A DOUBLE LABELED IMMUNOELECTRON MICROSCOPIC STUDY OF NEUROTENSINERGIC AND SUBSTANCE P-ERGIC STRUCTURES IN THE RAT ARCUATE NUCLEUS / 解剖学报

ABSTRACT

The distributions of neurotensin(NT) and substance P(SP) in the arcuate nucleus of rat hypothalamus have been studied by means of double labeled pre-embedding immunoelectron microscopic technique. It was observed that there were SP- and NT-containing dendrites, perikarya and axons in the arcuate nucleus. SP- and NT-containing dendrites and axons received asymmetric afferent synapses from immunonegative axons. SP-positive axonal terminals established symmetric axo-somatic and axo-dendritic synapses with immunonegative perikarya and dendrites as well as symmetric axo-somatic synapses with NT-positive perikarya. The results of this study directly indicate for the first time that the NT-ergic neurons in rat arcuate nucleus receive innervation from SP-ergic neurons, and provided an ultrastructural evidence for the synaptic regulation of the neuroendocrine of the hypothalamus.