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Inside Alzheimer’s Disease

Neutron and x-ray experiments reveal conditions that lead to the disease’s signature tangles and plaques in the brain
March 12, 2015
Inside Alzheimer’s Disease

Neuron membrane disruption may underlie Alzheimer’s disease.

Alzheimer’s disease is America’s sixth-largest killer and burdens the nation to the tune of $220 billion per year—more than one percent of GDP—plus another 17 billion hours of unpaid care, according to the U.S. Centers for Disease Control and Prevention and the Alzheimer’s Association.

In the brains of patients suffering from Alzheimer’s disease—examined post-mortem, of course—anomalous tangles of tau proteins and plaques of beta-amyloid protein fragments are always present. These proteins are present in healthy human brains as well, where they help stabilize microtubules in the nervous system and participate in cell growth, respectively. The question is, what causes them to accumulate into tangles and plaques in the brains of those suffering from the disease? Something must be catalyzing the aggregation of tau and beta-amyloid molecules out of solution in Alzheimer’s patients, and a theory that has been gaining traction suggests that electrical charges on neuron cell membranes may provide that catalyst. The Lab’s Jarek Majewski put that theory to the test with x-ray and neutron beams to reveal important variations in the membrane structure under different electrical-charge configurations.