scholarly journals Activity of the same motor cortex neurons during repeated experience with perturbed movement dynamics

2012 ◽  
Vol 107 (11) ◽  
pp. 3144-3154 ◽  
Author(s):  
Andrew G. Richardson ◽  
Tommaso Borghi ◽  
Emilio Bizzi
Keyword(s):  
Motor Cortex ◽  
Force Field ◽  
Primary Motor Cortex ◽  
Neuronal Population ◽  
Directional Tuning ◽  
Tuning Curves ◽  
Performance Improvements ◽  
Memory Traces ◽  
Movement Dynamics

Neurons in the primary motor cortex (M1) have been shown to have persistent, memory-like activity following adaptation to altered movement dynamics. However, the techniques used to study these memory traces limited recordings to only single sessions lasting no more than a few hours. Here, chronically implanted microelectrode arrays were used to study the long-term neuronal responses to repeated experience with perturbing, velocity-dependent force fields. Force-field–related neuronal activity within each session was similar to that found previously. That is, the directional tuning curves of the M1 neurons shifted in a manner appropriate to compensate for the forces. Next, the across-session behavior was examined. Long-term learning was evident in the performance improvements across multiple force-field sessions. Correlated with this change, the neuronal population had smaller within-session spike rate changes as experience with the force field increased. The smaller within-session changes were a result of persistent across-session shifts in directional tuning. The results extend the observation of memory traces of newly learned dynamics and provide further evidence for the role of M1 in early motor memory formation.

scholarly journals Brain stimulation for arm recovery after stroke (B-STARS): protocol for a randomised controlled trial in subacute stroke patients

BMJ Open ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. e016566
Author(s):  
Eline C C van Lieshout ◽  
Johanna M A Visser-Meily ◽  
Sebastiaan F W Neggers ◽  
H Bart van der Worp ◽  
Rick M Dijkhuizen
Keyword(s):  
Motor Cortex ◽  
Upper Limb ◽  
Brain Stimulation ◽  
Primary Outcome ◽  
Primary Motor Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Stroke Patients ◽  
Post Stroke ◽  
Subacute Stroke

IntroductionMany patients with stroke have moderate to severe long-term sensorimotor impairments, often including inability to execute movements of the affected arm or hand. Limited recovery from stroke may be partly caused by imbalanced interaction between the cerebral hemispheres, with reduced excitability of the ipsilesional motor cortex while excitability of the contralesional motor cortex is increased. Non-invasive brain stimulation with inhibitory repetitive transcranial magnetic stimulation (rTMS) of the contralesional hemisphere may aid in relieving a post-stroke interhemispheric excitability imbalance, which could improve functional recovery. There are encouraging effects of theta burst stimulation (TBS), a form of TMS, in patients with chronic stroke, but evidence on efficacy and long-term effects on arm function of contralesional TBS in patients with subacute hemiparetic stroke is lacking.Methods and analysisIn a randomised clinical trial, we will assign 60 patients with a first-ever ischaemic stroke in the previous 7–14 days and a persistent paresis of one arm to 10 sessions of real stimulation with TBS of the contralesional primary motor cortex or to sham stimulation over a period of 2 weeks. Both types of stimulation will be followed by upper limb training. A subset of patients will undergo five MRI sessions to assess post-stroke brain reorganisation. The primary outcome measure will be the upper limb function score, assessed from grasp, grip, pinch and gross movements in the action research arm test, measured at 3 months after stroke. Patients will be blinded to treatment allocation. The primary outcome at 3 months will also be assessed in a blinded fashion.Ethics and disseminationThe study has been approved by the Medical Research Ethics Committee of the University Medical Center Utrecht, The Netherlands. The results will be disseminated through (open access) peer-reviewed publications, networks of scientists, professionals and the public, and presented at conferences.Trial registration numberNTR6133

Long-term effect of safinamide on primary motor cortex excitability and plasticity in Parkinson's disease: A TMS study

2021 ◽  
Vol 429 ◽  
pp. 119453
Author(s):  
Valentina D'Onofrio ◽  
Andrea Guerra ◽  
Francesco Asci ◽  
Giovanni Fabbrini ◽  
Alfredo Berardelli ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Term Effect ◽  
Long Term Effect ◽  
Motor Cortex Excitability

Systematic Changes in Directional Tuning of Motor Cortex Cell Activity With Hand Location in the Workspace During Generation of Static Isometric Forces in Constant Spatial Directions

1997 ◽  
Vol 78 (2) ◽  
pp. 1170-1174 ◽  
Author(s):  
Lauren E. Sergio ◽  
John F. Kalaska
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Discharge Rate ◽  
Cell Activity ◽  
Force Production ◽  
Static Force ◽  
Force Output ◽  
Directional Tuning ◽  
Cortex Cell ◽  
Isometric Forces

Sergio, Lauren E. and John F. Kalaska. Systematic changes in directional tuning of motor cortex cell activity with hand location in the workspace during generation of static isometric forces in constant spatial directions. J. Neurophysiol. 78: 1170–1174, 1997. We examined the activity of 46 proximal-arm-related cells in the primary motor cortex (MI) during a task in which a monkey uses the arm to exert isometric forces at the hand in constant spatial directions while the hand is in one of nine different spatial locations on a plane. The discharge rate of all 46 cells was significantly affected by both hand location and by the direction of static force during the final static-force phase of the task. In addition, all cells showed a significant interaction between force direction and hand location. That is, there was a significant modulation in the relationship between cell activity and the direction of exerted force as a function of hand location. For many cells, this modulation was expressed in part as a systematic arclike shift in the cell's directional tuning at the different hand locations, even though the direction of static force output at the hand remained constant. These effects of hand location in the workspace indicate that the discharge of single MI cells does not covary exclusively with the level and direction of force output at the hand. Sixteen proximal-arm-related muscles showed similar effects in the task, reflecting their dependence on various mechanical factors that varied with hand location. The parallel changes found for both MI cell activity and muscle activity for static force production at different hand locations are further evidence that MI contributes to the transformation between extrinsic and intrinsic representations of limb movement.

Short-term and long-term plasticity interaction in human primary motor cortex

2011 ◽  
Vol 33 (10) ◽  
pp. 1908-1915 ◽  
Author(s):  
Ennio Iezzi ◽  
Antonio Suppa ◽  
Antonella Conte ◽  
Pietro Li Voti ◽  
Matteo Bologna ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Short Term

scholarly journals Heat-Evoked Experimental Pain Induces Long-Term Potentiation-Like Plasticity in Human Primary Motor Cortex

2012 ◽  
Vol 23 (8) ◽  
pp. 1942-1951 ◽  
Author(s):  
A. Suppa ◽  
A. Biasiotta ◽  
D. Belvisi ◽  
L. Marsili ◽  
S. La Cesa ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Experimental Pain ◽  
Long Term Potentiation ◽  
Term Potentiation

scholarly journals Plasticity of the Cortical Motor System

2008 ◽  
Vol 20 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Bogdan Sadowski
Keyword(s):  
Motor Cortex ◽  
Motor System ◽  
Primary Motor Cortex ◽  
Pyramidal Neurons ◽  
Pyramidal Cells ◽  
Long Term Potentiation ◽  
Skill Learning ◽  
Dynamic Features ◽  
Cortical Motor

Plasticity of the Cortical Motor SystemThe involvement of brain plastic mechanisms in the control of motor functions under normal and pathological conditions is described. These mechanisms are based on a similar principle as the neuronal models of neuronal plasticity - long-term potentiation (LTP), and long-term depression (LTD). In the motor cortex, LTP-like phenomena play a role in strengthening synaptic connections between pyramidal neurons. LTD is important for the elimination of unnecessary inputs to the cortex. The dynamic features of the primary motor cortex activity depend on particular neuronal interconnectivity within this area. The pyramidal cells send horizontal collaterals to adjacent subregions of the primary motor cortex, and so can either excite or inhibit remote pyramidal cells. These connections can expand or shrink depending on actual physiological demands, and play a role in skill learning.

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