VARIATIONS IN THE HUMAN PURKINJE CELL POPULATION ACCORDING TO AGE AND SEX

Abstract

Systematic measurements and Purkinje cell counts have been made on ninety ‘normal’ cerebella. Forty‐eight were male, forty‐two were female. Both hemispheres were sampled in thirty‐eight cases, giving a total of 128 hemispheres. The fresh volume of the cerebellum was measured in each specimen and corrections were made for changes in size during fixation and processing. The methods used and their rationale are described and discussed in detail. A mean of 6318 nucleolated Purkinje cells was counted in each of the 128 hemispheres. The mean length of the Purkinje cell line along which they lay was 1–5 m. Twenty‐seven binucleated Purkinje cells were seen out of the 811769 cells that were counted (about 1 per 30000); they appeared to be unrelated to age, sex or disease. The number of Purkinje cells per unit length of the Purkinje cell line and the number per unit area of the Purkinje cell sheet were found to be similar at all ages in the two sexes. Since, however, the male cerebellum tends to be larger than the female, the total number of Purkinje cells in the male is 6–8% higher than in the female. Wide individual variations were found in the same sex at all ages but a mean reduction of 2.5% per decade or of 25% over 100 years was identified. The figures suggested, however, that the reduction was curvilinear with the fall first becoming apparent at about the sixtieth year. No evidence was found that the drop was related to vascular degeneration or to any other identifiable pathological process.