Scientists Just Ended a 60-Year Debate About the Human Brain

For decades, scientists have argued over one of neuroscience’s most fundamental questions: Can the adult human brain grow new neurons? Now, researchers say they finally have the answer, and it changes everything.

A team led by Marta Paterlini at the Karolinska Institute in Sweden published their findingsin Science. The study confirms that neurogenesis, the process of forming new brain cells, does in fact occur in adult humans—even into old age.

Researchers from the Karolinska Institute in Sweden found clear evidence of neural precursor cells and immature neurons in brains ranging from children to adults as old as 78.

That discovery finally settles a controversy that’s lingered for more than 60 years.

In other animals, scientists have long known that the brain continues to make new neurons throughout life. But in humans, evidence was murky. Some previous studies identified young-looking brain cells in adults, but it wasn’t clear if they were truly new or just slowly maturing cells leftover from early development.

To find out, researchers used advanced RNA sequencing to detect the molecular signatures of newly formed neurons and their precursors. First, they tested brain samples from children. Then, they searched for those same genetic markers in 19 postmortem brains ranging from 13 to 78 years old.

They found what they were looking for—proof of active neurogenesis in most of the adult samples, including in regions of the hippocampus, the part of the brain involved in memory and learning.

The findings open new doors for brain research, especially when it comes to neurodegenerative diseases and mental health conditions.

Disrupted neurogenesis has been linked to Alzheimer’s disease and depression in mice, raising the possibility that therapies targeting this process could help prevent or treat these conditions in humans.Knowing these cells still exist in adulthood opens potential pathways for therapies that could stimulate brain regeneration.

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Scientists now believe other areas of the brain could also support neurogenesis, but that research is still ongoing.

This study doesn’t just lay to rest a stubborn scientific question. It lays a foundation for new research into brain plasticity, aging, and mental illness. As scientists now have proof of active neurogenesis in adult humans, the next steps will target how to harness and enhance this natural capacity.

For now, the long-standing debate has finally been resolved. Adult brains don’t just age—they adapt, and in some cases, they even grow.

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Scientists Just Ended a 60-Year Debate About the Human Brain first appeared on Men's Journal on Jul 10, 2025