Nat. Neurosci. 19, 1225–1233 (2016); published online 18 July 2016; corrected after print 29 August 2016

In the version of this article initially published, y-axis labels in Figures 3a,b, 4c, 5d and 6c report the “GluN2B/GluN2A ratio”; this should be “GluN2A/GluN2B ratio.” The error has been corrected in the HTML and PDF versions of the article.