The reactions of different sections of human embryonic neuroepithelium to damage to the ventricular surface during explantation

: Fragments of different regions of brain, spinal cord and retina obtained from 6 up to 7 wk human embryos were placed into media 199. On 24th hr of cultivation multiple invaginations developed in the explant ventricular surface as a response to its damage while preparing to explantation. Maturity extent of neural and glial elements was not essential to invagination intensity. Fragments of tectum and retina that are characterised by permanent shape of ventricular surface displayed minimal activity. These data suggest that the reaction considered reflects a property of neuroepithelial cells that constitutes an important factor in normal brain morphogenesis.