where does pain come from?

Why Do We Feel Pain? How does It Work?

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Imagine a life without pain. No aching joints. No stinging sunburns. No throbbing headaches.  Think again if you think that sounds great.

Some individuals can’t sense pain. They are born that way. They also tend to die young- unlike, say, people who cannot hear or see.

Pain protects us. You recoil in pain when you touch a hot stove. That sensation will help you avoid getting a burn that could be risky — even deadly. A foot’s throbbing instructs you to stay off it until it heals, so you don’t do more harm. Without those signs, we would all be in trouble. Big trouble!

Some pain is simple. Burn your skin, pull on a muscle or break a bone, and you feel distressed. This effect is known as pain.

Other pains may last for months or even years. Known as chronic pain, its origin remains a mystery. In actuality, “sometimes the neurotic system can get it mistaken,” says Steve Prescott. “You have pain which shouldn’t be there,” explains this pain researcher at the University of Toronto, Canada, as well as the local Hospital for Sick Children.

Scientists are still working out different causes of pain and the treatment for every type. Pain’s biology is complicated. But the great news: Researchers are learning more about it continuously.

chronic knee pain

Signal Sent

Pain is a sort of perception, like smelling, hearing, and tasting. Those sensations tell you what’s happening in the world around you. Pain tells you what is happening within your body’s world.

When you met with an accident, your brain is responsible for delivering the news. Imagine that your ankle twists. Nerve cells in your ankle pick the signal that something is wrong. A network of nerve cells carries this information to the spinal cord. From that point, it shoots up into the mind. The brain then translates the word and registers the feeling: Ow!

That’s the easy explanation. There is still a lot of questions about how those messages travel and how the brain turns them into a “feeling.” Piece by piece, scientists are beginning to understand the working of this complex system.

In the last few years, scientists found receptors for various sorts of pain. A receptor is a specific protein on a cell. Its task is to collect signals coming at the edge of the cell. A receptor known as TrpV1, by way of instance, is located on nerve cells.

TrpV1 identifies signals of debilitating heat. It does that in a few ways. For beginners, the receptor appears to respond to heat itself. That is not totally unexpected as warmth also changes the form of certain substances in the body.

TrpV1 can detect those modified compounds. TrpV1 snaps into action when you touch a hot stove. It gets the too-hot-to-handle message and transmits it to the mind. Interestingly, that corresponding receptor also finds the chemical compounds that make hot chili peppers taste so painfully hot.

Signal Received

The search for receptors has become a popular area for scientists, says Prescott. But he notes, research has not answered the critical question of how those messages are converted into what you really believe when you experience pain.

Answering that question can help a lot of people. In some instances, doctors know the cause of pain. Inflammation is a common one. Inflammation is one means the body responds to injury. Beyond pain, it causes warmth, redness, and swelling. Arthritis, as an instance, is a disease that causes inflammation in the joints. The nerves represent another cause of pain. Diabetes is a condition that can destroy the nerves in the feet and hands. That damage contributes to numbness, tingling, and pain. Drugs used in the treatment of cancer can also cause severe nerve damage.

Many other pain disorders have no explanation. Take migraines. These headaches are not caused by injury or inflammation. They are not connected to nerve injury, either.

For a long time, experts considered migraines and other episodes of chronic pain as symptoms of another issue, says Theodore Price. He’s a pain researcher at the University of Texas in Dallas. More lately, pain researchers have changed their way of thinking. Price says scientists think that pain occurs when the nervous system itself gets damaged.

Pain Memories

Brain cells are amazingly flexible. If you discover something new or make memories, your brain cells actually change the pattern. “When you learn a math equation, the structure of your brain is changing,” Price says.

It turns out that the exact systems involved in memory and learning are also involved in sensing pain. To put it differently, pain alters nerve cells. Those changes happen both in the spinal cord and in the brain. And they can last even after the primary trigger for pain disappears. Price calls this a sort of “pain memory.”

He and other scientists are attempting to work out if they can reverse those changes. If they can wipe out the “pain memory” stamped on the cells, then perhaps they can cure chronic pain. They have analyzed some medications that interfere with molecules which transmit messages to accomplish this. (Molecules are the smallest components of chemical compounds which take part in chemical reactions.) The drugs are newly designed compounds which haven’t been tested yet in humans. They did appear to erase pain memory in rats and mice in the experiments of Price.

But there persists a problem. Messing with brain cells may have unintended side effects. “You don’t need to wipe out people’s memories or alter who they are,” Price explains. Before he and his associates can test their approach in people, a lot of work will be necessary to make sure it’s safe.

In Toronto, Prescott is currently working to understand what might go wrong with the system to unleash chronic pain. Part of the research involves figuring out pain messages travel through the body.

Some scientists have indicated there are networks for pain. This type of “circuit” of neural cells would have just 1 task: transmit ouch signals.

Other experts think the Pain only the same circuits that communicate messages about non-painful feelings. If this theory is right, the network of cells which tells you a cat’s fur feels tender also might say to you a scrape from its claws really hurts.

Prescott considers the second theory is the right one. One clue that it is right comes from an old illusion, known as the thermal grill.

Just as optical illusions trick the eye, neural illusions can trick the body into sensing imaginary pain. The thermal grill is formed of metal bars put to different temperatures. The bars alternate: cold, warm, cold, warm. It is going to feel warm or cold if you touch a single bar. But put your hand over the entire grill at once, and it will sense painfully hot. This manner, Prescott says, “You can fool the nervous system into believing the pain.”

That’s a notion that the same network that picks up sensations, including cold and warm senses pain. Prescott thinks pain may occur when the system becomes confused as it does from the hot grill method. “There may be similarities between the thermal grill and how the nervous system becomes damaged to cause pain,” he explains.

Then again, a confused, nervous system might be one explanation. “Pain is a very complex phenomenon,” says Diatchenko. “It may be broken in several distinct ways.”

fallen down feeling painExtra sensitive

Pain is complicated for many reasons. There are unique kinds of pain — there is a muscle ache different from a burn or a pinch. Also, some individuals are more susceptible to pain than others.

Diatchenko at McGill University is attempting to understand these differences. She’s currently searching for genes that manage pain sensation. A gene is a part of DNA that retains or codes instructions, for producing a protein. Genes are inherited by offspring from their parents. Genes affect how an organism behaves and appears.

Diatchenko has taken people into her lab and directed them to touch a hot surface. She raises the heat, asking them to state when the heat gets painful. The range is enormous, ” she says. “Some people are, and some people are actually not.”

Sensitive people aren’t just nervous or wimpy. Regions of the brain involved in pain become active earlier in such folks. That is what brain scans using fMRI or functional magnetic resonance imaging. (fMRI uses powerful magnetic fields to make pictures of brain areas while they’re active.) Some individuals, in other words, actually feel the pain. They literally cannot take the heat.

Many distinct genes are included in sensing pain. Scientists have recognized some that appear to be necessary. One is a gene known as COMT.

Different forms of the gene occur. Naturally, Diatchenko recognizes. Some people have a very active kind. They have a higher threshold for pain. In other individuals, the gene is less intense. These people sense pain more eagerly. Interestingly, the gene isn’t involved in pain. Differences in COMT have been associated with differences in planning, emotions, memory and even character.

There are superior reasons why understanding a person’s sensitivity to pain is essential, Diatchenko says. Individuals who are sensitive to pain are more likely to develop a chronic pain illness. Learning about what makes their method for pain more might help researchers find new ways to deal with pain.

That is the target for nearly every scientist who studies pain biology. Since these specialists fill in the blanks, they’re optimistic that their study will help the millions of individuals who experience unexplained pain.

It might look like there is still a lot to learn. That is because the job has only started. Since the early 2000s have scientists began to understand the pain in the level of molecules and cells, Price says. “We are still in early days” of pain study, he notes. “The next 15 years? Who knows what it will bring.”

Power Words

Acute: A conditions, like illnesses (or its symptoms (including pain), that’s typically short in duration but severe.

Arthritis: A disease that produces painful inflammation in the joints.

Brain Scan: Using imaging technology, typically using X rays or a magnetic resonance imaging (or MRI) machines, to see structures in the brain. With MRI technologies — especially the kind called operational MRI (or fMRI) — the action of different brain areas can be considered during an event, like viewing pictures, calculating amounts or listening to music.

Chronic: A condition, like a disorder (or its signs (such as pain), that continues for quite an extended time.

Circuit: A network of that transmits electrical signals. In the body, nerve cells to create circuits which relay messages to the mind. In electronic equipment, wires route those signals to trigger some computational, mechanical or another purpose.

Compound: A compound is a matter made from two or more chemical elements. By way of instance, water is a compound made of two hydrogen atoms and one oxygen atom.

COMT: A gene that is included in sensing pain. It’s been associated with differences in personality, planning, memory, and emotions.

Diabetes: A ailment in which the body either makes too little of the hormone insulin (called type 1 conditions) or ignores the existence of too much insulin (called type 2 diabetes).

Functional MRI (or fMRI) a sort of medical imaging that employs powerful magnetic fields to make representations of brains while they’re active.

Gene A section of DNA that codes, or holds directions for producing a protein. Genes are obtained by offspring from their parents. Genes affect an organism behaves and appears.

Inflammation: Your body’s response to cellular injury. It involves heat, redness, swelling, and pain.

Migraine: An extreme headache which is usually followed by vision and nausea changes.

Molecule: An electrically inactive set of atoms that represent the smallest amount of a chemical compound. Molecules can be formed of different kinds or the same kinds of particles. By way of instance, the oxygen from the atmosphere consists of two oxygen molecules (O2), but water contains two hydrogen atoms and one oxygen atom (H2O).

TrpV1: A kind of pain receptor on cells which detects signals about debilitating heat.

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