ATP-sensitive potassium channels mediate the effects of a peripheral injection of glucose on memory storage in an inhibitory avoidance task

A peripheral injection of glucose has been found to improve memory in rats, but the underlying mechanisms are unknown. One possible mechanism by which peripheral glucose might act on memory storage is by regulating ATP-sensit ive potassium (K-ATP) channels. The present study investigated the effects of K-ATP channel modulators (minoxidil, a K-ATP channel opener and glibencl amide, a K-ATP channel closer) on memory enhancement induced by peripheral injection of glucose in an inhibitory avoidance task. Rats were trained in a one trial inhibitory avoidance task (50 Hz, 1 mA, 3 s footshock), and min oxidil (12.5, 25 or 50 mg/kg) or glibenclamide (2.5, 5, 10 or 20 mg/kg) was injected interaperitoneally (I.P) 30 min before training. Immediately afte r training the rats were injected with glucose (100 mg/kg, IT). Retention w as tested 2 days later. The results indicate that systemic post-training in jection of glucose improved memory storage and this effect was attenuated a nd enhanced by pretreatment of minoxidil and glibenclamide, respectively. T he drug minoxidil or glibenclamide alone did not significantly affect memor y storage. This shows that K-ATP channels mediate the memory improving effe cts of systemic glucose. (C) 2001 Elsevier Science B.V. All rights reserved .