IN-VIVO PET IMAGING IN RAT OF DOPAMINE TERMINALS REVEALS FUNCTIONAL NEURAL TRANSPLANTS

Positron emission tomography (PET) and carbon-11-labeled 2B-carbometho xy-3B-(4-fluorophenyl) tropane (C-11-CFT or (11)-WIN 35,428) were used as molecular markers for striatal presynaptic dopamine (DA) transport ers in a unilateral Parkinson's disease rat neurotransplantation model . In the lesioned striatum, the binding ratio measured by the DA presy naptic marker was reduced to 15% to 35% of the intact side (or unopera ted control). After grafting with non-DA cells (from dorsal mesencepha lon), the DA binding ratio remained reduced to levels observed before transplantation and rats showed no behavioral recovery. In contrast, a fter DA neuronal transplantation, behavioral recovery occurred only af ter the C-11-CFT binding ratio had increased to 75% to 85% of the inta ct side. This study provides direct in vivo evidence for the dopaminer gic molecular basis of functional recovery in the lesioned nigrostriat al system after neural transplantation.