A little bit of learned fear is a good thing, keeping us from making risky, stupid decisions or falling over and over again into the same trap. But new research from neuroscientists and molecular biologists at USC shows that a missing brain protein may be the culprit in cases of severe over-worry, where the fear perseveres even when there's nothing of which to be afraid.
In a study appearing the week of July 15 in the Proceedings of the National Academy of Sciences, the researchers examined mice without the enzymes monoamine oxidase A and B (MAO A/B), which sit next to each other in our genetic code as well as on that of mice. Prior research has found an association between deficiencies of these enzymes in humans and developmental disabilities along the autism spectrum such as clinical perseverance the inability to change or modulate actions along with social context.
"These mice may serve as an interesting model to develop interventions to these neuropsychiatric disorders," said senior author Jean C. Shih, USC University Professor and Boyd & Elsie Welin Professor of Pharmacology and Pharmaceutical Sciences at the USC School of Pharmacy and the Keck School of Medicine of USC. "The severity of the changes in the MAO A/B knockout mice compared to MAO A knockout mice supports the idea that the severity of autistic-like features may be correlated to the amounts of monoamine levels, particularly at early developmental stages."
Shih is a world leader in understanding the neurobiological and biochemical mechanisms behind such behaviors as aggression and anxiety. In this latest study, Shih and her co-investigators including lead author Chanpreet Singh, who was a doctoral student at USC at the time of the research and is now at CalTech, and Richard Thompson, USC University Professor Emeritus and Keck Professor of Psychology and Biological Sciences at the USC Dornsife College of Letters, Arts and Sciences expand their past research on
|Contact: Suzanne Wu|
University of Southern California