Short CommunicationContinuous membrane potential fluctuations in motor cortex and striatum neurons during voluntary forelimb movements and pauses

- We analyzed membrane potential dynamics of motor cortex and striatum neurons in vivo.
- They functionally changed membrane potential during forelimb movements and pauses.
- They maintained membrane potential fluctuations during forelimb movements and pauses.
- Their membrane potential fluctuations were strengthened in a quietly resting state.
- Membrane potential, but not its fluctuation, decides movement execution and pausing.

Theoretical simulations suggest that spike rate is regulated by varying both membrane potential and its fluctuation. We investigated whether membrane potential fluctuation functionally changes in motor cortex and striatum neurons during discrete forelimb movements and pauses, or at rest, using whole-cell recording in task-performing rats. Membrane potential fluctuation was diminished by task performance, but maintained overall in the alpha/beta and gamma bands during forelimb movements and pauses. By contrast, membrane potential itself was correlated with spike rate in task-related neurons. Thus, membrane potential, but not its fluctuation, is a critical determinant of execution and pausing of discrete movements.