Dissociation of dopaminergic and non-dopaminergic substrates for cues produced by electrical stimulation of the ventral tegmental area

The present study provides evidence for the existence of multiple substrates for cues produced by electrical stimulation of the ventral tegmental area in rats. Two different procedures were employed to assess the effects of amphetamine and haloperidol on the discrimination of high and low intensity cues produced by electrical brain stimulation (EBS). When the procedure involved frequent presentation of brief trials, amphetamine and haloperidol had no effect on the discrimination of EBS. In contrast, when the trials were less frequent and extended in duration, amphetamine enhanced the perceived intensity of the cues whereas haloperidol had the opposite effect. These results indicate that the use of different discrimination procedures may result in the measurement of separate dopaminergic and non-dopaminergic substrates for cue properties of EBS in the ventral tegmental area.