Barber W D, Yuan C S
Department of Anatomy, University of Arizona Health Sciences Center, Tucson 85724.
Am J Physiol. 1989 Jul;257(1 Pt 1):G24-9. doi: 10.1152/ajpgi.1989.257.1.G24.
The brain stem neuronal responses to electrical stimulation of gastric branches of the ventral vagal trunk serving the proximal stomach were localized and evaluated in anesthetized cats. The responses were equally distributed bilaterally in the region of nucleus solitarius in the caudal brain stem. The mean latency of the response was 289 +/- 46 (SD) ms, which translated into a conduction velocity of less than 1 m/s based on the distance between the stimulating and recording electrodes. The responses consisted of single and multiple spikes that showed slight variability in the latency, indicating orthodromic activation via a synapse in approximately 98% of the responses recorded. Forty two percent of the units tested showed evidence of convergence of input from vagal afferent fibers in different branches of the ventral vagal trunk that served the proximal stomach. The resultant activity pattern of the unitary response appeared to be the product of 1) the gastric sensory input or modality conveyed by the afferent source and 2) the time of arrival and diversity of modalities served by other gastric afferents impinging on the unit. This provides a mechanism capable of responding on the basis of specific sensory modalities that dynamically reflect ongoing events monitored and conveyed by other gastric afferents in the region.
在麻醉猫中，对支配胃近端的迷走神经干腹侧支的胃分支进行电刺激，定位并评估脑干神经元的反应。这些反应在延髓尾部孤束核区域双侧均等分布。反应的平均潜伏期为289±46（标准差）毫秒，根据刺激电极与记录电极之间的距离，这意味着传导速度小于1米/秒。反应由单个和多个尖峰组成，潜伏期略有变化，表明在记录的约98%的反应中是通过突触进行顺向激活。42%的测试单位显示有来自支配胃近端的迷走神经干不同分支的迷走传入纤维输入汇聚的证据。单一反应的最终活动模式似乎是1）传入源所传递的胃感觉输入或模式与2）其他作用于该单位的胃传入纤维所服务的模式的到达时间和多样性共同作用的结果。这提供了一种能够基于特定感觉模式做出反应的机制，这些模式动态反映了该区域其他胃传入纤维所监测和传递的正在进行的事件。
