Autism and The Gut: Who Is The Real Culprit?
The first thing you think of when you hear the word “Autism” is a problem with someone’s head or more accurately, their brain. It doesn’t mean that is always the case though.
According to the World Health Organisation (WHO), the prevalence of Autism Spectrum Disorder among children is around 1 in 160. A worrying number.
When it comes to our brains, there is a fundamental and repetitive format as to how its cells connect and communicate with each other. The junction between one brain cell (also called a neuron) and the next one is called a synapse. This is where the magic happens. An electrical signal reaches the end of a neuron, leading to the release of molecules and that conveys a signal to the next neuron.
The neurons in the land down under
Away from the brain and down to business. An often overlooked part of the nervous system is the one in our guts. A neuroscience professor used to rant about this last semester talking about how many neuroscience textbooks ignore it. He says the issue is providing an extremely watered-down version and failing to address the complexity.
It’s obviously significant though, because guess what takes over digestion after food slips into the stomach? A complete nervous system contained within us. The Enteric Nervous System, mainly responsible for a series of finely-controlled motor activities that manipulate food.
The ENS contains neurons just like the brain does and they are arranged in specific ways to facilitate the previously mentioned movements. However, the principles remain the same.
A quick rundown on those principles
Don’t forget about the molecules I told you about before, because the way they start a signal may be disrupted in conditions like Autism.
Such molecules are called Neurotransmitters. They work by binding to receptors on a neuron when released into the synapse. The brain can perform a range of actions through this process. For instance, certain neurotransmitters can bind to a receptor and increase the excitability of that neuron while others can have an opposite, inhibitory effect. All these receptors are there because they are bound to the cell surface by specific proteins.
Neuroligins are a group of proteins doing exactly that. A mutation in Neuroligin-3 has been linked to autistic-like behaviours in mice. At a molecular level, amino acids swap positions in the protein, changing its whole function.
Is Autism simply a result of our complex nature?
Not necessarily. It is absolutely mind-blowing as to how much we have in common with other species.
An “autistic” mouse doesn’t have proper social interactions with other mice and often engages in repetitive activities, just like children on the autism spectrum do. Interestingly, drugs used to reduce aggressive behaviour in some autistic children yield a similar result in mice.
It’s obvious we have tons of information at our fingertips, but what do we make of it? Does Autism start in the gut and travel up to the brain? Or is it the other way around? Current research is wading through such questions in hope for some closure for all of us out there.