Fig. 2.

VSD imaging of V1 responses to the real motion stimuli. (A and B, Upper) Stimulus sequence consisting of apparent motion quartet before (four cycles, only one shown) and after (six cycles, one shown) the real motion stimuli (one cycle) along path A and path B, respectively. (Lower) Example of VSD signals in response to the real motion stimulation along path A and path B, respectively. Each colorgram represents average signal over 30 ms (total time of one sweep of real motion: 180 ms), color coded with scale (Right). Black and white squares represent the region of maximal VSD signals evoked by the four flash dots illustrated in Fig. 1. (Scale bar, 500 μm.) (C) Difference of VSD responses (“Δ response”) to the real motion along path A and path B for the example recording shown in A and B. Red and blue arrowheads mark the cortical regions representing path A and path B, respectively. Black contour lines depict cortical regions with strong positive Δ responses. (D) Average Δ response from all of the experiments (on 19 mice). Before averaging, the spatial patterns of cortical responses measured in each mouse were transformed (see text).