A transgenic construct containing cre recombinase under the control of a tetracycline-responsive element (TRE) and a second transgenic construct containing rtTA, under the control of the adrenergic receptor, alpha 2c (Adra2c) were coinjected into fertilized mouse eggs. Extensive transgene expression is found in the claustrum and the dentate gyrus of hippocampus in the brain after tetracyclin/doxycyclin induced. (J:202955)