Ultrastructural analysis of basal neuroepithelial cells in dysraphic mice

Ultrastructure of the Neural Basal Lamina in Loop-Tail Mice

“…It is of interest that with conventional fixation for electron microscopy, the neuroepithelium in the dys raphic loop-tail embryos exhibits 'light' and 'dark' cells scattered randomly along the basal aspect of the neural tube [Wilson, 1985]. In the current study, neither TA fixation nor the RR procedure produced these varia tions in electron density of the basal cytoplasm.…”

“…During abnormal development of the loop-tail mouse, an increase in ran dom interruptions has been noted in the neural basal lamina of dysraphic embryos fixed conventionally at 9 days of gestation [Wilson, 1985]. The results of the cur rent study indicate that even the intact portions of the abnormal basal lamina show structural alterations.…”

“…Loop-tail mice are characterized by extensive neural dysraphism in the homozygous condition [Strong and Hollander, 1949;Stein and Rudin, 1953;Stein and Mackensen, 1957;Stein et al, I960], With conventional fixation at the electron microscopic level, the neural basal lamina in 9-day abnormal loop-tail embryos shows an increased incidence of gaps or discontinuities, where by direct contact may occur between neuroepithelial cells and cytoplasmic processes from mesenchymal cells and notochordal cells [Wilson, 1985]. Studies on the basal laminae of various embryonic, postnatal, and adult organs have shown that treatment of tissues with compounds such as tannic acid (TA) and ruthenium red (RR) can reveal additional ultrastructural features of the basal lamina which are not detectable with routine techniques [Trelstad et al, 1974;Hay and Meier, 1974;Cohn et al, 1977;Hay, 1978;Lofberg and Ahlfors, 1978;Gordon and Bernfield, 1980;Williams and Daniel, 1983], In view of the putative role which the basal lamina may play during normal morphogenesis as well as during tissue repair [Vracko, 1982;Reale, 1984;Bern field et al, 1984;Linsenmayer et al.…”