Abstract

One hundred and thirty-nine complete human brains ranging in age from 10 weeks' gestation to 7 postnatal years, together with 9 adult brains, have been analysed in order to describe the human brain growth spurt quantitatively. The three major regions were examined for weight, DNA, cholesterol, and water content. The growth spurt period is much more postnatal than has formerly been supposed. The cerebellum has special growth characteristics; and there is a separate period from 10 to 18 weeks' gestation when adult neuronal cell number may largely be achieved. The implications of these findings for the vulnerability of developing brain are discussed.