Particularly, we demonstrated that, although adolescent Mecp2-heterozygous (Mecp2-het) females showed a phenotype of reduced anxiety-like behaviour during basal conditions, maternal separation (MS) was able to further reduce anxiety-like behaviours in both Mecp2-het and their wild-type (WT) littermates in the elevated plus maze (EPM). Here, MECP2 is linked to Anxiety.