La migración neuroblástica: aspectos embriológicos y mecanismos

Resumen

The gene LIS1, defective in lissencephaly type 1 of Miller and Dieker, is expressed in the neuroepithelial cells, in the ependyma and the Cajal-Retzius neurons. These transitory fetal cells are the first neurons of the cerebral cortex. Most of the neurons of the cortical plate arrive by means of glial radial cells which guide them towards their destination. Cell adhesion molecules from the neuroblasts themselves, the glial radial cell, the extracellular matrix and perhaps the ependymal cells are important in adhering the neuroblasts to the glial radial cells. Genetic deficiency of these molecules results in defective migration. The mechanism of cellular movement is still not fully understood. Disorders of migration may also be induced by non-genetic factors, such as infarcts or other lesions which damage or destroy the glial radial fibres during the fetal period.