Neural interaction of gonadotropin-regulating hormone immunoreactive neurons and the suprachiasmatic nucleus with the paraventricular organ in the Japanese grass lizard (Takydromus Tachydromoides)
Neural interaction of gonadotropin-regulating hormone immunoreactive neurons and the suprachiasmatic nucleus with the paraventricular organ in the Japanese grass lizard (Takydromus Tachydromoides)
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DOI：
10.2108/zsj.23.277
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发表时间：
2006-03-01
影响因子：
0.9
通讯作者：
Tamotsu, Satoshi
中科院分区：
文献类型：
--
作者：
Kawano, Emi;Takahata, Yoko;Tamotsu, Satoshi
我们以前的研究表明，室旁器（PVO）在下丘脑的日本草蜥（Takydromus tachydromoides）的光信号转导G蛋白，transformin的免疫反应。这一发现表明PVO是该物种深脑光感受器的候选者。为了了解PVO的功能，我们研究了转导素、5-羟色胺、促性腺激素释放激素（GnRH）和促性腺激素抑制激素（GnIH）在蜥蜴脑中的分布。我们用化学方法证实了PVO神经元中transducin和5-羟色胺的共定位，显示了脑脊液（CSF）接触神经元的结构特征。GnRH免疫反应阳性细胞分布于下丘脑后连合和外侧区。从PVO延伸到下丘脑外侧区的一些GnRH-ir纤维与GnRH-ir细胞体接触。GnIH-ir细胞定位于延髓外侧核、室旁核和上髓质，室旁核的GnIH-ir纤维与PVO内的GnIH-ir神经元的外侧突相接触。此外，我们还发现PVO发出的神经纤维延伸至视交叉上核（SCN），逆行追踪法证实PVO向SCN投射。这些结果表明，PVO通过5-羟色胺介导的神经支配，在日本草蜥垂体功能和生物钟的调节中起重要作用。
Our previous study demonstrated that the paraventricular organ (PVO) in the hypothalamus of the Japanese grass lizard (Takydromus tachydromoides) showed immunoreactivity against the light signal-transducing G-protein, transducin. This finding suggested that the PVO was a candidate for the deep-brain photoreceptor in this species. To understand functions of the PVO, we investigated distributions of transducin, serotonin, gonadotropin-releasing hormone (GnRH), and gonadotropin-inhibitory hormone (GnIH) in the lizard's brain. We immunohistochemically confirmed co-localization of transducin and serotonin in PVO neurons that showed structural characteristics of cerebrospinal fluid (CSF)-contacting neurons. GnRH-immunoreactive (ir) cells were localized in the posterior commissure and lateral hypothalamic area. Some of the serotonin-ir fibers extending from the PVO to the lateral hypothalamic area contacted the GnRH-ir cell bodies. GnIH-ir cells were localized in the nucleus accumbens, paraventricular nucleus, and upper medulla, and GnIH-ir fibers from the paraventricular nucleus contacted the lateral processes of serotonin-ir neurons in the PVO. In addition, we found that serotonin-ir fibers from the PVO extended to the suprachiasmatic nucleus (SCN), and the retrograde transport method confirmed the PVO projections to the SCN. These findings suggest that the PVO, by means of innervation mediated by serotonin, plays an important role in the regulation of pituitary function and the biological clock in the Japanese grass lizard.