Figure 3.

Definition of stimulation pattern and slow establishment of steady-state rebound delay. PY neurons were stimulated with rhythmic trains of hyperpolarizing pulses (downtime, hyperpolarization duration; uptime, duration without current injection; cycle period = downtime + uptime). Before stimulation the neuron fired tonically. After stimulation began the neuron initially did not fire (first two cycles) and then fired 1, 2, and finally 3 spikes, with continually decreasing rebound delay (cycles 3, 4, and 5).