MECP2 and Anxiety: To determine whether the decrease in anxiety like behaviour in Mecp2-null mice persist regardless of their decrease in motility, we also analysed the number of entries to the open arms after normalising by distance travelled (WT-naïve, 0.42 ± 0.04; Mecp2-null-naïve 0.85 ± 0.05; WT-MS 0.44 ± 0.06, Mecp2-null-MS 0.86 ± 0.03).