Models & Assays

Rats may be trained to respond for food reward under a variety of schedules to study factors such as effect of an NCE on motivation for food. Because animals are typically well trained in these tasks, baseline performance can be tightly controlled and performance becomes predictable enabling robust baselines with which to study effects of an NCE.

Effect of lorcaserin (0.3-1 mg/kg SC) pretreatment on behaviours motivated by food made available under a progressive ratio schedule of reinforcement. In this test the response requirement for food reward is increased with each successive reward. The critical measure is the break point, i.e at which response level will the animal cease to work for food. Lorcaserin reduced the break point for food under a progressive schedule of reinforcement consistent with a reduced motivation for food. The effect of lorcaserin wasreversed by the selective 5-HT2C receptor antagonist SB-242084 (SB). Data modified from: Higgins et al (2012) Neuropsychopharmacology 37: 1177-1191.