Early Neural Development

The brain is the most complex organ in the body with the fastest embryonic development. Three main parts of the brain can be identified when the baby is inside the mother: the cerebrum, the midbrain, and the brainstem. Memory, learning, and decision-making happen in the cerebrum. The midbrain and the brainstem control tasks such as heart rate, renal, and gastric functions. These two regions are the most active while the fetus develops, because involuntary functions are of primary importance at that stage. At the same time, the cerebrum develops anatomically, but is less active because there is limited external stimuli. When the baby is ready to be born, the brain already has 100 billion mature cells called neurons. Those are the only neurons that the brain will ever have for the duration of the baby’s life. The neurons in the midbrain and brainstem have already formed many connections called synapses. However, as the cerebrum was largely inactive during gestation, the synapses that form the physical basis of memory, learning, and brain growth are lacking, but not for long. At birth, exposure to the world activates the cerebrum. New external stimuli, like sounds, sensations of touch, sights, scents, and tastes individually and collectively contribute to the 700 neural connections made every second. Basic connections allow the newborn to react to this stimuli with various reflexes. After 36 months, these reflexes become refined as connections are pruned so the child has more control over tasks. These refinements happen after almost 80% of the child’s brain development has already occurred.