Epperlein H H, Krotoski D, Halfter W, Frey A
Anatomisches Institut, Universtät Freiburg, Federal Republic of Germany.
Anat Embryol (Berl). 1990;182(1):53-67. doi: 10.1007/BF00187527.
In Xenopus, we investigated the origin of enteric neurones and their distribution in relation to the extracellular matrix (ECM) components, fibronectin (FN) and tenascin (TN). Enteric neurone precursor cells originate from the anterior trunk neural crest (NC). They migrate along the ventromedial NC pathway (between somites and neural tube/notochord) into the primitive gut (via the dorsal mesentery/lateral plate mesoderm) where they differentiate into enteric neurones. NC cells were identified during their migration and in the gut using the X. laevis - X. borealis nuclear marker system. The neuronal character of NC cells in the gut could be demonstrated immunohistochemically with a monoclonal antibody against the HNK-1 epitope. This antibody is superior to N-CAM and neurofilament antibodies which proved insufficient in Xenopus. In early tadpoles (stage 45), enteric neurones occurred frequently in the mesenchymal lining of the oesophagus, either singly or in groups of two to three cells. In more distal portions of the digestive tract, enteric neurones were rarely found. In metamorphosing tadpoles (stage 62/63), enteric neurones were scattered singly beneath the mucosa, or formed small aggregates between the inner and outer muscle layer throughout the length of the digestive tract. The neurones occurred in positions corresponding to the myenteric and submucosal plexus of higher vertebrates. The distribution of enteric neurones was studied in relation to fibronectin (FN) and tenascin (TN), glycoproteins of the ECM, which support (FN) and inhibit (TN) amphibian NC cell migration. Using immunohistochemistry, FN was found during NC cell migration in ECM spaces along the ventromedial pathway, and in the gut between the mucosa and the muscle layers, where it would be able to support adhesion and migration of NC cells. TN, in contrast, appeared much later than FN, both in the dorsal trunk and also ventrally, in the gut. In older tadpoles, TN was present in the mesenchyme and muscle layers of the digestive tract, where it might have an inhibiting influence on the migration of enteric neurones within the gut wall.
在非洲爪蟾中，我们研究了肠神经元的起源及其与细胞外基质（ECM）成分、纤连蛋白（FN）和腱生蛋白（TN）相关的分布情况。肠神经元前体细胞起源于躯干前部神经嵴（NC）。它们沿着腹内侧神经嵴途径（在体节与神经管/脊索之间）迁移到原始肠道（通过背系膜/侧板中胚层），并在那里分化为肠神经元。在迁移过程中以及在肠道中，利用非洲爪蟾 - 北美爪蟾核标记系统鉴定出了神经嵴细胞。肠道中神经嵴细胞的神经元特性可用针对HNK - 1表位的单克隆抗体通过免疫组织化学方法予以证实。该抗体优于N - CAM和神经丝抗体，在非洲爪蟾中后者已被证明并不充分。在早期蝌蚪（45期），肠神经元频繁出现于食管的间充质内衬中，单个或两三个细胞成群存在。在消化道更靠远端的部分，很少发现肠神经元。在变态期蝌蚪（62/63期），肠神经元单个散在于黏膜下方，或在整个消化道的内、外肌层之间形成小的聚集。这些神经元出现在与高等脊椎动物的肌间神经丛和黏膜下神经丛相对应的位置。研究了肠神经元与纤连蛋白（FN）和腱生蛋白（TN）的分布关系，它们是细胞外基质的糖蛋白，分别支持（FN）和抑制（TN）两栖类神经嵴细胞的迁移。利用免疫组织化学方法发现，在神经嵴细胞沿着腹内侧途径迁移过程中，FN存在于细胞外基质空间中，在肠道的黏膜和肌层之间也有，在那里它能够支持神经嵴细胞的黏附和迁移。相比之下，TN出现的时间比FN晚得多，在背侧躯干以及肠道腹侧均是如此。在较老的蝌蚪中，TN存在于消化道的间充质和肌层中，在那里它可能对肠神经元在肠壁内的迁移具有抑制作用。
