[An analysis of the differences in the effects of diazepam on the EEG of noninbred white rats with high and low expression of anxiolytic action in a conflict situation].

The effects of diazepam (5 mg/kg, i.p.) on the EEG power spectra of the sensorimotor cortex and the dorsal hippocampus were studied in albino rats with different types of conflict behaviour. "Active" rats were characterized by domination of the theta-activity in their background cortical EEG-spectra, "passive" ones--by that of the delta-activity. No differences were revealed in the background hippocampal EEG-spectra. Diazepam produced slowing of the theta-activity and increased the beta-activity in a band of 12-32 Hz in "active" rats and that in a band of 12-16 Hz in "passive" ones. The finding is usefull for studying individual animal sensitivity to drugs effects.