Egid K, Lnenicka G A
Department of Biological Sciences, State University of New York, Albany 12222.
J Neurobiol. 1993 Aug;24(8):1111-20. doi: 10.1002/neu.480240809.
An explant culture system is described that allows examination of axonal growth from the tonically and phasically active motoneurons of the abdominal nerve cord of the crayfish. In this preparation, growth occurs from the cut end of the axon while the remainder of the motoneuron is undisturbed. In vitro growth from the branches of the third roots, which contain the axons from the tonic and phasic motoneurons of abdominal ganglia one through four, was verified as axonal by retrograde labeling of axons and neuronal somata within the nerve cord. Growth from the axons of phasic and tonic cells was observed as early as 24 h after plating and continued for an additional 7-10 days. The morphology and growth rates of the motor terminals differed between the tonic and phasic axons. The phasic axons grew significantly faster and branched more often than did the tonic motor axons. These differences in growth may be related to differences in motoneuron size or, may result from differences in electrical activity. Tonic motoneurons show spontaneous impulse activity for up to 6 days in culture, whereas phasic motoneurons show no spontaneous impulse activity. In addition, the differences in growth may be related to the morphological differences in tonic and phasic motor terminals observed in situ.
本文描述了一种外植体培养系统，该系统可用于研究小龙虾腹神经索中紧张性和阶段性活动的运动神经元的轴突生长。在这种制备方法中，轴突生长发生在轴突的切断端，而运动神经元的其余部分不受干扰。通过对神经索内的轴突和神经元胞体进行逆行标记，证实了来自第三根分支的体外生长，这些分支包含来自第一至第四腹神经节的紧张性和阶段性运动神经元的轴突。早在接种后24小时就观察到了紧张性和阶段性细胞轴突的生长，并持续了另外7 - 10天。紧张性和阶段性轴突的运动终末的形态和生长速率有所不同。阶段性轴突的生长明显更快，分支也比紧张性运动轴突更频繁。这些生长差异可能与运动神经元大小的差异有关，或者可能是由电活动的差异导致的。紧张性运动神经元在培养中可显示长达6天的自发冲动活动，而阶段性运动神经元则不显示自发冲动活动。此外，生长差异可能与在原位观察到的紧张性和阶段性运动终末的形态差异有关。
