Fig. 4

THIP administration alleviated the defects of social behaviors in MECP2-null mice. During the habituation period in the three chamber test, both WT and null mice took similar amount of times (a) and transitions (b) in either side of the chambers indicating no preference. The main effect preference was not significant. (a F = 1.72, df = 1, P = 0.195; b F = 0.20, df = 1, P = 0.656; three-way ANOVA). The transitions between the chambers also suggested that the tested animals are not in a sedative state. c In the sociability test, a significant difference was detected within the main factor of preference (F = 23.31, df = 1, ^### P < 0.001, three-way ANOVA). WT mice spent significantly more time in the chamber containing an animal than the empty one, whereas the MECP2-null mice lost such a preference. THIP administration increased the time expenditure of MECP2-null mice in interacting with another mouse (*P < 0.05; Tukey’s post hoc). No significant differences were found in the main factor of genotype (F = 1.20, df = 1, P = 0.278) or THIP treatment (F = 0.03, df = 1, P = 0.863). The interactions of genotype × treatment (F = 0.46, df = 1, P = 0.500), genotype × preference (F = 1.41, df = 1, P = 0.239), treatment × preference (F = 3.31, df = 1, P = 0.074), or genotype × THIP treatment × preference (F = 2.08, df = 1, P = 0.155) were not significant as well (three-way ANOVA). d In the social novelty test, the main factor of preference showed a significant difference (F = 54.48, df = 1, ^### P < 0.001, three-way ANOVA). WT mice spent significantly more time in the chamber with a novel animal than the chamber with a familiar one, whereas the MECP2-null mice did not show the preference to either chamber. With THIP treatment the novelty preference was improved in the MECP2-null mice (**P < 0.01, ***P < 0.001; Tukey’s post hoc). No significant differences were found in the main factor of genotype (F = 0.57, df = 1, P = 0.453) or THIP treatment (F = 0.17, df = 1, P = 0.681). The interactions of genotype × treatment (F = 0.02, df = 1, P = 0.888), genotype × preference (F = 0.49, df = 1, P = 0.487), treatment × preference (F = 1.58, df = 1, P = 0.213), or genotype × THIP treatment × preference (F = 1.35, df = 1, P = 0.250) were not significant as well (vehicle: n = 12 and n = 9; THIP: n = 8 and n = 6; WT and MECP2-null, respectively; three-way ANOVA)