Figure 7.

Rate of DNA alteration in developing brain and distribution of genomic mosaicism in mature neurons. (A) In embryonic brain development, DNA alteration rates peak during periods corresponding with high levels of neurogenesis, before leveling off. (B) After prenatal development, genomic alterations continue to accumulate during neonatal and childhood neurodevelopmental periods, with smaller alterations accruing thereafter. (C) Taken together, genomic mosaicism accumulates over a lifetime, starting during embryonic brain development, and continuing throughout life and into adulthood and old age, potentially contributing to age related neurological disorders. Importantly, the vast majority of these somatic changes can only be detected when the mosaic nature of individual neurons is considered in experimental design. [Color figure can be viewed at http://wileyonlinelibrary.com]