Figure 2: Estrous cycle influences the effects of optogenetic stimulation of kisspeptin neurons.
During estrus, circulating estrogens are elevated while progestin levels are decreasing, and optogenetic stimulation of kisspeptin neurons stimulates luteinizing hormone (LH) release. During diestrus estrogen levels are lower while progestin levels are higher, and optogenetic stimulation of kisspeptin neurons does not stimulate GnRH release.