Chen Y Y, Huang Z S
Department of Physiology, Chongqing University of Medical Sciences.
Sheng Li Xue Bao. 1997 Feb;49(1):39-44.
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 ninety, 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.
在戊巴比妥麻醉的家兔身上，记录了同侧孤束核（NTS）对颈迷走神经传入刺激的三小波复合电位。这三个小波（P1、P2和P3）的潜伏期分别为6.8±0.6毫秒（P1）、25.8±4.2毫秒（P2）和89.1±2.7毫秒（P3），这可能代表了不同类型迷走神经传入纤维的突触后活动。向同侧蓝斑（LC）微量注射谷氨酸可显著降低P2和P3的幅度。电刺激LC可激活同侧NTS中的111个单位，平均潜伏期为6.3±1.4毫秒。在NTS中，对迷走神经传入刺激有反应的169个单位中，有90个单位也对LC刺激有反应。这90个单位中的39个（43.3%）对两种刺激表现出相似的反应，而其余单位表现出不同的反应。在对LC和迷走神经刺激均表现出兴奋反应的25个单位中，当先进行LC刺激再进行迷走神经刺激时，后者的反应要么明显受到抑制（14个单位），要么完全被抑制（11个单位）。这些结果表明，LC的激活对NTS对迷走神经传入刺激的反应具有抑制作用。
