”Look, there’s a lunatic there.”
”I heard he was possessed by a ghost.”
This may be the conversation that the ancients had when they encountered mentally abnormal people.
Until a scientific explanation emerged, “crazy” and being possessed by “ghosts” were often synonymous with schizophrenia. In fact, schizophrenia is just a disease. Unlike colds and fevers, it is a mental illness. Generally, it is caused by abnormalities in the patient’s neural circuit, which produces symptoms such as hallucinations, hallucinations, and delusions, also known as mental illness.
The exact cause of schizophrenia is not yet clear, but about 80% of schizophrenia is considered to be genetically caused, so researchers believe that genes are the “culprit” for causing such diseases. So how do researchers speculate that genes cause schizophrenia? And why are these genes that are not good for the human body not being eliminated, but can be inherited? What genes are these “culprits”? Next we will discuss them one by one.
Some modern human disease genes
suggested that schizophrenia is a modern unique, it is the evolution of modern man, the disease gene changes produced.
In this theoretical background, scientists have compared the genes of modern and extinct Neandertals. If the genes that cause schizophrenia are really unique to modern people, then the Neandertal genome is These genes would not appear.
The comparison results show that although the genetic sequence of modern people is very similar to that of Neanderthals, there is a gene region in modern human genomes that Neanderthals do not have, and this region happens to be the cause of schizophrenia. A genetic region. So researchers believe that the genes in this area may be the genes of modern people, which are unique to modern people, and these changed genes may be the cause of schizophrenia in modern people.
Escaped natural selection causes
confusing it is that these genes turned out to be unfavorable to escape the strong natural selection, and retained the tens of thousands of years, this is why?
Some studies have suggested that, while they bring diseases to humans, they will also bring significant species advantages to humans, such as better language skills, logical thinking ability, and creativity. Even some patients with schizophrenia will Have extraordinary talent.
John Nash, who won the Nobel Prize in Economics, is considered to have schizophrenia; Van Gogh, one of the world’s most famous painters, has done many weird and incomprehensible things, such as cutting his ears, Also considered to be suffering from schizophrenia; San Mao, a big pearl in the literary world, was revealed to have symptoms of hallucinations and delusions early, and it is suspected of suffering from schizophrenia …
In addition to bringing species advantages, there are studies It is believed that although these altered genes may cause modern schizophrenia, at the same time these genes also play an important role in building a healthy prefrontal cortex, and a healthy prefrontal cortex can usually prevent humans from suffering from schizophrenia.
In the prefrontal cortex, there is a neurotransmitter called GABA, which is an important inhibitory neurotransmitter in the central nervous system. In healthy prefrontal cortex, the transmission of GABA in the neural circuit is normal, it can inhibit some nerve impulses, and avoid excessive excitement or fantasy.
But when these genes change, the incomplete prefrontal cortex construction may cause GABA to fail to transmit. At this time, the nerve impulses are not properly suppressed, and people will become extremely excited, and even have symptoms such as delusion, which happens to be Common symptoms of schizophrenia.
Therefore, although the existence of the “culprit” gene may cause modern schizophrenia, it may also improve human intelligence and build a healthy prefrontal cortex, which may be the reason why they escaped natural selection.
Disease genes uncovered
mentioned before, a specific region of the modern gene present in the genome of schizophrenia may be caused by the “culprit”, the “culprit” escaped the screening of natural selection, but scientists can not escape The “law eye”.
Recently, many scientists have carried out in-depth research on this unique gene region of modern people. They believe that this gene region is one of the “culprits” that triggers schizophrenia, and they have named this region “the accelerated region of human evolution”, and The genes in this area are rapidly evolving. Some studies have found that the genes in this region can cause schizophrenia because some genes in the accelerated human evolution region can regulate dopamine levels.
Dopamine, like GABA, is a neurotransmitter. Unlike GABA, it does not inhibit nerve impulses, but promotes the transmission of nerve impulses, which makes the body excited and happy. When these genes do not regulate the dopamine level improperly, dopamine excess may occur, and excess dopamine may cause hyperactive or fantasy symptoms in the body. Therefore, dopamine excess is considered to be one of the causes of schizophrenia.
In addition to the human accelerated evolution zone, researchers from Japan have also locked in another “culprit accomplice”-the RTN4 gene. As mentioned earlier, the causes of schizophrenia are abnormalities in the neural circuit, including abnormalities in neural signal transmission. The study found that when the RTN4 gene functions normally, the transmission of neural signals is normal, but when the RTN4 gene is abnormal, the transmission will also be abnormal.
A new study has found another gene that may cause schizophrenia, the CACNA1C gene, which has given us an evolutionary advantage. It may give us a more fully evolved brain, which is often accompanied by a higher risk of schizophrenia.
It turns out that genetic changes bring us not only a brain capable of complex cognition, but also a human-specific BUG—schizophrenia.
”Look, there’s a lunatic there.”