Effects of alpha helical CRF 9-41 on neurophysiological and autonomic patterns induced by CRF in the rabbit

The EEGraphic, behavioural and autonomic effects related to the separated and simultaneous central administration of CRF and CRF antagonist (alpha-helical CRF 9-41) were evaluated in the rabbit. CRF produced a decrease of cortical EEG power spectrum, a biphasic effect on the heart rate, a hyperthermia and tachypnoea. 9-41 CRF significantly increased the EEG power spectrum, but it did not affect the autonomic parameters. The simultaneous administration of these peptides resulted in a significative and rapid inhibition of all the CRF effects. The intrinsic properties of 9-41 CRF on EEG and the interaction with CRF were discussed.