Melatonin ameliorates sleep–wake disturbances and autism-like behaviors in the Ctnnd2 knock out mouse model of autism spectrum disorders

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder characterized by atypical patterns of social interaction and communication, as well as restrictive and repetitive behaviors. In addition, patients with ASD often presents with sleep disturbances. Delta (δ) catenin protein 2 (CTNND2) encodes δ-catenin protein, a neuron-specific catenin implicated in many complex neuropsychiatric diseases. Our previous study demonstrated that the deletion of Ctnnd2 in mice led to autism-like behaviors. However, to our knowledge, no study has investigated the effects of Ctnnd2 deletion on sleep in mice. In this study, we investigated whether the knockout (KO) of exon 2 of the Ctnnd2 gene could induce sleep–wake disorders in mice and identified the effects of oral melatonin (MT) supplementation on Ctnnd2 KO mice. Our results demonstrated that the Ctnnd2 KO mice exhibited ASD-like behaviors and sleep–wake disorders that were partially attenuated by MT supplementation. Overall, our current study is the first to identify that knockdown of Ctnnd2 gene could induce sleep–wake disorders in mice and suggests that treatment of sleep–wake disturbances by MT may benefit to autism-like behaviors causing by Ctnnd2 gene deletion.