scholarly journals Responses of the Rat Olfactory Epithelium to Retronasal Air Flow

2007 ◽  
Vol 97 (3) ◽  
pp. 1941-1950 ◽  
Author(s):  
John W. Scott ◽  
Humberto P. Acevedo ◽  
Lisa Sherrill ◽  
Maggie Phan
Keyword(s):  
Olfactory Bulb ◽  
Nasal Cavity ◽  
Olfactory Epithelium ◽  
Air Flow ◽  
Positive Pressure ◽  
Stimulus Concentration ◽  
Stimulus Modes

Responses of the rat olfactory epithelium were assessed with the electroolfactogram while odorants were presented to the external nares with an artificial sniff or to the internal nares by positive pressure. A series of seven odorants that varied from very polar, hydrophilic odorants to very nonpolar, hydrophobic odorants were used. Although the polar odorants activated the dorsal olfactory epithelium when presented by the external nares (orthonasal presentation), they were not effective when forced through the nasal cavity from the internal nares (retronasal presentation). However, the nonpolar odorants were effective in both stimulus modes. These results were independent of stimulus concentration or of humidity of the carrier air. Similar results were obtained with multiunit recordings from olfactory bulb. These results help to explain why human investigations often report differences in the sensation or ability to discriminate odorants presented orthonasally versus retronasally. The results also strongly support the importance of odorant sorption in normal olfactory processes.

scholarly journals Temporal patterns and selectivity in the unitary responses of olfactory receptors in the tiger salamander to odor stimulation.

1979 ◽  
Vol 74 (1) ◽  
pp. 17-36 ◽  
Author(s):  
F Baylin
Keyword(s):  
Olfactory Bulb ◽  
Olfactory Epithelium ◽  
Flow Rate ◽  
Olfactory Receptors ◽  
Temporal Patterns ◽  
Tiger Salamander ◽  
Gas Chromatograph ◽  
Firing Rates ◽  
Stimulus Concentration ◽  
The Cross

Temporal patterns and selectivity in unitary responses of 100 single olfactory receptors in the tiger salamander to odor stimulation were investigated. An olfactometer which permitted control of stimulus concentration, duration, and flow rate was calibrated with a gas chromatograph. Stimulus pulses were monitored by recording the electroolfactogram from the surface of the olfactory epithelium. Both diphasic and triphasic spikes were recorded extracellularly. No discernible differences in types of responses, reproducibility of responses, and cross-unit distribution of spontaneous rates distinguished diphasic from triphasic units. The cross-unit selectivity in responses to the seven olfactory stimulants used and the range of odorant concentrations which effectively evoked these responses suggest variations in types and number of types of receptive sites on each cell. Temporal patterns in the unitary responses were generally less complex than those observed in the olfactory bulb. Phasic stimulations evoked phasic patterns. Tonic stimulations evoked phasic/tonic patterns. Occasionally poststimulus depressions or elevations in firing rates were observed. The nature of these patterns varied somewhat with odorant concentration for a particular unit.

scholarly journals Extinction reverses olfactory fear-conditioned increases in neuron number and glomerular size

2015 ◽  
Vol 112 (41) ◽  
pp. 12846-12851 ◽  
Author(s):  
Filomene G. Morrison ◽  
Brian G. Dias ◽  
Kerry J. Ressler
Keyword(s):  
Olfactory Bulb ◽  
Learning And Memory ◽  
Olfactory Epithelium ◽  
Olfactory System ◽  
Structural Changes ◽  
Freezing Behavior ◽  
Extinction Training ◽  
Odor Stimulus ◽  
Main Olfactory Epithelium ◽  
Odor Learning

Although much work has investigated the contribution of brain regions such as the amygdala, hippocampus, and prefrontal cortex to the processing of fear learning and memory, fewer studies have examined the role of sensory systems, in particular the olfactory system, in the detection and perception of cues involved in learning and memory. The primary sensory receptive field maps of the olfactory system are exquisitely organized and respond dynamically to cues in the environment, remaining plastic from development through adulthood. We have previously demonstrated that olfactory fear conditioning leads to increased odorant-specific receptor representation in the main olfactory epithelium and in glomeruli within the olfactory bulb. We now demonstrate that olfactory extinction training specific to the conditioned odor stimulus reverses the conditioning-associated freezing behavior and odor learning-induced structural changes in the olfactory epithelium and olfactory bulb in an odorant ligand-specific manner. These data suggest that learning-induced freezing behavior, structural alterations, and enhanced neural sensory representation can be reversed in adult mice following extinction training.

scholarly journals The Development of Olfactory Organ of Lissotriton Vulgaris (Amphibia, Caudata)

2015 ◽  
Vol 49 (6) ◽  
pp. 559-566 ◽  
Author(s):  
M. F. Kovtun ◽  
Ya. V. Stepanyuk
Keyword(s):  
Nasal Cavity ◽  
Olfactory Epithelium ◽  
Vomeronasal Organ ◽  
Developmental Period ◽  
Olfactory Organ ◽  
Peripheral Part ◽  
Lissotriton Vulgaris ◽  
Olfactory Analyzer ◽  
Gland Development ◽  
Olfactory Pit

Abstract The Development of Olfactory Organ of Lissotriton vulgaris (Amphibia, Caudata). Kovtun, M. F, Stepanyuk, Ya. V. - Using common histological methods, the morphogenesis of olfactory analyzer peripheral part of Lissotriton vulgaris (Amphibia, Caudata) was studied, during the developmental period starting with olfactory pit laying and finishing with definitive olfactory organ formation. Special attention is paid to vomeronasal organ and vomeronasal gland development. Reasoning from obtained data, we consider that vomeronasal organ emerged as the result of olfactory epithelium and nasal cavity differentiation.

scholarly journals The Endothelin-A Receptor Antagonist Zibotentan Induces Damage to the Nasal Olfactory Epithelium Possibly Mediated in Part through Type 2 Innate Lymphoid Cells

2018 ◽  
Vol 47 (2) ◽  
pp. 150-164 ◽  
Author(s):  
Marian A. Esvelt ◽  
Zachary T. Freeman ◽  
Alexander T. Pearson ◽  
Jack R. Harkema ◽  
Gregory T. Clines ◽  
...  
Keyword(s):  
Nasal Cavity ◽  
Receptor Antagonist ◽  
Olfactory Epithelium ◽  
Nude Mice ◽  
Animal Health ◽  
Lymphoid Cells ◽  
Athymic Nude Mice ◽  
Endothelin A Receptor ◽  
Endothelin A

Zibotentan, an endothelin-A receptor antagonist, has been used in the treatment of various cardiovascular disorders and neoplasia. Castrated athymic nude mice receiving zibotentan for a preclinical xenograft efficacy study experienced weight loss, gastrointestinal bloat, and the presence of an audible respiratory click. Human side effects have been reported in the nasal cavity, so we hypothesized that the nasal cavity is a target for toxicity in mice receiving zibotentan. Lesions in the nasal cavity predominantly targeted olfactory epithelium in treated mice and were more pronounced in castrated animals. Minimal lesions were present in vehicle control animals, which suggested possible gavage-related reflux injury. The incidence, distribution, and morphology of lesions suggested direct exposure to the nasal mucosa and a possible systemic effect targeting the olfactory epithelium, driven by a type 2 immune response, with group 2 innate lymphoid cell involvement. Severe nasal lesions may have resulted in recurrent upper airway obstruction, leading to aerophagia and associated clinical morbidity. These data show the nasal cavity is a target of zibotentan when given by gavage in athymic nude mice, and such unanticipated and off-target effects could impact interpretation of research results and animal health in preclinical studies.

scholarly journals Histological Properties of the Nasal Cavity and Olfactory Bulb of the Japanese Jungle Crow Corvus macrorhynchos

2009 ◽  
Vol 34 (7) ◽  
pp. 581-593 ◽  
Author(s):  
M. Yokosuka ◽  
A. Hagiwara ◽  
T. R. Saito ◽  
N. Tsukahara ◽  
M. Aoyama ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Nasal Cavity ◽  
Jungle Crow ◽  
Corvus Macrorhynchos

scholarly journals The Route by Which Intranasally Delivered Stem Cells Enter the Central Nervous System

2018 ◽  
Vol 27 (3) ◽  
pp. 501-514 ◽  
Author(s):  
Carlos Galeano ◽  
Zhifang Qiu ◽  
Anuja Mishra ◽  
Steven L. Farnsworth ◽  
Jacob J. Hemmi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Central Nervous System ◽  
Nervous System ◽  
Nasal Cavity ◽  
Olfactory Epithelium ◽  
Cribriform Plate ◽  
Intranasal Delivery ◽  
Immunodeficient Mice ◽  
Stem Cell Delivery ◽  
The Central Nervous System

Intranasal administration is a promising route of delivery of stem cells to the central nervous system (CNS). Reports on this mode of stem cell delivery have not yet focused on the route across the cribriform plate by which cells move from the nasal cavity into the CNS. In the current experiments, human mesenchymal stem cells (MSCs) were isolated from Wharton’s jelly of umbilical cords and were labeled with extremely bright quantum dots (QDs) in order to track the cells efficiently. At 2 h after intranasal delivery in immunodeficient mice, the labeled cells were found under the olfactory epithelium, crossing the cribriform plate adjacent to the fila olfactoria, and associated with the meninges of the olfactory bulb. At all times, the cells were separate from actual nerve tracts; this location is consistent with them being in the subarachnoid space (SAS) and its extensions through the cribriform plate into the nasal mucosa. In their location under the olfactory epithelium, they appear to be within an expansion of a potential space adjacent to the turbinate bone periosteum. Therefore, intranasally administered stem cells appear to cross the olfactory epithelium, enter a space adjacent to the periosteum of the turbinate bones, and then enter the SAS via its extensions adjacent to the fila olfactoria as they cross the cribriform plate. These observations should enhance understanding of the mode by which stem cells can reach the CNS from the nasal cavity and may guide future experiments on making intranasal delivery of stem cells efficient and reproducible.

Patterned response to odor in mammalian olfactory bulb: the influence of intensity

1986 ◽  
Vol 56 (3) ◽  
pp. 572-597 ◽  
Author(s):  
M. Meredith
Keyword(s):  
Olfactory Bulb ◽  
Firing Rate ◽  
Time Course ◽  
Temporal Patterns ◽  
High Concentration ◽  
Lateral Olfactory Tract ◽  
Inhibitory Circuits ◽  
Intensity Response ◽  
Stimulus Concentration ◽  
Single Response

Responses of single neurons in the olfactory bulb of anesthetized hamsters were recorded extracellularly while odors of defined concentration and time course were delivered to the olfactory system at constant flow. Responses could be either excitatory or suppressive, as judged by the first distinguishable change in firing rate during odor delivery. However, when the time course of the response was examined in more detail, approximately one-third of all tests and one-half of the tests at high concentration resulted in complex temporal patterns of firing rate that involved both increases and decreases with respect to spontaneous activity. Approximately two-thirds of all tests produced responses where increased firing rate preceded any distinguishable suppression. Excitatory and suppressive responses were each classified into four groups according to their temporal patterns. Different patterns were not equally represented in the data and the proportions of patterns elicited by the same odor changed with stimulus intensity. Complex responses, where temporal patterns included periods of firing rate above and below spontaneous rate, were increasingly common and intensity was increased. Magnitude of response is difficult to define when a single response includes both increases and decreases of firing rate but more than half of the neurons that responded to more than one stimulus concentration clearly had nonmonotonic intensity-response functions. Forty-one out of 101 neurons were classified as output cells because they could be driven at short constant latency by lateral olfactory tract stimulation. Their responses were not clearly different from the remaining cells that could not be classified as output cells. The contribution of the inhibitory circuits of the olfactory bulb to the generation of patterned response and to changes in pattern with intensity are discussed. The lateral inhibitory circuits of the bulb appear to be sufficient to explain the data presented here.

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