Fear is a survival technique created by evolution. But there are a small number of people suffering from a rare inconvenience that prevents them from being afraid
Imagine how it would be to jump from a plane and don’t hear anything. No adrenaline discharge, no change in your heartbeat.
This is the reality for British Jordy Cernik. He removed his adrenal glands to reduce anxiety caused by cushing syndrome, a rare disease that occurs when the adrenal glands produce very cortisol, stress hormone.
But the treatment worked too well. Cernik stopped trying anxiety, but there was something wrong.
In 2012, during a trip to Disneyland in the United States, he realized that he was not afraid of the Russian mountains.
He jumped from a plane in the skies, walked in a zip line in Newcastle, in the United Kingdom, and hit the Shard building in London. And he didn’t feel the slightest change in the wrist.
Cernik’s experience is rare, but it is not the only one. This sensation may seem familiar to people who suffer from Urban-Wiethe’s disease, also known as lipoidoproteinosis, as a rare genetic condition that has been diagnosed only in about 400 people to date.
A famous urban patient, known as MS, has been the subject of scientific studies at the University of Iowa in the United States since the mid -1980s.
At the beginning of the 2000s, a university student joined the research team and started looking for ways to scare his name was Justin Feinstein.
Today it is a clinical neuropsychologist at the Float Research Collective, which promotes reduced environmental stimulus therapy (rest) as a treatment for pain, stress, anxiety and related conditions.

“We show you all the horror films we can find,” recalls Feinstein.
But neither The Blair witch (1999), Arachnophobia (1990), Illuminated (1980) e The silence of the innocents (1991) They aroused any type of fear in SM not even a visit to the Waverly Hills Sanatorio, a frightening house infested in Louisville, in Kentucky, had some effects.
“We exposed it to threats of real life as snakes and spiders,” says Feinstein.
“Not only did he show a pronounced absence of fear, but he could not stop approaching them. He had this almost irresistible curiosity to want to touch and interact with the different creatures.”
Urban disease is caused by an isolated mutation in the ECM1 gene on chromosome 1.
ECM1 is one of the many fundamental proteins for maintaining the extracellular matrix (ECM), a support network that maintains cells and tissues in progress.
When ECM1 is damaged, football and collagen accumulate, causing cell death.
A part of the body that seems to be particularly vulnerable to this process is cerebelous amygdala, a region of the almond -shaped brain. It was believed for a long time that he participates in the elaboration of fear.
Difficulty perceiving threats
In the case of MS, he stopped being afraid when Urban-Wiethe’s disease destroyed his amygdala.
“The impressive is that [o efeito] It is specific to fear “, explains Feinstein”. Your ability to elaborate other types of emotions, mostly remains intact, both joy, anger or sadness. “
But this story, in fact, is more complicated than it seems. Ambdala can play a more important role in some types of fear than in others.
It seems to be fundamental, for example, for the Conditioning to fear.
Road experiments show that animals suffering from electric shocks immediately after a noise learn to be frozen when they hear the noise in insulation.
But while SM knows that it should not touch a hot pan that has just come out of the oven, it cannot be conditioned to fear. That is, it is not accelerated by heartfish or adrenaline when the stimuli previously associated with pain were presented.
SM also is not able to recognize the facial expressions of the fear of others, although it can detect expressions of joy and sadness.
It is also extremely sociable, but in parallel, it has difficulty recognizing and avoiding dangerous situations. This led her to suffer threats with a knife and a firearm on more than one occasion.

“He often approaches people who should avoid and have faced many problems because of his inability to feel the reliability of individuals,” said Feinstein.
In a study, the researchers asked a stranger to approach SM, who reported the distance he felt most at ease.
Its favorite distance was 34 cm, almost half of the other volunteers. This indicates that it is rare with people in his personal space.
“In that situation, SM and other people with tons injuries will face face to face with relatively unknown people, something that checks healthy with intact tonsils would never do,” explains the professor of psychology Alexander Shackman of the University of Maryland, in the United States.
The discovery indicates that the amygdala can participate in the organization of how we react to the social world.
Different types of fear
But there are some types of fear that seem to happen independently of the amygdala.
In an experiment, Feinstein and his colleagues asked to inspire carbon dioxide, which triggers a sense of fear and suffocation in some people.
The scientists hoped that he would react without fear, but with his surprise, she panicked.
Two other patients with amigdala injuries have also undergone an intense fear during the experiment.
“In the case of MS, which caused a complete panic attack,” says Feinstein. “It was the most intense fear he tried throughout his adult life.”
The discovery led Feinstein to dedicate a decade to the search for truth about the amigdala function in relation to fear. The result is that in reality there are two different paths for fear in the brain, depending on whether the threat is external or internal.

When the question are external threats, the amygdala acts as the director of an orchestra. He directs the other parts of the brain and the body to generate a reaction.
First of all, he receives information from the brain areas that elaborate vision, smell, taste and hearing. If the amygdala detects a threat, such as the approach of a thief, a snake or a bear, send messages to the hypothalamus, a region just above the back of the neck.
The hypothalamus therefore communicates with the pituitary gland, which in turn causes the adrenal glands to release cortisol and adrenaline in the bloodstream.
“This will cause an increase in heartbeat and blood pressure, evoking all types of classic combat or escape symptoms, a typical fear reaction,” explains Feinstein.
But when it comes to internal threats, how to detect the increase in CO₂ levels in the blood, the brain manages everything differently. The body interprets the high level of CO₂ as a sign of imminent suffocation, since there are no oxygen sensors in the brain.
TO research De Feinstein has shown that the brain trunk, a region that regulates the functions of the unconscious body, such as breathing, is the one who feels the increase in CO₂ and begins the feeling of panic.
The amygdala brakes this reaction, avoiding fear. Therefore, patients like SM, who do not have amygdala, have unexpected reactions – but scientists do not yet know why the amygdala behaves in this way.
“It is a scientifically very significant result, as it teaches us that the amygdala is not fundamental for all types and forms of fear, anxiety and panic”, according to Shackman.
“It seems crucial to orchestrate fear in response to external threats, such as the thief, the snake, the spider, the monsters that leave the house badly persecuted. But it does not seem to be responsible for triggering very strong panic sensations in response to this trigger inside.”
The evolutionary importance of fear
Of course, SM is only one person and scientific discoveries based on his experience will not necessarily be true for all the others.
The unique thing of your case is that your disease has almost completely destroyed your amygdala, leaving other regions of the brain intact. But people can react to the same type of brain injury in different ways.
In addition, the age in which the person suffers brain injuries also influences his recovery.
But the extraordinary story of SM highlights the reason why we evolve to create fear first. All vertebrates, including mammals, poultry, reptiles, amphibians and fish, have tonsils, which are clearly a great help for survival.
“When you hurt the amygdala and put the animal back in the wild environment, it will usually die in a few hours or days,” explains Feinstein. “And this is because, without this fundamental circuit of navigation in the outside world, these animals are in dangerous situations.”
But the patient SM managed to live for over half a century without his amygdala, also placed in very poor situations.
“One of the questions that attract my attention in his case is that this primary emotion of fear, in fact, may not be necessary in modern life”, reflects Feinstein.
“It can do more damage than well, especially in western societies, where many of our basic survival needs are satisfied, but we still observe the levels of stress and anxiety related disorders well beyond the expected levels. “
Read a Original version of this relationship (in English) on the site BBC innovation.
Source: Terra

Ben Stock is a lifestyle journalist and author at Gossipify. He writes about topics such as health, wellness, travel, food and home decor. He provides practical advice and inspiration to improve well-being, keeps readers up to date with latest lifestyle news and trends, known for his engaging writing style, in-depth analysis and unique perspectives.