SLC6A3 and infection: Because it has been shown that minute TVA expression is sufficient for infection by ALSV-A (Belanger et al., 1995), we reasoned that DAT-Cre-expressing dopamine neurons in the midbrain which were retrogradely infected by AAV5-FLEX-TVA would express enough TVA for initial rabies infection in a Cre-dependent manner (Figure 1A).