Movie 1

The effect of neuronal blockade and blockade of interstitial cells of Cajal on in vivo motility patterns in the proximal intestine of an individual shorthorn sculpin (Myoxocephalus scorpius). The movie depicts gastrointestinal motility patterns from a section of exteriorized intestine from an individual shorthorn sculpin during control conditons (top panel), neuronal blockade (middle panel) and blockade of interstial cells of Cajal (ICC, bottom panel). The exteriorized section of intestine consists of the proximal intestine and a portion of the middle intestine. The proximal intestine begins ~5 mm posterior of the pyloric caeca (bottom left) to the beginning of the middle intestine (section where the intestine loops around the pin). The spatio-temporal maps on the right hand side of the respective video panels were constructed from the section of the proximal intestine. The predominant rhythmic motility patterns in the proximal intestine of an individual shorthorn sculpin under control conditions are the slow anally-propagating contractions (i.e. prolonged, circular muscle contractions that slowly propagate in an anal direction, from bottom left to bottom right) and ‘ripples’ (i.e. rhythmic, high frequency, short duration, shallow circular muscle contractions primarily propagating in an oral direction over relatively small distances). Neurogenic blockade (1 μM TTX) did not abolish the slow anally-propagating contractions or ‘ripples’, but altered their frequency and amplitude, whereas subsequent blockade of ICC with benzbromarone (100 μM) significantly reduced or abolished these motility patterns.