Figure 2

Tracings of the recorded extracellular potentials as a function of time. The tracing from the electrode closest to the axon (R = 10 mm) shows a typical quadrupolar traveling wave as the impulse passes closest to the recording electrode. As the recording electrode is placed progressively further from the axon (R = 245 mm and R = 1019 mm) the quadrupolar potential from the action potential passing near the electrode is dwarfed by the dipolar potential generated as the impulse travels through the bend. The impulse begins at t = 0 at z = -100 mm and by t = 10 reaches z = -100 again. The impulse reaches the location of the recording electrode at t = 1.1. The velocity of the travelling action potential was taken as 39 m/sec.