Figure 11.

Kisspeptin excites POMC cells. In this diagram, kisspeptin release excites POMC cells by activation of a Na–Ca exchanger and nonselective cation current. Kisspeptin inhibits NPY neurons by an indirect action of increasing GABA release, either from POMC cells or from other GABA cells. GnIH and NPY, found in axons innervating POMC neurons, both attenuate kisspeptin-mediated excitation by a mechanism based on hyperpolarization and an outward potassium current. Both kisspeptin and GnIH axons also regulate GnRH neurons directly, as studied in other papers cited in Discussion. The projection of POMC and NPY neurons to GnRH cells is not shown here.