Possible link between neural circuit and impaired social skills in autism

[Image source: Pixabay]

A South Korean team of researchers recently discovered a specific brain neural circuit that could be associated with the lack of social skills prevalent in those with autism.

The findings were unveiled on Tuesday by a research team led by Kim Eun-jun, a professor at Korea Advanced Institute of Science & Technology (KAIST). Kim, who also heads the Synaptic Brain Disease Research Center at the Institute for Basic Science (IBS) pointed to the neural circuit in the brain as the root cause of impaired social skills, a prominent symptom of autism.

Autism, or autism spectrum disorder (ASD), refers to a broad range of challenges with social skills and repetitive behaviors, with 2.8 percent of the world‘s population suffering from the disorder. Although ASD’s prevalence in the world is rapidly increasing every year, its exact cause remains unknown and there are no approved medications.

Neural circuits are various populations of neurons across the brain that carry out specific functions when activated, and little is known about the link between autism and the brain’s neural circuit.

The research team previously discovered that mice exhibiting autism-like symptoms due to the absence of the synaptic protein IRSp53 had neurons that were excessively activated in the prefrontal cortex. They also found a link between this heightened neuronal activity and the social disabilities observed in autism patients.

In its latest study, the team confirmed that the overactivated neurons in the brain destroy the reward circuit in the hypothalamus and midbrain, which can trigger a decline in social skills for people with autism.

The reward pathway, one of the brain’s neural circuits, motivates people to repeat behaviors that are necessary for survival. When the circuit is activated, people become inclined to engage in behaviors that make them feel positive emotions, which might also enhance their social skills. The reward pathway’s neurons are responsible for the release of dopamine, a neurotransmitter that can lead to positive feelings.

However, the over-activation of the prefrontal cortex in the autistic mice led to an abnormal suppression of their reward pathways located in the hypothalamus, which could explain the lack of social skills in autism patients, the researchers said.

As the team stimulated the mice’s reward pathways using light, the cells responsible for dopamine release returned to their normal conditions.

“We will conduct follow-up research to discover more brain areas and neural circuits that might be associated with ASD symptoms,” Kim said. The findings were released in the international journal Molecular Psychiatry.