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激活蓝斑在孤束核水平对迷走神经传入的抑制

陈永跃, 黄仲荪

重庆医科大学生理学教研室.重庆 630046

摘要

在戊巴比妥钠麻醉兔,电刺激颈迷走神经中枢端,在同侧孤束核(NTS)区可记录到一个由三个子波组成的复合电位。它们的潜伏期分别为6.8±0.6 ms(P1),25.8±4.2 ms(P2)和89.1±2.7 ms(P3)。这可能代表着不同性质的迷走传入纤维的突触后电位。同侧蓝斑(LC)内微量注射谷氨酸钠使P2,P3波的幅值明显降低。电刺激LC在同侧NTS区诱发出111个有反应单位,其潜伏期平均为6.3±1.4 ms。在169个对迷走传入刺激有反应的NTS单位中,有90个对LC刺激也有反应。39个(占43.3%)会聚性单位对上述两种刺激的反应相似,而其余的呈不同的反应。对LC和迷走刺激分别均呈兴奋反应的25个NTS单位中,如预先刺激LC,则有14个单位对迷走刺激的兴奋反应受到明显抑制, 另11个单位的兴奋反应完全被抑制。上述结果提示:激活蓝斑核具抑制NTS对迷走传入刺激反应的作用。

关键词： 蓝斑; 孤束核; 自主神经系统; 脑干; 诱发电位; 兔

Activation of locus coeruleus inhibits vagal inputs in nucleus tractus solitarius

Chen Yongyue, Huang Zhongsun

Department of Physiology, Chongqing University of Medical Sciences. Chongqing 630046

Abstract

On pentobarbital anesthetized rabbits, a three-wavelet compound potential to cervical vagal afferent stimulation was recorded in ipsilateral nucleus tractus solitarius (NTS).The latency of the three wavelets (P1,P2 and P3) was 6.8±0.6 ms (P1), 25.8±4.2 ms (P2) and 89.1±2.7 ms (P3) respectively,which might represent postsynaptic activity of different kinds of vagal afferent fibers.Microinjection of glutamate into ipsilateral locus coeruleus (LC) decreased the amplitude of P2 and P3 significantly. Electrical stimulation of LC could activate 111 units in ipsilateral NTS with a mean latency of 6.3±1.4 ms. Of the 169 units in the NTS to vagal afferent stimulation, 90 units also responded to LC stimulation. 39 (43.3%) of the theninety, units shows similar response to both stimuli, while the rest show different response. Of the 25 units which showed excitatory response to both LC and vagal stimulation, but when LC stimulation was followed by vagus stimulation, the latter^s response was either markedly suppressed (14 units) or completely inhibited (11 units). These results showed that activation of LC exerts an inhibitory effect on the responses of the NTS to vagal afferent stimulation.

Key words: Locus coeruleus;Nucleus tractus solitarius;Autonomic nerve system;Brainstem;Evoked potential;Rabbit

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引用本文：

陈永跃, 黄仲荪. 激活蓝斑在孤束核水平对迷走神经传入的抑制[J]. 生理学报 1997; 49 (1): .

Chen Yongyue, Huang Zhongsun. Activation of locus coeruleus inhibits vagal inputs in nucleus tractus solitarius. Acta Physiol Sin 1997; 49 (1): (in Chinese with English abstract).