The onset of puberty becomes official when gonadotropin-releasing hormone (GnRH) is secreted and sets off a chain reaction of chemical messages. Inside the hypothalamus, nerve cells release GnRH in a 'round-the-clock,' pulsatile fashion. With each secretion, the pituitary gland is stimulated to secrete its own messengers, lutenizing hormone (LH) and follicle-stimulating hormone (FSH), directly into the circulation. In turn, these rising levels of LH and FSH cause the testes and ovaries to produce the sex hormones testosterone and estradiol, the culprits responsible for the physical changes and emotional baggage of male and female puberty, respectively.
"We now have very good evidence that the GPR54 gene and its switch, the kisspeptin protein molecule produced by KiSS-1, are key to the initiation of puberty, when GnRH is released," Dr. Plant said. "However, it's unlikely that they act alone. Other signaling systems, some of which have probably yet to be identified in humans, help control GnRH release in primates."
Besides learning that GPR54 and KiSS-1 are expressed inside the hypothalamus of primates at the time of puberty, the researchers also found that by giving animals kisspeptin they could, essentially wake up the reproductive hormones from their childhood hibernation. Within 30 minutes of kisspeptin being administered to male monkeys, LH, one of the hormones stimulated by GnRH secretion, was no longer dormant, with levels 25-times
Source:University of Pittsburgh Medical Center