Neisewander J L, Bardo M T
Department of Psychology, University of Kentucky, Lexington 40506.
Psychopharmacology (Berl). 1987;93(3):314-9. doi: 10.1007/BF00187249.
The present experiments assessed whether morphine-conditioned hyperactivity could be attenuated by either the opiate antagonist naloxone or the dopamine antagonist pimozide. Both of these antagonists were shown to block the unconditioned hyperactivity induced by 2 mg/kg morphine (Experiment 1). Rats were then conditioned by pairing this dose of morphine repeatedly with a distinctive environment (Experiment 2). Following several drug-environment pairings, rats displayed a hyperactive conditioned response (CR) when exposed to the environment in the absence of the drug. CR expression was counteracted by 1 mg/kg naloxone and was attenuated by pimozide (0.25, 0.33, and 0.4 mg/kg) in a dose-related manner. These findings suggest that the unconditioned and conditioned hyperactive responses produced by morphine may involve similar neuropharmacologic substrates.
本实验评估了阿片拮抗剂纳洛酮或多巴胺拮抗剂匹莫齐特是否能减弱吗啡条件性多动。结果表明，这两种拮抗剂均可阻断2mg/kg吗啡诱导的非条件性多动（实验1）。然后，通过将该剂量的吗啡与一个独特环境反复配对对大鼠进行条件化训练（实验2）。经过几次药物-环境配对后，大鼠在无药物情况下暴露于该环境时会表现出多动的条件反应（CR）。1mg/kg纳洛酮可抵消CR的表达，匹莫齐特（0.25、0.33和0.4mg/kg）则以剂量相关的方式减弱CR的表达。这些发现表明，吗啡产生的非条件性和条件性多动反应可能涉及相似的神经药理学底物。
