Veluman A A
Neirofiziologiia. 1985;17(1):70-7.
Antidromic action potentials of chick embryonic hindlimb motoneurons were studied intracellularly in the isolated perfused spinal cord during the second half of the incubation period. Although the microelectrode penetration produced damage of most of cells, some of them could restore their conditions. The amplitude and time-to-peak of action potentials and the presence of components reflecting activation of the initial axon segment and somadendritic membrane as well as values of resting potentials did not show any age dependence in these cells from the 11th to 18th day of the embryonic development and were similar to those in adult birds and mammals while impulse conduction velocities of motor axons increased from 0.3-0.5 m/s in 10-day embryos to 2-4 m/s in 18-day embryos. These results do not support the hypothesis based on the study of newborn mammalian neurons in situ, which points to rather late postnatal maturation of action potential mechanisms. The early onset and maturation of action potentials in the chick embryonic motoneurons is in agreement both with the phylogenetic anciency of this mechanism and with the recent studies performed on different isolated preparations of developing CNS of warm-blooded animals.
在孵化期的后半段，对分离灌注的脊髓中鸡胚后肢运动神经元的逆行动作电位进行了细胞内研究。尽管微电极穿刺对大多数细胞造成了损伤，但其中一些细胞能够恢复其状态。在胚胎发育的第11天至18天，这些细胞的动作电位幅度、峰值时间以及反映初始轴突节段和胞体树突膜激活的成分的存在情况，以及静息电位值均未表现出任何年龄依赖性，并且与成年鸟类和哺乳动物的情况相似，而运动轴突的冲动传导速度从10日龄胚胎时的0.3 - 0.5米/秒增加到18日龄胚胎时的2 - 4米/秒。这些结果不支持基于对新生哺乳动物神经元原位研究得出的假设，该假设指出动作电位机制在出生后相当晚才成熟。鸡胚运动神经元动作电位的早期出现和成熟，既与该机制的系统发育古老性一致，也与最近对温血动物发育中的中枢神经系统不同离体标本所进行的研究一致。
