Two-photon all-optical neurophysiology for the dissection of larval zebrafish brain functional and effective connectivity

Year: 2024

Authors: Turrini L., Ricci P., Sorelli M., de Vito G., Marchetti M., Vanzi F., Pavone FS.

Autors Affiliation: CNR, Natl Inst Opt, Natl Res Council, INO, Sesto Fiorentino, Italy; European Lab Nonlinear Spect LENS, Sesto Fiorentino, Italy; Univ Florence, Dept Phys & Astron, Sesto Fiorentino, Italy; Univ Florence, Dept Neurosci Psychol Drug Res & Child Hlth, Florence, Italy; L4T Light4Tech, Florence, Italy; Univ Florence, Dept Biol, Sesto Fiorentino, Italy; Univ Barcelona, Dept Appl Phys, Barcelona, Spain.

Abstract: One of the most audacious goals of modern neuroscience is unraveling the complex web of causal relations underlying the activity of neuronal populations on a whole-brain scale. This endeavor, which was prohibitive only a couple of decades ago, has recently become within reach owing to the advancements in optical methods and the advent of genetically encoded indicators/actuators. These techniques, applied to the translucent larval zebrafish have enabled recording and manipulation of the activity of extensive neuronal populations spanning the entire vertebrate brain. Here, we present a custom two-photon optical system that couples light-sheet imaging and 3D excitation with acousto-optic deflectors for simultaneous high-speed volumetric recording and optogenetic stimulation. By employing a zebrafish line with pan-neuronal expression of both the calcium reporter GCaMP6s and the red-shifted opsin ReaChR, we implemented a crosstalk-free, noninvasive all-optical approach and applied it to reconstruct the functional and effective connectivity of the left habenula. Two-photon light-sheet imaging and AOD-based optogenetic stimulation enable the detailed reconstruction of the left habenula functional connectivity in translucent larval zebrafish, offering a promising avenue towards brain function unraveling.

Journal/Review: COMMUNICATIONS BIOLOGY

Volume: 7 (1)      Pages from: 1261-1  to: 1261-16

More Information: We thank Dr. Ludovico Silvestri (University of Florence), Dr. Leonardo Sacconi (INO-CNR), and Domenico Alfieri (Light4Tech) for fruitful discussions regarding AOD implementation. We thank Dorotea Nardini (Universit y of Florence) for the helpful discussion about error propagation theory. We thank Lizzy Griffiths for the larval zebrafish drawing used in Supplementary Fig. 1b. This project was funded by: European Union’s NextGenerationEU Program with the I-PHOQS Infrastructure [IR0000016, ID D2B8D520, CUP B53C22001750006] Integrated infrastructure initiative in Photonic and Quantum Sciences and the Italian Ministry for University and Research in the framework of the Advanced Light Microscopy Italian Node of Euro-Bioimaging ERIC, and the Bank Foundation Fondazione Cassa di Risparmio di Firenze with grant Human Brain Optical Mapping.
KeyWords: Habenular Nuclei; Resolution; Electrophysiology; Optogenetics; Neurons; Manipulation; Microscopy; Position; Behavior; Deep
DOI: 10.1038/s42003-024-06731-3