Topic: multi-fiber photometry

Animal behavior is controlled through the coordinated action of multiple learning systems in the brain. One of these systems, the basal ganglia, instantiates a reinforcement learning (RL) algorithm in which dopamine (DA) neurons transmit reward prediction error (RPE) signals---the difference between actual and expected rewards---to enable value learning via cortico-striatal plasticity. Recent studies have highlighted two novel aspects: first, that RPE signals from midbrain DA neurons can encode entire reward distributions through a distributional RL algorithm that mirrors cutting-edge machine

Appropriate risk evaluation is essential for survival in complex, uncertain environments. Confronted with choosing between certain (safe) and uncertain (risky) options, animals show strong preference for either option consistently across extended time periods. How such risk preference is encoded in the brain remains elusive. A candidate region is the lateral habenula (LHb), which is prominently involved in various value-guided behaviors. Here, using a balanced two-alternative choice task and longitudinal two-photon calcium imaging, we find LHb neurons with risk-preference-selective activity re