In vivo two-photon calcium imaging of cortical neurons in neonatal mice

In vivo calcium imaging is essential to elucidate unique synchronous activities observed in the developing brain. Here, we present a protocol to image and analyze activity patterns in neonatal mouse neocortex in a single-cell level. We describe steps for in utero electroporation, cranial window surgery, two-photon imaging, and activity correlation analysis. This protocol facilitates the understanding of neuronal activities and activity-dependent circuit formation during development. For complete details on the use and execution of this protocol, please refer to Mizuno et al. (2014),¹ Mizuno et al. (2018a),² and Mizuno et al. (2018b).³.