Introducing the brain: The aging brain after 40 (Introduction)

by David Turell , Friday, September 30, 2022, 01:22 (783 days ago) @ David Turell

Current findings:

https://bigthink.com/neuropsych/great-brain-rewiring-after-age-40/?utm_source=mailchimp...

"The gathered evidence suggests that in the fifth decade of life (that is, after a person turns 40), the brain starts to undergo a radical “rewiring” that results in diverse networks becoming more integrated and connected over the ensuing decades, with accompanying effects on cognition.

***

"Early on, in our teenage and young adult years, the brain seems to have numerous, partitioned networks with high levels of inner connectivity, reflecting the ability for specialized processing to occur. That makes sense, as this is the time when we are learning how to play sports, speak languages, and develop talents. Around our mid-40s, however, that starts to change. Instead, the brain begins becoming less connected within those separate networks and more connected globally across networks. By the time we reach our 80s, the brain tends to be less regionally specialized and instead broadly connected and integrated.

***

“'Older adults tend to show less flexible thinking, such as forming new concepts and abstract thinking, lower response inhibition, as well as lower verbal and numeric reasoning,” the reviewers noted. “These executive function changes can be seen first in adults in their fifth decade of life, consistent with the findings of the systematic review that functional network connectivity changes reach their inflection point in the fourth and fifth decade.”

"But the news isn’t all bad for the aging brain. “Tasks relying on predominantly automatic or well-practiced processes are less impacted by age or may even increase slightly across the lifespan, such as vocabulary and general knowledge,” the authors wrote.

"So why do these brain networking changes even occur in the first place? The reviewers offered some learned speculation. They noted that the brain is a resource-hungry organ, ravenous for the simple sugar glucose. “The adult brain accounts for approximately 2% of total body weight but requires approximately 20% of total glucose supply,” they wrote.

"But as we get older, our bodies tend to slow down and the brain becomes less efficient. So not only is the brain getting less glucose, it’s also not putting the fuel to good use. Thus, the networking changes likely result from the brain reorganizing itself to function as well as it can with dwindling resources and aging “hardware.”

***

"The brain’s inner workings are mysterious indeed, but with this grand systematic review comprising hundreds of studies and tens of thousands of brain scans, we are at least starting to get a surface view of how it changes across our lifetimes."

Comment: perhaps all of these changes ae programmed into the DNA of brains neurons.