与眶下神经相关的初级传入纤维终末的溃变、非突触部位胞吐及突触联系

切断眶下神经的各组大鼠存活2～30天后分别杀死,于其三叉神经尾侧脊束核胶状质亚核内观察了一级传入纤维轴突终末的溃变过程.非突触部位胞吐及突触联系.结果发现:(1)眶下神经的跨节溃变、以突触小泡聚集、融合、空泡形成为主要特征,无微丝增生现象:(2)部分溃变终末内的线粒体明显肿胀变暗.呈球形改变:(3)大致密核心小泡的溃变时间远滞后于突触小泡.两者并不同步进行;(4)轴突终未在溃变过程中,其内的大致密核心小泡仍然进行非突触部位胞吐;(5)溃变纤维终末于胶状质内分别形成轴一树、轴一体、轴一轴三种类型的突触、并参与了突触复合体的形成.

DEGENERATION,NONSYNAPTIC EXOCYTOSIS AND SYNAPTIC RELATIONS OF PRIMERAL AFFERENT FIBER TERMINALS OF INFRA ORBITAL NERVE

In this sutdy, we investigated the degenerate alteration, nonsynaptic exocytosis and synaptic relations of primary afferent fiber terminals in the substantia gelitinosa of caudal spinal trigeminal nucleus. We killed the rats which survived for 2-30 days after their infraorbital nerves were cut off. The results were as follows: (1) The transganglionic degeneration of infraorbital nerves was characterised mainly by the clustering and fusion of synaptic vesicles and the formation of alveoli in degenerated vesicles, but no increased neurofilaments occurred. (2) The mitochondria in some of the degenerated terminals became obviously swollen and darkened, and appeared in the shape of sphere. (3) The large dense cored vesicles degenerated more slowly than the synaptic vesicles. (4) In the course of axonal terminals degeneration, the large dense cored vesicles within the terminals still released their transmitters at the nonsynaptic site. (5) In the substantia gelitinosa, the degenerated terminals formed three types of synapses, axo - dendritic, axo -somatic and axo-axonic, and participated in the formation of the synpatic complexes.