The effect of AP and DMAA on the activity of Ro4-1284-induced PGO waves in lateral geniculate body (CGL) of cats is bidirectional. Higher doses decrease, whereas lower doses increase the intensity of PGO waves. DMAA inhibitis PGO activity in a dose-dependent manner. SP antagonizes AP inhibiting activity but does not affect the action of DMAA. The present study deals with the effect of AP and DMAA, the compounds stimulating central dopamine receptors, on the function of serotonin neurons.