The development of the Bergmann fiber palisades in the cerebellum of the normal rat and in the weaver mouse.

The development of the Bergmann fiber palisades in the rat cerebellum was investigated by PAP immunocytochemistry using an anti-GFAP antibody. The Bergmann fibers are organized in parallel palisades as early as the second postnatal day and probably even earlier. This observation suggests that the organization and orientation of the palisades precedes the orientation of the parallel fibers in the same direction. Some Bergmann fiber palisades were also found in the adult homozygous weaver mouse, although it was more difficult to find palisades in these mutants than in the heterozygous or normal animals. The results are consistent with the hypothesis that during the early stages of cerebellar development the Bergmann fiber palisades organize the orientation of the parallel fibers in the longitudinal plane of the folium.