The spiral ganglion and Rosenthal's canal in beluga whales.
Animals; Beluga Whale/*anatomy & histology; Cetacea; cochlea; Delphinapterus leucas; hearing; inner ear; Neurons/cytology; Odontoceti; Spiral Ganglion/*cytology
With the increase of human activity and corresponding increase in anthropogenic sounds in marine waters of the Arctic, it is necessary to understand its effect on the hearing of marine wildlife. We have conducted a baseline study on the spiral ganglion and Rosenthal's canal of the cochlea in beluga whales (Delphinapterus leucas) as an initial assessment of auditory anatomy and health. We present morphometric data on the length of the cochlea, number of whorls, neuron densities along its length, Rosenthal's canal length, and cross-sectional area, and show some histological results. In belugas, Rosenthal's canal is not a cylinder of equal cross-sectional area, but its cross-section is greatest near the apex of the basal whorl. We found systematic variation in the numbers of neurons along the length of the spiral ganglion, indicating that neurons are not dispersed evenly in Rosenthal's canal. These results provide data on functionally important structural parameters of the beluga ear. We observed no signs of acoustic trauma in our sample of beluga whales.
Sensor Jennifer D; Suydam Robert; George John C; Liberman M C; Lovano Denise; Rhaganti Mary Ann; Usip Sharon; Vinyard Christopher J; Thewissen J G M
Journal of morphology
2015
2015-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/jmor.20434" target="_blank" rel="noreferrer noopener">10.1002/jmor.20434</a>
Specific And Efficient Transduction Of Cochlear Inner Hair Cells With Recombinant Adeno-associated Virus Type 3 Vector
adeno-associated virus; adenovirus; Biotechnology & Applied Microbiology; cochlea; ear; Experimental Medicine; gene transfer; gene transfer; generation; Genetics & Heredity; guinea-pig cochlea; hair cells; in-vivo; promoter; rat; Research &; serotype; therapy; transgene expression
Recombinant adeno-associated virus (AAV) vectors are of interest for cochlear gene therapy because of their ability to mediate the efficient transfer and long-term stable expression of therapeutic genes in a wide variety of postmitotic tissues with minimal vector-related cytotoxicity. In the present study, seven AAV serotypes (AAV1-5, 7, 8) were used to construct vectors. The expression of EGFP by the chicken P-actin promoter associated with the cytomegalovirus immediate-early enhancer in cochlear cells showed that each of these serotypes successfully targets distinct cochlear cell types. In contrast to the other serotypes, the AAV3 vector specifically transduced cochlear inner hair cells with high efficiency in vivo, while the AAV1, 2, 5, 7, and 8 vectors also transduced these and other cell types, including spiral ganglion and spiral ligament cells. There was no loss of cochlear function with respect to evoked auditory brain-stem responses over the range of frequencies tested after the injection of AAV vectors. These findings are of value for further molecular studies of cochlear inner hair cells and for gene replacement strategies to correct recessive genetic hearing loss due to monogenic mutations in these cells.
Liu Y H; Okada T; Sheykholeslami K; Shimazaki K; Nomoto T; Muramatsu S I; Kanazawa T; Takeuchi K; Ajalli R; Mizukami H; Kume A; Ichimura K; Ozawa K
Molecular Therapy
2005
2005-10
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/j.ymthe.2005.03.021" target="_blank" rel="noreferrer noopener">10.1016/j.ymthe.2005.03.021</a>
Identification of Multiple Metabolic Enzymes from Mice Cochleae Tissue Using a Novel Functional Proteomics Technology
Animal tissues; Beef; Biology; cancer; cancer metabolism; cell metabolism; Cochlea; draft; Drug therapy; E coli; Electrophoresis; Elution; Enzymatic activity; Enzyme assays; Enzyme metabolism; Enzymes; Feasibility studies; Functional analysis; Gel electrophoresis; Genes; Genomics; Hearing impairment; Kinases; Mass spectrometry; Mass spectroscopy; medicine; messenger-rna; metabolism; mice; NAD(P)H oxidase; NADH; Neurobiology; Neurosciences; Nicotinamide adenine dinucleotide; Noise; Otolaryngology; Oxidation-reduction reactions; Phosphatase; Protein expression; proteins; Proteomes; Proteomics; Science & Technology - Other Topics; Sciences: Comprehensive Works; Scientific imaging; Studies; Substance abuse treatment; Technology; United States--US
A new type of technology in proteomics was developed in order to separate a complex protein mixture and analyze protein functions systematically. The technology combines the ability of two-dimensional gel electrophoresis (2-DE) to separate proteins with a protein elution plate (PEP) to recover active proteins for functional analysis and mass spectrometry (MS)-based identification. In order to demonstrate the feasibility of this functional proteomics approach, NADH and NADPH-dependent oxidases, major redox enzyme families, were identified from mice cochlear tissue after a specific drug treatment. By comparing the enzymatic activity between mice that were treated with a drug and a control group significant changes were observed. Using MS, five NADH-dependent oxidases were identified that showed highly altered enzymatic activities due to the drug treatment. In essence, the PEP technology allows for a systematic analysis of a large enzyme family from a complex proteome, providing insights in understanding the mechanism of drug treatment.
Wang D L; Li H; Liang R Q; Bao J X
PLOS ONE
2015
2015-03
Journal Article
<a href="http://doi.org/10.1371/journal.pone.0121826" target="_blank" rel="noreferrer noopener">10.1371/journal.pone.0121826</a>
Detection of single mRNAs in individual cells of the auditory system.
Cochlea; Immunohistochemistry; Inner hair cell; Outer hair cell; Single-molecule fluorescence in situ hybridization; Spiral ganglion neuron
Gene expression analysis is essential for understanding the rich repertoire of cellular functions. With the development of sensitive molecular tools such as single-cell RNA sequencing, extensive gene expression data can be obtained and analyzed from various tissues. Single-molecule fluorescence in situ hybridization (smFISH) has emerged as a powerful complementary tool for single-cell genomics studies because of its ability to map and quantify the spatial distributions of single mRNAs at the subcellular level in their native tissue. Here, we present a detailed method to study the copy numbers and spatial localizations of single mRNAs in the cochlea and inferior colliculus. First, we demonstrate that smFISH can be performed successfully in adult cochlear tissue after decalcification. Second, we show that the smFISH signals can be detected with high specificity. Third, we adapt an automated transcript analysis pipeline to quantify and identify single mRNAs in a cell-specific manner. Lastly, we show that our method can be used to study possible correlations between transcriptional and translational activities of single genes. Thus, we have developed a detailed smFISH protocol that can be used to study the expression of single mRNAs in specific cell types of the peripheral and central auditory systems.
Salehi Pezhman; Nelson Charlie N; Chen Yingying; Lei Debin; Crish Samuel D; Nelson Jovitha; Zuo Hongyan; Bao Jianxin
Hearing research
2018
2018-09
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.heares.2018.07.008" target="_blank" rel="noreferrer noopener">10.1016/j.heares.2018.07.008</a>
Conductive hearing loss during development does not appreciably alter the sharpness of cochlear tuning.
An increasing number of studies show that listeners often have difficulty hearing in situations with background noise, despite normal tuning curves in quiet. One potential source of this difficulty could be sensorineural changes in the auditory periphery (the ear). Signal in noise detection deficits also arise in animals raised with developmental conductive hearing loss (CHL), a manipulation that induces acoustic attenuation to model how sound deprivation changes the central auditory system. This model attributes perceptual deficits to central changes by assuming that CHL does not affect sensorineural elements in the periphery that could raise masked thresholds. However, because of efferent feedback, altering the auditory system could affect cochlear elements. Indeed, recent studies show that adult-onset CHL can cause cochlear synapse loss, potentially calling into question the assumption of an intact periphery in early-onset CHL. To resolve this issue, we tested the long-term peripheral effects of CHL via developmental bilateral malleus displacement. Using forward masking tuning curves, we compared peripheral tuning in animals raised with CHL vs age-matched controls. Using compound action potential measurements from the round window, we assessed inner hair cell synapse integrity. Results indicate that developmental CHL can cause minor synaptopathy. However, developmental CHL does not appreciably alter peripheral frequency tuning.
Ye Y; Ihlefeld A; Rosen MJ
Scientific Reports
2021
2021-02-17
Journal Artucle
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