Nature Reviews Neuroscience 13, 308–324 (2012)

In the acknowledgements an omission was made. It should read as follows:

We apologize to the authors of papers we could not include in this Review owing to space limitations. We thank J. Hu and C. M. O'Hare for critical reading of the manuscript. This work was supported by a Wellcome Trust Programme Grant (085314/Z/08/Z) to C.E.H.