Abstract
We recently established a simple and versatile adeno-associated virus (AAV) induction approach that enables dense (>90% labeled neurons) and cortical-wide Ca(2+) sensor expression. Here, we describe the stepwise protocol for neonatal AAV injection of a Ca(2+) sensor. We also detail the steps for subsequent craniotomy to generate a chronic cranial window, followed by wide-field two-photon Ca(2+) imaging in an awake mouse. This protocol serves as an alternative to the use of transgenic animals and offers translatable options for cortical-wide experiments. For complete details on the use and execution of this protocol, please refer to Ota et al. (2021).