Effects of diazepam on auditory evoked potentials of rats elicited in a ten-tone paradigm.
The effect of diazepam on sensory gating was studied in rats by measuring diazepam effects on auditory evoked potentials (AEPs) elicited in a ten-tone paradigm. Trains of 10 repetitive tone-pip stimuli were presented. Rats (n = 8) received 4 mg x kg(-1) diazepam subcutaneously or vehicle, counterbalanced over two sessions. Diazepam decreased the amplitude of the middle-latency P30 component and increased the amplitudes of the late-latency N60 and P67 components. The increase in the late-latency components might be due to a diazepam-induced decrease in arousal. Stimulus repetition decreased the amplitudes of the middle-latency N18 and P30 components in both conditions. This suggests that automated neuronal recovery functions underlying sensory gating remain intact with diazepam. In the vehicle condition, the amplitude of the late-latency P67 decreased with stimulus repetition, but not in the diazepam condition. This suggests a diazepam-induced decrease of behaviourally mediated habituation.
Jongsma
M L
ML
Department of Anaesthesiology, Njimegen Institute for Cognition and Information, University of Nijmegen, The Netherlands. jongsma@nici.kun.nl
van Rijn
C M
CM
van Schaijk
W J
WJ
Coenen
A M
AM
D000161:Acoustic Stimulation; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001288:Attention / Q000187:drug effects*; D003975:Diazepam / Q000494:pharmacology*; D018913:Event-Related Potentials, P300 / Q000187:drug effects; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D006185:Habituation, Psychophysiologic / Q000187:drug effects; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects
D014151:Anti-Anxiety Agents; D003975:Diazepam