Rapid changes in throughput from single motor cortex neurons to muscle activity.

Area of Science:

• Neuroscience
• Motor Control
• Neuroplasticity

Background:

• Motor cortex exhibits significant reorganization through excitability modulation.
• Previous research focused on cortical changes, leaving extracortical reorganization less understood.

Purpose of the Study:

• To investigate if motor cortex reorganization extends to the throughput from single motor cortex neurons to muscle activity.
• To explore changes in functional connectivity beyond the cortex during a task incentivizing enhanced motor output.

Main Methods:

• Recorded single motor cortex neuron activity and corresponding muscle activity.
• Utilized a behavioral paradigm designed to encourage enhanced functional connectivity.
• Analyzed short-latency throughput from neurons to muscles across different behavioral epochs.

Main Results:

• Observed short-latency throughput from recorded neurons to muscle activity that varied between behavioral epochs.
• These changes in throughput were not consistently explained by increased neuron firing rate, ongoing muscle activity, or neuronal synchronization.
• Demonstrated that functional connectivity between single motor cortex neurons and alpha-motoneuron pools can change rapidly.

Conclusions:

• Motor cortex output reorganization involves rapid alterations in functional connectivity at the single-neuron to muscle level.
• These findings suggest significant neuroplasticity occurs beyond the motor cortex, impacting motor control.
• The study highlights dynamic changes in the motor system's throughput, offering new insights into motor learning and adaptation.