Transplantation of fetal suprachiasmatic nuclei into middle-aged rats restores diurnal Fos expression in host.
Transplantation of fetal suprachiasmatic nuclei into middle-aged rats restores diurnal Fos expression in host.
复制标题
将胎儿视交叉上核移植到中年大鼠体内可恢复宿主体内的昼夜 Fos 表达。
DOI：
10.1152/ajpregu.1997.272.1.r422
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Wise,PM
中科院分区：
文献类型：
--
作者：
Cai,A;Lehman,MN;Lloyd,JM;Wise,PM
在幼年动物中，下丘脑的视交叉上核(SCN)是重要的昼夜节律起搏器，在Fos的表达中表现出光诱导的昼夜节律。这种即刻早期基因的表达已被用作SCN活动及其对外部线索(如光)做出反应的能力的指标。在目前的研究中，我们表明，当大鼠达到中年基线时，Fos的表达在黑暗中过早增加，而光诱导的Fos表达被钝化和延迟。我们还证明，将含有SCN的胎儿组织移植到中年大鼠的第三脑室，能够使老年宿主恢复表现出与年轻动物惊人相似的Fos表达的昼夜模式的能力。我们的发现得出以下结论：1)SCN细胞的昼夜活动模式在中年大鼠被钝化，2)SCN移植提供了独特的信号，使宿主的细胞系统能够恢复节律功能。这些结果为宿主在移植引起的功能恢复中所起的关键积极作用提供了新的见解。
In young animals, the suprachiasmatic nuclei (SCN) of the hypothalamus, which are critical circadian pacemakers, exhibit a light-induced diurnal rhythm in Fos expression. The expression of this immediate-early gene has been used as an index of the activity of the SCN and their ability to respond to external cues that entrain them, such as light. In the present study, we show that by the time rats reach middle age baseline Fos expression increases prematurely during the dark and that light-induced Fos expression is blunted and delayed. We also demonstrate that transplantation of fetal tissue containing the SCN into the third cerebral ventricle of middle-aged rats enables aged hosts to regain the ability to exhibit diurnal patterns of Fos expression that are strikingly similar to those observed in young animals. Our findings lead to the following conclusions: 1) the diurnal pattern of activity of SCN cells is blunted in middle-aged rats, and 2) SCN transplants provide unique signals that enable the cellular systems of the host to regain rhythmic functional capabilities. These results provide new insights into the critical active role that the host plays in restoration of function evoked by the presence of a transplant.