were injected with AAV DIO-Girk2a-eYFP or AAV DIO-eYFP, as described above, and midbrain slices were prepared for whole-cell patch-clamp recordings (Figure 6A,B). As expected, mean IBaclofen currents were smaller in SNX27DA KO mice injected with AAV DIO-eYFP, 80.2 ± 16.9 pA, n=8 (Figure 6B). Remarkably, IBaclofen significantly increased by 3-fold in DA neurons of SNX27DA KO mice injected with AAV DIO GIRK2a-eYFP, 240.9 ± 50.8 pA, n=8 (Figure 6B). Moreover, GABABR-dependent inhibition of action potential firing was restored to that observed in wild-type neurons (Figure 6C,D). Taken together, these experiments suggest that SNX27 is required for forward trafficking and/or maintenance of GIRK2c/GIRK3 channels on the plasma membrane in DA neurons and is important for controlling the excitability of DA neurons.
