%0 Journal Article %A Youichi Iwai %A Katsuya Ozawa %A Kazuko Yahagi %A Mika Tanaka %A Shigeyoshi Itohara %A Hajime Hirase %T Transient astrocytic Gq signaling underlies remote memory enhancement %D 2019 %R 10.1101/753095 %J bioRxiv %P 753095 %X Astrocytes elicit transient Ca2+ elevations induced by G protein-coupled receptors (GPCRs), yet their role in vivo remains unknown. To address this, transgenic mice with astrocytic expression of the optogenetic Gq-type GPCR, Optoα1AR, were established, in which transient Ca2+ elevations similar to those in wild type mice were induced by brief blue light illumination. Activation of cortical astrocytes resulted in an adenosine A1 receptor-dependent inhibition of neuronal activity. Moreover, sensory stimulation with astrocytic activation induced long-term depression of sensory evoked response. At the behavioral level, repeated astrocytic activation in the anterior cortex gradually affected novel open field exploratory behavior, and remote memory was enhanced in a novel object recognition task. These effects were blocked by A1 receptor antagonism. On the other hand, compelling evidence for astrocytic Ca2+-induced diameter changes of arteries was not observed. Together, we demonstrate that GPCR-triggered Ca2+ elevation in cortical astrocytes has causal impacts on neuronal activity and behavior. %U https://www.biorxiv.org/content/biorxiv/early/2019/09/02/753095.full.pdf