Alzheimer's is a devastating neurological condition that affects many people, usually in their old age. It is signified by memory loss, dementia, among other cognitive difficulties. A new study from the Mayo Clinic has given scientists potentially vital information in the attempt to find a cure. (via ScienceAlert)
When studying the disease, two primary causeswere implicated, tau and amyloid beta. And for many years the focus of both diagnostics and research into Alzheimer's has primarily focused on amyloid beta. The proper functioning of this protein is unknown, although some animal studies have linked it to a potential immune function or cholesterol regulation within the brain. (via MedicalXpress) Scientists do however know what happens when it malfunctions. Misfolded amyloid beta proteins build up around the neurons as a plaque, interfering with them and eventually killing them.
While this mechanism is extremely damaging, and important to Alzheimer's, and other neurological conditions, it may not be the main culprit. The new study identified the tau protein as a much more crucial component of Alzheimer's. Similar to amyloid beta, those with Alzheimer's appear to have misfolded tau that builds up and spreads throughout the brain. This also leads to the neuron death, as the tau protein normally assists in the transport of materials within neurons.
They made this somewhat surprising discovery by examining 3600 postmortem brains that had been donated to science. 1375 of them were confirmed to have Alzheimer's at their death, and they died at different stages of the disease. By examining the brains directly, and any scans of the brain before their death, the scientists were able to create a timeline of the disease.
Initially, buildup of amyloid was a clear indicator of cognitive decline. But they found that that link was greatly disrupted when malfunctioning tau protein was also factored in. This indicated that tau was in fact the driving force behind the disease. Another supporting factor was that malfunctioning tau seemed to spread from the memory centers of the brain outward into the cortex, mimicking the progression of the disease. Whereas amyloid beta generally spreads in the opposite direction. Amyloid beta can also be found in some brains that don't show signs of cognitive decline.
This study is certainly big news for the world of Alzheimer's research. The scientists still recommend amyloid beta be part of Alzheimer's diagnostics and research, but that the focus definitely needs to be shifted into other avenues. Still this is only one study, and there are still many things that need to be discovered before we can properly tackled this disease.
