1. Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
2. Centre for Integrative Physiology, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
3. Anatomy, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK