Visually evoked potentials in cortical and subcortical brain structures of conscious rabbits with chronically implanted electrodes. Standardized normal values and the influence of some psychopharmacological agents on them.

By means of a modified and simplified surgical and implantation technique, standardized values for visually evoked potentials (EP) from 7 brain structures (caudate nucleus, posterior hypothalamus, mesencephalic reticular formation, intra-laminar thalamic nuclei, amygdala, dorsal hippocampus and visual cortex) are obtained. The importance of a careful selection of the animal material, constant test conditions and the selection of test parameters as a prerequisite for the assessment of psychotropic drugs is emphasized and discussed. As an example of the specific influence on visually evoked potentials in the above named brain structures, the effects of haloperidol and amytriptyline on latencies and amplitudes of the individual parameters of EPs are described. It is assumed that the method described can be of great assistance for investigation and classification of newly developed substances.