Related Experiment Video
Updated: Apr 26, 2026
Enhanced Spatial Mapping of Mouse Gastric Muscle Layers Using a Modified Swiss Roll Technique
Published on: November 25, 2025
Specific localization of β-Arrestin2 in myenteric plexus of mouse gastrointestinal tract
Hercules T Maguma1, Dipanjana Datta De1, Sukhada Bhave1
1Department of Pharmacology and Toxicology, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia, United States of America.
Abstract:
β-arrestin2 is a key molecule involved in signaling and internalization of activated G protein-coupled receptors including µ-opioid receptors (MOR). Previously we have shown that decreased expression of β-arrestin2 upon chronic morphine is associated with the development of opioid tolerance in the gastrointestinal tract. However, the localization of β-arrestin2 within the gastrointestinal wall is not known. In this study we found that β-arrestin2 is localized in the soma of a select group of neurons in the myenteric ganglia but not in smooth muscle. The density of β-arestin2 was significantly higher in the ileum than the colon. We identified four variants of β-arrestin2 in the ileum, with ARRB-005 and ARRB-013 being the most abundant. Further, the current study utilized multiple-labeling immunofluorescence to characterize the chemical coding of neurons expressing β-arrestin2 in the murine myenteric plexus and the co-localization of MOR1 and β-arrestin2. β-arrestin2 co-localized with choline acetyltransferase and calretinin. In contrast, β-arrestin2 neither co-localized with substance P, nitric oxide synthase nor calbindin. Genetic deletion of β-arrestin2 did not affect cholinergic neuron activation by nicotine in the isolated ileum (-log M EC50: wild type = 5.8 vs. β-arrestin2 knockout = 5.9). Our findings suggest specificity in the localization of β-arrestin2 in the myenteric plexus within MOR1-expressing neurons and provide a relation for direct intracellular crosstalk between MOR1 receptor activation and β-arrestin2 signaling in the myenteric neurons. β-arrestin2 deletion does not directly alter basal enteric cholinergic neuronal function.
Insights
Beta-arrestin2 is found in specific gut neurons, co-localizing with µ-opioid receptors. This localization suggests a direct signaling link, though its absence doesn't impact basic gut neuron function.
Area of Science:
- Gastroenterology
- Neuroscience
- Molecular Biology
Background:
- Beta-arrestin2 is crucial for G protein-coupled receptor signaling and internalization, including µ-opioid receptors (MOR).
- Previous research linked decreased beta-arrestin2 to opioid tolerance in the gastrointestinal tract.
- The precise location of beta-arrestin2 within the gastrointestinal wall was previously unknown.
Purpose of the Study:
- To determine the localization of beta-arrestin2 within the gastrointestinal wall.
- To characterize the neuronal subtypes expressing beta-arrestin2 in the myenteric plexus.
- To investigate the co-localization of beta-arrestin2 with MOR1 and other neuronal markers.
Main Methods:
- Immunofluorescence staining in murine myenteric plexus.
- Identification of beta-arrestin2 variants.
- Genetic deletion of beta-arrestin2 in mice.
- Assessment of cholinergic neuron activation via nicotine stimulation.
Main Results:
- Beta-arrestin2 is localized in the soma of myenteric neurons, not smooth muscle, with higher density in the ileum than the colon.
- Four beta-arrestin2 variants were identified in the ileum; ARRB-005 and ARRB-013 were most abundant.
- Beta-arrestin2 co-localized with choline acetyltransferase and calretinin, but not substance P, nitric oxide synthase, or calbindin.
- Genetic deletion of beta-arrestin2 did not alter basal enteric cholinergic neuronal function or activation by nicotine.
Conclusions:
- Beta-arrestin2 is specifically localized in myenteric plexus neurons expressing MOR1.
- Findings suggest direct intracellular crosstalk between MOR1 activation and beta-arrestin2 signaling in myenteric neurons.
- Beta-arrestin2 deletion does not impair basal enteric cholinergic neuronal function.
Related Concept Videos
01:27Nerve Supply of the GI Tract
The enteric nervous system consists of two major plexuses: the myenteric plexus (Auerbach's plexus) and the submucosal plexus (Meissner's plexus). These plexuses are located within the layers of...
01:05Physiology of Enteric Nervous System and Gut Health