Regulation of p27Kip1 by Sox2 Maintains Quiescence of Inner Pillar Cells in the Murine Auditory Sensory Epithelium

The sensory end organ of the ear, the organ of Corti, rests on a thin basilar membrane which lies between the bone of the central modiolus and the bony wall of the cochlea. In vivo, the organ of Corti is protected by the bony wall which totally surrounds it. In order to examine the sensory epithelium by scanning electron microscopy it is necessary to dissect away the protective bone and expose the region of interest (Fig. 1). This leaves the fragile organ of Corti susceptible to physical damage during subsequent handling. In our laboratory cochlear specimens, after dissection, are routinely prepared by the O-T- O-T-O technique, critical point dried and then lightly sputter coated with gold. This processing involves considerable specimen handling including several hours on a rotator during which the organ of Corti is at risk of being physically damaged. The following procedure uses low cost, readily available materials to hold the specimen during processing ,preventing physical damage while allowing an unhindered exchange of fluids.Following fixation, the cochlea is dehydrated to 70% ethanol then dissected under ethanol to prevent air drying. The holder is prepared by punching a hole in the flexible snap cap of a Wheaton vial with a paper hole punch. A small amount of two component epoxy putty is well mixed then pushed through the hole in the cap. The putty on the inner cap is formed into a “cup” to hold the specimen (Fig. 2), the putty on the outside is smoothed into a “button” to give good attachment even when the cap is flexed during handling (Fig. 3). The cap is submerged in the 70% ethanol, the bone at the base of the cochlea is seated into the cup and the sides of the cup squeezed with forceps to grip it (Fig.4). Several types of epoxy putty have been tried, most are either soluble in ethanol to some degree or do not set in ethanol. The only putty we find successful is “DUROtm MASTERMENDtm Epoxy Extra Strength Ribbon” (Loctite Corp., Cleveland, Ohio), this is a blue and yellow ribbon which is kneaded to form a green putty, it is available at many hardware stores.

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Faculty Opinions recommendation of Math1 regulates development of the sensory epithelium in the mammalian cochlea.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1022416.255626 ◽

2004 ◽

Author(s):

Guy Richardson

Keyword(s):

Sensory Epithelium

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Faculty Opinions recommendation of Non-cell-autonomous planar cell polarity propagation in the auditory sensory epithelium of vertebrates.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.9052956.9626054 ◽

2011 ◽

Author(s):

Andy Groves

Keyword(s):

Cell Polarity ◽

Planar Cell Polarity ◽

Sensory Epithelium

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Optimization of spectral-domain optical coherence tomography with a supercontinuum source for in vivo motion detection of low reflective outer hair cells in guinea pig cochleae

Optical Review ◽

10.1007/s10043-021-00654-8 ◽

2021 ◽

Author(s):

Fumiaki Nin ◽

Samuel Choi ◽

Takeru Ota ◽

Zhang Qi ◽

Hiroshi Hibino

Keyword(s):

Optical Coherence Tomography ◽

High Resolution ◽

Guinea Pig ◽

Hair Cells ◽

Sensory Epithelium ◽

Outer Hair Cells ◽

Acquisition Time ◽

Total Acquisition Time ◽

Sd Oct

AbstractSound evokes sub-nanoscale vibration within the sensory epithelium. The epithelium contains not only immotile cells but also contractile outer hair cells (OHCs) that actively shrink and elongate synchronously with the sound. However, the in vivo motion of OHCs has remained undetermined. The aim of this work is to perform high-resolution and -accuracy vibrometry in live guinea pigs with an SC-introduced spectral-domain optical coherence tomography system (SD-OCT). In this study, to reveal the effective contribution of SC source in the recording of the low reflective materials with the short total acquisition time, we compare the performances of the SC-introduced SD-OCT (SCSD-OCT) to that of the conventional SD-OCT. As inanimate comparison objects, we record a mirror, a piezo actuator, and glass windows. For the measurements in biological materials, we use in/ex vivo guinea pig cochleae. Our study achieved the optimization of a SD-OCT system for high-resolution in vivo vibrometry in the cochlear sensory epithelium, termed the organ of Corti, in mammalian cochlea. By introducing a supercontinuum (SC) light source and reducing the total acquisition time, we improve the axial resolution and overcome the difficulty in recording the low reflective material in the presence of biological noise. The high power of the SC source enables the system to achieve a spatial resolution of 1.72 ± 0.00 μm on a mirror and reducing the total acquisition time contributes to the high spatial accuracy of sub-nanoscale vibrometry. Our findings reveal the vibrations at the apical/basal region of OHCs and the extracellular matrix, basilar membrane.

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Morphological and Histological Features of the Vomeronasal Organ in African Pygmy Hedgehog (Atelerix albiventris)

Animals ◽

10.3390/ani11051462 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1462

Author(s):

Daisuke Kondoh ◽

Yusuke Tanaka ◽

Yusuke K. Kawai ◽

Takayuki Mineshige ◽

Kenichi Watanabe ◽

...

Keyword(s):

Soft Tissues ◽

Periodic Acid ◽

Vomeronasal Organ ◽

Sensory Epithelium ◽

Middle Part ◽

Periodic Acid Schiff ◽

Histological Features ◽

Duct Opening ◽

Hematoxylin Eosin ◽

Rostral Part

The vomeronasal organ (VNO) detects specific chemicals such as pheromones and kairomones. Hedgehogs (Eulipotyphla: Erinaceidae) have a well-developed accessory olfactory bulb that receives projections from the VNO, but little is known about the hedgehog VNO. Here, we studied the histological features of the VNO in five individual African pygmy hedgehogs by hematoxylin-eosin, periodic acid-Schiff, and Alcian blue stains. The hedgehog VNO comprises a hyaline cartilage capsule, soft tissue and epithelial lumen, and it branches from the site just before the incisive duct opening into the nasal cavity. The soft tissues contain several small mucous (or mucoserous) glands and a large serous gland, and many venous sinuses all around the lumen. The VNO lumen is round to oval throughout the hedgehog VNO, and the sensory epithelium lines almost the entire rostral part and medial wall of the middle part. These findings indicate that the VNO is functional and plays an important role in the hedgehog. Notably, the VNO apparently has a characteristic flushing mechanism with serous secretions like those of gustatory glands, which the hedgehog might frequently use to recognize the external environment.

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Hedgehog Signaling Governs the Development of Otic Sensory Epithelium and Its Associated Innervation in Zebrafish

Journal of Neuroscience ◽

10.1523/jneurosci.5109-09.2010 ◽

2010 ◽

Vol 30 (10) ◽

pp. 3612-3623 ◽

Cited By ~ 19

Author(s):

D. Sapede ◽

C. Pujades

Keyword(s):

Hedgehog Signaling ◽

Sensory Epithelium

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Preliminary biochemical characterization of the stereocilia and cuticular plate of hair cells of the chick cochlea.

The Journal of Cell Biology ◽

10.1083/jcb.109.4.1711 ◽

1989 ◽

Vol 109 (4) ◽

pp. 1711-1723 ◽

Cited By ~ 70

Author(s):

M S Tilney ◽

L G Tilney ◽

R E Stephens ◽

C Merte ◽

D Drenckhahn ◽

...

Keyword(s):

Hair Cells ◽

Actin Filaments ◽

Biochemical Characterization ◽

Cell Types ◽

Sensory Epithelium ◽

Tectorial Membrane ◽

Uncharacterized Protein ◽

Proteolytic Fragment ◽

Cuticular Plate ◽

Filament Bundles

The sensory epithelium of the chick cochlea contains only two cell types, hair cells and supporting cells. We developed methods to rapidly dissect out the sensory epithelium and to prepare a detergent-extracted cytoskeleton. High salt treatment of the cytoskeleton leaves a "hair border", containing actin filament bundles of the stereocilia still attached to the cuticular plate. On SDS-PAGE stained with silver the intact epithelium is seen to contain a large number of bands, the most prominent of which are calbindin and actin. Detergent extraction solubilizes most of the proteins including calbindin. On immunoblots antibodies prepared against fimbrin from chicken intestinal epithelial cells cross react with the 57- and 65-kD bands present in the sensory epithelium and the cytoskeleton. It is probable that the 57-kD is a proteolytic fragment of the 65-kD protein. Preparations of stereocilia attached to the overlying tectorial membrane contain the 57- and 65-kD bands. A 400-kD band is present in the cuticular plate. By immunofluorescence, fimbrin is detected in stereocilia but not in the hair borders after salt extraction. The prominent 125 A transverse stripping pattern characteristic of the actin cross-bridges in a bundle is also absent in hair borders suggesting fimbrin as the component that gives rise to the transverse stripes. Because the actin filaments in the stereocilia of hair borders still remain as compact bundles, albeit very disordered, there must be an additional uncharacterized protein besides fimbrin that cross-links the actin filaments together.

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Stem/Progenitor Cells Derived from the Cochlear Sensory Epithelium Give Rise to Spheres with Distinct Morphologies and Features

Journal of the Association for Research in Otolaryngology ◽

10.1007/s10162-009-0161-3 ◽

2009 ◽

Vol 10 (2) ◽

pp. 173-190 ◽

Cited By ~ 50

Author(s):

Marc Diensthuber ◽

Kazuo Oshima ◽

Stefan Heller

Keyword(s):

Progenitor Cells ◽

Sensory Epithelium

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The orienting response of Lake Michigan mottled sculpin is mediated by canal neuromasts

Journal of Experimental Biology ◽

10.1242/jeb.204.2.337 ◽

2001 ◽

Vol 204 (2) ◽

pp. 337-348 ◽

Cited By ~ 13

Author(s):

S. Coombs ◽

C.B. Braun ◽

B. Donovan

Keyword(s):

Time Course ◽

Lake Michigan ◽

Cell Damage ◽

Aminoglycoside Antibiotic ◽

Response Rates ◽

Orienting Response ◽

Sensory Epithelium ◽

Live Prey ◽

Mottled Sculpin ◽

Pre Treatment

Lake Michigan mottled sculpin, Cottus bairdi, exhibit a naturally occurring and unconditioned orienting response that can be triggered by both live prey and chemically inert vibrating spheres, even in blinded animals. CoCl(2)-induced reductions of the orienting response demonstrate that the lateral line is required for this behavior in the absence of non-mechanosensory cues (such as vision), but shed no light on the relative contributions of superficial and canal neuromasts to this behavior. To determine the relative roles of these two subsystems, we measured the frequency with which mottled sculpin oriented towards a small vibrating sphere before and after two treatments: (i) immersion of fish in a solution of gentamicin, an aminoglycoside antibiotic that damages hair cells in canal, but not superficial, neuromasts; and (ii) scraping the skin of the fish, which damages the superficial, but not the canal, neuromasts. To ensure that both superficial and canal neuromasts were adequately stimulated, we tested at different vibration frequencies (10 and 50 Hz) near or at the best frequency for each type of neuromast. At both test frequencies, response rates before treatment were greater than 70 % and were significantly greater than ‘spontaneous’ response frequencies measured in the absence of sphere vibration. Response rates fell to spontaneous levels after 1 day of gentamicin treatment and did not return to pre-treatment levels for 10–15 days. In contrast, response rates stayed approximately the same after superficial neuromasts had been damaged by skin abrasion. Scanning electron microscopy confirmed hair cell damage (loss of apical cilia) in canal, but not superficial, neuromasts of gentamicin-treated animals after as little as 24 h of treatment. The sensory epithelium of canal neuromasts gradually returned to normal, following a time course similar to behavioral loss and recovery of the orienting response, whereas that of superficial neuromasts appeared normal throughout the entire period. This study shows that the orienting response of the mottled sculpin is mediated by canal neuromasts.

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