RT Journal Article
SR Electronic
T1 Hyperdopaminergic Mutant Mice Have Higher “Wanting” But Not “Liking” for Sweet Rewards
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 9395
OP 9402
DO 10.1523/JNEUROSCI.23-28-09395.2003
VO 23
IS 28
A1 Susana Peciña
A1 Barbara Cagniard
A1 Kent C. Berridge
A1 J. Wayne Aldridge
A1 Xiaoxi Zhuang
YR 2003
UL http://www.jneurosci.org/content/23/28/9395.abstract
AB What is the role of dopamine in natural rewards? A genetic mutant approach was taken to examine the consequences of elevated synaptic dopamine on (1) spontaneous food and water intake, (2) incentive motivation and learning to obtain a palatable sweet reward in a runway task, and (3) affective “liking” reactions elicited by the taste of sucrose. A dopamine transporter (DAT) knockdown mutation that preserves only 10% of normal DAT, and therefore causes mutant mice to have 70% elevated levels of synaptic dopamine, was used to identify dopamine effects on food intake and reward. We found that hyperdopaminergic DAT knockdown mutant mice have higher food and water intake. In a runway task, they demonstrated enhanced acquisition and greater incentive performance for a sweet reward. Hyperdopaminergic mutant mice leave the start box more quickly than wild-type mice, require fewer trials to learn, pause less often in the runway, resist distractions better, and proceed more directly to the goal. Those observations suggest that hyperdopaminergic mutant mice attribute greater incentive salience (“wanting”) to a sweet reward in the runway test. But sucrose taste fails to elicit higher orofacial “liking” reactions from mutant mice in an affective taste reactivity test. These results indicate that chronically elevated extracellular dopamine facilitates “wanting” and learning of an incentive motivation task for a sweet reward, but elevated dopamine does not increase “liking” reactions to the hedonic impact of sweet tastes.