EFFECT OF FETAL STRIATAL AND ASTROCYTE TRANSPLANTS INTO UNILATERAL EXCITOTOXIN-LESIONED STRIATUM

Studies have suggested that neurotrophic mechanisms may underlie trans plant-induced functional recovery. Astrocytes have been reported to be a source of neurotrophic factors. The present study examined the poss ible role of cultured astrocytes in promoting recovery of apomorphine- induced rotation behavior in rats with unilateral kainic acid (KA) les ions of the striatum. Five weeks after the lesions, one group of rats received fetal striatal tissue (E17) transplants, another group receiv ed transplants of cultured astrocyte suspension, and the remaining rat s received sham transplants and served as controls. Apomorphine-induce d rotation behavior was tested 4 weeks after the KA lesions, and 5 and 10 weeks following the transplantation. The KA-induced rotation behav ior was reduced by the striatal transplants but not by the cultured as trocyte transplants 5 and 10 weeks following the transplantation. Hist ochemical analysis indicated that the striatal transplants had survive d and grown and contained neurons and glia with similar morphology to those in the host brain. Immunocytochemical analysis of the astrocyte transplant sites revealed heavy glial fibrillary acidic protein and OX -42 staining in the transplant areas, suggesting that the transplanted astrocytes may have survived in the host brain. Although fetal striat al transplants can ameliorate apomorphine-induced rotation behavior, t ransplants of astrocytes alone may not be sufficient to reverse the fu nctional deficits produced by KA lesions.