AJP - Cell Physiology, Vol 257, Issue 6 C1043-C1054, Copyright © 1989 by American Physiological Society
Molecular physiology of olfaction
R. R. Anholt
Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710.
Olfactory reception is mediated by olfactory receptor cells located in the
olfactory epithelium. These cells are bipolar neurons that extend a
dendrite toward the nasal lumen and an axon toward the olfactory bulb in
the brain. The dendrite possesses a group of apical cilia embedded in
mucus. Odorant recognition and signal transduction are initiated at the
membranes of these chemosensory cilia and culminate in excitation of the
olfactory receptor cell. Differential activation by odorants of distinct
groups of olfactory receptor cells generates patterns of neuronal activity
that encode odor quality and concentration. The identities of primary
odorant recognition sites at the ciliary membrane remain to be established.
However, a significant body of information has become available with
respect to olfactory transduction mechanisms. It is now becoming clear that
olfactory transduction involves the interplay of several second messenger
systems to control the responses of these exquisitely sensitive
chemosensory neurons.
