Finally, the fact that the Cbr1 resumption to two copies was able to recover the deficit in spatial memory accuracy in Ts1Cje mice without acting significantly on PGE2 quantity or GABAergic over-inhibition suggests that Cbr1 is associated with the memory impairment, but electrophysiological and biochemical phenotypes are independent of Cbr1 and caused by other gene(s) that is included in Ts1Cje but not in Ts1Rhr. This evidence concerns the gene CBR1 and memory impairment.