Figure 2 (IMAGE) Tohoku University Caption Optogenetic alkalinization of habenular astrocytes results in the reduction of anxiety. (A) Archaerhodopsin-T (ArchT) is a light-activated outward proton pump. Photoactivation of ArchT expressed in cell membranes results in intracellular alkalinization. ArchT was selectively expressed in astrocytes and the optical fiber placed in the habenula was used for photoactivation of ArchT. When the mouse was placed in an anxiogenic, all-marble cage environment, theta-band neuronal activity was detected. Photoactivation of the ArchT in the habenular astrocytes led to the reduction of the theta-band. (B) Mice normally prefer a dark room with comfortable bedding. When the mouse was placed in a two-way chamber with a dark room and a bright room with an all-marble floor, the mouse tended to stay in the dark room. However, when the ArchT in the habenular astrocytes were photoactivated, the mouse ventured to the bright room and traveled more in the bright room. These results suggest that when the acidic reaction of the habenular astrocytes is countered by optogenetic alkalinization, anxiety can be reduced. Credit Wanqin Tan, Ko Matsui. Usage Restrictions Reporters may use freely these materials in news coverage with appropriate credit information. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.