[Effect of adrenocorticotropin fragments on the memory of Tenebrio molitor beetles]

Fragments of the adrenocorticotropic hormone ACTH1-24 and ACTH5-7 facilitate memory in the beetle T. molitor, the effect being observed at different stages after learning. An analogue of ACTH5-7 which contains D-phenylalamine, as well as D-phen7-ACTH4-7, inhibit memorization (the results checked 1 day after learning) and induce some other disturbances in the behaviour of beetles. To the 10th day of learning, the effects of the analogues cannot be distinguished from those of L-Phe7-fragments. The results obtained are compared with the known effect of ACTH fragments on memory in vertebrates.