Rubber tail illusion is not obvious in SH3 and multiple ankyrin repeat domains 3 (Shank3)-knockout mice.

Atypical body representations are often observed in individuals with autism spectrum disorder (ASD). The rubber tail task, which involved stroking both a real tail and a rubber tail, was designed to investigate the body ownership illusion in mice. A previous study showed that the body ownership illusion (i.e. the rubber tail illusion) is not obvious in Ca2+-dependent activator protein for secretion 2 (Caps2)-knockout (KO) mice, which exhibit ASD-like phenotypes. If this phenotype is a widespread feature of ASD models, then the rubber tail illusion should be attenuated in other strains of ASD model mice. Therefore, we investigated the rubber tail illusion in SH3 and multiple ankyrin repeat domain 3 (Shank3) KO mice, a common ASD mouse model. After synchronous stroking of the real and rubber tails, a significantly stronger response was observed in wild-type (WT) mice when the rubber tails were grasped. In contrast, no significant difference in the response rate was observed between synchronous and asynchronous stroking in Shank3-KO mice, although the response rate was much lower than that in WT mice. These results suggested that the rubber tail illusion was not obvious in Shank3-KO mice, although the influence of hyporeactivity cannot be completely ruled out.