Open Collections

Mesocortical dopaminergic regulation of cue-guided risk/reward decision making

University of British Columbia

When seeking reward, we are often faced with decisions between options that pay out often but yield low rewards and those that are relatively riskier but more profitable when they pay off. Human behavioral paradigms used to study this type of decision making often give participants explicit cues associated with the probability of reward. Conversely, rodent decision-making paradigms generally require the animal to develop internal representations of reward contingencies to guide decision-making in the absence of explicit cues. Human and rodent studies have uncovered a role for dopamine transmission in the medial prefrontal cortex (mPFC) in risky decision making, however, it is unclear if cortical dopamine serves the same purpose in cue-guided and non-cue-guided decision-making contexts. Our group has recently developed a rodent decision-making assay to bridge this gap named the “Blackjack task”. In this task, rats choose between a small/certain option that delivers 1 sugar pellet 100% of the time and a large/risky option that delivers 4 sugar pellets, probabilistically. The chance of the large/risky option being rewarded is signaled by two distinct auditory cues (signaling either 50% or 12.5% chance of reward). Previously, using this task, we have shown that the dorsal mPFC facilitates risk taking when the odds are favorable whereas the ventral mPFC inhibits risk taking when the odds are poor. Our lab has also demonstrated dissociable roles for cortical dopamine D1 and D2 receptors during un-cued risk reward decision making, however, the role for dopamine receptors in the mPFC during cued risk/reward decision making remains unknown. Here, we assess the effect of blockade of dopamine D1 and D2 receptors in the dorsal and ventral mPFC in male rats. Dopamine D2 (but surprisingly, not D1) receptors in the dorsal mPFC promote risky choice when the odds are favorable by promoting flexible responding to dynamically changing reward contingencies. Cue-guided risk/reward decision making in the ventral mPFC, however, is not dependent on D1 and D2 receptors. These data highlight a role for prefrontal dopamine receptors in cue-guided risk/reward decision making that is distinct from other types of risk/reward decision making, sub-region dependent and specific to D2 receptors.

Text

2020-08-19

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/75606

Psychology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/