Identification and characterization of a gonadotropin-inhibitory system in the brains of mammals

• Lance J. Kriegsfeld

  *Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720;

• Dan Feng Mei

  Department of Psychology, Columbia University, New York, NY 10027;

• George E. Bentley

  Department of Integrative Biology, University of California, Berkeley, CA 94720; and

• Takayoshi Ubuka

  Department of Integrative Biology, University of California, Berkeley, CA 94720; and

• Alex O. Mason

  *Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720;

• Kazuhiko Inoue

  Laboratory of Brain Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan

• Kazuyoshi Ukena

  Laboratory of Brain Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan

• Kazuyoshi Tsutsui

  Laboratory of Brain Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan

• Rae Silver

  Department of Psychology, Columbia University, New York, NY 10027;

抄録

Successful reproduction requires maintenance of the reproductive axis within fine operating limits through negative feedback actions of sex steroids. Despite the importance of this homeostatic process, our understanding of the neural loci, pathways, and neurochemicals responsible remain incomplete. Here, we reveal a neuropeptidergic pathway that directly links gonadal steroid actions to regulation of the reproductive system. An RFamide (Arg-Phe-NH 2 ) peptide that inhibits gonadotropin release from quail pituitary was recently identified and named gonadotropin-inhibitory hormone (GnIH). Birds are known to have specialized adaptations associated with gonadotropin-releasing hormone (GnRH) regulation to optimize reproduction (e.g., encephalic photoreceptors), and the existence of a hypothalamic peptide inhibiting gonadotropins may or may not be another such specialization. To determine whether GnIH serves as a signaling pathway for sex steroid regulation of the reproductive axis, we used immunohistochemistry and in situ hybridization to characterize the distribution and functional role of this peptide in hamsters, rats, and mice. GnIH-immunoreactive (GnIH-ir) cell bodies are clustered in the mediobasal hypothalamus with pronounced projections and terminals throughout the CNS. In vivo GnIH administration rapidly inhibits luteinizing hormone secretion. Additionally, GnIH-ir neurons form close appositions with GnRH cells, suggesting a direct means of GnRH modulation. Finally, GnIH-ir cells express estrogen receptor-α and exhibit robust immediate early gene expression after gonadal hormone stimulation. Taken together, the distribution of GnIH efferents to neural sites regulating reproductive behavior and neuroendocrine secretions, expression of steroid receptors in GnIH-ir nuclei, and GnIH inhibition of luteinizing hormone secretion indicate the discovery of a system regulating the mammalian reproductive axis.

収録刊行物

• Proceedings of the National Academy of Sciences

  Proceedings of the National Academy of Sciences 103 (7), 2410-2415, 2006-02-07

  Proceedings of the National Academy of Sciences

キーワード

• Multidisciplinary

詳細情報

• CRID: 1360855571571050496
• NII論文ID: 80019314592
• DOI: 10.1073/pnas.0511003103
• ISSN: 10916490
• ISSN: 00278424
• ISSN: http://id.crossref.org/issn/00278424
• Web Site: https://pnas.org/doi/pdf/10.1073/pnas.0511003103
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