The NEURON model and MATLAB code for the paper:

Hokanson JA, Gaunt RA, Weber DJ (2018) Effects of Synchronous Electrode Pulses on Neural Recruitment During Multichannel Microstimulation. Sci Rep 8:13067
http://dx.doi.org/10.1038/s41598-018-31247-2

is available at the authors github repository
https://github.com/JimHokanson/Hokanson_sync_stim