Can New Neurons Teach an Old Mouse?

A decade ago, several independent brain studies found that adults continue to grow new neurons, overturning a long-held belief that the number of cells in a grown-up's brain can only move in one direction: down. Many scientists suggested that this continued "neurogenesis"—which mainly happens in a small region called the hippocampus—might explain how people continue to learn and adapt in new environments long after birth. But a new mouse study suggests that learning and memory may not depend on neurogenesis. The research raises questions about both the purpose of those mysterious new brain cells and the neurobiology behind adult learning.Read more at...Discover, June 2006.