By John LaMattina, Contributor Alzheimer’s Disease (AD) R&D might be the most challenging therapeutic area that faces medicine today. It is known that AD is caused by the build-up of proteins into clusters that clog up nerve cells in the brain. These “plaques” break down nerve cells which, in turn, results in a decrease in the ability of these cells to function thereby leading to the familiar AD symptoms of memory loss and erosion of cognitive skills.