Mossy fiber involvement in progressive supranuclear palsy

The cerebellar cortex of progressive supranuclear palsy (PSP) cases exhibit ed a characteristic pathology which occurred neither in healthy aged indivi duals nor in cases of fully developed Alzheimer's disease. All of the 11 PS P cases studied reveal altered mossy fiber excrescences containing abnormal and hyperphosphorylated tau protein. Moreover, this abnormal material also appeared in cerebellar oligodendrocytes. Accordingly, there is not only th e destruction of the cerebellar output system, which is already known, but also the involvement of the cerebellar input system.