A new study in mice has discovered that a dysfunction of the inner ear can cause neurological changes that increase hyperactivity. The research, which has been conducted in the United States by scientists at the Albert Einstein School of Medicine at Yeshiva University in New York, has identified two proteins of the brain that are also involved in the process.
For years it had been observed that many children and adolescents who suffered from disorders of the inner ear, especially if they were serious problems affecting both hearing and hearing. Balance, they also presented behavior problems, like hyperactivity. However, no link was found to associate them.
Disorders of the inner ear - formed by the cochlea, responsible for hearing, and the vestibular system, which is responsible for balance - may be due to genetic defects, or be caused by an injury or infection.
Disorders of the inner ear cause a dysfunction in the striatum, an area of the brain that controls movement
A doctoral student at the Einstein School observed that some mice from the laboratory of Dr. Jean M. Hébert, who has led the research, were in a constant state of movement. When evaluating them, the researchers verified that these animals were deaf due to serious cochlear and vestibular defects, related to a mutation in a gene -Slc12a2-, which intervenes in the transport of sodium, potassium and chloride molecules to different tissues, including the inner ear and the central nervous system.
When carrying out tests on healthy mice, they found that when the internal ear gene was suppressed, there was an increase in its locomotor activity. According to the authors of the work, disorders of the inner ear cause dysfunction in the striated body, an area of the brain that controls movement. And they also discovered that they increased the levels of two proteins -Perk and pCREB-, which intervene in the control of the action of neurotransmitters.
According to the results of the study, researchers believe that hyperactivity in children suffering from inner ear disorders could be controlled with drugs that inhibit Perk in the striatum. Hébert explains, moreover, that the research raises the possibility that certain sensory deficits not related to defects of the inner ear could also cause or facilitate the development of other mental or motor disorders that are currently considered solely of cerebral origin.