IRF1 and Alzheimer disease: Given that our data indicate that IRF-1 regulates the O-GlcNAcylation level of GluN1 and also influences the surface expression of GluN1 on the neuronal membrane, we investigate the dendritic spine density in hippocampal pyramidal neurons of 3xTg-AD mice injected with AAV-IRF-1 and IRF-1 knockout mice by Golgi staining.