Alzheimer's tau protein has a surprising secret role in memory

New research has revealed that tau, a protein best known for its connection to Alzheimer's disease, is also essential for creating long lasting memories. The discovery provides new insight into how healthy memory works and could help guide future efforts to develop treatments for dementia.

The study, led by Flinders University in partnership with researchers from the University of New South Wales and Macquarie University, was published in Nature Communications. It found that tau helps organize and stabilize memories so they can be retained over time.

The researchers studied "remote memory" in mice, which refers to memories recalled days or weeks after an experience. They discovered that tau is not necessary for learning something new or remembering it shortly afterward. Instead, it plays a crucial role in making those memories durable over the long term.

Because the research was conducted in mice, the findings cannot be directly applied to human memory or Alzheimer's disease. Even so, the results offer valuable clues that could shape future dementia research and treatment strategies.

Tau's Role in Long Lasting Memory

Senior author Associate Professor Arne Ittner, a neuroscientist from Flinders' College of Medicine and Public Health, says the findings help explain why people with dementia may still be able to learn new information initially, yet struggle to retain it.

"Why some memories last while others fade has long puzzled scientists and our study shows that tau plays a key role in how the brain forms long-lasting memories. Without it, memories can still form in the moment, but they are weaker," says Associate Professor Ittner.

The team focused on specialized brain cells called "engram cells," which create the physical record of a memory. When a new experience occurs, only a small number of these cells are selected to store it.

According to the study, tau is active during this critical stage of memory formation, helping determine exactly which engram cells are recruited to preserve the experience.

One of the study's lead authors, Renée Kosonen, says tau acts like an organizer that helps the brain build accurate and lasting memories.

"Our findings show that tau helps determine which cells are selected to store a memory, shaping how an experience forms a lasting memory trace," says Ms Kosonen, a researcher at Flinders' Neuroscience and Dementia Research.

How Tau Organizes Memory

The researchers also found that tau reduces unnecessary or "noise" activity in the brain during memory formation. By limiting this background activity, tau allows only a specific group of cells to become part of a memory, producing clearer and more stable memory traces.

The team identified an important molecular process behind this effect. As learning takes place, tau undergoes a subtle chemical change called phosphorylation, which helps coordinate the activity of engram cells.

Although abnormal tau phosphorylation is a well known feature of Alzheimer's disease, the study shows that controlled, low level phosphorylation is a normal and essential part of healthy brain function.

New Clues About Alzheimer's Disease

The researchers made another surprising discovery. Even in the absence of tau, memory traces still existed and could be recovered by directly stimulating engram cells. This suggests that tau is not required to store memories themselves. Instead, it appears to be needed to connect natural cues, such as sights and sounds, with the ability to recall those memories.

The findings also provide new insight into how Alzheimer's related tau may interfere with memory. When disease associated forms of tau were present in engram cells during learning, they disrupted the creation of new memories. When those abnormal forms appeared after memories had already formed, they interfered with the brain's ability to retrieve them.

These effects were associated with abnormal patterns of brain activity, suggesting that memory problems in dementia may result not only from memories being lost, but also from disruptions in how memories are organized and accessed.

"Knowing how tau supports the formation and recall of memory could help us better understand what goes wrong in memory loss," says Associate Professor Ittner.

"Future research will hopefully be able to confirm concepts developed in our study in human memory and show their implication in dementia."

The researchers conclude that tau should be viewed not only as a protein involved in Alzheimer's disease, but also as a fundamental regulator of how the brain organizes, stores, and retrieves lasting memories. That new perspective could deepen scientists' understanding of both healthy memory and the biological changes that contribute to Alzheimer's disease.

Journal Reference:

1. Renée Kosonen, Kristie Stefanoska, Yijun Lin, Samantha Edwards, Emmanuel Prikas, Josefine Bertz, Anne Poljak, Lars M. Ittner, Arne Ittner. Tau T205 phosphorylation modulates engram cell recruitment and remote memory in mice. Nature Communications, 2026; DOI: 10.1038/s41467-026-73207-9

Courtesy:

Flinders University. "Alzheimer's tau protein has a surprising secret role in memory." ScienceDaily. ScienceDaily, 12 July 2026. <www.sciencedaily.com/releases/2026/07/260710003535.htm>.  

 

 

 

Scientists may have finally found how Alzheimer's kills brain cells

Scientists have identified evidence of a previously unknown process that may explain how brain cells die in Alzheimer's disease and frontotemporal dementia (FTD). The discovery, centered on a mechanism known as karyoptosis, could point researchers toward new ways to slow the progression of these devastating conditions.

Many neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), Alzheimer's disease, and FTD, are marked by the buildup of harmful proteins inside neurons. Over time, these nerve cells die, contributing to memory loss and other symptoms. Although scientists have long known about several forms of cell death, including apoptosis, those mechanisms have never fully explained the extensive neuron loss seen in these disorders.

Now, researchers from King's College London, working with the UK Dementia Research Institute and supported in part by Alzheimer's Research UK, have identified karyoptosis as a potential missing link connecting toxic protein accumulation to the death of brain cells.

Karyoptosis refers to a series of chemical reactions set in motion when toxic proteins accumulate inside a cell. As the process unfolds, the cell's nucleus, which contains its genetic material, gradually shrivels before ultimately breaking apart.

Evidence Found in Alzheimer's and FTD Brains

The findings, published in Nature Communications, are based on an analysis of 3,000 brain cells collected from 28 people with either FTD or end stage Alzheimer's disease. Using computational algorithms, the researchers identified different forms of cell death occurring within the tissue.

They found signs of karyoptosis in 35 percent of cells from the frontal cortex of people with Alzheimer's disease, compared with just 15 percent of cells from healthy older adults.

"This study is the culmination of a 10-year journey at King's, from when we first identified karyoptosis in a relatively rare disease to discovering that it is a common feature of dementias which affect millions of people."

A Possible New Target for Dementia Treatments

The researchers also uncovered a key molecular pathway that appears to control karyoptosis. They found that forcing proteins inside neurons to clump together, a hallmark of many neurodegenerative diseases, can trigger this destructive process.

According to the study, the buildup of toxic proteins destabilizes the outer membrane of the nucleus, causing it to shrink and eventually disintegrate.

The team then investigated proteins known as kinases, which act as molecular switches in this pathway. In laboratory experiments using rat neurons, blocking these switches reduced markers associated with karyoptosis. In particular, the interaction between the kinase p38 MAP kinase and the protein LaminB1 emerged as a promising target for slowing or preventing the breakdown of the nucleus.

The researchers believe this pathway could eventually lead to therapies that reduce brain cell loss in dementia. Their next goal is to develop ways to selectively target the interaction between p38 MAP kinase and LaminB1 in humans.

"By specifically targeting the interaction between p38 MAP kinase and LaminB1 we may slow down the process of cell death, buying time for more pinpointed therapies against specific neurodegenerative diseases," said Dr. Manolis Fanto, Reader in Functional Genomics, Institute of Psychiatry, Psychology and Neuroscience, King's College London.

Building a Road Map for Future Therapies

"The death and loss of cells in the brain drives many symptoms experienced by people living with dementia. Our study uncovers a new series of chemical events which can coordinate cell death in brain cells. We have started to lay out the road map of how karyoptosis works, and I'm excited to see future breakthroughs this may drive in the dementia research community and beyond," said Dr. Rebecca Casterton, Senior Researcher at the UK Dementia Research Institute at King's and first author on the paper.

"For decades, we've known that toxic proteins build up in Alzheimer's disease and frontotemporal dementia, but exactly how they lead to the loss of brain cells has remained unclear.

"The identification of karyoptosis is a crucial step towards finding targets for treatments that could stop or slow cell loss. It could help widen the window for therapies that tackle the underlying causes of disease, bringing us closer to a cure for dementia. This is why Alzheimer's Research UK funds and supports research," said Dr. Sara Rodrigues, Senior Research Manager at Alzheimer's Research UK.

The study, "Karyoptosis mediates cell death and neurodegeneration upon proteotoxic stress," was published in Nature Communications.

The research was primarily funded by Alzheimer's Research UK and the Biotechnology and Biological Sciences Research Council International Partnership. Additional support came from a studentship provided by the UK Medical Research Council and the UK Dementia Research Institute.

Journal Reference:

1. Rebecca Casterton, Aitana Martinez-Cotrina, Jodi Barnard, Eleanor Wycherley, Yanling Hu, Rhys Anderson, Sebastien Janel, Jiin Byun, Olivia Houghton, Daniel A. Solomon, Juan Alcalde, Frank Lafont, Marc-David Ruepp, Frank Hirth, Bart Tummers, Yong-Yeon Cho, Gian De Nicola, Sarah Mizielinska, Manolis Fanto. Karyoptosis mediates cell death and neurodegeneration upon proteotoxic stress. Nature Communications, 2026; 17 (1) DOI: 10.1038/s41467-026-73802-w

Courtesy:

King's College London. "Scientists may have finally found how Alzheimer's kills brain cells." ScienceDaily. ScienceDaily, 5 July 2026. <www.sciencedaily.com/releases/2026/06/260626124701.htm>.