Format

Send to

Choose Destination
Biol Psychiatry. 2013 Apr 15;73(8):747-55. doi: 10.1016/j.biopsych.2012.12.005. Epub 2013 Jan 29.

Phasic mesolimbic dopamine release tracks reward seeking during expression of Pavlovian-to-instrumental transfer.

Author information

1
Department of Psychology, University of California, Los Angeles, CA 90095, USA. kwassum@ucla.edu

Abstract

BACKGROUND:

Recent theories addressing mesolimbic dopamine's role in reward processing emphasize two apparently distinct functions, one in reinforcement learning (i.e., prediction error) and another in incentive motivation (i.e., the invigoration of reward seeking elicited by reward-paired cues). Here, we evaluate the latter.

METHODS:

Using fast-scan cyclic voltammetry, we monitored, in real time, dopamine release in the nucleus accumbens core of rats (n = 9) during a Pavlovian-to-instrumental transfer task in which the effects of a reward-predictive cue on an independently trained instrumental action were assessed. Voltammetric data were parsed into slow and phasic components to determine whether these forms of dopamine signaling were differentially related to task performance.

RESULTS:

We found that a reward-paired cue, which increased reward-seeking actions, induced an increase in phasic mesolimbic dopamine release and produced slower elevations in extracellular dopamine. Interestingly, phasic dopamine release was temporally related to and positively correlated with lever-press activity generally, while slow dopamine changes were not significantly related to such activity. Importantly, the propensity of the reward-paired cue to increase lever pressing was predicted by the amplitude of phasic dopamine release events, indicating a possible mechanism through which cues initiate reward-seeking actions.

CONCLUSIONS:

These data suggest that those phasic mesolimbic dopamine release events thought to signal reward prediction error may also be related to the incentive motivational impact of reward-paired cues on reward-seeking actions.

PMID:
23374641
PMCID:
PMC3615104
DOI:
10.1016/j.biopsych.2012.12.005
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center