Steroid synthesis and action in the vertebrate CNS. My laboratory is interested in the hormonal control of brain and behavior. Steroid hormones influence the CNS in diverse ways, from regulating neuronal transcription, to influencing cell signaling pathways, to direct modulation of neurotransmitter receptor ion channels. The traditional view is that neurally active steroids come from the gonads and adrenals, but we and others have evidence that in some cases, steroids can be synthesized directly in the brain. We are testing this hypothesis in songbirds that have a variety of well-characterized endpoints of steroid action on brain including organizing neural circuits developmentally, activating circuits and stimulating persistent neural plasticity in adults. We utilize molecular, biochemical and neuroanatomical approaches to explore the expression, activity and function of steroid synthetic enzymes. In addition, we do field research on birds, including one called the Golden-collared manakin that lives in the rainforests of Panama. Males of this species have a remarkable, acrobatic and noisy courtship display. We study how hormones act on the brain, spinal cord and peripheral muscles to give males the ability to perform these elaborate displays.