SLC6A3 and major depressive disorder: Furthermore, selective knockdown of TRPC6 in the mPFC-projecting VTA DA neurons (virus-retro carrying DIO-Trpc6-shRNA (TRPC6-rcKD) was injected into the mPFC of Slc6a3-Cre male mice) (Figure 8A–C) also conferred the mice with the depression- and anxiety-like behaviors (Figure 8D).