DEFINITION OF THE DEVELOPMENTAL TRANSITION FROM DOPAMINERGIC TO PHOTIC REGULATION OF C-FOS GENE-EXPRESSION IN THE RAT SUPRACHIASMATIC NUCLEUS
DEFINITION OF THE DEVELOPMENTAL TRANSITION FROM DOPAMINERGIC TO PHOTIC REGULATION OF C-FOS GENE-EXPRESSION IN THE RAT SUPRACHIASMATIC NUCLEUS
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DOI：
10.1016/0169-328x(95)00117-b
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发表时间：
1995-10-01
期刊：
影响因子：
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通讯作者：
REPPERT, SM
中科院分区：
文献类型：
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作者：
WEAVER, DR;REPPERT, SM
D-1-多巴胺受体刺激诱导c-fos基因表达在胎儿视交叉上核（SCN），但不是在成年大鼠SCN。夜间光照诱导成年人SCN中c-fos基因表达。本实验的目的是确定从多巴胺和光调控的c-fos基因表达的SCN的发育过渡。用D-1-多巴胺受体激动剂SKF 38393（10 mg/kg）治疗可增加出生后第0天（PD）和第1天白天和夜间以及PD 2夜间SCN c-fos基因表达，但PD 4时c-fos反应消失。光诱导c-fos基因表达是明显的，在白天和夜间在每个年龄检查，从PD 0到PD 6。白天光照后c-fos表达的幅度和分布与PD 2开始的夜间光照反应不同，表明生物钟调节（门控）PD 2的c-fos反应。眼眶摘除术阻止了PD 2夜间光诱导c-fos，表明视网膜介导。视网膜下丘脑束的到来并不会导致对SKF的c-fos反应的发育丧失; PD 0时摘除眼球的动物在PD 6时对SKF不敏感，视觉上完整的对照组也是如此。结果表明，多巴胺能和光输入可以调节SCN c-fos基因表达的早期在新生儿期，和SKF的敏感性的发育损失是不是由于光输入的SCN的到来。从多巴胺能到光调控c-fos基因表达的发育转变大致平行于从母体到光诱导发育生物钟的发育转变。
D-1-dopamine receptor stimulation induces c-fos gene expression in the fetal suprachiasmatic nucleus (SCN), but not in the adult rat SCN. Light exposure at night induces c-fos gene expression in the adult SCN. The present experiments were designed to define the developmental transition from dopaminergic to photic regulation of c-fos gene expression in the SCN. Treatment with the D-1-dopamine receptor agonist SKF 38393 (10 mg/kg) increased SCN c-fos gene expression during both day and night on postnatal day (PD) 0, 1, and at night on PD 2, but the c-fos response disappeared by PD 4. Photic induction of c-fos gene expression was apparent during both day and night at each age examined, from PD 0 through PD 6. The magnitude and distribution of c-fos expression following light during the daytime was distinguishable from the response to light at night beginning on PD 2, indicating that the circadian clock regulates (gates) the c-fos response by PD 2. Orbital enucleation prevents the induction of c-fos by light at night on PD 2, indicating retinal mediation. Developmental loss of the c-fos response to SKF is not precipitated by the arrival of the retinohypothalamic tract; animals enucleated on PD 0 were insensitive to SKF on PD 6, as were visually intact controls. The results demonstrate that both dopaminergic and photic inputs can regulate SCN c-fos gene expression early in the neonatal period, and that the developmental loss of sensitivity to SKF is not due to the arrival of photic input to the SCN. The developmental transition from dopaminergic to photic regulation of c-fos gene expression roughly parallels the developmental transition from maternal to photic entrainment of the developing biological clock.