Croll R P, Voronezhskaya E E
Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada,
Dev Biol. 1996 Jan 10;173(1):344-7. doi: 10.1006/dbio.1996.0028.
The first elements of the nervous system of pond snails appear in the very early veliger stage of development at much earlier times than any previously described neurons. The first three cells are reactive to antibodies raised against both the neuropeptide FMRFamide and tubulin and their somata are located posteriorly within the embryo, not in anterior regions, as would be consistent with current concepts of gastropod neurogenesis. Furthermore, the extensive, anteriorly directed fibers from these cells appear to form a scaffold upon which the central ganglia and interconnecting pathways later develop. These findings challenge current thoughts on the origins of early embryonic neurons and on possible inductive cues and mechanisms of axonal navigation important in the development of the molluscan nervous system.
池塘蜗牛神经系统的最初元素出现在发育的极早期面盘幼虫阶段，比之前描述的任何神经元都要早得多。最初的三个细胞对针对神经肽FMRF酰胺和微管蛋白产生的抗体有反应，它们的胞体位于胚胎后部，而非前部区域，这与腹足纲神经发生的当前概念相符。此外，来自这些细胞的广泛的向前延伸的纤维似乎形成了一个支架，中枢神经节和相互连接的通路随后在这个支架上发育。这些发现挑战了目前关于早期胚胎神经元起源以及对软体动物神经系统发育重要的轴突导航可能的诱导信号和机制的看法。
