Dipeptides Beta- L-Aspartyl-Serine and Beta-L-Aspartyl-Proline in Memory Regulation in the Honeybee

We report a comparative analysis of the effect of alpha- and beta- isomers of the dipeptides aspartyl-serine and aspartyl-proline on the ability of honeybees to retain the conditioned food reflex to olfactory cues in their short-term/long-term memory. Stimulatory/inhibitory effects of the alpha-dipeptides on memory processes are confined to the concentration range of 10-6–10-8 M. In contrast, beta-dipeptides exert stimulatory/inhibitory effects on memory not only within the same range but also at ultra-low (pico- and femtomolar) concentrations. At concentrations of 10-9–10-11 M, beta-dipeptides have no effect on the characteristics under study (“silence zone”). Thus, we revealed fundamental differences in the effects of alpha- and beta- dipeptide isomers on the memory regulation.