Scientists have discovered the steps required to integrate neurons into existing brain operations, according to Science Blog. Not only can the brain add neurons but -- at least in mice -- the added cells can function as part of the brain. The discovery is significant for its disease fighting implications. From the article:
Among the most likely targets for regeneration or replacement efforts are thedopamine-producing neurons that die in Parkinson's disease, muscle-controlling nerves that succumb in diseases like muscular dystrophy and amyotrophic lateral sclerosis, or nerves that are damaged by trauma or injury. In none of these systems are new neurons formed or integrated to any great extent naturally.