[Abstract Title]. - Society for Neuroscience

eactions to tastes, possibly implicating a sensorimotor effect, as also indicated by a reduction in
grooming behavior.
Disclosures: J.M. Richard, None; K.C. Berridge, None.
Poster
298. Neural Mechanisms of Reward: Self-Administration and Opioid Modulation
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 298.17/TT50
Topic: F.03.d. Reward
Support: NIH Grant DA017752
Title: Amphetamine effects on ventral pallidal coding of cue-triggered incentive salience and
hedonia
Authors: *C. A. ITOGA 1 , K. C. BERRIDGE 2 , J. W. ALDRIDGE 3 ;
1 Dept Neurosci, 2 Psychology Dept., 3 Dept. of Neurol., Univ. Michigan, Ann Arbor, MI
Abstract: Appetitive responses to drug cues are thought to be an important feature of drug
addiction, and cues that act as motivational magnets can pose a risk for drug relapse. The ventral
pallidum (VP) is responsive to reward-associated cues. Dopamine increases the “wanting” of
rewards, as supported by the incentive-sensitization theory of addiction (Robinson & Berridge
1993) while opiates enhance both the “wanting” and “liking” of rewards (Pecina & Berridge
2005). In this study, our aim was to determine the effects of dopamine agonists on VP neural
coding of cues for natural rewards, and correlated changes in “liking” and/or “wanting” taste
reactions.
Rats were trained in a Pavlovian association task in which all stimuli were taste infusions
directly into the mouth. Two cues (water, 0.1 mL each) were followed by reward (9% sucrose
solution, 0.1mL). The first cue provides predictive information of eventual reward delivery. The
second cue is thought to have the most incentive value, as it is temporally closer to the reward.
Changes in hedonic value were detected by behavioral taste reactions. Water on its own elicits
primarily neutral taste reactions, but as a taste cue associated with reward, its hedonic value may
be transformed to evoke positive taste reactions.
Amphetamine (1 mg/kg; ip) was used to boost dopamine levels. We hypothesized that
amphetamine would shift dominant VP responses to the incentive cue, reflecting a change in
motivation without altering hedonic responses. In rewarded trials in recordings from 10 rats
(total of 92 cells), amphetamine, compared to vehicle controls, increased the proportion of
responsive cells to the incentive (second) cue (54% vs. 35%) without altering the size of the