Ultrastructural demonstration of ovine CRF-like immunoreactivity (oCRF-LI) in the rat hypothalamus: processes of magnocellular neurons establish membrane specializations with parvocellular neurons containing oCRF-LI.
Ovine corticotropin releasing factor-like (oCRF-LI) immunoreactivity was detected in the rat hypothalamus by immunocytochemistry. The unlabeled antibody peroxidase-antiperoxidase method was applied in 40 microM vibratome sections before embedding for examination under the electron microscope. Immunoreactivity was found in axons of the median eminence and the neural lobe, as well as in cell bodies and dendrites of parvocellular neurons the in paraventricular nucleus. Axon terminals in the external zone of the median eminence and in the neural lobe frequently abutted on the pericapillary space, suggesting the possible release of oCRF-LI into the fenestrated capillaries. Labeled cells in the paraventricular nucleus synapsed with unlabeled nerve terminals and were found in synaptic-like contact with protrusions of magnocellular neurons. The latter finding might represent the morphological basis for orthodromic interactions between parvocellular and magnocellular neurons of the paraventricular nucleus, which have been previously demonstrated by electrophysiological methods.
D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000032:analysis*; D005260:Female; D007031:Hypothalamus / Q000648:ultrastructure*; D007124:Immunoenzyme Techniques; D008297:Male; D008854:Microscopy, Electron; D009474:Neurons / Q000648:ultrastructure*; D009928:Organ Specificity; D051381:Rats; D011919:Rats, Inbred Strains; D012756:Sheep
D003346:Corticotropin-Releasing Hormone