ELECTRON MICROSCOPIC STUDY OF THE RELATIONSHIP BETWEEN CATECHOLAMINERGIC AND PEPTIDERGIC NERVE TERMINALS IN THE RAT NEUROHYPOPHYSIS / 解剖学报

ABSTRACT

In order to clarify the regulatory mechanism of the neurohormone releasing in the neurohypophysis, the immunohistochemical and chemical lesion method were combined to demonstrate the vasopressin (VP)-and catecholamine (CA)-containing nerve terminals, and their distribution and relationship were observed under electron microscopic level. The results showed that in the rat neurohypophysis there were not only widely distributed VP nerve terminals, but also there were many 6-OHDA induced degenerated nerve endings. The close relationship even synapse-like contacts existed between the CA-ergic endings and pituicytes as well as microglial cells. It was very interesting that the CA-ergic boutons formed axoaxonic synapses with VP-containing boutons. In this case, the CA-bouton was presynaptic element whereas the VP-bouton served as postsynaptic element. The above mentioned results probably provided ultrastructural evidence for the regulatory mechanism of the neurohormone releasing in the neurohypophysis for the first time.