Immunohistochemistry (IHC) of end‐stage SCA8 BAC mouse cerebellum shows that polySer but not polyGln is found in the molecular layer and cerebellar white matter and that polyGln but not polySer accumulates in Purkinje cells. Representative polySer aggregates are indicated by black arrows. Inset: higher magnification of molecular layer and white matter.
IF double staining shows no co‐localization of polyGln and polySer in frontal cortex, pons, or hippocampus of end‐stage SCA8 BAC mice.
IF double staining of end‐stage SCA8 BAC frontal cortex shows exclusive localization of polyGln (mouse α‐Gln, red, bottom panel) in neurons (rabbit α‐NeuN, green, bottom panel). In contrast, polySer (Rabbit α‐SerCT, red, top panel) shows widespread accumulation in the frontal cortex including within neurons (mouse α‐NeuN, green, top panel).
IHC of SCA8 human cerebellum shows that polySer accumulates in the white matter but not in the Purkinje cells (left panels), while polyGln accumulates in Purkinje cells but not cerebellar white matter (right panels).