DOPAMINERGIC REGULATION OF FEEDING-BEHAVIOR .2. DIFFERENTIAL-EFFECTS OF AMPHETAMINE MICROINFUSION INTO 3 STRIATAL SUBREGIONS

This study examined the involvement of intrastriatal dopaminergic mechanisms on feeding and spontaneous locomotor activity in food-deprived (19 h) rats. In three separate experiments, amphetamine (0, 1, 10, and 20-mu-g/0.5-mu-l) was bilaterally infused into the nucleus accumbens (N.Acc.), the ventrolateral striatum (VLS), or the dorsolateral striatum (DLS). Administration of the higher doses of amphetamine into both the N.Acc. and the VLS reduced feeding. However, the overall profiles of behavior suggested different underlying mechanisms. Treatment of the DLS did not appear to influence ingestive behaviors. Locomotor activity and oral stereotypy were differentially affected by drug infusion into the three sites. The data suggest that dopamine transmission in the N.Acc. may be important for attentional mechanisms that regulate the temporal distribution of competing behaviors. In contrast, the VLS appears to mediate oral motor functions that are critical for feeding. The DLS appears to be minimally involved in regulating either behavior.