Departments of Pharmacy, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, 230031, China.
Department of Physiology and Functional Experiment center, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.
BMC Neurosci. 2024 Jul 22;25(1):34. doi: 10.1186/s12868-024-00881-0.
The regulation of circadian rhythms and the sleep-wake states involves in multiple neural circuits. The suprachiasmatic nucleus (SCN) is a circadian pacemaker that controls the rhythmic oscillation of mammalian behaviors. The basal forebrain (BF) is a critical brain region of sleep-wake regulation, which is the downstream of the SCN. Retrograde tracing of cholera toxin subunit B showed a direct projection from the SCN to the horizontal limbs of diagonal band (HDB), a subregion of the BF. However, the underlying function of the SCN-HDB pathway remains poorly understood. Herein, activation of this pathway significantly increased non-rapid eye movement (NREM) sleep during the dark phase by using optogenetic recordings. Moreover, activation of this pathway significantly induced NREM sleep during the dark phase for first 4 h by using chemogenetic methods. Taken together, these findings reveal that the SCN-HDB pathway participates in NREM sleep regulation and provides direct evidence of a novel SCN-related pathway involved in sleep-wake states regulation.
昼夜节律和睡眠-觉醒状态的调节涉及多个神经回路。视交叉上核（SCN）是控制哺乳动物行为节律性振荡的昼夜节律起搏器。基底前脑（BF）是睡眠-觉醒调节的关键脑区，是 SCN 的下游。霍乱毒素亚单位 B 的逆行追踪显示，SCN 与 BF 的水平支对角带（HDB）之间存在直接投射。然而，SCN-HDB 通路的潜在功能仍知之甚少。在此，通过光遗传学记录发现，该通路的激活显著增加了暗期的非快速眼动（NREM）睡眠。此外，通过化学遗传方法发现，该通路的激活在暗期的前 4 小时显著诱导了 NREM 睡眠。总之，这些发现表明 SCN-HDB 通路参与了 NREM 睡眠的调节，并为参与睡眠-觉醒状态调节的新型 SCN 相关通路提供了直接证据。
