Neuroscience: Making risk-takers settle.

Abstract

In rats, individual differences in risk preference and in sensitivity to gains compared with losses are controlled by a specific neuronal population, stimulation of which neutralizes risk-seeking behaviour. See Letter p.642 Some people are risk-seekers and others risk-avoiders, and even risk-avoiders sometimes make risky choices; the neural substrate of this variability is not known. Karl Deisseroth and colleagues show in rats that increased activity of dopamine receptor type 2 (D2R)-expressing cells in the nucleus accumbens during a 'decision' period reflects a 'loss' outcome of the previous decision and predicts a subsequent safe choice. Individual differences in the size of the activity increase correlated with risk preference. By artificially increasing the activity of D2R neurons during the decision period, the authors could turn risk-seeking rats into risk-avoiding rats. These results indicate that state and trait variations in risk preference are controlled by D2R-expressing nucleus accumbens neurons.