Slawecki C J, Samson H H
Department of Physiology and Pharmacology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27101, USA.
Pharmacol Biochem Behav. 1996 Jul;54(3):595-600. doi: 10.1016/0091-3057(95)02287-2.
A multiple schedule (Mult FR 10 VI 30") was employed to examine the interaction of reinforcement schedule and food restriction on amphetamine's effects on lever pressing behavior. High response rates were observed in fixed ratio (FR) 10 components. Significantly lower response rates were observed under the variable interval (VI) 30" schedule. In the nonrestricted feeding condition, significant decreases in high rate FR 10 responding occurred after administration of 1.0 mg/kg amphetamine while lower rates under the same schedule were increased by 0.30 and 1.0 mg/kg amphetamine. In contrast, VI 30" responding was minimally effected at any amphetamine dose. Food restriction resulted in significant increases in responding in both schedule components. Under food restriction, significant decreases in responding were observed only in the FR 10 components at the highest amphetamine dose. The data indicate that amphetamine produced rate-convergent effects and the susceptibility of the animal to these effects was dependent on the schedule of reinforcement and food restriction.
采用多重强化程序（固定比率10次强化后可变间隔30秒）来研究强化程序和食物限制对苯丙胺影响杠杆按压行为的交互作用。在固定比率（FR）10次强化的部分观察到高反应率。在可变间隔（VI）30秒的程序下观察到明显较低的反应率。在非限制进食条件下，给予1.0毫克/千克苯丙胺后，FR 10次强化中高反应率显著下降，而在相同程序下较低的反应率在给予0.30和1.0毫克/千克苯丙胺后有所增加。相比之下，在任何苯丙胺剂量下，VI 30秒的反应受影响最小。食物限制导致两个强化程序部分的反应都显著增加。在食物限制条件下，仅在最高苯丙胺剂量时，FR 10次强化部分的反应才显著下降。数据表明苯丙胺产生了速率收敛效应，并且动物对这些效应的敏感性取决于强化程序和食物限制。
