Salmon P, Tsaltas E, Gray J A
Department of Psychology, University College London, U.K.
Neuropharmacology. 1989 Mar;28(3):207-10. doi: 10.1016/0028-3908(89)90094-4.
Ten male Sprague-Dawley rats received 6-hydroxydopamine-induced lesions of the dorsal noradrenergic bundle and 10 others underwent control operations. The lesion depleted levels of noradrenaline in the hippocampus to 2% of those in the controls. All rats were then trained for 16 sessions to lever-press in a Skinner box on a variable interval 18 sec schedule of food-reinforcement, then for 42 days on a successive discrimination between periods of variable interval (VI 18 sec) food-reinforcement and periods of extinction. This report describes the effects of chlordiazepoxide (CDP; 5 mg/kg) and propranolol (5 and 10 mg/kg) injected intraperitoneally in both groups on modified ABBA designs after this training. Both drugs increased the response rates in extinction periods. The effect of propranolol was similar at each dose and smaller than that of CDP. Although CDP and propranolol (5 mg/kg) increased variable interval response rates also, this could not account for the effect on extinction response rates. Responding did not differ between the lesioned and control animals and the effects of drugs were similar in each group. It is unlikely that CDP or propranolol release nonrewarded responding by disrupting transmission in the dorsal noradrenergic bundle.
十只雄性斯普拉格-道利大鼠接受了6-羟基多巴胺诱导的背侧去甲肾上腺素能束损伤，另外十只接受了对照手术。损伤使海马体中的去甲肾上腺素水平降至对照组的2%。然后，所有大鼠在斯金纳箱中接受16节训练，按照18秒可变间隔的食物强化时间表按压杠杆，随后在可变间隔（VI 18秒）食物强化期和消退期之间进行连续辨别训练42天。本报告描述了在该训练后，两组大鼠腹腔注射氯氮卓（CDP；5毫克/千克）和普萘洛尔（5毫克/千克和10毫克/千克）对改良ABBA设计的影响。两种药物均提高了消退期的反应率。普萘洛尔各剂量的效果相似，且小于CDP的效果。虽然CDP和普萘洛尔（5毫克/千克）也提高了可变间隔反应率，但这并不能解释对消退反应率的影响。损伤组和对照组动物的反应没有差异，且每组中药物的效果相似。氯氮卓或普萘洛尔不太可能通过破坏背侧去甲肾上腺素能束的传递来释放无奖励反应。
