What Causes Alzheimer's? Research Has New Answers

Globally, there are an estimated 44 million people with Alzheimer's disease and dementia, and by 2050, the number of people age 65 and older who have Alzheimer's will increase by 68 percent, mainly in low and middle-income countries.

One of the most common kinds of dementia, Alzheimer's Disease (AD) is a neurodegenerative disease. While the symptoms are often quite mild at the onset of the disease, they gradually progress to take on a more severe form and only 1 in 4 people with Alzheimer's are diagnosed [1].

The cause of Alzheimer's disease is thought to be the abnormal buildup of proteins in and around brain cells. While it is still unknown exactly what causes this process to begin, scientists know that it occurs many years before symptoms are evident [2].

Recently, researchers found that swelling caused by amyloid plaques in the brain may be the true cause of Alzheimer's disease. Find out more about what causes Alzheimer's [3].

What Causes Alzheimer's?

Here are the important points from the study:

Point 1: A team of Yale University researchers conducted a study on mice to investigate if swelling caused by amyloid plaques may be the true cause of Alzheimer's disease.

Point 2: When a number of proteins are linked together, the resulting protein can begin to behave abnormally. This is because the proteins lose their normal shape. They also misfold together, forming larger structures known as amyloid plaques [4].

Point 3: According to the study, each amyloid plaque in the brain results in swelling of nearby axons, the very thin cables that link neurons in the brain.

Point 4: Researchers believe that dementia occurs when the axons become swollen, preventing information from moving from one area of the brain to another [5].

Point 5: As a result of swelling in the axons, an electric current sink, similar to an electrical circuit, is created, which prevents normal transmission of electrical signals through the axons, disrupting communication with hundreds of other neurons.

Point 6: Since each amyloid plaque is surrounded by hundreds of axons with swellings and each axon is connected to hundreds of other neurons, and given that millions of amyloid plaques are located in Alzheimer's disease brains, these swelling mechanisms may disrupt billions of connections in the brain.

Point 7: Furthermore, the researchers identified a potential new biomarker related to Alzheimer's disease, PLD3, which is a protein in lysosomes that causes lysosomes to cluster along the axon of neurons causing swelling.

Point 8: With gene therapy, PLD3 swellings are reduced and this improves electrical conduction in axons as well as communication between different neurons that are connected through those axons [6].

On A Final Note...

Researchers believe that PLD3 may be useful as a biomarker to diagnose Alzheimer's disease, as well as a therapeutic target in the future.