This research, which was just published in the journal Brain, supports the idea that some parts of human blood can affect neurogenesis, which is the process of making new brain cells. The hippocampus is an important part of the brain that helps us learn and remember things. Neurogenesis takes place in the hippocampus.
In the past, autopsies were the only way researchers could look at neurogenesis in the later stages of Alzheimer’s. Even though it is known that Alzheimer’s disease stops new brain cells from growing in the hippocampus in the early stages of the disease.
Researchers took blood samples from 56 people with mild cognitive impairment (MCI) over the course of several years. MCI is a condition in which a person’s memory or cognitive abilities start to get worse. So they could understand the early changes, this was done.
People with the condition get Alzheimer’s disease at a much higher rate than the rest of the population, even though not everyone with MCI will get Alzheimer’s disease in the end. 36 of the people who took part in the trial and were later checked out were found to have Alzheimer’s disease.
Dr. Aleksandra Maruszak, one of the joint first authors of the paper from King’s IoPPN, says, “In our study, we treated brain cells with blood from people with MCI.” “As Alzheimer’s disease got worse, we looked at how these cells changed in response to blood.”
When they looked into how blood affected brain cells, the researchers made a number of important discoveries. Over the years, blood samples from people who eventually got Alzheimer’s disease showed a decrease in cell growth and division, as well as an increase in apoptotic cell death. This happened because of the fact that (the process by which cells are programmed to die).
Researchers did notice, though, that using these samples led to a rise in the number of immature brain cells that turned into hippocampal neurons.
The researchers think that the increased neurogenesis may be an early way to make up for the loss of brain cells that people with Alzheimer’s disease experience due to neurodegeneration. But the researchers haven’t been able to figure out why there are more neurons being made.
The study’s lead author, Professor Sandrine Thuret from King’s IoPPN, said, “Previous studies have shown that hippocampus neurogenesis can be boosted by blood from young mice to improve the brain function of older mice.” This gave us the idea to use human brain cells and human blood to imitate the process of neurogenesis in a dish. In this study, we wanted to use this model to learn about the process of neurogenesis and to predict Alzheimer’s disease based on changes in this process. We found the first evidence that the body’s circulatory system can affect the brain’s ability to make new cells. Our goal was to figure out if someone had Alzheimer’s disease based on these changes.
When the researchers looked at only the blood samples that were taken the most time before the subjects were diagnosed with Alzheimer’s disease, they found that the changes in neurogenesis happened about 3.5 years before a clinical diagnosis of Alzheimer’s disease.
One of the study’s co-first authors, Dr. Edina Silajdi, said, “Our findings are very important because they could help us predict the start of Alzheimer’s disease early without having to do any invasive procedures.” This could be used with other blood-based biomarkers that show the traditional symptoms of the disease, such as the buildup of amyloid and tau, which are known as the “flagship” proteins of Alzheimer’s disease.
One of the study’s co-first authors, Dr. Hyunah Lee, said that “it is now important to confirm these results in a larger and more diverse group of people.” The blood test we used could be used in a lot of different ways, and we are really excited about them. For example, it can help divide people with memory problems into groups so they can take part in a clinical study of Alzheimer’s disease drugs that change the way the disease works.
Researchers say that these findings may give them a chance to learn more about the changes that happen in the brain during the early stages of Alzheimer’s disease.