SIMULTANEOUS QUANTITATIVE-EVALUATION OF VISUAL-EVOKED RESPONSES AND BACKGROUND EEG ACTIVITY IN RAT - NORMATIVE DATA

An integrated quantitative electroencephalography system (Phegra) for pharmacological and toxicological research in rat is described. Peak l atencies and amplitudes of visual-evoked potentials, occurrence, durat ion, and linear excursions of photically evoked afterdischarges, ''act ivity,'' ''mobility,'' ''complexity'' of Hjorth, and absolute spectral powers of delta, theta, alpha, and beta frequency bands of background activity of visual cortex and frontal-visual leads were measured in f reely moving rats. Counts of small and large movements were also regis tered. Data of baseline measurements performed in large amount of anim als are presented. None of the parameters except the occurrence of pho tically evoked afterdischarge and the linear excursion of its averaged waveshape changed significantly in five measurements performed within six hours following the intraperitoneal and oral administration of tw o commonly used drug vehicles.