DEVELOPMENT OF EMBRYONIC RHOMBENCEPHALON TRANSPLANTED INTO ADULT-RAT CEREBELLUM

The Present experiment on neural transplantation is an attempt to inve stigate the mechanisms of development of embryonic neural tissues whic h have been grafted into the brain of adult animals. The main objectiv es of the present study are to find out whether grafted embryonic neur al cells can survive, grow and differentiate into specific cell or neu ronal types, contact with afferent fibers and integrate into host brai n environment, especially when the host brain has been freshly lesione d. Embryonic rhombencephalic cell suspension isolated from E15 stage r at embryos were injected into the cerebellar vermis of adult rats whic h had been lesioned with Kainic acid (KA) one week before the transpla ntation. Histological observations were performed at 2, 3 and 4 weeks after transplantation. The results indicated that grafted neural cells did not only grow and differentiate into Purkinje cells (PC's) like t hose in the adult cerebellar cortex, but also to a certain extent inte grated into damaged host brain, to replace the lost neurons. The prese nt evidence indicates that, under freshly lesioned conditions, the hos t brain may be receptive to the neural grafted cells and provide a suf ficiently neuronotrophic environment for further development.