Quantitative study of granule and Purkinje cells in the cerebellar cortex of the rat

Abstract

The numerical densities of granule and Purkinje cells in the cerebellar cortex of the rat were determined by stereological methods. The density of Purkinje cells in our fixed material was 1,018 ± 39 per mm² (mean ± s.e.m.) of Purkinje cell layer and that of granule cells 1.92 ± 0.03 × 10⁶ per μl of granular layer. The total area of Purkinje cell layer was 332 mm² and the volume of granular layer was 48 μl. The rat cerebellum therefore contains 3.38 × 10⁵ Purkinje cells and 9.2 × 10⁷ granule cells, from which there are 274 granule cells for each Purkinje cell. The density of granule cells and the density of parallel fibers in the molecular layer observed in a companion study indicate that the average length of a parallel fiber is around 5 mm.