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 This is a brief description of three animations of slow waves propagating through the total intact feline small intestine. The animations are based on the data presented in the above mentioned paper.

General: Because it takes so long for a slow wave to reach the end of the intestine, (4-5 minutes) the speed of the animation has been increased fivefold.

 

Animation 1 (figure 3), duration 1 minute (actual analyzed time 5 minutes):

The small intestine is intact. There is one single pacemaker (flashing green star), located in the duodenum, close to the pyloric region. From this region, rhythmically, slow waves propagate both in the oral and in the aboral direction. The red line indicated in figure 3 is the same as the red wave front in the animation. Below the intestines, electrodes located at four sites display the slow wave frequencies at those sites. As shown in the manuscript, occasionally, slow waves are blocked and drop out. I tried to visualize this by having markers pointing to those slow waves that are going to be blocked. I used the colors green, yellow and red to give an indication of when the actual block is going to happen. If you watch carefully, you can actually see some transient increases in velocities of the following slow waves after some of the blocks.

 

Animation 2 (figure 4), duration 1 minute (actual analyzed time 5 minutes):

This is the same experiment as in animation 1. A string was tied around the intestine (at the location indicated) thereby creating a permanent block. The region oral to the ligature behaves the same as before the ligation but the area distal behaves differently; several pacemakers have emerged (flashing blue stars) at various times and location. The orally propagating slow waves are colored in blue.

 

Animation 3 (figure 11B), durination 20 second (actual time 1 minute):

In this experiment, high calcium was infused in the organ bath close to distal areas to evoke strong contractions. These contractions caused blocks, effectively dividing the small intestine into several regions. Several abnormal pacemakers emerged with retrograde propagation, one of which is located in the most distal region.

Wim Lammers

November 2006

 

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