Nature Communications 6: Article number: 6756 (2015); Published: 9 April 2015; Updated: 21 August 2015.

The affiliation details for Lin Xu and Xintian Hu are incorrect in this article. The correct affiliation for these authors is given below. Kunming Institute of Zoology, CAS Center for Excellence in Brain Science, Chinese Academy of Sciences, Kunming 650223, China.