CHANGES IN LATE AUDITORY-EVOKED POTENTIALS INDUCED BY CORTICOTROPIN-RELEASING HORMONE AND CORTICOTROPIN FRAGMENT-4-9 IN MALE CONTROLS

In order to investigate influences of corticotropin-releasing hormone (CRH) and corticotropin fragment (adrenocorticotropic hormone, ACTH, 4 -9) on auditory perception processes, 10 subjects received either a pl acebo (sodium chloride 0.9%), CRH (100 mu g) or ACTH 4-9 (Hoe 427, 300 mu g) intravenously on different days. Late auditory evoked potential s (AEP) were computed and further analyzed using the brain electric so urce analysis method. As expected, CRH administration was followed by a rise in plasma cortisol and ACTH concentrations, whereas the injecti on of the ACTH 4-9 fragment did not alter plasma cortisol concentratio ns. In contrast to these different hormonal responses, both CRH and AC TH 4-9 modulated AEP in a similar manner, differing in quantity rather than in quality. The changes in AEP after the administration of ACTH 4-9 were most likely induced by a direct CNS action, whereas for the C RH effects, an indirect mechanism through the release of endogenous AC TH must be considered.