Figure 2. Turnover dynamics of non-neuronal cells.

(A) Schematic illustration of the representation of the measured ¹⁴C concentration in genomic DNA. The black line indicates the ¹⁴C concentration in the atmosphere at different time points in the last century. Individually measured ¹⁴C concentrations in genomic DNA of human hippocampal cells are plotted at the time of the subject's birth (vertical lines), before (green dot) or after the ¹⁴C bomb spike (orange dot). ¹⁴C concentrations above the bomb curve (subjects born before the bomb peak) and data points below the bomb curve (subjects born after the nuclear tests) indicate cellular turnover. (B) The ¹⁴C concentrations of genomic DNA from non-neuronal cells demonstrate post-natal cell turnover in subjects born before and after the bomb spike. (C) Individual turnover rates for non-neuronal cells computed based on individual data fitting. Individual turnover rate calculations are sensitive to deviations in measured ¹⁴C and values <0.001 or >1.5 were excluded from the plot, but the full data is given in Table S1. (D) Non-neuronal average cell age estimates of cells within the renewing fraction are depicted (red curve). The dashed line represents a no-cell-turnover scenario.