Hungry for a long time, the brain will enter the "power saving mode"! Your senses are weakened and you can't see clearly

Yang Jing From the Aofei temple
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Have you ever thought about it , The brain is actually like a cell phone 、 It's like a computer , Also have Energy saving mode .

The latest discovery of scientists , Mice on a long diet , Its brain will enter this mode , As a result, the accuracy of visual perception will become lower .

In other words , In this state , Mice see the whole world in low resolution .

Lai Kangkang, what kind of research is this .

How the brain saves energy

Although the brain only takes up less than the body mass 2%, But it took about 20% Total calorie intake of the human body , Among them, the cortical network occupies 50% Energy consumption .

But just as mobile phones and computers will switch to low-power mode when there is no power , To keep the basic task flow running properly .

As an analogy , Will the human brain also have its energy-saving strategy ？

In this context , Neuroscientists from the University of Edinburgh , Start with the mouse's visual system .

First , Set up the environment . The researchers restricted the mice 'food intake for three weeks , Let them lose weight 15%-20%.

Special note ： Not hungry .

next , Assess neuronal activity and ATP Consumption of .

Our brain cells , It mainly depends on the stable transport of glucose , Turn them into adenosine triphosphate （ATP）, Promote their information processing .

The researchers examined the primary visual cortex of mice V1 Information coding and energy consumption .

Specific methods , They designed one with two “ exit ” Underwater chamber , Each exit is marked with black and white strips at different angles .

Where vertical （90 degree ）  Image is true exit , The mouse can leave the water through this mouth .

After several training sessions , The mouse learned to associate the exit with a vertical angle pattern .

To the real experimental stage , Researchers used whole cell patch clamp and two-photon imaging to record and evaluate .

Results found , When there is a large difference between the correct image and the wrong image , Mice can easily find the platform .

But when the angle of the picture is less than 10 When , Dieting mice can no longer distinguish them as accurately as full mice .

To neural activity , The researchers measured the number of voltage spikes inside neurons , The electrical signals that neurons use to communicate .

The results showed that the peak rate of diet mice was similar to that of control group , But synapses ATP The use of , Proportion up to 29%.

In addition, they found two changes in neurons , One is that neurons increase input resistance , This reduces the current at the synapse ; Second, depolarization of resting membrane potential , Thus, the excitability of neurons is preserved .

In mice, however, the diet returned to normal , After the weight has returned to its original level , Its visual perception ability is also restored .

The researchers believe that , The decrease of neuron coding accuracy and food restriction , Fat volume regulating hormone —— Leptin A decrease in the level of

There have been similar studies before

in fact , As early as 2016 There has been relevant research since ： Short term starvation changes the way neurons process information .

at that time , Neuroscientists from the University of Michigan found that , When hungry mice saw pictures of food , Neurons become very active .

But as long as they have enough to eat , This neuronal activity is reduced .

In the study of human imaging , The same thing happened .

And earlier , Some researchers also realize that , After a few hours of starvation , The brain selectively conserves energy .

Which process consumes the most energy , Just close the one .

2013 year , French scientists found in the brains of flies , They shut down brain pathways that form long-term memories .

If this path is forced to activate , Hungry flies die faster .

But is there a similar behavior in the more advanced brain , It's not known yet .

As for this paper , This is the first study of long-term dieting , How the brain adapts to save energy .

Interested friends , You can find out more about the paper below ～

Thesis link ：
https://www.cell.com/neuron/fulltext/S0896-6273(21)00839-4

Reference link ：
https://www.quantamagazine.org/the-brain-has-a-low-power-mode-that-blunts-our-senses-20220614/