The effects of alcohol and atropine on EEG and behavior in the rabbit

Electroencephalographic (EEG) activity was recorded from hippocampus and neocortex of rabbits. It was found that movement, movement-related 6–12 Hz rhythmical slow actvity (RSA), and movement-related neocortical desynchronization were unaffected by intravenous atropine sulfate but depressed by ethyl alcohol (ethanol). Slower 4–8 Hz immobility-related RSA and immobility-related neocortical desynchronization produced by sensory stimulation (visual, auditory, tactle, vestibular) were relatively unaffected by ethanol even at high (0.1–0.2 g-%) blood alcohol levels, but were abolished by atropine sulfate. The results provide evidence for the idea of two pharmacologically separable cortical activating systems and suggest that ethanol has a greater effect on noncholinergic than cholinergic systems.