The Influence of Electroconvulsive Shock on Learning and Retention of Memory in Rat
The influence of maximal electroconvulsive shock (MECS) on the ability to learn and on memory retention was investigated in male Wistar rats, 30–80 days of age. Animals were kept under conditions of unrestrained food and water intake and a 12 hours light-day-darkness cycle. Conditioning of animals with thirty trials per day over ten days was performed in a shuttle-box using light as the conditioned stimulus and foot shock (1 mA, 4 s) as the unconditioned stimulus. Electroconvulsive activity was elicited with a current (up to 85v, 100 Hz) applied through ear clips. A correct response was taken to be an escape reaction to the other part of the shuttle box within three minutes following light onset which preceded the painful electrical stimulus. The rats that by the seventh day of training did not produce a single positive avoidance response were eliminated from the study. Rats were separated into three groups: the control group did not receive electric ear shock; the second group received ECS thirty minutes before conditioning and the third group received ECS immediately after conditioning, respectively.