51% of COVID-19 patients report they experienced the loss of smell and taste up to five months after infection. On average, once their senses were restored, people reported a loss in sensitivity to smell and taste.
Regions of the olfactory system in mice with higher amyloid beta expression exhibited lower activation of olfactory sensory neurons and decreased odor detection.
Researchers discovered unique connectivity between the hippocampus and olfactory areas in the brain, a finding which explains why specific odors can trigger powerful memories. The study also reports a loss of sense of smell is associated with depression and a poorer quality of life.
Olfactory imprinting in infant mice has a direct impact on their social behaviors as adults.
People with a poor sense of smell are 50% more likely to be hospitalized for pneumonia than those with a good sense of smell.
Following injury or damage, insulin plays a key role in the maturation and regeneration of immature olfactory sensory neurons.
Women with postpartum depression report normal olfactory sensitivity, while those who are genetically predisposed to major depressive disorder have decreased olfactory sensitivity.
The habenula relays external information, such as sight and smell, along with internal states associated with emotion and learning to brain regions that govern adaptive behaviors.