Effect of electroacupuncture stimulation of hindlimb on seizure incidence and supragranular mossy fiber sprouting in a rat model of epilepsy

Abstract

Recently, electroacupuncture (EA) has been gaining more and more attention as a treatment for epilepsy. However, concrete evidence is needed to better understand its antiepileptic effect and the mechanism underlying this effect. The present study was designed to assess the effect of EA stimulation of hindlimb on the incidence of behavioral seizures (spontaneous recurrent seizures, [SRS]) and electroencephalogram (EEG) seizures, and the extent of supragranular mossy fiber sprouting (MFS) using the lithium-pilocarpine rat model of epilepsy. Sham EA at the same point without electrical stimulation was set as the control. EA and the sham EA were performed bilaterally (at the symmetrical Zusanli acupoints on both hind legs) 30 times every two days. The numbers of behavioral seizures and EEG seizures were then analyzed to evaluate the antiepileptic effect. After confirmation of the antiepileptic effect, MFS in the dentate gyrus (DG) supragranular layer was investigated by Timm's staining. The results showed that the EA stimulation of hindlimb significantly reduced the behavioral seizures, EEG seizures, and supragranular MFS; however, the sham EA without electrical stimulation showed no significant effect on seizures or supragranular MFS. The findings indicate that EA stimulation of hindlimb possesses an antiepileptic effect, which is probably related to its suppressive effect on aberrant MFS in DG.