a, Schematic of water-maze apparatus (adapted from ref. 22; see Supplementary Information). Mice were trained to associate striped grating with escape from water by a hidden platform. An animal ‘passes’ a trial by crossing the red line (decision point) on the side of the divider with the striped grating. b, Pass rate of Nrl-GFP-treated (black), sham-injected (dark grey) and non-injected (mid grey) Gnat1−/− and non-injected wild-type (light grey) mice. Nrl-GFP-treated animals with a pass-rate of at least 70% are shown in green throughout. Mouse numbers in red refer to mice shown in Supplementary Movie. c, Average performance rate of all groups. d, Visual acuity and e, contrast sensitivity measurements for responders from Nrl-GFP-treated (green) and wild-type (light grey) groups. f, Swim-time latencies (time-to-platform) for all (light grey) and correct choice-only (dark grey) trials. g, Ability to solve water-maze task plotted against integrated Nrl-GFP photoreceptor number. h, Examples of integration in animals that successfully (top; Nrl-GFP-treated, number 6) or unsuccessfully (bottom; Nrl-GFP-treated, number 5) solved the task, as indicated in g (circled, red). These panel images are cropped from montages composed of multiple smaller images manually assembled across overlapping areas. Scale bar, 100 µm. i–k, Pass rate (i), visual acuity (j) and contrast sensitivity (k) for Nrl-GFP-treated (light grey bars) and sham-injected (dark grey bars) Gnat1−/− mice before and after transplantation under photopic conditions. Means ± s.e.m.; ANOVA; n, number of animals.
