Abstract
In the present study, the influences of cholinergic (ACh), dopaminergic (DA), noradrenergic, serotonergic and γ-aminobutyric acid (GABA) ergic system activation and blocking agents on the cortical (CT) and hippocampal (HC) EEG power spectra were investigated in rabbits. The AChergic agents, physostigmine and atropine, produced marked increases or decreases in peak powers, the changes of which were inversely related to each other, but similar to those of the normal behavioral states. The other agents did not always produce changes. ACh seems to play an important role in the regulation of peak powers. Apomorphine shifted the theta wave peak to higher frequencies and haloperidol shifted it to lower frequencies. The other drugs did not cause a shift. DA seems to regulate peak frequency. These findings suggest that ACh is important for the regulation of consciousness between the wakefulness and SWS states and suggest that DA is involved in the production of REM sleep.
