Physiology and release activity of GnRH neurons

Abstract

This chapter discusses the physiology and release activity of gonadotropin-releasing hormone (GnRH) neurons. The GnRH was first isolated from the mammalian hypothalamus and was originally identified as a hypophysiotropic decapeptide hormone that facilitates gonadotropin release from the pituitary gonadotropes. It is possible to study, in a semi-intact whole brain, the physiology, morphology, and cell biology of single GnRH neurons by taking advantage of the in vitro experimental conditions. Because the GnRH neuronal cell bodies in most vertebrate species are small and diffusely distributed in various brain regions, it is extremely difficult to study various features of single GnRH neurons. Therefore, the dwarf gourami clearly has experimental advantages over other vertebrates to study the cellular physiology and morphology of GnRH neurons. It has been recognized recently that there are also diversity of GnRH receptors, and the functional and evolutionary significance of such diversity of GnRH ligand and receptors is attracting more and more attention.