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loops of the basal ganglia

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https://www.readbyqxmd.com/read/29886807/model-and-analysis-for-the-onset-of-parkinsonian-firing-patterns-in-a-simplified-basal-ganglia
#1
Michael Caiola, Mark H Holmes
Parkinson's disease (PD) is a degenerative neurological disease that disrupts the movement cycle in the basal ganglia. As the disease progresses, dopamine depletion leads to changes to how the basal ganglia functions as well as the appearance of abnormal beta oscillations. There is much debate on just exactly how these connection strengths change and just how the oscillations emerge. One leading hypothesis claims that the oscillations develop in the globus pallidus external, subthalamic nucleus, and globus pallidus internal loop...
May 3, 2018: International Journal of Neural Systems
https://www.readbyqxmd.com/read/29861128/conjugate-eye-deviation-caused-by-upper-medial-medullary-infarction-a-case-report
#2
Takashi Ogawa, Yuji Ueno, Hikaru Kamo, Nobukazu Miyamoto, Kazuo Yamashiro, Ryota Tanaka, Yasushi Shimo, Nobutaka Hattori
Conjugate eye deviation (CED) is defined as a sustained shift in horizontal gaze toward 1 side, together with gaze failure to the other side, caused by lesions in the brainstem, basal ganglia, or cortical frontal eye fields. To date, very few reports have described CED in patients with medullary infarction. A 76-year-old woman presented with sudden onset of vertigo and right hemiparesis, accompanied by CED to the right with gaze palsy to the left. Her brain magnetic resonance imaging showed left upper medial medullary infarction involving the left nucleus prepositus hypoglossi (NPH) and adjacent to the left inferior olivary nucleus (ION)...
May 31, 2018: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/29789378/subthalamic-nucleus-neurons-differentially-encode-early-and-late-aspects-of-speech-production
#3
W J Lipski, A Alhourani, T Pirnia, P W Jones, C Dastolfo-Hromack, L B Helou, D J Crammond, S Shaiman, M W Dickey, L L Holt, R S Turner, J A Fiez, R M Richardson
Basal ganglia-thalamocortical loops mediate all motor behavior, yet little detail is known about the role of basal ganglia nuclei in speech production. Using intracranial recording during deep brain stimulation surgery in humans with Parkinson's disease, we tested the hypothesis that the firing rate of subthalamic nucleus neurons is modulated in sync with motor execution aspects of speech. Nearly half of seventy-nine unit recordings exhibited firing rate modulation, during a syllable reading task across twelve subjects (male and female)...
May 22, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29766942/thalamus-and-language-what-do-we-know-from-vascular-and-degenerative-pathologies
#4
Rita Moretti, Paola Caruso, Elena Crisman, Silvia Gazzin
Language is a complex cognitive task that is essential in our daily life. For decades, researchers have tried to understand the different role of cortical and subcortical areas in cerebral language representations and language processing. Language-related cortical zones are richly interconnected with other cortical regions (particularly via myelinated fibre tracts), but they also participate in subcortical feedback loops within the basal ganglia (caudate nucleus and putamen) and thalamus. The most relevant thalamic functions are the control and adaptation of cortico-cortical connectivity and bandwidth for information exchange...
May 2018: Neurology India
https://www.readbyqxmd.com/read/29760177/epigenetic-promoter-dna-methylation-of-mir-124-promotes-hiv-1-tat-mediated-microglial-activation-via-mecp2-stat3-axis
#5
Palsamy Periyasamy, Annadurai Thangaraj, Ming-Lei Guo, Guoku Hu, Shannon Callen, Shilpa Buch
The present study demonstrates HIV-1 Tat-mediated epigenetic downregulation of microglial miR-124 and its association with microglial activation. Exposure of mouse primary microglia isolated from newborn pups of either sex to HIV-1 Tat resulted in decreased expression of primary miR-124-1, primary miR-124-2 as well as the mature miR-124. In parallel, HIV-1 Tat exposure to mouse primary microglial cells resulted in increased expression of DNA methylation enzymes, such as DNMT1, DNMT3A, and DNMT3B that were also accompanied by increased global DNA methylation...
May 14, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29687960/bidirectional-scaling-of-vocal-variability-by-an-avian-cortico-basal-ganglia-circuit
#6
Jonathan B Heston, Joseph Simon, Nancy F Day, Melissa J Coleman, Stephanie A White
Behavioral variability is thought to be critical for trial and error learning, but where such motor exploration is generated in the central nervous system is unclear. The zebra finch songbird species offers a highly appropriate model in which to address this question. The male song is amenable to detailed measurements of variability, while the brain contains an identified cortico-basal ganglia loop that underlies this behavior. We used pharmacogenetic interventions to separately interrogate cortical and basal ganglia nodes of zebra finch song control circuitry...
April 2018: Physiological Reports
https://www.readbyqxmd.com/read/29657115/novelty-sensitive-dopaminergic-neurons-in-the-human-substantia-nigra-predict-success-of-declarative-memory-formation
#7
Jan Kamiński, Adam N Mamelak, Kurtis Birch, Clayton P Mosher, Michele Tagliati, Ueli Rutishauser
The encoding of information into long-term declarative memory is facilitated by dopamine. This process depends on hippocampal novelty signals, but it remains unknown how midbrain dopaminergic neurons are modulated by declarative-memory-based information. We recorded individual substantia nigra (SN) neurons and cortical field potentials in human patients performing a recognition memory task. We found that 25% of SN neurons were modulated by stimulus novelty. Extracellular waveform shape and anatomical location indicated that these memory-selective neurons were putatively dopaminergic...
May 7, 2018: Current Biology: CB
https://www.readbyqxmd.com/read/29614077/a-probabilistic-distributed-recursive-mechanism-for-decision-making-in-the-brain
#8
Javier A Caballero, Mark D Humphries, Kevin N Gurney
Decision formation recruits many brain regions, but the procedure they jointly execute is unknown. Here we characterize its essential composition, using as a framework a novel recursive Bayesian algorithm that makes decisions based on spike-trains with the statistics of those in sensory cortex (MT). Using it to simulate the random-dot-motion task, we demonstrate it quantitatively replicates the choice behaviour of monkeys, whilst predicting losses of otherwise usable information from MT. Its architecture maps to the recurrent cortico-basal-ganglia-thalamo-cortical loops, whose components are all implicated in decision-making...
April 2018: PLoS Computational Biology
https://www.readbyqxmd.com/read/29593596/neural-dynamics-of-autistic-repetitive-behaviors-and-fragile-x-syndrome-basal-ganglia-movement-gating-and-mglur-modulated-adaptively-timed-learning
#9
Stephen Grossberg, Devika Kishnan
This article develops the iSTART neural model that proposes how specific imbalances in cognitive, emotional, timing, and motor processes that involve brain regions like prefrontal cortex, temporal cortex, amygdala, hypothalamus, hippocampus, and cerebellum may interact together to cause behavioral symptoms of autism. These imbalances include underaroused emotional depression in the amygdala/hypothalamus, learning of hyperspecific recognition categories that help to cause narrowly focused attention in temporal and prefrontal cortices, and breakdowns of adaptively timed motivated attention and motor circuits in the hippocampus and cerebellum...
2018: Frontiers in Psychology
https://www.readbyqxmd.com/read/29528521/striatal-cholinergic-receptor-activation-causes-a-rapid-selective-and-state-dependent-rise-in-cortico-striatal-%C3%AE-activity
#10
Benjamin R Pittman-Polletta, Allison Quach, Ali I Mohammed, Michael Romano, Krishnakanth Kondabolu, Nancy J Kopell, Xue Han, Michelle M McCarthy
Cortico-basal ganglia-thalamic (CBT) β oscillations (15-30 Hz) are elevated in Parkinson's disease and correlated with movement disability. To date, no experimental paradigm outside of loss of dopamine has been able to specifically elevate β oscillations in the CBT loop. Here, we show that activation of striatal cholinergic receptors selectively increased β oscillations in mouse striatum and motor cortex. In individuals showing simultaneous β increases in both striatum and M1, β partial directed coherence (PDC) increased from striatum to M1 (but not in the reverse direction)...
March 12, 2018: European Journal of Neuroscience
https://www.readbyqxmd.com/read/29509680/-18-f-fallypride-pet-ct-analysis-of-the-dopamine-d%C3%A2-d%C3%A2-receptor-in-the-hemiparkinsonian-rat-brain-following-intrastriatal-botulinum-neurotoxin-a-injection
#11
Teresa Mann, Jens Kurth, Alexander Hawlitschka, Jan Stenzel, Tobias Lindner, Stefan Polei, Alexander Hohn, Bernd J Krause, Andreas Wree
Intrastriatal injection of botulinum neurotoxin A (BoNT-A) results in improved motor behavior of hemiparkinsonian (hemi-PD) rats, an animal model for Parkinson's disease. The caudate-putamen (CPu), as the main input nucleus of the basal ganglia loop, is fundamentally involved in motor function and directly interacts with the dopaminergic system. To determine receptor-mediated explanations for the BoNT-A effect, we analyzed the dopamine D₂/D₃ receptor (D₂/D₃R) in the CPu of 6-hydroxydopamine (6-OHDA)-induced hemi-PD rats by [18 F]fallypride-PET/CT scans one, three, and six months post-BoNT-A or -sham-BoNT-A injection...
March 6, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29503326/tremor-syndromes-a-review
#12
REVIEW
Nitish Kamble, Pramod Kumar Pal
Among the involuntary movement disorders, tremor is a common phenomenology seen in clinical practice. The important factors that need to be determined while assessing a patient with tremor include the phenomenology of tremor, presence or absence of other neurologic signs, and the effect of medications or alcohol. Tremor can broadly be classified based on the circumstances under which it occurs, i.e., rest or action. The basal ganglia-cerebello-thalamic and dentate-olivary circuits are involved in the generation of tremor...
March 2018: Neurology India
https://www.readbyqxmd.com/read/29467627/basal-ganglia-neuromodulation-over-multiple-temporal-and-structural-scales-simulations-of-direct-pathway-msns-investigate-the-fast-onset-of-dopaminergic-effects-and-predict-the-role-of-kv4-2
#13
Robert Lindroos, Matthijs C Dorst, Kai Du, Marko Filipović, Daniel Keller, Maya Ketzef, Alexander K Kozlov, Arvind Kumar, Mikael Lindahl, Anu G Nair, Juan Pérez-Fernández, Sten Grillner, Gilad Silberberg, Jeanette Hellgren Kotaleski
The basal ganglia are involved in the motivational and habitual control of motor and cognitive behaviors. Striatum, the largest basal ganglia input stage, integrates cortical and thalamic inputs in functionally segregated cortico-basal ganglia-thalamic loops, and in addition the basal ganglia output nuclei control targets in the brainstem. Striatal function depends on the balance between the direct pathway medium spiny neurons (D1-MSNs) that express D1 dopamine receptors and the indirect pathway MSNs that express D2 dopamine receptors...
2018: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/29427344/directional-communication-during-movement-execution-interferes-with-tremor-in-parkinson-s-disease
#14
Georgios Naros, Florian Grimm, Daniel Weiss, Alireza Gharabaghi
BACKGROUND: Both the cerebello-thalamo-cortical circuit and the basal ganglia/cortical motor loop have been postulated to be generators of tremor in PD. The recent suggestion that the basal ganglia trigger tremor episodes and the cerebello-thalamo-cortical circuitry modulates tremor amplitude combines both competing hypotheses. However, the role of the STN in tremor generation and the impact of proprioceptive feedback on tremor suppression during voluntary movements have not been considered in this model yet...
February 2018: Movement Disorders: Official Journal of the Movement Disorder Society
https://www.readbyqxmd.com/read/29396173/the-neuropsychology-of-basal-ganglia
#15
REVIEW
Daria Riva, Matilde Taddei, Sara Bulgheroni
Basal ganglia are subcortical structures specialized at very early age, functionally different according to the right or left side. They are part of complex distributed network composed by parallel segregated loops where specific information are processed and open loops where different information are integrated. These loops are connected to specialized cortical areas thus entering into distributed processing of higher order cognitive functions and behaviours. Lesion or malfunction of basal ganglia nuclei cause deficits in different neuropsychological functions and neurobehavioural diseases, such Autism Spectrum Disorder, Attention Deficit/Hyperactivity Disorder, Tourette syndrome, etc...
March 2018: European Journal of Paediatric Neurology: EJPN
https://www.readbyqxmd.com/read/29381817/oscillatory-activity-in-the-cortico-basal-ganglia-thalamic-neural-circuits-in-parkinson-s-disease
#16
REVIEW
Arun Singh
Dopamine is an important neurotransmitter that maintains the balance within the basal ganglia between the direct pathway, which promotes movement, and the indirect pathway, which inhibits movement. Degeneration of dopaminergic neurons in the substantia nigra increases the influence of the indirect pathway, resulting in motor dysfunction in Parkinson's disease (PD). The direct and indirect pathways are composed of basal ganglia and thalamic nuclei, which are interconnected via independent parallel loop circuits with cortical areas and often referred to as cortico-basal ganglia-thalamic (CBT) neural circuits...
January 30, 2018: European Journal of Neuroscience
https://www.readbyqxmd.com/read/29298733/progressive-striatonigral-degeneration-in-a-transgenic-mouse-model-of-multiple-system-atrophy-translational-implications-for-interventional-therapies
#17
Violetta Refolo, Francesco Bez, Alexia Polissidis, Daniela Kuzdas-Wood, Edith Sturm, Martina Kamaratou, Werner Poewe, Leonidas Stefanis, M Angela Cenci, Marina Romero-Ramos, Gregor K Wenning, Nadia Stefanova
Multiple system atrophy (MSA) is a rapidly progressive neurodegenerative disorder characterized by widespread oligodendroglial cytoplasmic inclusions of filamentous α-synuclein, and neuronal loss in autonomic centres, basal ganglia and cerebellar circuits. It has been suggested that primary oligodendroglial α-synucleinopathy may represent a trigger in the pathogenesis of MSA, but the mechanisms underlying selective vulnerability and disease progression are unclear. The post-mortem analysis of MSA brains provides a static final picture of the disease neuropathology, but gives no clear indication on the sequence of pathogenic events in MSA...
January 3, 2018: Acta Neuropathologica Communications
https://www.readbyqxmd.com/read/29295486/adaptive-deep-brain-stimulation-adbs-for-tourette-syndrome
#18
Sara Marceglia, Manuela Rosa, Domenico Servello, Mauro Porta, Sergio Barbieri, Elena Moro, Alberto Priori
Deep brain stimulation (DBS) has emerged as a novel therapy for the treatment of several movement and neuropsychiatric disorders, and may also be suitable for the treatment of Tourette syndrome (TS). The main DBS targets used to date in patients with TS are located within the basal ganglia-thalamo-cortical circuit involved in the pathophysiology of this syndrome. They include the ventralis oralis/centromedian-parafascicular (Vo/CM-Pf) nucleus of the thalamus and the nucleus accumbens. Current DBS treatments deliver continuous electrical stimulation and are not designed to adapt to the patient's symptoms, thereby contributing to unwanted side effects...
December 23, 2017: Brain Sciences
https://www.readbyqxmd.com/read/29291546/nonlinear-predictive-control-for-adaptive-adjustments-of-deep-brain-stimulation-parameters-in-basal-ganglia-thalamic-network
#19
Fei Su, Jiang Wang, Shuangxia Niu, Huiyan Li, Bin Deng, Chen Liu, Xile Wei
The efficacy of deep brain stimulation (DBS) for Parkinson's disease (PD) depends in part on the post-operative programming of stimulation parameters. Closed-loop stimulation is one method to realize the frequent adjustment of stimulation parameters. This paper introduced the nonlinear predictive control method into the online adjustment of DBS amplitude and frequency. This approach was tested in a computational model of basal ganglia-thalamic network. The autoregressive Volterra model was used to identify the process model based on physiological data...
February 2018: Neural Networks: the Official Journal of the International Neural Network Society
https://www.readbyqxmd.com/read/29236966/neuronal-inhibition-and-synaptic-plasticity-of-basal-ganglia-neurons-in-parkinson-s-disease
#20
Luka Milosevic, Suneil K Kalia, Mojgan Hodaie, Andres M Lozano, Alfonso Fasano, Milos R Popovic, William D Hutchison
Deep brain stimulation of the subthalamic nucleus is an effective treatment for Parkinson's disease symptoms. The therapeutic benefits of deep brain stimulation are frequency-dependent, but the underlying physiological mechanisms remain unclear. To advance deep brain stimulation therapy an understanding of fundamental mechanisms is critical. The objectives of this study were to (i) compare the frequency-dependent effects on cell firing in subthalamic nucleus and substantia nigra pars reticulata; (ii) quantify frequency-dependent effects on short-term plasticity in substantia nigra pars reticulata; and (iii) investigate effects of continuous long-train high frequency stimulation (comparable to conventional deep brain stimulation) on synaptic plasticity...
December 11, 2017: Brain: a Journal of Neurology
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