[Changes in the brain neurons of the recipient around an embryonic nerve tissue transplant].

Ultrastructure of adult neurons (sensomotor cortex) of recipient brain tissue localized in the vicinity of developing embryonic nervous tissue transplant has been studied. Partial dedifferentiation of pyramidal neurons has been revealed four days after the transplantation. The following changes were observed: dispersion and nearly complete absence of granular endoplasmic reticulum: appearance of a multitude of small mitochondria and disappearance of large ones; the presence of a large number of free polysomes; marked clearing of nuclei, and the presence of large nucleoli. No destructive processes in neurons were observed.