N-palmitoyl glycine (PG), synthesized by the mixed anhydrides method, displayed nootropic effects (in the "step-down" test) as well as an anti-immobility action in the forced swimming test, in mice. However no anticonvulsant effects were obtained, even at high dose (300 mg/Kg, po), in the maximal electroshock or against the convulsions induced by pentetrazol. In the study reported in this paper PG potentiated the reserpine or the haloperidol catalepsy in rats. The potentiation of the haloperidol catalepsy was antagonized by imipramine which displayed antiglutamatergic and antimuscarinic properties. On the other hand at 150 mg/Kg (ip), a dose which potentiated the haloperidol catalepsy, PG stimulated the dopaminergic function in the striatum. These results could therefore constitute a first clue suggesting a stimulation, by PG, of the cholinergic and GABAergic interneurons, by glycinergic potentiation of the NMDA receptors in the striatum.