title: Kisspeptin and GnRH pulse generation.
abstract: The reproductive neuropeptide gonadotropin-releasing hormone (GnRH) has two modes of secretion. Besides the surge mode, which induces ovulation in females, the pulse mode of GnRH release is essential to cause various reproductive events in both sexes, such as spermatogenesis, follicular development, and sex steroid synthesis. Some environmental cues control gonadal activities through modulating GnRH pulse frequency. Researchers have looked for the anatomical location of the mechanism generating GnRH pulses, the GnRH pulse generator, in the brain, because an artificial manipulation of GnRH pulse frequency is of therapeutic importance to stimulate or suppress gonadal activity. Discoveries of kisspeptin and, consequently, KNDy (kisspeptin/neurokinin B/dynorphin) neurons in the hypothalamus have provided a clue to the possible location of the GnRH pulse generator. Our analyses of hypothalamic multiple-unit activity revealed that KNDy neurons located in the hypothalamic arcuate nucleus might play a central role in the generation of GnRH pulses in goats, and perhaps other mammalian species. This chapter further discusses the possible mechanisms for GnRH pulse generation.
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan. hokamu@affrc.go.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okamura
authors.forename: Hiroko
authors.initials: H
authors.lastname: Tsukamura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ohkura
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Uenoyama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Wakabayashi
authors.forename: Kei-ichiro
authors.initials: K
authors.lastname: Maeda
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000378:metabolism*; D004399:Dynorphins / Q000378:metabolism; D005260:Female; D006041:Goats; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D006801:Humans; D059648:Kisspeptins / Q000378:metabolism*; D008297:Male; D015287:Neurokinin B / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D010060:Ovulation / Q000502:physiology*; D013091:Spermatogenesis / Q000502:physiology*
chemical_list: C106628:KISS1 protein, human; D059648:Kisspeptins; D007987:Gonadotropin-Releasing Hormone; D004399:Dynorphins; D015287:Neurokinin B