To determine the basal locomotor behavior of young (P20–26, the age also used for electrophysiology) GluA1−/− and GluA1+/+ mice, a 30-min locomotor activity test was run in exactly the same conditions as the place conditioning described above. As in the adult mice, locomotor activity of the young GluA1−/− mice (115.0±6.3 m) was greater than that of GluA1+/+ mice (48.2±2.6 m) (genotype effect, F1,31 = 98.61, p<0.001). Young GluA1−/− mice were, thus, moving 2.40 times more than GluA1+/+ mice, the ratio being almost identical to that in adults (2.43 times more) treated with saline during the first conditioning trial. No significant effect of sex or genotype×sex interaction was found (p>0.05).
