Abnormal CFs in MSA cases. The cerebellar cortical sections labeled with anti-VGlut2 antibody of MSA cases demonstrated abnormal CFs oriented parallel to the PC layer (a). Thickened CFs extended from the granule cell layer (arrows) to the proximal part of PC dendrites (arrowheads) before transitioning into normal appearing CFs (b). Dual immunofluorescence with anti-calbindinD28k antibody (Alexa 594, red) (c, f, i) and anti-VGlut2 (Alexa 488, green) (d, g, j) of cerebellar sections of MSA cases show that abnormal CFs (d, e, arrows) run perpendicular to fragmented PC dendrites (c, e, arrowheads). In addition, some abnormal CFs (g, h, j, k) form synapses with the very proximal part of the dystrophic PC dendrites (f, h) or fragmented PC dendritic dendrites (i, k) in the cerebellar cortex. The abnormal CF synapses (arrows, m, n) that are parallel to PC layers partially colocalize with neurofilament, supporting that these fibers are CF axons (arrows, l, n). ML molecular layer. PCL Purkinje cell layer