UT Southwestern researchers debut “Rain Man” mice

Introduction of mutated neuroligin-3 leads to rodent autism. Who knew?

by John P. Meyer

Here they go again.

Those mice-manipulating mad scientists over at UT Southwestern Medical Center have genetically engineered a strain of rodents (and by "strain" I refer to living, scampering critters) which exhibit characteristics comparable to human autism, and they did it by introducing a mutated human gene implicated in the debilitating condition.

The affected mice ("affected" in the sense that they been effed up royally by the introduction of neuroligin-3 molecules into their wee brains) exhibit the sorts of symptoms one might expect from an autism-disordered human: they have poor social skills, but increased intelligence.

However: "Any model we make will only be an approximation of the human condition," says Dr. Thomas Südhof, senior author of the study and chairman of neuroscience at UT Southwestern.

Effects of autism in humans run the range from severe mental retardation to mild social impairment. In the movie Rain Man, Dustin Hoffman portrayed a man affected by the disorder. Clinicians estimate that about 1.5 million people in the U.S. are in some sense autistic.

The mice altered for the study were exposed to an unknown mouse in a cage; compared to their un-effed-up litter-mates, they spent less time paying attention to the stranger mouse and more messing around with inanimate objects - such as, one presumes, cheese. At the same time, the scientifically jacked-with mice proved more adept than normal at that tried-and-true mouse-testing activity: maze running.

Says Dr. Südhof: "When you manipulate a brain, you usually don’t improve it. The fact that we get an improvement is very good. It shows we’re changing something specific; we’re affecting how the brain processes information.” I get the impression that Doc Südhof knows whereof he speaks when it comes to manipulating brains; as a result he's been expunged from the guest list for my next dinner party.

Bottom line: it turns out that a focus on the inhibiting action of certain nerve cells in the brain may prove to be a means of treating autism disorders.

But they're probably going to need more mice to make sure.