Characteristics of learning and memory in streptozocin-induced diabetic mice.

We demonstrated that mice with streptozocin-induced diabetes mellitus have normal acquisition for relatively simple tasks but show problems in learning more complex tasks such as shuttle box avoidance. Enhanced learning previously reported in simple passive avoidance tasks appears to be due to increased foot shock sensitivity. Diabetic mice show a marked memory retention deficit after learning an active avoidance T-maze task. This retention deficit was reversed by a single injection of insulin, suggesting that it may be related to hyperglycemia per se. Diabetic mice have a shift to the left in the inverted U-shaped dose-response curve for memory retention produced by the acetylcholine agonist arecoline. Based on a preliminary screening, responses to several other pharmacological memory enhancers are probably altered in diabetic mice. These studies suggest that this mouse model of diabetes mellitus demonstrates a deficit in memory retention and retrieval similar to that seen in humans with diabetes mellitus.