Barreiro-Iglesias Antón, Villar-Cheda Begoña, Abalo Xesús-Manoel, Anadón Ramón, Rodicio María Celina
Department of Cell Biology and Ecology, Faculty of Biology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Brain Res Bull. 2008 Jan 31;75(1):42-52. doi: 10.1016/j.brainresbull.2007.07.020. Epub 2007 Aug 13.
The development of the early axonal scaffold formed by early-differentiating neurons was studied in a primitive vertebrate (the sea lamprey), by immunohistochemistry against acetylated alpha-tubulin and a cell surface marker (HNK-1 antibodies), to determine the degree of conservation of this process in vertebrate evolution. The medial and dorsolateral longitudinal fascicles were the first longitudinal axonal bundles observed to develop in the neural tube, followed by the tract of the postoptic commissure and the supraoptic tract. Establishment of the first dorso-ventral tracts occurs after the appearance of the tract of the postoptic commissure and the medial longitudinal fascicle, the basal plate longitudinal axonal system. The dorsolateral longitudinal fascicle appears to be equivalent to the "descending tract" of the mesencephalic nucleus of the trigeminal nerve of mouse and birds; the possible homologies between other early scaffold tracts of the sea lamprey and those of other vertebrates are also discussed. In addition, present results suggest the presence of highly conserved brain regions that would allow for early neuronal differentiation and axonal pathfinding in vertebrates, which were probably defined before the divergence of Agnathans and Gnathostomes.
通过针对乙酰化α-微管蛋白和一种细胞表面标志物（HNK-1抗体）进行免疫组织化学，在一种原始脊椎动物（海七鳃鳗）中研究了由早期分化神经元形成的早期轴突支架的发育情况，以确定这一过程在脊椎动物进化中的保守程度。内侧和背外侧纵向束是在神经管中观察到的最早发育的纵向轴突束，其次是视交叉后束和视上束。最早的背腹束在视交叉后束和内侧纵向束（基板纵向轴突系统）出现后建立。背外侧纵向束似乎相当于小鼠和鸟类三叉神经中脑核的“下行束”；还讨论了海七鳃鳗其他早期支架束与其他脊椎动物相应束之间可能的同源性。此外，目前的结果表明存在高度保守的脑区，这些脑区允许脊椎动物进行早期神经元分化和轴突寻路，这些脑区可能在无颌类和有颌类动物分化之前就已确定。
