Retrospective birth dating of cells in humans

Methodological flaws have been proposed as explanations for putative false positive and false negative data on this subject (13,26).

The development and application of new methods is clearly needed to resolve the debate about adult neurogenesis in neocortex and other “non-neurogenic” brain regions.

We use this strategy to determine the age of cells in the cortex of the adult human brain, and show that whereas non-neuronal cells are exchanged, occipital neurons are as old as the individual, supporting the view that postnatal neurogenesis does not take place in this region.Using this approach, the average age of cells in two regions of the adult human brain autopsy tissue—the cerebellum and occipital cortex—were estimated.The authors found that cells in the occipital cortex were younger than cells in the cerebellum, but when neurons and non-neurons were separated, the occipital cortex neurons were the oldest, almost as old as the individual.Retrospective birth dating is a generally applicable strategy that can be used to measure cell turnover in man under physiological and pathological conditions.About 40 years ago, Joseph Altman and his colleagues used the 3H-thymidine autoradiographic method to birthdate cells in the brains of adult rats and cats, and reported evidence for neurogenesis in the olfactory bulb, hippocampus, and neocortex (1-5).

Leave a Reply