Galanin: an unassuming neuropeptide moves to center stage in reproduction.

ABSTRACT

Galanin is a neuropeptide widely distributed throughout the reproductive system, including the brain, pituitary, testes, ovaries, and accessory reproductive tracts of both sexes. Within the hypothalamus, a subset of GnRH-producing neurons also synthesizes galanin. Galanin gene expression in these GnRH neurons is highly inducible by estrogen. Galanin is thought to play an important role in the generation of the preovulatory LH surge, and may serve other functions yet to be discovered.