The Brain Can Give Birth To New Cells Throughout Life, Study Finds
Researchers used to think that after adolescence, people were pretty well stuck with the brain cells they’d already formed. No so anymore. Discoveries in recent years have shown that neurogenesis—the formation of new neurons—can occur much later than this, well into adulthood. And now, a new study from the University of Illinois at Chicago finds that brain cells can form into one’s nineties, even if one has cognitive decline and Alzheimer’s disease (though at a much decelerated rate). The question is how the late-in-life growth of new neurons fits into what’s already known about degenerative diseases.
The study was published last week in the journal Cell Stem Cell.
The researchers looked at the postmortem brains of people aged 79-99, some of whom had had cognitive decline or Alzheimer’s disease. They targeted markers for two kinds of burgeoning cells—neuroblasts (stem cells that would one day give rise to neurons), and immature neurons—in the hippocampus, the brain area that's most affected in Alzheimer’s disease.
People who had died without cognitive problems had proliferation of both kinds of cells in their brains. People with cognitive decline and Alzheimer’s also had evidence of the cells, but in much lower numbers.
"We found that there was active neurogenesis in the hippocampus of older adults well into their 90s," said study author Orly Lazarov in a statement. "The interesting thing is that we also saw some new neurons in the brains of people with Alzheimer's disease and cognitive impairment."