The rat brain neurons isolated from 15—17-day embryos were grown in dissociated cell culture and maintained in vitro for 3 weeks, The developmental process of the neurons was observed from the early stage of developm...The rat brain neurons isolated from 15—17-day embryos were grown in dissociated cell culture and maintained in vitro for 3 weeks, The developmental process of the neurons was observed from the early stage of development in terms of passive and active electrical parameters and their changes induced by perfusion of ionic channel blockers.The neurons' development could be morphologically divided into stages Ⅰ (from seedling to 5 days), Ⅱ (7—11 days), Ⅲ (12—20 days)andlV (21—22 days). The relative values of resting membrane potentials (RMP) for stages Ⅰ, Ⅱ, Ⅲ and Ⅳ were 1, 3.46, 4.07 and 6.54, respectively; the corresponding values of input resistance (Rin) were 10 1.48, 2.53 and 4.56, respectively. The current-voltage relationship in stages Ⅱ and Ⅲ was exponential in the direction of depolarization and the Rin's change with time was nearly linear. Spontaneous activities increased with prolongation of culture and the amplitude of evoked action potentials reached the maximum during stages Ⅲ and Ⅳ. The RMP and Rin were markedly decreased by perfusion of TEA while no change was seen in TTX perfusion group.The results indicate that potassium ionic channels develop slower in stages Ⅱ and Ⅳ, faster in stages Ⅰ and Ⅲ and mature by the end of stage Ⅳ.展开更多
文摘The rat brain neurons isolated from 15—17-day embryos were grown in dissociated cell culture and maintained in vitro for 3 weeks, The developmental process of the neurons was observed from the early stage of development in terms of passive and active electrical parameters and their changes induced by perfusion of ionic channel blockers.The neurons' development could be morphologically divided into stages Ⅰ (from seedling to 5 days), Ⅱ (7—11 days), Ⅲ (12—20 days)andlV (21—22 days). The relative values of resting membrane potentials (RMP) for stages Ⅰ, Ⅱ, Ⅲ and Ⅳ were 1, 3.46, 4.07 and 6.54, respectively; the corresponding values of input resistance (Rin) were 10 1.48, 2.53 and 4.56, respectively. The current-voltage relationship in stages Ⅱ and Ⅲ was exponential in the direction of depolarization and the Rin's change with time was nearly linear. Spontaneous activities increased with prolongation of culture and the amplitude of evoked action potentials reached the maximum during stages Ⅲ and Ⅳ. The RMP and Rin were markedly decreased by perfusion of TEA while no change was seen in TTX perfusion group.The results indicate that potassium ionic channels develop slower in stages Ⅱ and Ⅳ, faster in stages Ⅰ and Ⅲ and mature by the end of stage Ⅳ.
