Neural mechanisms which induce blood pressure fluctuation during REM sleep

在快速眼动睡眠期间，体内平衡系统不能正常工作，自主神经系统出现较大波动。对于这种波动是如何产生的机制以及这种波动的生理意义，人们知之甚少。本研究通过实验研究下丘脑与脑干在快速眼动睡眠期间调节血压波动的关系，得到以下结果：1。通过碳纤维电极每隔200 ~ 400 μm电刺激一次氨基甲酸乙酯麻醉大鼠下丘脑。刺激外侧下丘脑（LHA）及其周围后可引起血压升高，而在该有效区域后可引起血压下降。记录未麻醉的头部受限大鼠的神经元活动与血压同时升高。部分LHA神经元与快速眼动睡眠期间血压升高密切相关。去年，我们发现在快速眼动睡眠期间，侧背被盖核（LDT）的胆碱能神经元与血压升高相关。所以，今年，我们同时对LHA和LDT进行了记录，发现当快速眼动睡眠期间血压升高时，LDT神经元的活动先于LHA神经元。这些结果表明，对于REM睡眠期间的血压波动，从LDT到LHA的兴奋性输入起着至关重要的作用。

During REM sleep, the homeostasis system does not show normal performance and large fluctuations of autonomic nervous systems appear. Little is known on the mechanisms how this fluctuation is generated and on the physiological significance of this fluctuation. In this study, the experiments were performed to elucidate the relationship of the hypothalamus and the brainstem for the regulation of blood pressure fluctuation during REM sleep, and we got the following results ;1. The hypothalamus of urethane anesthetized rats was electrically stimulated every 200-400 μm through a carbon fiber electrode which was moved by oil-pressure manipulator. Blood pressure increase was induced after the stimulation to the lateral hypothalamus (LHA) and its surroundings, while posterior to this effective area, blood pressure decrease was induced.2. Neuronal activity was recorded from unanesthetized head-restrained rats simultaneously with blood pressure. Some of the LHA neurons show close correlation with blood pressure increase during REM sleep.3.Last year, we found that the cholinergic neurons in the laterodorsal tegmental nucleus (LDT) showed the correlation with blood pressure increase during REM sleep. So, this year, we performed simultaneous recording from the LHA and LDT and found that when the blood pressure increase during REM sleep, the activity of the LDT neurons preceded that of the LHA neurons.These results suggest that for blood pressure fluctuation during REM sleep, the excitatory input from the LDT to the LHA have a crucial role.