Effect of Dihydrexidine Hydrochloride on Early Consolidation and Retrieval of Long-Term Memory in Rats with Different...

We studied the participation of the brain dopaminergic system in cognitive processes in rats on the model of spatial learning in the Morris water maze. Administration of the dopamine D1/5-receptor agonist dihydrexidine hydrochloride during repeated training in the Morris water maze resulted in improvement of early memory consolidation by the platform search time index selectively in animals with low abilities to perform the task at this stage of training, but not in individuals with high abilities to early memory consolidation. The agonist was also ineffective in rats with low memory consolidation abilities at all stages of memory formation. In the retrieval phase after repeated training, the agonist improved the retrieval of the skill in rats with low abilities to perform the task. The results illustrate the involvement of the brain dopaminergic system in rats not only in the processes of early spatial memory consolidation, but also in the retrieval of the memory trace after learning.