Figure 5.
Spectral analysis of body wall movements and fictive behavior. A. Analysis of body wall movements. Left column: Contractions and relaxations in left (black) and right (gray) dorsal areas in the segment with attached ganglion (low-pass filtered). Second column: Power spectrum of the contractions (DC baseline subtracted). Third and fourth columns: spectrogram of contractions in the left and right dorsal areas (high-pass filtered with f0 = 0.5/min). The “ci-5” data (top row) and “ci-6” data (bottom row) are from separate experiments. B. Analysis of fictive behavior of a chain of ganglia M3–M8 bathed in conopressin. Left column: firing rate in left (black) and right (gray) DP1 nerves of ganglia M4 through M7 (top to bottom; low-pass filtered). Second column: Power spectrum of the firing rate (DC baseline subtracted). Third and fourth columns: spectrogram of firing rates in the left and right DP1 nerves (high-pass filtered with f0 = 0.5/min). All rows based on simultaneously recorded data, but note the different vertical scales for each row. C. Spectral power in the frequency band corresponding to the 5-minute rhythm (f = 0.15–0.25/min) in saline (white) and conopressin (gray). Data from 18, 26, 28, 16 nerves from M4, M5, M6, M7 respectively. *: p<0.05, two-tailed t-test. D. Real part of the coherence between left and right nerve activity in this band. Data from 9, 13, 14, 8 nerve pairs from M4, M5, M6, M7 respectively. ***: p<0.001. E. Spectral power in the frequency band corresponding to the bursts (f = 1–10/min). Statistics as for C; **: p<0.01. Analogous data from nerve cords bathed in saline and hirudotocin are presented in Supplemental Figure S3.