[Unit activity in the ventral tegmental area and the state of focused attention in the normal awake cat].

Our previous studies had indicated that electrocortical "beta" rhythms (37 Hz) that develop in the fronto-parietal area in waking, immobile and highly attentive cats, are under the control of a dopaminergic system originating from the ventral tegmental area (VTA). A single unit study has now shown that 9% of VTA cells displayed a sustained increased of their firing rate during each beta episode. These data indicate that VTA cells exert a "gate control" on the rhythmic thalamo-cortical beta system.