When our phones and computers run out of power, their glowing screens go dark and they die a sort of digital death. But switch them to low-power mode to conserve energy, and they cut expendable operations to keep basic processes humming along until their batteries can be recharged.
Our energy-intensive brain needs to keep its lights on too. Brain cells depend primarily on steady deliveries of the sugar glucose, which they convert to adenosine triphosphate (ATP) to fuel their information processing. When we're a little hungry, our brain usually doesn't change its energy consumption much. But given that humans and other animals have historically faced the threat of long periods of starvation, sometimes seasonally, scientists have wondered whether brains might have their own kind of low-power mode for emergencies.
Now, in a paper published in Neuron in January, neuroscientists in Nathalie Rochefort's lab at the University of Edinburgh have revealed an energy-saving strategy in the visual systems of mice. They found that when mice were deprived of sufficient food for weeks at a time — long enough for them to lose 15%-20% of their typical healthy weight — neurons in the visual cortex reduced the amount of ATP used at their synapses by a sizable 29%.
But the new mode of processing came with a cost to perception: It impaired how the mice saw details of the world. Because the neurons in low-power mode processed visual signals less precisely, the food-restricted mice performed worse on a challenging visual task.
"What you're getting in this low-power mode is more of a low-resolution image of the world," said Zahid Padamsey, the first author of the new study.
[...] A significant implication of the new findings is that much of what we know about how brains and neurons work may have been learned from brains that researchers unwittingly put into low-power mode. It is extremely common to restrict the amount of food available to mice and other experimental animals for weeks before and during neuroscience studies to motivate them to perform tasks in return for a food reward. (Otherwise, animals would often rather just sit around.)
[...] "We have to think really carefully about how we design experiments and how we interpret experiments if we want to ask questions about the sensitivity of an animal's perception, or the sensitivity of neurons," Glickfeld said.
Journal Reference:
Zahid Padamsey et al., Neocortex saves energy by reducing coding precision during food scarcity [open], Neuron, 2022. DOI: 10.1016/j.neuron.2021.10.024
(Score: 0) by Anonymous Coward on Saturday June 25 2022, @05:42AM
There are other brain mode?
(Score: 2) by darkfeline on Saturday June 25 2022, @05:57AM (3 children)
It's not really a distinct mode is it? When you're sleep deprived or sick or in a low oxygen environment, your brain also goes into "low-power mode".
"Give thing less energy, thing go slower"
Study is nice, obvious conclusion is obvious, quick, make up a marketable title.
Join the SDF Public Access UNIX System today!
(Score: 0) by Anonymous Coward on Saturday June 25 2022, @07:06AM
Now now, just admit it. You are just mad you'll be fed skinny mice, darkfeline.
(Score: 2) by FatPhil on Saturday June 25 2022, @09:56AM (1 child)
I don't have time to expand on this point, as I'm busy working on my new paper: /Green jelly-babies fall downwards when dropped/.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 3, Insightful) by Anonymous Coward on Saturday June 25 2022, @07:55PM
If academics didn't test things that seemed obvious, we'd probably still be bleeding people to remove the humors from the body to cure illness.
(Score: 4, Touché) by Rosco P. Coltrane on Saturday June 25 2022, @08:17AM (3 children)
I posit that an excess of calories also makes the brain foggy. Just look at America.
(Score: 1, Troll) by Anonymous Coward on Saturday June 25 2022, @09:59AM
(Score: 0) by Anonymous Coward on Saturday June 25 2022, @05:17PM
Indulging in one of the deadly sins is a good indicator that you are probably indulging in others.
(Score: 0) by Anonymous Coward on Sunday June 26 2022, @04:42PM
>> I posit that an excess of calories also makes the brain foggy. Just look at America.
But Biden's not fat, so his brain fog must come from extreme old age.
(Score: 0) by Anonymous Coward on Saturday June 25 2022, @05:48PM (1 child)
(Score: 0) by Anonymous Coward on Sunday June 26 2022, @02:10AM
Z's indeed. Interesting experiment that backs up the obvious.
In the short term, if you don't feed your brain, it don't work so good.
In the long term, if you over feed, you risk the same outcome. (Clogged everything?)
O2 is useful. (Partial pressures need to put O2 into the blood and what they feed.)
Reasonable temperature. (Excessive hot or cold cause slow/shutdown to just survive.)
Hydration and electrolite balance as well. (And it takes a few days to fully recover so stay ahead of this.)
Then fuel, as in sugar and carbs that convert to same. (A snack every hour...)
Seems like it should be easy to do an congnitive ability under these stresses for humans. So, if your have been paying attention to how yur work, why is about this other than ZZZZZZZZZZZZZZZZ