Enhancement of responsiveness of the central serotonergic system and serotonin-2 receptor density in rat frontal cortex by electroconvulsive treatment.

The effect of a series of 10 electroconvulsive shocks (ECS) on the hyperthermic response of heat-adapted rats to a serotonergic stimulant, 3-chlorophenylpiperazine (CPP), and on radioligand binding to serotonin-1 and serotonin-2 receptors in frontal cortical membranes was investigated. Chronic ECS augmented the hyperthermic response of rats to CPP, did not affect [3H]serotonin binding to serotonin-1 receptors, and increased [3H]spiroperidol binding to serotonin-2 receptors. The treatment increased the density of serotonin-2 receptors by about 40%. It is suggested that the increased responsiveness of the central serotonergic system may be an important factor in the antidepressant action of chronic ECS.