A group of scientists led by Roger Sperry in the sixties of the last century discovered the functions of the corpus callosum of the brain, and in 1981 he received the Nobel Prize. For a long time, this part of the brain was a mystery - scientists could not fully understand its function.
Study history
The doctors did the first operations on the corpus callosum to cure epilepsy. Communication between the hemispheres was broken, and patients were actually cured of epileptic seizures. Over time, scientists began to notice some side effects in these patients - their abilities changed, behavioral reactions were disturbed. Experimentally, it was revealed that, having undergone such an operation, a "right-hander", for example, could not draw with his right hand and write with his left. There were other deviations, for example between conscious behavior and unconscious reactions. One man who underwent such an operation said that he loved his wife, but at the same time he hugged her with his right hand and pushed her away with his left.
Corpus callosum stopped dissecting to heal fromepilepsy. A whole layer of activity has opened up for scientists to study the functions of each hemisphere of the brain. In recent decades, sexual dimorphism (differences) in the size of the corpus callosum in men and women, as well as in people in general, has been actively discussed. It is supposed to depend on its influence on differences in behavior and abilities.
Concept
Each hemisphere of the brain controls the opposite half of the body: the left - the right side, the right - the left. Each of the hemispheres also controls certain functions. To ensure the physical coordination of the body and the processing of information, they need to work together. The corpus callosum of the human brain is the connector of the right and left hemispheres, thus providing a connection between them. It serves as a conduit, which is why it is not singled out as a department.
Building
The structure of the corpus callosum is a plexus of nerve fibers (up to 250 million). It has a wide and somewhat flattened shape. The corpus callosum has a mainly transverse direction of fibers that connect the symmetrical places of the hemispheres. But there are fibers that also connect asymmetrical places. For example, the parietal gyrus of the right hemisphere with the frontal gyrus of the left.
Departments of the corpus callosum:
- front;
- medium;
- rear.
Each of them performs its own function.
- Front section - knee. The name is associated with its shape - at first it is elongated, then it bends down. Turns into a keel (beak). He goes intoterminal plate. Here the interhemispheric fibers of the frontal lobes are closed.
- The middle section is the trunk. Has the shape of a rectangle. It is located in the middle of the corpus callosum and is its longest part. This is where the fibers of the parietal and frontal lobes converge.
- Rear section - roller. It is a thickening. Here the fibers of the posterior temporal and occipital lobes meet.
In the upper part of the corpus callosum covers a thin layer of gray matter. At the same time, longitudinal thickenings similar to stripes form in some areas. The anterior cerebral arteries are the main source of blood supply to the corpus callosum, and the venous outflow of blood occurs through the venous bed located under it.
Functions
The main and practically the only function of the corpus callosum is the transfer of information from one hemisphere to another and ensuring the normal functioning of a person due to the synchronism of their work. Therefore, it is an important part of the brain. Studies have shown that rupture of the corpus callosum leaves both hemispheres working and does not lead to death. However, they work in a separate mode, which affects human behavior.
Formation
The formation of the corpus callosum occurs in the brain of the embryo, usually at the end of the first trimester of pregnancy (12-16 weeks). All childhood it develops. By the age of 12, the corpus callosum is fully formed and remains unchanged. Recently, in the structure of morbidity in newborns, an increase in congenitalmalformations, where from 10 to 30% are malformations of the spinal cord and brain.
Agenesis of the corpus callosum
This is a fairly rare anomaly that occurs in about 1 in 3000 people. This is the complete or partial absence of the corpus callosum in the structure of the brain in a child at birth. Violation of its formation in the fetus occurs between the fifth and sixteenth weeks of pregnancy.
Specific causes of developmental disorders have not yet been established, but possible factors have been identified:
- genetic anomalies;
- infections and viruses during pregnancy (toxoplasmosis, rubella, influenza);
- ingestion of toxic substances into the body of a pregnant woman, including alcohol and drugs;
- effects of using medications during pregnancy;
- radiation exposure;
- violation of metabolic processes during pregnancy in the mother's body.
Carriers of the gene that causes the anomaly may be parents - the so-called recessive genetic disorder. The corpus callosum may also be affected. Children with its anomaly are very often retarded in development: they may be blind or deaf, unable to walk or speak.
Diagnosis of agenesia, its symptoms and treatment
Usually diagnosed within the first two years of a child's life. The first signs are often epileptic seizures. The disease may go unnoticed for several years if the case is mild.
Imaging required to confirm diagnosishelp:
- perinatal ultrasound;
- magnetic resonance imaging (MRI);
- computed tomography.
But there are some common symptoms that indicate the presence of agenesis and the need for immediate professional diagnosis:
- vision and hearing impairments;
- low muscle tone;
- disturbances in the work of the organs of the gastrointestinal tract, having different intensity and nature;
- behavioral problems;
- hydrocephalus;
- sleep problems;
- psychomotor disorders;
- convulsions;
- appearance of tumors in the brain;
- hyperactivity;
- discoordination of movements.
Identified symptoms of agenesis can be treated. Most often, this is drug therapy, in some cases, exercise therapy (exercise therapy).
Agenesis can be combined with other brain anomalies such as:
- Arnold-Chiari syndrome;
- hydrocephalus (excessive accumulation of cerebrospinal fluid in the ventricular system of the brain);
- neural transmission disorders.
May be combined with spina bifida.
Hypoplasia of the corpus callosum
This is a serious but rather rare (1 in 10,000) anomaly. In hypoplasia, the corpus callosum is present but underdeveloped. The disease is formed in the embryo in the 1-2 trimester of pregnancy. The reasons are also not fully established, butthe possible factors influencing the underdevelopment of the corpus callosum are similar to those described above.
The disease is diagnosed most often during fetal development. Consequences that hypoplasia can lead to:
- mental and physical retardation;
- intellectual impairment (moderate and severe);
- mental retardation (in 70% of cases);
- various neurological problems.
Complete cure of this disease, like agenesis, is impossible by modern medicine. Treatment is aimed at reducing symptoms. Patients are recommended to perform a special set of physical exercises, which helps to restore connections between the hemispheres, and information-wave therapy.
Thus, despite its small size, the corpus callosum plays a very important role in people's lives. Therefore, it is very important for mothers to take care of their he alth during pregnancy. After all, it is during this period that possible deviations in the development of the corpus callosum are formed.
Scientists, despite all their attempts, have not yet been able to study this structure to the end. Therefore, there are a small number of strategies for treating the symptoms of these anomalies. The main ones among them are drug therapy and physiotherapy exercises (LFK).
