Catecholaminergic innervation of GRF-containing neurons in the rat hypothalamus revealed by electron-microscopic cytochemistry.
The catecholaminergic innervation of neurons containing growth hormone-releasing factor (GRF) was examined by use of a method which combined either 5-hydroxydopamine (5-OHDA) uptake or autoradiography after intraventricular injection of 3H-noradrenaline with immunocytochemistry for GRF in the same tissue sections at the electron-microscopic level. In the ventrolateral part of the arcuate nucleus of the rat hypothalamus a large number of immunonegative axon terminals were found to make synaptic contact with GRF-like immunoreactive (GRF-LI) cell bodies and processes. 3H-noradrenaline autoradiography or 5-OHDA-labeling combined with GRF immunocytochemistry revealed that axon terminals labeled with 3H-noradrenaline or 5-OHDA make synaptic contact with the GRF-LI nerve cell bodies and processes. These findings indicate that catecholamine-containing neurons innervate GRF neurons to regulate GRF secretion via synapses in the rat arcuate nucleus.
Sato
A
A
Department of Anatomy, Showa University School of Medicine, Tokyo, Japan.
Shioda
S
S
Nakai
Y
Y
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000032:analysis* / Q000166:cytology / Q000648:ultrastructure; D001345:Autoradiography; D001369:Axons / Q000648:ultrastructure; D002395:Catecholamines / Q000032:analysis*; D003712:Dendrites / Q000648:ultrastructure; D013007:Growth Hormone-Releasing Hormone / Q000032:analysis*; D006892:Hydroxydopamines; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D009474:Neurons / Q000032:analysis*; D009638:Norepinephrine; D051381:Rats; D011919:Rats, Inbred Strains
D002395:Catecholamines; D006892:Hydroxydopamines; C027802:5-hydroxydopamine; D013007:Growth Hormone-Releasing Hormone; D009638:Norepinephrine