Light and GABA)(A) receptor activation alter period mRNA levels in the SCN of diurnal Nile grass rats.
Light and GABA)(A) receptor activation alter period mRNA levels in the SCN of diurnal Nile grass rats.
复制标题
光和 GABA)(A) 受体激活改变昼夜尼罗草大鼠 SCN 中的周期 mRNA 水平。
DOI：
10.1111/j.1460-9568.2006.05166.x
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Albers,HElliott
中科院分区：
文献类型：
--
作者：
Novak,ColleenM;Ehlen,JChristopher;Paul,KetemaN;Fukuhara,Chiaki;Albers,HElliott
We examinedPeriod(Per) mRNA rhythms in the suprachiasmatic nucleus (SCN) of a diurnal rodent and assessed how phase‐shifting stimuli acutely affect SCNPermRNA using semiquantitativein situhybridization. First,Per1andPer2varied rhythmically in the SCN over the course of one circadian cycle in constant darkness:Per1mRNA was highest in the early to mid‐subjective day, whilePer2mRNA levels peaked in the late subjective day. Second, acute light exposure in the early subjective night significantly increased bothPer1andPer2mRNA. Third,Per2but notPer1levels decreased 1 and 2 h after injection of the γ‐aminobutyric acid (GABA)Areceptor agonist muscimol into the SCN during the subjective day. Fourth, muscimol also reduced the light‐inducedPer2in the early subjective night, butPer1induction by light was not significantly affected. Consistent with previous studies, these data demonstrate that diurnal and nocturnal animals show very similar daily patterns ofPermRNA and light‐inducedPerincreases in the SCN. As with light, muscimol alters circadian phase, and daytime phase alterations induced by muscimol are associated with significant decreases inPer2mRNA. In diurnal animals, muscimol‐induced decreases inPerare associated with phase delays rather than advances. The direction of the daytime phase shift may be determined by the relative suppression ofPer1vs.Per2in SCN cells. As in nocturnal animals, changes inPer1andPer2mRNA by photic and non‐photic stimuli appear to be associated with circadian phase alteration.
