Classification of drugs by stereotactic recording of focal brain activity in the rat (stereo-EEG).

A new electrophysiological model is described in which different types of psychoactive drugs can be differentiated from each other in the rat. Simultaneous focal recording of electrical activity from three brain regions in the presence of accumulating drug actions is followed by a calculation of the EEG power density spectrum. Division of the spectrum into 5 frequency bands for each brain region allows to evaluate a total of 15 variables. The values obtained after the last of 8 drug dosages are taken for a stepwise discriminant analysis. A distinct separation of amphetamine, chlorpromazine, diazepam and imipramine from placebo is achieved. The discriminant function obtained will serve for further drug classification.