Neurogenesis and Exercise

NEUROGENESIS LITERALLY MEANS "BIRTH OF NEURONS." It's the term used to describe the generation of new neurons within the brain. For many years, it was believed that the brain was a fixed organ, simply deteriorating over time. Unlike other parts of the body, the brain was believed to be incapable of regenerating itself. Over the last decade, multiple studies have shown that the brain is in fact capable of generating new neurons. Even more recently, it has been proven that exercise can increase this production.

Neurons..."what are those again?"

Neurons are tiny cells in the brain that are responsible for transmitting and processing information. They do this by sending and receiving electrochemical impulses to each other through small spaces called synapses. There are literally billions of them in the human brain.

Anatomy of a Neuron

Basic anatomy of a neuron.

Neurons look like small wires with frayed endings that reach out like branches on a tree. The vast network of neurons within the brain is like an incredibly complex highway that transports information for nearly every thought, impulse, or feeling that passes through our heads.

In degenerative diseases like Alzheimer's, neurons deteriorate and these neuronal networks start to die off, resulting in diminished cognitive function. With this in mind, it's not difficult to see why many might be interested in the possibility of new neuron growth.

Where does this "Neurogenesis" happen?

Neurogenesis has been seen and documented in the dentate gyrus of the hippocampus (Kemperman,1999). The hippocampus is an important area for memory. It is believed that the hippocampus is the part of the brain where memory consolidation takes place.

The Hippocampus

The location of the Hippocampus within the human brain.

To date there have been studies showing Neurogenesis within the Hippocampus in both rats and humans. In order to see this new neuron growth, scientists use a chemical substance called bromodeoxyuridine (BrdU). This marker allows new neurons to be seen and distinguished from preexisting neurons.

Mice in a wheel

Mice at the gym.

The Role of Exercise

Exercise, particularly running has been shown to dramatically increase the level of Neurogenesis in the adult mammalian brain. Multiple studies with rats have shown that spending time running results in a sharp increase in the number of neurons generated within the hippocampus (van Praag et al. 1999a, b).

These rats also showed improved times in a water maze test as well as a few other similar mental challenges. This suggests that the new neuronal growth may have some impact on this enhanced cognitive function.

It has been well documented that exercise enhances cognitive function, and reduces the chances of heart disease, cancer, and diabetes. Exercise has also been shown to delay the onset of degenerative diseases and slow the effects of memory decline that accompanies aging. Now there may be reason to think that, dare we say...exercise can actually make you smarter.

While that may be a stretch, the hypothesis that neurogenesis plays a large part in the benefits mentioned above is not. More studies are in the works, and further research needs to be done to tell us exactly what the benefits of these new neurons are, and if they can be manipulated to repair or reverse the effects of degenerative disease.

So, for anyone out there who still needs another reason to exercise, you can add neurogenesis to the list.

Neurogenesis and Exercise

Neurons..."what are those again?"

Where does this "Neurogenesis" happen?

The Role of Exercise

Further Reading