Department of Anatomy, Semmelweis University, Budapest, Hungary.
J Exp Zool B Mol Dev Evol. 2013 Sep;320(6):351-67. doi: 10.1002/jez.b.22505. Epub 2013 May 2.
In the mature mammalian and avian central nervous systems, neuronal destructions are followed by reactive gliosis, but data on other vertebrates are rather controversial. Mammals and birds belong to different amniote groups (Synapsida and Diapsida, respectively), but exhibit common general features in their glial architecture, mainly the predominance of astrocytes. Two vertebrate groups seem to be in special positions of glial evolution: turtles (Testudiniformes) and skates and rays (Batoidea). The purely ependymoglial system of turtles seems to be the simplest one among the extant amniotes. In skates and rays, true astrocytes are preponderant glial elements, in contrast to the other "anamniotes" (and even to reptiles). We investigated stab wounds by the immunohistochemical detection of GFAP in turtles (Trachemys-formerly Pseudemys-scripta elegans), a skate (Raja clavata) and rays (Dasyatis akajei and Torpedo marmorata). Sharks (Scyliorhinus canicula) as ependymoglia-predominated chondrichthyans, and-for positive controls-rats were also studied. In the elasmobranchs, other astroglial markers: glutamine synthetase and S100 protein were also applied. Neither turtles nor elasmobranchs presented considerable astroglial reactions. Critically surveying the former reports on different vertebrates, these results complete the picture that typical post-lesion reactive gliosis is confined to mammals and birds. Analysis of the astroglial systems from phylogenetic perspective suggests that the capability of forming glial demarcation and scar formation evolved independently in mammals and birds. Predominance of astrocytes is a necessary condition but not sufficient for reactive gliosis. The intense glial reactivity of mammals and birds may be attributed to their complex cerebralization.
在成熟的哺乳动物和鸟类中枢神经系统中，神经元破坏后会发生反应性神经胶质增生，但其他脊椎动物的数据则存在争议。哺乳动物和鸟类属于不同的羊膜动物群（分别为合弓类和蜥形类），但在其神经胶质结构中表现出共同的一般特征，主要是星形胶质细胞占优势。有两个脊椎动物群体似乎在神经胶质进化方面处于特殊位置：海龟（龟鳖目）和鳐鱼和魟鱼（板鳃亚纲）。海龟的纯粹室管膜系统似乎是现存羊膜动物中最简单的系统。在鳐鱼和魟鱼中，真正的星形胶质细胞是主要的神经胶质细胞，与其他“无羊膜动物”（甚至爬行动物）形成对比。我们通过免疫组织化学检测 GFAP 在海龟（原拟龟属-黄喉拟水龟）、鳐鱼（孔鳐）和魟鱼（赤魟和斑点星魟）中研究刺伤。鲨鱼（沙虎鲨）作为以室管膜细胞为主的软骨鱼，以及作为阳性对照的大鼠也进行了研究。在软骨鱼中，还应用了其他星形胶质细胞标志物：谷氨酰胺合成酶和 S100 蛋白。无论是海龟还是软骨鱼，都没有明显的星形胶质细胞反应。批判性地审视以前关于不同脊椎动物的报告，这些结果完善了典型的损伤后反应性神经胶质增生仅限于哺乳动物和鸟类的观点。从系统发育角度分析星形胶质细胞系统表明，形成神经胶质分界和瘢痕形成的能力在哺乳动物和鸟类中是独立进化的。星形胶质细胞的优势是形成反应性神经胶质增生的必要条件，但不是充分条件。哺乳动物和鸟类强烈的神经胶质反应可能归因于其复杂的脑化。
