
Sedentary Behavior May Thin Memory-Related Brain Area - ryan_j_naughton
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0195549
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prostoalex
Sedentary behavior inhibits quality sleep, which has been shown to impact
memory.

I wonder if researchers tracked the quantity and quality of sleep (REM vs
NREM) among study participants. From the graphs it doesn't look like they did.

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cavanasm
From the abstract, it looks like they just gave the participants a survey, and
did an MRI. Actual time spent with the participants probably wasn't more than
a few hours for just that (probably for cost reasons too).

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btbuildem
Perhaps a sedentary person makes fewer notable memories (their surroundings
don't change much), and the respective area of the brain atrophies?

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gldev3
" No significant correlations were observed between physical activity levels
and MTL thickness. Though preliminary, our results suggest that more sedentary
non-demented individuals have less MTL thickness. "

So, this wasn't conclusive? Just in case i may walk my dog twice as much but
not much can be done with a software engineering job and sedentary hobbies.

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truculation
Somewhat crazy idea but anyone know if sedentary behaviour or poor memory are
associated with graying hair at the temples?

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CoryG89
Interesting that you bring this up. I don't know the answer, but I'll be 29
this year and have just recently started getting some gray hairs. The most
prominent are two gray patches right over my temples.

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truculation
Yes, it may be just a coincidence that this is so, with the temples and the
temporal lobes being physically close to one another. But intuition makes me
wonder.

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moate
Biologically, this doesn't make sense. One of the more accepted causes of
graying-1 is a build of of H202 in the hair follicle resulting in the hair not
holding as much melanin. It seems unlikely that this would come from the
brain, through the skull since that's not how the circulatory system gets
in/out of the brain (it mostly goes through the neck/spine).

1:
[https://www.nytimes.com/2009/03/10/health/10well.html](https://www.nytimes.com/2009/03/10/health/10well.html)

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truculation
Indeed, but if control and resources (e.g. immune resources) are allocated via
some kind of map in the brain then mightn't that make proximity relevant?
(notwithstanding the bone barrier!) I admit it's a stretch...

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moate
Again, not really how things work. You're assuming that the dermal layers
closest to a section of the brain are somehow working with that section of the
brain and that's not really how it works. The circulatory system (which is
most likely what's responsible other than the skin/dermis itself) doesn't
route from brain to skin that way (because of the bone).

There is a pretty large concentration of veins/arteries - 1 that come up
around the temple, so that could be related to the frequency of graying
starting there.

1- [https://www.gettyimages.com/detail/news-photo/superficial-
ar...](https://www.gettyimages.com/detail/news-photo/superficial-arteries-and-
veins-of-the-face-and-scalp-news-photo/143063936#superficial-arteries-and-
veins-of-the-face-and-scalp-picture-id143063936)

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cheschire
"Indeed, one can be highly active yet still be sedentary for most of the day.
"

That's a hugely interesting note there in the introduction.

