Figure 1:

A summary of some of the neural circuits involved in risk/reward decision-making involving choice between smaller certain and larger uncertain (or risky) rewards. (A) Depiction of the probabilistic discounting task used to asses risk/reward decision-making in rodents. (B) Summary of the dissociable functions of cortical, limbic and striatal nodes within DA circuitry in regulating probabilistic discounting, as inferred by inactivation and circuit disconnection studies. BLA inactivation reduces risky choice by increasing sensitivity to reward omissions (bottom right). Subcortical circuits incorporating the BLA and the NAc bias choices towards larger uncertain rewards, as disconnection between these regions reduces risky choice [bottom center: adapted from St Onge et al., (2012b)]. In contrast, the medial OFC tempers the impact that large, uncertain rewards exert over subsequent choices, as inactivation of this region increases risky choice [bottom left: adapted from Stopper et al., (2014a)]. Inactivation of the prelimbic region of the medial PFC impairs modifications in decision biases, affecting risky choice differentially depending on whether reward probabilities decrease or increase over time [top left: adapted from St Onge and Floresco, (2010)]. This function of the medial PFC is mediated via top-down interactions with the BLA; disconnection of descending PFC→BLA projections also impairs shifts in choice biases [top right: adapted from St Onge et al., (2012b)]. DA further refines risk/reward decision-making, with D1 receptors in the PFC and NAc reducing the impact of non-rewarded choices, and D2 receptors in the medial PFC facilitating adjustments in choice biases to promote exploration of different options (center). For all panels, stars denote significant differences between groups at p<0.05.