Fast 3D Imaging of Spine, Dendritic, and Neuronal Assemblies in Behaving Animals

• Published in: Neuron (Cambridge, Mass.) Vol. 92; no. 4; pp. 723 - 738
• Main Authors: Szalay, Gergely, Judák, Linda, Katona, Gergely, Ócsai, Katalin, Juhász, Gábor, Veress, Máté, Szadai, Zoltán, Fehér, András, Tompa, Tamás, Chiovini, Balázs, Maák, Pál, Rózsa, Balázs
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 23.11.2016; Elsevier Limited; Cell Press
• Subjects: Animals; Behavior, Animal; Calcium; Cell Body - ultrastructure; Dendrites - ultrastructure; Dendritic spines; Dendritic Spines - ultrastructure; Imaging, Three-Dimensional; Methods; Mice; Microscopy; Neurons - ultrastructure; NeuroResource; Optical Imaging - methods; Scanning; Signal-To-Noise Ratio
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2016.10.002

Understanding neural computation requires methods such as 3D acousto-optical (AO) scanning that can simultaneously read out neural activity on both the somatic and dendritic scales. AO point scanning can increase measurement speed and signal-to-noise ratio (SNR) by several orders of magnitude, but high optical resolution requires long point-to-point switching time, which limits imaging capability. Here we present a novel technology, 3D DRIFT AO scanning, which can extend each scanning point to small 3D lines, surfaces, or volume elements for flexible and fast imaging of complex structures simultaneously in multiple locations. Our method was demonstrated by fast 3D recording of over 150 dendritic spines with 3D lines, over 100 somata with squares and cubes, or multiple spiny dendritic segments with surface and volume elements, including in behaving animals. Finally, a 4-fold improvement in total excitation efficiency resulted in about 500 × 500 × 650 μm scanning volume with genetically encoded calcium indicators (GECIs). •3D DRIFT AO scanning can extend each point to 3D lines, surfaces, or volume elements•Retained spatial information is used for post hoc movement correction of signals•Chessboard; snake; multi-cube; multi-3D line; and multi-layer, multi-frame scanning•Improved excitation efficiency for large 3D scanning volume with GECIs 3D DRIFT acousto-optical microscopy designed by Szalay et al. allows confined two-photon scanning of multiple 3D regions of interest. Activity of hundreds of neurons or multiple dendritic processes can be measured simultaneously in large cortical volumes of behaving animals.