Expression Of The δ And α₅Subunit Of The GABA_A Receptor In The Hippocampus Induced By The Insular Epilepsy Rats

Objective Stimulate Sprague-Dawley Rat granular insular cortex to establish chronicEpilepsy Model. we try to visualize study the expression of δ and α5subunit in thehippocampus and dentate gyrus,to investigate the expression of δ and α5subunit in insularepilepsy and to investigate possible nosogenesis of insular epilepsy.Methods1. Establishment of Rat insular chronic Epilepsy Model:48maleSprague-Dawley rats were divided into kindled group and sham-operated group and controlgroup randomly. Kindled group: chronic insular electrical kindled models of rats wereestablished by using electrical stimulation. Sham-operated group: this group was establishedby using the same method of the kindled group without electrical stimulation. Control group:without surgery. Bipolar electrodes were implanted into left granular insular cortex，andkindling group were stimulated at1.5times of after discharge threshold twice daily toestablish chronic Epilepsy Model. Stimulus train consisted of1-ms (square biphasic) pulses at60Hz, with train duration of1s. Another stimulus of the same intensity was used after amonth to see the stabilization of the model2.The expression of δ and α5subunit in the kindling model:48male adult rats, weredivided in to kindled group and sham-operated group and control group randomly. Bipolarelectrodes were implanted into left granular insular cortex， and kindling group werestimulated at1.5times of afterdischarge threshold twice daily to establish chronic EpilepsyModel. Stimulus train consisted of1-ms (square biphasic) pulses at60Hz, with train durationof1s. Sham-operated group use the same method to the kindled group without electrical stimulation. Rats were killed painless, Using Nissl staining, the number of hippocampalneurons of rat epilepsy group, Sham-operated group and control group were detected; Usingimmunohistochemistry, the expression of δ and α5subunit of hippocampus of these groupswas tested; Using q-PCR, mRNA of δ and α5subunit of hippocampus of these groups wasdecapitated.Results1. Chronic Epilepsy Model is succeeded by Stimulating Sprague-Dawley Ratleft granular insular cortex. In a quiet state, low frequency of EEG in normal rats,with10Hz,low frequency,energy is also low,when Ⅴ grade the frequency of EEG increased attack to30Hz,and energy is greatly enhanced. The rats can reachⅤgrade throgh a period of kindling,Another stimulus of the same intensity was used after a month that can reachⅤgrade.2. The findings of Nissl staining showed that there is no significant difference of thenumber of neurons of the hippocampus between epileptic rats and normal rats(P>0.05). Thefindings of q-PCR showed that mRNA of δ and α5subunit of the hippocampus ofsham-operated group and control group represented much more than that of kindled groupafter7days which were kindled successfully(P<0.01). The findings of immunohistochemistryshowed that expression of δ and α5subunit of the hippocampus of sham-operated group andcontrol group represented much more than that of kindled group after7days which werekindled successfully(P<0.01)..Conclusions δ and α5subunit may play an important role in Insular Epilepsy; δ and α5subunit may be involved in insular epilepsy.