MiniPromoters Ple384 (TH) and Ple388 (PITX3) for targeting midbrain dopaminergic neurons in mice and monkeys.

There is considerable interest in targeting dopaminergic neurons in the substantia nigra compacta (SNc) and ventral tegmental area (VTA) to monitor or modulate their activity in normal and diseased states. The limited availability of selective promoters has hampered progress in non-transgenic animals. Thus, we designed MiniPromoters to target TH-expressing neurons in the midbrain of mice and non-human primates. After screening eight recombinant AAVs encoding MiniPromoters driving EmGFP in mice by intravenous (IV) and intracerebroventricular (ICV) injections, we identified Ple384 (TH) and Ple388 (PITX3), which resulted in robust selective expression in SNc and VTA. These rAAVs were further characterized in rhesus macaques using ICV where both MiniPromoters expressed throughout the SNc, with Ple384 (TH) more widespread than Ple388 (PITX3) in VTA neurons. Both MiniPromoters will be useful for expression of research and gene therapy molecules in midbrain dopaminergic neurons in mice and non-human primates.