Oxytocin has been the focus of intense research around autism spectrum disorder (ASD) due to the hormone's reported positive effects on anxiety, empathy, social interaction, and maternal behavior. ASD is characterized by early onset of behavioral and cognitive alterations, and by low plasma levels of oxytocin.
The enzyme CD38 was recently demonstrated to be critical to the regulation of oxytocin secretion. An animal study published in The FASEB Journal sought to explore whether a deficit in CD38 expression would lead to functional modifications of the brain's prefrontal cortex, which is involved in social behavior.
To conduct the experiment, researchers collected four groups of mice with an altered CD38 gene: adult male mice, adult female mice, juvenile male mice, and juvenile female mice. The researchers then used MRI technology, as well as electrophysiological and biochemical experiments, to compare the mice to four respective control groups of C57BL/6 mice.
The adult male mice displayed excessive brain growth and neuron dysfunctions that are associated with profound alterations in oxytocin and neurotransmitters involved in social behavior, empathy, and well-being. Both the juvenile and adult female mice, as well as the juvenile male mice, demonstrated normal brain development despite lacking the CD38 gene.
The juvenile and adult female mice also displayed limited alterations to neuron functions. The juvenile male mice, on the other hand, displayed a decrease in vocalization emission rate that preceded the social alterations seen in the adult male mice. This finding suggests that an early decrease in communication ability might signal the emergence of further social alterations in adulthood that could be linked to an oxytocin deficit.
"These findings could be highly relevant for people with ASD and other developmental disorders," said José Manuel Cancela, PhD, a researcher at the Paris-Saclay Institute of Neuroscience, a joint research unit of the National Center for Scientific Research, France (CNRS) and Paris-Sud University. "Further study should consider that some emotional, social, and behavioral difficulties might be in part reversible by pharmacology acting on CD38, oxytocin, or other affected neurotransmitters."
"This hormone, discovered in the context of inducing labor, clearly has a wider job description and this study is a stirring advance on that exciting front," said Thoru Pederson, PhD, Editor-in-Chief of The FASEB Journal.
This research was supported by grants from CNRS, INSERM, and Paris-Sud University. Funding for this work was provided by the Jérôme Lejeune Foundation and an international CNRS grant.
The FASEB Journal is published by the Federation of the American Societies for Experimental Biology (FASEB). The world's most cited biology journal according to the Institute for Scientific Information, it has been recognized by the Special Libraries Association as one of the top 100 most influential biomedical journals of the past century. Receive monthly highlights for The FASEB Journal; subscribe at http://www.
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