I want to let Plos CB readers know that two bugs in 2D code, associated which this paper and posted on Model DB, strongly affect results described in the paper.
https://senselab.med.yale...

The first bug is that: matlab part of this model generates two matrices 4001x4001 points of Ex and Ey components of electric field. Matlab code writes these matrices into text files. NEURON code reads matrices of size 4000x4000 from these files. As a result each line in electric field matrices is shifted by one element in NEURON model. That creates very strong, unreal gradient of electric field.

The second one is connected to NEURON's representation of compartments. Authors add artificial long axon to multi-compartment model of pyramidal neuron. Unfortunately they used 'parent' coordinates for each axon segments. NEURON sorts this out and draws this axon as line, because compartments connect to each other. However in magnetism.hoc, authors use vertices position to calculate current induced by magnetic field. That means all axon compartments are located in the same position in the electric field (you can find this if scan 3d vertices of the axon's compartments). This place is exactly the place where 'artificial' gradient in electric field appears. As a result, strong axial current in axon is generated by these two bugs.

Unfortunately, when I fixed these bugs, I couldn't get spike in this model even when I applied several thousands kV to coil.

This link shows: how it should be(left) and how it actually is (right) in the code from model DB
http://nisms.krinc.ru/rth...

Please feel free contact me if for need more detailed description of these bugs.


_{I thank Natalie Schaworonkow for her suggestion to publish this comment.}