Olfaction results from the proper development and interaction of the two components of the primary olfactory pathway: the olfactory epithelium and the olfactory bulb.
The olfactory epithelium contains olfactory sensory neurons, whose axons innervate the olfactory bulb.
In order for olfactory sensory neurons to function properly, they must express odorant receptors and the proper transduction proteins on non-motile cilia that extend from the dendritic knob in addition to projecting their axons to the olfactory bulb.

The cells of the olfactory epithelium, including olfactory sensory neurons, begin to differentiate soon after the induction of the olfactory placode.
Once the olfactory sensory neurons differentiate, they express odorant receptors, which transduce odorant information from the environment to the central nervous system and aids in the development of the odorant map.
The differentiated olfactory sensory neurons extend pioneering axons, which follow guidance cues released by the underlying mesenchyme, as well as other chemotrophic cues released from the telencephalon.
As development of the olfactory pathway progresses, more axons innervate the olfactory bulb, which develops from the rostral-most region of telencephalon.
The organization and subsequent processing of odorant information is possible due to the convergence of olfactory sensory neuron axons expressing the same odorant receptors onto the same glomerulus at the olfactory bulb.
Olfaction results from the proper development and interaction of the two components of the primary olfactory pathway: the olfactory epithelium and the olfactory bulb. The olfactory epithelium contains olfactory sensory neurons, whose axons innervate the olfactory bulb. In order for olfactory sensory neurons to function properly, they must express odorant receptors and the proper transduction proteins on non-motile cilia that extend from the dendritic knob in addition to projecting their axons to the olfactory bulb.
The cells of the olfactory epithelium, including olfactory sensory neurons, begin to differentiate soon after the induction of the olfactory placode. Once the olfactory sensory neurons differentiate, they express odorant receptors, which transduce odorant information from the environment to the central nervous system and aids in the development of the odorant map. The differentiated olfactory sensory neurons extend pioneering axons, which follow guidance cues released by the underlying mesenchyme, as well as other chemotrophic cues released from the telencephalon. As development of the olfactory pathway progresses, more axons innervate the olfactory bulb, which develops from the rostral-most region of telencephalon. The organization and subsequent processing of odorant information is possible due to the convergence of olfactory sensory neuron axons expressing the same odorant receptors onto the same glomerulus at the olfactory bulb.
Olfactory epithelium