ENHANCEMENT OF GRAFT-SURVIVAL AND SENSORIMOTOR BEHAVIORAL RECOVERY INRATS UNDERGOING TRANSPLANTATION WITH DOPAMINERGIC CELLS EXPOSED TO GLIAL-CELL LINE-DERIVED NEUROTROPHIC FACTOR

Object. The goal of this study was to investigate the ability of fetal dopaminergic neurons to improve complex sen sorimotor behavior. Metho ds. The authors obtained ventral mesencephalic tissue from 14-day-old rat fetuses. The cells were exposed to glial cell line-derived neurotr ophic factor (GDNF) prior to transplantation into rats with unilateral 6-hydroxydopamine lesions of the dopaminergic nigrostriatal pathway. Animals that received 400,000 cells exposed to GDNF demonstrated signi ficant improvement in contralateral forelimb function and showed impro vement in rotational behavior faster than animals that received cells not exposed to GDNF. Increasing the number of implanted cells to 800,0 00 exposed to GDNF did not result in any additional improvement in fun ctional recovery. Conclusions. As neural grafting procedures in the ne rvous system evolve and genetically engineered cells or stem cells rep lace fetal tissue, crucial questions about cell number and trophic reg ulation will need to be addressed. This study demonstrates that grafti ng of 400,000 cells exposed to GDNF before transplantation has a benef icial effect in the restoration of complex sensorimotor behavior.