Project Summary Chronic alcohol use has long-lasting detrimental effects on human cognition and behavior that result from changes in brain function. Here we examine changes in corticostriatal circuit function after a 4-week chronic alcohol exposure via alcohol vapor using high-density neural recording (Neuropixels) and optogenetics within rodent models of decision making. In Aim 1 we characterize neural activity changes within the anterior cingulate cortex, orbitofrontal cortex, and dorsomedial striatum as rats exposed to chronic alcohol perform a two-choice probabilistic reversal learning task in which we have previously seen alcohol-induced performance deficits. In Aim 2 we use optogenetic manipulations to probe the role of cingulate cortex-to-dorsomedial striatal and orbitofrontal cortex-to-dorsomedial striatal projections in this behavior in rats exposed to chronic alcohol. In Aim 3, we extend our corticostriatal recording approach to alcohol self-administration to determine if neural activity related to this behavior is altered by prior chronic alcohol exposure via alcohol vapor. Together these studies will provide new information on the impact of chronic alcohol on the activity of large populations of neurons within corticostriatal circuitry that is critical for executive function and cognitive control.