scholarly journals Deficit in motor skill learning-dependent synaptic plasticity at motor cortex to Dorso Lateral Striatum synapses in a mouse model of Huntington's disease

2019 ◽  
Author(s):  
Christelle Glangetas ◽  
Pedro Espinosa ◽  
Camilla Bellone
Keyword(s):  
Synaptic Plasticity ◽  
Motor Cortex ◽  
Mouse Model ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Motor Skill ◽  
Dynamic Change ◽  
Skill Learning ◽  
Lateral Part ◽  
Motor Skill Learning

Huntington's disease (HD) is a neurodegenerative disease notably characterized by progressive motor symptoms. Although the loss of Medium Spiny Neurons (MSNs) in the striatum has been associated with motor deficits, premanifest patients already present cognitive deficiencies and show early signs of motor disabilities. Here in a YAC128 HD mouse model, we identified impairment in motor skill learning at the age of 11 to 14 weeks. Using optogenetic stimulation, we found that excitatory synaptic transmission from motor cortex to MSNs located in the Dorso Lateral part of the Striatum (DLS) is altered. Using single pellet reaching task, we observed that while motor skill learning is accompanied by a dynamic change in AMPA/NMDA ratio in wild type mice, this form of synaptic plasticity does not occur in YAC128 mice. This study not only proposes new meaningful insight the synaptopathic mechanisms of HD, but also highlights that deficit in motor skill learning dependent synaptic plasticity at motor cortex to DLS synapses represents an early biomarker for Huntington's disease.

scholarly journals Altered Structural and Functional Synaptic Plasticity with Motor Skill Learning in a Mouse Model of Fragile X Syndrome

2013 ◽  
Vol 33 (50) ◽  
pp. 19715-19723 ◽  
Author(s):  
R. Padmashri ◽  
B. C. Reiner ◽  
A. Suresh ◽  
E. Spartz ◽  
A. Dunaevsky
Keyword(s):  
Synaptic Plasticity ◽  
Mouse Model ◽  
Fragile X Syndrome ◽  
Motor Skill ◽  
Fragile X ◽  
Skill Learning ◽  
Motor Skill Learning

scholarly journals Motor Cortex Plasticity Response to Acute Cardiorespiratory Exercise and Intermittent Theta-Burst Stimulation is Attenuated in Premanifest and Early Huntington’s Disease

2021 ◽  
Author(s):  
Sophie C. Andrews ◽  
Dylan Curtin ◽  
James P. Coxon ◽  
Julie C. Stout
Keyword(s):  
Synaptic Plasticity ◽  
Motor Cortex ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
High Intensity ◽  
High Intensity Exercise ◽  
Moderate Intensity ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Theta Burst

Abstract Huntington’s disease (HD) mouse models suggest that cardiovascular exercise may enhance neuroplasticity and delay disease signs, however, the effects of exercise on neuroplasticity in people with HD are unknown. Using a repeated-measures experimental design, we compared the effects of a single bout of high-intensity exercise, moderate-intensity exercise, or rest, on motor cortex synaptic plasticity in 14 HD CAG-expanded participants (9 premanifest & 5 early manifest) and 20 CAG-healthy control participants, using transcranial magnetic stimulation. Measures of cortico-motor excitability, short-interval intracortical inhibition and intracortical facilitation were obtained before and after a 20-minute bout of either high-intensity interval exercise, moderate-intensity continuous exercise, or rest, and again after intermittent theta burst stimulation (iTBS). HD participants showed less inhibition at baseline compared to controls. Whereas the control group showed increased excitability and facilitation following high-intensity exercise and iTBS, the HD group showed no differences in neuroplasticity responses following either exercise intensity or rest, with follow-up Bayesian analyses providing consistent evidence that these effects were absent in the HD group. These findings indicate that exercise-induced synaptic plasticity mechanisms in response to acute exercise may be attenuated in HD, and demonstrate the need for future research to further investigate exercise and plasticity mechanisms in people with HD.

scholarly journals Somatosensory changes associated with motor skill learning

2020 ◽  
Vol 123 (3) ◽  
pp. 1052-1062 ◽  
Author(s):  
Jasmine L. Mirdamadi ◽  
Hannah J. Block
Keyword(s):  
Motor Cortex ◽  
Motor Skill ◽  
Motor Adaptation ◽  
Short Latency ◽  
Skill Learning ◽  
Motor Skill Learning ◽  
Short Latency Afferent Inhibition ◽  
Afferent Inhibition ◽  
Speed Accuracy ◽  
Somatosensory Function

Trial-and-error motor adaptation has been linked to somatosensory plasticity and shifts in proprioception (limb position sense). The role of sensory processing in motor skill learning is less understood. Unlike adaptation, skill learning involves the acquisition of new movement patterns in the absence of perturbation, with performance limited by the speed-accuracy trade-off. We investigated somatosensory changes during motor skill learning at the behavioral and neurophysiological levels. Twenty-eight healthy young adults practiced a maze-tracing task, guiding a robotic manipulandum through an irregular two-dimensional track featuring several abrupt turns. Practice occurred on days 1 and 2. Skill was assessed before practice on day 1 and again on day 3, with learning indicated by a shift in the speed-accuracy function between these assessments. Proprioceptive function was quantified with a passive two-alternative forced-choice task. In a subset of 15 participants, we measured short-latency afferent inhibition (SAI) to index somatosensory projections to motor cortex. We found that motor practice enhanced the speed-accuracy skill function ( F4,108 = 32.15, P < 0.001) and was associated with improved proprioceptive sensitivity at retention ( t22 = 24.75, P = 0.0031). Furthermore, SAI increased after training ( F1,14 = 5.41, P = 0.036). Interestingly, individuals with larger increases in SAI, reflecting enhanced somatosensory afference to motor cortex, demonstrated larger improvements in motor skill learning. These findings suggest that SAI may be an important functional mechanism for some aspect of motor skill learning. Further research is needed to test what parameters (task complexity, practice time, etc.) are specifically linked to somatosensory function. NEW & NOTEWORTHY Somatosensory processing has been implicated in motor adaptation, where performance recovers from a perturbation such as a force field. We investigated somatosensory function during motor skill learning, where a new motor pattern is acquired in the absence of perturbation. After skill practice, we found changes in proprioception and short-latency afferent inhibition (SAI), signifying somatosensory change at both the behavioral and neurophysiological levels. SAI may be an important functional mechanism by which individuals learn motor skills.

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