Fig. 1. Propagated action potentials from the giant axons of four species of squid. Single propagated action potentials were recorded from giant axons using intracellular microelectrodes. (A) Action potentials from four species. (B) Action potentials from A superimposed by aligning peaks. All recordings were made at 15°C. Axons were bathed in 10K ASW (see Materials and methods).