Disorders involving social behaviors such as autism spectrum disorder are increasingly prevalent, yet the pathophysiological bases for these conditions elude researchers and current treatments are woefully inadequate. The insular cortex is highly implicated in both normal and pathological social affective processes such as emotion recognition and empathy. The insular cortex receives a major input from the amygdala and so it is likely a site of integration for social and emotional information leading to modulation of social approach and avoidance behaviors via insular projections to the nucleus accumbens. Using a simple rodent social behavioral test in which rats display approach behaviors to conspecifics in distress, we hypothesize that an amygdala to insula to accumbens circuit mediates social responses to stressed individuals. We will use tract specific descriptive and mechanistic methods to establish the necessity and sufficiency of insula-projecting amygdala neurons and accumbens-projecting insula neurons in social decision making. Using activity dependent genetic labeling of insular cortex neurons we will address whether insula-dependent approach and avoidant behaviors are mediated by the same or distinct subsets of insula neurons. This work will inform the development of new treatments of social disorders and provide mechanistic tests of major theoretical models of the social brain.
The insular cortex is implicated in the pathophysiology of psychosocial disorders including autism, yet mechanistic research into basic contributions of the insula social cognition is lacking. The insular cortex is a nexus of sensory and emotional information and relay to social reward circuits and so it is thought to contribute to emotion recognition and empathy. We propose a multidisciplinary, intersectional study to define how emotion and social approach are integrated within the insular cortex of rat.