Soul and body in the hand of the genome

The long journey to decipher the north of the soul - in the framework of which the anxiety gene was recently discovered - is integrated into the effort to identify the genetic causes of hereditary diseases. If he succeeds, he will usher in a new era in the field of psychiatry

  
Genes for adventurousness and anxiety were recently discovered, following studies to which many scientists in Israel contributed. These soul traits, it turns out, may be determined, even if only partially, by the person's hereditary material - the DNA. The mind finds it difficult to grasp that the same genetic complex that determines the color of the eyes, the height and the shape of the nose may also control our most hidden features - the characteristics of our personality or the way in which emotions arise in us.

Few would deny the idea that human behavior has a biological-hereditary basis. Everyone knows the anecdotal evidence regarding the surprising similarity in character traits between a child and his parents or between a brother and sister. Studies have even proven beyond any doubt that identical twins, even if raised separately, tend to share mental traits such as intelligence, introversion and sexual preference, to a degree that far exceeds that found among non-identical twins and ordinary siblings. The obvious conclusion - the identity of the DNA sequence in identical twins is what makes them similar in the field of emotion as well. It is clear that the environment also has a substantial effect on the behavior, because even in identical twins, considerable personality differences are noticed. Behavior is therefore determined by a combination of genetics and environment. While the influence of the environment is difficult to study precisely, the modern tools of genome research make it possible to decipher the hereditary components of behavior and emotion. These discoveries are of enormous importance in deciphering mental illnesses and in understanding the functioning of the brain.

Many instinctively oppose the idea that the soul, that ethereal complex of "immaterial" properties, is an outgrowth of a strictly material organ - the brain. In ancient times, they believed, and this belief has not faded to this day, that the soul has a separate existence from the body. Phrases such as "his soul departed" testify to this, and soul-body duality is still considered a legitimate issue in the field of philosophy. But modern science offers a clear alternative: the brain, an array of nerve cells whose complexity exceeds all imagination, is the one that produces all the qualities of emotion -
Love and hate, enjoyment of poetry and music, anxiety and a sense of adventure.

In fact, it is not necessary to resort to the wonders of modern genetics to be convinced of the plausibility of this concept. It has been known for many years that the communication between brain cells is essentially chemical, and the "protocols" of this communication have been studied in detail. It was discovered that each of the millions of cells in the brain "transmits" with the help of a specific chemical messenger, a neurotransmitter, and that this transmission is received by the target cells with the help of unique receptors. The drugs that psychiatrists prescribe for the treatment of mental illnesses, as well as addictive drugs such as heroin and LSD, are actually biochemical mimicry of the brain's messengers. And since it is known that such imitative substances have a tremendous effect on emotions and feelings, it is understood that emotion is the result of a chemical process. Modern molecular genetics makes it possible to take another significant step towards understanding the material basis of behavior. The genome, the hereditary complex of a person, includes about one hundred thousand units - the so-called genes. Each gene encodes a protein - the execution unit of the animal world. Now one can ask, which structural unit of this huge complex is responsible for a certain mental trait, such as a tendency to anxiety, depression or alcoholism. The resulting picture is not simple: it turns out that the qualities of the soul are determined by a complicated combination, in which several genes contribute together to the final result. This is in contrast to traits that are determined by a single gene, such as eye color, or the ability to feel the taste of the substance PTC (some feel its bitter taste and some don't). Each of the five thousand hereditary diseases, such as hemophilia and Tay-Sachs, is caused by a defect in one gene, which makes it somewhat easier to understand them. In contrast, the common diseases, such as hypertension, diabetes and Alzheimer's, are similar to mental traits in that they are the result of combining defects in many different genes, which makes them difficult to decipher.

How, then, is it possible to find out the contribution of a single gene to this or that mental trait?
With the help of sophisticated statistical tools. The existence of a gene that affects a tendency to anxiety was recently proven in the research of Dr. Yonatan Benjamin from Ben Gurion University and his colleagues in Germany and the USA. The researchers carefully compared personality traits, revealed by questionnaires, with the presence of versions of different lengths of a certain gene. It turns out that the owners of the short garden have a tendency to anxiety that is somewhat higher than that of the owners of the long garden. This difference can only be discovered by mathematical analysis of results obtained from two large groups of people.

What considerably strengthened the conclusions of the study was the nature of the garden in question. This is a gene for a protein called serotonin transporter. Its role is to retrieve the chemical messenger serotonin and remove it from the spaces (synapses) between the nerve cells in certain brain areas. And here, it has been known for years that drugs that inhibit this protein, and therefore increase the amount of serotonin in the interneuronal spaces, successfully prevent anxiety and depression. This is how the research circle is closed: a natural variation in the encoding gene, and a drug that binds to the protein encoded by it, simultaneously affect the same mental trait. But it is clear that there are other genes involved in the mental state, and only if they are all discovered will it be possible to accurately predict a person's tendency to depression and anxiety. The long journey to deciphering the north of the soul is integrated into the international effort to identify the genetic causes of the "multigenic" diseases. Genome researchers all over the world are rallying around this goal, along with leading pharmaceutical companies and the medical and biotechnological establishment. If you succeed, this initiative will bring a new era in the field of psychiatry and medicine as a whole. In this future world, the gene combinations that cause physical and mental illnesses will be known. Knowing the coding genes will allow the decoding of the structures of the encoded proteins. This knowledge, combined with computer technologies of the next millennium, will enable the sophisticated design of new drugs, which will alleviate mental conditions without side effects. In special cases, a futuristic strategy of gene therapy will even be possible - replacing damaged genes with normal ones. But most importantly - the knowledge that will be obtained from genome research will allow a person to understand himself better. Then, while strictly adhering to the rules of ethics, it will perhaps be possible to prevent the ability of personality-determining genes to bring destruction and pain to the world.