1. J. E. Sherin, Department of Neurology, Harvard Medical School, Beth Israel Hospital, Boston, MA 02215; Program in Neuroscience, Harvard Medical School, Boston, MA 02115; and Committee on Neurobiology, University of Chicago, Chicago, IL 60637, USA.
2. P. J. Shiromani and R. W. McCarley, Program in Neuroscience, Harvard Medical School, Boston, MA 02115, and Department of Psychiatry, Harvard Medical School, Brockton Veterans Administration Hospital, Brockton, MA 02401, USA.
3. C. B. Saper, Department of Neurology, Harvard Medical School, Beth Israel Hospital, Boston, MA 02215, and Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA.