Olfactory receptor neuron



Olfactory receptor neuron
Labels in German. "Zellen" = "cell","riech" = "smell", "Riechnerv" = olfactory nerve, "cillien" = cilia.
Location olfactory epithelium in the nose
Function Detect traces of chemicals in inhaled air (sense of smell)
Neurotransmitter Glutamate
Morphology Bipolar sensory receptor
Presynaptic connections None
Postsynaptic connections Olfactory bulb
Gray's subject #223 996
 

An olfactory receptor neuron, also called an olfactory sensory neuron, is the primary transduction cell in the olfactory system.

In vertebrates

Humans have about 40 million olfactory receptor neurons. In vertebrates, olfactory receptor neurons reside on the olfactory bulb.

Structure

Many tiny hair-like cilia protrude from the olfactory receptor cell's dendrite into the mucus covering the surface of the olfactory epithelium. The surface of these cilia is covered with olfactory bulb.

Function

A given olfactory receptor can bind to a variety of odor molecules with varying affinities. The activated olfactory receptor in turn activates the intracellular G-protein GOLF (GNAL), and action potential.

Regeneration

Individual olfactory receptor neurons are replaced approximately every 40 days by neural stem cells residing in the olfactory epithelium. The regeneration of olfactory receptor cells, as one of the only few instances of adult neurogenesis in the central nervous system, has raised considerable interest in dissecting the pathways for neural development and differentiation in adult organisms.

In insects

In insects, olfactory receptor neurons typically reside on the antenna. Much like in vertebrates, axons from the sensory neurons converge into glomeruli in the antennal lobe.

See also

v • d • e
Sensory system: Mitral cells • Piriform cortex
Rhinencephalon • Olfactory tract • Olfactory trigone
v • d • e
Histology: nervous tissue
Neurons (gray matter)soma, axon (axon hillock, axoplasm, axolemma, neurofibril/neurofilament), dendrite (Nissl body, dendritic spine, apical dendrite, basal dendrite)
types (bipolar, pseudounipolar, multipolar, pyramidal, Purkinje, granule)
Afferent nerve/Sensory nerve/Sensory neuronGSA, GVA, SSA, SVA, fibers (Ia, Ib or Golgi, II or Aβ, III or Aδ or fast pain, IV or C or slow pain)
Efferent nerve/Motor nerve/Motor neuronGSE, GVE, SVE, Upper motor neuron, Lower motor neuron (α motorneuron, γ motorneuron)
nodes of Ranvier, internode, Schmidt-Lanterman incisures, neurolemma
Related connective tissuesepineurium, perineurium, endoneurium, nerve fascicle, meninges
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Olfactory_receptor_neuron". A list of authors is available in Wikipedia.