Recent Research and News
New NIDCD Research Offers Intriguing Clues About the Role of Smell in Food Preference
Two mice exploring their lunch option.
Scientists have noticed for decades that rodents take their dining clues from their peers, basing their preferences for different foods on the last thing one of their buddies ate. It’s a behavioral strategy that could be seen as a way to stack the deck against eating harmful or poisonous foods. Earlier studies had shown that it was the odor of carbon disulfide (a byproduct of food metabolism) on the breath of the other mouse or rat, combined with the scent of bits of food clinging to their fur and whiskers, which acted as a social cue. But no one had been able to explain how the brain put the two odors together to signal “okay to eat.” NIDCD-funded researcher Steven Munger, Ph.D., at the University of Maryland School of Medicine, along with an international team of researchers, used knock-out mice to show that the behavior is the result of a dedicated subsystem of specialized olfactory receptors in the nose and neural circuits in the brain. This subsystem involves a small family of olfactory receptors called the GC-D+ neurons that send signals to the necklace glomeruli, specialized clusters of neurons in the olfactory bulb that act as a way station for signals as they move from the nose to the brain. Unlike most glomeruli, the necklace glomeruli integrate multiple sensory inputs, which allow them to pair the two odors and alert the olfactory brain. The finding offers clues for humans about how we learn to associate behavior with odor. Read more on the NIDCD website. The study is published in Current Biology. An abstract of the study is available on Pub Med.