Patterns of steroid hormone effects on electrical and molecular events in hypothalamic neurons.

Hypothalamic neurons with nuclear receptors for steroid hormones provide opportunities to relate individual biosynthetic and electrical changes to hormone-driven behaviors. Successful work with female rodent reproductive behavior has proven that it is possible to define a neural circuit for a vertebrate behavior. In contrast to what might be expected from an invertebrate system, results from several approaches to neuronal gene expression show the complexity of hypothalamic control, even over this simple mammalian behavior. This is not a 1 hormone-1 gene-1 behavior system. Neither is there just one mode of hormonal induction. Certain steroid hormone effects can multiply each other, showing how a clear endocrine signal could be discerned among other variations in neural activity.