Centre for Neuroendocrinology and Department of Physiology, University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
J Comp Neurol. 2011 Dec 1;519(17):3456-69. doi: 10.1002/cne.22716.
It is now well established that the kisspeptin neurons of the hypothalamus play a key role in regulating the activity of gonadotropin-releasing hormone (GnRH) neurons. The population of kisspeptin neurons residing in the rostral periventricular region of the third ventricle (RP3V), encompassing the anteroventral periventricular (AVPV) and periventricular preoptic nuclei (PVpo), are implicated in the generation of the preovulatory GnRH surge mechanism and puberty onset in female rodents. The present study examined whether these kisspeptin neurons may express other neuropeptides in the adult female mouse. Initially, the distribution of galanin, neurotensin, met-enkephalin (mENK), and cholecystokinin (CCK)-immunoreactive cells was determined within the RP3V of colchicine-treated mice. Subsequent experiments, using a new kisspeptin-10 antibody raised in sheep, examined the relationship of these neuropeptides to kisspeptin neurons. No evidence was found for expression of neurotensin or CCK by RP3V kisspeptin neurons, but subpopulations of kisspeptin neurons were observed to express galanin and mENK. Dual-labeled RP3V kisspeptin/galanin cells represented 7% of all kisspeptin and 21% of all galanin neurons whereas dual-labeled kisspeptin/mENK cells represented 28-38% of kisspeptin neurons and 58-68% of the mENK population, depending on location within the AVPV or PVpo. Kisspeptin neurons in the arcuate nucleus were also found to express galanin but not mENK. These observations indicate that, like the kisspeptin population of the arcuate nucleus, kisspeptin neurons in the RP3V also co-express a range of neuropeptides. This pattern of co-expression should greatly increase the dynamic range with which kisspeptin neurons can modulate the activity of their afferent neurons.
现在已经证实，下丘脑的 kisspeptin 神经元在调节促性腺激素释放激素（GnRH）神经元的活性方面起着关键作用。位于第三脑室（RP3V）前室旁区的 kisspeptin 神经元群，包括前腹室旁核（AVPV）和室旁前核（PVpo），参与了雌性啮齿动物的促性腺激素释放激素（GnRH）的排卵前激增机制和青春期的发生。本研究检查了这些 kisspeptin 神经元是否可以在成年雌性小鼠中表达其他神经肽。最初，在秋水仙碱处理的小鼠中，确定了 RP3V 中甘丙肽、神经降压素、甲硫氨酸脑啡肽（mENK）和胆囊收缩素（CCK）免疫反应细胞的分布。使用在绵羊中产生的新型 kisspeptin-10 抗体进行的后续实验，研究了这些神经肽与 kisspeptin 神经元的关系。没有证据表明 RP3V kisspeptin 神经元表达神经降压素或 CCK，但观察到 kisspeptin 神经元的亚群表达甘丙肽和 mENK。RP3V kisspeptin/甘丙肽双标记细胞代表所有 kisspeptin 的 7%和所有甘丙肽神经元的 21%，而 kisspeptin/mENK 双标记细胞分别代表 kisspeptin 神经元的 28-38%和 mENK 群体的 58-68%，具体取决于 AVPV 或 PVpo 内的位置。弓状核中的 kisspeptin 神经元也被发现表达甘丙肽而不表达 mENK。这些观察结果表明，与弓状核中的 kisspeptin 群体一样，RP3V 中的 kisspeptin 神经元也共同表达一系列神经肽。这种共表达模式应该大大增加 kisspeptin 神经元调节其传入神经元活性的动态范围。
