FEMALE RATS THAT RAPIDLY ACQUIRE A D-AMPHETAMINE DISCRIMINATION GENERALIZE MORE TO D-AMPHETAMINE

Female Long-Evans rats were trained to discriminate a-amphetamine (0.8 mg/kg) vs. saline in a food-reinforced two-lever operant task. Fiftee n rats (fast group) acquired the discrimination rapidly, achieving cri terion (eight correct choices within ten sessions) during the first 10 sessions (mean sessions to criterion = 10.0). The remaining eight rat s (slow group) made at least three errors during the first 10 sessions and required additional drug discrimination training to achieve crite rion (mean sessions to criterion = 15.9). When a rat had completed a m inimum of 30 two-lever discrimination training sessions and, in additi on, provided 10 correct choices within 10 sessions, generalization tes ting with lower doses of d-amphetamine was initiated. The fast group m ade more d-amphetamine-appropriate choices during the generalization t est and generalized more to the 0.2 mg/kg d-amphetamine test dose than did the slow group, though the number of training sessions prior to g eneralization testing was comparable across groups. Results suggest th at when the training drug is easily discriminated, fast learners gener alize more, even when groups receive comparable amounts of training pr ior to generalization testing, and this effect is observed in female r ats.