Effects of vagal efferent blockade on gastric motility and emptying during cervical vagus nerve stimulation measured with magnetic resonance imaging in rats

Study Purpose: This study aims to evaluate the effects of cervical vagus nerve stimulation (VNS) on gastric emptying and motility in rats. The aim is to selectively activate afferent pathway (with and without blockade of the efferent pathway) to disentangle their differential effects on gastric responses.

Data Collection: A multi‐slice MRI sequence was used to scan antral contractions with high spatial and temporal resolution.

Primary Conclusion: None stated

Curator's Notes

Experimental Design: Male rats, ranging from 272 to 306g body weight, were used in this study. All animals underwent abdominal surgery for implantation of a patch electrode on the forestomach. The animals were allowed at least 1 week for post-surgical recovery. A gadolinium‐based contrast agent was mixed with the animal’s meal in order for chyme to appear “bright” in MRI scans, thereby delineating the gastric and intestinal volume. A multi‐slice MRI sequence was used to scan gastrointestinal (GI) functions and physiology with high spatial and temporal resolution. The experimental procedures for MRI are described in Section 6 (Effects of vagal efferent blockade on gastric motility and emptying during cervical vagus nerve stimulation measured with MRI) of the following protocol.

Completeness: This is a part of a larger study: "Effects of Vagus Nerve Stimulation/Gastric Electrical Stimulation on Gastric Emptying and Motility Assessed with Magnetic Resonance Imaging"

Subjects & Samples: This study used adult Sprague-Dawley (RRID:RGD_70508) male rats (n=9) between 9-11 weeks old.

Primary vs derivative data: Primary data is organized by subject ID. Each subject folder contains motility and volume performance subfolders with 3D+ time motility MRI data before onset and during various VNS parameters. Derived data consists of segmentation of antrum and antral motility maps for each experimental subject.