Brain matters: The hippocampus

This week I want to talk about the hippocampus. The hippocampus is a seahorse shaped part of the brain that is our memory. It is called hippocampus because that is the Greek word for seahorse. We have one hippocampus in each side of the brain. If our hippocampus fails, our memory fades. It is in our interest to protect our hippocampus.

So what can we do to protect the hippocampus.

For a long while scientists believed that we stop producing brain cells once we reach a certain age. I have seen different age ranges mentioned -some say when we reach adulthood; others say the brain produces cells until the ages of between thirty two and thirty five. What has been agreed however is that at our peak, we have almost ninety billion brain cells and that the average person loses about three million cells a day. If you are a smoker, if you drink excessively or you can’t control your diet, you lose more brain cells.

So can anything be done to generate new brain cells -especially in the hippocampus?

Neurogenesis is the process by which new neurons are formed in the brain. This takes place mainly when the embryo is in a mother’s womb and when the baby is first born. It was always believed that signals from the brain are transmitted to other parts of the body. However, groundbreaking research performed by Dr Rita Levi Montalcini, an Italian Jewish scientist during World War II led scientists to believe that the body can also send signals to the brain resulting in new brain cells being formed. This was called nerve growth factor and for her research and her discovery, Dr Montalcini was awarded the Nobel Peace Prize in 1986.

What does this mean for us? It means, if we were to exercise for example, we can actually increase the size of our hippocampus. This was confirmed by research carried out by the University of Illinois in Chicago. They asked 120 adults to exercise three times a week for thirty minutes each time. After one year, they found that the hippocampus of these adults had increased in size! But it is not just any exercise. It should be exercise that the individual enjoys and does not feel forced into doing. Professor Carl Cotman, a scientist at the University of California performed research on three groups of rodents -one group were kept in a location and not allowed to exercise for a period of time; one group was forced to run on a treadmill and one group was given freedom to choose when to exercise. Professor Cotman found that the third group who could decide when to exercise released a hormone called Brain Derived Neurotropic Factor or BDNF which encourages nerve cells in the brain to grow and connect.

“I think it (exercise) is keeping the brain healthier, longer” says Professor Cotman.

There are other activities which we can do which promotes neurogenesis. Another simple one is learning. The brain loves to learn new things. The more you learn, the healthier the brain. It can be something as simple as a jigsaw puzzle or learning new facts. This was demonstrated by experiments carried out on trainee black cab drivers in London. Getting a license to drive a black cab is one of the most difficult things to undertake. It requires learning the name of every street in London, and the best way to get there. The course is called The Knowledge and it takes a minimum of four years to get a license. Experiments done on these trainees found that the size of the hippocampus of those who passed the test had increased between the time they started the course and qualified as a taxi driver. These experiments proved that contrary to earlier beliefs, it is possible to reverse the aging of our memory.

So whatever your plan is for each day, schedule at least thirty minutes of exercise. And challenge your brain by learning something new.

Perhaps take a course about the brain!?