Research objectives are to understand the mechanisms mediating addictive disorders. Special interest is on how gut, genes, brain, and behavior interact with environment (e.g., developmental drug exposure) to influence addiction. Focus is placed on gut bacteria, genetics, midbrain and limbic brain regions in modulating baseline and drug-induced brain and behavior associations. The goals of the research studies are to further our understanding of the impact of drugs of abuse on the developing and adult brain using animal models, with translational relevance to the human population. The information gathered aims to assist in the promotion of better prevention and intervention strategies for the reduction of addictive disorders in the future.