The transcription factor BCL11A defines a distinctive subset of dopamine neurons in the developing and adult midbrain

Midbrain dopaminergic (mDA) neurons are diverse in their projection targets, impact on behavior and susceptibility to neurodegeneration. Little is known about the molecular mechanisms that establish this diversity in mDA neurons during development. We find that the transcription factor Bcl11a defines a subset of mDA neurons in the developing and adult murine brain. By combining intersectional labeling and viral-mediated tracing we show that Bcl11a-expressing mDA neurons form a highly specific subcircuit within the dopaminergic system. We demonstrate that Bcl11a-expressing mDA neurons in the substantia nigra (SN) are particularly vulnerable to neurodegeneration in an a-synuclein overexpression model of Parkinson9s disease. Inactivation of Bcl11a in developing mDA neurons results in anatomical changes, deficits in motor learning and a dramatic increase in the susceptibility to a-synucleininduced degeneration in SN-mDA neurons. In summary, we identify an mDA subpopulation with highly distinctive characteristics defined by the expression of the transcription factor Bcl11a already during development.