Changes in frequency of seizure-like events in stimulated cortical slices.

Epilepsy affects nearly 3 million people in the United States alone. Given the fact that many people suffer from seizures that are intractable to pharmacological intervention, research groups are investigating the use of electrical stimulation to interact with and ameliorate symptoms of epileptic seizures. In mouse cortical slices made seizuregenic through chemical means, we applied precision controlled current pulses and measured local field potentials through a four point probe system to investigate the response of seizing tissue to electrical stimulation. We have determined that the frequency of the spontaneous seizure-like events may be modified by low amplitude, current controlled stimulation (0.5 microA). Differently from previously thought, this change in frequency is however not accompanied by any alteration of the tissue permittivity or conductivity during the inter-seizure interval.