Glial cell-line derived neurotrophic factor (GDNF) replacement attenuates motor impairments and nigrostriatal dopamine deficits in 12-month-old mice with a partial deletion of GDNF

► We examine the effects of GDNF replacement in mice with a GDNF depletion (Gdnf+/−). ► GDNF restores behavioral and biochemical deficits in Gdnf+/− mice. ► Gdnf+/− mice show altered responses to GDNF treatment compared to wild-type mice. ► Long-term changes in nigrostriatal function are influenced by GDNF expression. ► GDNF treatment reduces oxidative-stress markers in Gdnf+/− mice.