These mice are different from regular mice because they have been genetically engineered to have more than the usual amount of part of a protein called the NMDA receptor. According to Tsien, this receptor strengthens the connection between two active neurons. This may help learning and memory.

These mice are not as smart as humans, but they can remember things better than regular mice. The genetic difference in the protein in these mice keeps the NMDA receptor open twice as long. This is what improves their memory.

How do you genetically engineer a mouse? You isolate a fertilized mouse egg cell and inject it with the special gene. This egg is then implanted in a female mouse. Only some of the eggs that are altered this way will produce Doogie mice.

There are no immediate plans for genetically engineering smart humans. Tsien hopes that the research will help pharmaceutical companies develop drugs that can help memory. This might someday help people with Alzheimer’s.

What can these smart mice do? They can navigate mazes very easily and remember which corner is a dead end. These mice have also navigated a bowl of murky water where there is an invisible Plexiglas platform that they can use to crawl out of the water. Mice hate to get wet. The Doogie mice were able to remember the location of the Plexiglas platform better than regular mice. So Doogie mice cannot secretly drug cats or build elevators like the rodents in Mrs. Frisby and the Rats of NIMH, but they can do some remarkable things!

Princeton University Web Site
Scientific American Article on Smart Mice