The effect of parameters of low-frequency electrical stimulation on piriform-cortex kindled seizures in rat

Introduction: Electrical low-frequency stimulation (LFS) has antiepileptic effect, but the role of different stimulation parameters on this effect has not been determined. In this study the effect of different LFS parameters (intensity, pulse duration and train duration) on piriform-cortex kindled seizures was investigated. Methods: Seizure was produced in animals using kindling model of epilepsy. Then, the effect of LFS on seizure severity was investigated. Results: Different patterns of LFS (1 Hz) applied immediately before kindling stimulation in fully kindled animals, had no significant effect on seizure parameters. In the second experiment, effect of LFS (1 Hz) on inter-seizure interval was investigated. Data showed that daily stimulation of animals for 15 min with LFS for one week after the last kindling stimulation reduced significantly stage 5 seizure duration. Application of the same LFS protocols for three days and two weeks had no significant effect on seizure parameters. In the third experiment, effect of LFS (1 Hz) on kindling rate was investigated. Results showed that when LFS was delivered daily after each kindling stimulation it could decrease afterdischarge duration in various days during kindling and delayed the appearance of seizure stages 1 and 2 significantly. Conclusion: It may be concluded that LFS has antiepileptic effects on kindling acquisition and inter-seizure interval in kindled animals and that the characteristics of LFS protocol (intensity, pulse duration and train duration) have an essential role on these effects.