EFFECT OF CEREBELLAR STIMULATION ON EEG POWER SPECTRA IN THE ACUTE MODEL OF EPILEPSY

Experiments were performed to investigate the effects of cerebellar st imulation on epilepsy induced by parenteral administration of penicill in, in rats without or with the lesion of sensorimotor cortex. There w ere no differences in the EEG activity of the same experimental animal after the first and subsequent penicillin treatments (at least 7 days later). The electrical stimulation (duration of 5-10 min) of the late ral cerebellar nucleus was applied repetitively 135-315 min after peni cillin administration, when the EEG power spectra markedly increased. The cerebellar stimulation evoked the decrease of the mean total EEG p ower spectra, but the effects were temporary. The EEG power spectra we re significantly lower (P < 0.05) during the period of 150-330 min aft er penicillin treatment in experimental sessions with applied cerebell ar stimulation in comparison to the experimental sessions without such stimulation. The residual effects (if any) of cerebellar stimulation on the EEG activity in the later period, 345-600 after penicillin trea tment were not significant (P > 0.05). Cerebellar stimulation had the same effect among unlesioned animals and animals with prior cortical l esion in the acute model of epilepsy.