Sensorimotor restriction affects complex movement topography and reachable space in the rat motor cortex

Area of Science:

• Neuroscience
• Motor Control
• Sensorimotor Plasticity

Background:

• Intracortical microstimulation (ICMS) reveals functional zones in the motor cortex organizing complex movements.
• Sensorimotor restriction is hypothesized to alter these representations.

Purpose of the Study:

• To investigate how 30-day sensorimotor restriction affects functional zones, complex movements, and reachable space in the rat forelimb M1.
• To assess recovery after 14 days of forelimb use post-restriction.

Main Methods:

• Whole-forelimb casting for 30 days induced sensorimotor restriction.
• Long-duration ICMS was performed before and after cast removal.
• Evoked movements were quantified using a 3D optical system.

Main Results:

• Casting reduced complex movement evocation, functional zone extent, and reachable space.
• Movement kinematics like velocity and trajectory were impaired.
• 14 days of recovery partially restored some parameters but not fully to baseline levels.

Conclusions:

• Sensorimotor restriction induces significant, partially reversible changes in motor cortex organization and function.
• Complex movement aspects may be stored in parallel motor cortex re-entrant systems.