Super-Agers & Neurogenesis - Meta-Cognition - Organoid Questions - Dendrites

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Feb 28, 2026, 5:49:33 AMFeb 28

https://www.nytimes.com/2026/02/25/well/mind/super-agers-brain-neurons.html

Super-Agers’ Brains Have a Special Ability, New Study Suggests

By Dana G. Smith

Many people’s brains deteriorate as they age, becoming riddled with malfunctioning proteins that result in cell death and the loss of memory and cognition. But other people’s brains remain almost perfectly intact, their thinking as sharp at 80 as it was in their 50s.

A paper published Wednesday in the journal Nature provides a new potential explanation for this discrepancy, and it taps into one of the hottest debates in neuroscience: whether human brains can grow new neurons in adulthood, a phenomenon called neurogenesis.

The study found that so-called super-agers — people 80 and up who have the memory ability of someone 30 years younger — had roughly twice as many new neurons as older adults with normal memory for their age, and 2.5 times more than people with Alzheimer’s disease. The research focused on an area of the brain called the hippocampus, which is important for learning and memory and is thought to be the primary birthplace of new neurons.

“This paper shows biological proof that the aging brain is plastic,” even into a person’s 80s, said Tamar Gefen, an associate professor of psychiatry and behavioral sciences at the Northwestern University Feinberg School of Medicine, who contributed to the research.

To look for neurogenesis in older adults, the scientists first tried to detect signs of it in the autopsied brains of young adults, age 20 to 40, who died with normal cognition. They identified genetic markers for three key types of cells: neural stem cells, neuroblasts and immature neurons.

https://www.nature.com/articles/d41586-026-00599-5

Brains of ‘super agers’ are strong producers of new neurons

Mariana Lenharo

Adults whose brains still have strong neuron production seem to have better memory and cognitive function than do those in whom the ability wanes, finds a study published today in Nature1. The authors examined brain samples from deceased donors ranging from young adults to ‘super agers’ — people older than 80 with exceptional memory.

She lived to 117: what her genes and lifestyle tell us about longevity

They found that young and old adults with healthy cognition generated neurons, a process called neurogenesis, at high levels for their age. The team estimated that the new neurons made up only a small fraction — 0.01% — of those in the hippocampus, a brain region that’s essential for memory. By contrast, in people experiencing cognitive decline, including individuals with Alzheimer’s disease, neurogenesis seems to falter: the researchers spotted fewer developing, or immature, neurons in those brain samples.

Surprisingly, a group of ‘super agers’ had an even higher number of immature neurons than did other groups, and significantly more than did those with Alzheimer’s. However, the group sizes were small, so the findings were not all statistically significant.

Maura Boldrini Dupont, a neuroscientist and psychiatrist at Columbia University in New York City, says that the small size of the groups — each had ten or fewer individuals — is a reason to take the results with a grain of salt.

Understanding the tools that the brain uses to generate neurons and maintain cognitive function in old age could help researchers to develop drugs that induce neurogenesis in people with cognitive decline, says co-author Orly Lazarov, a neuroscientist at the University of Illinois Chicago.

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https://knowablemagazine.org/content/article/mind/2026/science-of-self-awareness-and-decision-making

Brain, think on thyself

By Tim Vernimmen

Steve Fleming’s research is definitely “meta” — a Greek prefix indicating self-reference. He’s a cognitive neuroscientist at University College London who studies metacognition: what we know about what we know, think about what we think, believe about what we believe. While this may seem quite philosophical and well-nigh impossible to study in the lab, he has made it his mission to measure and model it and understand where in the brain it manifests itself.

Fleming explored these issues in his 2021 book, Know Thyself: The Science of Self-Awareness. In the 2024 Annual Review of Psychology, he further examined the link between metacognition and confidence: our sense of whether we have made the right decision, whether we are successful at the tasks presented to us, and whether our worldview is likely correct.

Fleming’s work is casting new light on why some people seem chronically underconfident even when they’re doing just fine, and why others are entirely convinced they’re right about everything, even when there is overwhelming evidence to the contrary. In the following discussion, which has been edited for length and clarity, Fleming shared his thoughts on some of the questions that inevitably come up when our brains assess their own activity.

Metacognition is quite an uncommon research topic. How did you end up studying this?

I studied experimental psychology in Oxford, where I had the opportunity to work with psychologist Paul Azzopardi. He studies blindsight, a condition where, due to certain types of brain damage, people are subjectively blind but still able to perform various tasks using visual information. This presents a fascinating dissociation between conscious experience and actual functionality.

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https://undark.org/2026/02/26/brain-organoids-big-questions/

As Brain Organoid Science Grows More Complex, So Do the Questions

By Nora Belblidia

To the naked eye, Annie Kathuria’s experiments look a bit like tiny tufts of cotton floating in pink Petri dishes. These unassuming orbs are clusters of millions of human brain cells called brain organoids — brainstem organoids in this case — cultured in a lab in East Baltimore. Roughly a month old, the tufts are each around a millimeter wide, smaller than a coarse grain of salt.

“We have about maybe 500 to 600 organoids growing,” said Kathuria, an assistant professor of biomedical engineering and neurosurgery at Johns Hopkins University. In addition to the brainstem organoids, her lab is also growing other types that correspond to different parts of the nervous system: cortical organoids, which mimic a brain’s developing cortex, and spinal cord organoids, to model the spinal nerve tissue that connects to the brain.

Each of these clumps of neural tissue functions similarly to specific regions of the human brain. That similarity has led to some media coverage referring to them as “mini-brains” or “brains in a dish” — now irksome terms to many researchers in the field, some of whom also prefer the term neural organoids to brain organoids.
Annie Kathuria, assistant professor of biomedical engineering and neurosurgery, in her lab at Johns Hopkins University in Baltimore. Visual: Nora Belblidia for Undark

“Whatever else they are, they aren’t brains. They aren’t organized like brains. They aren’t big enough,” said Hank Greely, a Stanford University professor and expert in law and biosciences who works with researchers in the field. “But more importantly, they don’t have the right architecture.” By that he means organoids are basic parts of a whole, similar to how a broom closet or stairwell would never be considered a skyscraper.

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https://www.thetransmitter.org/dendrites/dendrites-help-neuroscientists-see-the-forest-for-the-trees/

Dendrites help neuroscientists see the forest for the trees

By Justin O’Hare

For decades, two complementary but often siloed approaches have guided neuroscience: cellular neuroscience, which seeks to understand how individual neurons work; and systems neuroscience, which aims to uncover how networks of neurons coordinate to produce thoughts, movements and behaviors. One studies the tree; the other studies the forest.

Each approach has produced tremendous advances. For instance, cellular neuroscientists have revealed how ion channels shape the electrical language of the brain, how synapses strengthen or weaken with experience and how gene expression governs neuronal function. Meanwhile, systems neuroscientists have mapped entire circuits, recorded the activity of tens of thousands of neurons during behavior and identified patterns of activity that correlate with memory, decision-making and emotion.

But for all these advances, a question lingers: Are we actually any closer to understanding how the brain works? The jaw-dropping datasets produced by systems-level studies are seldom reconciled with biology, and the exquisite detail uncovered by cellular-level studies is rarely extrapolated from circuits to behavior. These disconnects don’t reflect failures of either approach. Rather, they reflect the vast intellectual and material resources that each requires.

Nevertheless, the brain is a multiscale organ. It is organized across multiple hierarchical levels operating in concert, not in parallel. To unravel the brain’s deepest complexities, we need to bridge cellular and systems neuroscience. Because of recent technological advances in high-density electrical probes, genetically encoded fluorescent sensors, multiphoton imaging and high-performance computing, we are better suited to do this now than ever before.