This is the readme for a NEURON simulator model associated with the paper: Chandler WK, Hodgkin AL (1965) The effect of internal sodium on the action potential in the presence of different internal anions. J Physiol 181:594-611 This model was contributede by Michael Hines who created the model in collaboration with John Moore. NEURON is required to run this model and is freely available at http://www.neuron.yale.edu The model demonstrates the "cannula artifact" discussed in the paper (see Fig 5 in the paper and it's corresponding linear circuit model displayed when you run the model in this archive). The artifact makes it appear as though you are recording an Action Potential voltage greater than the sodium (Na+) reversal potential when this shouldn't be possible. Model usage: either auto-launch from modeldb or download and extract this archive and start with the mosinit.hoc. For more help on starting the model see: https://senselab.med.yale.edu/ModelDB/NEURON_DwnldGuide.cshtml Once the model starts it completes quickly and generates a graph: where the red trace shows a recorded action potential reaching 58 volts while ena=50 thus demonstrating the cannula artifact (see figure 8 b bottom's 3mm similar AP).