The Rosa-CAG targeting vector CAG-LSL-VSFP-Butterfly1.2-WPREbGHpA was inserted between exons 1 and 2 of the Gt(ROSA)26Sor locus. The targeting vector was designed with a floxed-STOP cassette (stop codons in all three reading frames linked to synthetic pA-hGHpA-PGKpA), the voltage-sensitive fluorescent protein Butterfly 1.2 coding sequence, a WPRE sequence (to enhance mRNA stability), a BGH polyA. It is a Cre-dependent reporter with a voltage indicator function. (J:219930)