Alzheimer's-linked protein crucial for long-term memory: study

Scientists in Australia have identified a key role for the Alzheimer's-linked protein tau in shaping long-lasting memories, offering new clues for future dementia treatments, reported Xinhua. The research, published in Nature Communications, found that tau is essential for organizing and stabilizing memories so they persist over time, although it is not required for initial learning or short-term recall, said a statement from Australia's Flinders University released Monday. Without tau, memories could still form but were weaker and less durable, said the study's senior author and neuroscientist, Associate Professor Arne Ittner at Flinders University. Using mouse models, researchers showed that tau helps organize engram cells -- specialized neurons that form the physical trace of memories -- during the critical encoding window, helping determine which cells are selected to store a memory. The study also found that tau helps prevent excess or noise activity in the brain, ensuring only specific cells are recruited to store a memory, resulting in clearer, more stable memories. A subtle chemical modification of tau, called phosphorylation, was identified as a key mechanism that coordinates engram cell activity. While abnormal tau phosphorylation is a hallmark of Alzheimer's disease, the study shows that controlled, low-level phosphorylation is essential for normal brain function. Researchers said disease-associated forms of tau interfered with both new memory formation and recall, pointing to how dementia-related memory loss may arise from impaired organization and retrieval rather than memory storage alone.