Fig. 5: Representative tracings for intraluminal pressure, longitudinal and circular muscle contraction, and droplet discharge.
From: Advancing peristalsis deciphering in mouse small intestine by multi-parameter tracking
a The intraluminal pressure (ILP) tracings showing separation into four phases based on Ps, Ls and/or Lg. Lg trace (blue) is obtained by selecting the mean of each Ls. “Before-phase” (BPhase) started with low Lg and Ls, and both progressively increased by the end of the phase. During BPhase, low amplitude pressure waves were observed, and this phase was followed by a phase with increased Ps, called the “near-phase” or NPhase. The NPhase started with a rapid increase in Ps, and during this period Ls progressively increased and reached a peak or plateau marking the end of the NPhase. The NPhase displayed slightly higher Ps when compared to BPhase. The NPhase preceded the high amplitude Ps in “during-phase” (DPhase). Both, Ls and Lg progressively increased and reached a peak from the beginning of the NPhase. The DPhase is the region of the pressure tracing where the highest amplitude contraction waves were observed and was significantly higher when compared to BPhase and NPhase. The DPhase had the longest duration and was followed by “after-phase” (APhase). At the end of the DPhase, Ps, Pg and Lg returned to the base levels and marked the beginning for the APhase. Duration and amplitude (Ps) for Aphase was significantly lower when compared to DPhase but was comparable to that of BPhase. b Representative tracings for SD. The figure shows a significant increase in longitudinal movements (Lg and Ls) from BPhase to Dphase, during which Ps showed a significant increase. DD occurred in DPhase (blue dot). In APhase, Lg and Ls decreased together with a decrease in Ps and Pg. c Representative tracings for LA. The amplitude of Ps, Pg, Ls and Lg were relatively smaller when compared to SD and LD. Lg and Ls increased from BPhase to DPhase and decreased from DPhase to APhase. DD occurred in APhase (blue dots). d Representative tracings for LD. An increase in Lg was observed from NPhase to DPhase but was significantly lower than SD drops. Duration for LA and LD were significantly higher when compared to SD. The decrease in Lg during the Aphase in LD was significantly lower than that observed in SD drops. DD occurred in DPhase. At the end of APhase Lg decreased to the levels observed in Bphase. DD occurred in DPhase (blue dot). Decrease in Lg in Aphase was observed in all DD groups. e Representative pressure trace showing trend over time. ILP maintained steady levels for up to 40 min and thereafter, ILP decreased significantly. Therefore, all subsequent studies were performed within the first 30 min. f Zoomed view from (e) (20–22 min) showing low and high amplitude pressure waves (Ps) with gross pressure changes (Pg). Pressure tracings show high amplitude waves flanked by small rise and fall in pressure strength. g Zoomed view from (f) (21.02–21.1 min) showing crest, trough, amplitude, and wavelength. h Representative traces showing the diameter changes in proximal (EW1) and distal (EW4) tracker with time. Lower values represent decrease in diameter or circular muscle contraction. i Representative trace showing low and high amplitude oscillations (Ls) along the gross longitudinal muscle contraction (Lg). The Lg tracings recorded using PatternTrax are read from left to right, thereby increased values suggest contraction of longitudinal muscles at the proximal end while decreased values suggest contraction at the distal end.
