PROJECT SUMMARY: Neuronal sterol synthesis can be impacted by genetic mutations in cholesterol synthesis genes or by psychopharmaceuticals that inhibit one of the sterol synthesis enzymes (shown in our ongoing studies). Epidemiological studies and our ongoing studies have shown that the use of psychopharmaceuticals during pregnancy is ubiquitous. Many commonly used medications have not been evaluated for safety during pregnancy and the long-term consequences of fetal exposure remain unknown. Testing the effects of commonly prescribed psychopharmaceuticals will provide insight into the role of cholesterol and fatty acids for the formation and maturation of the zebrafish nervous system. We hypothesize that exposure to psychotropic pharmaceuticals that inhibit cholesterol synthesis enzymes will alter neuronal cholesterol and acylcarnitine levels disrupt nervous system development. Zebrafish larvae will be exposed to pharmaceuticals at several distinct developmental stages and analyzed at 5 days post fertilization. LC-MS/MS will be used to measure sterol and oxysterol levels, acylcarnitines, acetylated tubulin, as well as neuronal and glial specific markers. These studies will elucidate the effects of commonly used psychotropic medications on sterol synthesis and acylcarnitine modification and utilization as well as whole body and nervous system development and function in zebrafish larvae. Whole zebrafish and brain immunohistochemistry will be used to visualize drug effects on brain development. In vivo lateral line neurosensory cells and brain neural network electrical activity will be assessed using state-of-the -art technologies available through the COBRE collaboration. Locomotor behavior of drug and control treated zebrafish will be compared using ViewPoint Behavioral Technology. The outcome are threefold: 1. Our results will identify drugs that should be used with extreme caution during pregnancy and provide a framework for future preclinical testing of new therapeutic agents for sterol biosynthesis inhibition; 2. Our results will also provide important information about the role of cholesterol homeostasis and acylcarnitine levels during nervous system development and behavior; and 3. Our results will provide excellent training for graduate and undergraduate research students in the fields of lipid biochemistry, sensory and central nervous system development, physiology, and function by an experienced, dedicated working group of NE-INBRE and COBRE funded scientists.