Delayed touchscreen learning in Cdkl5 deletion mice. (A, B) Cdkl5^exon6−/+ females and Cdkl5^exon6−/y males took significantly longer to reach a criterion of completing at least 30 trials with 80% or higher accuracy on two consecutive days compared with wild-type, sex-matched littermates. (C, D) The percentage of mice that reached criterion was significantly higher in wild-type, sex-matched controls than Cdkl5^exon6−/+ females and Cdkl5^exon6−/y males. (E, F) Cdkl5^exon6−/+ females and Cdkl5^exon6−/y males completed fewer trials per session. (G, H) Cdkl5^exon6−/+ females and Cdkl5^exon6−/y males required higher correction trials to reach criterion. Data are expressed as mean ± S.E.M. ^*P < 0.05, ^**P < 0.001 and ^***P < 0.0001 indicate when the Cdkl5 mutant mice differ from wild-type, sex-matched littermate controls.