FMR1 and Rett syndrome: Also, several animal models demonstrated that increased excitatory/inhibitory balance occurs in a large case of psychiatric pathologies resulting from genetic modifications, as indicated in (a) Oxt–/– or Scn1a+/– animals (the mouse models of myoclonic epilepsy associated with autistic behavior) (5, 58), (b) FMRP mice (genetic animal model of fragile X syndrome/mental retardation) (59), (c) REELER mouse model of schizophrenia (60, 61) (d) Mecpy/– mice for Rett syndrome (62, 63), and (e) the pharmacologically induced VPA model.