Krieger C, Sears T A
Sobell Department of Neurophysiology, Institute of Neurology, London, UK.
Can J Physiol Pharmacol. 1988 Oct;66(10):1328-36. doi: 10.1139/y88-217.
The development of voltage-dependent ionic conductances of foetal mouse spinal cord neurones was examined using the whole-cell patch-clamp technique on neurones cultured from embryos aged 10-12 days (E10-E12) which were studied between the first day in vitro (V1) to V10. A delayed rectifier potassium conductance (Ik) and a leak conductance were observed in neurones of E10, V1, E11, V1, and E12, V1 as well as in neurones cultured for longer periods. A rapidly activating and inactivating potassium conductance (IA) was seen in neurones from E11. V2 and E12, V1 and at longer times in vitro. A tetrodotoxin (TTX) sensitive sodium-dependent inward current was observed in neurones of E11 and E12 from V1 onwards. Calcium-dependent conductances were not detectable in these neurones unless the external calcium concentration was raised 10-to 20-fold and potassium conductances were blocked. Under these conditions calcium currents could be observed as early as E11. V3 and E12, V2 and at subsequent times in vitro. The pattern of development of voltage-dependent ionic conductances in murine spinal neurones is such that initially leak and potassium currents are present followed by sodium current and subsequently calcium current.
采用全细胞膜片钳技术，对来自10 - 12天龄胚胎（E10 - E12）、在体外培养第1天（V1）至V10期间进行研究的胎鼠脊髓神经元电压依赖性离子电导的发育情况进行了检测。在E10、V1、E11、V1和E12、V1的神经元以及培养更长时间的神经元中均观察到延迟整流钾电导（Ik）和漏电流。在E11、V2和E12、V1的神经元以及体外培养更长时间时，观察到快速激活和失活的钾电导（IA）。从V1开始，在E11和E12的神经元中观察到对河豚毒素（TTX）敏感的钠依赖性内向电流。除非将细胞外钙浓度提高10至20倍并阻断钾电导，否则在这些神经元中检测不到钙依赖性电导。在这些条件下，最早在E11、V3和E12、V2以及随后的体外培养时间可以观察到钙电流。小鼠脊髓神经元电压依赖性离子电导的发育模式是，最初存在漏电流和钾电流，随后出现钠电流，接着是钙电流。
