The Long and the Short of Serotonergic Stimulation: Optogenetic activation of dorsal raphe serotonergic neurons changes the learning rate for rewards

Abstract

Serotonin plays an influential, but computationally obscure, modulatory role in many aspects of normal and dysfunctional learning and cognition. Here, we studied the impact of optogenetic stimulation of dorsal raphe serotonin neurons in mice performing a non-stationary, reward-driven, foraging task. We report that activation of serotonin neurons significantly boosted learning rates for choices following long inter-trial-intervals that were driven by the recent history of reinforcement.