Mice that “smell” light bring new notions to nose research

Harvard University neurobiologists have created mice that can “smell” light, providing a potent new tool that could help researchers better understand the neural basis of olfaction.

The research, described in the journal Nature Neuroscience, employs novel techniques to study the olfactory system — a complex perceptual system that does not lend itself easily to study by traditional methods.

“It makes intuitive sense to use odours to study smell,” said Venkatesh N. Murthy, a professor of molecular and cellular biology at Harvard. “However, odours are so chemically complex that it is extremely difficult to isolate the neural circuits underlying smell that way.”

Instead, Murthy and his colleagues used optogenetic techniques to tease apart how the brain perceives odours. Optogenetic methods integrate light-reactive proteins into systems that usually sense inputs other than light. The researchers then integrated these proteins, called channelrhodopsins, into the olfactory systems of mice, creating animals whose smell pathways were activated not by odours, but by light instead. This allowed the researchers to trace patterns of activation in the mouse’s brain when the olfactory system was triggered by an odour.

The researchers found that the spatial organization of olfactory information in the brain does not fully explain our ability to sense odours. The temporal organization of olfactory information also plays an important role. In other words, the timing of the “sniff” significantly determines how we perceive odours.— Kelly Robertson-Reinhart

Source: Science Daily

Interactive gaming causes broad range of injuries. Better keep that Wii Fit in check!

A study presented at the American Academy of Pediatrics National Conference and Exhibition in San Francisco examined injuries caused by traditional and interactive video games.

Using data from the National Electronic Injury Surveillance System, the study found that injuries to the shoulder, ankle, and foot were more common among those who engaged in interactive video games, compared to players of traditional ones. There was also a higher incidence of injuries to bystanders of the interactive games.

However, of the total 696 injuries reported, only 92 were due to interactive games, and the rest were from traditional video games. Males made up 53 per cent of those injured by interactive gaming, and females constituted the remaining 47 per cent. The study looked at injuries reported over five years, starting in January 2004. Those with reported injuries varied in age from less than one year old to over eighty, with an average age of 16.5 years. — Kimberly Shek

Source: Science Daily

Anxiety is contagious — and it’s all in your sweat

Researchers from the University of Munich have demonstrated that the sweat of an anxious person can make you take more risks. Sweat contains specific chemical signals, which are released when people are anxious. These signals are detected subconsciously, and can influence the behaviour of other people at a close range.

The findings were published by Katrin Haegler and her team in this November’s issue of Neuropsychologia. The researchers collected sweat from people completing high-rope obstacle courses. They then exposed participants to the sweat samples as they played a gambling game.

The study showed that when participants were exposed to the anxiety-laced sweat, they were more likely to bet on high-risk scenarios in the gambling task, compared to when they were exposed to anxiety-free sweat. The conclusions? It seems that anxiety is transmissible to other humans through the chemical senses, which could be an adaptive mechanism to alert others about potential danger in the environment. If those dangers involve exams, however, it may be best to take pity on your library neighbours, and just take a shower. — Erene Stergiopoulos

Source: British Psychological Society Research Digest