Our brain has many reactions to what happens around us for this reason a group of French researchers have discovered how the brain alerts us to the danger: a population of neurons located in the middle prefrontal cortex recognizes alarming information from the environment and sends signals to the trunk brain, which triggers the liberating reaction. The result will be helpful in dealing with post-traumatic stress.
Living beings are able to integrate and identify sensory information that interests us, such as smells, sounds and light, in order to regulate our response to these environmental stimuli in situations of danger.
This ability of the brain to recognize specific information is called “contextual discrimination.” What these researchers have achieved, according to a statement from the National Institute of Health of France (Inserm), is not only to discover which neurons are involved in these processes, but also that they are located in the middle prefrontal cortex of the brain.
The prefrontal cortex or prefrontal cortex is the anterior part of the frontal lobes of the brain, and is located in front of the motor and premotor areas. This brain region is involved, among other functions, in the decision-making processes and in the adaptation of the appropriate social behavior in each moment.
To achieve this result, researchers have resorted to optogenetics, a combination of genetic and optical methods to, by means of light, control specific events of living tissue cells, without altering their biological functioning.
In this specific case, optogenetics has allowed researchers to activate or inhibit populations of neurons in order to determine their involvement in a specific behavior. To do this, they introduced light-sensitive proteins into the neurons of the mice. In this way, they managed to discover those that are involved in contextual discrimination, as well as their causal relationship with this process.
They did the experiment with laboratory mice, to evaluate the neural circuits involved in contextual discrimination. They placed the rodents in an environment with different sensory stimuli such as light, smell and sound, in which they received assiduously mild electric discharges to perceive that environment as adverse.
At another point in the experiment, the mice were placed in the same environment, but without the sensory stimuli of smell, sound and light, making them believe that they were in a peaceful environment.
During the experiment, the activity of the neurons of the average prefrontal cortex of the mice was subjected to permanent observation and optogenetic manipulation, which allowed the researchers to identify the population of neurons that was activated during contextual discrimination.
In this way they were able to confirm that the neuronal activity of this specific area of the brain is basic for contextual discrimination and to alert us to a danger. They also observed that this population of neurons sends signals to the brain stem, the area of the brain directly involved in the motor regulation of emotional behaviors.
The result is important because until now it was not known what were the neural circuits involved in dangerous situations. It was only known that the process of contextual discrimination came from the hippocampus.
Help with post-traumatic stress
The anatomical and psychological data obtained in this research indicate that a structure called the dorsal mid-prefrontal cortex, located in the frontal part of the skull, receives the neural influences of the hippocampus, the authors explain in their article.
They add that the dorsal medial prefrontal cortex of the brain is activated during moments of uncertainty, so it becomes an ideal candidate to develop contextual discrimination.
This result will help, particularly, people suffering from post-traumatic stress, according to the researchers.
Post-traumatic stress disorder or PTSD is characterized by the appearance of specific symptoms after exposure to a stressful, extremely traumatic event, involving physical harm, or a serious or catastrophic threat to a person.
In people, PTSD is associated with a contextual generalization, as opposed to a contextual discrimination: the affected people are not able to integrate and identify the sensory information emanated from the environment, and therefore lose the ability to react to a danger. Now we know the neural circuits that are involved in this anomaly.Visitas: