左乙拉西坦对癫痫小鼠内嗅皮层GABA神经元电生理干预的研究

Electrophysiological changes of GABAergic neurons of entorhinal cortex in epileptic mouse after levetiracetam intervention

目的研究癫痫小鼠内嗅皮层γ-氨基丁酸(GABA)能神经元的电生理变化及使用左乙拉西坦(Lev)干预治疗后的电生理变化。方法将绿色荧光蛋白转基因(FVB-Tg)小鼠随机分为对照组、模型制备组和Lev干预组。Lev采用灌胃给药。在造模成功后直接断头取脑,制作脑片,在人工脑脊液中孵育后,利用膜片钳技术,进行全细胞记录。观察并比较3组小鼠大脑内嗅皮层GABA能神经元动作电位的阈电位(Vts)、静息膜电位(Vr)、绝对不应期(ARP)和动作电位间距(ISI)。结果模型制备组ARP值较对照组和Lev干预组延长,差异均有统计学意义(均P<0.05);Lev干预组较对照组仅ARP4比较差异有统计学意义(P<0.05)。模型制备组Vts-Vr值较对照组明显延长,但Lev干预组Vts-Vr值较对照组及模型制备组明显缩短,差异均有统计学意义(均P<0.05)。模型制备组ISI值较对照组和Lev干预组延长,差异均有统计学意义(均P<0.05),Lev干预组与对照组比较,差异均无统计学意义(均P>0.05)。结论 Lev干预能使癫痫小鼠内嗅皮层GABA能神经元Vts-Vr、ARP、ISI缩短,有增强GABA能神经元兴奋性和编码能力的作用。

Objective To investigate the electrophysiological changes of GABAergic neurons in entorhinal cortex ofepileptic mouse after levetiracetam intervention.Methods Transgenic FVB-Tg mice were randomly divided into control group,model group,and levetiracetam group.The epilepsy model was induced by sequential injection of scopolamine and pilocarpinein TVB-Tg mice.Levetiracetam was given by intragastric administration.Tissue specimens of entorhinal cortex were obtainedafter animals were sacrificed.The brain slices(400滋m)were prepared and incubated in oxygenated artificial cerebrospinal fluid.The sequential spike patters(inter-spike intervals,ISI)and intrinsic properties(ARP,Vts,Vr)of GABAergic neurons were recordedby the whole-cell clamp and analyzed with pClamp9.Results Compared to control groups,in model group the ARP wasprolonged,the Vts-Vr increased,and the ISI was extended(all P<0.05).Compared to model group,in levetiracetam group theARP were significantly shortened(P<0.05),the threshold potentials significantly decreased(P<0.01),and the ISI was shortened(P<0.05).Conclusion With the intervention of levetiracetam,the spike encoding and intrinsic properties of GABAergic neuronswere improved in epileptic mice,which suggests that the functional enhancement of GABAergic neurons may play an importantrole in epileptic control.