Neurogenesis
Boost your brain… use your brawn by/from Telegraph Media Group telepraph.co.uk-Exercise appears to directly affect a region of the hippocampus, the area of the brain concerned with memory and learning, called the dentate gyrus, one of the few areas of the brain where neurogenesis – the creation of nerve cells – takes place. Building up the number of nerve cells (neurons) and the connections between them in the dentate gyrus is vital to the prevention of memory decline that typically begins at around the age of 30. So does this mean that aerobic exercise can help anyone increase their learning potential?
Cell production is a complex affair relying on a ready supply of proteins and hormones, particularly a hormone called Insulin-like Growth Factor 1 (IGF-1). IGF-1 is known to be crucial in child growth and the development of every cell in the body. It is released into the bloodstream every time you contract and relax a muscle and so levels rise when you exercise.
When IGF-1 reaches the brain, it acts on the cells that release neurotransmitters, the chemicals responsible for communication. It triggers an increase in production of brain-derived neurotrophic factor or BDNF, which promotes the growth of new nerve cells and which Harvard psychiatrist, John Ratey, has nicknamed “Miracle-Gro for the brain”.
As new brain cells are created, they form pathways and links, as we learn new facts and skills. The greater level of BDNF you have, the more new nerve cells you can produce and the greater the number of building blocks available to you to extend your learning capacity. But if levels fall, it can work in reverse. Those born with a faulty variant of the gene responsible for the production of BDNF have trouble with recall and creating new memories.
Using an MRI scanner, the Columbia researchers led by Professor Scott Small examined a living brain before and after exercise and, for the first time, were able to see neurogenesis effectively in action.
Those most likely to benefit from the finding are victims of degenerative brain disorders such as Alzheimer’s, and the next step will be to use this information to create an exercise regime specifically tailored to preventing age-related memory loss.
Professor Bruce Lynn, from University College London, welcomes the new findings. He recalls similar findings being presented in the 1960s – and then ignored by the scientific community. Even five years ago, he says, there were only half a dozen papers on the topic; yet now it has become a very active area for research, as it has become abundantly clear that those who remain physically active stay cognitively fit, too.
“The big question however,” says Prof Lynn, “is what is the link? It is not obvious why exercise has this effect on the brain. Growth factors are important but blood flow to the brain is not relevant. Some people suggest increased oxygen is crucial but our blood is always saturated with oxygen unless we’re in the Himalayas – or, ironically, exercising.
“What type of exercise you choose seems to matter: aerobics works, but you don’t get the same results from strength training. However, when you are strength training – using weights – you see big increases in the production of IGF-1.”
At the University of Birmingham, Professor Asker Jeukendrup, a specialist in exercise metabolism, confirms there is a lot of evidence that physical activity helps brain development. He thinks there is some truth to the theory that suggests improving blood supply and therefore fuel to the brain is important.
“You don’t need to do much to get an effect,” he says. “Studies have already shown that just 20 minutes walking – not even particularly briskly – will reduce degeneration of the brain and improve learning ability. Yet many people are still below that threshold. And, of course, other studies show that the more you do, the better it gets.”
There are a couple of points from this I will comment on further in future posts. First is exceices has the potnetial increase the sizes of the arties which supply blood to the brain as the the body will feed its viatal oragans (sucg as the brain) fisrt when fast with an oxegine defict. This can result in permaenet strecnhing of those arties, which is a good thing. Second, optmial amount of phsical stress can trigger the right hormal reactions connected with growth factors.
Leave a reply to Neurogenesis from exercise