2-Deoxyglucose autoradiographic evidence that fetal substantia nigra grafts exert contralateral effects in 6-hydroxydopamine-lesioned animals who recover motor asymmetries

Fetal substantia nigra grafts decrease turning behavior induced by dopaminergic agonists in rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal system. The purpose of this study was to determine, through the [ 14C]2-Deoxyglucose autoradiographic method, whether substantia nigra grafts have an effect on efferent striatal nuclei and other related structures. The results showed an unexpected enhancement of metabolic activity in the substantia nigra pars reticulata and striatum on the side contralateral to the lesion and a bilateral enhancement in the thalamus and frontoparietal cortex, in rats bearing fetal substantia nigra grafts. The results are discussed in terms of the possibility that recovery of turning behavior may in part be caused by an increased activity of the striatum contralateral to the grafted side.