This paper describes the synthesis of beta-(dialkylaminomethyl)-gamma- butyrolactones (6 and 15) and their tetrahydrofuran analogs 7 and 16. Their convulsant activity was studied on mice and could display an antiGABAergic component, but, unlike the alpha-(dialkylaminomethyl)- gamma-butyrolactones, no antiglycinergic component was detected. The possibility of an activation of the glutamatergic receptors (NMDA), by indirect stimulation of their glycinergic site, by the tetrahydrofurans analogs 7 could be considered. These compounds exhibited, at low doses (1/3 to 1/20 of their convulsant doses), an anticonvulsant action in the maximal electroshock test and this is in agreement with the abovementioned possibility.