This model conditionally overexpresses the GCaMP6f gene in the Rosa26 safe harbor in the mouse genome and is a Cre-dependent fluorescent calcium indicator strain. The presence of a loxP-Stop-loxP element upstream of the GCaMP6f gene expression element blocks GCaMP6f expression. Upon mating with Cre mice, Cre-mediated sequence recombination between loxP sites results in the deletion of the Stop element in the offspring mice, and bright EGFP fluorescence is observed following calcium binding (e.g. neuronal activation).