CORTICOTROPIN-RELEASING FACTOR IN THE LOCUS-COERULEUS MEDIATES EEG ACTIVATION-ASSOCIATED WITH HYPOTENSIVE STRESS

Although corticotropin-releasing factor (CRF) is thought to act as a n eurotransmitter to activate the locus coeruleus (LC) during hypotensiv e stress, the consequences of LC activation by CRF are unknown. In the present study a hypotensive challenge that activated rat LC neurons a lso produced cortical electroencephalographic (EEG) correlates of arou sal. Selective, bilateral LC inactivation by local clonidine infusion prevented EEG activation associated with hypotension. Additionally, bi lateral LC infusion of CRF antagonists prevented both LC and EEG activ ation by this challenge. These results indicate that CRF, acting as a neurotransmitter to activate LC during stress, has a powerful modulato ry influence over global forebrain electrophysiological activity.