RAPID STRESS-INDUCED ELEVATIONS IN CORTICOTROPIN-RELEASING HORMONE MESSENGER-RNA IN RAT CENTRAL AMYGDALA NUCLEUS AND HYPOTHALAMIC PARAVENTRICULAR NUCLEUS - AN IN-SITU HYBRIDIZATION ANALYSIS

High densities of nerve cells containing corticotropin-releasing hormo ne (CRH) are located in the central nucleus of the amygdala (CeA) and paraventricular nucleus (PVN) of the hypothalamus. These brain regions play an important role in activating autonomic, behavioral, and endoc rine responses to stress. This study was conducted to provide needed i nformation concerning the acute effects of stress on CeA and PVN CRH m RNA expression. Rats were exposed to restraint stress for 1 h and brai ns collected after a 1-h post-stress interval. CRH mRNA expression occ urring in the CeA and PVN was examined using in situ hybridization tec hniques. Densitometric analysis revealed that acute restraint stress p roduced significant increases in CRH mRNA levels in the PVN and in the rostral CeA region. In addition, the area in the rostral CeA encompas sing high CRH mRNA signals increased significantly after stress. Resul ts provide clear evidence that CRH neurons in the CeA and PVN exhibit rapid increases in CRH mRNA expression after exposure to stress. (C) 1 998 Elsevier Science B.V.