Parietal conditioning enhances motor surround inhibition

Area of Science:

• Neuroscience
• Motor Control
• Human Physiology

Background:

• Motor surround inhibition (mSI) facilitates selective finger movements by activating synergist muscles and inhibiting surround muscles.
• Previous research found no influence of conditioning intracortical and cortico-cortical networks on mSI.
• The role of the inhibitory posterior parietal-motor network in mSI remains uninvestigated despite its importance in fine motor control.

Purpose of the Study:

• To investigate the role of the inhibitory posterior parietal-motor network in motor surround inhibition (mSI).
• To test the hypothesis that conditioning this inhibitory network would enhance mSI.

Main Methods:

• 11 healthy adults participated in the study.
• Motor surround inhibition (mSI) was induced using transcranial magnetic stimulation (TMS) over the motor cortex.
• A conditioning input was applied to an inhibitory posterior parietal cortex spot at 2 or 4 ms intervals.

Main Results:

• Conditioning the posterior parietal cortex significantly increased motor surround inhibition (mSI) by approximately 20%.

Conclusions:

• The inhibitory posterior parietal-motor network plays a role in the generation of motor surround inhibition (mSI).
• Targeting this network may offer new avenues for modulating fine motor control.