Visualizing an Olfactory Sensory Map

TLDR

Neurons expressing a specific receptor project to only two topographically fixed loci among the 1800 glomeruli in the mouse olfactory bulb. The study aims to develop a genetic approach that can be broadly applied to visualize the development and plasticity of projections in the mammalian nervous system. We have developed a genetic approach to visualize axons from olfactory sensory neurons expressing a given odorant receptor as they project to the olfactory bulb, and this approach may be broadly applied to study development and plasticity of projections in the mammalian nervous system. Our data support a model in which a topographic map of receptor activation encodes odor quality in the olfactory bulb, and receptor swap experiments show that the receptor instructs guidance but is not the sole determinant of map establishment.

Abstract

We have developed a genetic approach to visualize axons from olfactory sensory neurons expressing a given odorant receptor, as they project to the olfactory bulb. Neurons expressing a specific receptor project to only two topographically fixed loci among the 1800 glomeruli in the mouse olfactory bulb. Our data provide direct support for a model in which a topographic map of receptor activation encodes odor quality in the olfactory bulb. Receptor swap experiments suggest that the olfactory receptor plays an instructive role in the guidance process but cannot be the sole determinant in the establishment of this map. This genetic approach may be more broadly applied to visualize the development and plasticity of projections in the mammalian nervous system.