Department of Molecular & Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
PLoS One. 2013 Aug 12;8(8):e70481. doi: 10.1371/journal.pone.0070481. eCollection 2013.
Sleep-wake cycling is controlled by the complex interplay between two brain systems, one which controls vigilance state, regulating the transition between sleep and wake, and the other circadian, which communicates time-of-day. Together, they align sleep appropriately with energetic need and the day-night cycle. Neural circuits connect brain stem sites that regulate vigilance state with the suprachiasmatic nucleus (SCN), the master circadian clock, but the function of these connections has been unknown. Coupling discrete stimulation of pontine nuclei controlling vigilance state with analytical chemical measurements of intra-SCN microdialysates in mouse, we found significant neurotransmitter release at the SCN and, concomitantly, resetting of behavioral circadian rhythms. Depending upon stimulus conditions and time-of-day, SCN acetylcholine and/or glutamate levels were augmented and generated shifts of behavioral rhythms. These results establish modes of neurochemical communication from brain regions controlling vigilance state to the central circadian clock, with behavioral consequences. They suggest a basis for dynamic integration across brain systems that regulate vigilance states, and a potential vulnerability to altered communication in sleep disorders.
睡眠-觉醒周期受两个大脑系统的复杂相互作用控制，一个系统控制警觉状态，调节睡眠和觉醒之间的转换，另一个系统是昼夜节律，它传达一天中的时间。它们共同使睡眠与能量需求和昼夜节律相适应。神经回路将调节警觉状态的脑干位点与视交叉上核（SCN）连接起来，SCN 是主生物钟，但这些连接的功能尚不清楚。我们通过对控制警觉状态的脑桥核进行离散刺激，并对小鼠 SCN 内微透析物进行分析化学测量，发现 SCN 中有显著的神经递质释放，同时行为性昼夜节律也被重置。根据刺激条件和一天中的时间，SCN 乙酰胆碱和/或谷氨酸水平增加，并产生行为节律的转移。这些结果确立了从控制警觉状态的脑区到中央生物钟的神经化学通讯模式，并具有行为后果。它们为调节警觉状态的大脑系统的动态整合提供了基础，并为睡眠障碍中通讯改变的潜在脆弱性提供了基础。
