FOCAL CEREBRAL-ISCHEMIA INDUCES CRH MESSENGER-RNA IN RAT CEREBRAL-CORTEX AND AMYGDALA

CORTICOTROPIN-releasing hormone (CRH) antagonism has neuroprotective e ffects in models of ischemia. We examined CRH mRNA by in situ hybridiz ation in a well-established rat model of focal cerebral ischemia cause d by permanent middle cerebral artery occlusion (MCAo). In ischemic co rtex CRH mRNA levels were elevated 2.6-fold 60 min after MCAo, compare d with sham operated animals. CRH mRNA was also induced in the amygdal a, 60 min following ischemia, in a pattern which was qualitatively dif ferent from that of sham operated animals. This rapid and profound inc rease in CRH mRNA levels during focal cerebral ischemia is likely to b e associated with neurotoxicity, as CRH antagonism has been reported t o cause a significant reduction in neuronal loss during ischemia.