Brain-wide multi-fiber recording of neuronal activity in freely moving mice.

While brain regions function in coordination to mediate diverse behaviors, techniques allowing simultaneous monitoring of many deep brain regions remain limited. Here, we present a multi-fiber recording protocol that enables simultaneous recording of fluorescence signals from multiple brain regions in freely behaving mice. We describe steps for assembling a multi-fiber array and patch cord, implantation, and recording. We then detail procedures for data extraction and visualization. This protocol enables a comprehensive view of the neural activity at the network level. For complete details on the use and execution of this protocol, please refer to Guo et al..