Whole-central nervous system functional imaging in larval Drosophila.

William C Lemon,Jeremy Freeman,Burkhard Höckendorf,Philipp J Keller,Stefan R Pulver,Kristin Branson,Katie Mcdole

doi:10.1038/ncomms8924

William C Lemon, Jeremy Freeman + Show 5 more

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https://doi.org/10.1038/ncomms8924

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Abstract

Understanding how the brain works in tight concert with the rest of the central nervous system (CNS) hinges upon knowledge of coordinated activity patterns across the whole CNS. We present a method for measuring activity in an entire, non-transparent CNS with high spatiotemporal resolution. We combine a light-sheet microscope capable of simultaneous multi-view imaging at volumetric speeds 25-fold faster than the state-of-the-art, a whole-CNS imaging assay for the isolated Drosophila larval CNS and a computational framework for analysing multi-view, whole-CNS calcium imaging data. We image both brain and ventral nerve cord, covering the entire CNS at 2 or 5 Hz with two- or one-photon excitation, respectively. By mapping network activity during fictive behaviours and quantitatively comparing high-resolution whole-CNS activity maps across individuals, we predict functional connections between CNS regions and reveal neurons in the brain that identify type and temporal state of motor programs executed in the ventral nerve cord.

Highlights

Understanding how the brain works in tight concert with the rest of the central nervous system (CNS) hinges upon knowledge of coordinated activity patterns across the whole CNS
Would the ability to simultaneously record activity everywhere within an entire central nervous system (CNS) enable measurements of large-scale network dynamics and provide a way to discover and map functional connections between remote CNS regions[14]; whole-CNS functional imaging, that is, simultaneous imaging of both brain and nerve cord, would afford researchers with opportunities to comprehensively record from motor circuitry while simultaneously imaging activity across the brain
The imaging framework described here represents the first method capable of recording neural activity at near cellular resolution throughout the CNS of a higher invertebrate. By applying this framework to the Drosophila larval CNS, we found that representations of fictive locomotor activity are present in presumed higher-order centres at both a regional level and at the level of individual neurons, and that these representations change depending on the mode of fictive locomotion

Summary

Introduction

Understanding how the brain works in tight concert with the rest of the central nervous system (CNS) hinges upon knowledge of coordinated activity patterns across the whole CNS. Would the ability to simultaneously record activity everywhere within an entire central nervous system (CNS) enable measurements of large-scale network dynamics and provide a way to discover and map functional connections between remote CNS regions[14]; whole-CNS functional imaging, that is, simultaneous imaging of both brain and nerve cord, would afford researchers with opportunities to comprehensively record from motor circuitry while simultaneously imaging activity across the brain. Such a method would make it possible to systematically study how brain and nerve cord interact to generate behaviour. Our methodological framework combines three novel components, each of which is designed to overcome one of the three limitations

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