Opiocortin and catecholamine input to CRF-immunoreactive neurons in rat forebrain.
Neural input to distinct and separate populations of CRF-immunoreactive (ir) neurons in rat forebrain was investigated. The relationship of opiocortin and/or catecholamine fibers to different groups of CRF-containing neurons was elucidated using single and dual labeling immunocytochemical procedures. Antibodies to CRF, ACTH(1-39) and the catecholamine synthesizing enzymes which are tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT) were utilized. CRF-ir neuronal populations are localized predominantly in the following regions of rat forebrain: bed nucleus of stria terminalis, medial preoptic area, suprachiasmatic and paraventricular (PVN) nuclei of hypothalamus and central nucleus of amygdala. The present study demonstrates that CRF-ir neuronal groups in rat forebrain are not homogenous in that each population received a characteristic neural input. CRF-ir neurons in the PVN received a dense input of ACTH-, TH-, DBH-, and PNMT-ir fibers. In contrast, CRF-ir neurons in the central nucleus of amygdala are colocalized predominantly with TH-ir fiber/terminals. In the ventral portion of the bed nucleus of stria terminalis, TH-, ACTH- and DBH-ir fibers are demonstrated in close anatomical proximity to CRF-containing perikarya; in the dorsal portion of this nucleus, TH-ir fiber/terminals are colocalized with CRF-ir neurons. In the suprachiasmatic nucleus, neither opiocortin- nor catecholamine-immunostained fibers are observed in association with CRF-ir neurons. Our data suggest that there is a transmitter specificity of neural input to each CRF-ir neuronal population in rat forebrain.
Hornby
P J
PJ
Neuroendocrine Unit, University of Rochester, NY 14642.
Piekut
D T
DT
D000818:Animals; D001921:Brain / Q000166:cytology; D001923:Brain Chemistry / Q000502:physiology; D002395:Catecholamines / Q000032:analysis* / Q000502:physiology; D003346:Corticotropin-Releasing Hormone / Q000032:analysis*; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000032:analysis*; D010907:Pituitary Hormones / Q000032:analysis* / Q000502:physiology; D011333:Pro-Opiomelanocortin; D051381:Rats; D011919:Rats, Inbred Strains
D002395:Catecholamines; D010907:Pituitary Hormones; D011333:Pro-Opiomelanocortin; D003346:Corticotropin-Releasing Hormone