Summary: Some people in their 80s have memories as sharp as those in their 20s. A landmark study reveals their secret: adult neurogenesis. Researchers found that “superagers” have brains that are significantly more “neuronally fertile” than their peers.
While neurogenesis—the growth of new brain cells—typically slows with age, superagers produce new neurons in the hippocampus at twice the rate of healthy older adults. In contrast, individuals with Alzheimer’s disease showed almost no new neuron growth, suggesting that this “resilience signature” is a primary defense against cognitive decline.
Key Facts
- The Secret Ingredient: Superagers produce new neurons in the hippocampus—the brain’s memory center—at double the rate of standard healthy older adults.
- Adult Neurogenesis: The study confirms that humans continue to grow new neurons throughout their lives, including into their 80s and 90s.
- Three Stages of Growth: Researchers tracked “babies, toddlers, and teenagers” of the cell world—stem cells, neuroblasts, and immature neurons—to confirm active growth.
- Alzheimer’s Contrast: Brains with Alzheimer’s or early-stage dementia showed negligible to zero new neuron production, linking the loss of neurogenesis directly to cognitive failure.
- Epigenetic Blueprints: The new neurons in superagers have distinct epigenetic signatures, meaning their cells are better programmed to respond to environmental changes and stress.
Source: University of Illinois
Brains of older adults with super healthy cognition grow more new neurons than those of their peers, according to a study from UIC, Northwestern University and the University of Washington.
Researchers found that the brains of superagers — octogenarians with uncommonly nimble minds — were the most neuronally fertile, while those with Alzheimer’s disease had negligible new growth.
“This is a big step forward in understanding how the human brain processes cognition, forms memories and ages. Determining why some brains age more healthily than others can help researchers make therapeutics for healthy aging, cognitive resilience and the prevention of Alzheimer’s disease and related dementia,” said Orly Lazarov, a professor in UIC’s College of Medicine and director of the Alzheimer’s Disease and Related Dementia Training Program.
Neurons, or brain cells, support almost every human function. When you wiggle a toe or snap a finger, a neuron zaps a signal from your brain to your nervous system. In the latter half of the 20th century, researchers determined that new neurons could spawn throughout the lifespan in the brain’s hippocampus, or memory center — a phenomenon called adult neurogenesis.
At first, scientists observed neurogenesis in rodents and were skeptical about whether it would appear in other mammals. Then, studies in primates linked neurogenesis to healthier aging brains, particularly stronger memory formation and processing.
This recent study, published in Nature, affirms that neurogenesis occurs in adult humans as well.
The researchers looked at donated brain samples from five groups: healthy young adults; healthy older adults; older adults with exceptional memory, or superagers; individuals with mild or early dementia; and those diagnosed with Alzheimer’s disease.
The superager brains in the samples came from donors aged 80 years or older with exceptional memory skills. Brain samples from superagers were obtained from Northwestern University. The University of Washington supplied all other samples.
The researchers searched for three stages of developing neurons in the brains’ hippocampi: stem cells, which could potentially evolve into neurons; neuroblasts, adolescent stem cells on their way to neuronhood; and immature neurons, which are just shy of becoming functional.
“Think of the stages of adult neurogenesis like a baby, a toddler and a teenager,” Lazarov said. “All are signs that these hippocampi are growing new neurons.”
Results indicated that hippocampal neurogenesis, or the formation of new neurons in the hippocampus, does indeed occur in healthy human adults. Further, superagers actively produced more new neurons than their counterparts — their distinct “resilience signature.”
“Superagers had twice the neurogenesis of the other healthy older adults,” Lazarov said. “Something in their brains enables them to maintain a superior memory. I believe hippocampal neurogenesis is the secret ingredient, and the data support that.”
Brain samples from individuals with preclinical cognitive decline — the earliest stage of cognitive decline, before symptoms start to appear — displayed minimal neurogenesis. Those diagnosed with Alzheimer’s disease generated almost no new neurons.
Further, the researchers observed that the new neurons had different epigenetic signatures — or blueprints for responding to environmental change — depending on the brains’ cognitive health.
“Modern medicine has revolutionized health care such that life expectancy is greater now than ever before,” said co-lead author Dr. Jalees Rehman, the Benjamin J. Goldberg Professor and head of the department of biochemistry and molecular genetics at UIC.
“We need to ensure that this overall increased life expectancy goes along with a high quality of life, including cognitive health.”
Rehman said that understanding the full molecular picture of neurogenesis and its epigenetic signature can inform targeted therapeutics to preserve memory and cognitive function in aging adults. Next, this team will examine environmental and lifestyle factors — like diet, exercise and inflammation — that may work alongside neurogenesis to impact aging.
“What’s exciting for the public is that this study shows the aging brain is not fixed or doomed to decline,” said Ahmed Disouky, the first author of the study. “Understanding how some people naturally maintain neurogenesis opens the door to strategies that could help more adults preserve memory and cognitive health as they age.”
Additional UIC coauthors include Mark Sanborn, K. R. Sabitha, Mark Maienschein-Cline and Mostafa Mostafa from the College of Medicine.
Brain and tissue samples were obtained from the University of Washington Alzheimer’s Disease Research Center, the Adult Changes in Thought study, the Pacific Northwest Brain Donor Network, the Allen Institute for Brain Science, the Northwestern University Alzheimer’s Disease Research Center, the SuperAging Research Initiative, the Karen Toffler Charitable Trust and the Gefen-Querrey Brain Health Fund.
Funding: The study was supported by the National Institute on Aging awards AG033570, AG033570-S2, AG076940, AGO79002, AG060238, AG061628 and AG091545.
Key Questions Answered:
A: A superager is someone aged 80 or older whose memory is as nimble as that of a healthy person 20 to 30 years younger. This study shows they aren’t just “lucky”—their brains are physically working harder to stay young by growing new cells.
A: While genetics play a role, the researchers found that these new neurons have “epigenetic signatures,” which are blueprints for how cells respond to the environment. This suggests that lifestyle factors like diet and exercise could potentially help stimulate this growth.
A: No! This study is exciting because it proves the aging brain is not “doomed” to decline. If we can figure out how to jumpstart neurogenesis in everyone, we could potentially prevent Alzheimer’s and other forms of dementia.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this neurogenesis and aging research news
Author: Francesca Sacco
Source: University of Illinois
Contact: Francesca Sacco – University of Illinois
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Human hippocampal neurogenesis in adulthood, ageing and Alzheimer’s disease” by Ahmed Disouky, Mark A. Sanborn, K. R. Sabitha, Mostafa M. Mostafa, Ivan Alejandro Ayala, David A. Bennett, Yisha Lu, Yi Zhou, C. Dirk Keene, Sandra Weintraub, Tamar Gefen, M.-Marsel Mesulam, Changiz Geula, Mark Maienschein-Cline, Jalees Rehman & Orly Lazarov. Nature
DOI:10.1038/s441586-026-10169-4
Abstract
Human hippocampal neurogenesis in adulthood, ageing and Alzheimer’s disease
The existence of human hippocampal neurogenesis has long been disputed and its relevance in cognition remains unknown. Recent studies have established the presence of proliferating progenitors and immature neurons and a reduction in the latter in Alzheimer’s disease (AD). However, their origin and the molecular networks that regulate neurogenesis and function are poorly understood.
Here we studied human post-mortem hippocampi obtained from different cohorts: young adults with intact memory, aged adults with no cognitive impairments, aged adults with extraordinary memory capacity (SuperAgers), adults with preclinical intermediate pathology or adults with AD.
Using multiomic single-cell sequencing (single-nucleus RNA sequencing and single-nuclei assay for transposase-accessible chromatin with sequencing), we analysed the profiles of 355,997 nuclei isolated from the hippocampus samples and identified neural stem cells, neuroblasts and immature granule neurons.
Dysregulated neurogenesis was largely associated with changes in chromatin accessibility. Analyses of transcription factors and target gene signatures that distinguished each of the groups revealed early alterations in chromatin accessibility of neurogenic cells from individuals with preclinical AD, and such changes were even more evident in samples from individuals with AD.
We identified a distinct profile of neurogenesis in SuperAgers that may reflect a ‘resilience signature’. Finally, alterations in the profile of astrocytes and CA1 neurons govern cognitive function in the ageing hippocampus.
Together, our study points to a multiomic molecular signature of the hippocampus that distinguishes cognitive resilience and deterioration with ageing.
