The inner dynamics of a person's nose can be likened to a household, with separate teams doing their own separate tasks. Nasal molecules that respond to pleasant smells hold a different location from molecules that respond to unpleasant smells. This was the result of a study that aimed to test the hypothesis that "the organization of the olfactory epithelium reflects olfactory perception."

Sensor molecules or receptors appear to be organized according to the pleasantness or unpleasantness of the odors they sense. The study, conducted by Noam Sobel of the Weizmann Institute of Science in Rehovot, Israel and his colleagues, was published in the Nature Neuroscience Web site on Sept. 25.

This means that surfaces in the nose that respond strongly to one fragrant smell will also respond strongly to other nice smells. On the other hand, locations in the nose that process undesirable smells will also handle specific types of smells and leave the handling of other smells to other receptors.

The research method involved the insertion of electrodes in the noses of 16 subjects. The volunteers were given six different scents to smell. Because different odors solicited stronger responses from different areas of the nose, the research team was able to confirm previous data that suggested a "variegated nasal receptor surface," said a Science News report.

"We're not the first to find that," says Sobel.

But he and his colleagues have added a new important finding. "Not only are the receptors organized in patches, but the axis that best describes their organization is pleasantness."

This new data adds to what little science has discovered about the nose. Compared with other sensory organs, such as the eyes or ears, scientists are said to know little of how the nose works.

It's interesting to see that the perceptual space would reflect itself on the peripheral level," says Mats Olsson of the Human Olfaction Research Group at the Karolinska Institute in Stockholm, who was not involved in the study.

Even more interesting, these results "may reflect an inherent pleasantness preference system" in the nose, he says.

This natural "attraction to sugary smells and repulsion to acid odors" may give newborn babies the advantage of knowing how to search for sources of food they need for survival, says the report.

It adds that this initial attraction may just be the tip of the iceberg. "The human olfactory system is extremely flexible, able to be remapped according to learning experiences. Without this adaptive component, people might never have developed a taste for foul-smelling foods like limburger cheese, which don't necessarily satisfy essential nutritional needs but sate certain cravings," remarks the Science News report.

A potential result of this research is a clearer physical map of nasal receptors, says Sobel. With this scientists can focus on the areas that respond to unpleasant smells. It may even be possible to block odors from binding on the receptor level. This could practically mean increasing people's ability to avoid offensive smells altogether, and creating products that remove, not just mask, unpleasant scents.