A twitch of the forelimb is generated in the red nucleus during active
sleep. Sensory feedback (or reafference) from the twitch causes a cascade of
precisely timed neural responses in sensorimotor structures across the neuraxis,
including spinal cord, red nucleus, sensorimotor cortex, and hippocampus.
Through repeated activation of these structures, twitches provide a unique
opportunity for the synchronization of oscillatory activity. See text for
further discussion.