Fig. 3

Pretectal binocular selective neurons processing visual stimuli presented from below. a The visual stimulus was presented from below the animal, while calcium activity was recorded from above. b Top: Ten binocular stimulus phases were repeated 3 to 10 times. The black arrowheads indicate the gratings’ moving directions. Bottom: normalized ΔF/F calcium responses for three examples, forward-selective, sideward-selective, and forward-and-sideward-selective neurons. White bars indicate the gratings’ moving directions for the corresponding eyes (colored circles); black circles represent eyes when stationary gratings were presented. c Neuronal response types were classified based on the calcium activity during the ten stimulation phases (y-axis, black: active). The width in the x-axis corresponds to the cell number for each response type. Response types are ordered according to frequency. d Response profiles of the eight most frequent response types (Additional file 3: Figure S3 for the mirror-symmetrical response types). Response types labeled “non-selective” are active for more than one stimulus phase. Response types labeled “binocular” are influenced by stimulus motion presented to either eye. e Grouped and averaged response profiles of all neurons (leftward or rightward) that are sideward-selective, when only the first 8 stimulus phases are considered, corresponding to response type “S” in the previous study [9]. The first four rows show all possible response combinations for S type cells (including all 10 — not just 8 — stimulus phases) and the last row shows the weighted average of all S type neurons. The cell numbers correspond to the sum of S type cells and the mirror-symmetrical S′ type cells. Note that the response type exclusively active for leftward motion (S w/o FW w/o BW, first row) cannot be detected when all responses are merged together (fifth row). In the study by Naumann et al., only this fifth merged response type has been reported