INFLUENCE OF VENTRAL TEGMENTAL AREA (A10 REGION) ON FLIGHT BEHAVIOR ELICITED BY HYPOTHALAMIC-STIMULATION IN THE CAT

The influence of the ventral tegmental area (VTA) (dopaminergic A10 gr oup neurons) on flight behaviour, induced by hypothalamic stimulation, was studied in the cat. Co-stimulation of hypothalamus and VTA (ipsi- or contralateral) induced an increase of the flight latency. Slow-mot ion analysis of flight behaviour showed that this increase was due to the augmentation of the fixation latency (FL) whereas the upright late ncy (UL) was not modified. Sulpiride injection (50 mg/kg i.p.) provoke d the disappearance of VTA effect without affecting the basal behaviou ral sequence. The results show that DA A10 group neurons increase the attentive component of the flight reaction, suggesting a possible infl uence of the DA A10 system on the mechanisms modulating focused attent ion in the animal.