The mouse BAC (RP23-381H22) containing Slc1a2 is modified to insert the reporter cassette immediately downstream of the Slc1a2 initiation codon. The reporter construct includes: Optoα1AR (a chimeric molecule of mammalian rhodopsin and Gq-coupled α1 adrenergic receptor), a YFP reporter, an WPRE site, a polyA sequence and an FRT-flanked ampicillin selection cassette. (J:333806)