Tobari Yasuko, Tsutsui Kazuyoshi
Laboratory of Animal Genetics and Breeding, Department of Animal Science and Biotechnology, School of Veterinary Medicine, Azabu University, Sagamihara, Japan.
Laboratory of Integrative Brain Sciences, Department of Biology, Waseda University, Tokyo, Japan.
Front Endocrinol (Lausanne). 2019 Apr 24;10:243. doi: 10.3389/fendo.2019.00243. eCollection 2019.
The social environment changes circulating hormone levels and associated behavior in animals. Although social information is perceived by sensory systems in the brain, and peripheral reproductive hormonal levels are regulated mainly by the hypothalamus-pituitary-gonadal (HPG) axis, the neurochemical systems that convey social information to the HPG axis were not well-understood until the 2000s. In recent years, a growing body of evidence has demonstrated that a neuropeptide localized in the hypothalamus, gonadotropin-inhibitory hormone (GnIH), is responsive to social information. GnIH was first identified in the quail hypothalamo-hypophyseal system and named for its ability to inhibit gonadotropin secretion. Hypothalamic GnIH neurons have thus begun to be regarded as integrators, translating social information into changes in the levels of circulating gonadal hormones through the HPG axis. Here, we review current research investigating the responses of the GnIH neuronal systems to social status, offspring, and the presence/absence of conspecifics, and describe the neurochemical pathways linking visual perception of a potential mate to a rapid change in blood gonadotropin levels via the hypothalamus-pituitary axis in male birds.
社会环境会改变动物体内循环激素的水平以及相关行为。尽管大脑中的感觉系统能够感知社会信息，并且外周生殖激素水平主要由下丘脑-垂体-性腺（HPG）轴调节，但是直到21世纪，将社会信息传递给HPG轴的神经化学系统仍未被充分理解。近年来，越来越多的证据表明，下丘脑定位的一种神经肽——促性腺激素抑制激素（GnIH），对社会信息有反应。GnIH最初是在鹌鹑下丘脑-垂体系统中被鉴定出来的，并因其抑制促性腺激素分泌的能力而得名。因此，下丘脑GnIH神经元开始被视为整合器，通过HPG轴将社会信息转化为循环性腺激素水平的变化。在这里，我们综述了当前关于GnIH神经元系统对社会地位、后代以及同种个体的存在与否的反应的研究，并描述了雄性鸟类中通过下丘脑-垂体轴将潜在配偶的视觉感知与血液促性腺激素水平的快速变化联系起来的神经化学途径。
