Cold exposure impairs dark-pulse capacity to induce REM sleep in the albino rat
Cold exposure impairs dark-pulse capacity to induce REM sleep in the albino rat
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DOI：
10.1111/j.1365-2869.2008.00658.x
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发表时间：
2008-06-01
影响因子：
4.4
通讯作者：
Amici, Roberto
中科院分区：
文献类型：
--
作者：
Baracchi, Francesca;Zamboni, Giovanni;Amici, Roberto
在白化大鼠的非快速眼动睡眠（NREMS）中，当灯突然关闭（暗脉冲，DP）时，可以以高概率和短潜伏期诱导快速眼动睡眠（REMS）的开始。本研究的目的是研究DP在多大程度上可以克服暴露于低环境温度（Ta）时抑制REMS发生的综合体温调节机制。为此，通过分析大鼠不同时段的脑电图、心电图、下丘脑温度和运动活动，研究了在12小时：12小时明暗循环的前6小时光照期非节律性重复DP（每次3分钟）诱导REMS的效率。结果表明，DP释放触发了从NREMS到REMS的转变，与自发发生的转变相当。然而，在冷暴露期间，DP诱导REMS的效率降低，其程度与自发REMS发生时的效果相当。这种损伤与传递dp时的低Delta活动和高交感神经张力有关。在分娩期间，重复使用DP增加了REMS量，随后观察到REMS负反弹。综上所述，DP并没有克服在寒冷条件下抑制REMS的综合热调节机制。这些结果强调了热调节激活和REMS发生相互排斥的重要生理意义，并支持了体温中枢控制的暂停是REMS发生的先决条件的假设。
In the albino rat, a REM sleep (REMS) onset can be induced with a high probability and a short latency when the light is suddenly turned off (dark pulse, DP) during non-REM sleep (NREMS). The aim of this study was to investigate to what extent DP delivery could overcome the integrative thermoregulatory mechanisms that depress REMS occurrence during exposure to low ambient temperature (Ta). To this aim, the efficiency of a non-rhythmical repetitive DP (3 min each) delivery during the first 6-h light period of a 12 h : 12 h light-dark cycle in inducing REMS was studied in the rat, through the analysis of electroencephalogram, electrocardiogram, hypothalamic temperature and motor activity at different Tas. The results showed that DP delivery triggers a transition from NREMS to REMS comparable to that which occurs spontaneously. However, the efficiency of DP delivery in inducing REMS was reduced during cold exposure to an extent comparable with that observed in spontaneous REMS occurrence. Such impairment was associated with low Delta activity and high sympathetic tone when DPs were delivered. Repetitive DP administration increased REMS amount during the delivery period and a subsequent negative REMS rebound was observed. In conclusion, DP delivery did not overcome the integrative thermoregulatory mechanisms that depress REMS in the cold. These results underline the crucial physiological meaning of the mutual exclusion of thermoregulatory activation and REMS occurrence, and support the hypothesis that the suspension of the central control of body temperature is a prerequisite for REMS occurrence.