Delayed-response improvement in frontal rats after electroconvulsive shock treatments and spacing of tirals.

Frontal rats, subjected to electroconvulsive shock (ECS) after each experimental session, performed better than they did before ECS treatment. The other subjects, which were treated with ECS after every third session, showed lower error scores on days immediately folloiwing ECS administration that 2 or 3 days later. When only ane trial was applied every 3-4 days, the performance of the frontal rat did not differ significantly from that of normal rats. It is concluded that in both experiments improvement resulted from the decrease of retention of the returning route from previous sessions.