Figure 2.

Schematic representation of the interaction of systemic metabolic cues with Kisspeptin (KP), orexigenic, and anorexigenic neurons: metabolic cues are secreted by metabolic organs in responses to alterations in metabolic status. Metabolic cues include insulin and glucagon from pancreas, leptin, adiponectin and leptin from adipose tissues, ghrelin from stomach, glucose, fatty acid, cholecystokinin, glucocorticoids, and thyroid hormones, among many others. Alterations in metabolic cues, either directly or indirectly via anorexigenic and orexigenic neurons, modulate KP neuronal activities. KP neurons in turn transfer this information to the HPG axis via gonadotropin-releasing hormone (GnRH) neuronal network. Likewise, orexigenic and anorexigenic neurons can also directly convey current metabolic status related information to GnRH neurons.