Non-cell-autonomous pathology involving glial cells has been implicated in Purkinje cell degeneration. We reported previously that mutant
ataxin-1, a causative gene product of
spinocerebellar ataxia type 1 (
SCA1), prevents Bergmann glia proliferation in mutant
ataxin-1 knockin mice and that suppressed Bergmann glia function leads to Purkinje cell degeneration. However, because reactive astrocytes are produced in response to
brain injuries and diseases, Bergmann glia are also suspected to proliferate and increase in response to Purkinje cell degeneration, including during
SCA1 pathogenesis. However, little is known about reactive Bergmann glia (Bergmann
gliosis) and its beneficial or detrimental role. Given the lack of quantitative studies of Bergmann glia using specific molecular markers, we quantified Bergmann glia in human
SCA1 brains with Bergmann glia-specific Sox2 staining and conventional
hematoxylin and
eosin staining. Our results showed reduced numbers of Bergmann glia in
SCA1 patient brains and support the hypothesis that Bergmann glia loss contributes toward Purkinje cell degeneration in human
SCA1.