For decades it was believed that the brain ceased to grow new cells after we reached a certain age.  The brain was considered an exception to the rule that our bodies constantly replenish cells.  Recent research at Princeton University and elsewhere has demonstrated that some parts of the brain do indeed grow new brain cells.  

Elizabeth Gould and Charles Gross performed their research on rhesus monkeys, whose brain structure is very similar to that of humans.  They found that neurogenesis -- the formation of new nerve cells -- takes place in several different regions of the cortex that are crucial for cognitive and perceptual functions. The cerebral cortex is the most complex region of the brain and is responsible for high-level decision making and for learning about the world. The results strongly suggest that the same process occurs in humans. Their report is published in the Oct. 15, 1999 issue of Science.

So what?  

Do we lose brain cells as we get older?  Scientists know that most of us lose brain mass as we get older.  CT scans of older adults often show some degree of cerebral atrophy - brain shrinkage.  There is also research that suggests that we lose connections between brain cells as we age.  My father is beginning to have difficulty remembering names.  They usually come to him eventually, but they do not seem to be as easily retrieved as in the past.  The name is still stored, it's just not easily accessed.    

Can anything be done about this?  Are we destined to lose our faculties as we age?  There is some hope on several fronts.  Recent research on Alzheimer's Disease suggests that there might some day be a vaccine that protects us from Alzheimer's build-up of plaques and tangles in our brains.  Some studies suggest that physical exercise keeps brains healthy.  There is also research that suggests that we can keep our brains working well by using them regularly.  This is the principle behind a recent book by Lawrence Katz, Ph.D. and Manning Rubin.  Katz is a neuroscientist at Duke University who studies brain aging.  Their book, Keep your Brain Alive, describes practical exercises that anyone can do to keep the brain working at top efficiency.  Eating or brushing your teeth with your non-dominant hand, for example, allows your brain to use pathways that are not frequently accessed.  

As research progresses we will undoubtedly see additional studies demonstrating ways to keep our brains healthy.  We can already take advantage of the early work in this field.

Links:

Another Study finds New Brain Cells - from Doctor's Guide

Keep Your Brain Alive: 83 Neurobic Exercises to help prevent memory loss and increase mental fitness
by Kawrence Katz, Ph.D. & Manning Rubin
Easy to read and based on the latest science.  This book may help you slow brain aging.

What do you think?