Host: Darcy Kelley
Title: Extended amygdala circuits involved in fear learning, expression and extinction
Abstract: Pavlovian fear conditioning is a useful model for examining the neurobiological substrates of associative learning and memory formation. Indeed, many of the mechanisms underlying the acquisition and extinction of classically conditioned fear responses have been characterized. We are interested in studying activity at the cellular level as well as interactions among different neural structures to gain a clearer insight into behavioral processes.
One group of experiments focuses on the cellular and molecular changes that occur in the basolateral nucleus of the amygdala (BLA) during fear learning, expression and extinction. As one example, we find that the neuropeptide corticotropin-releasing factor, whose receptors are localized to specific subtypes of inhibitory interneurons in the BLA, impairs fear extinction memories. A second group of experiments examines the interactions between different brain regions which contribute to fear-like and anxiety-like behavior. We find that the bed nucleus of the stria terminalis (BNST), a part of the extended amygdala, can be recruited into the fear circuitry under certain pharmacological and behavioral conditions. Ongoing experiments are determining the cellular characteristics of the BNST-amygdala pathway.