Could a severe infection in the womb raise chance of autism? Scientists make ‘unexpected’ discovery after studying children’s brains

Scientists believe they’ve found more evidence of what causes autism and other neurological conditions.

A team from the University of Maryland discovered that inflammation stunts the growth of specific neurons in the part of the brain responsible for motor control and language, social skills, and emotional regulation. 

Previous research has shown that babies born with abnormalities in the cerebellum often go on to experience neurodevelopmental disorders like autism and schizophrenia, and animal models exposed to inflammation before birth also develop the conditions. 

There are many things that can cause inflammation in the developing brains of babies, including a severe infection in the womb, according to study co-leader Dr Seth Ament. 

Dr Margaret McCarthy (pictured) is the co-leader of the research at the University of Maryland, which found that inflammation in children’s brains can disrupt the growth of two key neurons — the Golgi and Perkinje neurons

The researchers looked at the brains of 17 children who died between the ages of one and five.

Eight died from inflammatory conditions such as bacterial or viral infections or asthma, which were compared to the remaining nine who died from a sudden accident.

None of the children had been diagnosed with a neurological disorder before they died, and the two groups were similar in age, gender, race and ethnicity and time since death.

The scientists found that the brains of the children who died from illness or allergy all had the same changes. 

Two specific but rare types of neurons — the Golgi and Perkinje neurons — appeared to have had their growth disrupted due to the inflammation, meaning they were not fully developed and could lead to disorders like autism.

Children are born with autism and cannot develop it, as far as researchers know, which means the inflammation must occur during development in the womb.

Scientists are still not completely sure what the cause of many neurodevelopmental disorders are, but the findings could lead to more and better treatments for disorders that begin in childhood.

Dr Dean Gladwin, a physician-scientist at the university, said: ‘It’s critical to understand these mechanisms and changes at the cellular level during brain development in the hope that someday we can develop treatments for neurodevelopmental disorders.’

Dr Ament told Newsweek: ‘The donors in our sample experienced acute inflammation from causes such as encephalitis and severe asthma attacks.

‘In addition, some donors were identified as having experienced inflammation because their medical records indicated the use of anti-inflammatory drugs.’

Dr Ament said: ‘We looked at the cerebellum because it is one of the first brain regions to begin developing and one of the last to reach its maturity, but it remains understudied.

‘With the fairly new technology of single nucleus RNA sequencing we could look at the cell level to see changes in the brains.’

Co-leader Professor Margaret McCarthy said: ‘This has never been done before in this age group and in the context of inflammation.

‘The gene expression in the cerebella of children with inflammation were remarkably consistent.’

Dr Ament said: ‘Although rare, Purkinje and Golgi neurons have critical functions.

‘During development, Purkinje neurons form synapses connecting the cerebellum to other brain regions involved in cognition or emotional control, while Golgi neurons coordinate communication between cells within the cerebellum.

‘Disruption of either of these developmental processes could explain how inflammation contributes to conditions like autism spectrum disorders and schizophrenia.’

He said, as with many diseases, both genetics and the environment – in this case, inflammation – likely contribute to the risk of developing the disorders.

Dr Ament said that’s why it is crucial to understand the roles of specific cells within the brain regions – as well as how they interact with genes to influence brain function – to find treatments for brain disorders, such as autism and schizophrenia, as well as others including dementia, Parkinson’s disease, or substance use disorders.

He told Newsweek: ‘Dr McCarthy previously found a postnatal critical period in rats during which inflammation blunts the development of Purkinje neurons, so it was very encouraging for us to see similar effects in humans.

‘By contrast, our findings for Golgi neurons were more unexpected and open up a new line of investigation.’

The new study, published in the journal Science Translational Medicine, is part of a collection of more than 20 papers describing the development and diversity of cell types in the human brain.

While the research may provide additional information that could help generate new treatments for conditions like schizophrenia and autism, it is not clear whether targeting inflammation would completely stop its effects on brain development.

Autism affects one in 36 children, meaning that more than 90,000 children are born annually with the developmental disorder in the US.

It is characterized by problems with social communication and interaction, difficulty expressing oneself and repetitive behaviors and interests.