Male and female Wistar rats differ in decision-making performance in a rodent version of the Iowa Gambling Task

The Iowa Gambling Task (IGT) measures decision-making processes by simulating real-life decisions involving reward, punishment, and uncertainty of outcomes. In humans, men show more choices for the advantageous option than women. Here, we investigated sex differences in a rat model of the IGT (r-IGT). In our r-IGT mildly food-deprived rats learn to differentiate a long-term advantageous arm from a long-term disadvantageous arm differing in frequency and amount of sugar pellets as well as unpalatable but not uneatable quinine-treated sugar pellets. We also used a T-maze discrimination procedure in which rats learn to differentiate a high from a low reward arm to further explore sex differences in reward-related decision-making. In line with human data, male rats showed a stronger task progression of choices for the advantageous option than female rats. Furthermore, male rats showed more win-stay and less lose-shift behaviour in the advantageous arm as the task progressed than female rats. Whilst both male and female rats had a stronger preference for the high over the small reward arm in the T-maze, males increased this preference over sessions, whilst females did not. These data are discussed in relation to sex differences in processing rewards and punishments. (C) 2012 Elsevier B.V. All rights reserved.