scholarly journals PACAP Is Present in the Olfactory System and Evokes Calcium Transients in Olfactory Receptor Neurons

2003 ◽  
Vol 90 (4) ◽  
pp. 2711-2719 ◽  
Author(s):  
Colleen C. Hegg ◽  
Edmund Au ◽  
A. Jane Roskams ◽  
Mary T. Lucero
Keyword(s):  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Olfactory Receptor Neurons ◽  
Olfactory Ensheathing Cells ◽  
Adult Mice ◽  
Supportive Role ◽  
Ensheathing Cells ◽  
Key Factor ◽  
Mature Neurons ◽  
Receptor Neurons

Pituitary adenylate cyclase activating peptide (PACAP), a neuroregulatory peptide, is found in germinative regions of the CNS, including the olfactory bulb, throughout adulthood. We show that 1) PACAP immunoreactivity is also present in the neonatal mouse and adult mouse and rat olfactory epithelium, 2) PACAP expression pattern differs between neonatal and adult mice, and 3) PACAP is produced by olfactory ensheathing cells. PACAP may thus be a key factor in the uniquely supportive role of olfactory ensheathing cells in regeneration of neurons from olfactory epithelium and lesioned spinal cord. Using calcium imaging, we demonstrated physiological responses to PACAP in both neonatal and adult olfactory receptor neurons (ORNs). We propose that PACAP plays an important role in normal turnover of ORNs by providing neurotrophic support during development and regeneration and neuroprotective support of mature neurons.

Neuronal nitric oxide synthase-like immunoreactivity in olfactory epithelium throughout the life cycle of the sea lamprey, Petromyzon marinus L.

2000 ◽  
Vol 78 (3) ◽  
pp. 346-351 ◽  
Author(s):  
Hong N Hua ◽  
Aliya U Zaidi ◽  
Barbara S Zielinski
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Petromyzon Marinus ◽  
Neuronal Nitric Oxide Synthase ◽  
Sea Lamprey ◽  
Olfactory Receptor Neurons ◽  
Receptor Neurons ◽  
Oxide Synthase

This study is the first to show that neuronal nitric oxide synthase-like immunoreactivity is located in the olfactory epithelium at all developmental stages of a vertebrate. Western immunoblotting of sea lamprey (Petromyzon marinus L.) olfactory mucosa with a monoclonal antibody against the NADPH-binding epitope of neuronal nitric oxide synthase showed that the molecular mass of this protein was 200 kDa. In the larval stage, neuronal nitric oxide synthase-like immunoreactivity was strongest in the basal region of the olfactory epithelium, the site of proliferating olfactory receptor neurons. This staining gradually diminished as the life cycle progressed. In the juvenile stage, the intensity of neuronal nitric oxide synthase-like immunoreactivity was striking in the wide cell bodies and dendrites on olfactory receptor neurons. These results confirm previous evidence that nitric oxide modulates development in the olfactory epithelium.

scholarly journals Comparison of the Nasal Olfactory Organs of Various Species of Lizardfishes (Teleostei: Aulopiformes: Synodontidae) with Additional Remarks on the Brain

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
L. Fishelson ◽  
D. Golani ◽  
B. Galil ◽  
M. Goren
Keyword(s):  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Olfactory Receptor Neurons ◽  
Adult Fish ◽  
Supporting Cells ◽  
Receptor Neurons ◽  
Olfactory Organs ◽  
Species Specific ◽  
The Brain

The olfactory organs of lizardfishes (Synodontidae) are situated in two capsules connected to the outside by incurrent and excurrent openings. The olfactory epithelium is in form of petal rosettes each composed of lamellae and a rephe, and bear olfactory receptor neurons, supporting cells and cells with kinocillia. The dimension of rosettes and lamellae, as well as the number of lamellae, increase with growth of the fish; until in adult fish these parameters remaine constant, species specific. In adultSynodusspp. andTrachinocephalus myopsthe rosettes are 3.5–4.0 mm long, with 5–8 lamellae, whereas inSauridaspp. they are 8.0 mm and possess up tp 22 lamellae. The number of ORN ranges from 2,600 on the smaller lamellae to 20,000 on the largest ones. The number of ORN/m of olfactory is ca. 30,000 inSauridaspp. Thus the rosettes ofS. macrolepiswith 20 lamellae possess a total of ca. 170,000 ORN, whereas those ofSy. variegatusandT. myopswith the average of six lamellae possess only ca. 50,000–65,000 ORN. The olfactory nerves lead from the rosettes to the olfactory balbs situated on the olfactory lobes. The differences among the species in olfactory organs are discussed in correlation with their distribution.

scholarly journals Evidence of SARS-CoV2 entry protein ACE2 in the human nose and olfactory bulb

2020 ◽  
Author(s):  
M. Klingenstein ◽  
S. Klingenstein ◽  
P.H. Neckel ◽  
A. F. Mack ◽  
A. Wagner ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Respiratory Epithelium ◽  
Olfactory Receptor Neurons ◽  
Basal Cells ◽  
Sustentacular Cells ◽  
Glandular Cells ◽  
Receptor Neurons ◽  
Human Nose

ABSTRACTUsually, pandemic COVID-19 disease, caused by SARS-CoV2, presents with mild respiratory symptoms such as fever, cough but frequently also with anosmia and neurological symptom. Virus-cell fusion is mediated by Angiotensin-Converting Enzyme 2 (ACE2) and Transmembrane Serine Protease 2 (TMPRSS2) with their organ expression pattern determining viral tropism. Clinical presentation suggests rapid viral dissemination to central nervous system leading frequently to severe symptoms including viral meningitis. Here, we provide a comprehensive expression landscape of ACE2 and TMPRSS2 proteins across human, post-mortem nasal and olfactory tissue. Sagittal sections through the human nose complemented with immunolabelling of respective cell types represent different anatomically defined regions including olfactory epithelium, respiratory epithelium of the nasal conchae and the paranasal sinuses along with the hardly accessible human olfactory bulb. ACE2 can be detected in the olfactory epithelium, as well as in the respiratory epithelium of the nasal septum, the nasal conchae and the paranasal sinuses. ACE2 is located in the sustentacular cells and in the glandular cells in the olfactory epithelium, as well as in the basal cells, glandular cells and epithelial cells of the respiratory epithelium. Intriguingly, ACE2 is not expressed in mature or immature olfactory receptor neurons and basal cells in the olfactory epithelium. Similarly ACE2 is not localized in the olfactory receptor neurons albeit the olfactory bulb is positive. Vice versa, TMPRSS2 can also be detected in the sustentacular cells and the glandular cells of the olfactory epithelium.Our findings provide the basic anatomical evidence for the expression of ACE2 and TMPRSS2 in the human nose, olfactory epithelium and olfactory bulb. Thus, they are substantial for future studies that aim to elucidate the symptom of SARS-CoV2 induced anosmia of via the olfactory pathway.

Odorant Concentration Dependence in Electroolfactograms Recorded From the Human Olfactory Epithelium

2009 ◽  
Vol 102 (4) ◽  
pp. 2121-2130 ◽  
Author(s):  
Hadas Lapid ◽  
Han-Seok Seo ◽  
Benno Schuster ◽  
Elad Schneidman ◽  
Yehudah Roth ◽  
...  
Keyword(s):  
Concentration Dependence ◽  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Isovaleric Acid ◽  
Valeric Acid ◽  
Olfactory Receptor Neurons ◽  
Olfactory Coding ◽  
Perceived Intensity ◽  
Receptor Neurons

Electroolfactograms (EOGs) are the summated generator potentials of olfactory receptor neurons measured directly from the olfactory epithelium. To validate the sensory origin of the human EOG, we set out to ask whether EOGs measured in humans were odorant concentration dependent. Each of 22 subjects (12 women, mean age = 23.3 yr) was tested with two odorants, either valeric acid and linalool ( n = 12) or isovaleric acid and l-carvone ( n = 10), each delivered at four concentrations diluted with warm (37°C) and humidified (80%) odorless air. In behavior, increased odorant concentration was associated with increased perceived intensity (all F > 5, all P < 0.001). In EOG, increased odorant concentration was associated with increased area under the EOG curve (all F > 8, all P < 0.001). These findings substantiate EOG as a tool for probing olfactory coding directly at the level of olfactory receptor neurons in humans.

scholarly journals Patch-clamp studies of isolated mouse olfactory receptor neurons.

1987 ◽  
Vol 90 (1) ◽  
pp. 95-125 ◽  
Author(s):  
R A Maue ◽  
V E Dionne
Keyword(s):  
Patch Clamp ◽  
Olfactory Receptor ◽  
Membrane Conductance ◽  
Olfactory Receptor Neurons ◽  
Membrane Properties ◽  
K Channel ◽  
Patch Clamp Technique ◽  
Adult Mice ◽  
Intracellular Ca ◽  
Receptor Neurons

Olfactory receptor neurons isolated from embryonic, neonatal, and adult mice were studied using the patch-clamp technique. Several distinct types of ion channels were characterized in patches of membrane from the neuronal soma and the dendritic knob of receptor neurons, including a 130-pS Ca++-activated K+ channel with voltage-dependent kinetics, an 80-pS Ca++-activated K+ channel with voltage-insensitive kinetics, a 25-pS K+ channel with properties similar to inward rectifiers, and a 40-pS K+ channel that was activated and then inactivated by rapid depolarization. Evidence of large-conductance (greater than 200 pS) Cl- channels, which were Ca++ insensitive and increasingly active at depolarizing membrane potentials, and voltage-activated Ca++ channels (16 pS) was also obtained. From K+ channel activity recorded from cell-attached patches, the intracellular [Ca++] was inferred to be below 0.1 microM, and the membrane potential was inferred to be approximately -50 mV. The receptor neurons had high input resistances, and action potentials could be elicited by picoampere amounts of depolarizing current. The receptor neurons responded to applied odorant molecules and to forskolin with increases in membrane conductance. These results provide a description of the membrane properties of olfactory receptor neurons and a basis for understanding their electrical activity and response to odorants.

Physiological activity of newly differentiated olfactory receptor neurons correlated with morphological recovery from olfactory nerve section in the salamander

1981 ◽  
Vol 45 (3) ◽  
pp. 529-549 ◽  
Author(s):  
P. A. Simmons ◽  
T. V. Getchell
Keyword(s):  
Olfactory Bulb ◽  
Spontaneous Activity ◽  
Histological Examination ◽  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Receptor Cell ◽  
Olfactory Nerve ◽  
Olfactory Receptor Neurons ◽  
Nerve Section ◽  
Receptor Neurons

1. Extracellular unitary recordings were made from the olfactory epithelium of the salamander, Ambystoma tigrinum, at numerous time points following olfactory nerve section. Unitary response properties were correlated with histological examination of the same tissues. 2. At 10 days following nerve section, unitary activity was rarely recorded in all regions of the epithelium. Histological examination indicated that virtually the entire mature olfactory receptor cell population had undergone retrograde degeneration. Transneuronal degeneration was not observed in the olfactory bulb, although the olfactory nerve and glomerular layers were substantially reduced in size. 3. At subsequent times, unitary impulse activity gradually returned, consisting of both spontaneous activity and odor-evoked discharges. Anatomical recovery of the olfactory epithelium preceded that of the olfactory bulb. A positive correlation was found between neuronal differentiation in the olfactory epithelium and the recovery of receptor cell function. 4. Patterns of spontaneous activity, odor specificities, intensity-response functions, and adaptive properties studied in newly differentiated olfactory receptor neurons were indistinguishable from those observed in control units. This indicated that these properties were intrinsic to the receptor neurons. 5. Spontaneously active and responsive units were encountered prior to olfactory nerve connection with the bulb. It is concluded that receptor neurons pass through two phases of functional maturity: the first independent of bulbar contact and the second dependent on presumed synaptic contact with bulbar neurons.

scholarly journals Evidence of SARS-CoV2 Entry Protein ACE2 in the Human Nose and Olfactory Bulb

2021 ◽  
pp. 1-10
Author(s):  
Moritz Klingenstein ◽  
Stefanie Klingenstein ◽  
Peter H. Neckel ◽  
Andreas F. Mack ◽  
Andreas P. Wagner ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Respiratory Epithelium ◽  
Olfactory Receptor Neurons ◽  
Basal Cells ◽  
Sustentacular Cells ◽  
Glandular Cells ◽  
Receptor Neurons ◽  
Human Nose

Usually, pandemic COVID-19 disease, caused by SARS-CoV2, presents with mild respiratory symptoms such as fever, cough, but frequently also with anosmia and neurological symptoms. Virus-cell fusion is mediated by angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) with their organ expression pattern determining viral tropism. Clinical presentation suggests rapid viral dissemination to the central nervous system leading frequently to severe symptoms including viral meningitis. Here, we provide a comprehensive expression landscape of ACE2 and TMPRSS2 proteins across human postmortem nasal and olfactory tissue. Sagittal sections through the human nose complemented with immunolabelling of respective cell types represent different anatomically defined regions including olfactory epithelium, respiratory epithelium of the nasal conchae and the paranasal sinuses along with the hardly accessible human olfactory bulb. ACE2 can be detected in the olfactory epithelium as well as in the respiratory epithelium of the nasal septum, the nasal conchae, and the paranasal sinuses. ACE2 is located in the sustentacular cells and in the glandular cells in the olfactory epithelium as well as in the basal cells, glandular cells, and epithelial cells of the respiratory epithelium. Intriguingly, ACE2 is not expressed in mature or immature olfactory receptor neurons and basal cells in the olfactory epithelium. Similarly, ACE2 is not localized in the olfactory receptor neurons albeit the olfactory bulb is positive. Vice versa, TMPRSS2 can also be detected in the sustentacular cells and the glandular cells of the olfactory epithelium. Our findings provide the basic anatomical evidence for the expression of ACE2 and TMPRSS2 in the human nose, olfactory epithelium, and olfactory bulb. Thus, they are substantial for future studies that aim to elucidate the symptom of SARS-CoV2 induced anosmia via the olfactory pathway.

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