Four areas of the neural tube develop from the “front” (future head) to the “back” (future spine). These are called: the forebrain region, the midbrain region, the hindbrain region, and the spinal cord region. The forebrain region develops into the cerebrum and parts of the visual pathways outside the brain. The midbrain and hindbrain regions develop into the brainstem and cerebellum. The spinal cord region develops into the spinal cord.
Most cells of the central nervous system develop from neural stem cells, which are in an area called the germinal matrix. The germinal matrix is next to the cavity in the center of the neural tube, and these cells continue to multiply as the neural tube cavity becomes the ventricular system. Immature neural cells called neuroblasts migrate from the germinal matrix outward along specialized cells called radial glia to form most of the neurons and glia of the central nervous system. When immature neurons reach their intended position, they sprout an axon tipped with a structure called a growth cone. These developing axons grow until they reach their target cells, at which point they branch into axon terminals to form synapses. Most long-distance axonal connections form prior to birth.