title: Extinction of an appetitive operant response after administration of MSH.
mesh_terms: D000818:Animals; D003216:Conditioning, Operant; D003864:Depression, Chemical; D005108:Extinction, Psychological / Q000187:drug effects*; D006815:Hunger; D007274:Injections, Intraperitoneal; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors
chemical_list: D009074:Melanocyte-Stimulating Hormones