Midbrain dopaminergic neurons include many subtypes characterised by their location, connectivity and function. Surprisingly, mechanisms underpinning the specification of A9 neurons (responsible for motor function, including within ventral midbrain (VM) grafts for treating Parkinson’s disease) over adjacent A10, remains largely speculated. We assessed the impact of synaptic targeting on survival, integration, and phenotype acquisition of dopaminergic neurons within VM grafts generated from fetal tissue or human pluripotent stem cells. VM progenitors were grafted into female mice with 6OHDA-lesions of host midbrain dopamine neurons, with some animals also receiving intrastriatal quinolinic acid injections to ablate medium spiny neurons (MSN) – the A9 neuron primary target. While loss of MSNs variably affected graft survival, it significantly reduced striatal yet increased cortical innervation. Consequently, grafts showed reduced A9 and increased A10-specification, with more dopamine neurons failing to matur...