Effects of transcranial focal electrical stimulation alone and associated with a sub-effective dose of diazepam on pilocarpine-induced status epilepticus and subsequent neuronal damage in rats

Experiments were conducted to evaluate the effects of transcranial focal electrical stimulation (TFS) applied via tripolar concentric ring electrodes, alone and associated with a sub-effective dose of diazepam (DZP) on the expression of status epilepticus (SE) induced by lithium-pilocarpine (LP) and subsequent neuronal damage in the hippocampus. Immediately before pilocarpine injection, male Wistar rats received TFS (300 Hz, 200 mu s biphasic square charge-balanced 50-mA constant current pulses for 2 mm) alone or combined with a sub-effective dose of DZP (0.41 mg/kg, i.p.). In contrast with DZP or TFS alone, DZP plus TFS reduced the incidence of, and enhanced the latency to, mild and severe generalized seizures and SE induced by LP. These effects were associated with a significant reduction in the number of degenerated neurons in the hippocampus. The present study supports the notion that TFS combined with sub-effective doses of DZP may represent a therapeutic tool to induce anticonvulsant effects and reduce the SE-induced neuronal damage. (C) 2013 Elsevier Inc. All rights reserved.