Fig. 8: Effects of tetrodotoxin on spatial coordination of action potentials in colonic smooth muscle.

The plots within this figure have the same interpretation as those in Fig. 3. In this case, the plots pertain to the analysis of smooth muscle electrical activities during maintained colonic distension with a metal rod, over electrode separation distances from 2 mm and 30 mm. Plot a, l This plot contains the raw data for the proximal and distal colons, represented by the red and blue lines, respectively. Plot b, m This plot contains the WCOH (absolute value) between the proximal and distal colons. In contrast to Fig. 3, there is very little coherence at 2 Hz. For the 2 mm recording, there is coherence at ~0.8 Hz, whereas for the 30 mm recording, there is no coherence between 0-4 Hz. Plot c, d, n, o These plots contain the CWT (absolute value) for the proximal colon and distal colon respectively. In contrast to Fig. 3, the highest activity is between 0.8 and 1.2 Hz, not 2 Hz. Plot e, p The red and blue lines are traces of bandpass filtered data (filter limits 0.5 and 3.5 Hz) for the proximal and distal colon respectively. Plot f, g, q, r In both plots, a window (length 3 sec) has been slid over the bandpass filtered data in plots e, p. In each window instance, the likelihood that the data has a particular frequency is calculated; these plots display the log-likelihood. The frequency range for which the likelihood is calculated is given by the y-axis—in these examples from 0.5 to 2.5 Hz. Plot h, s These plots overlay the frequency maximizing the log-likelihood function for the proximal (plots f, q), and distal colon (plots g, r). For the 2 mm recording, the frequencies maximizing the likelihood functions are both ~0.8 Hz, whereas for the 30 mm recording, there is very little consistency in frequency. Plot i, t: In these plots, a window (length 3 sec) has been slid over the bandpass filtered data in plots e, p. In each window instance, the cross correlation between the proximal and distal colons is calculated, which these plots display. In contrast to Fig. 3, there are no periods of high or increased correlation, particularly for the 30 mm recording. Plot j, k, u, v: In these plots, a window (length 3 sec) has been slid over the bandpass filtered data in plot e, p. In each window instance, the auto-correlation function is calculated; plot j, u contains the auto-correlation function for the proximal colon, and plots k, v the auto-correlation function for the distal colon. In contrast to Fig. 3, the auto-correlation functions are not periodic at ~0.5 sec, rather, are weakly periodic between 0.8 and 1.25 sec, which is consistent with the frequency estimates displayed in plot h, s.