Figure 7. Block of the delayed rectifier potassium current by TEA disrupts synchronization of the potassium-evoked rhythmic activity in rat substantia gelatinosa in vitro.

A, potassium-induced rhythmicity before (left panel) and after 45 min 5 mm TEA (middle panel). TEA also caused spontaneous activity in the baseline prior to potassium ejection (not shown). Such spontaneous activity was also observed during the potassium-evoked rhythm (middle panel) and consequently the power amplitude for the potassium-induced rhythm could not be determined from the power spectrum. B, TEA causes a disruption in the synchronization of the rhythm.