Time: 14:00-15:30 on Mon.,Apr.7, 2025

Venue: E109,Biomedicine Hall

Speaker: Dr. Misha Ahrens

Host: Dr. Guoqiang Yu

Title: Whole-brain and whole-body computations for behavior and physiology

Abstract：

Neurons Neural computation underlying sensation, information accumulation, memory, decisions, and actions are distributed across many brain areas that exhibit intricate local and long-range connectivity. Understanding the brain’s global dynamics may depend on observing and modeling the system as a whole. To study neuronal dynamics simultaneously across all brain regions at cellular resolution, we developed a whole-brain light-sheet imaging system for larval zebrafish as they behave in virtual reality environments. As the animals swim through virtual arenas, they evaluate the outcomes of their actions and, and as they learn from those, adjust their future actions. Whole-brain imaging and neuronal perturbations during such behavior revealed a role for multiple neuromodulatory systems and non-neuronal cells called radial astrocytes in integrating behavioral outcomes to drive motor learning and adaptive changes in behavioral states. To study longer-term learning, we developed a robotic system where fish learn from interactions with virtual agents, in which we discovered that learning occurs through noradrenergic reinforcement signals impinging on forebrain dynamics. To explain such brain dynamics through neuronal connectivity, we developed simultaneous functional imaging and whole-brain connectomics, allowing for novel computational analyses of structure-function relationships. Finally, since bidirectional connections between the brain and organ systems form an integral component of neural computation, we expanded into whole-body imaging to study the relationship between brain dynamics and organ physiology at the scale of the entire organism.

Biography：

Misha Ahrens did his undergraduate in mathematics and theoretical physics at Cambridge University, and his PhD in computational neuroscience at the Gatsby Computational Neuroscience Unit of University College London. He incorporated experimental approaches as a Sir Henry Wellcome Postdoctoral Scholar working at Havard University on zebrafish systems neuroscience. In 2012 he started a laboratory at HHMI Janelia Research Campus. In 2019 he was awarded the Eric Kandel Young Neuroscientists Prize, and in 2024 the Frontiers of Science Award from the International Congress of Basic Science (Beijing). He is currently a Senior Group Leader working on whole-brain systems neuroscience, neuron-glia interactions, neuroengineering, and body-brain interactions.