End inhibition in VS cells—population analysis. a, Membrane potential responses (black) and calcium responses in the dendrites (blue) and axon terminals (red) of VS cells to gratings of varying horizontal extent drifting in the preferred direction (means with 95% bootstrap confidence intervals, n = 13 cells). Normalized membrane potential for V_m traces, normalized ΔF/F for calcium-imaging traces for all panels. b, Calcium responses in dendrites and axon terminals as in a, compared with the arithmetic summation prediction of dendritic responses constructed from the receptive field. c, Responses to gratings of varying vertical extent drifting in the preferred direction. Gratings were either 10° or 20° wide, responses from each cell normalized to longest 10° grating. d, The effect of adding a laterally positioned 20° grating on the calcium responses to a grating in the center of the dendritic receptive field (n = 10 cells). Solid lines are lateral displacements toward the center of the visual field, broken lines toward the periphery. ΔF/F responses normalized to responses to central grating (see Results).