An olfactory sensory neuron line, Odora, properly targets olfactory proteins and responds to odorants

The site for interactions between the nervous system and much of the chemic al world is in the olfactory sensory neuron (OSN). Odorant receptor protein s (ORPs) are postulated to mediate these interactions. However, the functio n of most ORPs has not been demonstrated in vivo or in vitro. For this and other reasons, we created a conditionally immortalized cell line derived fr om the OSN lineage, which we term odora. Odora cells, under control conditi ons, are phenotypically similar to the OSN progenitor, the globose basal ce ll. After differentiation, odora cells more closely resemble OSNs. Differen tiated odora cells express neuronal and olfactory markers, including compon ents of the olfactory signal transduction pathway. Unlike other cell lines, they also efficiently target exogenous ORPs to their surface. Strikingly, differentiated odora cells expressing ORPs respond to odorants, as measured by an influx of calcium. In particular, cells expressing one ORP demonstra te a specific response to only one type of tested odorant. Odora cells, the refore, are ideal models to examine the genesis and function of olfactory s ensory neurons.