An exploration of reciprocal interactions between the nervous and endocrine systems: how the brain regulates endocrine homeostasis, and how developmental and daily/seasonal changes in hormone levels bring about changes in neural structure and function. These themes will be covered in an integrative manner that includes analysis at molecular, cellular, systems, and organismal levels. Topics will include hormone and receptor structure-function relationships, pharmacology, neuroendocrine techniques, neuroendocrine systems, gonadal hormones and sex differences during development and adulthood, the neuroendocrine regulation of social behaviors, and the hippocampal-hypothalamic-pituitary-adrenal stress axis. Laboratory experiments will involve the careful and humane use of vertebrates as research models. Laboratory topics will include behavioral assays, neuroanatomy, hormone analyses, brain tissue histology, brain tissue immunohistochemistry, and microscopy. Laboratories are scheduled for 4 hours each week.