Mice containing a mutated human gene implicated in autism exhibit the poor social skills but increased intelligence akin to the disease, according to researchers at UT Southwestern Medical Center. The researchers’ study also shows how the mutation affects nerve function.
The investigators introduced a mutated human form of the neuroligin-3 molecule into mice. They studied the patterns of electrical activity in the brain. An imbalance in the normal pattern is thought to be involved in autism, they explain.
Nerve cells from the genetically engineered mice showed a significantly greater inhibitory action than their normal littermates, even though only about 10% of the normal amount of neuroligin-3 was present. This finding was a surprise, as other studies have indicated that a loss of inhibitory action might be involved in autism spectrum disorders, according to the investigators.
The research team also reports that the genetically engineered animals did mirror autism in people. They tested their social interactions by exposing them to an unknown mouse in a cage. The mice spent less time near the strange mouse than their normal littermates and preferred to spend time with inanimate objects. The mice also were significantly better than normal at learning tasks, mirroring autism in people.
The study appears online in Science Express and will be published later in Science.