The way in which mice sniff out scent of food on the breath of their fellow mice to decide whether it's safe to eat or not has been shown by researchers.
Researchers at the University of Maryland School of Medicine in Baltimore knew how mice pair a particular odour with a chemical ingredient found in mouse breath.
And now they know how mice manage to sniff that connection out.
"It's as if the mouse were thinking something like, 'My buddy ate food that smelled just like what I have in front of me. He isn't dead. Therefore, this food must be safe to eat,'" explained Steven Munger.
"We found that a small subdivision of the olfactory system-one that differs from the rest of the olfactory system in the expression of key proteins used to translate a chemical stimulus into neural signals and in the way it connects to the brain-is specialized for detecting this social stimulus.
"When function of this olfactory subsystem is disrupted, mice can no longer make sense of this social signal, and thus they fail to make a positive judgment about the food. We now have an answer to the question of how mice can communicate complex information just by breathing on each other," added Munger.
The discovery about this portion of the olfactory system, known as the GC-D necklace subsystem, adds to growing evidence that the sense of smell is in fact made up of many parts, each with a very specialized purpose.
The researchers' studies showed that the GC-D necklace subsystem responds to carbon disulfide, a chemical ingredient in rodent breath and that mice unable to detect that component of rodent breath failed to adjust their food selections after interacting with a "demonstrator" mouse that had just eaten chow seasoned with either cinnamon or cocoa.
The study has been published in Current Biology, a Cell Press publication.