Image velocimetry and spectral analysis enable quantitative characterization of larval zebrafish gut motility

Abstract

2 Summary StatementWe present a new image analysis technique using image velocimetry and spectral analysis that returns quantitative measures of gut contraction strength, frequency, and wave speed that can be used to study gut motility and other cellular movements. AbstractNormal gut function requires rhythmic and coordinated movements that are affected by developmental processes, physical and chemical stimuli, and many debilitating diseases. The imaging and characterization of gut motility, especially regarding periodic, propagative contractions driving material transport, are therefore critical goals. Whereas previous image analysis approaches have successfully extracted properties related to temporal frequency of motility modes, robust measures of contraction magnitude remain elusive. We developed a new image analysis method based on image velocimetry and spectral analysis that reveals temporal characteristics such as frequency and wave propagation speed, while also providing quantitative measures of the amplitude of gut motions. We validate this approach using several challenges to larval zebrafish, imaged with differential interference contrast microscopy. Both acetylcholine exposure and feeding increase frequency and amplitude of motility. Larvae lacking enteric nervous system gut innervation show the same average motility frequency, but reduced and less variable amplitude compared to wild-types. Our image analysis approach enables insights into gut dynamics in a wide variety of developmental and physiological contexts and can also be extended to analyze other types of cell movements.

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“…This enables investigation of the localization and cross-species dynamics of fluorescently labelled bacterial species as well as GI function such as motility and barrier function. Additionally, the gut is simply cut open, making it possible to remove the microbiota for 16S sequencing 85,86,87 . Zebrafish have a considerable advantage over mammalian models when it comes to GI research because of their external fertilisation, rapid development also early transparency, which make investigating GI function in vivo much simpler.…”

Enteric nervous system modulation of luminal pH modifies the microbial environment to promote intestinal health

“…We showed previously that in zebrafish mutants lacking the ENS due to mutation in the ret gene, a bacterial strain is able to persist that would normally be outcompeted in the presence of intestinal flow forces [38]. Coordinated, ENS-regulated intestinal contractions begin in larval zebrafish at 4 dpf and are robustly established by 6 dpf [40,90]. Here we assayed intestinal transit as a functional readout of these contractions and showed that sox10 mutants have decreased intestinal transit even in the absence of their microbiota, identifying another primary defect in these mutants.…”

Identification of neurogenic intestinal motility patterns in silver perch (Bidyanus bidyanus) that persist over wide temperature ranges

“…patterns have been described in a number of different mammals includes cats, 3,4 rabbits, 56 pigs, 7 sheep, 8 and humans. [9][10][11] In other vertebrates, such as fish, there have been some detailed description of intestinal propagating activity, [12][13][14] and however, in comparison with mammals, our knowledge of gut motility in fish still remains relatively poor.…”