Neural connections that may play a role in autism have been discovered

Discovery of feedback between two populations of neurons associated with social behavior in the mouse brain that may have implications for the understanding and treatment of autism in humans

autism. Illustration: shutterstock
autism. Illustration: shutterstock

Autism (Kener's syndrome) is a developmental disability that exists on a spectrum and whose causes, as researchers now believe, are hereditary and congenital. The syndrome is characterized, among other things, by difficulty in creating social relationships, speech disorder and repetitive behaviors.

Humans with autism tend to show an increased tendency for social isolation and a reduced frequency of social interactions when previous studies linked autism with dysfunction of an almond-like structure in the human brain called the amygdala. The role of the amygdala is related to regulating the functioning of the hormonal system and the autonomic nervous system, actions that have an impact on the regulation and processing of emotions and social behaviors.

Recently, researchers from the California Institute of Technology (Caltech), the postdoctoral student Weizhe Hong under the guidance of Prof. David Anderson, discovered in the amygdala of a mouse two populations of neurons that have a feedback effect on each other. One population encourages social behavior such as mating, fighting and playing, while the other population encourages asocial behavior or repetitive self-grooming; -oriented, in contrast to actions that indicate an external, social orientation - E.B.H.). This discovery, according to the researchers, can help to understand the neural dysfunction that underlies autism in humans and may also contribute to alleviating the syndrome. The study was published in Cell on September 11 of this year.

The "social" neurons are inhibitory neurons that release a neurotransmitter called GABA (gamma-aminobutyric acid, a non-protein amino acid that is the most common inhibitory neurotransmitter - GABA), while the "unsocial" neurons are excitatory neurons which release a neurotransmitter called glutamate (glutamic acid; glutamic acid which is one of the common amino acids in nature).

In addition to discovering the same populations of nerve cells, the researchers were also able to cause their activation in the amygdala in the mouse brain using a technique called "optogenetics". In this technique, the nerve cells are manipulated so that they are activated in response to light of a certain wavelength. This way, the researchers could choose which population of nerve cells to activate and see how this action affects the behavior of the mouse.

The behavior that resulted from the activation of the "social" nerve cells depended on the intensity of the light. Strong light intensity caused the mice to be aggressive in response to a mouse entering their territory, while weak light intensity caused the mice to be more relaxed social, for example courting the intruder or creating another social interaction with him.
Regarding the "non-social" neurons, when the light manipulation was applied to them, the mice started to lick their paws and faces while ignoring environmental intruders. This activity continued repetitively even after the light went out.

Another thing that the researchers noticed is a relationship of feedback or seesaw effect between the two populations of nerve cells. Activation of the "social" neurons suppressed self-involvement, while activation of the "non-social" neurons suppressed social behavior.
According to Anderson, this seesaw effect can be related to the autism syndrome in humans since in this syndrome there is a decrease in social interactions and an increase in repetitive actions which are often characterized by internal orientation (a phenomenon called perseverative).

In conclusion, the contribution of this research is mainly in the demonstration of the neuronal feedback effect in the cycle of self-preoccupation versus social preoccupation, a demonstration which is important for understanding the process. The researchers believe that it may be possible to apply this research to autism in humans, to carry out a process of therapy with the help of light and thus to activate a population of social nerve cells in order to prevent unwanted activities. On the other hand, there are doubts to what extent this research can also be applied to humans and there is no doubt that there is a long way to go for that.

 

· Full disclosure - the author of the article is the father of an autistic child

 

Link to the study on the Caltech website

13 תגובות

  1. point
    I do not understand. Do you think that autistic people should not be helped, or that the problem should not be prevented if possible?
    How is it different from any other disability?

  2. Miracles we all demonstrate our point well.
    The idea is that we all look for faults in others. It is not the autistics who cause suffering to humanity.

  3. It's embarrassing that so much research is being done on autistic people.
    Why don't they publish studies that have discovered neural connections related to general human stupidity.

    After all, there are many more stupid people (100% of humanity) than there are autistic people.

  4. Ran, if I separate for a moment the scientific part from the personal part and although I don't usually discuss such matters online, if you say that you are currently, at this age, diagnosed as autistic, then it may be Asperger's and not autism. Classic autism, as it was diagnosed in my son, is diagnosed at a fairly young age (two-three years old) and is not a pleasant thing at all. Strange movements, various impairments, inability to speak the language, misunderstanding of seemingly trivial things. The state, which is quite difficult to extract money from in other situations, immediately grants 100% disability for 10 years, with the assumption that it will last for life. I don't know if the definition "disease" is the correct definition, it is a type of developmental disability that can perhaps be improved with treatments but not really solved. Although the field of autism is not an area of ​​expertise, the material I read made it clear to me that the reasons for it are not really clear (explanation is in a genetic direction, so we conduct a genetic chip test for our son under the instructions of the neurologist, but not all researchers agree on the genetic matter). As for the future, things are even more ambiguous. It is indeed a spectrum, but at least in its center (even when it comes to high-functioning autism) the impairment is clear and definitely worthy of research and treatments (where part of the research is etiology and classification in order to be able to better distinguish the degrees of the spectrum).

  5. Ran, there is a wide spectrum of autism.
    As long as the autistic person can take care of himself at a certain age (be independent), I can agree with your words.
    But when there are many autistic people who will ever need a therapist.
    We still haven't talked about the terrible behaviors that some autistics have and causing suffering to families (not all autistics).

  6. Ran
    So how to treat it? If we look at it as a trait, like eye color, then the health care system has no reason to help or seek a solution. Alzheimer's is not a disease? Parkinson's?
    Are you really opposed to looking for a solution?

  7. I hate that autism is talked about like a disease, erm Robin erm, why can't people be allowed to be who they are?

    And in the spirit of the article, full disclosure: the writer of this comment may (in the stages of diagnosis) be autistic, and serves in the IDF despite the difficulty, and I wouldn't change it even if I could.

Leave a Reply

Email will not be published. Required fields are marked *

This site uses Akismet to filter spam comments. More details about how the information from your response will be processed.