Genesis of cilia and microvilli of rat nasal epithelia during pre-natal development. II. Olfactory epithelium, a morphometric analysis

1985 ◽  
Vol 78 (1) ◽  
pp. 311-336
Author(s):  
B.P. Menco ◽  
A.I. Farbman
Keyword(s):  
Olfactory Receptor ◽  
Primary Cilia ◽  
Average Rate ◽  
Membrane Surface ◽  
Supporting Cells ◽  
Epithelial Surface ◽  
Olfactory Cilia ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Multiciliated Cells

Rat foetuses from intra-uterine days E14 through E22 (day before parturition) and adults were used for a quantitative scanning electron-microscopic examination of ciliogenesis in olfactory receptor cells and microvillogenesis in olfactory supporting cells. Four developmental stages in olfactory ciliogenesis can be discerned. Two of these are characterized by the presence of primary cilia only, the other two concern outgrowth in number and length of secondary cilia. (1) Primary cilia on undifferentiated cells; this stage occurs up to E14. (2) Primary cilia on differentiating olfactory receptor and also olfactory supporting cells. This stage begins at E14 and lasts, for the olfactory receptor cells, at least up to E22. On the supporting cells primary cilia are rarely observed after E18. Virtually all primary cilia are about 1 micron long. Up to E21 dendritic endings with primary cilia occur more frequently than those with any other number of cilia; all endings have a transitional stage in which they bear primary cilia only. (3) Secondary olfactory cilia increase in number. From E16 onwards the cells become multiciliated. Beginning at this stage and continuing up to E22 an average of one cilium per day is added to the endings. At E22 the average number of cilia observed per ending is about 70% of that in adults; more than 90% of the endings are multiciliated. From E15 to E22 the exchange rate between receptor cells with only primary cilia and multiciliated cells is about 0.5 X 10(6) cells/cm2 per day. When considered in the light of electrophysiological data on developing rats, our data suggest that when the cells have just primary cilia, they may respond indiscriminately to all odorants, whereas multiciliated cells display odorant specificity. (4) Secondary olfactory cilia increase in length. From E14 to E19 and over the whole population of receptor cells the cilia grow at an average rate of about 0.5 micron/day. Proximal parts of olfactory cilia are longer than primary cilia; olfactory cilia begin to taper in increasing numbers around E18. At E19 the receptive membrane surface, i.e. regions of the cells facing the nasal lumen, of individual cells is about 8%, and the increase in epithelial surface due to sprouting of cilia is 5% of such values in adult animals. Concomitant with the onset of tapering of olfactory cilia, i.e. around E18, microvilli of supporting cells show a spurt in growth from about 0.4 micron to about 1.3 micron. Unlike olfactory cilia they show no growth, on average, after E19.(ABSTRACT TRUNCATED AT 400 WORDS)

Genesis of cilia and microvilli of rat nasal epithelia during pre-natal development. I. Olfactory epithelium, qualitative studies

1985 ◽  
Vol 78 (1) ◽  
pp. 283-310 ◽  
Author(s):  
B.P. Menco ◽  
A.I. Farbman
Keyword(s):  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Primary Cilia ◽  
Supporting Cell ◽  
Supporting Cells ◽  
Epithelial Surface ◽  
Olfactory Cilia ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Atypical Cells

Rat foetuses from intra-uterine days E13 through E22 (day before parturition) and adults were used for a qualitative electron-microscopic investigation of the development of ciliated/microvillous surfaces of the olfactory epithelium. In the E13 and most of the E14 embryos the epithelial surface is not yet characteristically olfactory. Apical cell profiles show primary cilia. These can arise at the epithelial surface or below. From E14 onwards the epithelial surface acquires olfactory characteristics. Dendritic endings of the olfactory receptor cells can be found amidst microvillous profiles of supporting cells. Either cell type may bear primary cilia. From E16 onwards the receptor cells sprout multiple olfactory cilia, but cells with primary cilia are found throughout pre-natal development. These primary cilia are, at least for a while, retained during the formation of the secondary cilia. Primary cilia always have distinct necklaces at their base. Otherwise, especially with respect to their tips, their morphology can vary. Originally they have expanded tips (up to E14); later on such wide tips are no longer encountered (E16 and E17). Primary cilia of receptor cells never have wide tips. Appreciable numbers of endings with tapering olfactory cilia are discerned around E18 and especially E19. Throughout pre-natal development posterior/superior parts of the septal olfactory epithelium are more precocious than anterior/inferior parts, in particular in the region of transition with the respiratory epithelium. This advance in development includes total densities of dendritic endings of olfactory receptor cells, densities of multiciliated endings alone and lengths of supporting cell microvilli. This difference is discussed with respect to the topography of the olfactory epithelial surface in adult animals. In addition to the systematic topographic variation, a number of more local, apparently not-systematically distributed, topographic variations present during development are described. Most of these also occur in adult animals and they include heterogeneity in length of supporting cell microvilli and the presence of patches of supporting cells with rounded apical protuberances, of patches displaying dendrites with polyaxonemes rather than individual cilia and of scattered atypical cells (neither typical olfactory receptor nor olfactory supporting cells). At their surfaces such atypical cells can resemble inner-ear hair cells. Relative to olfactory receptor and supporting cells there are only very few atypical cells.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Na+-dependent Ca2+ Extrusion Governs Response Recovery in Frog Olfactory Receptor Cells

1998 ◽  
Vol 112 (5) ◽  
pp. 529-535 ◽  
Author(s):  
Johannes Reisert ◽  
H.R. Matthews
Keyword(s):  
Cyclic Nucleotide ◽  
Olfactory Receptor ◽  
Ionic Composition ◽  
External Solution ◽  
Free Solution ◽  
Olfactory Cilia ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Response Recovery ◽  
Extrusion Mechanism

To study the mechanism by which Ca2+, which enters during the odor response, is extruded during response recovery, recordings were made from isolated frog olfactory receptor cells using the suction pipette technique, while superfusing the olfactory cilia with solutions of modified ionic composition. When external Na+ was substituted with another cation, the response to odor was greatly prolonged. This prolongation of the response was similar irrespective of whether Na+ was replaced with Li+, which permeates the cyclic nucleotide-gated conductance, or choline, which does not. The prolonged current was greatly reduced by exposure to 300 μM niflumic acid, a blocker of the calcium-activated chloride channel, indicating that it is carried by this conductance, and abolished if Ca2+ was omitted from the external solution, demonstrating that Ca2+ influx is required for its generation. When the cilia were exposed to Na+-free solution after odor stimulation, the recovery of the response to a second stimulus from the adaptation induced by the first was greatly reduced. We conclude that a Na+-dependent Ca2+ extrusion mechanism is present in frog olfactory cilia and that it serves as the main mechanism that returns cytoplasmic Ca2+ concentration to basal levels after stimulation and mediates the normally rapid recovery of the odor response and the restoration of sensitivity after adaptation.

scholarly journals Expression of CD36 by Olfactory Receptor Cells and Its Abundance on the Epithelial Surface in Mice

PLoS ONE ◽  
2015 ◽  
Vol 10 (7) ◽  
pp. e0133412 ◽  
Author(s):  
Shinhye Lee ◽  
Ai Eguchi ◽  
Satoshi Tsuzuki ◽  
Shigenobu Matsumura ◽  
Kazuo Inoue ◽  
...  
Keyword(s):  
Olfactory Receptor ◽  
Epithelial Surface ◽  
Olfactory Receptor Cells ◽  
Receptor Cells

scholarly journals Cyclic nucleotide-gated channels of rat olfactory receptor cells: divalent cations control the sensitivity to cAMP.

1994 ◽  
Vol 103 (1) ◽  
pp. 87-106 ◽  
Author(s):  
J W Lynch ◽  
B Lindemann
Keyword(s):  
Cyclic Nucleotide ◽  
Olfactory Receptor ◽  
Divalent Cations ◽  
Membrane Surface ◽  
Regulatory Protein ◽  
Induced Response ◽  
Intact Cells ◽  
Cyclic Nucleotide Gated Channels ◽  
Olfactory Receptor Cells ◽  
Receptor Cells

cAMP-gated channels were studied in inside-out membrane patches excised from the apical cellular pole of isolated olfactory receptor cells of the rat. In the absence of divalent cations the dose-response curve of activation of patch current by cAMP had a KM of 4.0 microM at -50 mV and of 2.5 microM at +50 mV. However, addition of 0.2 or 0.5 mM Ca2+ shifted the KM of cAMP reversibly to the higher cAMP concentrations of 33 or 90 microM, respectively, at -50 mV. Among divalent cations, the relative potency for inducing cAMP affinity shifts was: Ca2+ > Sr2+ > Mn2+ > Ba2+ > Mg2+, of which Mg2+ (up to 3 mM) did not shift the KM at all. This potency sequence corresponds closely to that required for the activation of calmodulin. However, the Ca(2+)-sensitivity is lower than expected for a calmodulin-mediated action. Brief (60 s) transient exposure to 3 mM Mg2+, in the absence of other divalent cations, had a protective effect in that following washout of Mg2+, subsequent exposure to 0.2 mM Ca2+ no longer caused affinity shifts. This protection effect did not occur in intact cells and was probably a consequence of patch excision, possibly representing ablation of a regulatory protein from the channel cyclic nucleotide binding site. Thus, the binding of divalent cations, probably via a regulatory protein, controls the sensitivity of the cAMP-gated channels to cAMP. The influx of Ca2+ through these channels during the odorant response may rise to a sufficiently high concentration at the intracellular membrane surface to contribute to the desensitization of the odorant-induced response. The results also indicate that divalent cation effects on cyclic nucleotide-gated channels may depend on the sequence of pre-exposure to other divalent cations.

Ultrastructural aspects of olfactory signal transduction and its development

1994 ◽  
Vol 52 ◽  
pp. 142-143
Author(s):  
Bert Ph. M. Menco
Keyword(s):  
Signal Transduction ◽  
Olfactory Receptor ◽  
Receptor Cell ◽  
Freeze Substitution ◽  
Luminal Surface ◽  
Tissue Sections ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Olfactory Signal ◽  
Odor Molecule

Vertebrate olfactory receptor cells are specialized neurons that have numerous long tapering cilia. The distal parts of these cilia line the interface between the external odorous environment and the luminal surface of the olfactory epithelium. The length and number of these cilia results in a large surface area that presumably increases the chance that an odor molecule will meet a receptor cell. Advanced methods of cryoprepration and immuno-gold labeling were particularly useful to preserve the delicate ultrastructural and immunocytochemical features of olfactory cilia required for localization of molecules involved in olfactory signal-transduction. We subjected olfactory tissues to freeze-substitution in acetone (unfixed tissues) or methanol (fixed tissues) followed by low temperature embedding in Lowicryl K11M for that purpose. Tissue sections were immunoreacted with several antibodies against proteins that are presumably important in olfactory signal-transduction.

Presynaptic Afferent Inhibition of Lobster Olfactory Receptor Cells: Reduced Action-Potential Propagation Into Axon Terminals

1998 ◽  
Vol 80 (2) ◽  
pp. 1011-1015 ◽  
Author(s):  
Matt Wachowiak ◽  
Lawrence B. Cohen
Keyword(s):  
Action Potential ◽  
Olfactory Receptor ◽  
Receptor Cell ◽  
Action Potential Propagation ◽  
Cell Axon ◽  
Axon Terminals ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Afferent Inhibition ◽  
Reduced Action

Wachowiak, Matt and Lawrence B. Cohen. Presynaptic afferent inhibition of lobster olfactory receptor cells: reduced action-potential propagation into axon terminals. J. Neurophysiol. 80: 1011–1015, 1998. Action-potential propagation into the axon terminals of olfactory receptor cells was measured with the use of voltage-sensitive dye imaging in the isolated spiny lobster brain. Conditioning shocks to the olfactory nerve, known to cause long-lasting suppression of olfactory lobe neurons, allowed the selective imaging of activity in receptor cell axon terminals. In normal saline the optical signal from axon terminals evoked by a test stimulus was brief (40 ms) and small in amplitude. In the presence of low-Ca2+/high-Mg2+ saline designed to reduce synaptic transmission, the test response was unchanged in time course but increased significantly in amplitude (57 ± 16%, means ± SE). This increase suggests that propagation into receptor cell axon terminals is normally suppressed after a conditioning shock; this suppression is presumably synaptically mediated. Thus our results show that presynaptic inhibition occurs at the first synapse in the olfactory pathway and that the inhibition is mediated, at least in part, via suppression of action-potential propagation into the presynaptic terminal.

Histamine-induced modulation of olfactory receptor neurones in two species of lobster, Panulirus argus and Homarus americanus

1989 ◽  
Vol 145 (1) ◽  
pp. 133-146 ◽  
Author(s):  
T. A. Bayer ◽  
T. S. McClintock ◽  
U. Grunert ◽  
B. W. Ache
Keyword(s):  
Receptor Antagonist ◽  
Olfactory Receptor ◽  
Single Cells ◽  
Homarus Americanus ◽  
Chloride Ions ◽  
Electrophysiological Recording ◽  
Stimulus Response ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
The One

In two species of lobster, application of the biogenic amine, histamine (HA), to the soma of olfactory receptor cells suppressed both spontaneous and odour-evoked activity, as shown by electrophysiological recording from single cells. The action of HA was graded, reversible, specific to HA, and had a threshold between 0.1 and 1 mumol l-1. HA increased the conductance of the membrane, primarily to chloride ions. The vertebrate HA receptor antagonist, cimetidine, and the nicotinic receptor antagonist, d-tubocurarine, but not other known vertebrate HA receptor antagonists, reversibly blocked the action of HA. These results suggest that a histaminergic mechanism modulates stimulus-response coupling in lobster olfactory receptor cells and potentially implicate a novel HA receptor, pharmacologically similar to the one recently described in the visual system of flies.

Sign in / Sign up

Export Citation Format

Share Document