Faculty Presentation - Dr. Melissa Warden
Title: Intense threat switches dorsal raphe serotonin neurons to a paradoxical operational mode
Survival depends on the selection of behaviors adaptive for the current environment. For example, a mouse should run from a rapidly looming hawk but should freeze if the hawk is coasting across the sky. Although serotonin has been implicated in adaptive behavior, environmental regulation of its functional role remains poorly understood. Using optical methods in freely moving mice, we found that stimulation of dorsal raphe serotonin neurons suppressed movement in low- and moderate-threat environments but induced escape behavior in high-threat environments, and that movement-related serotonin neural dynamics inverted in high-threat environments. Additionally, we found that stimulation of dorsal raphe GABA neurons selectively promoted movement in negative but not positive environments. Thus, dorsal raphe circuits switch between distinct operational modes to promote environment-specific adaptive behaviors.