Cytophotometric identification of tetraploid Purkinje cells in young and aged rats.

DNA content of cerebellar basket and Purkinje cells of four month, one year, and two year old albino rats was determined by Feulgen cytophotometry. DNA content per nucleus remained essentially constant during aging although there was a slight shift to lower Feulgen-DNA values occurring in the one year age group. Purkinje cells of all three age groups were found to contain tetraploid amounts of DNA as compared to diploid basket cells.