Yamamoto N, Parhar I S, Sawai N, Oka Y, Ito H
Department of Anatomy, Nippon Medical School, Tokyo, Japan.
Neurosci Res. 1998 May;31(1):31-8. doi: 10.1016/s0168-0102(98)00022-4.
In most teleosts, there are three groups of gonadotropin-releasing hormone (GnRH) neurons. In this study we addressed the question of GnRH neuronal innervation of the pituitary in the dwarf gourami and the tilapia using immunocytochemistry combined with biocytin tract tracing. Biocytin was applied to the pituitary attached to the brain in vitro. Similar results were obtained in both species. GnRH neurons retrogradely labeled with biocytin were observed only in the preoptic area. These results indicate that preoptic GnRH neurons innervate the pituitary. Negative labeling of biocytin in the terminal-nerve and midbrain GnRH neurons suggests that these two GnRH neuronal populations do not project to the pituitary. Biocytin-positive but GnRH-negative neurons were also observed in the preoptic area and the ventromedial parts of the hypothalamus, suggesting neuropeptidergic and aminergic innervation of the pituitary besides GnRH.
在大多数硬骨鱼中，存在三组促性腺激素释放激素（GnRH）神经元。在本研究中，我们使用免疫细胞化学结合生物胞素束路追踪技术，探讨了侏儒斗鱼和罗非鱼垂体的GnRH神经元支配问题。将生物胞素应用于体外与脑相连的垂体。在两个物种中均获得了相似的结果。仅在视前区观察到用生物胞素逆行标记的GnRH神经元。这些结果表明视前GnRH神经元支配垂体。终末神经和中脑GnRH神经元中生物胞素的阴性标记表明这两个GnRH神经元群体不投射到垂体。在视前区和下丘脑腹内侧部分也观察到生物胞素阳性但GnRH阴性的神经元，这表明除了GnRH外，垂体还存在神经肽能和胺能支配。
