Pig-specific computational models of monopolar vagus nerve stimulation with a six-contact cuff electrode

Study Purpose: To implement, simulate, and analyze computational models of pig vagus nerve stimulation (VNS) with the six-contact ImThera cuff electrode using nerve morphology and cuff placement that correspond to animal-specific experiments.

Data Collection: We used ASCENT v1.0.1 to build a 3D model of six pig vagus nerves instrumented with a six-contact cuff electrode. We simulated monopolar thresholds for 3 um “B” and 13 um “A alpha” fibers, which we compared to heart rate and laryngeal electromyogram (EMG) in vivo responses, respectively.

Primary Conclusion: Currents sufficient to activate B fibers also robustly activated A alpha fibers. Models accurately predicted A alpha onset thresholds, A alpha saturation thresholds, and B onset thresholds, but underestimated B saturation thresholds.

Curator's Notes

Experimental Design: This is a computational study.

Completeness: This dataset is complete.

Subjects & Samples: Only virtual subjects were used in this study. We modeled six right cervical pig vagus nerves. Histology and experimental data obtained from miniature swine subjects originate from https://doi.org/10.26275/efbj-8evl.

Primary vs derivative data: Primary data folder contains three data elements.

1. Nerve morphology: The files in primary/sub-*/sam-*-sub-*/samples/*/slides/0/0/masks/ are the histology and segmentations of the vagus nerve morphology at the site of stimulation for this specific subject/sample. The data are also published in the associated: https://doi.org/10.26275/efbj-8evl.

2. Model inputs and outputs: The files in primary/sub-*/sam-*-sub-*/samples/*/ are ASCENT input configuration files (i.e., sample.json, models/*/model.json) and outputs (i.e., individual fiber activation thresholds models/*/sims/*/n_sims/*/data/outputs/thresh_inner*_fiber*.dat). Additionally, the files in primary/sub-*/sam-*-sub-*/samples/*/ contain key intermediate files created by ASCENT, including the extracellular potentials applied to the fiber models (models/*/sims/*/n_sims/*/data/inputs/inner*_fiber*.dat) and the stimulation waveform (models/*/sims/*/n_sims/*/data/inputs/waveform.dat).

3. In vivo recordings for model validation: The files in primary/sub-*/sam-*-sub-*/samples/*/ephys/ contain electrophysiological recordings (i.e., EMG, EKG) in response to vagus nerve stimulation for this specific subject/sample combination. The data are also published in the associated: https://doi.org/10.26275/efbj-8evl.

Code Availability: Run the plotting scripts in the dataset using ASCENT v1.1.0 (repository; documentation): see README.txt for details.