Figure 6.

D2 receptor mRNA expression in prefrontal cortex and striatum. a–f, D2 mRNA expression in orbitofrontal cortex predicted risk-taking as a U function: high levels of D2 expression predicted either high or low risk-taking (a). The opposite relationship was evident in medial prefrontal cortex, with low D2 expression predicting high or low risk-taking (b). D2 mRNA expression in dorsal striatum negatively predicted risky decision-making: lower levels of hybridization predicted greater risk-taking (d). There were no relationships between D2 mRNA expression in insular cortex or either region of nucleus accumbens and risky decision-making (c, e, f). All bar graphs represent means + SEM. *p < 0.05, Tukey's HSD post hoc test.