Abstract: Aim In order to study the mechanisms of underlying improving learning and memory in rodent,the effects of berberine (Ber)on EEG and EEG pow erspectrum were recorded in conscious rabbits.Methods EEG and EEG power spectrum were recorded in conscious rabbits with chronical implanted elect rodes.Results Ber at doses of 1~4mg·kg^-1iv showed to decrease dose-dependently the spect rum power of delta dominant frequency in cortical area and transfer the dominant frequency from delta to thetarhy thm in hippo campus.Under the same conditions,the effects of physostigmine 0.1mg·kg^-1iv on EEG were similar to Ber.Ber 2mg·kg^-1iv reversed significantly these effects of Ber 0.05 mg/rabbitivon EEG and power spectrum,but scopolamine butylbromide 0.4mg·kg^-1iv,which can not pass the blood-brain barrier,did not.Conclusion The effects of Ber are closely related to the action on the central cholinergic system.

Key words: berbe rine, EEG, learning and memory, rabbits