title: Pain perception, analgesia and hyperalgesia.
mesh_terms: D000698:Analgesia; D000818:Animals; D006801:Humans; D006930:Hyperalgesia / Q000139:chemically induced*; D006941:Hyperesthesia / Q000139:chemically induced*; D009020:Morphine / Q000494:pharmacology; D009619:Nociceptors / Q000502:physiology; D010146:Pain; D051381:Rats
chemical_list: D009020:Morphine