Many people experience memory loss as they age. In the past, neuroscientists-doctors who study the brain-had theories about how the brain contained only a certain number of cells and how, over time, these cells might get used up. More recent research suggest that the brain may continue to manufacture new brain cells throughout a lifetime. Also,there is now evidence that damage to the hippocampus an area of the brain thought to be important in the process of recalling information may play an important role in memory loss. Studies conducted on patients who have suffered damage to this area of the brain show that while they can still recall memories stored before the brain was damaged, they are unable to remember new facts. In addition, diseases associated with old age,(such as Alzheimer's,) and other problems involving short- and long-term memory loss, are now being traced to possible damage to the hippocampus.