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loops of the basal ganglia

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
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
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
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
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
Chunyang Jin, Ann M Decker, Danni L Harris, Bruce E Blough
GPR88, an orphan receptor richly expressed in the striatum, is implicated in a number of basal ganglia-associated disorders. In order to elucidate the functions of GPR88, an in vivo probe appropriate for CNS investigation is required. We previously reported that 2-PCCA was able to modulate GPR88-mediated cAMP production through a Gαi-coupled pathway. Early structure-activity relationship (SAR) studies suggested that the aniline moiety of 2-PCCA is a suitable site for diverse modifications. Aimed at elucidating structural requirements in this region, we have designed and synthesized a series of analogues bearing a variety of substituents at the phenyl ring of the aniline moiety...
August 6, 2016: ACS Chemical Neuroscience
Pierre Berthet, Mikael Lindahl, Philip J Tully, Jeanette Hellgren-Kotaleski, Anders Lansner
The brain enables animals to behaviorally adapt in order to survive in a complex and dynamic environment, but how reward-oriented behaviors are achieved and computed by its underlying neural circuitry is an open question. To address this concern, we have developed a spiking model of the basal ganglia (BG) that learns to dis-inhibit the action leading to a reward despite ongoing changes in the reward schedule. The architecture of the network features the two pathways commonly described in BG, the direct (denoted D1) and the indirect (denoted D2) pathway, as well as a loop involving striatum and the dopaminergic system...
2016: Frontiers in Neural Circuits
Chao-Yan Ou, Yi-Ni Luo, Sheng-Nan He, Xiang-Fa Deng, Hai-Lan Luo, Zong-Xiang Yuan, Hao-Yang Meng, Yu-Huan Mo, Shao-Jun Li, Yue-Ming Jiang
Excessive intake of manganese (Mn) may cause neurotoxicity. Sodium para-aminosalicylic acid (PAS-Na) has been used successfully in the treatment of Mn-induced neurotoxicity. The γ-aminobutyric acid (GABA) is related with learning and memory abilities. However, the mechanism of PAS-Na on improving Mn-induced behavioral deficits is unclear. The current study was aimed to investigate the effects of PAS-Na on Mn-induced behavioral deficits and the involvement of ultrastructural alterations and γ-aminobutyric acid (GABA) metabolism in the basal ganglia of rats...
August 5, 2016: Biological Trace Element Research
Stewart Shipp
Unidirectional connections from the cortex to the matrix of the corpus striatum initiate the cortico-basal ganglia (BG)-thalamocortical loop, thought to be important in momentary action selection and in longer-term fine tuning of behavioural repertoire; a discrete set of striatal compartments, striosomes, has the complementary role of registering or anticipating reward that shapes corticostriatal plasticity. Re-entrant signals traversing the cortico-BG loop impact predominantly frontal cortices, conveyed through topographically ordered output channels; by contrast, striatal input signals originate from a far broader span of cortex, and are far more divergent in their termination...
July 13, 2016: Brain Structure & Function
Ahmad Alhourani, Anna Korzeniewska, Thomas A Wozny, Efstathios Kondylis, Witold J Lipski, Donald Crammond, R Mark Richardson
INTRODUCTION: Beta oscillations play an important role in gating movement. Because pathological oscillatory changes in the beta band represent a hallmark of Parkinson disease (PD), tracking oscillatory changes in this band has been proposed as a marker for closed-loop stimulation. However, the dynamics of casual influences across the motor circuit during movement remain unknown. Using intracranial local field potential (LFP) recordings, we used both standard functional connectivity and event-related causality (ERC) techniques to explore these interactions...
August 2016: Neurosurgery
Yanbing Hou, Jing Yang, Chunyan Luo, Ruwei Ou, Wei Song, Wanglin Liu, Qiyong Gong, Huifang Shang
To map functional connectivity (FC) patterns of early onset Parkinson's disease (EOPD) and late onset PD (LOPD) in drug-naïve early stage. MRI was used to assess atrophy and resting-state FC focusing on striatal subregions of EOPD and LOPD in two subgroups of 18 patients matched for disease duration and severity, relative to age- and sex- matched healthy controls. Compared with controls, both PD subgroups showed FC alterations in cortico-striatal and cerebello-striatal loops but with different patterns in resting state...
October 2016: Journal of Neurology
Alexa R Stephenson, Melissa K Edler, Joseph M Erwin, Bob Jacobs, William D Hopkins, Patrick R Hof, Chet C Sherwood, Mary Ann Raghanti
Cholinergic innervation of the basal ganglia is important in learning and memory. Evidence further indicates that striatal cholinergic neurons integrate cognitive and motivational states with behavior. Given these roles, it is not surprising that deficits in cortical cholinergic innervation have been correlated with loss of cognitive function in Alzheimer's disease and schizophrenia. Such evidence suggests a potentially important role for subcortical cholinergic innervation in the evolution of the human brain...
June 22, 2016: Journal of Comparative Neurology
Christos Ganos
PURPOSE OF REVIEW: To describe recent advances in the pathophysiology of tics and Tourette syndrome, and novel insights on tic control. RECENT FINDINGS: The cortico-basal ganglia-thalamo-cortical loops are implicated in generation of tics. Disruption of GABAergic inhibition lies at the core of tic pathophysiology, but novel animal models also implicate cholinergic and histaminergic neurotransmission. Tourette syndrome patients have altered awareness of volition and enhanced formation of habits...
August 2016: Current Opinion in Neurology
Henry H Yin
The basal ganglia (BG) are the major subcortical nuclei in the brain. Disorders implicating the BG are characterized by diverse symptoms, but it remains unclear what these symptoms have in common or how they can be explained by changes in the BG circuits. This review summarizes recent findings that not only question traditional assumptions about the role of the BG in movement but also elucidate general computations performed by these circuits. To explain these findings, a new conceptual framework is introduced for understanding the role of the BG in behavior...
June 15, 2016: Neuroscientist: a Review Journal Bringing Neurobiology, Neurology and Psychiatry
Chama Belkhiria, Tarak Driss, Christophe Habas, Hamdi Jaafar, Remy Guillevin, Giovanni de Marco
The cerebellum is involved not only in motor coordination, training, and memory, but also in cognition and emotion. Lobule VI in particular belongs to sensorimotor, salience, and executive cerebellar networks. This study aims to determine whether lobule VI would constitute an integrative interface between motor and cognitive/emotional circuits during a motor task with verbal encouragement, likely in conjunction with the basal ganglia (reward and motivational system). We used fMRI to identify specific recruitment of cerebellar and striatal systems during physical performance using two motor tasks with and without encouragement...
June 7, 2016: Cerebellum
Victoria L Corbit, Timothy C Whalen, Kevin T Zitelli, Stephanie Y Crilly, Jonathan E Rubin, Aryn H Gittis
UNLABELLED: In the basal ganglia, focused rhythmicity is an important feature of network activity at certain stages of motor processing. In disease, however, the basal ganglia develop amplified rhythmicity. Here, we demonstrate how the cellular architecture and network dynamics of an inhibitory loop in the basal ganglia yield exaggerated synchrony and locking to β oscillations, specifically in the dopamine-depleted state. A key component of this loop is the pallidostriatal pathway, a well-characterized anatomical projection whose function has long remained obscure...
May 18, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Michiel F Dirkx, Hanneke den Ouden, Esther Aarts, Monique Timmer, Bastiaan R Bloem, Ivan Toni, Rick C Helmich
UNLABELLED: Parkinson's resting tremor has been linked to pathophysiological changes both in the basal ganglia and in a cerebello-thalamo-cortical motor loop, but the role of those circuits in initiating and maintaining tremor remains unclear. Here, we test whether and how the cerebello-thalamo-cortical loop is driven into a tremor-related state by virtue of its connectivity with the basal ganglia. An internal replication design on two independent cohorts of tremor-dominant Parkinson patients sampled brain activity and tremor with concurrent EMG-fMRI...
May 11, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Eric A Yttri, Joshua T Dudman
For goal-directed behaviour it is critical that we can both select the appropriate action and learn to modify the underlying movements (for example, the pitch of a note or velocity of a reach) to improve outcomes. The basal ganglia are a critical nexus where circuits necessary for the production of behaviour, such as the neocortex and thalamus, are integrated with reward signalling to reinforce successful, purposive actions. The dorsal striatum, a major input structure of basal ganglia, is composed of two opponent pathways, direct and indirect, thought to select actions that elicit positive outcomes and suppress actions that do not, respectively...
May 19, 2016: Nature
Julia Sophia Crone, Evan Scott Lutkenhoff, Branden Joseph Bio, Steven Laureys, Martin Max Monti
In recent years, a number of brain regions and connectivity patterns have been proposed to be crucial for loss and recovery of consciousness but have not been compared in detail. In a 3 T resting-state functional magnetic resonance imaging paradigm, we test the plausibility of these different neuronal models derived from theoretical and empirical knowledge. Specifically, we assess the fit of each model to the dynamic change in effective connectivity between specific cortical and subcortical regions at different consecutive levels of propofol-induced sedation by employing spectral dynamic causal modeling...
April 24, 2016: Cerebral Cortex
Sarah Vanhoutte, Marjan Cosyns, Pieter van Mierlo, Katja Batens, Paul Corthals, Miet De Letter, John Van Borsel, Patrick Santens
The present study aimed to evaluate whether increased activity related to speech motor preparation preceding fluently produced words reflects a successful compensation strategy in stuttering. For this purpose, a contingent negative variation (CNV) was evoked during a picture naming task and measured by use of electro-encephalography. A CNV is a slow, negative event-related potential known to reflect motor preparation generated by the basal ganglia-thalamo-cortical (BGTC) - loop. In a previous analysis, the CNV of 25 adults with developmental stuttering (AWS) was significantly increased, especially over the right hemisphere, compared to the CNV of 35 fluent speakers (FS) when both groups were speaking fluently (Vanhoutte et al...
April 19, 2016: Neuropsychologia
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