Abstract
The migration of immature neurons of the cerebrum is genetically programmed from the primitive neuroepithelium before the end of the final mitotic cycle. The orientation of the mitotic spindle determines when a neuroepithelial cell is ready to start migration and the proportion of major genetic material it is destined to receive. 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.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
