Smell

Researchers have learned a lot about how the olfactory nerve cells detect odorants. However, they have not yet learned how this information is coded by the olfactory cell. Other topics of future research will be how olfactory cell signals are processed in the olfactory bulb, and how this information relates to higher brain functions and our awareness of smell.

Scientists are only beginning to understand the role that smell plays in animal, and human, behavior. The vomeronasal sense of animals is still largely not understood. Some researchers have even suggested that the human vomeronasal organ might retain some function, and that humans may have pheromones that play a role in sexual attraction and mating—although this hypothesis is very controversial.

In addition, detailed study of the biology of the olfactory system might yield gains in other fields. For instance, olfactory nerve cells are the only nerve cells that are derived from the central nervous system that can regenerate, possibly because the stress of their exposure to the outside world gives them a limited life span. Some researchers hope that studying regeneration in olfactory nerve cells or even transplanting them elsewhere in the body can lead to treatments for as yet irreversible damage to the spine and brain.