L-DOPA-induced increase in TH-immunoreactive striatal neurons in parkinsonian mice: Insights into regulation and function

► Chronic l-DOPA increases striatal TH neurons in a dose-dependent way in parkinsonian mice. ► l-DOPA induction of TH neurons in lesioned striatum requires dopamine D1 receptors and ERK activation. ► Tight correlation between striatal TH-ir neurons, recovery of DA overflow and contralateral forelimb use. ► Induction of striatal TH neurons by l-DOPA is independent of Pixt3 expression. ► Olfactory bulb grafts also induce TH neurons in denervated striatum.