Experimental Design.

<p>Experimental design and sample sizes for enriched (EC), isolated (IC), and standard (SC) rats. Drug treatment for Experiment I (fluoxetine, 10 mg/kg, i.p.) and Experiment II (fluoxetine, 20 mg/kg, i.p.) between the locomotor test and the FST was counterbalanced. Experiment III fluoxetine was administered at 20 mg/kg, i.p. Experiment I drug treatment conditions: EC-fluoxetine (n = 12); EC-vehicle (n = 12); IC-fluoxetine (n = 12); IC-vehicle (n = 12). Experiment II drug treatment conditions: EC-fluoxetine (n = 10); EC-vehicle (n = 10); IC-fluoxetine (n = 10); IC-vehicle (n = 10); SC-fluoxetine (n = 10); SC-vehicle (n = 10). Drug treatment conditions for Experiment III were identical to Experiment II. Vehicle-treated and drug-treated rats were housed in the same cages (half vehicle-treated and half drug-treated) for enriched and standard conditions for all three experiments.</p><p>Experimental Design.