In retrospect: Flowers for Algernon
Ananyo Bhattacharya looks back at a science-fiction touchstone on the ethics of experimental biology.
Fat rats skew research results
Failure to recognize that many laboratory animals live unhealthy lives may be leading researchers to misinterpret their findings, potentially misdirecting efforts to develop theraputic drugs. The problem, reports a group at the US National Institute on Aging in Bethesda, Maryland, is that many rats and mice used in experiments are so overweight that they are glucose intolerant and heading for an early death (B. Martin et al. Proc. Natl Acad. Sci. USA doi:10.1073/pnas.0912955107; 2010). As a result, data from the animals — about, for example, the effects of an anti-cancer drug — may not apply to normal-weight animals. “The vast majority of investigators who use rats and mice don’t recognize that their normal conditions are relatively unhealthy,” says Mark Mattson, chief of the National Institute on Aging’s Laboratory of Neurosciences and a co-author on the paper. “The most logical way to extrapolate is to say any data we obtain in the animal model would be more relevant to overweight, sedentary humans than normalweight, active individuals.” Mattson and his colleagues note that the standard lab practice of allowing rats and mice continuous access to food without much opportunity to exercise can cause some to balloon in weight to up to 1 kilogram. Beneficial effects of a potential drug or behaviour could simply result from its effect on the consequences of an animal’s unhealthy lifestyle, they say, and studies showing that caloric restriction can extend lifespan may have to be reinterpreted. “A major reason the lifespan of rats and mice is extended by caloric restriction is they started from an unhealthy baseline,” argues Mattson. He and his co-workers identify areas as diverse as immune function, cancer and neurological disorders that could be affected by the problem. Mattson says that including running wheels in cages and feeding only on alternate days could solve the ‘fat rat’ problem, adding that the institutional committees that oversee and approve such experiments should encourage researchers to tackle the problem. The fat-rat hypothesis is certainly credible, says Robin Franklin, a neuroscientist and director of research at the Department of Veterinary Medicine , University of Cambridge, UK. “But I suspect it’s one of many factors that are responsible for the difference between animal models and human diseases,” he says, adding that the problem has not been apparent in his research. Still, Mattson and his colleagues have penned “hundreds of papers using rodent models and are widely known in their field”, says Christian Newcomer, executive director of the Association for Assessment and Accreditation of Laboratory Animal Care, a non-profit organization based in Frederick, Maryland, that accredits animal use in many laboratories, including those of the US National Institutes of Health. “I think [the paper] is going to carry a lot of weight.” ■ Daniel Cressey Fat rats skew research results IS TO C KP H O TO
Technology: Use or lose our navigation skills
GENDER Institutional changes are necessary to gain equality p.579 PSYCHOLOGY How we view the passage of time affects our decisions p.577 MATHEMATICS Biopic charts the challenges faced by Indian maths giant Ramanujan p.576 Use or lose our navigation skills Automatic wayfinding is eroding natural abilities, warns Roger McKinlay. I n 1984, I was part of a team that was developing a receiver for a satellite-navigation system. After weeks of debugging, the blur of random digits settled on a location. We grabbed a map and plotted the point. The pencilled cross landed exactly on the building that we were in. More than 30 years later, the amazement that I felt still remains. The technology we use is the same — just smaller. But our dependence on knowing exactly where we are has changed. Navigation has invaded our dreams of the future. Fleets of driverless cars will transport us around cities. As you are driven past the shop that you viewed online, the mannequin wearing the dress that you clicked on will wave and call your name. Or you could stay at home and let a drone deliver your goods. This is the vision with which innovative companies such as Google and Amazon tempt us. The days of being lost should be over. Access to satellite navigation is ubiquitous, and 80% of the adult population worldwide is likely to own a smartphone by 2020. But it is still not easy for people or machines to find their way around. Satellite navigation is unreliable because it does not work well indoors or in built-up areas. When your phone tells you where you are in a shopping centre, for example, it will actually be a guess based on ground-based WiFi networks. That is because signals from satellites are weak (similar to viewing a 20-watt light bulb from almost 20,000 kilometres away), prone to error and easily disrupted. More satellites are being launched to improve coverage. By 2020, 30 orbiters from Galileo, the European satellite-navigation system , will complement the US Global Positioning System (GPS) and the Russian GLONASS network. China has just launched the twenty-first satellite in its BeiDou system. Successful navigation indoors will need other solutions, such as a combination of wall-mounted antennas and WiFi. Quantum physics could come to the rescue. Although the technology is still in its infancy and will take more than a decade to develop, small and super-sensitive quantum …