Effects of nursing mothers on rPer1 and rPer2 circadian expressions in the neonatal rat suprachiasmatic nuclei vary with developmental stage
Effects of nursing mothers on rPer1 and rPer2 circadian expressions in the neonatal rat suprachiasmatic nuclei vary with developmental stage
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DOI：
10.1046/j.1460-9568.2002.02016.x
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发表时间：
2002-06-01
影响因子：
3.4
通讯作者：
Honma, K
中科院分区：
文献类型：
--
作者：
Ohta, H;Honma, S;Honma, K
通过测定大鼠视交叉上核（SCN）中Per 1（rPer 1）和rPer 2的表达水平，检查哺乳母亲携带大鼠幼崽的昼夜节律起搏器的能力。出生后立即将来自处于光暗周期（LD）下的母亲的新生大鼠盲化，并由寄养母亲在LD（LD盲幼仔）或反向光暗周期（DL; DL盲幼仔）下饲养。在出生后第6天（P），观察到小但显着的相位差异的SCN的昼夜节律基因表达的节奏不仅之间的盲目和有视力的小狗，而且两组之间的盲目的小狗，表明参与自由运行和母亲的影响，相位重置的昼夜节律的盲目的小狗。然而，从P6到P13，LD和DL盲幼仔的昼夜节律显示出相似程度的相位延迟，这表明哺乳母亲的影响消失了。从P13到P20（断奶当天），rPer 1和rPer 2节律以不同的方式相移，rPer 2节律与行为节律的关系比rPer 1更密切。这一发现表明，母亲在生命的第三周对rPer 1和rPer 2节律有不同的影响。得出结论，哺乳母亲的能力，夹带幼犬昼夜节律振荡取决于发展阶段。
The ability of nursing mothers to entrain the circadian pacemaker of rat pups was examined by measuring the rat Per1 (rPer1 ) and rPer2 expression levels in the suprachiasmatic nuclei (SCN). Newborn rats from mothers under a light-dark cycle (LD) were blinded immediately after birth and reared by foster mothers under either LD (LD blind pups) or reversed light-dark cycle (DL; DL blind pups). At postnatal day (P)6, small but significant phase differences were observed in the circadian gene expression rhythms of the SCN not only between the blind and sighted pups, but also between the two groups of blind pups, indicating the involvement of both free-running and maternal influence in phase-resetting the circadian rhythms of blind pups. However, from P6 to P13 the circadian rhythms of both LD and DL blind pups showed phase delays of similar extent, which suggests that the influence of nursing mothers was lost. From P13 to P20 (the day of weaning), the rPer1 and rPer2 rhythms phase-shifted in a different manner, the rPer2 rhythm being related more closely to the behavioural rhythm than was the rPer1 . This finding suggests a differential influence of mothers on the rPer1 and rPer2 rhythms in the third week of life. It is concluded that the ability of nursing mothers to entrain pup circadian oscillation depends on the developmental stage.