title: In Utero Development of Kisspeptin/GnRH Neural Circuitry in Male Mice.
abstract: The neuropeptide kisspeptin is a major regulator of the hypothalamus-pituitary-gonadal axis. Although it has long been known that kisspeptin and its receptor G protein-coupled receptor 54 (GPR54) are expressed in the developing brain well before puberty onset, the potential role of kisspeptin/GPR54 signaling in the embryonic brain has remained mysterious. Recent studies in female mice have shown that kisspeptin neurons in the arcuate nucleus of the hypothalamus (ARC) already communicate with a subset of GnRH neurons in utero. Whether this specific neural circuit is also formed in the developing male brain is not known. Here, we used a combination of different genetic strategies to analyze the ontogeny and development of the kisspeptin/GPR54 system in the male mouse brain. We demonstrate orchestrated onset of kisspeptin and GPR54 expression in the male embryonic mouse brain and find that androgen receptor and estrogen receptor-α immunoreactivity within the male brain delineate the birthplace of kisspeptin neurons in the ARC. Using conditional transsynaptic tracing from kisspeptin neurons, we find that ARC kisspeptin neurons already communicate with a subset of GnRH neurons in utero and that the neural circuits between ARC kisspeptin and GnRH neurons in the male mouse brain are established before birth. Furthermore, we also show that the connectivity between kisspeptin and GnRH neurons does not depend on the spatial position of GnRH neurons. Our data delineate the maturing neural circuits underlying control of the reproductive axis in the male embryonic mouse brain.
authors.affiliation: Department of Pharmacology and Toxicology (D.K., V.P., U.B.), University of Saarland School of Medicine, D-66421 Homburg, Germany; and Institute for Neural Signal Transduction (M.F., A.V.), Center for Molecular Neurobiology, Falkenried 94, D-20253 Hamburg, Germany.
authors.forename: Devesh
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Department of Pharmacology and Toxicology (D.K., V.P., U.B.), University of Saarland School of Medicine, D-66421 Homburg, Germany; and Institute for Neural Signal Transduction (M.F., A.V.), Center for Molecular Neurobiology, Falkenried 94, D-20253 Hamburg, Germany.
authors.forename: Vinod
authors.initials: V
authors.lastname: Periasamy
authors.affiliation: Department of Pharmacology and Toxicology (D.K., V.P., U.B.), University of Saarland School of Medicine, D-66421 Homburg, Germany; and Institute for Neural Signal Transduction (M.F., A.V.), Center for Molecular Neurobiology, Falkenried 94, D-20253 Hamburg, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Freese
authors.affiliation: Department of Pharmacology and Toxicology (D.K., V.P., U.B.), University of Saarland School of Medicine, D-66421 Homburg, Germany; and Institute for Neural Signal Transduction (M.F., A.V.), Center for Molecular Neurobiology, Falkenried 94, D-20253 Hamburg, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Voigt
authors.affiliation: Department of Pharmacology and Toxicology (D.K., V.P., U.B.), University of Saarland School of Medicine, D-66421 Homburg, Germany; and Institute for Neural Signal Transduction (M.F., A.V.), Center for Molecular Neurobiology, Falkenried 94, D-20253 Hamburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Boehm
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000196:embryology* / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000378:metabolism; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D059648:Kisspeptins / Q000378:metabolism*; D008297:Male; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000502:physiology; D011247:Pregnancy; D011944:Receptors, Androgen / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D000074502:Receptors, Kisspeptin-1
chemical_list: D047628:Estrogen Receptor alpha; C491407:Kiss1 protein, mouse; C492248:Kiss1r protein, mouse; D059648:Kisspeptins; D011944:Receptors, Androgen; D043562:Receptors, G-Protein-Coupled; D000074502:Receptors, Kisspeptin-1; D007987:Gonadotropin-Releasing Hormone