摘要目的 研究大鼠海马源神经干细胞(NSC)分化前及其体外诱导分化的神经元样细胞在不同发育阶段延迟整流钾电流(IDR)的电生理特性.方法 利用无血清培养、单细胞克隆技术,体外培养SD大鼠海马组织源NSC.应用膜片钳技术全细胞模式记录IDR的电生理特性.结果 IDR的电流密度在NSC分化前和体外分化(DIV)0～6 d分别为45 pA/pF±4 pA/pF和56 pA/pF±10 pA/pF(+50 mV,标本数=9),而在DIV＞6 d的发育过程中保持稳定;IDR的半数最大激活膜电位(V1/2)在NSC分化前和DIV 0～6 d分别为9 mV±3 mV和12 mV±3 mV(标本数=9,P＜0.05),激活曲线右移,斜率参数K值无明显改变,但IDR激活特性在DIV＞6 d的发育过程中无明显改变;IDR的失活特性NSC分化前后及不同发育阶段的神经元样细胞中均无改变.结论 NSC分化/发育过程中,IDR的特性改变均发生在DIV 0～6 d,提示IDR通道在神经发育过程中发挥作用,且发育初始阶段对于细胞功能的成熟尤为重要.

abstractsObjective To study the developmental electrophysiological properties of delayed rectifier outward K+currents(IDR)in undifferentIA ted NSC and NSC-derived neurons at various time points of adult SD rat hippocampus in vitro.Methods Neural stem cells were isolated from the hippocampus of adult SD rats with serum-free incubation and single-cell cloning technique.Electrophysiological recordings of IDR were performed using whole-cell patch clamp.Results The current density of IDR increased in NSC-derived neurons DIV 0-6 d whereas remained constant in DIV＞6 d.The current density of IDR at+50 mVwas 45 pA/pF±4 pA/pF and 56 pA/pF±10 pA/pF in undifferentIA ted NSCs and NSC-derived neurons DIV 0-6 d respectively(n=9).The activation process of IDR was also ahered in DIV 0-6 d whereas remained constant in DIV＞6 d.The positive shift in steady-state activation curve of IDR revealed an increase 0f V1/2,however the slope factors K remained unchanged.V1/2 Was 9 mV±3 mV and 12 mV±3 mV in undifierentIA ted NSCs and NSC-derived netrrons DIV 0-6 d respectively(n=9,P＜0.05)The inaetivation properties of IDR were not altered before and after differentIA tion.Conclusion Electrophysiological characteristics of IDR were all altered in DIV 0-6 d,suggesting the essentIA l role of IDR in neurogenesis and early stage of differentIA tion/development process is very important for the functional mature of neuron.