Self-gating of sodium channels at neuromuscular junction

The Neuromuscular Junction (NMJ) is the place where one end plate terminal of a motor neuron forms a synapse with a muscle fiber. Unlike synapses between neurons, the NMJ is characterized by a large number of voltage-dependent sodium channels located within post-junctional folds of the muscle fiber membrane. In this work we have used a mathematical model to simulate the behavior of the voltage-dependent sodium conductance within the NMJ. Simulations were restricted to sodium channels activation while inactivation was not considered. We observed a self-gating behavior of the sodium conductance, characterized by bistability and hysteresis. According to these results, self-gating of sodium channels in post-junctional folds could contribute to enhance transmission efficiency at the NMJ.