[Vimentin and neuroepithelial cell differentiation in the spinal cord of chick embryos: an immunohistochemical study]

Using vimentin immunohistochemical staining, the differentiation processes of neuroepithelium in the neural tube were examined in chick embryos from stages 8 through 28. At an early stage of the neural groove, stage 8, no morphological differences could be found among the neuroepithelial cells, but vimentin staining allowed us to identify four different regions in the groove wall. The epithelial cells in the ventral wall exhibited moderate staining of vimentin, and vimentin was detected in the basal and middle cytoplasmic areas. A weak staining limited to the basal cytoplasm was observed in the dorsal wall. In contrast, epithelial cells in the median hinge region and in the lateral edge of the neural groove had little vimentin. On the basis of this vimentin staining, four similar regions could also be observed in the neuroepithelium of the neural tube at stage 12; the ventral wall, dorsal wall, floor plate and roof plate. Prior to the morphological changes in the neuroepithelial cells, vimentin expression showed dramatic changes, and our immunohistochemical data suggest that cell differentiation into motor areas and sensory areas starts at an early stage of the neural groove.