Guo Hong-bo, Zou Fei
Department of Scientific Research, Zhu-Jiang Hospital, Southern Medical University, Guangzhou 510282, China.
Zhonghua Yi Xue Za Zhi. 2008 Apr 15;88(15):1071-5.
To study the developmental electrophysiological properties of delayed rectifier outward K+ currents (IDR) in undifferentiated NSC and NSC-derived neurons at various time points of adult SD rat hippocampus in vitro.
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.
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 mV was 45 pA/pF +/- 4 pA/pF and 56 pA/pF +/- 10 pA/pF in undifferentiated NSCs and NSC-derived neurons DIV 0-6 d respectively (n = 9). The activation process of IDR was also altered 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 of V1/2, however the slope factors K remained unchanged. V1/2 was 9 mV +/- 3 mV and 12 mV +/- 3 mV in undifferentiated NSCs and NSC-derived neurons DIV 0-6 d respectively (n = 9, P < 0.05). The inactivation properties of IDR were not altered before and after differentiation.
Electrophysiological characteristics of IDR were all altered in DIV 0-6 d, suggesting the essential role of IDR in neurogenesis and early stage of differentiation/development process is very important for the functional mature of neuron.
研究成年SD大鼠海马体外培养中未分化神经干细胞（NSC）及NSC源性神经元在不同时间点延迟整流外向钾电流（IDR）的发育电生理特性。
采用无血清培养和单细胞克隆技术从成年SD大鼠海马分离神经干细胞。运用全细胞膜片钳技术对IDR进行电生理记录。
NSC源性神经元在第0 - 6天IDR电流密度增加，而在第6天之后保持恒定。在+50 mV时，未分化NSC和第0 - 6天的NSC源性神经元中IDR电流密度分别为45 pA/pF±4 pA/pF和56 pA/pF±10 pA/pF（n = 9）。IDR的激活过程在第0 - 6天也发生改变，而在第6天之后保持恒定。IDR稳态激活曲线的正向偏移显示V1/2增加，但斜率因子K保持不变。未分化NSC和第0 - 6天的NSC源性神经元中V1/2分别为9 mV±3 mV和12 mV±3 mV（n = 9，P < 0.05）。IDR的失活特性在分化前后未改变。
IDR的电生理特性在第0 - 6天均发生改变，提示IDR在神经发生及分化/发育早期过程中的重要作用，对神经元功能成熟非常重要。
