The cultured cells were then infected with 5 mL of Lenti Virus (6 × 108 TU/mL) packed with a tetracycline-controlled red fluorescent protein (RFP) expression sequence per well. The cells with RFP signals were then cultured at a density of 100 000 cells per well on a matrigel-coated coverslip that was placed at the bottom of a well of a 24-well plate for neuronal development for six hours, and then the vector was washed out. RFP expression was induced by addition of doxycycline to the medium after wash-off of the vector. The first day of induction on cover-slip was defined as day-0. Cells were used for morphological and functional analysis from D0.
