Adult female C57BL/6 mice (P42) housed under standard conditions were anaesthetized and concentrated retroviruses were stereotaxically injected into the dentate gyrus as previously described (Duan et al., 2007). P10 pups (C57BL/6 or CD1) were anaesthetized and retroviruses were stereotaxically injected at 2 sites (from Bregma in mm): anterioposterior = − 1.8, lateral = ± 1.8, ventral = 1.5. All animal procedures were performed in accordance with the protocol approved by the Institutional Animal Care and Use Committee.
