CSB Seminar: Jimmy Dooley, PhD – Purdue University, Department of Biological Sciences

CSB Departmental Seminar

Friday, October 31st @ 11:00 am

SPEAKER: Jimmy Dooley, PhD – Purdue University, Department of Biological Sciences

TITLE: Sleep like a baby: How REM sleep helps the brain learn to move.

ABSTRACT: 

Despite its name, the motor functions of motor cortex (M1) emerge relatively late—as late as 4-6 months postnatal in humans and around postnatal day (P) 25 in rats. By contrast, brainstem structures—such as the red nucleus (RN) of the midbrain—produce movements during sleep and wake throughout infancy and these movements drive ongoing M1 activity. But M1 eventually assumes motor control, the development of which depends on both brainstem-generated movements and M1 activity. As M1 develops, it engages in activity-dependent competition with RN for control of movement. Anatomical studies and experiments in anesthetized animals have suggested a mechanism for this competition: Cortical projections to RN mostly synapse onto parvalbumin-positive (PV+) inhibitory neurons. Thus, M1 inhibits RN, but prior to my lab’s recent work, the function of this inhibition has not been established in unanesthetized animals. In this talk, I will present evidence that M1 inhibits RN in a strikingly state-dependent manner—during REM sleep, but not during wake. This inhibition appears to rely on PV+ RN neurons, which are especially active in REM sleep. These findings overturn long-standing assumptions drawn from wake-based studies and highlight sleep as a critical window for the developing cortex to reshape motor control.

HOST: Jimmy Fraigne

LOCATION: Cell and Systems Biology, 25 Harbord Street, Suite 432

LIVESTREAM LINK: https://csb.utoronto.ca/live-stream/