Effect of low frequency electrical stimulation on spike and wave discharges of perioral somatosensory cortex in WAG/Rij rats

Low frequency electrical stimulation has been revealed that as a potential cure in patient with drug resistant to epilepsy. This study tries to evaluate the effect of low frequency electrical stimulation (LFS) on absence seizure of perioral region primary somatosensory cortex (S1po). Eighteen male WAG/Rij rats were received LFS (3 Hz, square wave, monophasic, 200 μs, and 400 μA) for 25 min into S1po for a period of five days. There is 6 animals per group .The stimulating electrodes were implanted according to stereotaxic landmarks and EEG recording was obtained 30 min before and after LFS to analyse frequency, number and duration of spike–wave discharges (SWD). The results showed that in animals with unilateral stimulating electrodes (Exp1) in first and second days and also in animals with bilateral stimulating electrodes (Exp2) in days 3rd and 4th. LFS had significant decrease effects (p < 0.05) on mean number of SWD between pre-LFS. In comparison pre-LFS to post-LFS, mean of duration in Exp2 decreased significantly. In continuous application of LFS (5 days) only the data of first day was differently significant (p < 0.05) but data of other days had no difference. Comparison of data between Exp1, Exp2 and control groups showed that the mean number of Exp1 was significantly different (p < 0.05) and mean pick frequency in Exp2 was significantly decreased in comparison with Exp1 group (p < 0.05). The LFS of S1po produces significant antiepileptic effect on absence seizure but it was not persistent till the next day and shows a short time effect.