A recent study published in Cell revealed how approximately 1,100 olfactory receptors expressed on sensory neurons are ordered in strictly regulated spatial positions in the epithelial tissue lining the nasal cavity. Another study published at the same time produced a complementary map of the expression of olfactory receptors in the olfactory epithelium and their neural connections to the brain's olfactory bulb.
This is the world's first spatial distribution map of olfactory receptors. This achievement completely subverts the 30-year-old olfactory perception and is called a milestone breakthrough in the industry.
Through single-cell sequencing and spatial transcriptomics, the scientific research team analyzed approximately 5 million neurons in hundreds of mice, successfully mapped the precise distribution of approximately 1,100 olfactory receptors in the nasal cavity, and simultaneously revealed their neural connection patterns with the olfactory bulbs of the brain.
Previously, academic circles generally believed that olfactory receptors are randomly distributed in the nasal cavity; but the new map confirms that each receptor occupies a fixed position and extends from the top to the bottom of the nasal cavity in the form of horizontal stripes. Different stripes intersect with each other to form a highly ordered topological structure.
The study also found that the gradient distribution of retinoic acid is a key factor in regulating receptor positioning, and the development process is strictly controlled by genes.
This map corresponds one-to-one with the processing mode of the brain's olfactory bulb, indicating that the nasal cavity and the brain follow the same set of development logic, making the olfactory system, like vision, hearing, and touch, have a clear spatial mapping relationship.
This discovery overturns the traditional textbook model and provides a core theoretical basis for stem cell repair treatment of smell loss - only stem cell transplantation covering the entire nasal cavity can completely restore olfactory function.
Currently, the research team is promoting human tissue verification and trying to establish the correspondence between odor and receptor stripes. It is expected to be used in many fields such as disease diagnosis and intelligent sensing in the future.