The hypothalamus is a structure in the brain which is responsible for the regulation of vital physiological systems, the reproductive system being one of these. It does this by releasing gonadotrophin releasing hormone (GnRH) in a pulsatile manner which then acts on the anterior pituitary to result in the pulsatile release of gonadotropins, luteinising hormone (LH) and follicle stimulating hormone (FSH). A group of kisspeptin neurons in the arcuate nucleus of the hypothalamus are termed ?the GnRH pulse generator? as they are responsible for driving the pulsatile release of GnRH and subsequently LH and FSH. These gonadotropins regulate the release of sex hormones progesterone and estrogen in females. These, in turn, relay back to the hypothalamus to stimulate or inhibit their own release, a process known as positive and negative feedback, respectively. My project will aim to investigate how progesterone displays its negative feedback actions on the GnRH pulse generator.