Ford K E, Fowler S C, Nail G L
Pharmacol Biochem Behav. 1979 Aug;11(2):239-41. doi: 10.1016/0091-3057(79)90021-2.
Rats responded under a FR20 schedule of water reinforcement by paw-pressing a silent, isometric, force-sensing manipulandum. Two seven-animal groups differed in terms of the force requirement for reinforcer delivery, i.e., a low-force condition (4-g requirement for reinforcer delivery) or a high-force condition (32-g requirement for reinforcer delivery). Oral dose ranges of chlorpromazine (1.0, 3.0, 9.0 mg/kg) and clozapine (2.5, 5.0, 10.0 mg/kg) were evaluated for their effects on intensitive measures of response (i.e., peak force and duration), in addition to the conventional rate measure. Peak force, duration, and rate of response were recorded with a laboratory computer system. Conjoint examination of these three dependent variables revealed that clozapine, a new anti-psychotic agent which produces virtially no extrapyramidal side effects in man, affected FR responding in the same way as did chlorpromazine. More specifically, response rate and peak force declined as a function of dose for each drug. Duration of response tended to be increased at the highest dose for both clozapine and chlorpromazine, but this effect was limited primarily to the high-force condition.
大鼠通过按压一个静音、等距、力敏操作手柄，在每20次按压获得一次水强化的固定比率（FR20）程序下做出反应。两个七只动物的组在获得强化物所需的力的要求上有所不同，即低力条件（获得强化物需4克力的要求）或高力条件（获得强化物需32克力的要求）。除了传统的反应速率测量外，还评估了氯丙嗪（1.0、3.0、9.0毫克/千克）和氯氮平（2.5、5.0、10.0毫克/千克）的口服剂量范围对反应强度测量指标（即峰值力和持续时间）的影响。反应的峰值力、持续时间和速率由实验室计算机系统记录。对这三个因变量的联合检查显示，氯氮平作为一种在人体几乎不产生锥体外系副作用的新型抗精神病药物，对固定比率反应的影响与氯丙嗪相同。更具体地说，每种药物的反应速率和峰值力都随剂量增加而下降。氯氮平和氯丙嗪在最高剂量时反应持续时间都有增加的趋势，但这种影响主要限于高力条件。
