Olfactory receptor neuron (ORN (or OSN))

Olfactory receptor neurons are bipolar sensory cells located in the olfactory epithelium of vertebrates. Their dendrites extend into the nasal cavity, while their axons transmit signals through the cribriform plate to the olfactory bulb. Each neuron expresses a single olfactory receptor gene—one protein per cell from a large gene family (>1000 genes)—which enables the detection of specific odorant molecules. Binding of odorants to the receptor triggers a cascade involving G-protein–coupled signaling, cyclic AMP, and the opening of ion channels, resulting in depolarization and action potential generation. Olfactory neurons display fast adaptation via calcium/calmodulin feedback. Their loss or malfunction is linked to impaired smell and is a feature in several neurodegenerative diseases.

Other names

olfactory sensory neuronOSNORNolfactory nerve cell

Not applicable for the cell type as a whole. Drugs affecting olfactory function may act by: Modulating ion channels; Altering GPCR activity; Affecting neurotransmitter release