I was playing around with a simulation of the Hodgkin-Huxley model using their original parameters for the squid giant axon.
By applying a constant stimulation current to the model in resting state, an infinite train of action potentials is triggered, which seems reasonable. However, if the current exceeds a threshold, these APs die off very quickly as both the membrane potential and the ion conductances reach a steady state.
What is this phenomenon called? Is it a real phenomenon, or just an artefact of the Hodgkin-Huxley model?