The influence of diazepam on the electroencephalogram-evoked potential interrelation in rats.
Though being a sedative, diazepam increases beta-activity in the electroencephalogram (EEG). Diazepam also affects auditory evoked potentials (AEPs). We investigated if the effect of diazepam on AEPs could be ascribed to its beta-increasing effect. Eight rats received vehicle and diazepam counterbalanced. AEPs were ranked in ten categories according to the percentages of beta-activity in the pre-stimulus electroencephalogram (EEG). With vehicle, the P(29), N(51) and P(67) AEP components increased and cross-correlation coefficients (CCCs) declined with increasing beta-activity. With diazepam AEP components and CCCs remained unchanged. All AEPs with diazepam closely resembled the AEP of the lowest beta-category obtained with vehicle. We conclude that the effect of diazepam on AEPs can not be ascribed to its beta-enhancing effect. Diazepam disrupts the normal AEP-EEG relation such that diazepam-effects on AEPs seem to reflect the sedative effects of diazepam and not its beta-increasing effects.
Jongsma
M L
ML
Department of Anaesthesiology, University of Nijmegen, P.O. Box 9104, 6500HE, The, Nijmegen, Netherlands. jongsma@nici.kun.nl
van Rijn
C M
CM
van Egmond
J
J
van Schaijk
W J
WJ
Sambeth
A
A
Coenen
A M
AM
D000818:Animals; D001611:Beta Rhythm / Q000187:drug effects; D003975:Diazepam / Q000494:pharmacology*; D004569:Electroencephalography / Q000187:drug effects*; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D005583:Fourier Analysis; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008297:Male; D014677:Pharmaceutical Vehicles; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects
D006993:Hypnotics and Sedatives; D014677:Pharmaceutical Vehicles; D003975:Diazepam