Ultrafast Two-Photon Imaging of a High-Gain Voltage Indicator in Awake Behaving Mice.
Villette V, Chavarha M, Dimov IK, Bradley J, [...], Mathieu B, [...], Dieudonné S, Lin MZ.
Authors
Vincent Villette, Mariya Chavarha, Ivan K.Dimov, Jonathan Bradley, Lagnajeet Pradhan, Benjamin Mathieu, Stephen W. Evans, Simon Chamberland, Dongqing Shi, Renzhi Yang, Benjamin B. Kim, Annick Ayon, Abdelali Jalil, François St-Pierre, Mark J.Schnitzer, GuoqiangBi, KatalinToth, Jun Ding, Michael Z. Lin
In Brief
The genetically encoded voltage indicator, ASAP3, provides improved voltage responses and activation kinetics that enable single-trial tracking of action potentials and subthreshold events with subcellular resolution deep in the mouse brain during behavioral tasks when imaged with ULoVE, a kilohertz-rate twophoton sampling method with increased stability and sensitivity.
Abstract
Optical interrogation of voltage in deep brain locations with cellular resolution would be immensely useful for understanding how neuronal circuits process information. Here, we report ASAP3, a genetically encoded voltage indicator with 51% fluorescence modulation by physiological voltages, submillisecond activation kinetics, and full responsivity under two-photon excitation. We also introduce an ultrafast local volume excitation (ULoVE) method for kilohertz-rate two-photon sampling in vivo with increased stability and sensitivity. Combining a soma-targeted ASAP3 variant and ULoVE, we show single-trial tracking of spikes and subthreshold events for minutes in deep locations, with subcellular resolution and with repeated sampling over days. In the visual cortex, we use soma-targeted ASAP3 to illustrate cell-type-dependent subthreshold modulation by locomotion. Thus, ASAP3 and ULoVE enable high-speed optical recording of electrical activity in genetically defined neurons at deep locations during awake behavior.
Cell. 2019 Dec 12 ;179(7):1590-1608.e23. doi : 10.1016/j.cell.2019.11.004.
