About the Authors
Department of Biochemistry, University of Zürich, Zürich, Switzerland
Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
The authors have declared that no competing interests exist.
The author(s) have made the following declarations about their contributions: Conceived and designed the experiments: RD IZ LGS. Performed the experiments: IZ CB AM. Analyzed the data: RD IZ CB LGS AM. Wrote the paper: RD IZ LGS AM CB.