Video Imaging and Spatiotemporal Maps to Analyze Gastrointestinal Motility in Mice

Abstract

The enteric nervous system (ENS) plays an important role in regulating gastrointestinal (GI) motility and can function independently of the central nervous system. Changes in ENS function are a major cause of GI symptoms and disease and may contribute to GI symptoms reported in neuropsychiatric disorders including autism. It is well established that isolated colon segments generate spontaneous, rhythmic contractions known as Colonic Migrating Motor Complexes (CMMCs). A procedure to analyze the enteric neural regulation of CMMCs in ex vivo preparations of mouse colon is described. The colon is dissected from the animal and flushed to remove fecal content prior to being cannulated in an organ bath. Data is acquired via a video camera positioned above the organ bath and converted to high-resolution spatiotemporal maps via an inhouse software package. Using this technique, baseline contractile patterns and pharmacological effects on ENS function in colon segments can be compared over 3-4 hr. In addition, propagation length and speed of CMMCs can be recorded as well as changes in gut diameter and contraction frequency. This technique is useful for characterizing gastrointestinal motility patterns in transgenic mouse models (and in other species including rat and guinea pig). In this way, pharmacologically induced changes in CMMCs are recorded in wild type mice and in the Neuroligin-3 R451C mouse model of autism. Furthermore, this technique can be applied to other regions of the GI tract including the duodenum, jejunum and ileum and at different developmental ages in mice. Video LinkThe video component of this article can be found at

Gastrointestinal dysfunction in patients and mice expressing the autism‐associated R451C mutation in neuroligin‐3

“…Previously, we showed that the NL3 R451C mutation decreases colonic motility in response to the serotonergic receptor antagonist, tropisetron compared to WT mice [Swaminathan et al, ]. Whether gut function is changed due to altered neural function involving GABA neurotransmission as reported in the brain of these mice [Etherton et al, ; Tabuchi et al, ] is unknown.…”

“…Whether gut function is changed due to altered neural function involving GABA neurotransmission as reported in the brain of these mice [Etherton et al, 2011;Tabuchi et al, 2007] is unknown. The use of the video-imaging assay to quantify changes in colonic motility is well established for examining ENS function [Balasuriya, Hill-Yardin, Gershon, & Bornstein, 2016;Roberts et al, 2008;Swaminathan et al, 2016]. This approach takes advantage of the fact that when mouse colon is isolated from the CNS and maintained ex vivo, enteric neural activity drives a stereotyped repetitive motor pattern, the CMMC (Fig.…”

“…Motor activity was recorded at baseline (1 hr), with bath‐applied antagonist (1 hr), and during washout (1 hr). Pseudocolored spatiotemporal maps of motor patterns were created and motor pattern frequencies were quantified using in‐house software [Neal et al, ; Swaminathan et al, ] (Fig. S1).…”

“…Ileal samples from two WT and two NL3 R451C mice show bands at the expected size showing a 40 bp shift due to neocassette insertion [Tabuchi et al, 2007]. motor patterns were created and motor pattern frequencies were quantified using in-house software [Neal et al, 2009;Swaminathan et al, 2016] (Fig. S1).…”

“…Here, we characterized GI motility in the small intestine in vivo in wild-type (WT) and NL3 R451C mice. We additionally exploited an ex vivo motility approach [Roberts, Bornstein, Bergner, & Young, 2008;Swaminathan et al, 2016] in the large intestine to assess for subtle changes in GI neurotransmitter pathways in NL3 R451C mice. We further assessed for changes in neuronal subpopulations in the myenteric plexus in this model.…”