From whole-brain data to functional circuit models: the zebrafish optomotor response

Summary

Date: 
March 22, 2017 - 1:00pm
Location: 
Northwest 243/ Lunch at 12:45pm
About the Speaker
Name: 
Florian Engert
Speaker Affiliation: 
Harvard University, Molecular and Cellular Biology

Detailed brain-scale descriptions of the sensorimotor transformations underlying
vertebrate behavior remain elusive. In particular, it has been difficult to
distill neural circuits from brain-wide measurements of neural activity. Here,
we use psychophysics and cellular resolution whole-brain functional imaging in
combination with computational approaches to deconstruct the mechanisms
governing the zebrafish optomotor response. We find diverse neural response
types distributed across multiple brain regions and show that to transform
visual motion into action, these regions sequentially integrate eye- and
direction-specific sensory streams, refine representations via interhemispheric
inhibition, and demix locomotor instructions into distinct motor modules. Ultimately,
we develop a quantitative whole-brain model that explains the behavior and
reduces the space of possible synaptic connections into a few critical
dimensions of functional connectivity among identified neural response types.
More generally, our methodology illustrates a flexible paradigm for studying
diverse brain-scale computations and establishes organizational principles for
neural circuits combining multiple sensory streams.