Fig. 4.

The diagram shows that (a) kisspeptin (Kp) stimulates gonadotrophin-releasing hormone (GnRH) secretion and subsequently gonadotrophin release. Testosterone (T) is aromatised to oestrogen (E), which exerts negative feedback on the anterior pituitary gland and hypothalamus. (b) E exerts negative feedback on GnRH via Kp neurons in the arcuate nucleus (ARC). (c) E exerts positive feedback on GnRH via Kp neurons in the anteroventral periventricular nucleus (AVPV).(25) FSH: follicle-stimulating hormone; LH: luteinising hormone (Adapted from Pinilla et al)(26)