Time：4:00-5:00 PM，Monday, March 4，2024

    Host：Dr. Kiryl D. Piatkevich, PI of School of Life Sciences

    Venue：E9-109, Yungu Campus

Speaker:

Dr. Misha Ahrens, Senior Group Leader, Janelia Research Campus of the Howard Hughes Medical Institute

Dr. Misha Ahrens received his PhD in Computational Neuroscience in 2009 from the Gatsby Computational Neuroscience Unit of University College London, after studying mathematics and physics at Cambridge University. Following a postdoc at Harvard University in the laboratory of Florian Engert, he started his group at Janelia Research Campus of the Howard Hughes Medical Institute in 2012. Since 2022, he is a Senior Group Leader focusing on systems and computational neuroscience, mechanisms of learning and memory, neuron-glia communication, and brain-body interactions.

Abstract:

As animals interact with their environment, they traverse a variety of internal states such as hunger and fear. These internal states influence spontaneous behavior and responses to new stimuli, and while the neural basis of some of these states have been intensively studied, others remain unclear. To understand the emergence of internal states and their effects on neural circuit computation, we created methods for studying neural computation across the entire brains of larval zebrafish at cellular resolution during behavior. We identified 'giving up' behavior in these animals, or futility-induced passivity, in which an internal state arises from the experience of behavioral futility --failure to achieve a goal-- that eventually triggers passivity. We discovered that astrocytes underlie this behavior: this non-neuronal cell type integrates noradrenergic failure signals and activates behavior-inhibiting neuronal circuits, showing that astrocytes --and not only neurons-- can perform computations. I will present work on the circuit effects of astrocytes, in which we characterized the effects of astrocyte modulation on brain-wide computation, to find that large neuronal circuits are modulated by astrocyte-driven internal states in a way that is coordinated across brain regions. Next, we found that the fast-acting antidepressant ketamine has a profound effect on futility-induced passivity behavior, and that ketamine causes long-lasting plasticity in the norepinephrine-astroglial circuit that might translate to similar effects in mammals. This system holds promise to help screen new antidepressants and characterize their effects on brain-wide circuit dynamics. I will also give an overview of how the data generated by these experimental techniques can benefit from analysis and modeling approaches rooted in statistics and machine learning.

    Contact：

Wenyue Yu: yuwenyue@westlake.edu.cn

School of Life Sciences