Event:

The serotonin system is an evolutionarily conserved neurotransmitter system in the vertebrate brain and has multifaceted roles in behavioral control. Yet, it has been challenging to unravel its downstream targets and its impact on neural dynamics due to its widespread innervation and the complex nature of receptor signaling, calling for a holistic approach. Here, we used a combination of whole-brain imaging of serotonin release, 3D mapping of serotonin receptors and loss-of-function experiments combined with whole-brain neural activity imaging to investigate how the serotonergic system controls adaptive behavior in zebrafish. We identified its downstream targets in the hindbrain motor networks and midbrain sensory networks, and the dualistic effects of serotonin on these networks synergized together to enable visual-motor adaptation. In addition, our recent work on the action of psychedelics revealed how the specific activation of serotonin receptor subtypes rebalances the flow of sensory-motor information across the brain. Overall, our results set conceptual and methodological frameworks for understanding how endogenous serotonin and serotonergic drugs control animal behaviors through the modulation of brain-wide neural dynamics.