AUTHOR=Yamaguchi Akihiro , Wu Rui , McNulty Paul , Karagyozov Doycho , Mihovilovic Skanata Mirna , Gershow Marc 

TITLE=Multi-neuronal recording in unrestrained animals with all acousto-optic random-access line-scanning two-photon microscopy

JOURNAL=Frontiers in Neuroscience

VOLUME=Volume 17 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2023.1135457

DOI=10.3389/fnins.2023.1135457

ISSN=1662-453X

ABSTRACT=To understand how neural activity enccodes and coordinates behavior, it is desirable to record multi-neuronal activity in freely behaving animals. Imaging in unrestrained animals is challenging, especially for those, like larval \textit{Drosophila melanogaster}, whose brains are deformed by body motion. A previously demonstrated two-photon tracking microscope recorded from individual neurons in freely crawling \textit{Drosophila} larvae but faced limits in multi-neuronal recording. Here we demonstrate a new tracking microscope using acousto-optic deflectors (AODs) and an acoustic GRIN lens (TAG lens) to achieve axially resonant 2D random access scanning, sampling along arbitrarily located axial lines at a line rate of 70 kHz. With a tracking latency of 0.1 ms, this microscope recorded activities of various neurons in moving larval \textit{Drosophila} CNS and VNC including premotor neurons, bilateral visual interneurons, and descending command neurons. This technique can be applied to the existing two-photon microscope to allow for fast 3D tracking and scanning.