Anterior-posterior (AP) and dorsal-ventral (DV) motility maps. (A) As in Figure 1C, QSTMap of the averaged AP component of the velocity vector field as a function of the distance down the gut. The color axis represents the velocities, with positive and negative values denoting posterior and anterior movement, respectively. (B) QSTMap of the averaged DV component of the velocity vector field as a function of the distance down the gut, from the same image data as (A). The color axis represents the velocities, with positive and negative values denoting outward and inward movement relative to the intestinal midline, respectively. (C) Gut motility velocities as a function of time at a fixed position along the gut, indicated by the red boxes in A and B, for both the AP and DV components of the averaged vector field. Both longitudinal and transverse motions are correlated, with the DV component lagging the AP component by a few seconds.