[An analysis of participation of central noradrenergic structures in the process of memory trace reproduction]

Variations of the noradrenaline content in noradrenergic terminals of different nuclei of the limbic system and the anterior hypothalamus were studied by the limuniscent histochemical method in the course of reproduction of a series of conditioned reflex reacitions in male Wistar rats. Both in reproduction of a conditioned passive avoiding responce and in training with inevitable conditioned reinforcement, a decrease of the noradrenaline content was found as compared with the control level. A lesser decrease was observed both in the animals that had been trained but did not reproduce the relfex reaction, and in the trained animals after repeated testing for 4 days following the training. The reproduction of the conditioned active avoiding response in shuttle box did not entail variations in the noradrenaline content.