Scientists found that the protein that causes Alzheimer's spreads like the flu in the brain, infecting neuron after neuron like a virus. The discovery was made by a team from the University of Cambridge who used two types of brain scans to conduct their research, Science Mag reports.
The team scanned 17 patients and found that the Alzheimer's-causing tau protein would concentrate in regions of the brain that were highly connected to others. The protein then uses the wiring of the brain to spread to other neurons. According to Science Magazine, this "transneuronal spread" was previously observed in tests on mice but this is this first time that evidence of its existence has been found in humans.
"We come down quite strongly in favor of the idea that tau is starting in one place and moving across neurons and synapses to other places," said clinical neurologist Thomas Cope, who is one of the study's authors.
While some neurologists agree that the new research is groundbreaking, others are advising caution. Their reluctance to wholly embrace the findings stems from the study's failure to track its test subjects over time, Science Magazine notes. This gap in the research makes it more difficult to conclusively prove that Alzheimer's is worsened by the transneuronal spread. Other neurologists appreciated that this study gives them deeper insight into the brain-wide impacts of the spread of Alzheimer's as regions of the brain lose their connectivity. Previous research on mice only showed the effects from synapse to synapse.The full text of the study has been published in the journal Brain (A Journal of Neurology). In the conclusion of the report, the team states that they believe their research will help to update clinical trials and change the therapies that are currently used to treat Alzheimer's.
Alzheimer's is a chronic neurodegenerative disease that worsens over time. It typically causes memory loss and the breakdown of cognitive ability. According to the Alzheimer's Association, it's the sixth most prevalent cause of death in the United States. The disease is responsible for 60 to 80 percent of the dementia cases in the United States. Advanced age is a risk factor, as most people with the condition are 65 years and older. However, they estimate that 200,000 Americans under 65 have early-onset Alzheimer's. Some of the warning signs include memory loss that affects daily life, changes in the ability to plan or solve problems, and confusion related to time or place.