Endocrine Abstracts

The status of the neuroendocrine reproductive axis differs between various stages of development and adulthood, and also differs between the sexes, including earlier onset of sexual maturation in females than males and the ability to generate a preovulatory gonadotropin surge in adult females but not adult males. The reproductive axis is controlled by various hormonal and neural pathways that converge upon forebrain GnRH neurons, and many of the developmental and sex differenc...

We recently identified a group of neurons in the arcuate nucleus of the mammalian hypothalamus that co-localize three neuropeptides, kisspeptin, neurokinin B and dynorphin, each of which has been shown to play a critical role in the central control of reproduction. Growing evidence suggests that this subpopulation, abbreviated as the ‘KNDy’ subpopulation, plays a key role in mediating hormonal feedback control of GnRH secretion. KNDy cells are a major target for ster...

Ovarian estrogens exert critically important actions in hypothalamic neurons to regulate ovulatory cyclicity, reproductive behaviors, and energy homeostasis. Estrogen receptor alpha (ERα) appears to mediate most of these effects, as disruption of ER signaling leads to infertility and metabolic syndrome. ER signaling mechanisms may include ‘classical genotropic’ effects mediated by direct binding of receptor dimers to DNA, ‘non-classical genotropic’ eff...

Insulin has been shown to participate in the long-term regulation of satiety, and it is emerging as a peripheral modulator of the activity of the neuroendocrine reproductive axis as well. Following the observation that mice lacking the expression of brain insulin receptors exhibit central hypogonadism and infertility, we could show that peripheral insulin can stimulate LH secretion in rodents. This effect is likely mediated at the level of the hypothalamus, as suggested by the...