of genetic origin. The pathophysiology is still not elucidated. Based on lesion studies, dystonia has been regarded as a pure motor dysfunction of the basal ganglia loop...
2016: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/27889469/changes-in-neural-circuitry-associated-with-depression-at-pre-clinical-pre-motor-and-early-motor-phases-of-parkinson-s-disease
#11
REVIEW
Janina Borgonovo, Camilo Allende-Castro, Almudena Laliena, Néstor Guerrero, Hernán Silva, Miguel L Concha
Although Parkinson's Disease (PD) is mostly considered a motor disorder, it can present at early stages as a non-motor pathology. Among the non-motor clinical manifestations, depression shows a high prevalence and can be one of the first clinical signs to appear, even a decade before the onset of motor symptoms. Here, we review the evidence of early dysfunction in neural circuitry associated with depression in the context of PD, focusing on pre-clinical, pre-motor and early motor phases of the disease. In the pre-clinical phase, structural and functional changes in the substantia nigra, basal ganglia and limbic structures are already observed...
November 21, 2016: Parkinsonism & related Disorders
https://www.readbyqxmd.com/read/27872585/the-pedunculopontine-tegmental-nucleus-as-a-motor-and-cognitive-interface-between-the-cerebellum-and-basal-ganglia
#12
REVIEW
Fumika Mori, Ken-Ichi Okada, Taishin Nomura, Yasushi Kobayashi
As an important component of ascending activating systems, brainstem cholinergic neurons in the pedunculopontine tegmental nucleus (PPTg) are involved in the regulation of motor control (locomotion, posture and gaze) and cognitive processes (attention, learning and memory). The PPTg is highly interconnected with several regions of the basal ganglia, and one of its key functions is to regulate and relay activity from the basal ganglia. Together, they have been implicated in the motor control system (such as voluntary movement initiation or inhibition), and modulate aspects of executive function (such as motivation)...
2016: Frontiers in Neuroanatomy
https://www.readbyqxmd.com/read/27866799/inhibitory-control-in-the-cortico-basal-ganglia-thalamocortical-loop-complex-regulation-and-interplay-with-memory-and-decision-processes
#13
Wei Wei, Xiao-Jing Wang
We developed a circuit model of spiking neurons that includes multiple pathways in the basal ganglia (BG) and is endowed with feedback mechanisms at three levels: cortical microcircuit, corticothalamic loop, and cortico-BG-thalamocortical system. We focused on executive control in a stop signal task, which is known to depend on BG across species. The model reproduces a range of experimental observations and shows that the newly discovered feedback projection from external globus pallidus to striatum is crucial for inhibitory control...
December 7, 2016: Neuron
https://www.readbyqxmd.com/read/27852016/-neuroanatomy-of-frontal-association-cortex
#14
Masahiko Takada
The frontal association cortex is composed of the prefrontal cortex and the motor-related areas except the primary motor cortex (i.e., the so-called higher motor areas), and is well-developed in primates, including humans. The prefrontal cortex receives and integrates large bits of diverse information from the parietal, temporal, and occipital association cortical areas (termed the posterior association cortex), and paralimbic association cortical areas. This information is then transmitted to the primary motor cortex via multiple motor-related areas...
November 2016: Brain and Nerve, Shinkei Kenkyū No Shinpo
https://www.readbyqxmd.com/read/27803652/goal-directed-behavior-and-instrumental-devaluation-a-neural-system-level-computational-model
#15
Francesco Mannella, Marco Mirolli, Gianluca Baldassarre
Devaluation is the key experimental paradigm used to demonstrate the presence of instrumental behaviors guided by goals in mammals. We propose a neural system-level computational model to address the question of which brain mechanisms allow the current value of rewards to control instrumental actions. The model pivots on and shows the computational soundness of the hypothesis for which the internal representation of instrumental manipulanda (e.g., levers) activate the representation of rewards (or "action-outcomes", e...
2016: Frontiers in Behavioral Neuroscience
https://www.readbyqxmd.com/read/27754484/modulation-of-motor-inhibition-by-subthalamic-stimulation-in-obsessive-compulsive-disorder
#16
A Kibleur, G Gras-Combe, D Benis, J Bastin, T Bougerol, S Chabardès, M Polosan, O David
High-frequency deep brain stimulation of the subthalamic nucleus can be used to treat severe obsessive-compulsive disorders that are refractory to conventional treatments. The mechanisms of action of this approach possibly rely on the modulation of associative-limbic subcortical-cortical loops, but remain to be fully elucidated. Here in 12 patients, we report the effects of high-frequency stimulation of the subthalamic nucleus on behavior, and on electroencephalographic responses and inferred effective connectivity during motor inhibition processes involved in the stop signal task...
October 18, 2016: Translational Psychiatry
https://www.readbyqxmd.com/read/27746043/brain-activity-in-patients-with-adductor-spasmodic-dysphonia-detected-by-functional-magnetic-resonance-imaging
#17
Asanori Kiyuna, Norimoto Kise, Munehisa Hiratsuka, Shunsuke Kondo, Takayuki Uehara, Hiroyuki Maeda, Akira Ganaha, Mikio Suzuki
OBJECTIVES: Spasmodic dysphonia (SD) is considered a focal dystonia. However, the detailed pathophysiology of SD remains unclear, despite the detection of abnormal activity in several brain regions. The aim of this study was to clarify the pathophysiological background of SD. STUDY DESIGN: This is a case-control study. METHODS: Both task-related brain activity measured by functional magnetic resonance imaging by reading the five-digit numbers and resting-state functional connectivity (FC) measured by 150 T2-weighted echo planar images acquired without any task were investigated in 12 patients with adductor SD and in 16 healthy controls...
October 13, 2016: Journal of Voice: Official Journal of the Voice Foundation
https://www.readbyqxmd.com/read/27743915/short-and-long-term-dopamine-depletion-causes-enhanced-beta-oscillations-in-the-cortico-basal-ganglia-loop-of-parkinsonian-rats
#18
Maximilian H Beck, Jens K Haumesser, Johanna Kühn, Jennifer Altschüler, Andrea A Kühn, Christoph van Riesen
Abnormally enhanced beta oscillations have been found in deep brain recordings from human Parkinson's disease (PD) patients and in animal models of PD. Recent correlative evidence suggests that beta oscillations are related to disease-specific symptoms such as akinesia and rigidity. However, this hypothesis has also been repeatedly questioned by studies showing no changes in beta power in animal models using an acute pharmacologic dopamine blockade. To further investigate the temporal dynamics of exaggerated beta synchrony in PD, we investigated the reserpine model, which is characterized by an acute and stable disruption of dopamine transmission, and compared it to the chronic progressive 6-hydroxydopamine (6-OHDA) model...
October 12, 2016: Experimental Neurology
https://www.readbyqxmd.com/read/27651148/striatal-dopamine-modulates-timing-of-self-initiated-saccades
#19
Jun Kunimatsu, Masaki Tanaka
The ability to adjust movement timing is essential in daily life. Explorations of the underlying neural mechanisms have reported a gradual increase or decrease in neuronal activity prior to self-timed movements within the cortico-basal ganglia loop. Previous studies in both humans and animals have shown that endogenous dopamine (DA) plays a modulatory role in self-timing. However, the specific site of dopaminergic regulation remains elusive because the systemic application of DA-related substances can directly alter both cortical and subcortical neuronal activities...
September 17, 2016: Neuroscience
https://www.readbyqxmd.com/read/27538603/electrophysiological-assessment-of-nociception-in-patients-with-parkinson-s-disease-a-multi-methods-approach
#20
Janosch A Priebe, Miriam Kunz, Christian Morcinek, Peter Rieckmann, Stefan Lautenbacher
OBJECTIVE: Nociceptive abnormalities indicating increased pain sensitivity have been reported in patients with Parkinson's disease (PD). The disturbances are mostly responsive to dopaminergic (DA) treatment; yet, there are conflicting results. The objective of the present study was to investigate pain processing and nociception in PD patients in a more comprehensive manner than previous studies. For this purpose, a multi-methods approach was used in order to monitor different levels of the central nervous system (spinal, subcortical-vegetative, cortical)...
September 15, 2016: Journal of the Neurological Sciences
keyword
keyword
10580
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"