Histochemical and ultrastructural investigation of heterogeneous Purkinje neurons in mammalian cerebellum.

The cerebellum of rat, rabbit, mouse, and bat were studied after staining with the Hematoxylin-Basic Fuchsin-Picric acid (HBFP) technique. In each species, heterogeneous Purkinje neurons became evident on the basis of red (i.e., fuchsinorrhagic) and blue (i.e., HBFP-negative) staining of cells. The former ranged from normal to atrophic-looking cells, while the blue staining Purkinje cells always showed typical perikaryal morphology with normal vesicular nucleus and prominent nucleolus. Staining differences were also seen by several different stains; however, the HBFP technique proved superior in the characterization of Purkinje cell heterogeneity owing to the tinctorial differences. The two classes of Purkinje neurons were still present after perfusion fixation. Electron microscopy demonstrated variable electron density in the Purkinje cells. Fuchsinorrhagic Purkinje neurons were absent in the 1-week old rats, but their number increased gradually thereafter. Tissue sections pretreated with RNase, DNase, or protease demonstrated that the fuchsinorrhagia of Purkinje neurons is a function of DNA/acidic protein complex. Since nucleic acids do not increase in Purkinje cells after maturation (i.e., after 8 weeks postnatal), the nucleic acids-associated-proteins, that are known to play a role in the regulation of gene expression, may be responsible for the fuchsinorrhagia of these Purkinje neurons.