When the Brain Is Ill, but Memory Holds On

Alzheimer’s Symptoms May Arrive Late

First, the small things disappear: a forgotten word, misplaced keys, important dates that slip away. Then Alzheimer’s symptoms enter everyday life more forcefully. They take away memory, confidence, and independence. That is why the discovery made by scientists in the United States may prove so important. It turns out that some people may already have brain changes typical of Alzheimer’s, yet show no clear symptoms for a long time.

Alzheimer’s Research Reveals a Memory Paradox

This paradox has troubled researchers for years. Why does the disease quickly steal memories and independence from some people, while similar changes in the brain barely alter the lives of others for a long time? Scientists from the University of California set out to answer that question.

To do so, they carried out research into Alzheimer’s disease. Using artificial intelligence, they analysed data from the brains of people who had symptoms linked to Alzheimer’s. This allowed them to identify a kind of “fingerprint” of the disease: a characteristic pattern of changes that may relate to how it develops. They then conducted tests on mice, both healthy animals and those bred to develop brain pathologies similar to those seen in Alzheimer’s disease.

CgA Protein May Protect Memory

The experiment showed that this “fingerprint” may distinguish between different courses of the disease. But that was not the only conclusion to emerge from the Alzheimer’s research. Scientists focused on the protein CgA, or chromogranin A. It may act as an important switch in the brain and influence whether disease-related changes translate into problems with cognitive function.

When researchers bred mice without the protein associated with the emergence of symptoms, they found that the sick animals still developed changes linked to Alzheimer’s disease. Even so, the characteristic symptoms did not always appear. The latest results, described in the scientific journal Acta Neuropathologica Communications, suggest that CgA may be an important indicator of whether the disease will produce visible symptoms. This does not mean, however, that scientists already have a ready-made treatment for Alzheimer’s disease.

Sex Changed the Outcome of the Experiment

There is another very important detail. Researchers found clear differences between male and female animals. Male mice without CgA did not have problems with learning and memory. Females, meanwhile, not only avoided similar problems, but also had less of the brain damage typical of Alzheimer’s disease. Researchers do not yet know why this happened, but they do have a theory.

The most likely explanation lies in differences in hormone levels, the immune system, or genetics. Whatever the reason for these disparities, the results from the American scientists matter greatly. In the future, this new knowledge may help researchers develop more effective therapies based on limiting the activity of CgA. And that matters to us in a very particular way.

139 Million People With Dementia by 2050

According to a report by Poland’s National Health Fund, more and more people in Poland are living with Alzheimer’s disease. The report, prepared in 2019, states that over 5 years, the incidence of the disease rose by as much as 12 percent. What is more, the number of patients continues to grow.

Around 55 million people worldwide currently live with dementia. By 2050, that number will exceed 139 million. Alzheimer’s disease is one of its most common causes. Developing a new therapy could improve quality of life for a growing number of patients, and perhaps even extend their lives. For now, however, the discovery matters because it helps explain why Alzheimer’s symptoms may appear later in some people than the disease changes visible in the brain.

Read this article in Polish: Mózg chory, ale pamięć działa. Nowy trop w chorobie Alzheimera