Centrally administered orexin-A activates corticotropin-releasing factor-containing neurons in the hypothalamic paraventricular nucleus and central amygdaloid nucleus of rats: possible involvement of central orexins on stress-activated central CRF neurons.
We examined the effects of centrally administered orexin-A on corticotropin-releasing factor (CRF)-containing neurons in the hypothalamic paraventricular nucleus (PVN) and the central amygdaloid nucleus (CeA) of rats, using dual immunostaining for CRF and Fos. Ninety minutes after intracerebroventricular administration of orexin-A, approximately 96% and 45% of CRF-containing neurons expressed Fos-like immunoreactivity (LI) in the PVN and the CeA, respectively. We also examined the effects of immobilized stress and cold exposure on orexin-A-containing neurons in the rat hypothalamus using dual immunostaining for orexin-A and Fos. After immobilized stress for 20 min and cold exposure at 4 degrees C for 30 min, approximately 24% and 15% of orexin-A-containing neurons expressed Fos-LI, respectively. These results suggest that orexins in the central nervous system may be involved in the activation of central CRF neurons induced by stress.
Sakamoto
Fumihiko
F
Department of Occupational Health, Matsushita Science Center of Industrial Hygiene, 7-6 Tonoshima-cho, Kadoma 571-0045, Japan.
Yamada
Seiji
S
Ueta
Yoichi
Y
D000679:Amygdala / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000601:surgery; D002404:Catheterization; D002452:Cell Count; D002490:Central Nervous System / Q000187:drug effects / Q000378:metabolism; D003080:Cold Temperature; D003346:Corticotropin-Releasing Hormone / Q000032:analysis / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D007276:Injections, Intraventricular; D047908:Intracellular Signaling Peptides and Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology*; D000068797:Orexins; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological / Q000378:metabolism / Q000503:physiopathology; D013696:Temperature
D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D016760:Proto-Oncogene Proteins c-fos; D003346:Corticotropin-Releasing Hormone