Enhanced axonal growth from fetal human bcl-2 transgenic mouse dopamine neurons transplanted to the adult rat striatum

Embryonic neurons transplanted to the adult CNS extend axons only for a dev elopmentally defined period. There are certain intercellular factors that c ontrol the axonal extension, one of which may be the expression of the bcl- 2 protein. In this study, mts with complete striatal dopamine fiber denerva tion received embryonic day 14 mouse ventral mesencephalon cells overexpres sing human bcl-2 or control wild-type ventral mesencephalon cells. All rats were treated with cyclosporine to prevent rejection and the surviving graf ts were analyzed for cell survival and outgrowth of dopaminergic fibers. Th e results demonstrate that bcl-2 overexpression does not enhance neuronal g raft survival. However, the bcl-2 overexpressing neurons had a higher numbe r of dopaminergic fibers that grew longer distances. These results show that overexpression of bcl-2 can result in longer distan ce axonal growth of transplanted fetal dopaminergic neurons and that geneti c modification of embryonic donor cells may enhance their ability to reinne rvate a neuronal target territory. (C) 2001 IBRO. Published by Elsevier Sci ence Ltd. All rights reserved.