Persistence of sleep-temperature coupling after suprachiasmatic nuclei lesions in rats
Persistence of sleep-temperature coupling after suprachiasmatic nuclei lesions in rats
复制标题
DOI：
10.1152/ajpregu.00093.2005
复制
发表时间：
2005-09-01
影响因子：
2.8
通讯作者：
McGinty, D
中科院分区：
文献类型：
--
作者：
Baker, FC;Angara, C;McGinty, D
视交叉上核（SCN）调节哺乳动物的体温（T-b）和警觉状态的昼夜节律。我们研究了 SCN 损伤后昼夜节律被取消的大鼠（SCNx 大鼠），以研究睡眠-觉醒状态的超昼夜节律与损伤后暴露的脑温度 (T-br) 之间的关联。 SCNx 大鼠的 T-br 超昼夜节律（平均周期：3.6 小时）与睡眠密切相关。在每个超电周期内，非快速眼动 (NREM) 睡眠在 T-br 峰值后 5 +/- 1 分钟开始，此后温度继续缓慢下降（0.02 +/- 0.006 摄氏度/分钟）直至达到最小值。睡眠和慢波活动（SWA）（睡眠强度指数）与温度下降有关。互相关分析显示，T-br 的节律早于 SWA 2-10 分钟。我们还研究了 SCNx 大鼠和对照大鼠在 24 小时内对温和环境冷却（18 摄氏度）和变暖（30 摄氏度）的体温调节和睡眠觉醒反应。 SCNx 大鼠和对照组对环境温度变化的反应相似。降温会减少快速眼动睡眠并增加觉醒时间。变暖会增加 T-br，减弱超电 T-br 节律的幅度，并增加过渡到 NREM 睡眠的次数。 SCNx 大鼠和对照组的 NREM 睡眠、REM 睡眠和清醒百分比相似，并且每 24 小时内的平均 T-b 也相同。我们的结果表明，在大鼠中，SCN 调节时间，但不调节睡眠量或睡眠-觉醒状态的稳态控制或环境温度偏差期间的 T-b。
The suprachiasmatic nucleus (SCN) regulates the circadian rhythms of body temperature (T-b) and vigilance states in mammals. We studied rats in which circadian rhythmicity was abolished after SCN lesions (SCNx rats) to investigate the association between the ultradian rhythms of sleep-wake states and brain temperature (T-br), which are exposed after lesions. Ultradian rhythms of T-br (mean period: 3.6 h) and sleep were closely associated in SCNx rats. Within each ultradian cycle, nonrapid eye movement (NREM) sleep was initiated 5 +/- 1 min after T-br peaks, after which temperature continued a slow decline (0.02 +/- 0.006 degrees C/min) until it reached a minimum. Sleep and slow wave activity (SWA), an index of sleep intensity, were associated with declining temperature. Cross-correlation analysis revealed that the rhythm of T-br preceded that of SWA by 2-10 min. We also investigated the thermoregulatory and sleep-wake responses of SCNx rats and controls to mild ambient cooling (18 degrees C) and warming (30 degrees C) over 24-h periods. SCNx rats and controls responded similarly to changes in ambient temperature. Cooling decreased REM sleep and increased wake. Warming increased T-br, blunted the amplitude of ultradian T-br rhythms, and increased the number of transitions into NREM sleep. SCNx rats and controls had similar percentages of NREM sleep, REM sleep, and wake, as well as the same average T-b within each 24-h period. Our results suggest that, in rats, the SCN modulates the timing but not the amount of sleep or the homeostatic control of sleep-wake states or T-b during deviations in ambient temperature.