Fig. 2. Simulated current-clamp experiments in which the model muscle fibre was depolarized from resting potentials of around –70 mV. (A) The depolarizing current was increased from 1 nA to 10 nA in 1 nA steps. In no trace is repetitive discharging observed. (B) Simulated spikes elicited by a 3 nA depolarization immediately following a 10 ms prehyperpolarizing pulse ranging from 0 (red trace) to 0.6 nA (in 0.1 nA steps; black traces) are progressively reduced in amplitude.