Dementia is a serious brain condition that affects millions of people around the world. It causes a gradual loss of memory and thinking skills. People with dementia may become confused, forget things easily, and have trouble doing everyday tasks. Despite many years of research, scientists still do not fully understand what causes dementia, and sadly, there is no cure yet.
Most research in the past has focused on brain cells called neurons. Neurons are the main cells responsible for sending messages in the brain. However, a new study from scientists at Weill Cornell Medicine has found that another type of brain cell—called astrocytes—may also play a major role in causing memory problems.
Astrocytes are star-shaped cells that have long been seen as helpers to neurons. They provide support and help keep the brain’s environment healthy. Until now, they were not thought to play a direct role in memory loss or dementia. But the new study challenges this old idea.
The scientists discovered that when a certain protein, called TDP-43, builds up in astrocytes, it can cause memory loss—even if the neurons themselves are still healthy. TDP-43 is a protein that has been found in the brains of people who had Alzheimer’s disease or a related condition called frontotemporal dementia.
The researchers looked at brain tissue samples from people who had died with these conditions. They noticed that the TDP-43 protein had gathered inside astrocytes in the hippocampus, a part of the brain that is very important for memory.
To better understand what was happening, the researchers also studied mice and brain cells in the lab. They found that when TDP-43 built up in the astrocytes of mice, the animals started to lose their memory over time. Interestingly, the mice did not show other changes in behavior, which means that memory loss was the main problem.
The study also uncovered a strange reaction happening in the astrocytes. Even though there was no infection, the astrocytes were acting as if they were fighting off a virus. They started to release immune chemicals known as chemokines.
These chemicals then triggered nearby neurons in the hippocampus to become too active. This overactivity seems to be linked to the memory problems observed.
This discovery is important because it shows that astrocytes can cause dementia symptoms without any damage to neurons. It suggests that immune changes in these support cells alone may be enough to harm memory. This gives scientists a new target for treatment. If they can calm down the immune response in astrocytes, they might be able to slow or stop the memory loss.
Even more promising is the fact that some drugs already being tested for other diseases, like arthritis, could help. These drugs block a chemical receptor called CXCR3, which was found to be involved in the chain of events leading to neuron overactivity.
Because these drugs are already in clinical trials, they might be approved faster for use in dementia if they prove effective.
While we wait for more studies and better treatments, there are still things people can do to protect their brains. Regular exercise helps improve blood flow to the brain. A healthy diet, especially one with fruits, vegetables, and healthy fats like the Mediterranean diet, can support brain health.
Keeping the brain active through learning, reading, or puzzles is also helpful. Staying socially connected and managing stress, getting enough sleep, and controlling health problems like high blood pressure or diabetes can all lower the risk of dementia.
This study, led by Dr. Avital Licht-Murava and her team and published in Science Advances, gives us a deeper understanding of what might cause memory loss in dementia. It reminds us that the brain is complex, and that many types of cells—not just neurons—play important roles. It also gives us hope that new treatments could be on the way.
If you care about dementia, please read studies that eating apples and tea could keep dementia at bay, and Olive oil: a daily dose for better brain health.
For more health information, please see recent studies what you eat together may affect your dementia risk, and time-restricted eating: a simple way to fight aging and cancer
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