A Birthdating of adult-born neurons prior to recombination was conducted in 24-week old mice. For marker expression analysis, BrdU was injected i.p. every 24 hours for three days (B and C); for morphology analysis, CAG-RFP was stereotactically injected into the DG (D-G). Tamoxifen was applied i.p. every 12 hours for five days. Mice were sacrificed 3dpT and 13dpT. 