Peculiarities of spinal cord segments structural organization in human fetuses with anencephaly of 17–18 weeks of intrauterine development

Abstract

The principles of the human spinal cord development constitute the basis for understanding of appearance of congenital abnormalities of the CNS development, which make 7 % of the total number of malformations in the embryonic period of human’s development.Purpose – to find out the cytoarchitectonic structure of the spinal cord segments of human fetuses with anencephaly, their morphometric parameters and the degree of the proliferation of neural stem cells.Materials and methods – anatomical and histological, immunohistochemical and morphometric research was carried out related to the spinal cord of 4 human fetuses with anencephaly of the gestational period of 17–18 weeks.Results. The length of the spinal cord of 17–18 weeks anencephalic fetuses corresponds to the length of human fetuses without malformations of 11–12 weeks, the rest macrometric parameters – 8–9 weeks. The largest area of grey matter was that of segments at the level of lumbosacral and cervical enlargements, the least one at the level of thoracic segments. The specific gravity of neuroepithelium in the grey matter of cervical, thoracic, lumbar and sacral segments was 0.4, 0.1, 0.6, 1.6 % respectively. The expression of the proliferation protein in the spinal cord neuroepithelium segments of anencephalic fetuses is approaching 0 %. However, in the ventral horns near the location of neural complexes single mitoses of glial cells occur. In quantitative terms, in the ventral horns 1.5 % of glial cells reacted, while in the dorsal ones – 0.6 %. The expression of vimentin in the mantle and marginal layers is poor. On the border between the ventral and dorsal horns an insignificant number of fibers have a radial direction. Moderate expression of synaptophysin was observed in the marginal layer, except for cuneate fasciculi where the relatively weak expression has been established, which testifies to the insufficient myelination of the conduction tracts fibers.Conclusions. Macro- and morphometric parameters of the spinal cord of human fetuses with 17–18 week anencephaly point out to the significant retardation in development. Numerous disorders in the structural organization of both grey matter and white matter have been found out. The proliferation of neural stem cells in neuroepithelium is approaching 0 %.