Susceptibility of the Developing Nervous System:
The brain is especially susceptible to numerous environmental
insults that can produce irreversible damage during critical periods
of nervous system development between conception and the age
of 21. This vulnerability is well recognized for ionizing radiation,
alcohol, tobacco, some pharmaceuticals, cocaine, and stress.
The effects of these agents are dependent on dose and timing
of exposure. However, even small exposures during periods of
neurogenesis have a more profound effect than exposures during
adulthood.