Fiber optic placement and location of neurons expressing ChR2-mcherry in experimental cases. A–D, Optical fiber tip placement, and distribution of ChR2-mcherry neurons in VGluT2-ires-Cre^ChR2− (N = 7; A), VGluT2-ires-Cre^ChR2+ (N = 8; B), VGAT-ires-Cre^ChR2− (N = 5; C), and VGAT-ires-Cre^ChR2+ (N = 7; D) mice. Bregma level is identified on the far right.