Comparison of evoked potential changes from lateral geniculate body and visual cortex by stimulation of the medial septal nucleus and mesencephalic reticular formation in rabbits

: Evoked potentials to flash from visual cortex (VC) and corpus geniculatum laterale (Cgl) were observed in alert resting rabbits. The direction and volume of changes in the late negative complex (sn-) of the EP were investigated during repetition of light flashes only (habituation), during stimulation of septum and reticular stimulation (RFmes). Habituation showed an increase of amplitudes during the sn-complex, which was started first in Cgl, had its maximum earlier and lasted longer in the Cgl than in the visual cortex. Septal stimulation in the majority of experiments caused diminution of these EP-components almost synchronously in the VC and Cgl. Reticular stimulation gave rise to diminution of amplitudes during the sn-complex, which started first in the VC, where it had its maximum earlier and lasted longer than in the Cgl too. Our results show that all three influences under investigation caused typical but different changes of processes underlying EP of the visual cortex and lateral geniculate body.