Orozco C B, Smith S A, Epstein C J, Rapoport S I
Brain Res. 1987 Mar;429(1):111-22. doi: 10.1016/0165-3806(87)90144-1.
Dorsal root ganglion (DRG) and spinal cord neurons from normal and trisomy 16 fetal mice, an animal model for human trisomy 21 (Down syndrome), were maintained in primary culture and their electrical membrane properties were compared with intracellular recording techniques. After 3-4 weeks in culture, trisomic DRG neurons had a higher mean resting potential (+10%), a higher specific membrane resistance (+50%) and higher excitability (+17%), a shorter action potential (-22%), higher maximal rates of depolarization (+39%) and of two phases of repolarization (+20% and +10%) and a lower duration (-42%) of the afterhyperpolarization, than did control DRG neurons (P less than 0.05). The duration of the action potential was 2X greater than in control neurons, when external calcium was elevated from 1.2 to 10 mM. Differences in the electrical parameters like those observed in DRG neurons also were found in cultured spinal cord neurons. These results indicate that trisomy 16 in fetal mice alters passive and active electrical membrane properties in DRG and spinal cord neurons, and suggest that some differences are related to differences in calcium currents.
将正常和16三体胎儿小鼠（人类21三体综合征，即唐氏综合征的动物模型）的背根神经节（DRG）和脊髓神经元进行原代培养，并用细胞内记录技术比较它们的电膜特性。培养3 - 4周后，三体DRG神经元的平均静息电位更高（+10%），比膜电阻更高（+50%），兴奋性更高（+17%），动作电位更短（-22%），最大去极化速率更高（+39%），复极化两个阶段的速率更高（+20%和+10%），超极化后电位持续时间更短（-42%），与对照DRG神经元相比差异有统计学意义（P小于0.05）。当细胞外钙浓度从1.2 mM升高到10 mM时，动作电位持续时间比对照神经元长2倍。在培养的脊髓神经元中也发现了与DRG神经元类似的电参数差异。这些结果表明，胎儿小鼠的16三体改变了DRG和脊髓神经元的被动和主动电膜特性，并提示某些差异与钙电流的差异有关。
