Epileptic Focus Stimulation and Seizure Control in the Rat Model of Kainic Acid-Induced Limbic Seizures

Abstract

The inhibitory effects of deep brain stimulation (DBS) were investigated in a rat model of kainic acid (KA)-induced limbic status epilepticus. Wistar rats were injected with 1.0 microg KA into the left amygdala after stereotactic implantation of a guide cannula and electrodes. Bipolar rectangular pulses of 0.1 msec duration and 0.1-0.3 mA amplitude were applied intermittently to the left amygdala (10 Hz or 130 Hz), left ventral hippocampus (10 Hz), and left dorsomedial thalamus (130 Hz). Seizure frequency was evaluated by video electroencephalography monitoring and compared to control animals that did not receive DBS. All rats developed limbic status epilepticus 60-90 minutes after KA injection. Seizure frequency was significantly reduced by 10 Hz stimulation of the amygdala and by 130 Hz stimulation of the dorsomedial thalamus. No significant effects were observed with other types of stimulation. Seizure behaviors or duration of seizure were not changed significantly by DBS treatment. DBS of an epileptic focus may attenuate KA-induced limbic seizures, depending on the stimulation sites and parameters.