PROJECT SUMMARY/ABSTRACT Addiction is an enormous economic, personal, and social burden, costing over $600 billion per year in the U.S. Understanding vulnerability to addiction, and developing effective therapies, requires identifying the genes and pathways that mediate the addiction process. Our long-term goal is to develop novel genetic models for addiction-relevant phenotypes, and use these models to characterize the genetic mechanisms of addiction. We propose to leverage the Jackson Laboratory Knockout Mouse Project 2 (JAX KOMP2) pipeline to prioritize addiction gene candidates, and then characterize the effects of candidate gene knockouts on addiction-related behaviors and on addiction-relevant tissues. The JAX KOMP2 Phenotyping Center performs high-throughput phenotyping of knockout mice across organ systems using an efficient, broad-based testing pipeline including behavioral assays for emotionality and sleep, both predictive of addiction phenotypes. Here we propose to exploit this rich KOMP2 dataset to select a subset of lines with emotionality and neuronal phenotypes (e.g. deviant open field, light dark, hole board, tail suspension, prepulse inhibition, rotarod, electroconvulsive seizure threshold, or sleep phenotypes) and lacking metabolism and physiology phenotypes. Our preliminary data provide compelling evidence that gene deletions leading to emotionality phenotypes in the KOMP pipeline have addiction phenotypes. We will subject these lines to deep drug abuse–relevant phenotyping, including drug self-administration, transcriptional profiling from key neuronal tissues, and whole brain imaging. The data from these will be integrated using systems analysis. The successful completion of this project will yield dozens of novel mouse models with detailed transcriptome, and neuroanatomical profile to establish mechanistic insight into this behavioral abnormality. These can serve are a resource for the research community for therapeutics development.