Alzheimer's disease is a type of dementia that involves the death of many of the nerve cells in the brain that are involved in memory, learning and thought. These nerves normally release a substance called acetylcholine. Thus, people with Alzheimer's have a deficiency of this substance, but they also have twisted fibers in the nerves of the brain composed of a tau protein, areas made of beta amyloid and abnormalities involving calcium.
What is Alzheimer's Disease?
Alzheimer's disease is the most common reason for dementia in the elderly population, per Thomas Bird, M.D., Professor of Neurology and Medicine at the University of Washington in "Harrison's Principles of Internal Medicine." Neuroscience has determined that in Alzheimer's, people have areas in the brain called plaques that are made of a protein named beta amyloid. This amyloid protein can also accumulate in the walls of the arteries in the brain. They may also have areas in the brain that have wasted away, other areas that have become too large, and have tangles of twisted fibers of a tau protein inside the nerve cells of the brain.
Statistics
According to the Centers for Disease Control and Prevention, or the CDC, approximately five million American men and women have this disease. Although young and middle-aged people can develop Alzheimer's disease, most do not start to have symptoms until they are at least 60 years old. The CDC estimates that five percent of people aged 65 to 74 years old may have Alzheimer's, while as many as 50 percent of people who are 85 years old or older may have it.
A Calcium-Conducting Channel and Alzheimer's
In the July 2008 issue of "Neuron," Kim Green of the University of California writes about a new discovery involving Alzheimer's. Researchers have found a channel, or opening, in the nerve cells of the brain which they have named CALHM1. It is called a calcium-conducting channel, because it is a channel that lets calcium pass through it. They also determined that problems with the passage of calcium through this CALHM1 channel might affect the production and breakdown of the beta amyloid and tau proteins.
Calcium Waves and Alzheimer's
In a study conducted by a group of bioengineers at the University of California at San Diego, as reported in the December 2009 issue of the "American Society for Neurochemistry," beta-amyloid plaques taken from the brains of rats started waves of calcium in rat brain nerve cells. These researchers feel that this result shows that having a better understanding of calcium, calcium waves and a calcium balance is important for determining what causes Alzheimer's disease.
References
- American Society for Neurochemistry: Amyloid β-peptide directly induces spontaneous calcium transients
- Centers for Disease Control and Prevention: Alzheimer's Disease
- "Harrison's Principles of Internal Medicine"; Anthony Fauci, M.D., Dennis Kasper, M.D., Dan Longo, M.D. et al.; 2008
- Neuron: Linking Calcium to Aβ and Alzheimer's Disease
