Cerebellar Transcranial Direct Current Stimulation Modulates Anticipatory Postural Adjustments in Healthy Adults

Area of Science:

• Neuroscience
• Motor Control
• Human Physiology

Background:

• The central nervous system anticipates body changes during arm movements.
• The cerebellar network coordinating anticipatory postural adjustments (APAs) is not well understood.
• Cerebellar transcranial direct current stimulation (tDCS) can modulate neural activity.

Purpose of the Study:

• To investigate the role of the cerebellum in coordinating APAs during bilateral rapid shoulder flexion.
• To determine if cerebellar tDCS affects APA onset, postural stability, or arm movement kinematics.
• To explore cerebellar involvement in APAs in healthy adults.

Main Methods:

• Used surface electromyography (sEMG) to measure muscle activity during a bilateral rapid shoulder flexion task.
• Applied cerebellar tDCS to different cerebellar regions with varying polarities.
• Analyzed the onset of APAs, postural stability, and arm raising kinematics.

Main Results:

• tDCS over the cerebellar vermis altered the onset of APAs.
• Postural stability and arm raising kinematics remained unaffected by cerebellar tDCS.
• This is the first human cerebellar-tDCS (c-tDCS) study to differentiate cerebellar roles in core muscle APAs during this task.

Conclusions:

• The cerebellar vermis plays a specific role in regulating the timing of APAs during arm movements.
• Modulation of erector spinae APAs by vermal tDCS may involve altered cerebellar brain inhibition (CBI).
• Highlights the importance of vermal-cerebral connections in APA regulation.