Jimmy Dooley, PhD and Mark Blumberg, PhD
About this talk
Twitches occur in skeletal muscles across the entire body from infancy through adulthood and are exclusively produced during REM sleep. In rats, Dooley and Blumberg have shown that sensory feedback from these twitches drives neural activity in primary motor cortex (M1) from postnatal day (P) 4 through at least P12. Although twitches are present at later ages, it is not known whether they continue to drive cortical activity. Here, they recorded neural activity in both the forelimb representation of M1 and the motor thalamus in preweanling rats. During that time, REM sleep decreased but neurons in both M1 and motor thalamus continued to show twitch-related activity rats at P12 and P16. Motor thalamus activity lagged the twitches, while at P20, activity in the motor thalamus tracked the twitches with high fidelity. This precise correspondence between twitch-related activity and movements in motor thalamus is an internal representation of a subcortical motor command.
Jimmy Dooley, PhD is a Postdoc in the laboratory of Dr. Mark Blumberg at the University of Iowa, where his research focuses on self-generated movements that drive state-dependent activity in the developing sensorimotor system. Mark Blumberg, PhD is the Department Chair at the University of Iowa. His research focuses on sleep and its development, neural control, and functional significance. His lab uses behavioral, neurophysiological, neuroanatomical, and genetic approaches to help us understand why we sleep so much when we are young and what can go wrong when we don’t.