The brain changes the way it works when you get a stuffed nose due to a cold. Researchers say that it does this to protect your sense of smell.
"You need ongoing sensory input in order for your brain to update smell information. When your nostrils are blocked up, your brain tries to adjust to the lack of information so the system doesn't break down. The brain compensates for the lack of information so when you get your sense of smell back, it will be in good working order," said Keng Nei Wu, a graduate student in neuroscience at Northwestern University Feinberg School of Medicine and lead author of the paper.
For the study, 14 participants were asked to stay in a special low-odor hospital room for a week. Researchers found that smell deprivation led to changes in certain areas of the brain. There was an increase in activity in the orbital frontal cortex and decrease in the activity in the piriform cortex. Both the areas are known to be associated with the sense of smell.
When participants returned to normal smelling, activity in the brain areas changed again. Within a week after the hospital stay, their brain regions resumed normal activity.
"These changes in the brain are instrumental in maintaining the way we smell things even after seven days of no smell," Wu said.
Researchers said that the regions dedicated to smell are more agile unlike other senses like sight that take longer to return to normal.
Wu said that the study had clinical significance in knowing how the brain activity in people with chronic sinusitis changes over time.
"It also implies that deprivation has a significant impact on the brain, rather than on the nose itself. More knowledge about how the system reacts to short-term deprivation may provide new insights into how to deal with this problem in a chronic context," Wu said.