title: Acquisition and extinction of operant responding for intravenous injections of fentanyl in the rat.
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D005108:Extinction, Psychological; D005283:Fentanyl / Q000008:administration & dosage* / Q000494:pharmacology; D007275:Injections, Intravenous; D008297:Male; D051381:Rats; D012646:Self Administration
chemical_list: D005283:Fentanyl