Neurogenesis: Neurogenesis is the growth and development of nervous tissue. Until recently, science believed people were born with all the neurons they’d have for a lifetime — growing them as children on “information highways,” called neural circuits, which create pathways across the brain. It was thought the addition of new neurons to the neural circuitry would change the flow of information and break the brain’s communication system. Research starting in the early 1960s eventually proved this wrong. Today, neuroscientists have solid evidence of neurogenesis in the adult brain and are researching the capacity of new adult neurons to proliferate or be replaced — and the implication for adult learning and memory.