Correspondence: Dr TH Murphy, Kinsmen Laboratory of Neurological Research, University of British Columbia, 2255 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada. E-mail: thmurphy@mail.ubc.ca This work was supported by a Canadian Institutes of Health Research Operating Grant MOP-12675, a Heart and Stroke Foundation of BC and Yukon grant in aid, and a Heart and Stroke Foundation of Canada grant in aid.
