Full-optical stimulation and readout of neuronal activity during optogenetically-evoked movements in awake mice

In the last few years, optogenetic tools and optical functional indicators are increasingly used together to perform simultaneous manipulation and recording of neuronal activity. Nevertheless, this method has still some limitations mainly due to the spectral cross-talk between optogenetic actuators and functional sensors [1;2]. To address this issue, red variants of genetically encoded calcium indicators (red-GECIs) have been recently developed [3;4]. The main goal of this project is to develop a full-optical system that allows effective interrogation of brain circuits. To this aim, we combined a red-shifted calcium indicator (jRCaMP1a), with the most common blue-light activated opsin, Channelrhodopsin II (ChR2). The results presented here show: (I) extended expression of the full-optical system that covers all the motor areas, (II) functional correlation between the laser power and the evoked neuronal activity, (III) segregation of the cortical functional areas of two different forelimb evoked movements. The future perspective of this project concerns the study of the functional areas correlation during optogenetically-evoked forelimb complex movements.