Auditory Stimulation Rescues Cognitive Deficit in Fmr1-KO Mice

Abstract

Background/Objectives: Fragile X Syndrome (FXS) is a neurodevelopmental disorder caused by a triplet repeat expansion in the Fmr1 gene leading to the loss of Fragile X Messenger Ribonucleoprotein (Fmr1 protein). The loss of Fmr1 protein modulates many cell biological processes and leads to the emergence of intellectual disability and autism. FXS is modeled in Fmr1-KO mice that display features consistent with human FXS, including hypersensitivity, cognitive and learning deficits, hyperactivity and audiogenic seizures. Here, we investigated the effect of auditory stimulation during a range of developmental stages on recognition memory and sociability deficits in Fmr1-KO mice. Methods: Fmr1-KO mice were subjected to auditory stimulation for 2 min three times a day at one-hour intervals for 5 days at the nursing, juvenile and adult stages. The animals were tested for social interaction and novel object recognition at 2 to 3 months old. Results: During auditory stimulation, the wild running phenotype was observed in the Fmr1-KO juvenile animals and two animals at the nursing stage experienced status epilepticus and died. Fmr1-KO animals showed social deficits compared to both the control and animals exposed to auditory stimulation at the juvenile stage. In the novel object recognition task, auditory stimulation was more effective at the nursing and juvenile stages. Conclusions: These data show that auditory stimulation may be an effective way to restore cognitive and social deficits in FXS.