FLICKR, SARAH LAVALMice carrying a mutation known to cause fragile-X syndrome in children and rats exposed in utero to sodium valproate, an epilepsy drug linked to autism in the children of women who had taken the medication, exhibit higher-than-normal levels of chloride in the hippocampus. Moreover, neurons in this brain region were excited by the neurotransmitter GABA, rather than inhibited by it—a phenotype that has been associated with autism in humans and other animal models. But when pregnant mice and rats were given bumetanide, a common diuretic medication known to reduce chloride levels in cells, the day before giving birth, these problems were reversed, and the pups displayed fewer autistic-like behaviors, according to a study published this week (February 6) in Science.
The offspring of treated mothers “have more GABA, low chloride, [and] fewer behavioral problems,” neuroscientist Yehezkel Ben-Ari at the Mediterranean Institute of Neurobiology in Marseille told Nature.
The results give weight to a previous clinical study conducted by Ben-Ari and colleagues, in which children with less severe forms of autism seemed to benefit from daily treatments with bumetanide.
Whether the results will translate to humans remains to be seen, of course, especially as rodents are more developed at birth than humans. “This paper is not telling us ‘Okay, we’ve got the treatment for autism,’” Elizabeth Berry-Kravis, a pediatric neurologist at Rush University Medical Center in Chicago, Illinois, told Nature. “Until we roll out a big trial in humans we aren’t going to know whether it’s possible to treat humans later on, when they have a diagnosis.”
Just such a trial is ongoing in Europe, funded by Marseille-based Neurochlore, where Ben-Ari is the chief executive.