Effect of amlodipine on EEG activity and EEG power spectra in penicillin-induced focal seizures in rats

Penicillin applied into the motoric cortex may induce focal spike activity. The aim of our study was to investigate whether amlodipine could prevent penicilIin induced excitatory changes in EEG activity. Experiments were performed on adult Wistar rats. They were anesthesized and placed in a stereotaxic apparatus. Vehicle or amlodipine (1 ; 3 ; 10 or 30 mg/kg) had been given 30 minutes prior to penicillin injection (2000 I.U.) into the left motoric cortex. In each rat four screw electrodes were placed over the left or right frontal and parietal cortex. The EEG was recorded in basal conditions and 5, 10, 15, 30 and 60 minutes after penicillin administration. The output from EEG machine was amplified and was transmitted to an IBM AT-compatible computer. The system was calibrated using 500 mV. Two 7.5 s samples of artefact free EEG were analyzed. In order to obtain power spectra between 0-30 Hz spectral averages were computed using Fast Fourier Transform. Individual EEG power of each frequency bin was normalized to average total power baseline. EEG frequencies were collapsed into 1 Hz bins. Our results demonstrate that amlodipine in doses of 10 and 30 mg/kg prevented the rise of EEG power spectra induced by focal penicillin administration.