Dose-dependent effects of heroin on memory in two inbred strains of mice.
Heroin was administered to DBA/2 and C57BL/6 mice, trained in the five-choice Yerkes-Thompson-Bryant-Bovet-Nitti apparatus for pattern discrimination, in two sets of experiments. In a first set, pretrial administrations of heroin (0.1, 0.25, or 0.5 mg/kg) improved performance in both strains. In a second set, heroin (0.5 mg/kg) immediately following each training session were followed by performance improvements in both strains, while the performance of C57 mice was improved and that of the DBA mice was impaired by 5 mg/kg of opiate. No effect was evident in this set of experiments when heroin was injected 2 h after each session, suggesting that effects of the pretrial treatments were due to influences of the opiate on the consolidation processes of the strains tested.
D000818:Animals; D004193:Discrimination Learning / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D003932:Heroin / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D013045:Species Specificity
D003932:Heroin