(A) Experimental timeline. Animals were monocularly deprived for 7 days, or were not subjected to deprivation. In some cases mice were deprived for only 1 or 3-4 days. P: postnatal day. (B) Whole brain view in brightfield (left) and fluorescence (right) showing extent of archaerhodopsin-GFP (Arch-GFP) expression. Dotted lines indicate rough outline of V1, with binocular region marked separately. (C) Co-expression of Arch-GFP in parvalbumin- (PV)-, somatostatin (SST)- and vasoactive intestinal peptide- (VIP)-cre mice with the corresponding interneuron markers. Scale bar = 50 μm (D) Percentage of neurons positive for PV (79%), SST (94%) or VIP (92%) co-expressing Arch (left) and percentage of Arch expressing neurons co-expressing PV (97%), SST (91%) or VIP (95%) (right).