Influence of nootropic drugs on the memory-impairing effect of diethyldithiocarbamate and clonidine in "step down" passive avoidance in albino rats.

Experiments on albino rats were carried out to study the effects of the nootropic drugs piracetam, aniracetam, meclofenoxate and fipexide on the DA-beta-hydroxylase inhibitor diethyldithiocarbamate- and the alpha 2-adrenoceptor agonist clonidine-impaired cognitive functions. The changes in memory were studied by the step down passive avoidance with punishment reinforcement. Diethyldithiocarbamate, injected intraperitoneally at a dose of 300 mg/kg and clonidine at a dose of 0.1 mg/kg i. p. considerably impaired retention for passive avoidance. The administration of piracetam (600 mg/kg), aniracetam (50 mg/kg), meclofenoxate (100 mg/kg) and fipexide (10 mg/kg) orally for 5 days prior to training completely abolished the memory-impairing effect of diethyldithiocarbamate and clonidine. The role of NAergic neurotransmitter system for the memory disturbances caused by diethyldithiocarbamate and clonidine as well as for the protective effects of the nootropic agents tested is discussed.