MAPT and Alzheimer disease: The present observations show tau seeding and spreading in the corpus callosum of WT mice following inoculation of homogenates from AD (4R+3R tauopathy + β-amyloidopathy), and pure neuronal 4R+3R tauopathy (PART), pure astrocyte 4R tauopathy (ARTAG), combined neuronal and glial 4R tauopathy (PSP), neuronal and glial 4R tauopathy with specific globular glial inclusions (GGT), 3R tauopathy (PiD), and familial FTLD-P301L.