New Evidence of Neurogenesis in Adult Human Brains

In a groundbreaking study published on July 3, 2025, in the journal Science, researchers have unveiled compelling evidence that the adult human brain is capable of forming new neurons, a process known as neurogenesis. This discovery could put to rest a long-standing debate about the brain’s ability to regenerate itself and has significant implications for our understanding of learning, memory, and emotional health.

The research, led by Marta Paterlini from the Karolinska Institute in Stockholm, demonstrates that neurogenesis occurs primarily in the hippocampus, a critical region of the brain associated with learning and memory. “In short, our work puts to rest the long-standing debate about whether adult human brains can grow new neurons,” Paterlini stated.

While previous studies have confirmed neurogenesis in animals like mice and rats, obtaining high-quality brain tissue samples from adult humans has historically posed significant challenges. The study’s authors employed advanced techniques such as single-nucleus RNA sequencing and machine learning to analyze brain tissue samples from various international biobanks. These innovative methods allowed them to examine over 400,000 individual nuclei from the hippocampus of 24 individuals, ranging from infants to 78-year-olds.

The researchers found that groups of dividing precursor cells were located adjacent to fully formed neurons, mirroring findings from animal studies. Notably, these precursor cells were present not only in children but also in teenagers and adults, suggesting that the potential for neurogenesis persists throughout life.

By utilizing fluorescent tags to mark proliferating cells, the scientists were able to develop a machine learning algorithm that identified cells likely to become neurogenic stem cells. This approach was praised by experts, including Dr. Rajiv Ratan, CEO of the Burke Neurological Institute, who emphasized the significance of the study in advancing clinical neuroscience.

Interestingly, while the brains of children produced more new neurons than those of adolescents or adults, the study revealed that nine out of 14 adult brains showed signs of neurogenesis with one technique, and all ten adult brains analyzed with a second technique displayed new cells. The researchers caution that further investigation is needed to understand the factors influencing neurogenesis in adults, particularly in relation to neurological diseases such as Alzheimer’s.

Looking ahead, the findings open new avenues for research into the relationship between neurogenesis and cognitive health. Dr. W. Taylor Kimberly from Massachusetts General Brigham noted the potential for comparing patients with dementia to “super agers” who exhibit cognitive resilience in old age. Understanding how neurogenesis relates to disease could pave the way for innovative treatments.

The implications of this research extend beyond the realm of neuroscience. The notion that adult brains can generate new neurons challenges traditional views on lifelong learning and recovery from brain injuries. As Paterlini highlighted, “the very fact that our adult brains can sprout new neurons transforms how we think about lifelong learning, recovery from injury, and the untapped potential of neural plasticity.”

As scientists continue to unravel the complexities of the human brain, this study marks a significant milestone in our understanding of neurogenesis and its potential impact on our lives. The journey of discovery is far from over, and the future may hold exciting possibilities for enhancing brain health and cognitive function throughout adulthood.