Protein plaques in the brain may be caused by failing mitochondria Sebastian Kaulitzki/Alamy
IF YOU own a car, you will have noticed the engine getting less efficient with time. The further you drive it, the more fuel it takes to make the same journey – until, eventually, it becomes so underpowered that it needs a physical push to climb even a gentle hill.
Now, it is emerging that much the same is true of the human brain. Microscopic structures called mitochondria, found in every brain cell, are quite literally the engines of our thoughts and feelings. As we age, they find it harder and harder to produce sufficient energy to power our mental activities. Worse, in a similar way to an old car leaving clouds of smoke in its wake, the cell’s powerhouses start generating unwanted waste products that slowly poison our brains. This means that malfunctioning mitochondria may underlie many of the most devastating brain conditions, including Alzheimer’s, Parkinson’s, Huntington’s and motor neuron disease.
According to this “grand unified theory” of neurodegeneration, we could prolong our brain’s healthy functioning by recharging our neurons through restoration of their powerhouses. The idea is already inspiring some exciting new therapies for age-related brain conditions, with multiple drug candidates under investigation. Some researchers are even exploring the possibility of transplanting healthy mitochondria into damaged, ageing brains to re-energise them. “If you keep changing the parts of a car, it can last forever,” says Claudio Soto, a neurologist at the University of Texas Health Science Center at Houston. “So what happens if we try to do the …
