A&N Seminar Series - April 2024 - Joshua Johansen

Host:

Prof. Kei Igarashi (A&N)

Title:

Constructing Emotional Representations in the Brain

Innately aversive experiences profoundly alter brain processing to produce emotional states which coordinate physiological and behavioral responses and instruct memory formation. However, more complex emotions occur through an evaluation of the environment in the context of past experiences and the current physiological condition of the organism. My lab studies the neural circuits and cell coding mechanisms which translate aversive experiences into simple and complex emotional states in the brain to regulate memory formation and guide behavior. I will describe our recent work identifying a brainstem neural circuit which conveys both external-sensory and internal-motor features of innately aversive experiences to create a sensorimotor state in the amygdala for producing aversive memory formation. Contrasting with this bottom-up circuit, we’ve also found that the medial prefrontal cortex encodes more complex emotional states by building an internal associative model to perform emotional inference through top-down projections to the amygdala. These studies support a new hierarchical circuit model of emotion in which sensory, bodily and cognitive factors shape neural processing across distributed neural circuits to adaptively and flexibly control defensive responding and memory formation.