Agent Reduces Autism-Like Behaviors in Mice Boosts Sociability, Quells Repetitiveness
National Institutes of Health researchers have reversed behaviors in mice resembling two of the three core symptoms of autism spectrum disorders (ASD) using an experimental compound, called GRN-529. GRN-529 increased social interactions and lessened repetitive self-grooming behavior in a strain of mice that normally display such autism-like behaviors. GRN-529 is a member of a class of agents that inhibit activity of a subtype of receptor protein on brain cells for the chemical messenger glutamate, which are being tested in patients with an autism-related syndrome. Although mouse brain findings often don’t translate to humans, the fact that these compounds are already in clinical trials for an overlapping condition strengthens the case for relevance.
The study was reported online in the journal Science Translational Medicine (April 25 2012).
The study followed-up on clues from earlier findings hinting that inhibitors of the receptor, called mGluR5, might reduce ASD symptoms. This class of agents – compounds similar to GRN-529, used in the mouse study – are in clinical trials for patients with the most common form of inherited intellectual and developmental disabilities, Fragile X syndrome, about one third of whom also meet criteria for ASDs. To test their concept, the authors examined effects of GRN-529 in a naturally occurring inbred strain of mice that normally display autism-relevant behaviors. Like children with ASDs, these BTBR mice interact and communicate relatively less with each other and engage in repetitive behaviors – most typically, spending an inordinate amount of time grooming themselves. The authors found that BTBR mice injected with GRN-529 showed reduced levels of repetitive self-grooming and spent more time around — and sniffing nose-to-nose with — a strange mouse. Moreover, GRN-529 almost completely stopped repetitive jumping in another strain of mice.