AUTHOR=Iwai Youichi , Ozawa Katsuya , Yahagi Kazuko , Mishima Tsuneko , Akther Sonam , Vo Camilla Trang , Lee Ashley Bomin , Tanaka Mika , Itohara Shigeyoshi , Hirase Hajime TITLE=Transient Astrocytic Gq Signaling Underlies Remote Memory Enhancement JOURNAL=Frontiers in Neural Circuits VOLUME=15 YEAR=2021 URL=https://www.frontiersin.org/journals/neural-circuits/articles/10.3389/fncir.2021.658343 DOI=10.3389/fncir.2021.658343 ISSN=1662-5110 ABSTRACT=

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. Together, we demonstrate that GPCR-triggered Ca2+ elevation in cortical astrocytes has causal impacts on neuronal activity and behavior.