下丘脑弓状核儿茶酚胺能神经支配的电镜细胞化学研究

ELECTRON MICROSCOPIC CYTOCHEMICAL STUDY OF CATECHOLAMINERGIC INNERVATION OF HYPOTHALAMIC ARCUATE NUCLEUS

6-OHDA was injected into the third cerebroventricle of rats.24 hours later,thanimals were sacrificed and the degeneration of catecholaminergic (CA) nerve term-inals were studied by electron microscopic cytochemical method.The results showedthat there were a number of degenerated nerve terminals in the arcuate nucleus.Thecharacteristics of these terminals were as follows:enhanced axoplasmic electron opa-sity,destroyed mitochondria and synaptic vesicles and the formation of dense bodies.The multilocular forms were commonly encountered.Most of degenerated terminalswere surrouded by processes of glial cells.The degnerated perikarya of the neuronsin arcuate nucleus with decreased RER,destroyed mitochondria and dense bodieswere also observed.Based on the characteristics of degenerated features the authorsbelieved that these damaged terminals should mainly belong to DA fibers.Theymight regulate or control the function of the arcuate nucleus by means of differentkinds of synaptic mechanisms.The source of DA nerve fibers may originate from A_(12)A_(14) or A_(15) cell groups of the hypothalamus.