[1] Lundbeck Res USA Inc, Synapt Transmiss, Paramus, NJ 07652 USA
[2] Pfizer Inc, Neurosci Res Unit, Global Res & Dev, Groton, CT 06340 USA
[3] Merck & Co Inc, Pain & Migraine, West Point, PA 19486 USA
[4] Univ Wisconsin, Dept Psychol, Madison, WI 53706 USA