Smoking alters brain, says study Smoking causes long-term changes in the brain associated with addiction similar to those in animals given cocaine and heroin, according to a US National Institute on Drug Abuse study. Previous studies have suggested that nicotine is at least as addictive as heroin, but this study indicates that the changes in the brain's neurons may account for the addiction, Reuters reports. Smokers (and even former smokers) had high levels of enzymes that help brain cells use chemical signals such as those made by message-carrying compounds called dopamine. Researchers say it's clear that the drugs cause the change. Telly shrinks kids' melatonin Watching television may harm children far more than has been thought, with a British study suggesting it can increase the risks of permanent eyesight damage, obesity, premature puberty, autism and Alzheimer's disease. The study by psychologist Aric Sigman found that television inhibits the production of melatonin, which affects the immune system, sleep cycle and onset of puberty. Along with lower weight levels, reduced melatonin may help explain why girls reach puberty much earlier than during the 1950s, AFP reports. Lower melatonin may also make it more likely that cell DNA will produce cancer-causing mutations. Video games hone surgical skills On the other hand, playing video games appears to help doctors who perform keyhole surgery requiring precise technique and excellent hand-eye co-ordination. A study of surgeons from Beth Israel Medical Centre in New York found a strong correlation between video-game skills and the ability to perform laparoscopic surgery. Those who had at some stage played video games at least three hours per week made 37 per cent fewer errors, performed 27 per cent faster, and scored 42 per cent better than those who had never played, Reuters reports. But researcher Douglas Gentile of Iowa State University warns: 'Spending that much time playing video games is not going to help a child's chances of getting into medical school.' Collagen link to wrinkle treatment A popular wrinkle-busting cosmetic treatment may actually make the skin produce more collagen - a natural substance that makes skin look young - according to a University of Michigan study that wasn't funded by the manufacturer. Team leader John Voorhees says the maker of Restylane, which is typically injected around the lips, cheeks and foreheads, doesn't appear to be aware that the filler also forces the body to make its own collagen. Restylane's plumping action stretches the fibroblasts (skin cells that make collagen), and prompts them to make more, Reuters reports. The study didn't test rival fillers that also use hyaluronic acid. The researchers want to find out what causes the changes, in the hope of learning how to regenerate other types of cells. Jason Sankey is a tennis professional
