Existing Drug Reverses a Form of Mental Retardation in Mice

Researchers report that if a study on mice holds true, a drug used for a completely different purpose could be used to treat a kind mental retardation linked to autism.

A medication, used by doctors for patients whose bodies may reject new organs in their bodies due to transplants, is used by scientists learning disorders by the name of tuberous sclerosis complex (TSC) in mice. This disease is a rare genetic disorder that causes tumors, seizures, sores, and learning issues in 50,000 people in the US and 1,000,000 people in the whole world.

Half of everyone with TSC have autism, and 1 in 5 suffer from mental retardation. A neurobiologist, Alcinco Silva, says that the hope is that this medication (rapamycin) can be used to treat learning issues and short-term memory problems in all kinds of autism as well.

Silva and coworkers removed a copy of the gene TSC2 from mice (if both are removed the mice die short after birth) to have them be born with TSC. When both genes are there, in both mice and humans, the make proteins that aid innerve connections that help the brain learn.

The mice with TSC had issues in various learning tests. In the mice "learning and memory are disrupted just like they [are] affected in most patients with TSC," says Silva.

Their reason for using rapamycin, says Silva, is that it regulates the same proteins the TSC gene does, just in different parts of the body. When they tried the medication on animals 3-6 months old (far into adulthood for mice) it leveled the defferences between TSC and regular mice in as short as 3 days.

"What was surprising is that we could give rapamycin to adult mice and reverse their condition," says Silva. "We did not know...that this drug would be equally effective for the learning disabilities" because it is for tissue rejection.

For transplant patients rapamycin cost aroun $1,000 a month. It suppresses the immune system, thus the following side effects come about: impaired wound healing, infections, mouth sores, and skin cancer (rare instances).

SIlva also says that thye have "early, positive signs" from the mice models that rapamycin can help treat kidnye tumors, skin lesions, and the other effects associated with TSC. A director of a TSC Clinic, David Franz, has reported that the medicine reduced kidney and brain tumors in small clinical trials he has conducted.

Scientists were also able to reverse mantal retardation in mice suffering from fragile X syndrome and Rett syndrome. Put together and these results suggest that researchers are finding the brains malfunctions causing autism and thus might find a way to reverse them.

These studies "suggest that we're about to have a paradigm shift in how we look at developmental disorders, like autism," Silva explains.Silve believes these learning disabilities can be eliminated by altering the brain's biochemistry, so the illnesses should no longer be seen as something a person is born with.

Franz agrees that this medication can modify TSC, but thinks that Silva is over-estimating it insaying that it will work for all autism sufferers. Franz says, "You might make them better, but I don't think you're going to normalize them."

At the University of Cambridge in England, the next step, being clinical trials of rapamycin in human TSC sufferers, is already underway.


My Response:

I always thought that mental retardation was permanent and that there was no chance of reversing it. I am glad to say that this article totally changes this thought. This gives new hope to possibly "curing" mental retardation and autism. This research could lead to a way of making the mentally disabled have a possibility of fully living independent lives. This could be a bit of an exageration..but this research and experimentation definately opens a whole new world of possibilities for brain malfunctions and learning diasabilities.


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