Tachykinin 1 neurons in the lateral habenula signal negative reward prediction error

neurons show little modulation to other task-related events and are only weakly driven by aversive stimuli. Together, these data demonstrate that Tac1 marks a subpopulation of LHb neurons that encodes valence-biased prediction errors, preferentially responding to worse-than-expected outcomes in appetitive contexts. Our results provide insight into cell-type-specific contributions of habenular neurons in nRPE signaling and enable more targeted manipulations to understand their role in reward-guided behavior.