title: Autoanalgesia: behaviorally activated antinociception.
mesh_terms: D000698:Analgesia; D000818:Animals; D001921:Brain / Q000378:metabolism; D003214:Conditioning, Classical / Q000502:physiology*; D005048:Etorphine / Q000378:metabolism; D005239:Fear / Q000502:physiology; D008297:Male; D051381:Rats; D011930:Reaction Time
chemical_list: D005048:Etorphine