New nerve cells

The battle over new nerve cells in adult brains intensifies

New methods are needed to settle the debate

BY 

LAURA SANDERS 

7:00AM, DECEMBER 20, 2018

NO SIGNS  In a study of human brains, young nerve cells (green) were visible in the memory-related hippocampus of a newborn (left), but were rare in a sample from a 13-year-old (center). None were seen in adult brains, including this sample from a 35-year-old (right).

Just a generation ago, common wisdom held that once a person reaches adulthood, the brain stops producing new nerve cells. Scientists countered that depressing prospect 20 years ago with signs that a grown-up brain can in fact replenish itself. The implications were huge: Maybe that process would offer a way to fight disorders such as depression and Alzheimer’s disease.

This year, though, several pieces of contradictory evidence surfaced and a heated debate once again flared up. Today, we still don’t know whether the fully grown brain churns out new nerve cells./.../