Dorsolateral regions of embryonic human neocortex at 9-11 weeks of development were transplanted into the eye anterior chamber of rat. Significant changes, leading to the complete destruction of the original cytoarchitectonies occured during the first three days. Intensive neuroblast degeneration in cortical and interstitial zones as well as decrease of mitotically deviding cell numder were observed 3-6 hours after the transplantation. Neuroepithelial cells form rosettes in ventricular zone by the end of the first day. Rosettes turned into the centres of proliferation, mitotic activity restored to the initial level. Cells migrated out of the rosettes in radial directions. By the end of the third day almost all the cells in cortical and interstitial zones degenerated, transplant was almost completely represented by the ventricular zone cells. Number of mitotic figures exceeded the initial level almost three times, transplant was enlarged, its blood supply was absent. Since the 4-th day mitotic activity decreased, transplant underwent lymphoid infiltration and its complete destruction occured by the end of the second week.