Figure 3.
Kinematics of a semi-intact body wall during conopressin-induced twisting. A. Frame from a body wall videorecording with anatomical features indicated. Shaded regions are dorsal (D) and ventral (V) areas on the left (l) and right (r) sides of segments M5 and M6 that were used for motion analysis. (For visual clarity, areas 5D(r), 5V(l), 6D(l) and 6V(r) are not indicated on the image, although they were included in the analysis.) B. Temporal pattern of longitudinal elongation and contraction of the dorsal body wall on the left (gray line: area 6D(l)) and right (black line: area 6D(r)) around M6 in a typical “ci-6” recording. Note the alternation between contractions on the left and on the right. C. Same data after low-pass filtering. D. Expanded view of the shaded region in B after high-pass filtering. E. Temporal correlation between the lengths of various regions (patterned shading) of the body wall within a segment (M5: white bars; M6: gray bars). All are with reference to one (“ipsilateral”) dorsal region in the same sgment. Movements were analyzed on the slow time scale, i.e., the low-pass filtered as in C, and significant differences from zero are indicated: *: p<0.05; **: p<0.01; ***: p<0.001 (two tailed t-tests). F. Excerpt from the data shown in B demonstrating that the amplitude of the fast pulses was greater during the contraction phase of the slow rhythm than during its relaxation. G. Correlation between the amplitude of the fast rhythm (cf. B, D) with the simultaneously measured overall length of the same region (analyzed on the slow time scale, cf. C). Number of preparations (in parentheses) applies to E as well. An analogous presentation of the contractile rhythm in the circumferential dimension is presented in Supplemental Figure S1.