However, Karlsson et al. [32] observed no histopathological changes in the striatum, substantia nigra, dentate gyrus, cingulate cortex or retrosplenial granular cortex, and staining with Congo Red for identification of amyloid and immunohistochemical staining for phosphorylated tau, both pathological hallmarks of AD, was reported to be negative. Here, MAPT is linked to Alzheimer disease.