Rhythm‐Dependent Light Induction of the c‐fos Gene in the Turkey Hypothalamus
Rhythm‐Dependent Light Induction of the c‐fos Gene in the Turkey Hypothalamus
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火鸡下丘脑 c-fos 基因的节律依赖性光诱导
DOI：
10.1111/j.1365-2826.2007.01544.x
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发表时间：
2007
影响因子：
3.2
通讯作者：
M. Halawani
中科院分区：
文献类型：
--
作者：
A. Thayananuphat;S. Kang;T. Bakken;J. R. Millam;M. Halawani
白昼长度（光周期）是温带鸟类生殖神经内分泌活动季节性变化的强大同步器。当在光诱导期暴露于光下时，生殖神经内分泌反应发生。然而，参与鸟类繁殖的神经内分泌系统却知之甚少。我们研究了不同昼夜节律时间的光照对下丘脑和昼夜节律系统组成部分的影响，使用原位杂交测量c - fos mRNA表达，作为光诱导神经元活动的指标。在第一缕光线（主观黎明）出现后的8、14或20小时，暴露于30分钟的光照后（每天光照6小时），比较了这些区域的c‐fos mRNA水平。未受光刺激的对照鸟在同一时间被捕获。在鸟类中，在光诱导期（14小时），与之前或之后相比，c‐fos mRNA在白骨联合核（nCPa）、乳头前核（PMM）、中网膜（ME）和血管终板器官（OVLT）中显著增加。与未受光刺激的对照组相比，光刺激增加了松果体、视交叉上核、视部（vSCN）和下丘脑下核中c‐fos mRNA的表达。然而，无论脉冲发生在黑暗时期的哪个位置，这些区域的反应幅度都是相似的。在任何测试的昼夜节律时间内，在30分钟的光照下，大鼠基底核中没有c‐fos mRNA被诱导。在光诱导阶段，松果体和vSCN在光刺激后缺乏c - fos上调，这证实了这些区域不参与鸟类繁殖的光启动的假设。另一方面，nCPa、ME和OVLT中c - fos mRNA的增加支持了其他研究，表明这些区域参与了长日照引发的生殖行为的发生。本研究提供的新数据表明，尾侧下丘脑的PMM参与了神经介导的、光诱导的火鸡母鸡生殖活动的启动。
Day length (photoperiod) is a powerful synchroniser of seasonal changes in the reproductive neuroendocrine activity in temperate‐zone birds. When exposed to light during the photoinducible phase, reproductive neuroendocrine responses occur. However, the neuroendocrine systems involved in avian reproduction are poorly understood. We investigated the effect of light exposure at different circadian times upon the hypothalamus and components of the circadian system, using c‐fos mRNA expression, measured by in situ hybridisation, as an indicator of light‐induced neuronal activity. Levels of c‐fos mRNA in these areas were compared after turkey hens (on a daily 6‐h light period) had been exposed to a 30‐min period of light occurring at 8, 14, or 20 h after the onset of first light of the day (subjective dawn). Non‐photostimulated control birds were harvested at the same times. In birds, photostimulated within the photoinducibile phase (14 h), in contrast to before or after, c‐fos mRNA was significantly increased in the nucleus commissurae pallii (nCPa), nucleus premamillaris (PMM), eminentia mediana (ME), and organum vasculosum lamina terminalis (OVLT). Photostimulation increased c‐fos mRNA expression in the pineal gland, nucleus suprachiasmaticus, pars visualis (vSCN) and nucleus inferioris hypothalami compared to that of their corresponding nonphotostimulated controls. However, the magnitudes of the responses in these areas were similar irrespective of where in the dark period the pulses occurred. No c‐fos mRNA was induced in the nucleus infundibulari, in response to the 30‐min light period at any of the circadian times tested. The lack of c‐fos up‐regulation in the pineal gland and vSCN following photostimulation during the photoinducible phase lends credence to the hypothesis that these areas are not involved in the photic initiation of avian reproduction. On the other hand, c‐fos mRNA increases in the nCPa, ME, and OVLT support other studies showing that these areas are involved in the onset of reproductive behaviour initiated by long day lengths. The present study provides novel data showing that the PMM in the caudal hypothalamus is involved in the neuronally mediated, light‐induced initiation of reproductive activity in the turkey hen.
影响因子：
56.9
作者：
RALPH, MR;FOSTER, RG;MENAKER, M
通讯作者：
MENAKER, M
人类下丘脑和垂体中的褪黑激素受体：对褪黑激素的昼夜节律和生殖反应的影响。
DOI：
10.1210/jcem.76.2.8381796
发表时间：
1993
期刊：
The Journal of clinical endocrinology and metabolism
影响因子：
--
作者：
Weaver,DR;Stehle,JH;Stopa,EG;Reppert,SM
通讯作者：
Reppert,SM