title: Antagonism by methysergide and cinanserin of the antinociceptive action of morphine administered into the periaqueductal gray.
mesh_terms: D000818:Animals; D001931:Brain Mapping; D002535:Cerebral Aqueduct / Q000187:drug effects*; D002928:Cinanserin / Q000494:pharmacology*; D002934:Cinnamates / Q000494:pharmacology*; D008297:Male; D008784:Methysergide / Q000494:pharmacology*; D009020:Morphine / Q000037:antagonists & inhibitors*; D010146:Pain; D051381:Rats; D012701:Serotonin / Q000502:physiology
chemical_list: D002934:Cinnamates; D012701:Serotonin; D009020:Morphine; D002928:Cinanserin; D008784:Methysergide