The nature of the~ sychotropic activity of crown esters is determined chiefly by the size of their macrocyclic cavity [i, 6]. Polyesters containing 15-18 atoms in the ring, as well as their benzo derivatives, increase motor activity, decrease the duration of pentobarbital sleep of experimental animals, potentiate the convulsive action of corazole and electroshock, induce a degradation of certain reflexes, tremors, and in sublethal doses, clonic convulsions [i, 4, ...