The effects of chronic prenatal exposure to carbon monoxide (CO) upon neonatal and post-weanling development will be examined in the rat. The principal objective of this project is to determine whether low level prenatal environmental CO exposure equivalent to that experienced by fetuses of cigarette smoking women can have permanent neurobiological effect on the offspring. An ancillary objective will be the determination of a threshold level below which such exposure has no measurable effects. The proposed studies concentrate upon development of the central nervous system, but include some studies of peripheral organs as well. The principal levels of analysis include spontaneous behavioral assessments as well as responses to centrally acting drugs, histochemical fluorescence studies of developing monoamine systems in the brain, determination of brain and organ development through protein and DNA analyses, and neurochemical studies designed to measure perturbations in monoamine systems resulting from prenatal hypoxia.