Topic: serotonin neurons

The in vivo responses of dorsal raphe nucleus (DRN) serotonin neurons to emotionally-salient stimuli are a puzzle. Existing theories centred on reward, surprise, salience, and uncertainty individually account for some aspects of serotonergic activity but not others. Combining ideas from reinforcement learning (RL) theory with recent insights into the signal processing features of the DRN, here we find a unifying perspective in a prospective code for value. Such a code is both biologically realistic---it arises from strong spike-frequency adaptation in serotonin neurons coupled with slow decodi