Figure 6: HS dendrites amplify responses to PD spatiotemporal sequences.

A: Space-time plots of compound global motion stimuli. Local moving dark edges were offset in time and space such that they moved coherently in the preferred direction (“PD sequence”) or stepped backwards along the dendrite in the opposite direction (“ND sequence”). B: Average projection of GCaMP6f signals in an HSN dendrite. C: Spatiotemporal profiles of GCaMP6f signals, measured at one micron intervals within the ROI shown by the white dotted line in B, plotted over time for the single moving edges (edge1, edge2, and edge3 alone) as well as the PD and ND sequences. D,E: GCaMP6f responses, integrated over the entire dendrite and plotted over time for three local moving edges (gray lines), the expected response to sequential presentation of the edges, based on the arithmetic sum of the responses to each individual edge (dashed lines) and the measured responses to the PD sequence (D, green line) and ND sequence (E, magenta line). F: Supralinear summation of responses to PD spatiotemporal sequences of dark and light edges moving at either 27°/s or 54°/s in HS dendrites. G: Linear summation of responses to spatiotemporal sequences in T4/T5 axons terminals. The nonlinearity of the responses is captured using the same metric as in Figure 3. See also Figures S2, S6–8.