PT  - JOURNAL ARTICLE
AU  - Madhuvanthi Kannan
AU  - Ganesh Vasan
AU  - Simon Haziza
AU  - Cheng Huang
AU  - Radek Chrapkiewicz
AU  - Junjie Luo
AU  - Jessica A. Cardin
AU  - Mark J. Schnitzer
AU  - Vincent A. Pieribone
TI  - Dual polarity voltage imaging reveals subthreshold dynamics and concurrent spiking patterns of multiple neuron-types
AID  - 10.1101/2021.10.13.463730
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.10.13.463730
4099  - http://biorxiv.org/content/early/2021/10/15/2021.10.13.463730.short
4100  - http://biorxiv.org/content/early/2021/10/15/2021.10.13.463730.full
AB  - Genetically encoded fluorescent voltage indicators are ideally suited to reveal the millisecond-scale interactions among and between distinct, targeted cell populations. However, current indicator families lack the requisite sensitivity for in vivo multipopulation imaging. We describe high-performance green and red sensors, Ace-mNeon2 and VARNAM2, and their reverse response-polarity variants, pAce and pAceR. Our indicators enable 0.4-1 kHz voltage recordings from >50 neurons per field-of-view in awake mice and ∼30-min continuous imaging in flies. Using dual-polarity multiplexed imaging, we uncovered behavioral state-dependent interactions between distinct neocortical subclasses, as well as contributions to hippocampal field potentials from non-overlapping projection neuronal ensembles. By combining three mutually compatible indicators, we demonstrate concurrent triple-population voltage imaging. Our approach will empower investigations of the dynamic interplay between neuronal subclasses at single-spike resolution.One Sentence Summary A new suite of voltage sensors enables simultaneous cellular-resolution activity imaging from multiple, targeted neuron-types in awake animals.Competing Interest StatementMK, GV and VAP are co-inventors on a patent application describing dual-polarity multiplexing; the other authors declare no competing interests.