Buijs Ruud M, la Fleur Susanne E, Wortel Joke, Van Heyningen Caroline, Zuiddam Laura, Mettenleiter Thomas C, Kalsbeek Andries, Nagai Katsuya, Niijima Akira
Netherlands Institute for Brain Research, 1105 AZ Amsterdam, The Netherlands.
J Comp Neurol. 2003 Sep 8;464(1):36-48. doi: 10.1002/cne.10765.
Opposing parasympathetic and sympathetic signals determine the autonomic output of the brain to the body and the change in balance over the sleep-wake cycle. The suprachiasmatic nucleus (SCN) organizes the activity/inactivity cycle and the behaviors that go along with it, but it is unclear how the hypothalamus, in particular the SCN, with its high daytime electrical activity, influences this differentiated autonomic balance. In a first series of experiments, we visualized hypothalamic pre-sympathetic neurons by injecting the retrograde tracer Fluoro-Gold into the thoracic sympathetic nuclei of the spinal cord. Pre-parasympathetic neurons were revealed by injection of the retrograde trans-synaptic tracer pseudorabies virus (PRV) into the liver and by sympathetic liver denervation, forcing the virus to infect via the vagus nerve only. This approach revealed separate pre-sympathetic and pre-parasympathetic neurons in the brainstem and hypothalamus. Next, selective retrograde tracing with two unique reporter PRV strains, one injected into the adrenal and the other into the sympathetic denervated liver, demonstrated that there are two separate populations of pre-sympathetic and pre-parasympathetic neurons within the paraventricular nucleus of the hypothalamus. Interestingly, this segregation persists into the SCN, where, as a result, the day-night balance in autonomic function of the organs is affected by specialized pre-sympathetic or pre-parasympathetic SCN neurons. These separate preautonomic SCN neurons provide the anatomical basis for the circadian-driven regulation of the parasympathetic and sympathetic autonomic output.
相互对立的副交感神经和交感神经信号决定了大脑对身体的自主输出以及睡眠-觉醒周期中平衡的变化。视交叉上核（SCN）组织活动/不活动周期及其伴随的行为，但尚不清楚下丘脑，特别是具有高日间电活动的SCN如何影响这种差异化的自主平衡。在第一系列实验中，我们通过将逆行示踪剂荧光金注射到脊髓的胸段交感神经核中来可视化下丘脑的交感神经节前神经元。通过将逆行跨突触示踪剂伪狂犬病病毒（PRV）注射到肝脏中以及通过交感神经肝去神经支配，迫使病毒仅通过迷走神经感染，从而揭示了副交感神经节前神经元。这种方法揭示了脑干和下丘脑中单独的交感神经节前和副交感神经节前神经元。接下来，用两种独特的报告PRV毒株进行选择性逆行追踪，一种注射到肾上腺，另一种注射到交感神经去神经支配的肝脏，结果表明在下丘脑室旁核内有两个独立的交感神经节前和副交感神经节前神经元群体。有趣的是，这种分离一直持续到SCN，结果，器官自主功能的昼夜平衡受到专门的交感神经节前或副交感神经节前SCN神经元的影响。这些独立的自主神经SCN神经元为昼夜驱动的副交感神经和交感神经自主输出调节提供了解剖学基础。
