The transgene expresses an "improved" tetracycline transactivator (itTA) protein under control of a forebrain-specific promoter fragment, comprising 8.5 kb of 5' flanking sequence and 84 base pairs of the first, noncoding exon, of the mouse calcium/calmodulin-dependent protein kinase II alpha (Camk2a) gene, followed by a 1.0 kb DNA fragment containing the first three exons, comprising a neuron restrictive silencer element (NRSE), of the mouse glutamate receptor, ionotropic, NMDA2C (epsilon 3) (Grin2, also called Nr2c) gene. (J:37107, J:96556)