Recent study by researchers associated with Columbia University Medical Center in New York has unearthed the fact that children as well as teenagers suffering from autism have too many synapses in their brain. This can affect the functioning of the brain. Researchers also opine that it will be possible to reduce this excess synapse formation with a drug. This will thus pave way for the first novel way to treat autism.
1 in 68 children in US have Autism – which is a condition which is characterized by behavioral, social and communication problems. It is not clear why Autism is caused but researchers are of the opinion that abnormalities are caused by abnormalities in the structure of the brain which impedes it from working normally.
The latest study was co authored by Guomei Tang, PhD, assistant professor of neurology at Columbia University Medical Center (CUMC) and involved the analysis of 26 brains of children and adolescents with autism who had died from different causes, alongside 22 brains of children without autism.
The brains of those children suffering from autism, 13 were aged between 2-9 years. The remaining of the children were teens between the ages of 13 to 20 years. The synapse density was then assessed by Dr. Tang by counting the tiny spines extending from them. Synapses are where the brain cells connect and communicate with one another. Every spine connects with the brain cell via synapse.
Dr Tang found out that the brains of persons without autism had only 50% spines by late childhood. However the brains of the children with autism showed that their brains still had 84% of their spines intact by late childhood. The brains of children with autism also possessed neurons with old and damaged elements. The neurons also exhibited deficiency in a pathway known as autophagy in which the cells eat up their own damaged parts. This is the reason why most of the spines and the synapses are intact in autistic children.
Senior study investigator Dr. David Sulzer, professor of neurobiology in the Departments of Psychiatry, Neurology and Pharmacology at CUMC, says: “It’s the first time that anyone has looked for, and seen, a lack of pruning during development of children with autism, although lower numbers of synapses in some brain areas have been detected in brains from older patients and in mice with autistic-like behaviors.”
The research team analyzed mouse models of autism and found that lack of pruning of the spines leads to over activity in a protein called mTOR. When there is an excess of this protein, the brain cell face a steep reduction in the self eating functions. Thus too many synapses can impact the brain functions.
The team also tested a new drug –Rapamycin which blocked mTOR activity on the autistic mouse and found that Autophagy was restored in the mice which in turn reduced the synapse formation. This in turn reduced the autistic behavior the mice. A similar approach could be used to treat patients who have been diagnosed with autism.