Collin F, Chartrel N, Fasolo A, Conlon J M, Vandesande F, Vaudry H
European Institute for Peptide Research, Laboratory of Cellular and Molecular Neuroendocrinology, INSERM U 413, UA CNRS, University of Rouen, Mont-Saint-Aignan, France.
Brain Res. 1995 Dec 12;703(1-2):111-28. doi: 10.1016/0006-8993(95)01074-2.
Two molecular forms of gonadotropin-releasing hormone (GnRH) have been recently characterized in the brain of the frog Rana ridibunda i.e. mammalian GnRH (mGnRH) and chicken GnRH-II (cGnRH-II). Using highly specific antisera against each form of GnRH, we have investigated the distribution of these two neuropeptides in the frog brain by the indirect immunofluorescence and the peroxidase-antiperoxidase techniques. mGnRH-immunoreactive cell bodies were restricted to a well defined region corresponding to the septal-anterior preoptic area. mGnRH-containing fibers projected through the ventral diencephalon and ended in the median eminence. In contrast, cGnRH-II-immunoreactive structures were widely distributed in the frog brain. In the telencephalon cGnRH-II-positive elements formed a ventromedial column extending from the olfactory bulb to the septal area, a pathway which corresponds to the terminal nerve. A dense accumulation of cGnRH-II-immunoreactive cell bodies was also found in the septal-anterior preoptic area; these neurons sent processes towards the median eminence via the hypothalamus. Double immunostaining revealed that, in this area, mGnRH- and cGnRH-II-like immunoreactivity co-existed in the same neurons. In the mid-diencephalon, numerous cGnRH-II-immunoreactive perikarya were found, surrounding the third ventricle, in the posterior preoptic and infundibular areas. Many of these neurons sent processes towards the ventricular cavity. More caudally, a dense population of cGnRH-II-immunoreactive perikarya was also observed in the nucleus of the paraventricular organ and the posterior tubercle. Dorsally, the thalamus, the tegmentum, the tectum and the granular layer of the cerebellum were richly innervated by cGnRH-II-positive fibers. In the medulla oblongata, numerous cGnRH-II-immunoreactive perikarya were seen in several cranial nerve nuclei. Ventrally, a dense plexus of immunoreactive fibers projected rostrocaudally into the spinal cord. The occurrence of mGnRH- and cGnRH-II-like immunoreactivity in the septal-anterior preoptic area and the hypothalamo-pituitary pathway supports the view that both peptides act as hypophysiotropic neurohormones. The widespread distribution of cGnRH-II-immunoreactive elements in the central nervous system of the frog strongly suggests that this peptide may also exert neuromodulator and/or neurotransmitter activities.
最近在欧洲林蛙大脑中鉴定出了促性腺激素释放激素（GnRH）的两种分子形式，即哺乳动物GnRH（mGnRH）和鸡GnRH-II（cGnRH-II）。我们使用针对每种GnRH形式的高度特异性抗血清，通过间接免疫荧光和过氧化物酶-抗过氧化物酶技术研究了这两种神经肽在蛙脑中的分布。mGnRH免疫反应性细胞体局限于一个明确界定的区域，对应于隔区-视前区前部。含mGnRH的纤维穿过腹侧间脑并终止于正中隆起。相比之下，cGnRH-II免疫反应性结构在蛙脑中广泛分布。在端脑中，cGnRH-II阳性成分形成一个从嗅球延伸至隔区的腹内侧柱，这一通路对应于终神经。在隔区-视前区前部也发现了大量cGnRH-II免疫反应性细胞体的聚集；这些神经元通过下丘脑向正中隆起发出突起。双重免疫染色显示，在该区域，mGnRH样和cGnRH-II样免疫反应性共存于同一神经元中。在间脑中部，在视前区后部和漏斗区围绕第三脑室发现了许多cGnRH-II免疫反应性核周体。这些神经元中的许多向脑室腔发出突起。更靠尾侧的部位，在室旁器官核和后结节中也观察到大量cGnRH-II免疫反应性核周体。在背侧，丘脑、被盖、顶盖和小脑颗粒层有丰富的cGnRH-II阳性纤维支配。在延髓中，在几个脑神经核中可见许多cGnRH-II免疫反应性核周体。在腹侧，密集的免疫反应性纤维丛向尾头方向投射到脊髓中。隔区-视前区前部和下丘脑-垂体通路中mGnRH样和cGnRH-II样免疫反应性的存在支持了这两种肽都作为促垂体神经激素起作用的观点。cGnRH-II免疫反应性成分在蛙中枢神经系统中的广泛分布强烈表明，该肽也可能发挥神经调节和/或神经递质活性。
