Blood Clotting and Alzheimer's

A Gladstone Institutes study found that fibrinogen, a key blood coagulation element, plays a role in a molecular and cellular chain reaction that leads to the loss of memory storage neurons within the brain, reports News-Medical . Leakage of fibrinogen from the blood activates microglia and causes them to attack and destroy neurons at the synapses. The researchers generated the first three-dimensional volumetric images of Alzheimer's disease (AD) in humans and mice, then engineered the mice to prevent fibrinogen leakage and maintain microglial dormancy, thus shielding the brain against memory loss. Surprisingly, fibrinogen's presence in healthy brains triggered the same type of changes as in AD, but without any evidence of amyloid plaques. This adds credence to the theory that two separate mechanisms could be inducing dementia. Alternatively, both pathologies could be connected, as people with AD or vascular dementia exhibit deteriorated cognition, while those with both conditions suffer far worse declines than for either disorder alone.