1. Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
2. Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St Paul, MN 55108, USA
3. Department of Surgical and Radiological Sciences, University of California at Davis School of Veterinary Medicine, Davis, CA 95616, USA
4. The Institute of Biomedical Engineering, University of Oxford, Oxford, OX3 7DQ, UK