The regulatory effect of dipeptides on cell proliferation in mammalian nerve tissue culture and olfactory associative learning in insects

The study addresses the effects of dipeptides AspPro and AspSer and their constituent amino acids (aspartic acid—Asp, proline—Pro, and serine—Ser) on proliferative activity of rat brain cortical and subcortical tissue explants and functional activity of the honeybee central nervous system. The area index was calculated as a ratio of the total explant area to the area of its central zone. The number of bees which exhibited a conditioned response, namely proboscis extension towards the odorized solution, 1 min (short-term memory) and 180 min (long-term memory) after single trial learning was also measured. Both dipeptides, as well as aspartate itself, stimulated the expansion of the growth zone of rat subcortical tissue explants and increased the number of bees that retained in their short-term/long-term memory the acquired conditioned response, regardless of the effect of the second component of the dipeptide. The similarity of these effects suggests that common mechanisms of reception and signal transduction have evolved in insects and mammals, and this requires further study.