Nattie Eugene E, Li Aihua
Department of Physiology, Dartmouth Medical School, Lebanon, New Hampshire 03756-0001, USA.
J Appl Physiol (1985). 2002 May;92(5):2119-30. doi: 10.1152/japplphysiol.01128.2001.
To evaluate the function of widely distributed central chemoreceptors during sleep and wakefulness in the rat, we focally stimulate single chemoreceptor sites during naturally occurring sleep-wake cycles by microdialysis of artificial cerebrospinal fluid equilibrated with 25% CO2. In retrotrapezoid nucleus, this increased ventilation (tidal volume) by 24% only in wakefulness (Li A, Randall M, and Nattie E. J Appl Physiol 87: 910-919, 1999). In caudal medullary raphé, it increased ventilation (frequency) by 15-20% only in sleep (Nattie EE and Li A. J Appl Physiol 90: 1247-1257, 2001). Here, in nucleus tractus solitarius (NTS), focal acidification significantly increased ventilation by 11% in sleep and 7% in wakefulness rostrally (n = 5) and by 16% in sleep and 28% in wakefulness caudally (n = 5). The sleep-wake cycle was unaltered. Dialysis with 5% CO2 had no effect. Dialysis with 50% CO2 caudally did not further stimulate ventilation but did disrupt sleep. Central chemoreceptors in the NTS affect breathing in both sleep and wakefulness. The threshold for arousal in caudal NTS is greater than that for the stimulation of breathing.
为评估大鼠睡眠和清醒期间广泛分布的中枢化学感受器的功能，我们在自然发生的睡眠 - 觉醒周期中，通过对与25%二氧化碳平衡的人工脑脊液进行微透析，局部刺激单个化学感受器位点。在延髓后梯形核中，这仅在清醒时使通气量（潮气量）增加了24%（李A、兰德尔M和纳蒂E。《应用生理学杂志》87: 910 - 919, 1999）。在延髓尾部中缝核，它仅在睡眠时使通气量（频率）增加了15 - 20%（纳蒂EE和李A。《应用生理学杂志》90: 1247 - 1257, 2001）。在此，在孤束核（NTS）中，局部酸化在睡眠时使通气量显著增加了11%，在清醒时使延髓嘴侧通气量增加了7%（n = 5），在睡眠时使延髓尾侧通气量增加了16%，在清醒时增加了28%（n = 5）。睡眠 - 觉醒周期未改变。用5%二氧化碳进行透析没有效果。在延髓尾侧用50%二氧化碳进行透析并未进一步刺激通气，但确实扰乱了睡眠。孤束核中的中枢化学感受器在睡眠和清醒时均影响呼吸。延髓尾侧孤束核引起觉醒的阈值高于刺激呼吸的阈值。
