Suppr超能文献

节律依赖性光诱导火鸡下丘脑乳头前核内促性腺激素释放激素-I的表达及多巴胺能神经元的激活。

Rhythmic dependent light induction of gonadotrophin-releasing hormone-I expression and activation of dopaminergic neurones within the premammillary nucleus of the turkey hypothalamus.

作者信息

Thayananuphat A, Kang S W, Bakken T, Millam J R, El Halawani M E

机构信息

Department of Animal Science, University of Minnesota, St Paul, MN 55108, USA.

出版信息

J Neuroendocrinol. 2007 Jun;19(6):399-406. doi: 10.1111/j.1365-2826.2007.01545.x.

Abstract

Our previous studies using turkey hens have demonstrated that c-fos mRNA (a marker of neuronal activation) is expressed in gonadotrophin-releasing hormone-I (GnRH-I), vasoactive intestinal peptide (VIP) and dopamine (DA) neurones following electrical stimulation in the preoptic area. DA has been shown to have both stimulatory and inhibitory effects on the GnRH-I/luteinising hormone (LH), follicle-stimulating hormone (FSH) and VIP/prolactin (PRL) systems. To identify the DA neurones that mediate the stimulatory influences of photoperiod on the reproductive system, we examined c-fos mRNA induction in DA, GnRH-I, and VIP neurones in the turkey hypothalamus using a dark-interruption experimental design. A 30-min light period was provided to short day (6L : 18D) photosensitive turkeys at times when birds were responsive to light (14 h after first light) and at times when birds were unresponsive to light (8 h and 20 h after first light). The only area where DA neurones were activated when the birds were provided with light was in the nucleus premammillaris (PMM). The number of activated DA neurones was significantly greater when light was provided at 14 h (during the photoinducible phase) than at 8 h or 20 h. At 14 h, there was also an increase in the number of GnRH-I neurones activated in the area of the nucleus commissura pallii (nCPa), as well as an up-regulation of GnRH-I mRNA expression. No expression of c-fos mRNA was observed in VIP neurones in the nucleus infundibularis or up-regulation of VIP mRNA expression in any of the experimental light treatments. These results are the first evidence to demonstrate a relationship between the dopaminergic system in the PMM and the GnRH-I system in the nCPa during the photoinduction of avian reproductive activity.

摘要

我们之前使用母火鸡进行的研究表明,在视前区进行电刺激后,促性腺激素释放激素-I(GnRH-I)、血管活性肠肽(VIP)和多巴胺(DA)神经元中会表达c-fos mRNA(神经元激活的标志物)。已表明DA对GnRH-I/促黄体生成素(LH)、促卵泡激素(FSH)和VIP/催乳素(PRL)系统具有刺激和抑制作用。为了确定介导光周期对生殖系统刺激作用的DA神经元,我们采用暗中断实验设计,研究了火鸡下丘脑DA、GnRH-I和VIP神经元中c-fos mRNA的诱导情况。在短日照(6L:18D)光敏火鸡对光有反应时(首次光照后14小时)以及对光无反应时(首次光照后8小时和20小时),提供30分钟的光照期。当给火鸡提供光照时,DA神经元唯一被激活的区域是乳头前核(PMM)。在14小时(光诱导期)提供光照时,激活的DA神经元数量显著多于8小时或20小时。在14小时时,苍白球连合核(nCPa)区域激活的GnRH-I神经元数量也增加,同时GnRH-I mRNA表达上调。在任何实验性光照处理中,漏斗核中的VIP神经元均未观察到c-fos mRNA表达,也未观察到VIP mRNA表达上调。这些结果首次证明了在鸟类生殖活动光诱导过程中,PMM中的多巴胺能系统与nCPa中的GnRH-I系统之间存在关联。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验