猫后根初级传入纤维终未在后索核内的超微结构及其突触联系

FINE STRUCTURE AND SYNAPTIC RELATIONSHIP OF DORSAL ROOT AFFERENT TERMINALS IN DORSAL COLUMN NUCLEUS OF CAT

用顺行溃变方法对猫后索核内后根初级传入纤维终末的超微结构和突触联系进行了研究.在切断C4～T1和 L4～S1脊神经后根3～4天后,电镜下发现后索核内有三种溃变终末,出现最多的是电子致密型溃变,此外,也观察到了少量的神经微丝型溃变和电子透明型溃变.溃变的初级传入终末多数较大,含有圆形突触小泡.溃变初级传入终末作为突触前成分主要与后索核内的树突形成轴-树突触,而轴-体突触和轴-轴突触较少.此外,还观察到溃变轴突终末参与形成突触复合体.

The anterograde degeneration and electron microscopic technique were employed to investigate the primary afferent terminals in the dorsal column nucleus (DCN) of the cat. 3 ~ 4 days after sections at the C4~ T1 or L4~S1 dorsal roots of 12 cats three types of degenerating afferent terminals could be identified. The eletron-dense degeneration was the most common while the neurofilamentous and electron-lucent degenerations were less encountered. The primary afferent terminals in the DCN were mostly large and contained round vesicles. They were mainly presynaptic to dendrites and also formed axo-somatic and axo-axo synapses. In addition, they participated in the formation of synaptic complexes.