A30P α-synuclein impairs dopaminergic fiber regeneration and interacts with L-DOPA replacement in MPTP-treated mice

► A30P mutation of α-synuclein inhibits axonal transport. ► L-DOPA replacement is the most effective therapy to treat Parkinson's disease. ► Effects of α-synuclein and L-DOPA replacement on dopaminergic fiber regeneration were studied. ► A30P α-synuclein inhibits dopaminergic fiber regeneration. ► L-DOPA induces dopaminergic cell and fiber loss in parkinsonian A30P α-synuclein mice.