The morphological and functional development of the stria vascularis in miniature pigs

2017 ◽  
Vol 29 (3) ◽  
pp. 585 ◽  
Author(s):  
Weiwei Guo ◽  
Haijin Yi ◽  
Zhang Yan ◽  
Lili Ren ◽  
Lei Chen ◽  
...  
Keyword(s):  
Animal Studies ◽  
Stria Vascularis ◽  
Organ Of Corti ◽  
Lateral Wall ◽  
Cell Types ◽  
Endocochlear Potential ◽  
Miniature Pigs ◽  
Functional Development ◽  
Transmission Electron ◽  
Different Types

The purpose of this study was to examine the morphological and functional development of the lateral wall of the scala media of the cochlea in miniature pigs; light and transmission electron microscopy and electrophysiology were used for this purpose. We showed that the lateral wall of the scala media of the cochlea appears at embryonic Day 21 (E21) when the cochlear duct begins to form. From E28 to E49, the lateral wall can be distinguished according to its position along the cochlea. At E56, cells in the lateral wall begin to differentiate into three different types. At E70, three cell types, marginal, intermediate and basal, can be clearly distinguished. At E91, the stria vascularis is adult-like and the organ of Corti is also morphologically mature. The average endocochlear potential measured from the second turn of the cochlea (at E98, postnatal Day 1 (P1), P13 and P30) was 71.4 ± 2.5 (n = 7), 78.8 ± 1.5 (n = 10), 77.3 ± 2.3 (n = 10) and 78.0 ± 2.1 mV (n = 10), respectively. Our results suggest that in miniature pigs the stria vascularis develops during the embryonic period, concurrent with maturation of the organ of Corti. The magnitude of the endocochlear potential reached its mature level when the stria vascularis was morphologically adult-like at E98. These findings provide a morphological and functional basis for future animal studies using the miniature pig model concerning the pathogenesis of various inner-ear diseases.

scholarly journals Expression of Gap Junction Protein Connexin43 in the Adult Rat Cochlea: Comparison with Connexin26

2003 ◽  
Vol 51 (7) ◽  
pp. 903-912 ◽  
Author(s):  
Toshihiro Suzuki ◽  
Tetsuro Takamatsu ◽  
Masahito Oyamada
Keyword(s):  
Gap Junction ◽  
Stria Vascularis ◽  
Three Dimensional ◽  
Organ Of Corti ◽  
Structural Difference ◽  
Lateral Wall ◽  
Spiral Ligament ◽  
Adult Rat ◽  
Junction Protein ◽  
Rat Cochlea

To elucidate whether the two different gap junction proteins connexin43 (Cx43) and connexin26 (Cx26) are expressed and localized in a similar manner in the adult rat cochlea, we performed three-dimensional confocal microscopy using cryosections and surface preparations. In the cochlear lateral wall, Cx43-positive spots were localized mainly in the stria vascularis and only a few spots were present in the spiral ligament, whereas Cx26-positive spots were detected in both the stria vascularis and the spiral ligament. In the spiral limbus, Cx43 was widely distributed, whereas Cx26 was more concentrated on the side facing the scala vestibuli and in the basal portion. In the organ of Corti, Cx43-positive spots were present between the supporting cells but they were fewer and much smaller than those of Cx26. These data demonstrated distinct differences between Cx43 and Cx26 in expression and localization in the cochlea. In addition, the area of overlap of zonula occludens-1 (ZO-1) immunolabeling with Cx43-positive spots was small, whereas it was fairly large with Cx26-positive spots in the cochlear lateral wall, suggesting that the differences are not associated with the structural difference between carboxyl terminals, i.e., those of Cx43 possess sequences for binding to ZO-1, whereas those of Cx26 lack these binding sequences.

Adaptation for Carnivory in the West Australian pitcher plant Cephalotus follicularis Labill

1984 ◽  
Vol 32 (6) ◽  
pp. 595 ◽  
Author(s):  
DM Parkes ◽  
ND Hallam
Keyword(s):  
Cell Types ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
The West ◽  
Pitcher Plant ◽  
Mesophyll Cells ◽  
Surface Microtopography ◽  
Transmission Electron ◽  
Different Types ◽  
Gland Tissue

The West Australian pitcher plant Cephalotus follicularis has adaptive structures for carnivory including modified leaves as pitfall containers, specialized surface microtopography to reduce adhesion of insect footpads and the development of gland tissue that secretes digestive enzymes. Gland masses on the lateral pitcher walls are made up of unspecialized mesophyll cells supporting two different types of gland. Cephalotus is geographically and taxonomically isolated from other pitcher plants. A detailed scanning electron and transmission electron microscopy study of the cell types within the pitchers of Cephalotus was carried out and the evolutionary and taxonomic significance of its adaptions to carnivory are discussed.

Development of mammalian endocochlear potential: normal ontogeny and effects of anoxia

1986 ◽  
Vol 250 (3) ◽  
pp. R493-R498 ◽  
Author(s):  
N. K. Woolf ◽  
A. F. Ryan ◽  
J. P. Harris
Keyword(s):  
Glucose Metabolism ◽  
Mongolian Gerbil ◽  
Hair Cells ◽  
Stria Vascularis ◽  
Organ Of Corti ◽  
Endocochlear Potential ◽  
Cochlear Microphonic ◽  
Cochlear Hair Cells ◽  
Apical Membranes ◽  
Cochlear Microphonic Potential

The development of the positive endocochlear potential (EP), the negative anoxic EP, and the organ of Corti potential were measured at various postnatal ages in the Mongolian gerbil, beginning at 8 days after birth (DAB). The organ of Corti potential (OCP) was present at 8 DAB but averaged 21% less than the adult value. OCP increased regularly with age, reaching adult values of -90 mV by 14 DAB. The positive EP was first observed at 10 DAB, at which age it averaged only 2-3 mV. This potential increased monotonically between 10 and 20 DAB, by which time it had reached the adult value of 75 mV. Anoxia did not result in a negative EP until 12 DAB, at which age this potential averaged -7 mV. The negative anoxic EP matured more rapidly than the positive EP, achieving the adult value of 40 mV by 18 DAB. During development the positive EP appeared to closely parallel the maturation of glucose metabolism in the stria vascularis. The negative anoxic EP was more closely related temporally to the development of cochlear microphonic potential (CM) thresholds. It is hypothesized that changes which occur between 10 and 16 DAB in the apical membranes of the cochlear hair cells contribute to the maturation of both CM and the negative anoxic EP.

Gastric type H+,K+-ATPase in the cochlear lateral wall is critically involved in formation of the endocochlear potential

2006 ◽  
Vol 291 (5) ◽  
pp. C1038-C1048 ◽  
Author(s):  
Toshiaki Shibata ◽  
Hiroshi Hibino ◽  
Katsumi Doi ◽  
Toshihiro Suzuki ◽  
Yasuo Hisa ◽  
...  
Keyword(s):  
Stria Vascularis ◽  
Critical Role ◽  
Specific Inhibitor ◽  
Lateral Wall ◽  
Endocochlear Potential ◽  
Pcr Analysis ◽  
Spiral Ligament ◽  
Gastric Type ◽  
Marginal Cells ◽  
Strong Immunoreactivity

Cochlear endolymph has a highly positive potential of approximately +80 mV known as the endocochlear potential (EP). The EP is essential for hearing and is maintained by K+ circulation from perilymph to endolymph through the cochlear lateral wall. Various K+ transport apparatuses such as the Na+,K+-ATPase, the Na+-K+-2Cl− cotransporter, and the K+ channels Kir4.1 and KCNQ1/KCNE1 are expressed in the lateral wall and are known to play indispensable roles in cochlear K+ circulation. The gastric type of the H+,K+-ATPase was also shown to be expressed in the cochlear lateral wall (Lecain E, Robert JC, Thomas A, and Tran Ba Huy P. Hear Res 149: 147–154, 2000), but its functional role has not been well studied. In this study we examined the precise localization of H+,K+-ATPase in the cochlea and its involvement in formation of EP. RT-PCR analysis showed that the cochlea expressed mRNAs of gastric α1-, but not colonic α2-, and β-subunits of H+,K+-ATPase. Immunolabeling of an antibody specific to the α1 subunit was detected in type II, IV, and V fibrocytes distributed in the spiral ligament of the lateral wall and in the spiral limbus. Strong immunoreactivity was also found in the stria vascularis. Immunoelectron microscopic examination exhibited that the H+,K+-ATPase was localized exclusively at the basolateral site of strial marginal cells. Application of Sch-28080, a specific inhibitor of gastric H+,K+-ATPase, to the spiral ligament as well as to the stria vascularis caused prominent reduction of EP. These results may imply that the H+,K+-ATPase in the cochlear lateral wall is crucial for K+ circulation and thus plays a critical role in generation of EP.

scholarly journals Identification of Potential Meniere's Disease Targets in the Adult Stria Vascularis

2021 ◽  
Vol 12 ◽  
Author(s):  
Shoujun Gu ◽  
Rafal Olszewski ◽  
Lacey Nelson ◽  
Alvaro Gallego-Martinez ◽  
Jose Antonio Lopez-Escamez ◽  
...  
Keyword(s):  
Stria Vascularis ◽  
Ion Homeostasis ◽  
Cell Types ◽  
Meniere’S Disease ◽  
Endocochlear Potential ◽  
Menière’S Disease ◽  
Meniere's Disease ◽  
Ménière’S Disease ◽  
Menière's Disease ◽  
Ménière's Disease

The stria vascularis generates the endocochlear potential and is involved in processes that underlie ionic homeostasis in the cochlear endolymph, both which play essential roles in hearing. The histological hallmark of Meniere's disease (MD) is endolymphatic hydrops, which refers to the bulging or expansion of the scala media, which is the endolymph-containing compartment of the cochlea. This histologic hallmark suggests that processes that disrupt ion homeostasis or potentially endocochlear potential may underlie MD. While treatments exist for vestibular symptoms related to MD, effective therapies for hearing fluctuation and hearing loss seen in MD remain elusive. Understanding the potential cell types involved in MD may inform the creation of disease mouse models and provide insight into underlying mechanisms and potential therapeutic targets. For these reasons, we compare published datasets related to MD in humans with our previously published adult mouse stria vascularis single-cell and single-nucleus RNA-Seq datasets to implicate potentially involved stria vascularis (SV) cell types in MD. Finally, we provide support for these implicated cell types by demonstrating co-expression of select candidate genes for MD within SV cell types.

Long-Term Changes in Off-Lesion Endocochlear Potential after Induction of Localized Lesions in the Lateral Wall

2001 ◽  
Vol 110 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Rong Wu ◽  
Tomoyuki Hoshino
Keyword(s):  
Stria Vascularis ◽  
Green Light ◽  
Lateral Wall ◽  
Sudden Hearing Loss ◽  
Endocochlear Potential ◽  
Light Illumination ◽  
Morphological Examination ◽  
Damage Repair ◽  
Low Tone ◽  
Experimental Values

Localized lesions were produced in various turns of the guinea pig cochlea by means of a photochemical reaction between systemically administered rose bengal dye and green light illumination. The endocochlear potential (EP) was measured at various off-lesion sites, and a morphological examination was performed. In a previous study, this same investigation was done at 3 days, at which time all sites apical to the lesion showed significant EP depression, and damage to the stria vascularis at the lesion was ongoing. In the present 2-week study, the apical EP values were not different from the basal values, and all experimental values were essentially the same as the EP values found in control animals. Morphological examination revealed that the previously damaged structures were greatly repaired. Localized damage and early apical EP depression followed by damage repair and eventual EP recovery could account for the clinical course of certain cases of idiopathic sudden hearing loss involving low-tone deafness.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Cell Reactivity Pattern of the Guinea Pig Cecal Mucosa Evidenced by the ZIO Technique

1982 ◽  
Vol 40 ◽  
pp. 50-51
Author(s):  
Juan Mora-Galindo ◽  
Jorge Arauz-Contreras
Keyword(s):  
Guinea Pig ◽  
Phase Contrast ◽  
Osmium Tetroxide ◽  
Cell Types ◽  
Cell Reactivity ◽  
Transmission Electron ◽  
Neural Tissues ◽  
Maturation Stages ◽  
Zinc Iodide ◽  
Cecal Mucosa

The zinc iodide-osmium tetroxide (ZIO) technique is presently employed to study both, neural and non neural tissues. Precipitates depends on cell types and possibly cell metabol ism as well.Guinea pig cecal mucosa, already known to be composed of epithelium with cells at different maturation stages and lamina propria which i s formed by morphologically and functionally heterogeneous cell population, was studied to determine the pat tern of ZIO impregnation. For this, adult Guinea pg cecal mucosa was fixed with buffered 1.2 5% g 1 utara 1 dehyde before incubation with ZIO for 16 hours, a t 4°C in the dark. Further steps involved a quick sample dehydration in graded ethanols, embedding in Epon 812 and sectioning to observe the unstained material under a phase contrast light microscope (LM) and a transmission electron microscope (TEM).

scholarly journals Effects of Polyphenols in Tea (Camellia sinensis sp.) on the Modulation of Gut Microbiota in Human Trials and Animal Studies

2021 ◽  
Vol 12 (2) ◽  
pp. 202-216
Author(s):  
Mus Azza Suhana Khairudin ◽  
Abbe Maleyki Mhd Jalil ◽  
Napisah Hussin
Keyword(s):  
Gut Microbiota ◽  
Beta Diversity ◽  
Animal Studies ◽  
Tea Polyphenols ◽  
Microbiota Composition ◽  
Polyphenol Compounds ◽  
Human Trials ◽  
Diet Induced Obesity ◽  
Different Types ◽  
Meta Analyses

A diet high in polyphenols is associated with a diversified gut microbiome. Tea is the second most consumed beverage in the world, after water. The health benefits of tea might be attributed to the presence of polyphenol compounds such as flavonoids (e.g., catechins and epicatechins), theaflavins, and tannins. Although many studies have been conducted on tea, little is known of its effects on the trillions of gut microbiota. Hence, this review aimed to systematically study the effect of tea polyphenols on the stimulation or suppression of gut microbiota in humans and animals. It was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Articles were retrieved from PubMed and Scopus databases, and data were extracted from 6 human trials and 15 animal studies. Overall, large variations were observed in terms of microbiota composition between humans and animals. A more consistent pattern of diversified microbiota was observed in animal studies. Tea alleviated the gut microbiota imbalance caused by high-fat diet-induced obesity, diabetes, and ultraviolet-induced damage. The overall changes in microbiota composition measured by beta diversity analysis showed that tea had shifted the microbiota from the pattern seen in animals that received tea-free intervention. In humans, a prebiotic-like effect was observed toward the gut microbiota, but these results appeared in lower-quality studies. The beta diversity in human microbiota remains intact despite tea intervention; supplementation with different teas affects different types of bacterial taxa in the gut. These studies suggest that tea polyphenols may have a prebiotic effect in disease-induced animals and in a limited number of human interventions. Further intervention is needed to identify the mechanisms of action underlying the effects of tea on gut microbiota.

Sign in / Sign up

Export Citation Format

Share Document