Hormones, neural circuits, and vocal communication behaviors

The functional connectivity of neural circuits is shifted dynamically by modulators to allow many, flexible behavioral outputs from the same network. The idea that steroid hormones can operate as genuine neuromodulators - synthesized by and acting in brain circuits within minutes - has gained traction in recent years. Evidence for brain steroid synthesis at synaptic terminals has converged with evidence for the rapid actions of brain-derived steroids on neural circuits and behavior. This talk will emphasize the role of neuro-estrogens as rapid modulators of motor, sensorimotor, and auditory circuits and their accompanying behaviors. It will draw primarily on studies of acoustic communication behaviors in comparative model systems, including teleost fishes and songbirds. The general principle emerging from this work is that the production of steroid hormones within brain circuits can guide behavioral transitions over the course of minutes. Steroids can therefore change the information content of neuronal networks, and this perspective helps explain the substantial influence of steroids on perception, learning and memory.