by Evan Lavelle
Neuroscientists used to think that brain cells would stop growing once a person reached adulthood. For most parts of the brain, this is still agreed to be the case. However, recent research suggests that one area of the brain, called the hippocampus, can continue to develop even after someone has reached adulthood. The hippocampus is located near the center of the brain and is associated with long-term memory and learning. The word is derived from the Greek term for “seahorse.” If you look closely at the shape of this brain region, you might be able to see the resemblance.
Because the brain of a rat is actually quite similar to our own in many ways, they served as the model organism for this study. That means the researchers think they can learn something about humans by testing them. For this study, the rats were separated into three groups, each with its own special exercise program. The first group did only aerobic training (running on a treadmill). The second practiced only resistance training (climbing a ladder with weights attached). The last group performed high-intensity interval training (short sprints with periods of rest).
After seven weeks, the rats were tested to see if their physical ability had improved and if there was any effect on the hippocampal cell count. The rats who exercised with weights became noticeably stronger, but did not show a significant increase of brain cells in the hippocampus. The rats who did high-intensity interval training became faster and actually developed a measurable amount of new brain cells in the hippocampus. The rats who engaged in aerobic exercise, however, were the clear “winners” of the study. They became almost as fast as the rats that ran short sprints, but they also saw the biggest climb in hippocampal cells.
Being that the hippocampus is so important to memory, it also has a huge role in learning. Unfortunately, brain cells in the hippocampus are slowly lost over the course of one’s life in response to stress and anxiety. While several studies have been performed to show an association between general exercise and a healthy brain, these findings are noteworthy in that they determine what particular type reaps the greatest benefit. Because the research wasn’t performed on humans, it can’t be said for certain that we would show the same results as the rats did. It’s a good guess, though, that sustained aerobic exercise is not only good for your health and endurance but also your mind.
Evan Lavelle is a graduate of Northern Arizona University’s biology program and is now studying to earn a bioinformatics master’s degree at New Mexico State University. He is currently pursuing research in the area of artificial neural networks.
