In Alzheimer's Disease, which is not a normal part of aging, abnormal clusters of protein fragments, called plaques, build up between nerve cells. (Credit: National Institute on Aging)
What happens to the brain as we age? Is it possible to ward off age-related changes? What’s the best way to keep the brain healthy? Those are some of the questions researchers are striving to answer about aging and the brain. And they are making some tantalizing discoveries, top among them the degree to which the brain remains adaptable. New neurons are born throughout our lifetimes via a process called adult neurogenesis, particularly in the hippocampus, a brain region involved in learning and memory (See “Memory”). But exactly what these new neurons are doing remains an open question. More recent research, in mice, has shown that young blood can reverse cognitive decline with age. Work is underway to pinpoint the blood-borne factors that are responsible. In the meantime, however, evidence is mounting that a healthy diet and exercise are more effective than brain training games at keeping older brains sharp.
As the population ages, the total number of people with dementia, including Alzheimer’s Disease, is expected to increase. As a result, researchers and medical doctors are working to find ways to diagnose dementia early and to develop effective ways to prevent and treat it. However, progress has been slow. For example, all of the clinical trials for Alzheimer’s drugs have failed, leading many scientists to call for greater investment in basic research into the various causes of dementia and how it progresses.
For most of us, a declining memory is a normal consequence of growing old. But why? What’s happening in the brain that causes age-related memory decline, and is there anything we can do to slow this decline?
New findings reveal memory networks more intricate than previously believed. Understanding these pathways may help develop ways to enhance learning, mitigate memory disorders such as Alzheimer’s or guard against memory loss from aging.
Recent research is beginning to answer these fundamental questions by exploring the plasticity of the adult brain—its ability to readily be shaped by experience. Contrary to the common assumption that you can’t teach an old dog new tricks, there is increasingly strong evidence that the adult human brain is remarkably malleable and capable of new feats even in the last decades of life.