A significant increase in autophosphorylation of cAMP-independent protein kinase No. 11 of brain neuronal chromatin occurs in the presence of ethylnorantifeine and its demethylated analog M1 rather than allyl- and propylnorantifeine. The increase is accompanied by phosphorylation of beta-regulatory and alpha-catalytic subunits of protein kinase No. 11. The nature of the direct action of antifeines on this enzyme correlates with their effects on gene activity and long-term memory storage. Whether neuronal chromatin protein kinase No. 11 is the action target of antifeines in displaying their mnemic effects is discussed in the paper.