The human brain has long been considered an organ with limited capacity for regeneration. But what if we could rekindle its ability to produce neurogenesis (new neurons) even in old age? A groundbreaking study by researchers at Stanford Medicine suggests that this is possible. By manipulating the genes responsible for glucose transport, scientists were able to reawaken dormant neural stem cells in the brains of elderly mice.
The discovery, which confirms and extends the results of previous studies, could represent a breakthrough in our understanding of neurogenesis and open new avenues for the treatment of age-related neurological disorders.
The Dynamic Brain: An Ever-Evolving Universe
Think of your brain as a city in constant evolution. There are old and stable neighborhoods, but also areas in constant ferment. Thehippocampus and the olfactory bulb they are like the historical centers of this neural “metropolis”, where turnover is the order of the day.
Tyson Ruetz, the brilliant scientist behind this study (that I link to you here), explains that in these areas, neurons have a shorter lifespan than expected. It's as if there were a construction site where old structures are continually replaced by new, brand-new structures. But what happens when this process slows down with age? Here's the part that gives me goosebumps.
The Glucose Conundrum: When Less Is More
Ruetz and his team found that by turning off the genes responsible for glucose transport, neural stem cells awaken from their slumber. It's as if they've found the switch for brain youth.
Just think: in old mice, this manipulation led to an increase of more than doubling the newborn neurons. An epic undertaking, with its own epic narrative. These little cellular heroes embark on a real journey: they are born in the subventricular zone (the brain's nursery) and then migrate to the olfactory bulb, where they begin their new life.
A mass migration through the brain, with new neurons making their way to their final destination. And when they arrive, they integrate seamlessly, forming new connections.
Beyond Smell: Implications for Brain Injury and Stroke
But it doesn’t stop there. This discovery could have implications far beyond our sense of smell. Ruetz suggests that the same mechanism could be used to repair brain damage caused by stroke or trauma.
Think of the possibilities: We may one day be able to “order” our brains to activate neurogenesis and repair themselves after damage, with the help of an army of tiny workers ready to rebuild the damaged parts.
Diet and “eyelashes”: the links with neurogenesis
Anne Brunet, another mind behind this study, suggests that a diet low carb may have similar effects on neurogenesis.
As if that were not enough, researchers have discovered another actor in this cellular comedy: the primary eyelashes. These tiny cellular antennas appear to play a crucial role in waking up neural stem cells. It’s as if we’ve discovered that our brain cells have little antennas that pick up “wake up” signals.
We are at the early stages of a discipline that will become fundamental over time. In the future, I feel, there will be doctors specialized in cellular communication who are able to receive and interpret the information exchanged between cells (such as those that regulate neurogenesis), and translate them into therapeutic approaches.
The Future of Neurogenesis: What Lies Ahead?
We are just at the beginning of this exciting journey. The next step, Brunet tells us, is to study the effects of glucose restriction on neurogenesis in larger animals and then in humans.
We may be on the cusp of discoveries that will radically change the way we think about brain aging. Imagine a future where we can keep our brains young and plastic well beyond current limits, where Alzheimer's and other neurodegenerative diseases can to be held back or even reversed.
So, the next time someone tells you that “you can’t teach an old dog new tricks,” smile. Because science is showing us that when it comes to the brain, learning and growth are ageless.