GRM1 and fragile X syndrome: Since different areas of the brain correspond to different functions, defects of the mGluR1/5-dependent pathway in different areas of the FXS brain may not only lead to cognitive dysfunction, but also lead to epilepsy (prolonged epileptiform discharges in the hippocampus), anxiety (abnormal synaptic plasticity in the amygdala) and motor deficits deficit (cerebellum).