Electroencephalographic Effects of Chlorpromazine in Rats

The effects of an antipsychotic, chlorpromazine, on the electroencephalogram (EEG) were observed while rats were awake but immobile. The time course and the dose-dependency of the EEG changes were examined. The method of the power spectrum analysis was used to examine the EEG changes by the drug. The bands were divided into delta $(1{\sim}3.5\;Hz),$ theta $(3.5{\sim}8\;Hz),$ alpha $(8{\sim}13\;Hz),$ beta1 $(13{\sim}21\;Hz),$ beta2 $(21{\sim}30\;Hz)$ and gamma $(30{\sim}50\;Hz).$ In rats, the low dose of chlropromazine (1 mg/kg, i.p.) produced a significant increase in the power of the beta1 band. The higher doses (5, 10 mg/kg, i.p.) produced a significant increase in the power of the delta, theta, alpha and beta1 bands, and the decrease in the power of the gamma band. The powers of the bands changed dose-dependently. Then, the authors discussed whether the EEG effects produced by a drug are associated with the accompanying behavioral changes specifically.