Mike JF Robinson, Ph.D. - US grants

Project Summary/Abstract Wesleyan University Poor decision-making can lead to drug use and substance use disorder in both males and females, and is predictive of relapse vulnerability. Decision-making is a complex behavior that integrates moderating cortical influences with subcortical urges. When the decision process becomes unbalanced in favor of subcortical urges, it may lead to compulsive choice, the pursuit of risky options, and the development of drug addiction. Dysfunction of the prefrontal cortex is believed to bias this process in favor of those subcortical urges. In particular, recent findings suggest that cortical activity in areas such as the anterior insula (AIC) and orbitofrontal (OFC) cortex may influence decisions, possibly by moderating these urges. However, recent pharmacological and lesion studies of the OFC and AIC conflate decision- making processes and their outcomes, and fail to capture the role of these areas `in the moment'. In addition, there are large individual differences in risky decision-making including sex differences in the activity of the AIC and OFC. The long-term goal of this project is to understand how, and the timing with which, the AIC and OFC influence risky decision-making. Important to this project, our preliminary data using optogenetic techniques has revealed a more complex role for the AIC than previously appreciated, showing that brief inhibition prior to making a choice increases risk-preference, whereas inhibition following risky wins, but not risky losses, dramatically increases risk-aversion. This suggests that the AIC tracks only positive risky outcomes, and uses this information during the deliberation process to promote future safe choices. In contrast, our preliminary work also shows that brief inhibition of the OFC prior to making a choice reduces risk preference. This suggests that the OFC normally increases risky choice and plays an opposing role to that of the AIC. Building on these preliminary findings, the objective of this proposal is to 1) test the hypothesis that the role of the AIC is to attenuate risky choices and that it does so by tracking risky wins, 2) test the hypothesis that the OFC has the opposite effect on risky decision-making, by increasing risky choices, particularly when a choice is presented, and finally 3) that females are more risk-averse and will therefore be less sensitive to optogenetic manipulations that increase risk-seeking. This will be achieved using advanced behavioral task designs combined with the temporal specificity of optogenetics to specifically inhibit the OFC or AIC either immediately prior to choice or following particular risky reward outcomes. This research will advance our understanding of the role and precise timing with which cortical structures influence risky decision-making and how these functions are influenced by individual risk preferences and sex differences. This will provide foundational knowledge necessary to develop intervention strategies aimed at reducing risk-taking and drug use.