Brain self-protects when running on empty
U. LEEDS (UK) — When running low on energy, the brain is able to protect itself from harm by triggering a protein that reduces the frequency of electrical impulses.
Published in Proceedings of the National Academy of Sciences, the findings could lead to new treatments for patients who are at risk of stroke because their energy supply from blood vessels feeding the brain has become compromised.
Many regions of the brain constantly consume as much energy as leg muscles during marathon running. Even when asleep, the brain needs regular fuel. Much of this energy is needed to fire up action potentials, tiny electrical impulses that travel along nerve cells in the brain that trigger the release of chemical messages at nerve endings, allowing the brain to process information and control bodily functions.
Normally, the bloodstream supplies enough glucose and oxygen to the brain to generate enough energy required for these action potentials to be fired up. But things can go wrong if the blood vessels feeding the brain become narrowed or blocked, restricting the supply of vital nutrients.
The energy-sensing protein AMPK was first discovered by Graham Hardie, professor at the University of Dundee. “When we first defined the AMPK system by studying fat metabolism in the liver back in the 1980s, we had no idea that it might regulate completely different functions in other organs, like nervous conduction in the brain,” Hardie says.
“There are drugs currently on the market that stimulate AMPK, which are used to treat other conditions. In future these and other drugs could be given to at-risk patients to give them a better chance of surviving a stroke.”
“Our new findings suggest that if brain cells run short of energy, they start to work more slowly,” says Chris Peers, professor at the University of Leeds. “However, it is better to work slowly than not at all. It is possible that this discovery could, in the long term, lead to new treatments for patients who have problems with circulation to the brain, placing them at higher risk of conditions such as stroke.
The research was funded by a grant from the Wellcome Trust.
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