Neurogenesis

This entry describes the occurrence and significance of neuron birth, or neurogenesis, as a feature of brain development that persists over the life span. During early brain development, approximately 3 weeks after conception, the neural tube closes to form the central canal that will constitute the brain’s ventricular system. Lining the inside of this canal is a layer of specialized cells that will divide throughout development, ultimately giving rise to the approximately 80 billion neurons of the adult brain. These special cells continue to be the source of new neurons as the neurons themselves are not capable of dividing. It is this particular feature that was noted by Santiago Ramón y Cajal at the turn of the 20th century in his paradigm-shifting descriptions of neuronal ...