Toothache is terrible!

The wish of each of us is "no tooth decay".

Because once the toothache comes up, you will experience the indescribable "deadly" pain.

At this point, you will find that when you take a breath, the pain will increase.

In dental clinics, dentists usually look for pain points by blowing cool air on the surface of the teeth to determine the location of tooth decay.

Then why is the feeling of toothache magnified under cold stimulation? Beijing time on March 27, published in the "Science Advances" in a new study, led by the University of Erlangen-Nuremberg, Germany, the Howard Hughes Medical Institute (HHMI) and Massachusetts General Hospital led the international After more than ten years, the research team finally clarified how the teeth perceive cold.

In mice and humans, odontoblasts contain cold-sensitive proteins that can detect temperature drops, and send signals to the brain to feed back severe pain.

Moreover, tooth nociceptors respond to cold much more than skin.

Researchers say that the development of specific drugs that target this receptor can help eliminate teeth's sensitivity to cold.

Odontoblasts (odontoblasts) are located around the pulp and connect with the pre-dentin.

Dentin is the hard tissue that constitutes the main body of the tooth, located in the inner layer of enamel and cementum.

When bacteria and acids erode the enamel on the tooth surface, the tooth suffers.

As tooth enamel is eroded, pits called tooth decay are formed.

About 2.
4 billion people worldwide (about one-third of the world's population) have untreated tooth decay in their permanent teeth, which can cause severe pain, including extreme sensitivity to cold.How do teeth perceive the cold? Previously, scientists proposed a major theory that the fluid in the teeth will flow with temperature changes, and the nerves will perceive the direction of this movement in a certain way, thereby signaling whether the teeth are cold or hot.

The study's co-corresponding author, HHMI's deputy director, neurobiologist David Clapham said: "We cannot rule out this theory, but there is no direct evidence.

" Fluid movement of teeth and tooth biology are usually difficult to study.

Scientists must cut through the hardest material in the human body—tooth enamel and dentin, all of which cannot destroy the soft pulp of the tooth and its internal blood vessels and nerves.

Otherwise, the entire tooth will be fragmented.

Therefore, the researchers did not intend to study the teeth.

Their work focuses on ion channels, which are pores in cell membranes that resemble molecular gates.

When a signal (such as chemical information or temperature change) is detected, the channel opens, allowing ions to flood into the cell.

This produces electrical impulses from one cell to another, which is a way to transmit information quickly and is essential for the brain, heart, and other tissues.

About 15 years ago, when Katharina Zimmermann, the head of the new study, was a postdoctoral fellow in Clapham's lab, the lab discovered that an ion channel called TRPC5 is highly sensitive to cold.

But they didn't know which part of the body the cold induction force of TRPC5 worked on, but they determined that it did not come from the skin.

In 2011, the team published the study in the Proceedings of the National Academy of Sciences (PNAS), showing that mice lacking ion channels can still perceive cold.

Odontoblasts containing the ion channel TRPC5 (green) tightly wrap the area between the pulp and dentin of mouse molars, Zimmermann said: "After that, our research seemed to have reached a dead end.

Until one day at lunch.
, We sat together to discuss this issue, and suddenly new ideas emerged. Professor Clapham said, what other tissues in our body can sense the cold? The answer is teeth.

"The study's co-corresponding author Jochen Lennerz, a pathologist at Massachusetts General Hospital, found after examining adult dental specimens that the TRPC5 channel is indeed present in the teeth, and more often in the teeth with cavities.

In this new study In, they confirmed this through mouse experiments.
TRPC5 does have the function of a cold sensor.
The
researchers did not knock out the tooth or examine its cells in a petri dish.
Instead, they developed a complete mouse jaw.
The system of bones, teeth, and mandibular nerves.

They recorded the nerve activity when the cold liquid touches the teeth.

In normal mice, this cold triggers nerve activity, indicating that the teeth feel cold; and in the absence of TRPC5
This is not the case in mice, or on teeth treated with a chemical that blocks ion channels.
This is the key clue that ion channels can sense cold, and TRPA1, another ion channel, seems to play a role.

Later, they tracked the TRPC5 channel and found a special cell type, namely odontoblasts.

So this also explains that when a dentin is exposed to a person while taking a bite of a popsicle, those TRPC5 cells will feel cold, and Send a sour signal to the brain.

Researchers say that this keen sense has not been studied as extensively as in other scientific fields.

Toothache may not be a fashionable research topic, but it is really important because it affects many people.

Zimmermann pointed out that this discovery lasted more than ten years.
It
is very difficult to figure out the functions of specific molecules and cells, she said.

"Good things take a long time, and good research may take a long time.

"In addition, Zimmermann also explained how an ancient traditional treatment relieves toothache.

She said: "Clove oil can be used to relieve pain during acute tooth inflammation, because its main component contains a chemical substance that can prevent the production
of'cold sensor' protein.
Moreover, clove oil has been used in the field of dental treatment.
For centuries.

"Link to the paper: https://advances.
sciencemag.
org/content/7/13/eabf5567 Related reading: Toothache is really a disease! Because it can cause inflammation storms, leading to a series of terrible health consequences, brush your teeth, prevent cancer! Gut: Periodontal disease increases the risk of cancer! Hot Article Selections of 2020 1.
The cup is ready! A full paper cup of hot coffee, full of plastic particles.
.
.
2.
Scientists from the United States, Britain and Australia “Natural Medicine” further prove that the new coronavirus is a natural evolution product, or has two origins.
.
.
3.
NEJM: Intermittent fasting is right The impact of health, aging and disease 4.
Heal insomnia within one year! The study found that: to improve sleep, you may only need a heavy blanket.
5.
New Harvard study: Only 12 minutes of vigorous exercise can bring huge metabolic benefits to health.
6.
The first human intervention experiment: in nature.
"Feeling and rolling" for 28 days is enough to improve immunity.
7.
Junk food is "real rubbish"! It takes away telomere length and makes people grow old faster! 8.
Cell puzzle: you can really die if you don't sleep! But the lethal changes do not occur in the brain, but in the intestines.
.
.
9.
The super large-scale study of "Nature Communications": The level of iron in the blood is the key to health and aging! 10.
Unbelievable! Scientists reversed the "permanent" brain damage in animals overnight, and restored the old brain to a young state.
.
.