MAPT and Alzheimer disease: While staining in the white matter region revealed sparse tau immunoreactive glial inclusions and processes, in AD brain tissue these antibodies revealed much more intense staining of the gray matter neuropil regions relative to the white matter regions in the frontal cortex (Fig. 2), temporal cortex (Fig. 3), parietal cortex (Additional file 1: Fig. S2), and occipital cortex (Additional file 1: Fig. S3).