Fig. 3: Responses of ON bipolar cells to light steps in varying size spots.

a Individual response traces for different bipolar cell types to square-wave modulated spots ranging from 20 to 800 μm in size. Each spot is presented at full brightness for 1.5 s following the background intensity, then at full darkness for an additional 1.5 s. The dashed line indicates a baseline, calculated as the average for 200 ms before the stimulus onset. Mean responses are represented by shaded areas, with the variation indicated by ±SEM. Different cell types are color-coded: BC5o (n = 7), BC5i (n = 7), BC5t (n = 5), XBC (n = 8), BC6 (n = 6), BC7 (n = 9), BC8/9 (n = 5). Each ‘n’ represents an individual cell from a separate animal. b Summary response plot derived from (a). Columns represent distinct time points, while rows correspond to individual tested spot sizes. The gradient colors, as specified at the top, denote the response amplitude. c Top: Summary data illustrating that surround strength primarily varies in the lower block (Kruskal-Wallis one-way ANOVA, p < 0.0081, χ² = 9.64, η² = 0.48, df = 2) as opposed to the upper block (Kruskal-Wallis one-way ANOVA, p = 0.49, χ² = 2.4, η² = 0.089, df = 2). The calculation for surround strength involves comparing responses to spots of receptive field center (C) and the surround (S). Bottom: Transience variation is evident in the upper block (Kruskal-Wallis one-wave ANOVA, p < 0.001, χ² = 21.6, η² = 0.8, df = 3) but not significantly in the lower block (Kruskal-Wallis one-wave ANOVA, p = 0.46, χ² = 1.5, η² = 0.079, df = 2). Transience is calculated using early (E: 0.2–0.7 s after light onset) and late (L: 1.2–1.7 s after light onset) light responses. Sample size are identical to (a). d Cumulative distributions of differences in surround strength (top, Kolmogorov-Smirnov test, p < 0.001, d = 0.32) and response transience (bottom, Kolmogorov-Smirnov test, p < 0.001, d = 0.28) between different-type ON bipolar cell pairs in the upper block (cyan) and lower blocks (magenta). e Distance metric (expressed as \(1-{correlation\; coefficient}\)) for each pair of bipolar cell types. Statistical significance in the upper triangle is denoted by asterisks (* p < 0.05, ** p < 0.01, *** p < 0.001). Two-sided permutation tests were performed, and their p-values were adjusted for multiple testing by controlling the false discovery rate (FDR) at a threshold of <0.05. f Leave-one-out classification tests based on functional similarity are highlighted in light brown font, whereas those incorporating depth information are in black. g Details the corresponding classification errors. With the maximum probability approach, each test cell is assigned one of the seven possible types, yielding an expected chance level of 14.3%. g Classification probabilities for each bipolar cell type. Rows represent the test cell under consideration, while columns indicate classification outcomes. Diagonal entries reflect correct classifications, with other areas indicating misclassifications. Source data for this figure are provided as a Source Data file.