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 first operations on the corpus callosum were done by doctors to cure epilepsy. The connection between the hemispheres was broken, and the patients were really cured of epileptic seizures. Over time, scientists began to notice some side effects in these patients - their abilities changed, behavioral reactions were disrupted. It was experimentally revealed that, having undergone such an operation, the “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.
The corpus callosum was stopped to dissect to cure epilepsy. For scientists, a whole layer of activity has been opened 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. The dependence of its influence on differences in behavior and abilities is assumed.
The 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 physical coordination of the body and the processing of information, their joint work is necessary. The corpus callosum of the human brain is the connector of the right and left hemispheres, thereby providing a connection between them. It serves as a guide, and that is why it is not distinguished as a department.
Structure
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 generally transverse direction of fibers that connect the symmetrical locations of the hemispheres. But there are fibers that connect and asymmetric places. For example, the parietal gyrus of the right hemisphere with the frontal left.
Corpus callosum departments:
Each of them performs its function.
- The front is the knee. The name is associated with its shape - first elongated, then bent down. Goes to the keel (beak). He goes to the terminal plate. Here interhemispheric fibers of the frontal lobes are connected.
- The middle section is the trunk. It has the shape of a rectangle. It is located in the middle of the corpus callosum and is its longest part. Here the fibers of the parietal and frontal lobes converge.
- The back section is the roller. It is a thickening. Here the fibers of the posterior temporal lobes and the occipital lobes are closed.
In the upper part, the corpus callosum is covered with a thin layer of gray matter. Moreover, in some areas, longitudinal thickenings similar to stripes are formed. The anterior cerebral arteries are the main source of blood supply to the corpus callosum, and the venous outflow of blood takes place along the venous bed located under it.
Functions
The main and almost the only function of the corpus callosum is the transfer of information from one hemisphere to the other and the maintenance of normal human life 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 workers 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). Throughout childhood, it develops. By the age of 12, the corpus callosum is fully formed and remains unchanged. Recently, an increase in congenital malformations has been recorded in the structure of the incidence of newborns, where anomalies in the development of the spinal cord and brain are occupied by 10 to 30%.
Agenesis of the corpus callosum
This is a rather rare anomaly, which is observed in about 1 person out of 3000. This is a complete or partial absence of the corpus callosum in the structure of the brain in the baby 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 abnormalities;
- infections and viruses transmitted during pregnancy (toxoplasmosis, rubella, flu);
- ingestion of toxic substances, including alcohol and drugs;
- consequences of the use of medicines during pregnancy;
- radiation exposure;
- metabolic disorders during pregnancy in the mother's body.
Carriers of the gene causing the anomaly can be parents - the so-called recessive genetic disorder. The corpus callosum can also be affected. Children with its anomaly very often lag behind in development: they can be blind or deaf, not be able to walk or talk.
Diagnosis of agenesis, its symptoms and treatment
It is usually diagnosed during 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.
To confirm the diagnosis, visualization is necessary using:
- 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:
- impaired vision and hearing;
- low muscle tone;
- disturbances in the work of the organs of the gastrointestinal tract, having different intensity and nature;
- behavioral problems;
- hydrocephalus;
- trouble sleeping
- psychomotor disturbances;
- cramps
- the appearance of tumors in the brain;
- hyperactivity
- impaired coordination of movements.
Identified symptoms of agenesis can be treated. Most often this is drug therapy, in some cases - physical therapy (physical therapy).
Agenesis can be combined with other brain abnormalities, such as:
- Arnold-Chiari syndrome;
- hydrocephalus (excessive accumulation of cerebrospinal fluid in the ventricular system of the brain);
- impaired neural transmission.
It can be combined with a cleft in the spine.
Corpus callosum hypoplasia
This is a serious, but rather rare (1 case per 10,000) anomaly. With hypoplasia, the corpus callosum is present, but it is underdeveloped. The disease forms in the embryo in the 1-2 trimester of pregnancy. The reasons have also not been fully established, but the possible factors affecting the underdevelopment of the corpus callosum are similar to those described above.
The disease is diagnosed most often in the period of intrauterine development. The consequences that hypoplasia can lead to:
- retardation of mental and physical development;
- impaired intelligence (in moderate and severe form);
- mental retardation (in 70% of cases);
- various neurological problems.
A complete cure for this disease, as well as agenesis, is impossible with modern medicine. Treatment aims to reduce symptoms. Patients are advised to perform a special set of physical exercises, which helps to restore communication 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 to take care of your mothers health during pregnancy. Indeed, 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 are drug therapy and physiotherapy exercises (LFK).