Neurobiological study of fish brains gives insights into the nature of gonadotropin-releasing hormone 1-3 neurons.
Neurobiological study of fish brains gives insights into the nature of gonadotropin-releasing hormone 1-3 neurons.
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DOI：
10.3389/fendo.2013.00177
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发表时间：
2013-11-19
影响因子：
5.2
通讯作者：
Oka Y
中科院分区：
文献类型：
--
作者：
Karigo T;Oka Y
越来越多的证据表明，一种脊椎动物大脑中解剖学上不同的 GnRH 神经元组表达了由 gnrh 基因的不同旁系同源物编码的多达三种不同分子种类的 GnRH 肽。它们被称为 gnrh1、gnrh2 和 gnrh3。来自分子、解剖学和生理学实验的最新证据强烈表明，每个 GnRH 系统的功能都不同。在此，我们回顾了三种不同GnRH神经元系统功能研究的最新进展，主要集中于GnRH绿色荧光蛋白（GFP）转基因动物的电生理分析。引入 GFP 转基因动物对 GnRH 神经元进行电生理分析极大地提高了我们对其解剖学和电生理学的认识，特别是 gnrh1 神经元，由于其尺寸小且分布分散，长期以来一直无法对单个神经元进行详细的电生理分析。基于最近的研究结果，我们提出不同的电生理特性，特别是电活动的自发模式及其随时间的变化，以及轴突投射表征了GnRH1-3神经元的不同功能； GnRH1 神经元充当促垂体神经内分泌调节剂，GnRH2 和 GnRH3 神经元在大脑广泛区域充当神经调节剂。
Accumulating evidence suggests that up to three different molecular species of GnRH peptides encoded by different paralogs of gnrh genes are expressed by anatomically distinct groups of GnRH neurons in the brain of one vertebrate species. They are called gnrh1, gnrh2, and gnrh3. Recent evidence from molecular, anatomical, and physiological experiments strongly suggests that each GnRH system functions differently. Here, we review recent advancement in the functional studies of the three different GnRH neuron systems, mainly focusing on the electrophysiological analysis of the GnRH-green fluorescent protein (GFP) transgenic animals. The introduction of GFP-transgenic animals for the electrophysiological analysis of GnRH neurons greatly advanced our knowledge on their anatomy and electrophysiology, especially of gnrh1 neurons, which has long defied detailed electrophysiological analysis of single neurons because of their small size and scattered distribution. Based on the results of recent studies, we propose that different electrophysiological properties, especially the spontaneous patterns of electrical activities and their time-dependent changes, and the axonal projections characterize the different functions of GnRH1-3 neurons; GnRH1 neurons act as hypophysiotropic neuroendocrine regulators, and GnRH2 and GnRH3 neurons act as neuromodulators in wide areas of the brain.