Opp M R, Toth L A
Department of Psychiatry & Behavioral Sciences, University of Texas Medical Branch, Galveston 77555, USA.
Life Sci. 1998;62(10):923-36. doi: 10.1016/s0024-3205(98)00010-1.
The vagus nerve appears to serve a role in mediating peripheral immunologic influences on CNS processes. Previous work demonstrates that subdiaphragmatic vagotomy prevents or attenuates many of the behavioral and physiological responses to exogenous interleukin-1 (IL-1) or lipopolysaccharide (LPS). We determined whether the somnogenic effects of IL-1 and LPS were altered in vagotomized rats, and whether the effects of vagotomy on IL-1- and LPS-induced alterations in sleep would vary as a function of circadian phase. The data indicate that vagotomy does not influence the normal circadian patterns of sleep and wakefulness in untreated rats, or modify the pyrogenic or somnogenic effects of intracerebroventricular administration of IL-1. However, in unchallenged animals vagotomy reduces basal brain temperatures, increases delta wave amplitudes during slow-wave sleep (SWS), and induces a reduced rate of weight gain, gastric distension, and adrenal hypoplasia. Vagotomy attenuates the febrile effects of IL-1 during both light and dark phases, attenuated IL-1-induced sleep enhancement during the dark phase, and attenuated IL-1-induced increases in delta wave amplitudes within SWS during the light period. In LPS-treated rats, vagotomy attenuates the febrile and SWS responses to LPS after administration at light onset, but not after administration at dark onset. These results indicate that subdiaphragmatic vagotomy attenuates several of the somnogenic and pyrogenic effects of IL-1beta and LPS, although the effectiveness of the vagal transection in modulating these responses is influenced by circadian factors.
迷走神经似乎在介导外周免疫对中枢神经系统过程的影响中发挥作用。先前的研究表明，膈下迷走神经切断术可预防或减弱对外源性白细胞介素-1（IL-1）或脂多糖（LPS）的许多行为和生理反应。我们确定了在迷走神经切断的大鼠中IL-1和LPS的促睡眠作用是否改变，以及迷走神经切断术对IL-1和LPS诱导的睡眠改变的影响是否会随昼夜节律阶段而变化。数据表明，迷走神经切断术不影响未处理大鼠正常的昼夜睡眠和觉醒模式，也不改变脑室内注射IL-1的致热或促睡眠作用。然而，在未受刺激的动物中，迷走神经切断术会降低基础脑温，增加慢波睡眠（SWS）期间的δ波振幅，并导致体重增加率降低、胃扩张和肾上腺发育不全。迷走神经切断术在光照期和黑暗期均减弱了IL-1的发热作用，在黑暗期减弱了IL-1诱导的睡眠增强作用，并在光照期减弱了IL-1诱导的SWS期间δ波振幅的增加。在LPS处理的大鼠中，迷走神经切断术减弱了在光照开始时给药后对LPS的发热和SWS反应，但在黑暗开始时给药后则没有减弱。这些结果表明，膈下迷走神经切断术减弱了IL-1β和LPS的几种促睡眠和致热作用，尽管迷走神经切断术调节这些反应的有效性受昼夜节律因素影响。
