This is the XPP model associated with the paper:

Ratté S, Zhu Y, Lee KY, Prescott SA (2014) Criticality and degeneracy in injury-induced changes in primary afferent excitability and the implications for neuropathic pain. Elife 3:e02370

This ModelDB entry contains the authors original code as downloaded from the authors web site:
http://prescottlab.ca/code-for-models
on 20190510.