CortexCAM: A Camera Array Microscope for Cortex-Wide Cellular Imaging in Freely Locomoting Mice

Understanding single-cell neuronal activity across multiple brain regions in the context of ethologically relevant behaviors is a major goal in systems neuroscience. Here we introduce the Cortex Camera Array Microscope (CortexCAM), integrating four miniaturized fluorescence imaging microscopes to simultaneously capture cellular activity from overlapping fields of view spanning over 48 mm² of the dorsal cortex. The CortexCAM is capable of imaging > 9000 individual neurons across the primary and secondary motor, somatosensory, visual, retrosplenial, and association cortices in both hemispheres of the dorsal cortex. The compact architecture of the CortexCAM allows seamless integration into a passive mechanical gantry system to form the mobile CortexCAM. The mobile CortexCAM allows volitional control of the animal's translational motion (x, y) and rotational motion (yaw) in physical spaces. The mobile CortexCAM enables cortex-wide cellular resolution imaging in freely locomoting mice performing alternating choice tasks, as well as during naturalistic social interactions. Thus the CortexCAM allows studying cortex-wide cellular dynamics in ethologically relevant behaviors that cannot be achieved in headfixed preparations.