Fig. 11

Stimulation amplitude affected heart rate (HR) and laryngeal muscle activation (EMG) in vivo and in computational models. A Normalized heart rate (HR; dashed lines) decreased with increased amplitude for all animals. Onset of changes in heart rate occurred at ~ 0.6xBCT (BCT = bradycardia threshold). Normalized EMG responses (solid lines) across stimulation amplitudes varied between animals. Onset of EMG response occurred at ~ 0.4xBCT to 0.6xBCT, and the normalized EMG increased with stimulation amplitude (n = 5 animals). Color denotes animal. B Illustrative EMG signals from one animal (LV4) in response to a single pulse delivered at different stimulation amplitudes (color). Stimulation onset and artifact are represented as an arrow and grey box, respectively. Increased stimulation amplitude resulted in shorter EMG latency, change in EMG waveform, and merging of EMG and stimulation artifact. C Finite element model of the mouse vagus nerve and bipolar cuff electrode. The perineurium sheath around the fascicle and the surrounding muscle are not shown. D Recruitment curves for model A and B fibers colored to indicate fiber diameter. E Recruitment curves for model A and B fibers colored to indicate fiber jitter (i.e., the relative position of the center node of Ranvier along the length of the nerve)