Aging and the nerve cell population of the putamen: a morphometric study.

Whereas the numbers of nerve cells in several areas of the cerebral cortex are reported to decrease with aging, the fate of the neurons of the subcortical nuclei is controversial. This work is concerned with a morphometric study of the nerve cell population of the putamen through cell counting in 24 subjects aged 62 to 90 years. Our data suggest that there is no significant decline in the small-cell density with aging, nor any differences according to sex. No conclusions on the functions of the aging brain should be inferred from cell counting alone, since other signs of functional damage, such as impairment of the synapses or decrease in their number probably precede cell loss.