Measuring brain aging
Wrinkles reveal how aging has degraded your skin, but how can you tell how well your brain is coping? Measure levels of lactic acid, perhaps. It seems that a buildup of the chemical in the brain is a hallmark of the aging process, in mice at least.
The finding came when Jaime Ross from the Karolinska Institute in Stockholm, Sweden, and colleagues investigated how aging is affected by damage to the DNA in mouse mitochondria, the energy-producing part of cells.
The team modified mitochondrial DNA, producing a mouse strain that aged prematurely. In these mice and healthy controls, the time it took for levels of lactic acid in the brain to double correlated with how fast they aged.
Lactic acid is a normal product of metabolism, so Ross' team speculated that age-damaged mitochondria could be affecting metabolic processes. Indeed, the brains of both types of mice showed damage to the genes responsible for lactate regulation (Proceedings of the National Academy of Sciences).
Future studies may reveal if changes in brain lactate are linked to neurodegenerative disease in humans, says Ross.