Melanopsin for precise optogenetic activation of astrocyte‐neuron networks. Issue 5 (11th January 2019)

• Record Type: Journal Article
• Authors: Mederos, Sara; Hernández‐Vivanco, Alicia; Ramírez‐Franco, Jorge; Martín‐Fernández, Mario; Navarrete, Marta; Yang, Aimei; Boyden, Edward S.; Perea, Gertrudis
• Is Part Of: Glia. Volume 67:Issue 5(2019)
• Page Start: 915
• Page End: 934
• Publication Date: 2019-01-11
• Subjects: astrocytes -- optogenetics -- melanopsin -- neuron–glia interactions -- synaptic plasticity; Neuroglia -- Periodicals; Neurology -- Periodicals; 611.0188
• DOI: 10.1002/glia.23580
• Languages: English
• ISSNs: 0894-1491

Abstract

Abstract: Optogenetics has been widely expanded to enhance or suppress neuronal activity and it has been recently applied to glial cells. Here, we have used a new approach based on selective expression of melanopsin, a G‐protein‐coupled photopigment, in astrocytes to trigger Ca 2+ signaling. Using the genetically encoded Ca 2+ indicator GCaMP6f and two‐photon imaging, we show that melanopsin is both competent to stimulate robust IP3‐dependent Ca 2+ signals in astrocyte fine processes, and to evoke an ATP/Adenosine‐dependent transient boost of hippocampal excitatory synaptic transmission. Additionally, under low‐frequency light stimulation conditions, melanopsin‐transfected astrocytes can trigger long‐term synaptic changes. In vivo, melanopsin‐astrocyte activation enhances episodic‐like memory, suggesting melanopsin as an optical tool that could recapitulate the wide range of regulatory actions of astrocytes on neuronal networks in behaving animals. These results describe a novel approach using melanopsin as a precise trigger for astrocytes that mimics their endogenous G‐protein signaling pathways, and present melanopsin as a valuable optical tool for neuron–glia studies. Main points: Melanopsin, a mammalian G‐protein‐coupled photopigment, engages endogenous the IP3 pathway and intracellular Ca2+ signaling in astrocytes. By releasing ATP/Ado, melanopsin‐astrocytes differently impact synaptic plasticity enhance cognitive functions.