PyFibers: An open-source NEURON-Python package to simulate responses of model nerve fibers to electrical stimulation
Fig 6
Simulations of conduction block using the code in Box 3. AP = action potential; Vm = transmembrane potential. The stimulation and recording setup are shown in panel A; note that the diagram is not to scale and does not show all 25 nodes. A 10 μm MRG fiber with intrinsic activity produced by intracellular stimulation initiated at the node closest to 10% fiber length (from the left), a 20 kHz extracellular square wave (B) delivered via a point source at 50% fiber length at an electrode-fiber distance of 250 μm, and transmembrane potential recorded at the node closest to 90% fiber length. The extracellular signal was delivered from t = 50 to 100 ms (C) at 2.5 and 3 mA and the transmembrane potential at 90% fiber length was recorded (D); only the larger amplitude signal blocked action potential conduction. The search for block threshold in Box 3 yielded −2.81 mA.