TY - JOUR T1 - P2X-GCaMPs as Versatile Tools for Imaging Extracellular ATP Signaling JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0185-20.2020 VL - 8 IS - 1 SP - ENEURO.0185-20.2020 AU - Matthias Ollivier AU - Juline Beudez AU - Nathalie Linck AU - Thomas Grutter AU - Vincent Compan AU - Francois Rassendren Y1 - 2021/01/01 UR - http://www.eneuro.org/content/8/1/ENEURO.0185-20.2020.abstract N2 - ATP is an extracellular signaling molecule involved in numerous physiological and pathologic processes. However, in situ characterization of the spatiotemporal dynamic of extracellular ATP is still challenging because of the lack of sensor with appropriate specificity, sensitivity, and kinetics. Here, we report the development of biosensors based on the fusion of cation permeable ATP receptors (P2X) to genetically encoded calcium sensors [genetically encoded calcium indicator (GECI)]. By combining the features of P2X receptors with the high signal-to-noise ratio of GECIs, we generated ultrasensitive green and red fluorescent sniffers that detect nanomolar ATP concentrations in situ and also enable the tracking of P2X receptor activity. We provide the proof of concept that these sensors can dynamically track ATP release evoked by depolarization in mouse neurons or by extracellular hypotonicity. Targeting these P2X-based biosensors to diverse cell types should advance our knowledge of extracellular ATP dynamics in vivo. ER -