Compensatory refers to the ability of some cells to replace the function of others, and the restoration of function can be obtained after nerve cell injury or destruction. It has been demonstrated that only in the early stages of growth and development can localized cellular deficits be compensated for by neighboring cells, but after a certain sensitive period, the defects become permanent. If the brain is 1injured early in development, function is rarely affected by adulthood. The authors have seen two children around 3 years of age who, on gross appearance, had similar intellectual and motor abilities to normal children of the same age, but a large defective hyaline area was seen on one side of the brain on a cranial CT film. On tracing the history, it was a brain injury caused by an intracranial hemorrhage at more than 2 months after birth. If this had occurred in an adult, it would certainly have caused significant paralysis of one side of the body and other brain function problems. The specific learning disabilities caused by injury to the adult brain often cannot be compensated for or completely, whereas infant brain injury often produces learning disabilities in younger girls because of the restorative function of the infant brain. Surgical removal of one of the eyes of an animal’s fetus early in gestation is followed by a significant increase in the number of optic nerve dendrites in the surviving eye. In infancy, especially in early childhood, damage to the central nervous system can still result in the formation of functional pathways, where axonal bypasses of nerve cells are connected to the dendrites of other nerve cells. Some nerve cells develop specialized bifurcations or produce a large number of specialized nerve cell-to-nerve cell associations, called synapses, for compensatory functions.