The brain is a plastic organ throughout life, neural networks adapting to use and experience. Many of the changes that occur with age are taking place in response to patterns of use, not just in response to damage and dysfunction. It isn't entirely straightforward to determine which is which. The research noted here doesn't give any particular insight into how to address undesirable changes in the aging brain, but does provide an interesting view into how the brain strives and succeeds to retain function in capacities that receive constant use.
The human cerebral cortex is only a few millimetres thick and arranged in numerous folds. This tissue usually becomes thinner with age. "This is a hallmark of aging. It is attributed, among other things, to the loss of neurons. As a result, some abilities deteriorate. In any case, it is generally assumed that less brain volume means reduced function. However, little is known about how exactly the cortex actually ages. That is why we examined the situation with high-resolution brain scans."
Researchers focused on the primary somatosensory cortex, a part of the cerebral cortex where signals from the tactile sense are processed. Using magnetic resonance imaging (MRI), the researchers were able to map this area of the cerebral cortex with unprecedented accuracy. "Until now, it had not been considered that the primary somatosensory cortex consists of a stack of several extremely thin layers of tissue, each with its own architecture and function. We have now found that these layers age differently. Although the cerebral cortex becomes thinner overall, some of its layers remain stable or, surprisingly, are even thicker with age. Presumably because they are particularly solicited and thus retain their functionality. We therefore see evidence for neuroplasticity, that is, adaptability, even in senior people."
Only the deeper layers of the cerebral cortex showed age-related degeneration: they were thinner in older study participants than in younger ones. "The middle and upper layers of the cortex are most directly exposed to external stimuli. They are permanently active because we have constant contact with our environment. The neural circuits in the lower layers are stimulated to a lesser extent, especially in later life. I therefore see our findings as an indication that the brain preserves what is used intensively. That is a feature of neuroplasticity."
Link: https://www.dzne.de/en/news/press-releases/press/the-cerebral-cortex-ages-less-than-thought
View the full article at FightAging
