Study Seeks to Explain How Smell is Impacted in Individuals with Autism

Newswise — A new study by a researcher at New York Institute of Technology College of Osteopathic Medicine (NYITCOM) could help explain how the sense of smell is impacted in individuals with autism.

Individuals with autism have an “insistence on sameness,” and often avoid unfamiliar elements, including new smells and foods, which can impact their quality of life. While many studies have focused on the behavioral features of autism, additional research is needed to help explain its sensory aspects.

Now, research published in The Journal of Neuroscience, authored by NYITCOM Assistant Professor of Biomedical Sciences Gonzalo Otazu, Ph.D., analyzes a mouse model of autism and reports differences in the neurological processes responsible for smell.

The findings reinforce one of Otazu's earlier studies, which was published in the journal Nature Communications in February. In this earlier study, his team trained two groups of mice—one group with a mutation in a gene linked to autism (CNTNAP2 knockout mice) and one neurotypical group (wild-type mice)—to recognize familiar scents. Both groups succeeded in doing so. Then, they were tasked with identifying these scents when new, unfamiliar odors were introduced in the background. While the neurotypical mice were able to “filter out” new background odors and identify target scents, the CNTNAP2 knockout mice struggled to do so.

In this latest study, Otazu repeated a similar process in mice with a mutation in the SHANK3 gene, a leading autism candidate gene, and found that the same deficit appeared in this mouse model. 

Otazu and his co-authors write: 

"People and mice with mutations in a single copy in the synaptic gene SHANK3 show features seen in autism spectrum disorders, including social interaction deficits...Here we used a recently developed task to show that these mice could identify odors in the presence of known background odors as well as wild-type mice. However, their performance fell below wild-type mice when challenged with novel background odors. This deficit was also previously reported in the CNTNAP2 mouse model of autism suggesting that odor detection in novel backgrounds is a general deficit across mouse models of autism."