title: Knocking on Kleitman's door: the view from 50 years later.
mesh_terms: D001921:Brain / Q000502:physiology; D004569:Electroencephalography; D049673:History, 20th Century; D049674:History, 21st Century; D009474:Neurons / Q000502:physiology; D010827:Physiology / Q000266:history*; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000266:history*; D012895:Sleep, REM / Q000502:physiology; D014481:United States