Cresyl violet staining reveals that the cerebellar cortex of Apoer2 and Vldlr mutants is abnormal.

Sagittal sections through the medial cerebellum of adult wild type (A, D), Apoer2 (B, E) or Vldlr (C, F) null animals indicate that mutant cerebella are smaller and have fewer lobules when compared to wild type mice. Higher-power views reveal that a trilaminar structure is present in both mutants and wild type (D–F) consisting of an outer molecular layer (ML), Purkinje cell layer (PCL) and inner granule cell layer (GL). White matter tracts (WM) can also be observed in each animal. High magnification views of the Vldlr null cerebellum reveal the presence of Purkinje cell-sized somata in the granular layer and white matter (e.g. black arrowheads–F) as well as gaps in the Purkinje cell layer (white arrowheads–F). Measurements of the length of lobules in Apoer2 null (G) or Vldlr null (H) cerebella are expressed as a percentage of the length in wild-type littermates. Length measurements reveal a reduction in several areas of each mutant cerebellum. These reductions are most prominent in the anterior cerebellum of both mutants. Error bars on the graph depict SEM. Dotted line indicates the length of the equivalent lobule in wild type animals. Scale bar = 1 mm for A–C and 125 µm for D–F. * indicates p<0.05 as determined by one way ANOVA.