Scientists have created a smarter mice, as if they were not already smart enough. Jokes apart, the novel scientific development reported in the latest issue of Nature journal has once again raised crucial questions on ethics of genetic engineering that accompanied the cloning debate. In the latest development, American scientists have produced significantly smarter mice by adding a single gene to rodent embryos, an alteration that resulted in improved performance on a wide range of learning and memory tasks. The researchers say their creation -- named Doogie Mice after Doogie Howser M.D, the TV serial about the student prodigy--has the potential to tackle cognitive disorders in people like old-age related memory loss and Alzheimer's disease.

Critics say the development could also lead to smarter designer pets, not to speak of the even more disturbing idea ofdesigner babies and children, and untold social consequences of such a development.

The lead scientist in the venture acknowledged it as much when he reflected that there will be issues of access to the technology and who can afford it, and whether the socially wealthy class will begin to have intellectual advantage over the poor. ``We are in an era when breakthroughs in biology and intelligence are outpacing the culture's capacity to deal with the ethics,'' Joe Tsien, the Princeton University molecular biologist who led the effort was quoted as saying. But first, the experiment: Researchers inserted into mouse embryos extra copies of a gene that enhances what is known as long-term potentiation, a mechanism involving cognitive skills (like remembering where something is stored or recognising something new in a roomful of familiar objects). The gene, called NMDA receptor 2B or NR2B, is present in all mammals. It directs the production of a nerve protein that helps the brain recognise linkage, for e.g betweenthe ringing of the bell and delivery of food, or the sound of the dog chain and the walk. The NR2B gene normally becomes less active as one grows older (hence forgetfulness, and in extreme case Alzhiemer's). But pumped with extra copies of NR2B, Doogie mice remained extra-smart, and into old age at that. The enhancement also turned out to be permanent and was passed on to Doogie Mice Jrs.

In one of the several experiments a set of mice was subjected to, researchers allowed them to explore two objects for a few minutes. The mice were later placed in a box with one familiar object and one new object. Doogie mice hared to the new object quicker and spent far more time with it (than their non-engineered mates) even three days after the original session. Scientists said this was an indication of better long term memory.

In another test, mice were placed in a tank of milky water and had to learn the location of a platform on which they could rest. Compared to ordinary mice, Doogies were quicker to remember theplatform's location once both groups had found it and were more likely to swim to that part of the tank in subsequent trials. In yet another experiment, mice were administered shocks to the accompaniment of a sound. Ten days later, Doogie mice froze in anticipation of pain quicker when the sound came, compared to their non-engineered mates. While researchers and critics immediately got into a frenzy of speculation about the commercial applications of the development-- engineering smart genes into babies--there were several cautionary voices. One group warned against the idea that intelligence is a purely genetic trait, arguing that it is an extremely complex phenomenon woven from countless social and environmental experiences. Other social scientists said mankind's striving for perfection ``is a seemingly highminded worldview with potentially large psychological and cultural downsides.''