Sequencing Study Reveals Spatial Organization in Olfactory Complex

Using high-throughput sequencing techniques, investigators from Cold Spring Harbor Laboratory have uncovered new details about the structure of the mammalian olfactory complex, the part of the brain responsible for the sense of smell. Unlike other sensory modalities, in which neural connections are organized to reflect relevant stimulus features such as spatial location and sound frequency, no such structural organization has previously been found in the olfactory complex, where connectivity appears random. In a study appearing this week in Cell, the researchers used sequencing-based neuroanatomical techniques to analyze the projections of 5,309 mouse olfactory bulb and 30,433 piriform cortex output neurons at single-cell resolution. Contrary to the prevailing belief, they find that olfactory cortex connectivity is spatially structured in triadic circuit motifs along the anterior-posterior axis of the piriform cortex. "Thus, as in other sensory modalities, olfactory information is routed at early stages of processing to functionally diverse targets in a coordinated manner," they write.