Phasic nucleus accumbens dopamine release encodes effort- and delay-related costs.
BACKGROUND
Optimal decision-making requires that organisms correctly evaluate both the costs and benefits of potential choices. Dopamine transmission within the nucleus accumbens (NAc) has been heavily implicated in reward-learning and decision-making, but it is unclear how dopamine release might contribute to decisions that involve costs.


METHODS
Cost-based decision-making was examined in rats trained to associate visual cues with either immediate or delayed rewards (delay manipulation) or low-effort or high-effort rewards (effort manipulation). After training, dopamine concentration within the NAc was monitored on a rapid time scale with fast-scan cyclic voltammetry.


RESULTS
Animals exhibited a preference for immediate or low-effort rewards over delayed or high-effort rewards of equal magnitude. Reward-predictive cues but not response execution or reward delivery evoked increases in NAc dopamine concentration. When only one response option was available, cue-evoked dopamine release reflected the value of the future reward, with larger increases in dopamine signaling higher-value rewards. In contrast, when both options were presented simultaneously, dopamine signaled the better of two options, regardless of the future choice.


CONCLUSIONS
Phasic dopamine signals in the NAc reflect two different types of reward cost and encode potential rather than chosen value under choice situations.
Day
Jeremy J
JJ
Department of Psychology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Jones
Joshua L
JL
Wightman
R Mark
RM
Carelli
Regina M
RM
D000818:Animals; D002755:Choice Behavior / Q000502:physiology*; D003657:Decision Making / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism*; D008297:Male; D009714:Nucleus Accumbens / Q000378:metabolism*; D010507:Periodicity; D011337:Probability Learning; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward
D004298:Dopamine
Science. 2001 Jun 29;292(5526):2499-501
11375482
J Neurosci. 2009 Apr 8;29(14):4531-41
19357278
Nat Neurosci. 2010 Jan;13(1):25-7
19904261
Biol Psychiatry. 2010 Apr 1;67(7):641-8
20034616
Science. 2005 Mar 11;307(5715):1642-5
15761155
J Neurosci. 2004 Feb 11;24(6):1265-71
14960596
Psychol Bull. 2004 Sep;130(5):769-92
15367080
J Pharmacol Exp Ther. 2003 Apr;305(1):1-8
12649346
Science. 2003 Mar 21;299(5614):1898-902
12649484
Cogn Neuropsychiatry. 2007 May;12(3):213-21
17453902
Behav Brain Res. 1994 Dec 15;65(2):221-9
7718155
Psychopharmacology (Berl). 2002 Apr;160(4):371-80
11919664
Nat Neurosci. 2007 Dec;10(12):1615-24
18026098
Science. 1997 Mar 14;275(5306):1593-9
9054347
Nat Neurosci. 2008 Aug;11(8):966-73
18660807
Neuropsychopharmacology. 2008 Jul;33(8):1966-79
17805307
Nat Neurosci. 2006 Aug;9(8):1057-63
16862149
Nat Neurosci. 2007 Aug;10(8):1020-8
17603481