Madrid, Spain – A recent pilot study conducted on the brains of marathon runners in Spain has revealed fascinating insights into how the human brain may adapt to extreme physical exertion by utilizing its own fatty tissue for energy. This groundbreaking research sheds light on a novel form of neuroplasticity that may help sustain brain function during prolonged periods of intense endurance.
The study, led by neuroscientists Pedro Ramos-Cabrer and Alberto Cabrera-Zubizarreta, found that during a marathon when glucose levels in the brain become critically low, certain neurons may begin to consume myelin – a fatty sheath surrounding nerve fibers in the brain. While myelin is traditionally recognized for its role in facilitating efficient neural communication, this study suggests that neurons can repurpose myelin as a source of fuel, particularly when conventional brain nutrients are scarce.
MRI scans of the brains of 10 marathon runners before and after a 42-kilometer race revealed significant changes in myelin markers within the brain’s white matter, where myelin is most concentrated. Interestingly, participants exhibited signs of myelin loss in brain regions associated with motor function, coordination, and sensory integration immediately after the marathon. However, these changes appeared to be reversible, with myelin markers rebounding within weeks post-run for most individuals.
The findings of this study present a unique perspective on myelin as a potential energy reservoir that the brain can tap into under challenging circumstances. This concept of metabolic myelin plasticity suggests that the brain may sacrifice small amounts of myelin in select regions to ensure overall brain function is maintained during periods of nutrient deprivation.
While the study’s sample size was limited, and the association with myelin was inferred indirectly, these results complement previous research on animal models, indicating that myelin can serve as a backup energy source when glucose is scarce in the brain. Understanding this metabolic mechanism could have implications for conditions related to myelin loss, such as multiple sclerosis, and provide insights into how the human brain adapts to extreme physical demands.
The evolutionary significance of myelin, particularly in relation to cognitive performance during strenuous activities like running, highlights the potential role of this fatty substance in human survival and success. Future research may delve further into the intricate interplay between myelin, metabolic adaptations, and brain function to unlock the full extent of the brain’s adaptive capabilities under duress.