Circadian (24-h) rhythms in the suprachiasmatic nucleus (SCN) are established in utero in rodents, but rhythmicity of peripheral circadian clocks appears later in postnatal development. Since peripheral oscillators can be influenced by maternal feeding and behavior, we investigated whether exposure to the adverse environmental conditions of limited bedding (LB) during postnatal life would alter rhythmicity in the SCN, adrenal gland and liver in neonatal (postnatal day PND10), juvenile (PND28) and adult rats. We also examined locomotor activity in adults. Limited bedding increased nursing time and slightly increased fragmentation of maternal behavior. Exposure to LB reduced the amplitude of Per2 in the SCN on PND10. Adrenal clock gene expression (Bmal1, Per2, Cry1, Rev-erbα, Dbp) and corticosterone secretion were rhythmic at all ages in NB offspring, whereas rhythmicity of Bmal1, Cry1 and corticosterone was abolished in neonatal LB pups. Circadian gene expression in the adrenal and liver was well established by PND28. In adults, liver expression of several circadian genes was increased at specific daytimes by LB and the microstructure of locomotor behavior was altered. Thus, changes in maternal care and behavior might provide important signals to the maturing peripheral oscillators and modify, in particular their output functions in the long-term.

啮齿动物的视交叉上核 (SCN) 的昼夜节律 (24 小时) 是在子宫内建立的，但外周生物钟的节律在出生后发育中较晚出现。由于外周振荡器可能受到母亲喂养和行为的影响，我们研究了出生后生活中暴露于有限床上用品（LB）的不利环境条件是否会改变新生儿（出生后PND10）、青少年的SCN、肾上腺和肝脏的节律性。 （PND28）和成年大鼠。我们还检查了成人的运动活动。有限的床上用品增加了哺乳时间，并略微增加了产妇行为的碎片化。暴露于 LB 会降低 PND10 上 SCN 中Per2的振幅。 NB 后代的肾上腺时钟基因表达（ Bmal1 、 Per2、Cry1、Rev-erbα、Dbp）和皮质酮分泌在所有年龄段都有节律性，而Bmal1、Cry1和皮质酮的节律性在新生 LB 幼崽中被消除。 PND28 很好地建立了肾上腺和肝脏中的昼夜节律基因表达。在成人中，LB在特定的白天增加了一些昼夜节律基因的肝脏表达，并且运动行为的微观结构发生了改变。因此，产妇护理和行为的变化可能会向成熟的外周振荡器提供重要信号并进行修改，特别是从长远来看它们的输出功能。