The onset of puberty, the developmental stage at which adolescents reach sexual maturity, is known to be associated with the activity of a specific class of neurons, namely gonadotropin-releasing hormone (GnRH) neurons. Past neuroscience research revealed that while these neurons are already activated before humans and other mammals are born, they then remain dormant until puberty. A new study published in the Journal of Neuroscience now provides molecular insight into the mechanism controlling the activity of the emerging reproductive neural circuitry in the mouse brain.