The bulk of neurogenesis happens during the prenatal period of brain development, though new brain cells are made in certain areas of the brain throughout a person’s life.įollowing their creation, neurons must migrate to their designated areas of the brain, a process in which the structural and support cells called glia play an important role. During neurogenesis, stem cells become non-specialized neural progenitor cells, which in turn produce specific kinds of neurons. Neurogenesis is the process by which new neurons are created. The prefrontal cortex, involved in planning and other executive functions, is still developing into early adulthood (with changes such as synaptic pruning), later than a number of other brain areas. White matter volume continues to increase. Approaching maturity in early adulthood: Grey matter volume in the cortex continues to decrease in early adulthood, leveling out in a person’s 20s.Studies find that some structures beneath the cortex (such as the amygdala and hippocampus) increase in volume, while others (such as the striatum) are reduced. This process of selective pruning is affected by the environment and helps make adolescence a time of particular susceptibility to outside influence. The number of synapses between neurons in the cortex is scaled back. A transition period during adolescence: In teen brains, gray matter in the cortex thins considerably.Brain areas beneath the cortex (such as those in the limbic system) exhibit relatively little change. The areas of the cortex involved in movement and sensation reached maturity earlier than those involved in executive control, such as the prefrontal cortex, which will continue developing into adulthood. The density of synapses in the brain reaches its height and begins to decrease. Developmental peaks in childhood: The brain grows more gradually, with brain size peaking around age 10 for girls and age 14 for boys.Brain volume continues growing in the second year (an estimated 15 percent).
White matter pathways between spaced-apart regions of the cortex develop.
Major long-range signaling pathways made up of white matter begin to form several months into gestation and establish themselves by birth. The brain begins to develop its wrinkled outer surface. Rapid growth in the womb: By the last trimester of pregnancy, a fetus’s brain undergoes major increases in size, folding of the brain’s brain’s outer layer (cortex), and the development of connections between neurons.
But there are some major trends in the construction and remodeling that take place: The process of brain development through childhood and into adulthood is far from straightforward, with change happening at different rates in different parts of the brain.
0 kommentar(er)
