Differential staining patterns of immunohistochemical markers for neurogenesis staging in the premature cerebellum of ferrets and mice.

Immunohistochemical staining patterns of markers for neurogenesis staging were compared at the identical stage of cerebellar histogenesis between ferrets (aged 20 days) and mice (aged 10 days). Proliferating cell nuclear antigen (PCNA) immunostaining was observed largely in the granular precursors of the external granular layer (EGL) in both ferrets and mice. PCNA-immunostaining was also found in brain lipid-binding protein-immunopositive cells in the internal granular layer and was more abundant in ferrets than in mice. Paired box 6 immunostaining appeared largely in the EGL granular precursors in mice, whereas it emerged in the migrating/differentiating granular precursors in ferrets. These findings revealed that the types and neurogenesis stages of the EGL granular precursors detected by immunohistochemical markers differed between ferrets and mice.