Dopamine receptor modulation of risky decision-making

Abstract

Several psychopathological disorders related to aberrant dopamine transmission are associated with sub-optimal risky decision-making. To observe the relationship between risk and receptor specific dopamine transmission in a rodent model, we tested the effects of drugs selective to D1-like and D2-like receptors on a risky decision-making task. Then, to determine if risk preference is related to dopamine receptor expression, in situ hybridization was used to quantify region-specific D1 and D2 receptor mRNA in rats characterized in risky decision-making. Agonists and antagonists specific to D1-like receptors had no effects on risky choice; however, the D2-like agonist bromocriptine reduced risky choice. D1 mRNA abundance in nucleus accumbens shell and insular cortex were both positive predictors of baseline risk preference, while D2 mRNA abundance in orbitofrontal cortex and medial prefrontal cortex predicted risky decision-making behavior in nonlinear fashion. Additionally, increased levels of D2 mRNA in dorsal striatum were observed in risk-averse rats in comparison to risk-taking rats. Risky decision-making can be directly affected (reduced) by acute D2-like receptor activation, but trait risky decision-making appears to be a function of distinct patterns of both D1 and D2 receptor mRNA expression in various frontostriatal regions.