The development of day-night differences in sleep and wakefulness in Norway rats and the effect of bilateral enucleation
The development of day-night differences in sleep and wakefulness in Norway rats and the effect of bilateral enucleation
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DOI：
10.1177/0748730408316954
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发表时间：
2008-06-01
影响因子：
3.5
通讯作者：
Blumberg, Mark S.
中科院分区：
文献类型：
--
作者：
Gall, Andrew J.;Todd, William D.;Blumberg, Mark S.
视交叉上核表现出昼夜节律性在胎儿和婴儿大鼠，但鲜为人知的是，这种节律性的后果，婴儿的行为。在这里，在实验1中，作者测量了出生后第2天（P）、第8天、第15天和第21天受试者的白天和夜间的睡眠和觉醒。早在P2，睡眠-觉醒活动的昼夜差异被检测到。夜间觉醒在P15左右开始出现，并由P21可靠地表达。作者假设，出生后第一周的光夹带过程取决于视网膜下丘脑束（RHT）和SCN之间连接的发展，影响了夜间觉醒的后期出现。为了验证这一假设，在实验2中，在P3和P11，即光夹带之前和之后，将幼鼠双侧去核。而在P11去核并在P21检测的幼仔表现出夜间觉醒增加，与假手术对照相同，在P3去核并在P21检测的幼仔表现出相反的白天觉醒增加模式。在P28和P35测试的幼崽表现出相同的白天觉醒增加的模式。总之，这些结果表明，产前和产后的经验调制物种典型的昼夜睡眠-觉醒模式的发展。此外，作者认为，视觉系统的刺激，通过RHT的连接与SCN，施加组织的影响，发展昼夜节律系统，因此，有助于出现在这个物种的非对称性。
The suprachiasmatic nucleus exhibits circadian rhythmicity in fetal and infant rats, but little is known about the consequences of this rhythmicity for infant behavior. Here, in experiment 1, the authors measured sleep and wakefulness in rats during the day and night in postnatal day (P)2, P8, P15, and P21 subjects. As early as P2, day-night differences in sleep-wake activity were detected. Nocturnal wakefulness began to emerge around P15 and was reliably expressed by P21. The authors hypothesized that the process of photic entrainment over the 1st postnatal week, which depends on the development of connectivity between the retinohypothalamic tract (RHT) and the SCN, influences the later emergence of nocturnal wakefulness. To test this hypothesis, in experiment 2 infant rats were enucleated bilaterally at P3 and P11, that is, before and after photic entrainment. Whereas pups enucleated at P11 and tested at P21 exhibited increased wakefulness at night, identical to sham controls, pups enucleated at P3 and tested at P21 exhibited the opposite pattern of increased wakefulness during the day. Pups tested at P28 and P35 exhibited this same pattern of increased daytime wakefulness. All together, these results suggest that prenatal and postnatal experience modulates the development of species-typical circadian sleep-wake patterns. Moreover, the authors suggest that visual system stimulation, via the RHT's connections with the SCN, exerts an organizational influence on the developing circadian system and, consequently, contributes to the emergence of nocturnality in this species.