Guest Presenter: Beverly Setzer (Graduate student at Dr. Laura Lewis’s lab, Boston University)

Talk Title: Fast fMRI delineates an activation sequence across thalamic nuclei during awakening

Abstract: The moment of awakening from sleep reflects a profound transformation in neural activity and behavior. The thalamus is a key controller of arousal state, but whether its diverse nuclei exhibit coordinated or distinct activity at transitions in behavioral arousal state is not known. Using simultaneous EEG-fMRI and fast fMRI at ultra-high field (7 Tesla), we measured sub-second activity across thalamocortical networks and within nine thalamic nuclei to delineate these dynamics during spontaneous transitions in behavioral arousal state. We discovered a stereotyped sequence of activity across thalamic nuclei that preceded behavioral arousal after a period of inactivity, followed by widespread cortical deactivation. These results provide an outline of the complex interactions across thalamocortical circuits that orchestrate arousal state transitions, and additionally, that fast fMRI can resolve sub-second subcortical dynamics in the human brain.