Neuroscientists at the University of Southampton have made a significant development in understanding how Alzheimer's disease spreads in the brain, discovering a significant period of time when medical intervention could stop its onset.
A hallmark of Alzheimer's disease is the accumulation of tau proteins in neurons that cause brain volume loss. This accumulation, known as neurofibrillary tangles, is formed when a sick version of tau bends incorrectly. Before this research, published today in the Journal of Neuroscience, very little was known about the timing of this process and how poorly folded tau proteins spread to other cells.
Studying this in a human brain would be too complex, so the Southampton team created a circuit of murine neurons grown in a cell culture and introduced diseased tau proteins into these cells. Scientists observed that the tau spread very quickly to other neurons and began to fold back and accumulate. However, despite the accumulation of tau, it did not cause aggressive damage and both donor and accepting neurons remained functional and able to send electrical messages.
Dr. Katrin Deinhardt, professor of Neuroscience at the University of Southampton who oversaw the research, said: "We saw that an incorrect tau fold was not immediately toxic and that the affected cells could tolerate ; accumulate better than we expected. This is a really positive result and shows that there is a time window in which therapeutic intervention could take place to save neurons with tau pathology. "
Grace Hallinan, a PhD student at the University of Southampton when she conducted this study, added: "We were really excited to find that neurons with badly folded tau could stay healthy, because this suggests that they could be saved before the occurrence of cell death leading to brain shrinkage and memory problems. We hope that our results will encourage further research in this therapeutic window in order to slow down or even halt the progression of Alzheimer's disease "
Dr. James Connell, head of research at Alzheimer's Research UK, said: