Influence of diethyldithiocarbamate (DDC) on the memory-facilitating effect of some central stimulants.

Diethyldithiocarbamate (DDC) introduced in a dose of 400 mg/kg 3 hours before training slightly deteriorates learning in albino rats in a maze. Upon testing 24 hours and 14 days after training, DDC is found to impair markedly the retention indices, when introduced both before and immediately after the end of the training. On the background of DDC, the stimulants caffeine, strychnine, amphetamine, echinopsine and centredrine do not manifest their typical memory-facilitating effect. According to data from the literature and from our previous experiments it is known that the DDC dose used lowers the noradrenaline level in the brain by more than 50 per cent. This suggests that the realization of the memory-facilitating effect of these central stimulants with different basic mechanisms of action requires optimum functional activity of the noradrenergic brain system, as well as this has been established in other experiments for the cholinergic system.