Segal S A, Moerschbaecher J M, Thompson D M
Pharmacol Biochem Behav. 1981 Nov;15(5):807-12. doi: 10.1016/0091-3057(81)90026-5.
The effects of phencyclidine, d-amphetamine, and pentobarbital on responding maintained under a multiple fixed-interval (FI) 3-min fixed-ratio (FR) 30 schedule of food presentation were studied in rats. Phencyclidine (0.32-7.5 mg/kg) had a biphasic effect on overall response rate in both components; response rate increased and then decreased as the dose was increased. The FR was slightly more sensitive to the rate-decreasing effects of phencyclidine than the FI. The effects of d-amphetamine (0.1-7.5 mg/kg) on overall response rate were qualitatively similar to those of phencyclidine. The FI tended to be slightly more sensitive than the FR to the rate-increasing effects of d-amphetamine. Pentobarbital (1-18 mg/kg) produced little or no rate-increasing effects in the FR at low doses and decreased FR response rate at higher doses. In the FI, pentobarbital produced small increases in overall rate at intermediate doses while decreasing response rate at higher doses. The FR tended to be more sensitive than the FI to the rate-decreasing effects of pentobarbital. Unlike d-amphetamine and pentobarbital, phencyclidine produced smaller rate-increasing effects when the dose-effect curves were redetermined. Within the FI, the effects of phencyclidine and d-amphetamine on response rate were generally independent of the control rate of responding.
研究了苯环利定、右旋苯丙胺和戊巴比妥对在食物呈现的多重固定间隔（FI）3分钟固定比率（FR）30程序下维持反应的影响。苯环利定（0.32 - 7.5毫克/千克）对两个成分的总体反应率有双相作用；随着剂量增加，反应率先增加后降低。FR对苯环利定的速率降低作用比FI稍敏感。右旋苯丙胺（0.1 - 7.5毫克/千克）对总体反应率的影响在性质上与苯环利定相似。FI对右旋苯丙胺的速率增加作用往往比FR稍敏感。戊巴比妥（1 - 18毫克/千克）在低剂量时对FR几乎没有或没有速率增加作用，在高剂量时降低FR反应率。在FI中，戊巴比妥在中等剂量时使总体速率略有增加，而在高剂量时降低反应率。FR对戊巴比妥的速率降低作用往往比FI更敏感。与右旋苯丙胺和戊巴比妥不同，当重新确定剂量效应曲线时，苯环利定产生的速率增加作用较小。在FI内，苯环利定和右旋苯丙胺对反应率的影响通常与对照反应率无关。
