title: Rolipram forms a potent discriminative stimulus in drug discrimination experiments in rats.
abstract: Long Evans rats were trained to discriminate 0.2 mg/kg IP (+/-)-rolipram from vehicle injection in a food-motivated two-lever operant task. Eight out of nine rats acquired the discrimination after an average of 91 sessions (min 65, max 137). The ED50 of (+/-)-rolipram was 0.06 mg/kg IP. Generalization tests with (-)- and (+)-rolipram showed that the (-)-isomer was 8 times more active than (+)-rolipram with an ED50 of 0.06 and 0.4 mg/kg IP respectively. The phosphodiesterase inhibitor RO 20-1724 partially (83%) generalized to (+/-)-rolipram in doses of 0.6 and 1.0 mg/kg IP. IBMX 5 mg/kg IP showed 63% generalization. Tests with imipramine and the (+)- and (-)-isomer of the noradrenaline uptake inhibitor oxaprotiline suggest that NA-uptake inhibiting drugs do not form an interoceptive cue which is (+/-)-rolipram-like. dbcAMP 12.5 mg/kg SC and 100 mg/kg SC dbcGMP did not generalize to the training drug. The nature of the discriminative stimulus produced by this dose of (+/-)-rolipram in rats remains to be elucidated.
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001921:Brain / Q000187:drug effects*; D003994:Bucladesine / Q000494:pharmacology; D003216:Conditioning, Operant; D003463:Cues; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D004193:Discrimination Learning; D005793:Generalization, Psychological; D011760:Pyrrolidinones / Q000494:pharmacology*; D051381:Rats; D020889:Rolipram
chemical_list: D011760:Pyrrolidinones; D003995:Dibutyryl Cyclic GMP; D003994:Bucladesine; D020889:Rolipram