PIRACETAM INHIBITS PAVLOVIAN EXTINCTION AND REVERSAL-LEARNING IN A SPATIAL TASK FOR RATS

Young male rats: trained in a spatial three-choice test, snowed improv ed task acquisition after chronic treatment with piracetam (250 mg kg( -1)). After reaching a learning criterion; one group of animals was ob served during Pavlovian extinction of the task skill and another group was assigned to reversal learning. The rate of extinction was slowed down in piracetam treated specimens compared to control animals. Durin g reversal training, a new choice had to be learned while the previous ly acquired choice was no longer reinforced. Acquisition of the new sk ill was significantly impeded by piracetam in contrast to acquisition of the first skill, which was facilitated. Also during reversal learni ng: the piracetam treated group persevered longer than the control gro up in repealing the first acquired choice at the expense of learning t he new choice. It is therefore suggested, that the impediment of rever sal learning was caused by inhibition of extinction. In an open-field test, the time spent exploring in motion was increased by piracetam wh ile the velocity of locomotion was unaffected by the drug. In a novelt y test, piracetam increased the rate of loss of interactions with the novel object. (C) 1998 Elsevier Science Ltd. All rights reserved.