Fall into childhood with benefits for the mind
How to awaken a child in an adult
Helen Thomson, New Scientist: Learning drugs reawaken grown-up brain's inner childThe material was prepared by the editors of InoSMI specifically for the RIA Nauka section
The medicine for achieving the perfect tonality in singing is just the beginning: it will be easier to master new skills and abilities if we are able to restore our children's brain abilities to create new circuits.
Listen up, potential maestros. A mood-stabilizing drug will help you achieve perfect hearing. You will be able to identify any note that you hear, and you will not need to look at the sheet music.
Since this skill is usually acquired at the beginning of life, this discovery was the first evidence that the human brain can be returned to a childish state. This will allow us to treat diseases and reveal in ourselves those skills that are very difficult, and sometimes impossible to acquire after reaching a certain age.
Many abilities, from bilingualism to athletic success, are embedded in neural circuits that are formed in early childhood on the basis of acquired experiences and sensations. Up to the age of seven, the brain goes through several "critical periods" when it can undergo radical changes under the influence of the environment. It is believed that at this time it acquires increased plasticity.
To take advantage of such critical periods, the brain should be appropriately stimulated so that it lays down the neural chains necessary for certain skills and abilities. For example, children with poor vision in one eye may develop blurred vision, or amblyopia. It can be cured by closing a healthy eye, because in such a situation the child will be forced to use an amblyopic eye. But this method of treatment works only in a critical period.
Such favorable moments are fleeting and fleeting, but scientists are beginning to understand what leads to their completion and how such moments can be repeated.
"We had a dogmatic idea that there are many plasticity factors in the young brain that disappear with age, and that this is why critical periods end," says Takao Hensch, professor of neurology at Harvard University. – Then we realized that no matter when the critical period begins, its duration is limited in time. This indicates the presence of gene programs, with the beginning of which plasticity stops."
Hensch's team proved that some physiological changes in animals close the doors of plasticity. The key factor here is the enzyme histone deacetylase, which affects DNA and makes it difficult to turn on and off certain genes.
Hensch and his colleagues came to the conclusion that if you change the direction of these molecular brakes, the plasticity of the brain can return again. "That's exactly what we found," says the scientist. In 2010, they used the drug valproate, which inhibits the action of histone deacetylase and is used to treat bipolar disorder to cure adult mice from amblyopia.
To establish whether valproate is capable of reawakening critical periods in humans, Hensch, together with colleagues and Alan Young from King's College in London, had to settle for a skill that an adult would seem unable to acquire. They chose perfect hearing because it is a very rare ability and it is usually observed in people who are taught music before the age of six. There are no convincing examples in the world that a person can acquire this skill in adulthood, although people can acquire certain abilities to recognize notes after months of rehearsals and training.
For 15 days, a group of researchers gave valproate or a harmless sedative to 24 men who had no musical education or had a minimum of musical training. In the second week, the participants of the experiment were shown a 10-minute training video every day, in which they were taught to associate six different tones in three octaves with six names, such as Sarah, David and Jimmy. Scientists used the names of people, not the names of notes, so that the acquaintance of the participants of the experiment with the notes could not affect its results.
On the last day, a group of test subjects were given 18 different tones to listen to and asked to name them by association. Those men who took valproate, on average, named 5.09 notes, and this indicator turned out to be much better than those who took the usual sedative, as they showed a result of 3.5 correctly named notes, which is no better than random guessing.
This study (Gervain et al., Valproate reopens critical-period learning of absolute pitch, Frontiers in System Neuroscience, 2013 – VM) was a promising first step showing that adults in critical periods can also demonstrate cognitive abilities. This is what a psychologist from the University of California at San Diego, Diana Deutsch, says. "The number of participants in the experiment in this case was small," she explains. "However, the results were significant, and they should be taken seriously."
Now the research team will try to repeat these results in a larger experiment, in which an additional group will take part, taking mood stabilizers that do not affect histone deacetylase.
Studies on other drugs are also being conducted. One of them affects another inhibitory mechanism that affects plasticity, and the experiment is carried out with genes that weaken the movement of the nutrient choline through the cell. A drug for the treatment of Alzheimer's disease called donepezil enhances this movement. Therefore, a group of researchers from Boston Children's Hospital, which includes Hensch, is trying to find out whether this drug is able to stop the development of amblyopia in older children and adults. The results are encouraging, says Hensch. "The condition of the first group of study participants improved. We don't know how long this will last, and we are currently studying this issue." Another study focused on the antidepressant fluoxetine, better known as prozac.
But scientists are acting with great caution. The brain stops critical periods for a reason. It will be a disaster if he spends the rest of your life endlessly mounting and remounting his circuits. Hensch says he would be wary of testing the effects of valproate on humans if it wasn't a proven and approved drug for the treatment of mood disorders and epilepsy. "We are not opening the brain for major restructuring. We are simply increasing its plasticity potential. Coupled with training, this can manifest itself in the changes we need."
The consequences of such work are difficult to predict, says Yang, but they can be very serious. Some disorders, including autism, may be the result of critical periods coming at the wrong time. Therefore, their return can be beneficial in terms of treatment. In addition, there is an opportunity to give us new skills and abilities. "If you can rediscover this critical period, you have the potential to awaken the desire for knowledge in everything," says Yang.
Our developing brain is incredibly malleable and elastic. It is able to structure and restructure the connections between nerve cells in response to various sensations and impressions. The time of the largest changes or "sensitivities" is called critical periods. They begin at the end of a certain age, which allows the brain to create and strengthen the connections and mechanisms responsible for hearing, vision, emotions and speech.
Creating such chains requires a delicate balance between arousal and deterrence. Excited or in an active state, nerve cells form strong connections, help in creating new chains, and restrained or inhibited neurons that fall out of the synchronous process can be removed.
Scientists have shown that certain drugs can stimulate the onset of critical periods in adults. This not only gives us the opportunity to acquire new skills and knowledge, but can also provide an effective way to combat neurological disorders. For example, many genes involved in autism are involved in creating and maintaining a balance between arousal and deterrence. Some researchers believe that the cognitive impairment observed in autism may be the result of untimely critical periods. In the course of experiments on mice that were bred with the expression of genes responsible for autism, evidence of such violations in time was found.
If the critical period comes at the wrong time, the brain can create certain chains too early. And this means that they will connect to underdeveloped areas of the brain. Or it may happen too late, and in this case, the functions for which these chains are responsible, for example, the ability to recognize facial features and expressions, will not be combined into a single whole with more complex neural processes such as those that help us understand and interpret the emotions of other people.
Portal "Eternal youth" http://vechnayamolodost.ru10.01.2014