brain development baby

The beginning of brain development starts soon after conception and continues throughout the prenatal period. The main thing that’s happening is the production of brain cells, called "neurons." During this time, the brain produces many more neurons than it needs, and by birth, excess cells have been shed. At birth, a baby’s brain has approximately 100 billion neurons--just about enough to last a lifetime. During the pre-natal period, neurons must find their way to exactly the right position on the cortex wall (where thinking and remembering occur); if they go astray, this can cause serious developmental problems (tobacco, alcohol and substance use, as well as radiation, are the most common causes of such problems).