Retrospective birth dating of cells in humans

Cell. 2005 Jul 15;122(1):133-43. doi: 10.1016/j.cell.2005.04.028.


The generation of cells in the human body has been difficult to study, and our understanding of cell turnover is limited. Testing of nuclear weapons resulted in a dramatic global increase in the levels of the isotope 14C in the atmosphere, followed by an exponential decrease after 1963. We show that the level of 14C in genomic DNA closely parallels atmospheric levels and can be used to establish the time point when the DNA was synthesized and cells were born. We use this strategy to determine the age of cells in the cortex of the adult human brain and show that whereas nonneuronal cells are exchanged, occipital neurons are as old as the individual, supporting the view that postnatal neurogenesis does not take place in this region. Retrospective birth dating is a generally applicable strategy that can be used to measure cell turnover in man under physiological and pathological conditions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aging / physiology*
  • Air Pollutants, Radioactive / analysis
  • Air Pollutants, Radioactive / metabolism
  • Carbon Radioisotopes / analysis
  • Carbon Radioisotopes / pharmacokinetics
  • Cell Nucleus / chemistry
  • Cell Nucleus / metabolism
  • Cellular Senescence / physiology*
  • Cerebral Cortex / cytology
  • Cerebral Cortex / growth & development
  • Cerebral Cortex / physiology
  • DNA / biosynthesis
  • DNA / chemistry
  • Humans
  • Male
  • Neurons / chemistry
  • Neurons / cytology*
  • Neurons / physiology*
  • Nuclear Warfare / statistics & numerical data
  • Organ Specificity
  • Pinus / chemistry
  • Retrospective Studies
  • Time


  • Air Pollutants, Radioactive
  • Carbon Radioisotopes
  • DNA