PHOTIC REGULATION OF FOS-LIKE IMMUNOREACTIVITY IN THE SUPRACHIASMATIC NUCLEUS OF THE MOUSE
PHOTIC REGULATION OF FOS-LIKE IMMUNOREACTIVITY IN THE SUPRACHIASMATIC NUCLEUS OF THE MOUSE
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DOI：
10.1002/cne.903240202
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发表时间：
1992-10-08
影响因子：
2.5
通讯作者：
FOSTER, RG
中科院分区：
文献类型：
--
作者：
COLWELL, CS;FOSTER, RG
在哺乳动物中，下丘脑的视交叉上核（SCN）是昼夜节律系统的主要起搏器。已显示光在大鼠和仓鼠的SCN中诱导Fos样免疫反应性（Fos-LI）。本研究的目的是广泛地评价光对小鼠SCN中Fos-LI的影响。给动物短暂的光脉冲，否则在恒定的黑暗中被发现诱导Fos-LI。这种光诱导不受rd突变的影响，rd突变导致光感受器的严重丧失，但不能影响对光的昼夜反应。Fos-LI的光调节依赖于光脉冲施用的昼夜节律周期的阶段。光引起昼夜节律系统相移的相位允许Fos-LI诱导（CT 16和24），而光不引起相移的相位不允许（CT 6和9）。还描述了CT 16时诱导的时间过程。在光/暗周期中，发现Fos-LI有节律地表达，Fos-LI在灯亮后不久升高，但在整个周期的其余时间内保持低水平。然而，这种节奏是光的直接后果，因为在持续的黑暗中，Fos-LI总是很低。这些结果的影响Fos在昼夜节律系统中可能的功能作用，并增加了我们对小鼠昼夜节律生理的光调节的理解。
In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus functions as the primary pacemaker of the circadian system. Light has been shown to induce Fos-like immunoreactivity (Fos-LI) in the SCN of rats and hamsters. The purpose of the present study was to evaluate extensively the effect of light on Fos-LI in the mouse SCN. Brief pulses of light administered to animals otherwise in constant darkness were found to induce Fos-LI. This photic induction was unaffected by the rd mutation, which causes the profound loss of photoreceptors but fails to affect circadian responses to light. Light regulation of Fos-LI was dependent upon the phase of the circadian cycle in which the light pulse was administered. Phases at which light causes phase shifts of the circadian system were permissive for Fos-LI induction (CT 16 and 24), while phases in which light does not cause phase shifts were not permissive (CT 6 and 9). The time course of the induction at CT 16 was also described. In a light/dark cycle, Fos-LI was found to be rhythmically expressed with Fos-LI elevated soon after the lights came on but remaining low throughout the rest of the cycle. However, this rhythm is a direct consequence of the light because in constant darkness Fos-LI was always low. These results have implications regarding the possible functional roles of Fos in the circadian system and add to our understanding of light regulation of circadian physiology in the mouse.