The effects of low-frequency electric stimulus on hippocampal of Effects of low-frequency electric stimulus on hippocampal of α5 subunit of extra synapse GABAA receptor in kainic acid-induced epilepsy rats

Abstract

To explore the effects of low-frequency electric stimulus (LFS) on hippocampal of α5 subunit of extrasynaptic GABAA receptor in kainic acid-induced epilepsy rats and explore the possible mechanism of LFS on hippocampus to treat epilepsy. A total of 32 male Sprague-Dawley rats were divided randomly into 4 groups:epileptic, pseudo-surgery, LFS treatment and control. The expression of α5 subunit of extrasynaptic GABAA receptor and the association with the curative effects of LFS were evaluated by behavioristics, real-time fluorogenic quantitative polymerase chain reaction (PCR) and Western blot. After treatment, the number of seizures in LFS group were significantly lower than that in the epileptic and pseudo-surgery groups (2.88 ± 0.83 vs 8.50 ± 0.93 and 8.88 ± 0.83) (P < 0.01). The results of real-time PCR demonstrated that the expression of mRNA of α5 subunits in LFS treatment group was obviously higher than that in epileptic and pseudo-surgery groups (0.74 ± 0.20 vs 0.30 ± 0.16 and 0.31 ± 0.16) (P < 0.01), but was lower than 1.10 ± 0.23 in control group. Western blot demonstrated that the protein expression of α5 subunits in LFS (0.75 ± 0.09) and control (0.88 ± 0.09) groups were dramatically higher than that in epileptic (0.22 ± 0.08) and pseudo-surgery (0.26 ± 0.08) groups (P < 0.01). Low-frequency electric stimulus on hippocampus is effective in controlling epileptic seizures. And the mechanism may be related with the expression level of α5 subunits of extrasynaptic GABAA receptor.