TY - JOUR T1 - Activation of serotonin neurons promotes active exploitation in a probabilistic foraging task JF - bioRxiv DO - 10.1101/170472 SP - 170472 AU - Eran Lottem AU - Dhruba Banerjee AU - Pietro Vertechi AU - Dario Sarra AU - Matthijs oude Lohuis AU - Zachary F. Mainen Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/07/31/170472.abstract N2 - The neuromodulator serotonin (5-HT) has been implicated in a variety of functions that involve patience or impulse control. For example, activation of 5-HT neurons promotes waiting for delayed rewards. Many of these effects are consistent with a long-standing theory that 5-HT promotes behavioral inhibition, a motivational bias favoring passive over active behaviors. To further test this idea, we studied the impact of 5-HT in a probabilistic foraging task, in which mice must learn the statistics of the environment and infer when to leave a depleted foraging site for the next. Critically, mice were required to actively nose poke in order to exploit a given site. We found that optogenetic activation of 5-HT neurons in the dorsal raphe nucleus increased the willingness of mice to actively attempt to exploit a reward site before giving up. These results indicate that behavioral inhibition is not an adequate description of 5-HT function and suggest that a unified account must be based on a higher-order function. ER -