Date of Acceptance: 31/08/2014 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Acknowledgements: We thank Dr. Joseph W. Lynch for sharing the IVMR plasmid, and Dr. Lisa M. Monteggia for sharing the AAV2-Cre plasmid. Rosa-CAG targeting vector was obtained from Addgenes. This work was supported by the Key State Research Program from Ministry of Science and Technology of China (2011CB510005, 2012CB966900, 2013CB835103), National Natural Science Foundation of China (81221001, 81200692, 81101026, 31100788, 31271182, 31030034, 91232724), Science and Technology Commission of Shanghai Municipality (12XD1404800), Shanghai Pujiang Program (12PJ1408800), Key Disciplines Group Construction Project of Pudong Health Bureau of Shanghai (PWZxq2014-04) and Sino-UK Higher Education Research Partnership for PhD Studies.