GNRH1 and hypogonadotropic hypogonadism: Sirt1 deacetylates cortactin to drive in vitro GnRH neuronal migration, and GnRH neurons in Sirt1−/− mice loss migration from vomeronasal organ to colonize in hypothalamus, leading to hypogonadotropic hypogonadism reminiscent of human congenital Kallmann’s Syndrome that causes male infertility [1,101].