Scientists Identify Immune Pathway Outside Brain That May Trigger Alzheimer's Damage

For generations, Alzheimer's disease has been understood as a tragedy unfolding within the brain itself — a slow interior collapse of protein and memory. Now, a team of researchers publishing in Nature has traced a thread of causation outward, finding that immune cells circulating in the body may activate a cascade that worsens the very neurodegeneration long thought to be purely a brain problem. The discovery invites a humbling revision: that the mind's unraveling may be shaped, in part, by forces operating far from the skull, in the broader immune landscape of the body.