This five-year, $573,638 project grant from the National Institute on Drug Abuse, part of the Department of Health and Human Services, supports research into the neural mechanisms of individual differences in cocaine avoidance. Funded under the Drug Abuse and Addiction Research Programs (CFDA 93.279), the grant to the Medical University of South Carolina will examine cellular mechanisms by which serotonin and glutamate receptors in the rostromedial tegmental nucleus drive aversive conditioning responses to cocaine. Understanding these aversive effects is important as they strongly influence drug-seeking behavior and exhibit large variability between individuals, contributing to differences in addiction risk. The research aims to identify novel therapeutic targets for regulating drug-seeking and treating addiction by developing new knowledge on why aversive responses occur more strongly in some people than others.