Hormones secreted from the gonads have a major impact on the behavior of mammals. Most of the behavioral effects of gonadal hormones are thought to be mediated by the central nervous system; however, very little is known about the underlying mechanisms. This project will use a functionally significant communicative behavior of the hamster as a model system to study how gonadal hormones interact with the brain to control behavior. The communicative behavior to be studied, called scent marking, was chosen as a model because one of the neurochemicals (i.e. vasopressin) essential in the central nervous system control of this behavior has been identified and appears to function within a specific site of the brain (i.e. the medial preoptic-anterior hypothalamus). After the effects of gonadal hormones on scent marking behavior have been fully established, this project will investigate whether gonadal hormones influence scent marking by acting on cells which produce or respond to vasopressin within the medial preoptic-anterior hypothalamus. These studies should provide new information on how the nervous and endocrine systems interact to control behavior.
