大鼠孤束核向伏核投射的神经元接受迷走神经的初级传入——溃变与HRP追踪结合法的电镜观察

本文用切断一侧结状神经节近侧端的迷走神经和HRP注入伏核逆行追踪相结合的方法,在电镜水平对孤束核向伏核投射的神经元是否接受迷走神经初级传入纤维终末进行了研究。在孤束核内可见下列突触关系:(1)溃变轴突终末与HRP逆标树突形成轴-树突触;(2)无标记正常轴突终末与HRP逆标胞体或树突分别形成轴-体或轴-树突触;(3)HRP顺标轴突终末与无标记树突形成轴-树突触;(4)溃变轴突终末与无标记树突形成轴-树突触。由上述结果可知:孤束核向伏核投射的神经元接受迷走神经的初级传入终末;伏核神经元的下行终末与孤束核内的神经元之间有突触联系。

VAGAL INNERVATION OF NEURONS IN THE NUCLEUS TRACTUSSOLITARII PROJECTING TO THE NUCLEUS ACCUMBENS IN THE RAT: AN HRP TRACING COMBINED WITH DEGENERATION STUDY BY ELECTRON MICROSCOPY

Horseradish peroxidase(HRP)was injected into the right side of the nucleus accumbens(Acb)and the vagal afferents were allowed to degenerate after resection of the right nodose ganglion. The relationship between the HRP labelled structures and the degenerated axonal terminals in the nucleus tractus solitarii(NTS)were examined by electron microscopy. The degenerated axonal terminals in the right NTS were often found to make synaptic contacts with the HRP retrogradely labelled dendrites. The anterogradely labelled axonal terminals in turn were found to make synaptic contacts with unlabelled dendrites. These findings suggest that(1)some of the NTS neurons projecting to the Ach receive the vagal innervation arid(2)there are direct connections between the NTS neurons and the Acb descending terminals.