title: Evidence for conditioned tolerance of the tail flick reflex.
mesh_terms: D000818:Animals; D003214:Conditioning, Classical / Q000187:drug effects*; D004361:Drug Tolerance; D005260:Female; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009619:Nociceptors / Q000187:drug effects*; D051381:Rats; D012018:Reflex / Q000187:drug effects*; D012684:Sensory Thresholds
chemical_list: D009020:Morphine