hikes or fans of TV series and films Star Trek We know very well one of the most repeated phrases in all of them: “Space, the last frontier…”. But before we delve into the mysteries of space, we have to explore many other boundaries within ourselves, such as the central nervous system. A system about which important myths have recently been debunked, including those related to the formation of new neurons and new neural connections.
Neurons die if left isolated
There has been debate for many years about whether new neurons can be formed in the mature brain or whether this ability disappears after the first years of development. It is clear that during embryonic development, additional neurons are formed, and many of them die in this process because they cannot establish adequate relationships with other neurons or other cells. After all, communication between neurons is essential for their survival; if they remain isolated, they will die.
Another key aspect is that neurons are very sensitive to change. This is why they die from severe injuries or inflammation associated with trauma, autoimmune diseases or infections. On the other hand, they are also very sensitive to deficiencies in the use of cellular energy. Consequently, degenerative diseases such as Parkinson’s disease or mitochondrial diseases cause neuronal death.
Given all this, the possibility that we may one day be able to regenerate neurons lost due to injury or infection, as well as restore lost functions due to mitochondrial degeneration, would represent a huge clinical improvement for millions of people.
Brain stem cells exist, but they cannot regenerate the entire brain
Although we are not entirely sure that there is clear neurogenesis in the adult human, certain “niches” have recently been discovered that appear to house cells capable of becoming mature neurons. However, these niches appear to be located in very specific areas of the brain, so their ability to regenerate the entire brain is nil. And, as happens in other stem cell niches, regenerative capacity declines with age, although in some people at a slower rate than others.
Read more: Super Elders with Super Neurons: Why is there a brain that defies the flow of time?
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Another thing is neuroplasticity, that is, the ability to establish new connections between neurons. This ability is regulated by physiological factors such as pregnancy, during which neuroplasticity is accelerated.
It is not surprising, for example, that nutrition influences neuroplasticity even early in life or even during embryonic development. Various studies have shown that consuming ultra-processed and highly digestible foods negatively impacts neuroplasticity, while consuming unprocessed foods, especially vegetables rich in polyphenols, helps increase the ability of neurons to maintain and establish new interactions.
It is therefore not at all surprising that numerous studies have shown a relationship between the quality of the gut microbiota, associated with the quality of nutrients, and the ability of neurons to maintain and establish new connections. In this regard, the profile of chronic inflammation associated with neurodegeneration establishes a clear link between unbalanced nutrition and loss of neuronal capacity.
Avoid losing connections between neurons at all costs.
We now know that the generation of new neurons in adults is limited and declines with age. Therefore, mechanisms to maintain neuronal function for as long as possible should be the target of therapies aimed at preventing the more than certain pandemic of neurodegenerative diseases associated with the increasing number of elderly people.
Read more: The pandemic has put aging in the spotlight
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It is becoming increasingly clear that age-related cognitive decline or Alzheimer’s disease is multifactorial and that loss of communication between neurons is key to their death and disappearance. Therefore, maintaining connections or synapses between neurons preserves their functionality and therefore blocks or slows down the progress of neurodegeneration.
In this entire process, it is not only the accumulation of misfolded proteins both outside and inside cells that plays an important role. Also important is the activity of glial cells, which support neuronal activity, metabolism and waste elimination, while controlling inflammation.
Thus, different types of glial cells—astrocytes, oligodendrocytes, and microglia—are gaining increasing roles in neuronal maintenance, neuroplasticity, and perhaps also in neuronal regeneration in the few niches where this capacity is retained in adults. One of these stellar roles of glia in neuronal degeneration involves the inflammatory or neuroinflammatory process, which is of increasing importance.
Although there is great interest in promoting neuronal regeneration to prevent neuronal diseases associated with aging, preventing neuronal damage should be more important. And for this, science has already shown that nutrition, blood antioxidant levels, lifestyle, physical activity, social activity, and reducing chronic inflammation and the factors that influence it are very effective treatments.
Juvenal already said this in his Satire.Orandum est ut sit mens sana in corpore sana” almost anticipating, without even knowing what a neuron is, that maintaining cognitive abilities largely depends on proper nutrition, physical and social activity and a healthy lifestyle.