Recent years have seen a barrage of reports that link the neuropeptides vasopressin and oxytocin to the control of various social behaviors and a variety of other functions. For most of these functions, it is unknown specifically which neurons secrete the neuropeptides that influence them. This project aims to systematically trace vasopressin and oxytocin innervation of the brain, using a variety of endocrine, genetic, and neuroanatomical methods. This will provide a map of vasopressin and oxytocin innervation useful for anybody that studies these peptides. The project will also develop a strategy to test the function of specific sets of neuropeptide neurons, by manipulating vasopressin production in select projections to test the hypothesis that the sexually dimorphic vasopressin innervation of the brain controls social recognition memory. Neuropeptides such as vasopressin and oxytocin are often characterized as modulators of synaptic transmission. In that respect, they are in a very good position to serve as "gatekeepers," i.e., as substances that control the flow of information in the brain, thereby influencing the likelihood that certain behaviors or homeostatic events take place. Although neuropeptides have been implicated in many different functions, the effects of neuropeptides are typically better known than the underlying anatomy. In other words, it is unclear where the gates are that are being kept and also which neurons control these gates. By addressing this issue for vasopressin, this project will provide a roadmap for studying the function of neuropeptides in general. Typically, about five undergraduates work in the PI's laboratory. In addition, undergraduate students from colleges with traditionally large proportions of minority students have spent the summer months doing research in the laboratory and will continue to do so. These students will participate in this project, as will at least one graduate student and one postdoctoral trainee.
