Fig. 6.

Influence of current, input frequency, and treatment on the number of spikes per sine wave cycle. The number of spikes per cycle decreases steeply with increasing input frequency and increases with increasing current injection amplitude. There was a significant treatment effect, with DNE cells (■) generating fewer spikes per cycle than control cells (○), but only at the 2 lowest input frequencies and at the 2 highest levels of injected current (see results). The region of phase locking (1 spike per sine wave cycle, horizontal dashed line) increased progressively with increases in sine wave amplitude.