APAMIN IMPROVES LEARNING IN AN OBJECT RECOGNITION TASK IN RATS

Object recognition was investigated in rats in a two trial unrewarded task. In the first trial, two copies of the same object were presented . In the second trial, one of the familiar object and a new object wer e presented. Rats explored the new object longer than the familiar obj ect when the intertrial time was 1 h, indicating that they remembered the familiar object, but not when the intertrial time was 24 h. Rats i njected with apamin (a toxin which blocks specifically Ca2+-activated K+-channels) before the first trial spent more time in exploring the n ew object than the familiar object at the second trial, when it took p lace 24 h after the first trial. Injection of apamin just after the fi rst trial or before the second trial did not modify the difference in exploration time between the new and the familiar object. These result s suggest that the blockade of Ca2+-activated K+-channels could improv e learning, but not consolidation nor restitution of the information, in an object recognition task. (C) 1997 Elsevier Science Ireland Ltd.