Neuronal Growth
and Organization
By 36 weeks gestation, the process of neuronal proliferation is nearly
complete. Although there is some limited proliferation of neurons throughout
life, their contribution to brain growth is negligible. Growth of the
individual neurons plus the elaboration and proliferation of dendritic
and axonal
processes and connections is responsible for most of the brain’s
growth.
The diameter of a neuroblast is 5 microns while a mature neuron
can measure 50 microns, a 1,000-fold increase in cell volume. Increase
in the size of glial cells also occurs. During the organization process
of brain development there is increasing dendritic arborization, synaptogenesis,
and axonal connections, which make a significant contribution to brain
growth as well as the maturation and development of brain function.
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