Studying the biology of autism spectrum disorder has been difficult for researchers: rats and mice are not reliable models for the condition. But when scientists turned to monkeys, they found a species that can be an effective stand-in for people. In a paper published in Science Translational Medicine, researchers may have found a hormone that signposts autism by studying rhesus macaque monkeys.
Advertisement – Continue Reading Below
For the study, researchers found 15 male rhesus macaques that weren’t interested in playing, grooming or socializing with their fellow monkeys, and compared them with 15 high social animals. Scientists analyzed the two groups, looking for differences in biological markers that had been previously identified as potential links to autism.
They discovered that low concentrations of a molecule called arginine vasopressin (AVP) in the cerebrospinal fluid corresponded to autism like social behavior in monkeys, while higher AVP concentrations corresponded to more social animals. When they compared the results to the AVP concentrations in a sample of boys, they found similar results. Their human sample size was, however, quite small: spinal fluid requires a lumbar tap to collect, which meant they relied on samples that had already been collected from boys for medical reasons, and only had 14 samples to rely on.
If vasopressin can be strongly linked to autism, it could be used to diagnose the condition earlier, gauge the effectiveness of treatment, or even become a direct drug target. Researchers have viewed vasopressin as a key influence on social function for decades, especially in males, and it could help explain why the condition is so much more common in males than females. (Previously, in monkeys and autism, scientists in China genetically engineered monkeys to display autism-like characteristics in order to investigate treatments and cures.)