The transgene targeted ot the locus contains a splice acceptor flanked puro cassette, CAG promoter, floxed stop cassette, FRT-flanked stop cassette, the channelrhodopsin-2 from the green alga Chlamydomonas reinhardtii modified to contain a C128A substitution (COP4*C128A), and a woodchuck hepatitis virus post-transcriptional regulatory element (WPRE).