McMillan D.E., Hardwick W.C.
Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205-7199, USA.
Behav Pharmacol. 1996 May;7(3):285-293.
Pigeons were trained to discriminate 5mg/kg pentobarbital from saline under several multiple fixed-ratio fixed-interval schedules of food presentation. The following schedules were studied: multiple fixed-ratio 40 fixed-interval 18s (mult FR40 FI18), mult FR10 FI18s, mult FR10 FI180s and mult FR90 FI10s. After responding stabilized under each multiple schedule, generalization curves were determined for pentobarbital, amobarbital, diazepam, phencyclidine and d-amphetamine. Pentobarbital generated dose-dependent increases in responding under all schedule components; however, there was more responding on the drug key after low doses of pentobarbital under FI components than under FR components, except for the FR90 component of the mult FR90 FI10 schedule. This tendency for more responding on the drug key after low doses of pentobarbital under FI components than under FR components generally was observed for low doses of all of the drugs. Examination of data from individual subjects revealed that there was a greater tendency for birds to distribute responding on both keys (mixed responding) under FI components than under FR components, where responding after each dose was confined largely to one of the two response keys. Analysis of local rates of responding within the FI component of the schedules showed that responding under the FI components developed the typical FI scallop at all FI-component durations. These data suggest that FI schedules with values between 10 and 180s generate similar dose-effect curves with higher rates of responding on the drug key after low doses of drugs than under FR schedules with low response requirements; however, under schedules with higher FR requirements, the dose-effect curves for some drugs begin to look more like those under FI schedules.
在几种食物呈现的多重固定比率-固定间隔时间表下，训练鸽子区分5mg/kg戊巴比妥和生理盐水。研究了以下时间表：多重固定比率40-固定间隔18秒（多重FR40 FI18）、多重FR10 FI18秒、多重FR10 FI180秒和多重FR90 FI10秒。在每种多重时间表下反应稳定后，确定戊巴比妥、异戊巴比妥、地西泮、苯环己哌啶和右旋苯丙胺的泛化曲线。戊巴比妥在所有时间表成分下均产生剂量依赖性的反应增加；然而，除了多重FR90 FI10时间表的FR90成分外，在FI成分下低剂量戊巴比妥后，药物键上的反应比FR成分下更多。对于所有药物的低剂量，通常在FI成分下低剂量戊巴比妥后药物键上的反应比FR成分下更多。对个体受试者数据的检查显示，与FR成分相比，鸟类在FI成分下更倾向于在两个键上分布反应（混合反应），在FR成分下，每次给药后的反应主要局限于两个反应键之一。对时间表FI成分内局部反应率的分析表明，在所有FI成分持续时间下，FI成分下的反应都形成了典型的FI扇贝形。这些数据表明，10至180秒之间的FI时间表产生相似的剂量效应曲线，与低反应要求的FR时间表相比，低剂量药物后药物键上的反应率更高；然而，在具有更高FR要求的时间表下，某些药物的剂量效应曲线开始看起来更类似于FI时间表下的曲线。
