... testosterone increased in response to photostimulation in ad libitum -fed but not in food-restricted birds. Food availability did not, however, affect the plasma testosterone increase resulting from a gonadotropin-releasing hormone-I (GnRH) or a luteinizing hormone (LH) challenge. The number of hypothalamic...

... dynamically regulate gonadal function throughout life. This plasticity is mediated by the brain, where neurons that contain the key reproductive regulatory peptide gonadotropin-releasing hormone (GnRH)change size reversibly depending on male social status. To understand how behavior controls the brain, we...