Sample records for ear sensory cell

  1. Current concepts of hair cell differentiation and planar cell polarity in inner ear sensory organs.

    Sienknecht, Ulrike J


    Phylogenetically and ontogenetically, vertebrate development led to the generation of several inner ear sensory organs. During embryogenesis, cell fate specification determines whether each progenitor cell differentiates into a sensory hair cell or a supporting cell within the common sensory primordium. Finally, all sensory epithelia of the inner ear consist of a hair cell/supporting cell mosaic, albeit with anatomical differences depending on the sensory organ type. Hair cells develop a polarized bundle of stereovilli that is of functional importance for mechanotransduction. After initiating stereovillar development, hair cells align their bundles in a coordinated fashion, generating a characteristic hair cell orientation pattern, a process referred to as planar cell polarity (PCP). The pathway that controls PCP in the inner ear needs both to establish the development of a polarized morphology of the stereovillar bundle of the hair cell and to organize a systematic hair cell alignment. Because the hair cell orientation patterns of the various inner ear organs and vertebrate species differ fundamentally, it becomes apparent that in vertebrates, different aspects of PCP need to be independently controlled. In spite of important progress recently gained in the field of PCP research, we still need to identify the mechanisms (1) that initiate molecular asymmetries in cells, (2) that guide the transmission of polarity information from cell to cell, and (3) that consistently translate such polarity information into morphological asymmetries of hair cells.

  2. Artificial induction of Sox21 regulates sensory cell formation in the embryonic chicken inner ear.

    Stephen D Freeman

    Full Text Available During embryonic development, hair cells and support cells in the sensory epithelia of the inner ear derive from progenitors that express Sox2, a member of the SoxB1 family of transcription factors. Sox2 is essential for sensory specification, but high levels of Sox2 expression appear to inhibit hair cell differentiation, suggesting that factors regulating Sox2 activity could be critical for both processes. Antagonistic interactions between SoxB1 and SoxB2 factors are known to regulate cell differentiation in neural tissue, which led us to investigate the potential roles of the SoxB2 member Sox21 during chicken inner ear development. Sox21 is normally expressed by sensory progenitors within vestibular and auditory regions of the early embryonic chicken inner ear. At later stages, Sox21 is differentially expressed in the vestibular and auditory organs. Sox21 is restricted to the support cell layer of the auditory epithelium, while it is enriched in the hair cell layer of the vestibular organs. To test Sox21 function, we used two temporally distinct gain-of-function approaches. Sustained over-expression of Sox21 from early developmental stages prevented prosensory specification, and abolished the formation of both hair cells and support cells. However, later induction of Sox21 expression at the time of hair cell formation in organotypic cultures of vestibular epithelia inhibited endogenous Sox2 expression and Notch activity, and biased progenitor cells towards a hair cell fate. Interestingly, Sox21 did not promote hair cell differentiation in the immature auditory epithelium, which fits with the expression of endogenous Sox21 within mature support cells in this tissue. These results suggest that interactions among endogenous SoxB family transcription factors may regulate sensory cell formation in the inner ear, but in a context-dependent manner.

  3. Single-cell RNA-Seq resolves cellular complexity in sensory organs from the neonatal inner ear.

    Burns, Joseph C; Kelly, Michael C; Hoa, Michael; Morell, Robert J; Kelley, Matthew W


    In the inner ear, cochlear and vestibular sensory epithelia utilize grossly similar cell types to transduce different stimuli: sound and acceleration. Each individual sensory epithelium is composed of highly heterogeneous populations of cells based on physiological and anatomical criteria. However, limited numbers of each cell type have impeded transcriptional characterization. Here we generated transcriptomes for 301 single cells from the utricular and cochlear sensory epithelia of newborn mice to circumvent this challenge. Cluster analysis indicates distinct profiles for each of the major sensory epithelial cell types, as well as less-distinct sub-populations. Asynchrony within utricles allows reconstruction of the temporal progression of cell-type-specific differentiation and suggests possible plasticity among cells at the sensory-nonsensory boundary. Comparisons of cell types from utricles and cochleae demonstrate divergence between auditory and vestibular cells, despite a common origin. These results provide significant insights into the developmental processes that form unique inner ear cell types.

  4. HCN channels are not required for mechanotransduction in sensory hair cells of the mouse inner ear.

    Geoffrey C Horwitz

    Full Text Available The molecular composition of the hair cell transduction channel has not been identified. Here we explore the novel hypothesis that hair cell transduction channels include HCN subunits. The HCN family of ion channels includes four members, HCN1-4. They were originally identified as the molecular correlates of the hyperpolarization-activated, cyclic nucleotide gated ion channels that carry currents known as If, IQ or Ih. However, based on recent evidence it has been suggested that HCN subunits may also be components of the elusive hair cell transduction channel. To investigate this hypothesis we examined expression of mRNA that encodes HCN1-4 in sensory epithelia of the mouse inner ear, immunolocalization of HCN subunits 1, 2 and 4, uptake of the transduction channel permeable dye, FM1-43 and electrophysiological measurement of mechanotransduction current. Dye uptake and transduction current were assayed in cochlear and vestibular hair cells of wildtype mice exposed to HCN channel blockers or a dominant-negative form of HCN2 that contained a pore mutation and in mutant mice that lacked HCN1, HCN2 or both. We found robust expression of HCNs 1, 2 and 4 but little evidence that localized HCN subunits in hair bundles, the site of mechanotransduction. Although high concentrations of the HCN antagonist, ZD7288, blocked 50-70% of the transduction current, we found no reduction of transduction current in either cochlear or vestibular hair cells of HCN1- or HCN2- deficient mice relative to wild-type mice. Furthermore, mice that lacked both HCN1 and HCN2 also had normal transduction currents. Lastly, we found that mice exposed to the dominant-negative mutant form of HCN2 had normal transduction currents as well. Taken together, the evidence suggests that HCN subunits are not required for mechanotransduction in hair cells of the mouse inner ear.

  5. Cisplatin Ototoxicity Blocks Sensory Regeneration in the Avian Inner Ear

    Slattery, Eric L.; Warchol, Mark E.


    Cisplatin is a chemotherapeutic agent that is widely-used in the treatment of solid tumors. Ototoxicity is a common side effect of cisplatin therapy, and often leads to permanent hearing loss. The sensory organs of the avian ear are able to regenerate hair cells after aminoglycoside ototoxicity. This regenerative response is mediated by supporting cells, which serve as precursors to replacement hair cells. Given the antimitotic properties of cisplatin, we examined whether the avian ear was also capable of regeneration after cisplatin ototoxicity. Using cell and organ cultures of the chick cochlea and utricle, we found that cisplatin treatment caused apoptosis of both auditory and vestibular hair cells. Hair cell death in the cochlea occurred in a unique pattern, progressing from the low frequency (distal) region toward the high frequency (proximal) region. We also found that cisplatin caused a dose-dependent reduction in the proliferation of cultured supporting cells as well as increased apoptosis in those cells. As a result, we observed no recovery of hair cells after ototoxic injury caused by cisplatin. Finally, we explored the potential for nonmitotic hair cell recovery via activation of Notch pathway signaling. Treatment with the γ-secretase inhibitor DAPT failed to promote the direct transdifferentiation of supporting cells into hair cells in cisplatin-treated utricles. Taken together, our data show that cisplatin treatment causes maintained changes to inner ear supporting cells and severely impairs the ability of the avian ear to regenerate either via proliferation or by direct transdifferentiation. PMID:20203207

  6. The Notch ligand JAG1 is required for sensory progenitor development in the mammalian inner ear.

    Amy E Kiernan


    Full Text Available In mammals, six separate sensory regions in the inner ear are essential for hearing and balance function. Each sensory region is made up of hair cells, which are the sensory cells, and their associated supporting cells, both arising from a common progenitor. Little is known about the molecular mechanisms that govern the development of these sensory organs. Notch signaling plays a pivotal role in the differentiation of hair cells and supporting cells by mediating lateral inhibition via the ligands Delta-like 1 and Jagged (JAG 2. However, another Notch ligand, JAG1, is expressed early in the sensory patches prior to cell differentiation, indicating that there may be an earlier role for Notch signaling in sensory development in the ear. Here, using conditional gene targeting, we show that the Jag1 gene is required for the normal development of all six sensory organs within the inner ear. Cristae are completely lacking in Jag1-conditional knockout (cko mutant inner ears, whereas the cochlea and utricle show partial sensory development. The saccular macula is present but malformed. Using SOX2 and p27kip1 as molecular markers of the prosensory domain, we show that JAG1 is initially expressed in all the prosensory regions of the ear, but becomes down-regulated in the nascent organ of Corti by embryonic day 14.5, when the cells exit the cell cycle and differentiate. We also show that both SOX2 and p27kip1 are down-regulated in Jag1-cko inner ears. Taken together, these data demonstrate that JAG1 is expressed early in the prosensory domains of both the cochlear and vestibular regions, and is required to maintain the normal expression levels of both SOX2 and p27kip1. These data demonstrate that JAG1-mediated Notch signaling is essential during early development for establishing the prosensory regions of the inner ear.

  7. BMP4 signaling is involved in the generation of inner ear sensory epithelia

    Wang Yucheng


    Full Text Available Abstract Background The robust expression of BMP4 in the incipient sensory organs of the inner ear suggests possible roles for this signaling protein during induction and development of auditory and vestibular sensory epithelia. Homozygous BMP4-/- animals die before the inner ear's sensory organs develop, which precludes determining the role of BMP4 in these organs with simple gene knockout experiments. Results Here we use a chicken otocyst culture system to perform quantitative studies on the development of inner ear cell types and show that hair cell and supporting cell generation is remarkably reduced when BMP signaling is blocked, either with its antagonist noggin or by using soluble BMP receptors. Conversely, we observed an increase in the number of hair cells when cultured otocysts were treated with exogenous BMP4. BMP4 treatment additionally prompted down-regulation of Pax-2 protein in proliferating sensory epithelial progenitors, leading to reduced progenitor cell proliferation. Conclusion Our results implicate BMP4 in two events during chicken inner ear sensory epithelium formation: first, in inducing the switch from proliferative sensory epithelium progenitors to differentiating epithelial cells and secondly, in promoting the differentiation of hair cells within the developing sensory epithelia.

  8. The candidate splicing factor Sfswap regulates growth and patterning of inner ear sensory organs.

    Yalda Moayedi


    Full Text Available The Notch signaling pathway is thought to regulate multiple stages of inner ear development. Mutations in the Notch signaling pathway cause disruptions in the number and arrangement of hair cells and supporting cells in sensory regions of the ear. In this study we identify an insertional mutation in the mouse Sfswap gene, a putative splicing factor, that results in mice with vestibular and cochlear defects that are consistent with disrupted Notch signaling. Homozygous Sfswap mutants display hyperactivity and circling behavior consistent with vestibular defects, and significantly impaired hearing. The cochlea of newborn Sfswap mutant mice shows a significant reduction in outer hair cells and supporting cells and ectopic inner hair cells. This phenotype most closely resembles that seen in hypomorphic alleles of the Notch ligand Jagged1 (Jag1. We show that Jag1; Sfswap compound mutants have inner ear defects that are more severe than expected from simple additive effects of the single mutants, indicating a genetic interaction between Sfswap and Jag1. In addition, expression of genes involved in Notch signaling in the inner ear are reduced in Sfswap mutants. There is increased interest in how splicing affects inner ear development and function. Our work is one of the first studies to suggest that a putative splicing factor has specific effects on Notch signaling pathway members and inner ear development.

  9. The candidate splicing factor Sfswap regulates growth and patterning of inner ear sensory organs.

    Moayedi, Yalda; Basch, Martin L; Pacheco, Natasha L; Gao, Simon S; Wang, Rosalie; Harrison, Wilbur; Xiao, Ningna; Oghalai, John S; Overbeek, Paul A; Mardon, Graeme; Groves, Andrew K


    The Notch signaling pathway is thought to regulate multiple stages of inner ear development. Mutations in the Notch signaling pathway cause disruptions in the number and arrangement of hair cells and supporting cells in sensory regions of the ear. In this study we identify an insertional mutation in the mouse Sfswap gene, a putative splicing factor, that results in mice with vestibular and cochlear defects that are consistent with disrupted Notch signaling. Homozygous Sfswap mutants display hyperactivity and circling behavior consistent with vestibular defects, and significantly impaired hearing. The cochlea of newborn Sfswap mutant mice shows a significant reduction in outer hair cells and supporting cells and ectopic inner hair cells. This phenotype most closely resembles that seen in hypomorphic alleles of the Notch ligand Jagged1 (Jag1). We show that Jag1; Sfswap compound mutants have inner ear defects that are more severe than expected from simple additive effects of the single mutants, indicating a genetic interaction between Sfswap and Jag1. In addition, expression of genes involved in Notch signaling in the inner ear are reduced in Sfswap mutants. There is increased interest in how splicing affects inner ear development and function. Our work is one of the first studies to suggest that a putative splicing factor has specific effects on Notch signaling pathway members and inner ear development.

  10. Inner ear supporting cells: rethinking the silent majority.

    Wan, Guoqiang; Corfas, Gabriel; Stone, Jennifer S


    Sensory epithelia of the inner ear contain two major cell types: hair cells and supporting cells. It has been clear for a long time that hair cells play critical roles in mechanoreception and synaptic transmission. In contrast, until recently the more abundant supporting cells were viewed as serving primarily structural and homeostatic functions. In this review, we discuss the growing information about the roles that supporting cells play in the development, function and maintenance of the inner ear, their activities in pathological states, their potential for hair cell regeneration, and the mechanisms underlying these processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Otx1 null mutant mice show partial segregation of sensory epithelia comparable to lamprey ears

    Fritzsch, B.; Signore, M.; Simeone, A.


    We investigated the development of inner ear innervation in Otx1 null mutants, which lack a horizontal canal, between embryonic day 12 (E12) and postnatal day 7 (P7) with DiI and immunostaining for acetylated tubulin. Comparable to control animals, horizontal crista-like fibers were found to cross over the utricle in Otx1 null mice. In mutants these fibers extend toward an area near the endolymphatic duct, not to a horizontal crista. Most Otx1 null mutants had a small patch of sensory hair cells at this position. Measurement of the area of the utricular macula suggested it to be enlarged in Otx1 null mutants. We suggest that parts of the horizontal canal crista remain incorporated in the utricular sensory epithelium in Otx1 null mutants. Other parts of the horizontal crista appear to be variably segregated to form the isolated patch of hair cells identifiable by the unique fiber trajectory as representing the horizontal canal crista. Comparison with lamprey ear innervation reveals similarities in the pattern of innervation with the dorsal macula, a sensory patch of unknown function. SEM data confirm that all foramina are less constricted in Otx1 null mutants. We propose that Otx1 is not directly involved in sensory hair cell formation of the horizontal canal but affects the segregation of the horizontal canal crista from the utricle. It also affects constriction of the two main foramina in the ear, but not their initial formation. Otx1 is thus causally related to horizontal canal morphogenesis as well as morphogenesis of these foramina.

  12. BMP4 Signaling is Involved in the Generation of Inner Ear Sensory Epithelia

    Wang Yucheng; Zhao Yanling; Wang Zhengmin; Corrales Carleton E; Li Huawei; Liu Hong; Heller Stefan


    Abstract Background The robust expression of BMP4 in the incipient sensory organs of the inner ear suggests possible roles for this signaling protein during induction and development of auditory and vestibular sensory epithelia. Homozygous BMP4-/- animals die before the inner ear's sensory organs develop, which precludes determining the role of BMP4 in these organs with simple gene knockout experiments. Results Here we use a chicken otocyst culture system to perform quantitative studies on th...

  13. Early transcriptional response to aminoglycoside antibiotic suggests alternate pathways leading to apoptosis of sensory hair cells in the mouse inner ear

    Neil eSegil


    Full Text Available Aminoglycoside antibiotics are the drug of choice for treating many bacterial infections, but their administration results in hearing loss in nearly one fourth of the patients who receive them. Several biochemical pathways have been implicated in aminoglycoside antibiotic ototoxicity; however, little is known about how hair cells respond to aminoglycoside antibiotics at the transcriptome level. Here we have investigated the genome-wide response to the aminoglycoside antibiotic gentamicin. Using organotypic cultures of the perinatal organ of Corti, we performed RNA sequencing using cDNA libraries obtained from FACS-purified hair cells. Within 3 hours of gentamicin treatment, the messenger RNA level of more than three thousand genes in hair cells changed significantly. Bioinformatic analysis of these changes highlighted several known signal transduction pathways, including the JNK pathway and the NF-κB pathway, in addition to genes involved in the stress response, apoptosis, cell cycle control, and DNA damage repair. In contrast, only 698 genes, mainly involved in cell cycle and metabolite biosynthetic processes, were significantly affected in the non-hair cell population. The gene expression profiles of hair cells in response to gentamicin share a considerable similarity with those previously observed in gentamicin-induced nephrotoxicity. Our findings suggest that previously observed early responses to gentamicin in hair cells in specific signaling pathways are reflected in changes in gene expression. Additionally, the observed changes in gene expression of cell cycle regulatory genes indicate a disruption of the postmitotic state, which may suggest an alternative pathway regulating gentamicin-induced hair cell death. This work provides a more comprehensive view of aminoglycoside antibiotic ototoxicity, and thus contribute to identifying potential pathways or therapeutic targets to alleviate this important side effect of aminoglycoside

  14. The progenitors of inner ear hair cells and their regulating genes

    SHU Wei-ning; ZHAO Li-dong; ZHANG Xiao-bing; YANG Shi-ming


    @@ Hair cells in the mammalian inner ear are very fragile and are often injured as a result of acoustic trauma or exposure to ototoxic drugs (cisplatin, aminoglycosides, etc)[1]. In amphibians and birds, spontaneous post-injury regeneration of all inner ear sensory hair cell occurs, while in the mammalian cochlea, such hearing loss is usually permanent as there are currently no treatments that can lead to post-injury hair cell regeneration.

  15. Signaling regulating inner ear development: cell fate determination, patterning, morphogenesis, and defects.

    Nakajima, Yuji


    The membranous labyrinth of the inner ear is a highly complex organ that detects sound and balance. Developmental defects in the inner ear cause congenital hearing loss and balance disorders. The membranous labyrinth consists of three semicircular ducts, the utricle, saccule, and endolymphatic ducts, and the cochlear duct. These complex structures develop from the simple otic placode, which is established in the cranial ectoderm adjacent to the neural crest at the level of the hindbrain at the early neurula stage. During development, the otic placode invaginates to form the otic vesicle, which subsequently gives rise to neurons for the vestibulocochlear ganglion, the non-sensory and sensory epithelia of the membranous labyrinth that includes three ampullary crests, two maculae, and the organ of Corti. Combined paracrine and autocrine signals including fibroblast growth factor, Wnt, retinoic acid, hedgehog, and bone morphogenetic protein regulate fate determination, axis formation, and morphogenesis in the developing inner ear. Juxtacrine signals mediated by Notch pathways play a role in establishing the sensory epithelium, which consists of mechanosensory hair cells and supporting cells. The highly differentiated organ of Corti, which consists of uniformly oriented inner/outer hair cells and specific supporting cells, develops during fetal development. Developmental alterations/arrest causes congenital malformations in the inner ear in a spatiotemporal-restricted manner. A clearer understanding of the mechanisms underlying inner ear development is important not only for the management of patients with congenital inner ear malformations, but also for the development of regenerative therapy for impaired function.

  16. A Review of Gene Delivery and Stem Cell Based Therapies for Regenerating Inner Ear Hair Cells

    Michael S. Detamore


    Full Text Available Sensory neural hearing loss and vestibular dysfunction have become the most common forms of sensory defects, affecting millions of people worldwide. Developing effective therapies to restore hearing loss is challenging, owing to the limited regenerative capacity of the inner ear hair cells. With recent advances in understanding the developmental biology of mammalian and non-mammalian hair cells a variety of strategies have emerged to restore lost hair cells are being developed. Two predominant strategies have developed to restore hair cells: transfer of genes responsible for hair cell genesis and replacement of missing cells via transfer of stem cells. In this review article, we evaluate the use of several genes involved in hair cell regeneration, the advantages and disadvantages of the different viral vectors employed in inner ear gene delivery and the insights gained from the use of embryonic, adult and induced pluripotent stem cells in generating inner ear hair cells. Understanding the role of genes, vectors and stem cells in therapeutic strategies led us to explore potential solutions to overcome the limitations associated with their use in hair cell regeneration.

  17. Planar cell polarity in the inner ear: how do hair cells acquire their oriented structure?

    Lewis, Julian; Davies, Alex


    Sensory hair cells in the ear and lateral line have an asymmetrical hair-bundle structure, essential for their function as directional mechanotransducers. We examine four questions: (1) how does the planar asymmetry of the individual hair cell originate? (2) How are the orientations of neighboring hair cells coordinated? (3) How is the orientation of a group of hair cells controlled in relation to the ear as a whole? (4) How does the initial cell asymmetry lead to creation of the asymmetrical hair bundle? Studies of the development of hairs and bristles in Drosophila, combined with genetic data from vertebrates, suggest that the answer to questions (1) and (2) lies in asymmetries that develop at the cell cortex and at cell-cell junctions, generated by products of a set of primary planar cell polarity genes, including the transmembrane receptor Frizzled. A separate and largely independent mechanism controls asymmmetric allocation of cell fate determinants such as Numb at mitosis, in Drosophila and possibly in the ear also. Little is known about long-range signals that might orient hair cells globally in the ear, but progress has been made in identifying a set of genes responsible for read-out of the primary polarity specification. These genes, in flies and vertebrates, provide a link to assembly of the polarized cytoskeleton; myosin VIIA appears to belong in this group. The mechanism creating the staircase pattern of stereocilium lengths is unknown, but could involve regulation of stereocilium growth by Ca(2+) ions entering via transduction channels.

  18. Adenovirus Vectors Target Several Cell Subtypes of Mammalian Inner Ear In Vivo

    Li, Wenyan; Shen, Jun


    Mammalian inner ear harbors diverse cell types that are essential for hearing and balance. Adenovirus is one of the major vectors to deliver genes into the inner ear for functional studies and hair cell regeneration. To identify adenovirus vectors that target specific cell subtypes in the inner ear, we studied three adenovirus vectors, carrying a reporter gene encoding green fluorescent protein (GFP) from two vendors or with a genome editing gene Cre recombinase (Cre), by injection into postnatal days 0 (P0) and 4 (P4) mouse cochlea through scala media by cochleostomy in vivo. We found three adenovirus vectors transduced mouse inner ear cells with different specificities and expression levels, depending on the type of adenoviral vectors and the age of mice. The most frequently targeted region was the cochlear sensory epithelium, including auditory hair cells and supporting cells. Adenovirus with GFP transduced utricular supporting cells as well. This study shows that adenovirus vectors are capable of efficiently and specifically transducing different cell types in the mammalian inner ear and provides useful tools to study inner ear gene function and to evaluate gene therapy to treat hearing loss and vestibular dysfunction. PMID:28116172

  19. Sensory hair cell death and regeneration in fishes

    Jerry D. Monroe


    Full Text Available Sensory hair cells are specialized mechanotransductive receptors required for hearing and vestibular function. Loss of hair cells in humans and other mammals is permanent and causes reduced hearing and balance. In the early 1980’s, it was shown that hair cells continue to be added to the inner ear sensory epithelia in cartilaginous and bony fishes. Soon thereafter, hair cell regeneration was documented in the chick cochlea following acoustic trauma. Since then, research using chick and other avian models has led to great insights into hair cell death and regeneration. However, with the rise of the zebrafish as a model organism for studying disease and developmental processes, there has been an increased interest in studying sensory hair cell death and regeneration in its lateral line and inner ears. Advances derived from studies in zebrafish and other fish species include understanding the effect of ototoxins on hair cells and finding otoprotectants to mitigate ototoxin damage, the role of cellular proliferation versus direct transdifferentiation during hair cell regeneration, and elucidating cellular pathways involved in the regeneration process. This review will summarize research on hair cell death and regeneration using fish models, indicate the potential strengths and weaknesses of these models, and discuss several emerging areas of future studies.

  20. Calcium Gradients in the Fish inner Ear sensory Epithelium and otolithic Membrane: an Energy filtering Transmission electron Microscopy (EFTEM) Study

    Ibsch, M.; Anken, R.; Rahmann, H.

    Inner ear otolith formation in fish is supposed to be performed by the molecular release of proteinacious precursor material from the sensory epithelia, followed by an undirected and diffuse precipitation of calcium carbonate (which is mainly responsible for the functionally important weight of otoliths). Previous experiments have shown, however, that otolith formation in terms of provision both of the protein matrix and of calcium is regulated by a (likely neuronal) feedback mechanism. This regulating mechanism effects a symmetrical crystallisation of the corresponding otoliths in the inner ears of both sides of the head, which is necessary for a correct graviperception and for maintenance of postural control; thus, asymmetrical otoliths can induce kinetoses (e.g., space motion sickness) both in human and fish. On the background of an obviously directed incorporation of calcium into otoliths, the site of origin of the otoliths's inorganic components such as calcium still remains obscure. Therefore, ultrastructural and element analytical investigations were undertaken to screen the calcium distribution within the macular epithelial region using fish as model system. Electron spectroscopic imaging (ESI) and electron energy loss spectra (EELS) revealed discrete calcium-precipitations in the extracellular space of the otolithic membrane as well as within the lumina of the epithelial sensory cells. The calcium particles were accumulated at the macular tight junctions and seemed to be distributed in an ascending intracellular and a descending extracellular gradient towards the otolith. Further distinct calcium containing crystals covered the peripheral proteinacious layer of the otolith. The remaining endolymphatic space of the otocyst was lacking calcium precipitates. Overall, the present results indicate that the apical region of the macular epithelium is involved in the controlled release of calcium. This finding is in complete agreement with a study using calcium

  1. Investigating Science Student Teachers' Ideas about Function and Anatomical Form of Two Human Sensory Organs, the Eye and the Ear

    Kunt, Halil


    The purpose of this research was to determine science student teachers' level of knowledge about the anatomical structure of two sensory organs, the eye and the ear, in addition to vision and hearing processes. Conducted with 86 science student teachers, research utilized drawing methods and open-ended questions as data collection instruments. The…

  2. Ultrastructural aspects of otoliths and sensory epithelia of fish inner ear exposed to hypergravity

    Ibsch, M.; Nindl, G.; Anken, R. H.; Körtje, K. H.; Rahmann, H.

    The present electron microscopical investigations were directed to the question, whether alterations in the gravitational force might induce structural changes in the morphology of otoliths or/and inner ear sensory epithelia of developing and adult swordtail fish (Xiphophorus helleri) that had been kept either under long-term moderate hypergravity (8 days; 3g) or under short-time extreme hypergravity (10 minutes up to 9g). The otoliths of adult and neonate swordtail fish were investigated by means of scanning electron microscopy (SEM). Macular epithelia of adult fish were examined both by SEM and transmission electron microscopy (TEM). The saccular otoliths (sagittae) of normally hatched adult fish revealed an enormous inter- (and even intra-; i.e. left vs. right) individual diversity in shape and size, whereas the otoliths of utricles (lapilli) and lagenae (asterisci) seemed to be more constant regarding morphological parameters. The structural diversity of juvenile otoliths was found to be less prominent as compared to the adults, differing from the latter regarding their peculiar crystalline morphology. Qualitative differences in the fine structure (SEM) of otoliths taken from adult and larval animals kept under 3g in comparison to 1g controls could not be observed. The SEM and TEM investigations of sensory epithelia also did not reveal any effects due to 3g stimulation. Even extreme hypergravity (more than 7g) for 10 minutes did not result in distinct pathological changes.

  3. Sensory-evoked turning locomotion in red-eared turtles: kinematic analysis and electromyography.

    Welch, Dan B; Currie, Scott N


    We examined the limb kinematics and motor patterns that underlie sensory-evoked turning locomotion in red-eared turtles. Intact animals were held by a band-clamp in a water-filled tank. Turn-swimming was evoked by slowly rotating turtles to the right or left via a motor connected to the shaft of the band-clamp. Animals executed sustained forward turn-swimming against the direction of the imposed rotation. We recorded video of turn-swimming and computer-analyzed the limb and head movements. In a subset of turtles, we also recorded electromyograms from identified limb muscles. Turning exhibited a stereotyped pattern of (1) coordinated forward swimming in the hindlimb and forelimb on the outer side of the turn, (2) back-paddling in the hindlimb on the inner side, (3) a nearly stationary, "braking" forelimb on the inner side, and (4) neck bending toward the direction of the turn. Reversing the rotation caused animals to switch the direction of their turns and the asymmetric pattern of right and left limb activities. Preliminary evidence suggested that vestibular inputs were sufficient to drive the behavior. Sensory-evoked turning may provide a useful experimental platform to examine the brainstem commands and spinal neural networks that underlie the activation and switching of different locomotor forms.

  4. Molecular evolution of the vertebrate mechanosensory cell and ear

    Fritzsch, Bernd; Beisel, Kirk W.; Pauley, Sarah; Soukup, Garrett


    The molecular basis of mechanosensation, mechanosensory cell development and mechanosensory organ development is reviewed with an emphasis on its evolution. In contrast to eye evolution and development, which apparently modified a genetic program through intercalation of genes between the master control genes on the top (Pax6, Eya1, Six1) of the hierarchy and the structural genes (rhodopsin) at the bottom, the as yet molecularly unknown mechanosensory channel precludes such a firm conclusion for mechanosensors. However, recent years have seen the identification of several structural genes which are involved in mechanosensory tethering and several transcription factors controlling mechanosensory cell and organ development; these warrant the interpretation of available data in very much the same fashion as for eye evolution: molecular homology combined with potential morphological parallelism. This assertion of molecular homology is strongly supported by recent findings of a highly conserved set of microRNAs that appear to be associated with mechanosensory cell development across phyla. The conservation of transcription factors and their regulators fits very well to the known or presumed mechanosensory specializations which can be mostly grouped as variations of a common cellular theme. Given the widespread distribution of the molecular ability to form mechanosensory cells, it comes as no surprise that structurally different mechanosensory organs evolved in different phyla, presenting a variation of a common theme specified by a conserved set of transcription factors in their cellular development. Within vertebrates and arthropods, some mechanosensory organs evolved into auditory organs, greatly increasing sensitivity to sound through modifications of accessory structures to direct sound to the specific sensory epithelia. However, while great attention has been paid to the evolution of these accessory structures in vertebrate fossils, comparatively less attention has

  5. A simple method for purification of vestibular hair cells and non-sensory cells, and application for proteomic analysis.

    Herget, Meike; Scheibinger, Mirko; Guo, Zhaohua; Jan, Taha A; Adams, Christopher M; Cheng, Alan G; Heller, Stefan


    Mechanosensitive hair cells and supporting cells comprise the sensory epithelia of the inner ear. The paucity of both cell types has hampered molecular and cell biological studies, which often require large quantities of purified cells. Here, we report a strategy allowing the enrichment of relatively pure populations of vestibular hair cells and non-sensory cells including supporting cells. We utilized specific uptake of fluorescent styryl dyes for labeling of hair cells. Enzymatic isolation and flow cytometry was used to generate pure populations of sensory hair cells and non-sensory cells. We applied mass spectrometry to perform a qualitative high-resolution analysis of the proteomic makeup of both the hair cell and non-sensory cell populations. Our conservative analysis identified more than 600 proteins with a false discovery rate of Analysis of proteins exclusively detected in either population revealed 64 proteins that were specific to hair cells and 103 proteins that were only detectable in non-sensory cells. Statistical analyses extended these groups by 53 proteins that are strongly upregulated in hair cells versus non-sensory cells and vice versa by 68 proteins. Our results demonstrate that enzymatic dissociation of styryl dye-labeled sensory hair cells and non-sensory cells is a valid method to generate pure enough cell populations for flow cytometry and subsequent molecular analyses.

  6. Aminoglycoside-induced hair cell death of inner ear organs causes functional deficits in adult zebrafish (Danio rerio.

    Phillip M Uribe

    Full Text Available Aminoglycoside antibiotics, like gentamicin, kill inner ear sensory hair cells in a variety of species including chickens, mice, and humans. The zebrafish (Danio rerio has been used to study hair cell cytotoxicity in the lateral line organs of larval and adult animals. Little is known about whether aminoglycosides kill the hair cells within the inner ear of adult zebrafish. We report here the ototoxic effects of gentamicin on hair cells in the saccule, the putative hearing organ, and utricle of zebrafish. First, adult zebrafish received a single 30 mg/kg intraperitoneal injection of fluorescently-tagged gentamicin (GTTR to determine the distribution of gentamicin within inner ear sensory epithelia. After 4 hours, GTTR was observed in hair cells throughout the saccular and utriclar sensory epithelia. To assess the ototoxic effects of gentamicin, adult zebrafish received a single 250 mg/kg intraperitoneal injection of gentamicin and, 24 hours later, auditory evoked potential recordings (AEPs revealed significant shifts in auditory thresholds compared to untreated controls. Zebrafish were then euthanized, the inner ear fixed, and labeled for apoptotic cells (TUNEL reaction, and the stereociliary bundles of hair cells labeled with fluorescently-tagged phalloidin. Whole mounts of the saccule and utricle were imaged and cells counted. There were significantly more TUNEL-labeled cells found in both organs 4 hours after gentamicin injection compared to vehicle-injected controls. As expected, significantly fewer hair cell bundles were found along the rostral-caudal axis of the saccule and in the extrastriolar and striolar regions of the utricle in gentamicin-treated animals compared to untreated controls. Therefore, as in other species, gentamicin causes significant inner ear sensory hair cell death and auditory dysfunction in zebrafish.

  7. Evolution of vertebrate mechanosensory hair cells and inner ears: toward identifying stimuli that select mutation driven altered morphologies.

    Fritzsch, Bernd; Straka, Hans


    Among the major distance senses of vertebrates, the ear is unique in its complex morphological changes during evolution. Conceivably, these changes enable the ear to adapt toward sensing various physically well-characterized stimuli. This review develops a scenario that integrates sensory cell with organ evolution. We propose that molecular and cellular evolution of the vertebrate hair cells occurred prior to the formation of the vertebrate ear. We previously proposed that the genes driving hair cell differentiation were aggregated in the otic region through developmental re-patterning that generated a unique vertebrate embryonic structure, the otic placode. In agreement with the presence of graviceptive receptors in many vertebrate outgroups, it is likely that the vertebrate ear originally functioned as a simple gravity-sensing organ. Based on the rare occurrence of angular acceleration receptors in vertebrate outgroups, we further propose that the canal system evolved with a more sophisticated ear morphogenesis. This evolving morphogenesis obviously turned the initial otocyst into a complex set of canals and recesses, harboring multiple sensory epithelia each adapted to the acquisition of a specific aspect of a given physical stimulus. As support for this evolutionary progression, we provide several details of the molecular basis of ear development.

  8. Cell- and gene-therapy approaches to inner ear repair

    Conde de Felipe, Magnolia; Feijoo-Redondo, Ana; García-Sancho, Javier; Schimmang, Thomas; Durán, Mercedes


    Sensorineural hearing loss is the most common sensory disorder in humans. It is primarily due to the degeneration of highly specialised mechanosensory cells in the cochlea, the so-called hair cells. Hearing problems can also be caused or further aggravated by the death of auditory sensory neurons that convey the information from the hair cells to the brain stem. Despite the discovery of stem/progenitor cells in the mammalian cochlea, no regeneration of either damaged hair cells or auditory ne...

  9. Applications for single cell trajectory analysis in inner ear development and regeneration.

    Durruthy-Durruthy, Robert; Heller, Stefan


    Single cell trajectory analysis is a computational approach that orders cells along a pseudotime axis. This temporal modeling approach allows the characterization of transitional processes such as lineage development, response to insult, and tissue regeneration. The concept can also be applied to resolve spatial organization of cells within the originating tissue. Known as temporal and spatial transcriptomics, respectively, these methods belong to the most powerful analytical techniques for quantitative gene expression data currently available. Here, we discuss three different approaches: principal component analysis, the 'Monocle' algorithm, and self-organizing maps. We use a previously published qRT-PCR dataset of single neuroblast cells isolated from the developing mouse inner ear to highlight the basic features of the three methods and their individual limitations, as well as the distinct advantages that make them useful for research on the inner ear. The complex developmental morphogenesis of the inner ear and its specific challenges such as the paucity of cells as well as important open questions such as sensory hair cell regeneration render this organ a prime target for single cell trajectory analysis strategies.

  10. Downstream targets of GATA3 in the vestibular sensory organs of the inner ear.

    Alvarado, David M; Veile, Rose; Speck, Judith; Warchol, Mark; Lovett, Michael


    Haploinsufficiency for the transcription factor GATA3 leads to hearing loss in humans. It is expressed throughout the auditory sensory epithelium (SE). In the vestibular organs, GATA3 is limited to the striola reversal zone of the utricle. Stereocilia orientation shifts 180 degrees at this region, which contains morphologically distinct type-I hair cells. The striola is conserved in all amniotes, its function is unknown, and GATA3 is the only known marker of the reversal zone. To identify downstream targets of GATA3 that might point to striolar function, we measured gene expression differences between striolar and extra-striolar SE. These were compared with profiles after GATA3 RNAi and GATA3 over-expression. We identified four genes (BMP2, FKHL18, LMO4, and MBNL2) that consistently varied with GATA3. Two of these (LMO4 and MBNL2) were shown to be direct targets of GATA3 by ChIP. Our results suggest that GATA3 impacts WNT signaling in this region of the sensory macula.

  11. Distribution of neurosensory progenitor pools during inner ear morphogenesis unveiled by cell lineage reconstruction

    Dyballa, Sylvia; Savy, Thierry; Germann, Philipp; Mikula, Karol; Remesikova, Mariana; Špir, Róbert; Zecca, Andrea; Peyriéras, Nadine; Pujades, Cristina


    Reconstructing the lineage of cells is central to understanding how the wide diversity of cell types develops. Here, we provide the neurosensory lineage reconstruction of a complex sensory organ, the inner ear, by imaging zebrafish embryos in vivo over an extended timespan, combining cell tracing and cell fate marker expression over time. We deliver the first dynamic map of early neuronal and sensory progenitor pools in the whole otic vesicle. It highlights the remodeling of the neuronal progenitor domain upon neuroblast delamination, and reveals that the order and place of neuroblasts’ delamination from the otic epithelium prefigure their position within the SAG. Sensory and non-sensory domains harbor different proliferative activity contributing distinctly to the overall growth of the structure. Therefore, the otic vesicle case exemplifies a generic morphogenetic process where spatial and temporal cues regulate cell fate and functional organization of the rudiment of the definitive organ. DOI: PMID:28051766

  12. Ear manipulations reveal a critical period for survival and dendritic development at the single-cell level in Mauthner neurons.

    Elliott, Karen L; Houston, Douglas W; DeCook, Rhonda; Fritzsch, Bernd


    Second-order sensory neurons are dependent on afferents from the sense organs during a critical period in development for their survival and differentiation. Past research has mostly focused on whole populations of neurons, hampering progress in understanding the mechanisms underlying these critical phases. To move toward a better understanding of the molecular and cellular basis of afferent-dependent neuronal development, we developed a new model to study the effects of ear removal on a single identifiable cell in the hindbrain of a frog, the Mauthner cell. Ear extirpation at various stages of Xenopus laevis development defines a critical period of progressively-reduced dependency of Mauthner cell survival/differentiation on the ear afferents. Furthermore, ear removal results in a progressively decreased reduction in the number of dendritic branches. Conversely, addition of an ear results in an increase in the number of dendritic branches. These results suggest that the duration of innervation and the number of inner ear afferents play a quantitative role in Mauthner cell survival/differentiation, including dendritic development.

  13. Cutaneous Squamous Cell Carcinoma with Invasion through Ear Cartilage

    Julie Boisen


    Full Text Available Cutaneous squamous cell carcinoma of the ear represents a high-risk tumor location with an increased risk of metastasis and local tissue invasion. However, it is uncommon for these cancers to invade through nearby cartilage. Cartilage invasion is facilitated by matrix metalloproteases, specifically collagenase 3. We present the unusual case of a 76-year-old man with an auricular squamous cell carcinoma that exhibited full-thickness perforation of the scapha cartilage. Permanent sections through the eroded cartilage confirmed tumor invasion extending to the posterior ear skin.

  14. Primary T-cell lymphoblastic lymphoma in the middle ear.

    Li, Bo; Liu, Shixi; Yang, Hui; Wang, Weiya


    T-cell lymphoblastic lymphoma (T-LBL) is a highly aggressive lymphoma characterized by precursor T-cell malignancy and lymphadenopathy or mediastinal involvement. We present the case of an 11-year-old boy with a diagnosis of middle ear T-LBL, which manifested as a headache, hearing loss and peripheral facial paralysis. The child was given intensive chemotherapy and had a complete response. To our knowledge, this is the first case reported in the literature of T-LBL originating in the middle ear. This case aims to help clinicians to be vigilant about the possibility of primary lesions at atypical sites in some special diseases.

  15. Evolution of a sensory novelty: tympanic ears and the associated neural processing

    Christensen-Dalsgaard, Jakob; Carr, Catherine E


    Tympanic hearing is a true evolutionary novelty that appears to have developed independently in at least five major tetrapod groups-the anurans, turtles, lepidosaurs, archosaurs and mammals. The emergence of a tympanic ear would have increased the frequency range and sensitivity of hearing...... sensitivity and directionality at low frequencies. Therefore, tetrapod auditory processing may originally have been organized into low- and high-frequency streams, where only the high-frequency processing was mediated by tympanic input. The closure of the middle ear cavity in mammals and some birds...

  16. Middle ear mucosal regeneration with three-dimensionally tissue-engineered autologous middle ear cell sheets in rabbit model.

    Yaguchi, Yuichiro; Murakami, Daisuke; Yamato, Masayuki; Hama, Takanori; Yamamoto, Kazuhisa; Kojima, Hiromi; Moriyama, Hiroshi; Okano, Teruo


    The likelihood of recurrent retraction and adhesion of newly formed tympanic membrane is high when middle ear mucosa is extensively lost during cholesteatoma and adhesive otitis media surgery. If rapid postoperative regeneration of the mucosa on the exposed bone surface can be achieved, prevention of recurrent eardrum adhesion and cholesteatoma formation, for which there has been no definitive treatment, can be expected. Suture-less transplantation of tissue-engineered mucosal cell sheets was examined immediately after the operation of otitis media surgery in order to quickly regenerate middle ear mucosa lost during surgery in a rabbit model. Transplantable middle ear mucosal cell sheets with a three-dimensional tissue architecture very similar to native middle ear mucosa were fabricated from middle ear mucosal tissue fragments obtained in an autologous manner from middle ear bulla on temperature-responsive culture surfaces. Immediately after the mucosa was resected from middle ear bone bulla inner cavity, mucosal cell sheets were grafted at the resected site. Both bone hyperplasia and granulation tissue formation were inhibited and early mucosal regeneration was observed in the cell sheet-grafted group, compared with the control group in which only mucosal removal was carried out and the bone surface exposed. This result indicates that tissue engineered mucosal cell sheets would be useful to minimize complications after the surgical operation on otitis media and future clinical application is expected.

  17. A dog with squamous cell carcinoma in the middle ear.

    Yoshikawa, Hiroto; Mayer, Monique N; Linn, Kathleen A; Dickinson, Ryan M; Carr, Anthony P


    An 8-year-old, castrated male golden retriever was referred for lethargy and inappetance. Severe pain was elicited on palpation of the left temporomandibular joint region. Computed tomography revealed aggressive bone destruction of the left bulla. Squamous cell carcinoma was diagnosed. Malignant tumor in the canine middle ear is rare.

  18. A dog with squamous cell carcinoma in the middle ear

    YOSHIKAWA, Hiroto; Mayer, Monique N.; Linn, Kathleen A.; Dickinson, Ryan M.; Carr, Anthony P.


    An 8-year-old, castrated male golden retriever was referred for lethargy and inappetance. Severe pain was elicited on palpation of the left temporomandibular joint region. Computed tomography revealed aggressive bone destruction of the left bulla. Squamous cell carcinoma was diagnosed. Malignant tumor in the canine middle ear is rare.

  19. Glutamate-induced production of nitric oxide in guinea pig vestibular sensory cells.

    Takumida, M; Anniko, M


    Glutamate-induced production of nitric oxide (NO) in the vestibular organ of the guinea pig was investigated using the new fluorescence indicator, DAF-2DA, for direct detection of NO. Utricular maculae and isolated vestibular sensory cells were examined to locate NO production sites. The fluorescence intensity of the sensory cells was augmented by stimulation with glutamate, NMDA and AMPA. This is the first direct evidence of NO production in the vestibular end organs. NO may play an important role in the glutamate-induced ototoxicity and also be involved in disease of the inner ear.

  20. CD44 is a marker for the outer pillar cells in the early postnatal mouse inner ear.

    Hertzano, Ronna; Puligilla, Chandrakala; Chan, Siaw-Lin; Timothy, Caroline; Depireux, Didier A; Ahmed, Zubair; Wolf, Jeffrey; Eisenman, David J; Friedman, Thomas B; Riazuddin, Sheikh; Kelley, Matthew W; Strome, Scott E


    Cluster of differentiation antigens (CD proteins) are classically used as immune cell markers. However, their expression within the inner ear is still largely undefined. In this study, we explored the possibility that specific CD proteins might be useful for defining inner ear cell populations. mRNA expression profiling of microdissected auditory and vestibular sensory epithelia revealed 107 CD genes as expressed in the early postnatal mouse inner ear. The expression of 68 CD genes was validated with real-time RT-PCR using RNA extracted from microdissected sensory epithelia of cochleae, utricles, saccules, and cristae of newborn mice. Specifically, CD44 was identified as preferentially expressed in the auditory sensory epithelium. Immunohistochemistry revealed that within the early postnatal organ of Corti, the expression of CD44 is restricted to outer pillar cells. In order to confirm and expand this finding, we characterized the expression of CD44 in two different strains of mice with loss- and gain-of-function mutations in Fgfr3 which encodes a receptor for FGF8 that is essential for pillar cell development. We found that the expression of CD44 is abolished from the immature pillar cells in homozygous Fgfr3 knockout mice. In contrast, both the outer pillar cells and the aberrant Deiters' cells in the Fgfr3 ( P244R/ ) (+) mice express CD44. The deafness phenotype segregating in DFNB51 families maps to a linkage interval that includes CD44. To study the potential role of CD44 in hearing, we characterized the auditory system of CD44 knockout mice and sequenced the entire open reading frame of CD44 of affected members of DFNB51 families. Our results suggest that CD44 does not underlie the deafness phenotype of the DFNB51 families. Finally, our study reveals multiple potential new cell type-specific markers in the mouse inner ear and identifies a new marker for outer pillar cells.

  1. Ongoing cell death and immune influences on regeneration in the vestibular sensory organs

    Warchol, M. E.; Matsui, J. I.; Simkus, E. L.; Ogilive, J. M.


    Hair cells in the vestibular organs of birds have a relatively short life span. Mature hair cells appear to die spontaneously and are then quickly replaced by new hair cells that arise from the division of epithelial supporting cells. A similar regenerative mechanism also results in hair cell replacement after ototoxic damage. The cellular basis of hair cell turnover in the avian ear is not understood. We are investigating the signaling pathways that lead to hair cell death and the relationship between ongoing cell death and cell production. In addition, work from our lab and others has demonstrated that the avian inner ear contains a resident population of macrophages and that enhanced numbers of macrophages are recruited to sites of hair cells lesions. Those observations suggest that macrophages and their secretory products (cytokines) may be involved in hair cell regeneration. Consistent with that suggestion, we have found that treatment with the anti-inflammatory drug dexamethasone reduces regenerative cell proliferation in the avian ear, and that certain macrophage-secreted cytokines can influence the proliferation of vestibular supporting cells and the survival of statoacoustic neurons. Those results suggest a role for the immune system in the process of sensory regeneration in the inner ear.

  2. MicroRNA-183 Family in Inner Ear: Hair Cell Development and Deafness.

    Mahmoodian Sani, Mohammad Reza; Hashemzadeh-Chaleshtori, Morteza; Saidijam, Massoud; Jami, Mohammad-Saeid; Ghasemi-Dehkordi, Payam


    miRNAs are essential factors of an extensively conserved post-transcriptional process controlling gene expression at mRNA level. Varoius biological processes such as growth and differentiation are regulated by miRNAs. Web of Science and PubMed databases were searched using the Endnote software for the publications about the role miRNA-183 family in inner ear: hair cell development and deafness published from 2000 to 2016. A triplet of these miRNAs particularly the miR-183 family is highly expressed in vertebrate hair cells, as with some of the peripheral neurosensory cells. Point mutations in one member of this family, miR-96, underlie DFNA50 autosomal deafness in humans and lead to abnormal hair cell development and survival in mice. In zebrafish, overexpression of the miR-183 family induces extra and ectopic hair cells, while knockdown decreases the number of hair cell. The miR-183 family (miR-183, miR-96 and miR-182) is expressed abundantly in some types of sensory cell in the eye, nose and inner ear. In the inner ear, mechanosensory hair cells have a robust expression level. Despite much similarity of these miRs sequences, small differences lead to distinct targeting of messenger RNAs targets. In the near future, miRNAs are likely to be explored as potential therapeutic agents to repair or regenerate hair cells, cell reprogramming and regenerative medicine applications in animal models because they can simultaneously down-regulate dozens or even hundreds of transcripts.

  3. Effects of Scopolamine on Blood Vessels in Rabbit Ear after Sympathetic and Sensory Denervation

    刘书勤; 臧伟进; 成亮; 李增利; 于晓江; 李宝平


    Objectives To investigate the effects and involved mechanisms of scopolamine (Scop) on rabbit ear blood vessels. Methods Rabbit ear blood vessels were desympathetic and desensory innervation with surgical operation. Diameters of dorsal auricular arterial trunks in vivo were measured with a pair of compasses and the ruler in a dissecting microscope, and effluents from isolated ear under constant perfusion pressure were recorded with a digital drop-recorder. Results Intramuscular injection of Scop 0.1 mg/kg made the diameter of denerved dorsal auricular arterial trunks, as well as that of innerved ones, significantly increased. Scop by itself, at the maximal concentration (Cmax) of 3 μM, 30 μM and 300 μM, did not alter the effluent flow from the isolated denervated rabbit ear, but chlorpromazine (CPZ), at Cmax of 1 μM, acetylcholine (ACh), 0.25μM, all significantly increased the effluent flow, and norepinephrine (NE), 0.1μM, significantly decreased the effluent. Scop, 3 μM, did not affect ACh (0.25μM)-induced the increase of effluent flow, but Scop,30μM, alleviated the increase. Scop, 3μM, did not affect NE (0.1 μM)-induced the decrease of effluent flow, but Scop, 10, 30 and 100 μM, significantly alleviated the decrease. Conclusions The study suggests that Scop has no direct vasodilator effect. The vasodilator effect of Scop is not due to the blockade of muscarinic receptor. However, Scop can dilate blood vessels contracted by α1-adrenoceptor activation.

  4. Pattern of hair cell loss and delayed peripheral neuron degeneration in inner ear by a high-dose intratympanic gentamicin

    Jintao Yu; Dalian Ding; Fengjun Wang; Haiyan Jiang; Hong Sun; Richard Salvi


    To gain insights into the ototoxic effects of aminoglycoside antibiotics (AmAn) and delayed peripheral ganglion neuron death in the inner ear, experimental animal models were widely used with several different approaches including AmAn systemic injections, combination treat-ment of AmAn and diuretics, or local application of AmAn. In these approaches, systemic AmAn treatment alone usually causes incomplete damage to hair cells in the inner ear. Co-administration of diuretic and AmAn can completely destroy the cochlear hair cells, but it is impossible to damage the vestibular system. Only the approach of AmAn local application can selectively eliminate most sensory hair cells in the inner ear. Therefore, AmAn local application is more suitable for studies for complete hair cell destructions in cochlear and vestibular system and the following delayed peripheral ganglion neuron death. In current studies, guinea pigs were unilaterally treated with a high concentration of gentamicin (GM, 40 mg/ml) through the tympanic membrane into the middle ear cavity. Auditory functions and vestibular functions were measured before and after GM treatment. The loss of hair cells and delayed degeneration of ganglion neurons in both cochlear and vestibular system were quantified 30 days or 60 days after treatment. The results showed that both auditory and vestibular functions were completely abolished after GM treatment. The sensory hair cells were totally missing in the cochlea, and severely destroyed in vestibular end-organs. The delayed spiral ganglion neuron death 60 days after the deafening procedure was over 50%. However, no obvious pathological changes were observed in vestibular ganglion neurons 60 days post-treatment. These results indicated that a high concentration of gentamycin delivered to the middle ear cavity can destroy most sensory hair cells in the inner ear that subsequently causes the delayed spiral ganglion neuron degeneration. This model might be useful for studies

  5. Dimethyl sulfoxide (DMSO) exacerbates cisplatin-induced sensory hair cell death in zebrafish (Danio rerio).

    Uribe, Phillip M; Mueller, Melissa A; Gleichman, Julia S; Kramer, Matthew D; Wang, Qi; Sibrian-Vazquez, Martha; Strongin, Robert M; Steyger, Peter S; Cotanche, Douglas A; Matsui, Jonathan I


    Inner ear sensory hair cells die following exposure to aminoglycoside antibiotics or chemotherapeutics like cisplatin, leading to permanent auditory and/or balance deficits in humans. Zebrafish (Danio rerio) are used to study drug-induced sensory hair cell death since their hair cells are similar in structure and function to those found in humans. We developed a cisplatin dose-response curve using a transgenic line of zebrafish that expresses membrane-targeted green fluorescent protein under the control of the Brn3c promoter/enhancer. Recently, several small molecule screens have been conducted using zebrafish to identify potential pharmacological agents that could be used to protect sensory hair cells in the presence of ototoxic drugs. Dimethyl sulfoxide (DMSO) is typically used as a solvent for many pharmacological agents in sensory hair cell cytotoxicity assays. Serendipitously, we found that DMSO potentiated the effects of cisplatin and killed more sensory hair cells than treatment with cisplatin alone. Yet, DMSO alone did not kill hair cells. We did not observe the synergistic effects of DMSO with the ototoxic aminoglycoside antibiotic neomycin. Cisplatin treatment with other commonly used organic solvents (i.e. ethanol, methanol, and polyethylene glycol 400) also did not result in increased cell death compared to cisplatin treatment alone. Thus, caution should be exercised when interpreting data generated from small molecule screens since many compounds are dissolved in DMSO.

  6. Inner ear hair cells deteriorate in mice engineered to have no or diminished innervation.

    Jennifer eKersigo


    Full Text Available The innervation of the inner ear critically depends on the two neurotrophins Ntf3 and Bdnf. In contrast to this molecularly well established dependency, evidence regarding the need of innervation for long-term maintenance of inner ear hair cells is inconclusive due to experimental variability. Mutant mice that lack both neurotrophins could shed light on the long-term consequences of innervation loss on hair cells without introducing experimental variability, but do not survive after birth. Mutant mice with conditional deletion of both neurotrophins lose almost all innervation by postnatal day 10 and show an initially normal development of hair cells by this stage. No innervation remains after three weeks and complete loss of all innervation results in near complete loss of outer and many inner hair cells of the organ of Corti within 4 months. Mutants that retain one allele of either neurotrophin have only partial loss of innervation of the organ of Corti and show a longer viability of cochlear hair cells with more profound loss of inner hair cells. Ultimately, however, hair cells disappear with a base to apex progression, proportional to the residual density of innervation and similar to carboplatin ototoxicity. Similar to reports of hair cell loss after aminoglycoside treatment, blobbing of stereocilia of apparently dying hair cells protrude into the cochlear duct. Denervation of vestibular sensory epithelia for several months also resulted in variable results, ranging from unusual hair cells resembling the aberrations found in the organ of Corti, to near normal hair cells in the canal cristae. Fusion and/or resorption of stereocilia and loss of hair cells follows a pattern reminiscent of Myo6 and Cdc42 null mice. Our data support a role of innervation for long-term maintenance but with a remarkable local variation that needs to be taken into account when attempting regeneration of the organ of Corti.

  7. Shaping the mammalian auditory sensory organ by the planar cell polarity pathway.

    Kelly, Michael; Chen, Ping


    The human ear is capable of processing sound with a remarkable resolution over a wide range of intensity and frequency. This ability depends largely on the extraordinary feats of the hearing organ, the organ of Corti and its sensory hair cells. The organ of Corti consists of precisely patterned rows of sensory hair cells and supporting cells along the length of the snail-shaped cochlear duct. On the apical surface of each hair cell, several rows of actin-containing protrusions, known as stereocilia, form a "V"-shaped staircase. The vertices of all the "V"-shaped stereocilia point away from the center of the cochlea. The uniform orientation of stereocilia in the organ of Corti manifests a distinctive form of polarity known as planar cell polarity (PCP). Functionally, the direction of stereociliary bundle deflection controls the mechanical channels located in the stereocilia for auditory transduction. In addition, hair cells are tonotopically organized along the length of the cochlea. Thus, the uniform orientation of stereociliary bundles along the length of the cochlea is critical for effective mechanotransduction and for frequency selection. Here we summarize the morphological and molecular events that bestow the structural characteristics of the mammalian hearing organ, the growth of the snail-shaped cochlear duct and the establishment of PCP in the organ of Corti. The PCP of the sensory organs in the vestibule of the inner ear will also be described briefly.

  8. Hair cell bundles: flexoelectric motors of the inner ear.

    Kathryn D Breneman

    Full Text Available Microvilli (stereocilia projecting from the apex of hair cells in the inner ear are actively motile structures that feed energy into the vibration of the inner ear and enhance sensitivity to sound. The biophysical mechanism underlying the hair bundle motor is unknown. In this study, we examined a membrane flexoelectric origin for active movements in stereocilia and conclude that it is likely to be an important contributor to mechanical power output by hair bundles. We formulated a realistic biophysical model of stereocilia incorporating stereocilia dimensions, the known flexoelectric coefficient of lipid membranes, mechanical compliance, and fluid drag. Electrical power enters the stereocilia through displacement sensitive ion channels and, due to the small diameter of stereocilia, is converted to useful mechanical power output by flexoelectricity. This motor augments molecular motors associated with the mechanosensitive apparatus itself that have been described previously. The model reveals stereocilia to be highly efficient and fast flexoelectric motors that capture the energy in the extracellular electro-chemical potential of the inner ear to generate mechanical power output. The power analysis provides an explanation for the correlation between stereocilia height and the tonotopic organization of hearing organs. Further, results suggest that flexoelectricity may be essential to the exquisite sensitivity and frequency selectivity of non-mammalian hearing organs at high auditory frequencies, and may contribute to the "cochlear amplifier" in mammals.

  9. Peripheral sensory cells in the cephalic sensory organs of Lymnaea stagnalis.

    Wyeth, Russell C; Croll, Roger P


    The peripheral nervous system in gastropods plays a key role in the neural control of behaviors, but is poorly studied in comparison with the central nervous system. Peripheral sensory neurons, although known to be widespread, have been studied in a patchwork fashion across several species, with no comprehensive treatment in any one species. We attempted to remedy this limitation by cataloging peripheral sensory cells in the cephalic sensory organs of Lymnaea stagnalis employing backfills, vital stains, histochemistry, and immunohistochemistry. By using at least two independent methods to corroborate observations, we mapped four different cell types. We have found two different populations of bipolar sensory cells that appear to contain catecholamines(s) and histamine, respectively. Each cell had a peripheral soma, an epithelial process bearing cilia, and a second process projecting to the central nervous system. We also found evidence for two populations of nitric oxide-producing sensory cells, one bipolar, probably projecting centrally, and the second unipolar, with only a single epithelial process and no axon. The various cell types are presumably either mechanosensory or chemosensory, but the complexity of their distributions does not allow formation of hypotheses regarding modality. In addition, our observations indicate that yet more peripheral sensory cell types are present in the cephalic sensory organs of L. stagnalis. These results are an important step toward linking sensory cell morphology to modality. Moreover, our observations emphasize the size of the peripheral nervous system in gastropods, and we suggest that greater emphasis be placed on understanding its role in gastropod neuroethology.

  10. In vitro differentiation of mouse embryonic stem cells into inner ear hair cell-like cells using stromal cell conditioned medium.

    Ouji, Y; Ishizaka, S; Nakamura-Uchiyama, F; Yoshikawa, M


    Hearing loss is mainly caused by loss of sensory hair cells (HCs) in the organ of Corti or cochlea. Although embryonic stem (ES) cells are a promising source for cell therapy, little is known about the efficient generation of HC-like cells from ES cells. In the present study, we developed a single-medium culture method for growing embryoid bodies (EBs), in which conditioned medium (CM) from cultures of ST2 stromal cells (ST2-CM) was used for 14-day cultures of 4-day EBs. At the end of the 14-day cultures, up to 20% of the cells in EB outgrowths expressed HC-related markers, including Math1 (also known as Atoh1), myosin6, myosin7a, calretinin, α9AchR and Brn3c (also known as Pou4f3), and also showed formation of stereocilia-like structures. Further, we found that these cells were incorporated into the developing inner ear after transplantation into chick embryos. The present inner ear HC induction method using ST2-CM (HIST2 method) is quite simple and highly efficient to obtain ES-derived HC-like cells with a relatively short cultivation time.

  11. Cloned goats (Capra hircus) from adult ear cells

    GUO; Jitong(郭继彤); AN; Zhixing(安志兴); LI; Yu(李煜); LI; Xuefeng(李雪峰); LI; Yuqiang(李裕强); GUO; Zekun(郭泽坤); ZHANG; Yong(张涌)


    The average number of available oocytes recovered per ovary collected during the breeding season in dairy goats was 5.5 (1815/330). 66.17% (1201/1815) of oocytes extruded the first polar body after maturation in vitro for 20 h. 75.44% (906/1201) of matured oocytes with membrane evagination around the MⅡchromosomes were enucleated. Ear skin fibroblast cells were derived from an adult female Jining Grey goat (C. hircus). The cells were cryopreserved in liquid nitrogen after passage 2. Thawed cells were further cultured for 3-6 passages and were subjected to serum starvation by 0.5% FBS for 2-10 d, then used as donor cells for nuclear transfer. 98.12% (889/906) of the enucleated oocytes were reconstructed by intracytoplasmic injection of karyoplast. The reconstructed embryos were activated by 5 μmol/L ionomycin for 4.5 min and further activated by culturing with 6-dimethylaminopurine (6-DMAP) for 3 h. After 36 h of culture in mCR1aaBF, 76.69% (645/841) of the cloned embryos cleaved. There were no significant differences in development in vitro between the cloned embryos derived from donor cells precooled at 4℃ for 24 h and nonprecooled donor cells. The cleavage rates, 4-cell development, and blastocyst development of reconstructed embryos were 72.48% (79/109), 53.16% (42/79), and 19.05% (8/42) in precooled group; 68.5% (211/308), 59.72% (126/211), and 17.46% (22/126) in nonprecooled group, respectively. Eighteen cloned 4-cell embryos derived from precooled donor cells were transferred and one cloned kid was born. Eighty-four cloned 4-cell embryos derived from nonprecooled donor cells were transferred and no offspring were produced. Of 18 cloned morale from nonprecooled donor cells transferred, one kid was born. The results of microsatellite DNA analyses indicated that the two cloned kids were from the same donor fibroblast cell line derived from an adult goat ear skin.

  12. Ear Infection (Middle Ear)

    Ear infection (middle ear) Overview By Mayo Clinic Staff An ear infection (acute otitis media) is most often a bacterial or viral infection that affects the middle ear, the air-filled space behind the eardrum that ...

  13. Optimizing cell sourcing for clinical translation of tissue engineered ears.

    Morrison, Kerry A; Cohen, Benjamin P; Asanbe, Ope; Dong, Xue; Harper, Alice; Bonassar, Lawrence J; Spector, Jason A


    Background . Currently, the major impediment to clinical translation of our previously described platform for the fabrication of high fidelity, patient-specific tissue engineered ears is the development of a clinically optimal cell sourcing strategy. A limited autologous auricular chondrocyte (AuC) supply in conjunction with rapid chondrocyte de-differentiation during in vitro expansion currently makes clinical translation more challenging. Mesenchymal stem cells (MSCs) offer significant promise due to their inherent chondrogenic potential, and large availability through minimally invasive procedures. Herein, we demonstrate the promise of AuC/MSC co-culture to fabricate elastic cartilage using 50% fewer AuC than standard approaches. Bovine auricular chondrocytes (bAuC) and bovine MSC (bMSC) were encapsulated within 10 mg ml(-1) type I collagen hydrogels in ratios of bAuC:bMSC 100:0, 50:50, and 0:100 at a density of 25 million cells ml(-1) hydrogel. One mm thick collagen sheet gels were fabricated, and thereafter, 8 mm diameter discs were extracted using a biopsy punch. Discs were implanted subcutaneously in the dorsa of nude mice (NU/NU) and harvested after 1 and 3 months. Gross analysis of explanted discs revealed bAuC:bMSC co-culture discs maintained their size and shape, and exhibited native auricular cartilage-like elasticity after 1 and 3 months of implantation. Co-culture discs developed into auricular cartilage, with viable chondrocytes within lacunae, copious proteoglycan and elastic fiber deposition, and a distinct perichondrial layer. Biochemical analysis confirmed that co-culture discs deposited critical cartilage molecular components more readily than did both bAuC and bMSC discs after 1 and 3 months, and proteoglycan content significantly increased between 1 and 3 months. We have successfully demonstrated an innovative cell sourcing strategy that facilitates our efforts to achieve clinical translation of our high fidelity, patient-specific ears for

  14. Directional cell movements downstream of Gbx2 and Otx2 control the assembly of sensory placodes

    Ben Steventon


    Full Text Available Cranial placodes contribute to sensory structures including the inner ear, the lens and olfactory epithelium and the neurons of the cranial sensory ganglia. At neurula stages, placode precursors are interspersed in the ectoderm surrounding the anterior neural plate before segregating into distinct placodes by as yet unknown mechanisms. Here, we perform live imaging to follow placode progenitors as they aggregate to form the lens and otic placodes. We find that while placode progenitors move with the same speed as their non-placodal neighbours, they exhibit increased persistence and directionality and these properties are required to assemble morphological placodes. Furthermore, we demonstrate that these factors are components of the transcriptional networks that coordinate placode cell behaviour including their directional movements. Together with previous work, our results support a dual role for Otx and Gbx transcription factors in both the early patterning of the neural plate border and the later segregation of its derivatives into distinct placodes.

  15. Degenerative hairlets on the vestibular sensory cells in mutant bustling (BUS/Idr) mice.

    Moriyama, K; Hashimoto, R; Hanai, A; Yoshizaki, N; Yonezawa, S; Otani, H


    The bustling mouse (BUS/Idr: bus) is a mutant mouse strain which exhibits deafness, bustling/hyperkinetic behaviour and functional disorders seemingly related to the vestibular system. This phenotype develops in homozygous (bus/bus) mice and has been shown from cross experiments to be genetically induced by a single autosomal recessive gene. We previously detected, with light and electron microscopy, post-natal degeneration of the inner ear sensory cells in homozygotes. In the present study, we examined, by electron microscopy, the development of pathological changes in the sensory epithelia of the macula acustica and crista ampullaris of homozygous mice of various ages, paying special attention to the detailed morphology of the sensory hairlets. The homozygous mice exhibited specific pathological changes: a decrease in the number of hairs; disarrangement of the kinocilium-stereocilia pattern; and, fused and/or very large stereocilia. Homozygotes also frequently exhibited apical cytoplasmic herniation, or bleb of hair cells, as well as a degenerated kinocilium in the sensory epithelium. Heterozygotes showed similar changes, but to a lesser degree and frequency. As for the vestibular organs, similar pathological changes had developed at day, 17 of gestation. These pathological findings and onset suggest that the BUS mouse may be a mutant mouse strain distinct from other reported strains which display similar behaviour, and may be a useful animal model for the study of human degenerative vestibular disorders.

  16. The inner ear produces a natriuretic hormone

    Qvortrup, K; Rostgaard, J; Holstein-Rathlou, N H


    Cytoplasmic granules have been demonstrated in epithelial cells from the endolymphatic sac, an extraosseus part of the inner ear located in the posterior cranial fossa. Intravenously infused extracts from endolymphatic sacs in anesthetized rats elicited a potent natriuresis and diuresis without...... be the sensory organ/mediator of "cerebral" natriuresis. Furthermore, this substance, tentatively named saccin, may influence the homeostasis of the inner ear fluids and accordingly play a significant role in the pathogenesis of Mèniére's disease....

  17. Integrated annotation and analysis of in situ hybridization images using the ImAnno system: application to the ear and sensory organs of the fetal mouse.

    Romand, Raymond; Ripp, Raymond; Poidevin, Laetitia; Boeglin, Marcel; Geffers, Lars; Dollé, Pascal; Poch, Olivier


    An in situ hybridization (ISH) study was performed on 2000 murine genes representing around 10% of the protein-coding genes present in the mouse genome using data generated by the EURExpress consortium. This study was carried out in 25 tissues of late gestation embryos (E14.5), with a special emphasis on the developing ear and on five distinct developing sensory organs, including the cochlea, the vestibular receptors, the sensory retina, the olfactory organ, and the vibrissae follicles. The results obtained from an analysis of more than 11,000 micrographs have been integrated in a newly developed knowledgebase, called ImAnno. In addition to managing the multilevel micrograph annotations performed by human experts, ImAnno provides public access to various integrated databases and tools. Thus, it facilitates the analysis of complex ISH gene expression patterns, as well as functional annotation and interaction of gene sets. It also provides direct links to human pathways and diseases. Hierarchical clustering of expression patterns in the 25 tissues revealed three main branches corresponding to tissues with common functions and/or embryonic origins. To illustrate the integrative power of ImAnno, we explored the expression, function and disease traits of the sensory epithelia of the five presumptive sensory organs. The study identified 623 genes (out of 2000) concomitantly expressed in the five embryonic epithelia, among which many (∼12%) were involved in human disorders. Finally, various multilevel interaction networks were characterized, highlighting differential functional enrichments of directly or indirectly interacting genes. These analyses exemplify an under-represention of "sensory" functions in the sensory gene set suggests that E14.5 is a pivotal stage between the developmental stage and the functional phase that will be fully reached only after birth.

  18. RAF kinase activity regulates neuroepithelial cell proliferation and neuronal progenitor cell differentiation during early inner ear development.

    Marta Magariños

    Full Text Available BACKGROUND: Early inner ear development requires the strict regulation of cell proliferation, survival, migration and differentiation, coordinated by the concerted action of extrinsic and intrinsic factors. Deregulation of these processes is associated with embryonic malformations and deafness. We have shown that insulin-like growth factor I (IGF-I plays a key role in embryonic and postnatal otic development by triggering the activation of intracellular lipid and protein kinases. RAF kinases are serine/threonine kinases that regulate the highly conserved RAS-RAF-MEK-ERK signaling cascade involved in transducing the signals from extracellular growth factors to the nucleus. However, the regulation of RAF kinase activity by growth factors during development is complex and still not fully understood. METHODOLOGY/PRINCIPAL FINDINGS: By using a combination of qRT-PCR, Western blotting, immunohistochemistry and in situ hybridization, we show that C-RAF and B-RAF are expressed during the early development of the chicken inner ear in specific spatiotemporal patterns. Moreover, later in development B-RAF expression is associated to hair cells in the sensory patches. Experiments in ex vivo cultures of otic vesicle explants demonstrate that the influence of IGF-I on proliferation but not survival depends on RAF kinase activating the MEK-ERK phosphorylation cascade. With the specific RAF inhibitor Sorafenib, we show that blocking RAF activity in organotypic cultures increases apoptosis and diminishes the rate of cell proliferation in the otic epithelia, as well as severely impairing neurogenesis of the acoustic-vestibular ganglion (AVG and neuron maturation. CONCLUSIONS/SIGNIFICANCE: We conclude that RAF kinase activity is essential to establish the balance between cell proliferation and death in neuroepithelial otic precursors, and for otic neuron differentiation and axonal growth at the AVG.

  19. Developing an Ear Prosthesis Fabricated in Polyvinylidene Fluoride by a 3D Printer with Sensory Intrinsic Properties of Pressure and Temperature.

    Suaste-Gómez, Ernesto; Rodríguez-Roldán, Grissel; Reyes-Cruz, Héctor; Terán-Jiménez, Omar


    An ear prosthesis was designed in 3D computer graphics software and fabricated using a 3D printing process of polyvinylidene fluoride (PVDF) for use as a hearing aid. In addition, the prosthesis response to pressure and temperature was observed. Pyroelectric and piezoelectric properties of this ear prosthesis were investigated using an astable multivibrator circuit, as changes in PVDF permittivity were observed according to variations of pressure and temperature. The results show that this prosthesis is reliable for use under different conditions of pressure (0 Pa to 16,350 Pa) and temperature (2 °C to 90 °C). The experimental results show an almost linear and inversely proportional behavior between the stimuli of pressure and temperature with the frequency response. This 3D-printed ear prosthesis is a promising tool and has a great potentiality in the biomedical engineering field because of its ability to generate an electrical potential proportional to pressure and temperature, and it is the first time that such a device has been processed by the additive manufacturing process (3D printing). More work needs to be carried out to improve the performance, such as electrical stimulation of the nervous system, thereby extending the purpose of a prosthesis to the area of sensory perception.

  20. Developing an Ear Prosthesis Fabricated in Polyvinylidene Fluoride by a 3D Printer with Sensory Intrinsic Properties of Pressure and Temperature

    Ernesto Suaste-Gómez


    Full Text Available An ear prosthesis was designed in 3D computer graphics software and fabricated using a 3D printing process of polyvinylidene fluoride (PVDF for use as a hearing aid. In addition, the prosthesis response to pressure and temperature was observed. Pyroelectric and piezoelectric properties of this ear prosthesis were investigated using an astable multivibrator circuit, as changes in PVDF permittivity were observed according to variations of pressure and temperature. The results show that this prosthesis is reliable for use under different conditions of pressure (0 Pa to 16,350 Pa and temperature (2 °C to 90 °C. The experimental results show an almost linear and inversely proportional behavior between the stimuli of pressure and temperature with the frequency response. This 3D-printed ear prosthesis is a promising tool and has a great potentiality in the biomedical engineering field because of its ability to generate an electrical potential proportional to pressure and temperature, and it is the first time that such a device has been processed by the additive manufacturing process (3D printing. More work needs to be carried out to improve the performance, such as electrical stimulation of the nervous system, thereby extending the purpose of a prosthesis to the area of sensory perception.

  1. Brief report: reconstruction of joint hyaline cartilage by autologous progenitor cells derived from ear elastic cartilage.

    Mizuno, Mitsuru; Kobayashi, Shinji; Takebe, Takanori; Kan, Hiroomi; Yabuki, Yuichiro; Matsuzaki, Takahisa; Yoshikawa, Hiroshi Y; Nakabayashi, Seiichiro; Ik, Lee Jeong; Maegawa, Jiro; Taniguchi, Hideki


    In healthy joints, hyaline cartilage covering the joint surfaces of bones provides cushioning due to its unique mechanical properties. However, because of its limited regenerative capacity, age- and sports-related injuries to this tissue may lead to degenerative arthropathies, prompting researchers to investigate a variety of cell sources. We recently succeeded in isolating human cartilage progenitor cells from ear elastic cartilage. Human cartilage progenitor cells have high chondrogenic and proliferative potential to form elastic cartilage with long-term tissue maintenance. However, it is unknown whether ear-derived cartilage progenitor cells can be used to reconstruct hyaline cartilage, which has different mechanical and histological properties from elastic cartilage. In our efforts to develop foundational technologies for joint hyaline cartilage repair and reconstruction, we conducted this study to obtain an answer to this question. We created an experimental canine model of knee joint cartilage damage, transplanted ear-derived autologous cartilage progenitor cells. The reconstructed cartilage was rich in proteoglycans and showed unique histological characteristics similar to joint hyaline cartilage. In addition, mechanical properties of the reconstructed tissues were higher than those of ear cartilage and equal to those of joint hyaline cartilage. This study suggested that joint hyaline cartilage was reconstructed from ear-derived cartilage progenitor cells. It also demonstrated that ear-derived cartilage progenitor cells, which can be harvested by a minimally invasive method, would be useful for reconstructing joint hyaline cartilage in patients with degenerative arthropathies.

  2. Growth Hormone Promotes Hair Cell Regeneration in the Zebrafish (Danio rerio) Inner Ear following Acoustic Trauma

    Huifang Sun; Chia-Hui Lin; Smith, Michael E.


    BACKGROUND: Previous microarray analysis showed that growth hormone (GH) was significantly upregulated following acoustic trauma in the zebrafish (Danio rerio) ear suggesting that GH may play an important role in the process of auditory hair cell regeneration. Our objective was to examine the effects of exogenous and endogenous GH on zebrafish inner ear epithelia following acoustic trauma. METHODOLOGY/PRINCIPAL FINDINGS: We induced auditory hair cell damage by exposing zebrafish to acoustic o...

  3. A rare complication due to button battery cell in ear

    Sharad Hernot


    Full Text Available We report a case of a 7-year-old male child who presented to ENT emergency with 24 h history of excessive pain and blackish otorrhea from right ear after accidentally inserting button battery in the ear while playing. Otoscopic examination revealed a shiny and round foreign body with excessive blackening of the surrounding skin. Chest and abdominal examination and routine investigations were normal. X-ray bilateral mastoid (Schuller's view was done which revealed a radiopaque double-contoured foreign body in the right ear. It was removed under general anesthesia and was confirmed as a button battery. A few days later, biopsy from granulation tissue and surrounding bone was taken which revealed acute suppurative osteomyelitis on histopathological examination.

  4. Blastema from rabbit ear contains progenitor cells comparable to marrow derived mesenchymal stem cells

    Mohamadreza Baghaban Eslaminejad


    Full Text Available Rabbits have the capacity to regenerate holes in their ears by forming a blastema, a tissue that is made up of a group of undifferentiated cells. The purpose of the present study was to isolate and characterize blastema progenitor cells and compare them with marrow mesenchymal stem cells (MSCs. Five New Zealand white male rabbits were used in the present study. A 2-mm hole was created in the animal ears. After 4 days, the blastema ring formed in the periphery of the hole was removed and cultivated. The cells were expanded through several subcultures and compared with the MSCs derived from the marrow of same animal in terms of in vitro differentiation capacity, growth kinetics and culture requirements for optimal proliferation. The primary cultures from both cells tended to be heterogeneous. Fibroblastic cells became progressively dominant with advancing passages. Similar to MSCs blastema passaged-3 cells succeeded to differentiate into bone, cartilage and adipose cell lineages. Even lineage specific genes tended to express in higher level in blastema cells compared to MSCs (p < 0.05. Moreover blastema cells appeared more proliferative; producing more colonies (p < 0.05. While blastema cells showed extensive proliferation in 15% fetal bovine serum (FBS, MSCs displayed higher expansion rate at 10% FBS. In conclusion, blastema from rabbit ear contains a population of fibroblastic cells much similar in characteristic to bone marrow mesenchymal stem cells. However, the two cells were different in the level of lineage-specific gene expression, the growth curve characteristics and the culture requirements.

  5. miR-124 promotes the neuronal differentiation of mouse inner ear neural stem cells

    Jiang, Di; Du, Jintao; Zhang, Xuemei; Zhou, Wei; Zong, Lin; Dong, Chang; Chen, Kaitian; Chen, Yu; Chen, Xihui; Jiang, Hongyan


    MicroRNAs (miRNAs or miRs) act as key regulators in neuronal development, synaptic morphogenesis and plasticity. However, their role in the neuronal differentiation of inner ear neural stem cells (NSCs) remains unclear. In this study, 6 miRNAs were selected and their expression patterns during the neuronal differentiation of inner ear NSCs were examined by RT-qPCR. We demonstrated that the culture of spiral ganglion stem cells present in the inner ears of newborn mice gave rise to neurons in vitro. The expression patterns of miR-124, miR-132, miR-134, miR-20a, miR-17-5p and miR-30a-5p were examined during a 14-day neuronal differentiation period. We found that miR-124 promoted the neuronal differentiation of and neurite outgrowth in mouse inner ear NSCs, and that the changes in the expression of tropomyosin receptor kinase B (TrkB) and cell division control protein 42 homolog (Cdc42) during inner ear NSC differentiation were associated with miR-124 expression. Our findings indicate that miR-124 plays a role in the neuronal differentiation of inner ear NSCs. This finding may lead to the development of novel strategies for restoring hearing in neurodegenerative diseases.

  6. Cell cycle synchronization of canine ear fibroblasts for somatic cell nuclear transfer.

    Koo, Ok Jae; Hossein, Mohammad Shamim; Hong, So Gun; Martinez-Conejero, Jose A; Lee, Byeong Chun


    Cycle synchronization of donor cells in the G0/G1 stage is a crucial step for successful somatic cell nuclear transfer. In the present report, we evaluated the effects of contact inhibition, serum starvation and the reagents - dimethyl sulphoxide (DMSO), roscovitine and cycloheximide (CHX) - on synchronization of canine fibroblasts at the G0/G1 stage. Ear fibroblast cells were collected from a beagle dog, placed into culture and used for analysis at passages three to eight. The population doubling time was 36.5 h. The proportion of G0/G1 cells was significantly increased by contact inhibition (77.1%) as compared with cycling cells (70.1%); however, extending the duration of culture did not induce further synchronization. After 24 h of serum starvation, cells were effectively synchronized at G0/G1 (77.1%). Although synchronization was further increased gradually after 24 h and even showed significant difference after 72 h (82.8%) of starvation, the proportion of dead cells also significantly increased after 24 h. The percentage of cells at the G0/G1 phase was increased (as compared with controls) after 72 h treatment with DMSO (76.1%) and after 48 h treatment with CHX (73.0%) or roscovitine (72.5%). However, the rate of cell death was increased after 24 and 72 h of treatment with DMSO and CHX, respectively. Thus, we recommend the use of roscovitine for cell cycle synchronization of canine ear fibroblasts as a preparatory step for SCNT.

  7. Comparison of Occlusion Effect in Normal Hearing Individuals and those with Slight and Mild Sensory Neural Hearing Loss Via Real Ear Measurement

    Meymaneh Jafari


    Full Text Available Background and Aim: Hearing aid users complain about a phenomenon called "occlusion effect". The aim of this study was to compare the occlusion effect in normal hearing individuals and those with slight and mild sensory neural hearing loss via Real Ear Measurement.Methods: Sixty volunteers (30 male, 30 female aged 18-55 years were enrolled in this study. Subjects were instructed to vocalize /e/ and /i/ for 5 seconds. Sound pressure level was measured by a probe- microphone and recorded in the ear canal. Occlusion effect and the frequency in which maximum occlusion effect occurs were obtained for each individuals for further analysis.Results: The peak of occlusion effect for /e/ was 10.25 dB and 9.77 dB respectively in 751.9 Hz and 542.98 Hz frequencies in female and male individuals. The maximum occlusion effect occurred with 19.03 dB and 19.10 dB for /i/ and in 518.88 Hz and 440.28 Hz in female and male individuals, in respect. In addition, no significant difference was seen among hearing levels and between genders.Conclusion: The peak of occlusion effect varies significantly among hearing aid users so that the hearing aid must be tuned. Probe-microphone measures will assist in determination where frequency- specific adjustments are needed.

  8. Laser microdissection of sensory organ precursor cells of Drosophila microchaetes.

    Eulalie Buffin

    Full Text Available BACKGROUND: In Drosophila, each external sensory organ originates from the division of a unique precursor cell (the sensory organ precursor cell or SOP. Each SOP is specified from a cluster of equivalent cells, called a proneural cluster, all of them competent to become SOP. Although, it is well known how SOP cells are selected from proneural clusters, little is known about the downstream genes that are regulated during SOP fate specification. METHODOLOGY/PRINCIPAL FINDINGS: In order to better understand the mechanism involved in the specification of these precursor cells, we combined laser microdissection, toisolate SOP cells, with transcriptome analysis, to study their RNA profile. Using this procedure, we found that genes that exhibit a 2-fold or greater expression in SOPs versus epithelial cells were mainly associated with Gene Ontology (GO terms related with cell fate determination and sensory organ specification. Furthermore, we found that several genes such as pebbled/hindsight, scabrous, miranda, senseless, or cut, known to be expressed in SOP cells by independent procedures, are particularly detected in laser microdissected SOP cells rather than in epithelial cells. CONCLUSIONS/SIGNIFICANCE: These results confirm the feasibility and the specificity of our laser microdissection based procedure. We anticipate that this analysis will give new insight into the selection and specification of neural precursor cells.

  9. Mechanotransduction in mouse inner ear hair cells requires transmembrane channel-like genes

    Kawashima, Yoshiyuki; Geleoc, Gwenaelle S. G.; Kurima, Kiyoto; Labay, Valentina; Lelli, Andrea; Asai, Yukako; Makishima, Tomoko; Wu, Doris K.; Della Santina, Charles C.; Holt, Jeffrey R.; Griffith, Andrew J.


    Inner ear hair cells convert the mechanical stimuli of sound, gravity, and head movement into electrical signals. This mechanotransduction process is initiated by opening of cation channels near the tips of hair cell stereocilia. Since the identity of these ion channels is unknown, and mutations in

  10. Control of hair cell excitability by vestibular primary sensory neurons.

    Brugeaud, Aurore; Travo, Cécile; Demêmes, Danielle; Lenoir, Marc; Llorens, Jordi; Puel, Jean-Luc; Chabbert, Christian


    International audience; In the rat utricle, synaptic contacts between hair cells and the nerve fibers arising from the vestibular primary neurons form during the first week after birth. During that period, the sodium-based excitability that characterizes neonate utricle sensory cells is switched off. To investigate whether the establishment of synaptic contacts was responsible for the modulation of the hair cell excitability, we used an organotypic culture of rat utricle in which the setting ...

  11. Natural bizbenzoquinoline derivatives protect zebrafish lateral line sensory hair cells from aminoglycoside toxicity

    Matthew eKruger


    Full Text Available Moderate to severe hearing loss affects 360 million people worldwide and most often results from damage to sensory hair cells. Hair cell damage can result from aging, genetic mutations, excess noise exposure, and certain medications including aminoglycoside antibiotics. Aminoglycosides are effective at treating infections associated with cystic fibrosis and other life-threatening conditions such as sepsis, but cause hearing loss in 20-30% of patients. It is therefore imperative to develop new therapies to combat hearing loss and allow safe use of these potent antibiotics. We approach this drug discovery question using the larval zebrafish lateral line because zebrafish hair cells are structurally and functionally similar to mammalian inner ear hair cells and respond similarly to toxins. We screened a library of 502 natural compounds in order to identify novel hair cell protectants. Our screen identified four bisbenzylisoquinoline derivatives: berbamine, E6 berbamine, hernandezine, and isotetrandrine, each of which robustly protected hair cells from aminoglycoside-induced damage. Using fluorescence microscopy and electrophysiology, we demonstrated that the natural compounds confer protection by reducing antibiotic uptake into hair cells and showed that hair cells remain functional during and after incubation in E6 berbamine. We also determined that these natural compounds do not reduce antibiotic efficacy. Together, these natural compounds represent a novel source of possible otoprotective drugs that may offer therapeutic options for patients receiving aminoglycoside treatment.

  12. Squamous cell carcinoma of the middle ear arising from CSOM: A case report

    S R Davanageri


    Full Text Available Squamous cell carcinoma occurring in a background of chronic suppurative otitis media (CSOM is a rare complication. It runs an aggressive course. Hence early identification is significant to prevent disease progression and to improve the survival rate. Subjecting granulation tissue from middle ear for histopathologic examination is of importance to rule out associated malignant change.

  13. Ankrd6 is a mammalian functional homolog of Drosophila planar cell polarity gene diego and regulates coordinated cellular orientation in the mouse inner ear.

    Jones, Chonnettia; Qian, Dong; Kim, Sun Myoung; Li, Shuangding; Ren, Dongdong; Knapp, Lindsey; Sprinzak, David; Avraham, Karen B; Matsuzaki, Fumio; Chi, Fanglu; Chen, Ping


    The coordinated polarization of neighboring cells within the plane of the tissue, known as planar cell polarity (PCP), is a recurring theme in biology. It is required for numerous developmental processes for the form and function of many tissues and organs across species. The genetic pathway regulating PCP was first discovered in Drosophila, and an analogous but distinct pathway is emerging in vertebrates. It consists of membrane protein complexes known as core PCP proteins that are conserved across species. Here we report that the over-expression of the murine Ankrd6 (mAnkrd6) gene that shares homology with Drosophila core PCP gene diego causes a typical PCP phenotype in Drosophila, and mAnkrd6 can rescue the loss of function of diego in Drosophila. In mice, mAnkrd6 protein is asymmetrically localized in cells of the inner ear sensory organs, characteristic of components of conserved core PCP complexes. The loss of mAnkrd6 causes PCP defects in the inner ear sensory organs. Moreover, canonical Wnt signaling is significantly increased in mouse embryonic fibroblasts from mAnkrd6 knockout mice in comparison to wild type controls. Together, these results indicated that mAnkrd6 is a functional homolog of the Drosophila diego gene for mammalian PCP regulation and act to suppress canonical Wnt signaling.

  14. Fates of mouse embryonic stem cells transplanted into the inner ears of adult mice and embryonic chickens.

    Sakamoto, Tatsunori; Nakagawa, Takayuki; Endo, Tsuyoshi; Kim, Tae-Soo; Iguchi, Fukuichiro; Naito, Yasushi; Sasai, Yoshiki; Ito, Juichi


    The potential of embryonic stem (ES) cells to differentiate into inner ear hair cells was examined in this study. Undifferentiated mouse ES cells transplanted into neomycin-damaged mouse inner ears were evaluated by immunohistochemistry 4 weeks after transplantation. Some ES cells were positive for E-cadherin or NCAM, and most transplanted cells were positive for SSEA3 and Ki67. None were positive for Myosin VIIa or MF20. These results indicate that the damaged inner ear may have some activity inducing ES cells to develop into ectoderm cells, but the effect was insufficient to induce inner ear hair cells. Next, SDIA/BMP-treated ES cells were transplanted into embryonic chicken inner ear rudiments. Embryonic chickens were expected to share the same developmental systems as mice. SDIA/BMP treatment drove ES cells to the population including neural crest cells and probably placode cells ES colonies were found next to or in the otic vesicles but were not a part of vesicle walls, indicating that transplanted ES cells could not be expected to be the same kind of cells as chicken otic vesicle cells Some ES colonies were found at the vestibulo-cochlear ganglions. To induce inner ear hair cells in this system, the competency of ES cells and otic induction signals should be defined further.

  15. Ear Tubes

    ... ENTCareers Marketplace Find an ENT Doctor Near You Ear Tubes Ear Tubes Patient Health Information News media ... and throat specialist) may be considered. What are ear tubes? Ear tubes are tiny cylinders placed through ...

  16. [Investigation of neural stem cell-derived donor contribution in the inner ear following blastocyst injection].

    Volkenstein, S; Brors, D; Hansen, S; Mlynski, R; Dinger, T C; Müller, A M; Dazert, S


    Utilising the enormous proliferation and multi-lineage differentiation potentials of somatic stem cells represents a possible therapeutical strategy for diseases of non-regenerative tissues like the inner ear. In the current study, the possibility of murine neural stem cells to contribute to the developing inner ear following blastocyst injection was investigated. Fetal brain-derived neural stem cells from the embryonic day 14 cortex of male mice were isolated and expanded for four weeks in neurobasal media supplemented with bFGF and EGF. Neural stem cells of male animals were harvested, injected into blastocysts and the blastocysts were transferred into pseudo-pregnant foster animals. Each blastocyst was injected with 5-15 microspheres growing from single cell suspension from neurospheres dissociated the day before. The resulting mice were investigated six months POST PARTUM for the presence of donor cells. Brainstem evoked response audiometry (BERA) was performed in six animals. To visualize donor cells Lac-Z staining was performed on sliced cochleas of two animals. In addition, the cochleas of four female animals were isolated and genomic DNA of the entire cochlea was analyzed for donor contribution by Y-chromosome-specific PCR. All animals had normal thresholds in brainstem evoked response audiometry. The male-specific PCR product indicating the presence of male donor cells were detected in the cochleas of three of the four female animals investigated. In two animals, male donor cells were detected unilateral, in one animal bilateral. The results suggest that descendants of neural stem cells are detectable in the inner ear after injection into blastocysts and possess the ability to integrate into the developing inner ear without obvious loss in hearing function.

  17. SuperSILAC Quantitative Proteome Profiling of Murine Middle Ear Epithelial Cell Remodeling with NTHi.

    Stéphanie Val

    Full Text Available Chronic Otitis Media with effusion (COME develops after sustained inflammation and is characterized by secretory middle ear epithelial metaplasia and effusion, most frequently mucoid. Non-typeable Haemophilus influenzae (NTHi, the most common acute Otitis Media (OM pathogen, is postulated to promote middle ear epithelial remodeling in the progression of OM from acute to chronic. The goals of this study were to examine histopathological and quantitative proteomic epithelial effects of NTHi challenge in a murine middle ear epithelial cell line.NTHi lysates were generated and used to stimulate murine epithelial cells (mMEEC cultured at air-liquid interface over 48 hours- 1 week. Conditional quantitative Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC of cell lysates was performed to interrogate the global protein production in the cells, using the SuperSILAC technique. Histology of the epithelium over time was done to measure bacterial dependent remodeling.Mass spectrometry analysis identified 2,565 proteins across samples, of which 74 exhibited differential enrichment or depletion in cell lysates (+/-2.0 fold-change; p value<0.05. The key molecular functions regulated by NTHi lysates exposure were related to cell proliferation, death, migration, adhesion and inflammation. Finally, chronic exposure induced significant epithelial thickening of cells grown at air liquid interface.NTHi lysates drive pathways responsible of cell remodeling in murine middle ear epithelium which likely contributes to observed epithelial hyperplasia in vitro. Further elucidation of these mediators will be critical in understanding the progression of OM from acute to chronic at the molecular level.

  18. Causes and Consequences of Sensory Hair Cell Damage and Recovery in Fishes.

    Smith, Michael E; Monroe, J David


    Sensory hair cells are the mechanotransductive receptors that detect gravity, sound, and vibration in all vertebrates. Damage to these sensitive receptors often results in deficits in vestibular function and hearing. There are currently two main reasons for studying the process of hair cell loss in fishes. First, fishes, like other non-mammalian vertebrates, have the ability to regenerate hair cells that have been damaged or lost via exposure to ototoxic chemicals or acoustic overstimulation. Thus, they are used as a biomedical model to understand the process of hair cell death and regeneration and find therapeutics that treat or prevent human hearing loss. Secondly, scientists and governmental natural resource managers are concerned about the potential effects of intense anthropogenic sounds on aquatic organisms, including fishes. Dr. Arthur N. Popper and his students, postdocs and research associates have performed pioneering experiments in both of these lines of fish hearing research. This review will discuss the current knowledge regarding the causes and consequences of both lateral line and inner ear hair cell damage in teleost fishes.

  19. CBA小鼠内耳感觉上皮的参考数据%Reference data of sensory epithelium in the inner ear in CBA mice

    刘洪; 丁大连; 孙虹; 蒋海燕; RichardSalvi


    Objective To provide useful reference data of sensory epithelium in the inner ear, the cochlear and vestibular system were carefully measured in CBA mice. Methods Six young CBA mice at three months of age were used for this study. The surface preparations of cochlear basilar membrane and vestibular end-organs were measured under light microscope. The length and the width of basilar membrane and organ of Corti were examined along the cochlear basilar membrane. In addition, the total number and the density of cochlear hair cell along the basilar membrane were also calculated. To evaluate the vestibular end-organs, the total amount of hair cells in macula of saccule and utricle were counted. The hair cell density of striola region and marginal region in saccule and utricle were calculated respectively, and the density of hair cells in cristae in membranous ampulla of three semicircular canals were also counted. Results The total length of the cochlear basilar membrane was 5.76 ±0.196 mm in CBA mice. The width of basilar membrane was 339.1 ±9.87 μm at 1.5 mm, 304.5 ± 11.82 μm at 3 mm, and 300.1 ±7.22μm at 5 mm from the cochlear base respectively. This indicated that the width of cochlear basilar membrane was gradually narrowing from base to apex. In contrast, the width of organ of Corti was 37.80±2.24 μm at 1.5 mm, 45.00±2.67μm at 3 mm, and 52.20 ± 3.16 fun at 5 mm from the base respectively, which demonstrated that the width of organ of Corti was gradually increasing from base to apex. The total number of cochlear hair cells in CBA mice was 3116.41 ± 151.91, which included 680.67 ± 17.50 inner hair cells and 2435.8 ± 143.46 outer hair cells. The density of cochlear hair cells was similar across the entire length of the cochlea with a density of 541.1 ± 9.36/mm. The density of inner hair cells and outer hair cells were 118.3±2.68/mm and 422.8 ± 11.87/mm respectively. The total number of hair cells in macula of utricle and saccule were 3300 ± 177

  20. Satellite glial cells in sensory ganglia: its role in pain

    Filipa Alexandra Leite Costa


    Full Text Available BACKGROUND AND OBJECTIVES: Satellite glial cells in sensory ganglia are a recent subject of research in the field of pain and a possible therapeutic target in the future. Therefore, the aim of this study was to summarize some of the important physiological and morphological characteristics of these cells and gather the most relevant scientific evidence about its possible role in the development of chronic pain. CONTENT: In the sensory ganglia, each neuronal body is surrounded by satellite glial cells forming distinct functional units. This close relationship enables bidirectional communication via a paracrine signaling between those two cell types. There is a growing body of evidence that glial satellite cells undergo structural and biochemical changes after nerve injury, which influence neuronal excitability and consequently the development and/or maintenance of pain in different animal models of chronic pain. CONCLUSIONS: Satellite glial cells are important in the establishment of physiological pain, in addition to being a potential target for the development of new pain treatments.

  1. TMC1 and TMC2 Localize at the Site of Mechanotransduction in Mammalian Inner Ear Hair Cell Stereocilia

    Kiyoto Kurima


    Full Text Available Mechanosensitive ion channels at stereocilia tips mediate mechanoelectrical transduction (MET in inner ear sensory hair cells. Transmembrane channel-like 1 and 2 (TMC1 and TMC2 are essential for MET and are hypothesized to be components of the MET complex, but evidence for their predicted spatiotemporal localization in stereocilia is lacking. Here, we determine the stereocilia localization of the TMC proteins in mice expressing TMC1-mCherry and TMC2-AcGFP. Functionality of the tagged proteins was verified by transgenic rescue of MET currents and hearing in Tmc1Δ/Δ;Tmc2Δ/Δ mice. TMC1-mCherry and TMC2-AcGFP localize along the length of immature stereocilia. However, as hair cells develop, the two proteins localize predominantly to stereocilia tips. Both TMCs are absent from the tips of the tallest stereocilia, where MET activity is not detectable. This distribution was confirmed for the endogenous proteins by immunofluorescence. These data are consistent with TMC1 and TMC2 being components of the stereocilia MET channel complex.

  2. Planar cell polarity and a potential role for a Wnt morphogen gradient in stereociliary bundle orientation in the mammalian inner ear.

    Dabdoub, Alain; Kelley, Matthew W


    The planar cell polarity (PCP) pathway, a noncanonical Wnt signaling pathway, is crucial for embryonic development in all animals as it is responsible for the regulation of coordinated orientation of structures within the plane of the various epithelia. In the mammalian cochlea, one of the best examples of planar polarity in vertebrates, stereociliary bundles located on mechanosensory hair cells within the sensory epithelium are all uniformly polarized. Generation of this polarity is important for hair cell mechanotransduction and auditory perception as stereociliary bundles are only sensitive to vibrations in their single plane of polarization. We describe the two step developmental process that results in the generation of planar polarity in the mammalian inner ear. Furthermore, we review evidence for the role of Wnt signaling, and the possible generation of a Wnt gradient, in planar polarity.

  3. Evolution and development of the vertebrate ear

    Fritzsch, B.; Beisel, K. W.


    This review outlines major aspects of development and evolution of the ear, specifically addressing issues of cell fate commitment and the emerging molecular governance of these decisions. Available data support the notion of homology of subsets of mechanosensors across phyla (proprioreceptive mechanosensory neurons in insects, hair cells in vertebrates). It is argued that this conservation is primarily related to the specific transducing environment needed to achieve mechanosensation. Achieving this requires highly conserved transcription factors that regulate the expression of the relevant structural genes for mechanosensory transduction. While conserved at the level of some cell fate assignment genes (atonal and its mammalian homologue), the ear has also radically reorganized its development by implementing genes used for cell fate assignment in other parts of the developing nervous systems (e.g., neurogenin 1) and by evolving novel sets of genes specifically associated with the novel formation of sensory neurons that contact hair cells (neurotrophins and their receptors). Numerous genes have been identified that regulate morphogenesis, but there is only one common feature that emerges at the moment: the ear appears to have co-opted genes from a large variety of other parts of the developing body (forebrain, limbs, kidneys) and establishes, in combination with existing transcription factors, an environment in which those genes govern novel, ear-related morphogenetic aspects. The ear thus represents a unique mix of highly conserved developmental elements combined with co-opted and newly evolved developmental elements.

  4. Cauliflower Ear

    ... dientes Video: Getting an X-ray What's Cauliflower Ear? KidsHealth > For Kids > What's Cauliflower Ear? Print A A A Have you ever seen someone whose ear looks bumpy and lumpy? The person might have ...

  5. Ear barotrauma

    Barotitis media; Barotrauma; Ear popping - barotrauma; Pressure-related ear pain; Eustachian tube dysfunction - barotrauma ... The air pressure in the middle ear is most often the same as the air ... body. The Eustachian tube is a connection between the middle ...

  6. Swimmer's ear

    ... worse when you pull on the outer ear Hearing loss Itching of the ear or ear canal ... reduce itching and inflammation Pain medicine, such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) Vinegar (acetic acid) ...

  7. Winer’s Nodular Calcinosis Mimicking Squamous Cell Carcinoma On The Ear

    Emine Çiğdem Karadağ


    Full Text Available Winer’s nodular calcinosis, presenting as an asymptomatic, firm, white, or yellow nodule at birth or during early childhood, is a form of idiopathic calcinosis cutis. Ulceration on Winer’s nodular calcinosis is rarely seen. Till date, there is no report in the literature regarding the malignant skin lesion confused with Winer’s nodular calcinosis. No similar case or article has been encountered in the Turkish or English literature regarding the malignant skin lesion that might be confused with Winer’s nodular calcinosis. The case of a 3-year-old girl with a 3×2 mm, white, ulcerated, nodular lesion on the helix of the left ear is presented here. The lesion was thought to be a squamous cell carcinoma due to the ulceration and appearance, and it was located on the ear, which is frequently exposed to the sun.

  8. Ear wax

    Browning, George GG


    Ear wax only becomes a problem if it causes a hearing impairment, or other ear-related symptoms. Ear wax is more likely to accumulate and cause a hearing impairment when normal extrusion is prevented — for example, by hearing aids, or by the use of cotton buds to clean the ears.Ear wax can visually obscure the ear drum, and may need to be removed for diagnostic purposes.

  9. Signaling from maize organ primordia via FASCIATED EAR3 regulates stem cell proliferation and yield traits.

    Je, Byoung Il; Gruel, Jeremy; Lee, Young Koung; Bommert, Peter; Arevalo, Edgar Demesa; Eveland, Andrea L; Wu, Qingyu; Goldshmidt, Alexander; Meeley, Robert; Bartlett, Madelaine; Komatsu, Mai; Sakai, Hajime; Jönsson, Henrik; Jackson, David


    Shoot apical meristems are stem cell niches that balance proliferation with the incorporation of daughter cells into organ primordia. This balance is maintained by CLAVATA-WUSCHEL feedback signaling between the stem cells at the tip of the meristem and the underlying organizing center. Signals that provide feedback from organ primordia to control the stem cell niche in plants have also been hypothesized, but their identities are unknown. Here we report FASCIATED EAR3 (FEA3), a leucine-rich-repeat receptor that functions in stem cell control and responds to a CLAVATA3/ESR-related (CLE) peptide expressed in organ primordia. We modeled our results to propose a regulatory system that transmits signals from differentiating cells in organ primordia back to the stem cell niche and that appears to function broadly in the plant kingdom. Furthermore, we demonstrate an application of this new signaling feedback, by showing that weak alleles of fea3 enhance hybrid maize yield traits.

  10. Characterization and development of an inner ear type I fibrocyte cell culture.

    Gratton, M A; Schulte, B A; Hazen-Martin, D J


    A method has been developed that allows successful maintenance of secondary cell cultures derived from explants of the cochlear lateral wall of young adult gerbils. The secondary cultures were characterized morphologically with light and transmission electron microscopy and immunocytochemically with protein markers specific to various lateral wall cell types. Structural studies revealed fusiform-shaped cells with a paucity of cytoplasm surrounding the nucleus and slender processes. The cells showed little evidence of intercellular contact even when confluent. The cultures were immunopositive for vimentin, carbonic anhydrase isozyme II, creatine kinase isozyme BB and smooth endoplasmic reticulum Ca-ATPase, but lacked reactivity for cytokeratins and Na,K-ATPase. The results indicate that the cultures are comprised of type I fibrocytes from the spiral ligament. These findings are the first to demonstrate that inner ear spiral ligament cells can be isolated and maintained in secondary culture while retaining many of their in vivo characteristics. Based upon their location and content of ion transport enzymes, type I fibrocytes are thought to be involved in the recycling of potassium from perilymph into the stria vascularis. The establishment of this cell line provides a means to analyze the role of spiral ligament fibrocytes in maintenance of inner ear homeostasis.

  11. Aquaporin-4 in Astroglial Cells in the CNS and Supporting Cells of Sensory Organs—A Comparative Perspective

    Corinna Gleiser


    Full Text Available The main water channel of the brain, aquaporin-4 (AQP4, is one of the classical water-specific aquaporins. It is expressed in many epithelial tissues in the basolateral membrane domain. It is present in the membranes of supporting cells in most sensory organs in a specifically adapted pattern: in the supporting cells of the olfactory mucosa, AQP4 occurs along the basolateral aspects, in mammalian retinal Müller cells it is highly polarized. In the cochlear epithelium of the inner ear, it is expressed basolaterally in some cells but strictly basally in others. Within the central nervous system, aquaporin-4 (AQP4 is expressed by cells of the astroglial family, more specifically, by astrocytes and ependymal cells. In the mammalian brain, AQP4 is located in high density in the membranes of astrocytic endfeet facing the pial surface and surrounding blood vessels. At these locations, AQP4 plays a role in the maintenance of ionic homeostasis and volume regulation. This highly polarized expression has not been observed in the brain of fish where astroglial cells have long processes and occur mostly as radial glial cells. In the brain of the zebrafish, AQP4 immunoreactivity is found along the radial extent of astroglial cells. This suggests that the polarized expression of AQP4 was not present at all stages of evolution. Thus, a polarized expression of AQP4 as part of a control mechanism for a stable ionic environment and water balanced occurred at several locations in supporting and glial cells during evolution. This initially basolateral membrane localization of AQP4 is shifted to highly polarized expression in astrocytic endfeet in the mammalian brain and serves as a part of the neurovascular unit to efficiently maintain homeostasis.

  12. Aquaporin-4 in Astroglial Cells in the CNS and Supporting Cells of Sensory Organs-A Comparative Perspective.

    Gleiser, Corinna; Wagner, Andreas; Fallier-Becker, Petra; Wolburg, Hartwig; Hirt, Bernhard; Mack, Andreas F


    The main water channel of the brain, aquaporin-4 (AQP4), is one of the classical water-specific aquaporins. It is expressed in many epithelial tissues in the basolateral membrane domain. It is present in the membranes of supporting cells in most sensory organs in a specifically adapted pattern: in the supporting cells of the olfactory mucosa, AQP4 occurs along the basolateral aspects, in mammalian retinal Müller cells it is highly polarized. In the cochlear epithelium of the inner ear, it is expressed basolaterally in some cells but strictly basally in others. Within the central nervous system, aquaporin-4 (AQP4) is expressed by cells of the astroglial family, more specifically, by astrocytes and ependymal cells. In the mammalian brain, AQP4 is located in high density in the membranes of astrocytic endfeet facing the pial surface and surrounding blood vessels. At these locations, AQP4 plays a role in the maintenance of ionic homeostasis and volume regulation. This highly polarized expression has not been observed in the brain of fish where astroglial cells have long processes and occur mostly as radial glial cells. In the brain of the zebrafish, AQP4 immunoreactivity is found along the radial extent of astroglial cells. This suggests that the polarized expression of AQP4 was not present at all stages of evolution. Thus, a polarized expression of AQP4 as part of a control mechanism for a stable ionic environment and water balanced occurred at several locations in supporting and glial cells during evolution. This initially basolateral membrane localization of AQP4 is shifted to highly polarized expression in astrocytic endfeet in the mammalian brain and serves as a part of the neurovascular unit to efficiently maintain homeostasis.

  13. Developmental evolutionary biology of the vertebrate ear: conserving mechanoelectric transduction and developmental pathways in diverging morphologies

    Fritzsch, B.; Beisel, K. W.; Bermingham, N. A.


    This brief overview shows that a start has been made to molecularly dissect vertebrate ear development and its evolutionary conservation to the development of the insect hearing organ. However, neither the patterning process of the ear nor the patterning process of insect sensory organs is sufficiently known at the moment to provide more than a first glimpse. Moreover, hardly anything is known about otocyst development of the cephalopod molluscs, another triploblast lineage that evolved complex 'ears'. We hope that the apparent conserved functional and cellular components present in the ciliated sensory neurons/hair cells will also be found in the genes required for vertebrate ear and insect sensory organ morphogenesis (Fig. 3). Likewise, we expect that homologous pre-patterning genes will soon be identified for the non-sensory cell development, which is more than a blocking of neuronal development through the Delta/Notch signaling system. Generation of the apparently unique ear could thus represent a multiplication of non-sensory cells by asymmetric and symmetric divisions as well as modification of existing patterning process by implementing novel developmental modules. In the final analysis, the vertebrate ear may come about by increasing the level of gene interactions in an already existing and highly conserved interactive cascade of bHLH genes. Since this was apparently achieved in all three lineages of triploblasts independently (Fig. 3), we now need to understand how much of the morphogenetic cascades are equally conserved across phyla to generate complex ears. The existing mutations in humans and mice may be able to point the direction of future research to understand the development of specific cell types and morphologies in the formation of complex arthropod, cephalopod, and vertebrate 'ears'.

  14. Hair cell specific NTPDase6 immunolocalisation in vestibular end organs: potential role of purinergic signaling in vestibular sensory transduction.

    O'Keeffe, Mary G; Thorne, Peter R; Housley, Gary D; Robson, Simon C; Vlajkovic, Srdjan M


    A complex extracellular nucleotide signalling system acting on P2 receptors is involved in regulation of cochlear function in the mammalian inner ear. Ectonucleoside triphosphate diphosphohydrolases (E-NTPDases) are ectonucleotidases that regulate P2 receptor signalling pathways in mammalian tissues by hydrolysing extracellular nucleotides to the respective nucleosides. All enzymes from the CD39/ENTPD family (NTPDase1-8) are expressed in the adult rat cochlea, but their expression and distribution in the vestibular end organ is unknown. This report demonstrates selective expression of NTPDase6 by rat vestibular hair cells. Hair cells transducing both angular acceleration (crista ampullaris) and static head position (maculae of the utricle and saccule) exhibited strong immunolabelling with a bias towards the sensory pole and in particular, the hair cell bundle. NTPDase6 is an intracellular enzyme that can be released in a soluble form from cell cultures and shows an enzymatic preference for nucleoside 5'-diphosphates, such as guanosine 5'-diphosphate (GDP) and uridine 5'-diphosphate (UDP). The main function of NTPDase6 may be the regulation of nucleotide levels in cellular organelles by regulating the conversion of nucleotides to nucleosides. NTPDase6 immunolocalisation in the vestibular end organ could be linked to the regulation of P2 receptor signalling and sensory transduction, including maintenance of vestibular hair bundles.

  15. Your Ears

    ... gross and useful. continue The Middle Ear: Good Vibrations After sound waves enter the outer ear, they travel through the ... ear's main job is to take those sound waves and turn them into vibrations that are delivered to the inner ear. To ...

  16. Ear Pieces

    DiJulio, Betsy


    In this article, the author describes an art project wherein students make fanciful connections between art and medicine. This project challenges students to interpret "ear idioms" (e.g. "blow it out your ear," "in one ear and out the other") by relying almost entirely on realistic ear drawings, the placement of them, marks, and values. In that…

  17. Expression of polysialylated neural cell adhesion molecules on adult stem cells after neuronal differentiation of inner ear spiral ganglion neurons.

    Park, Kyoung Ho; Yeo, Sang Won; Troy, Frederic A


    During brain development, polysialylated (polySia) neural cell adhesion molecules (polySia-NCAMs) modulate cell-cell adhesive interactions involved in synaptogenesis, neural plasticity, myelination, and neural stem cell (NSC) proliferation and differentiation. Our findings show that polySia-NCAM is expressed on NSC isolated from adult guinea pig spiral ganglion (GPSG), and in neurons and Schwann cells after differentiation of the NSC with epidermal, glia, fibroblast growth factors (GFs) and neurotrophins. These differentiated cells were immunoreactive with mAb's to polySia, NCAM, β-III tubulin, nestin, S-100 and stained with BrdU. NSC could regenerate and be differentiated into neurons and Schwann cells. We conclude: (1) polySia is expressed on NSC isolated from adult GPSG and on neurons and Schwann cells differentiated from these NSC; (2) polySia is expressed on neurons primarily during the early stage of neuronal development and is expressed on Schwann cells at points of cell-cell contact; (3) polySia is a functional biomarker that modulates neuronal differentiation in inner ear stem cells. These new findings suggest that replacement of defective cells in the inner ear of hearing impaired patients using adult spiral ganglion neurons may offer potential hope to improve the quality of life for patients with auditory dysfunction and impaired hearing disorders. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  18. Expression of polysialylated neural cell adhesion molecules on adult stem cells after neuronal differentiation of inner ear spiral ganglion neurons

    Park, Kyoung Ho [Department of Otolaryngology Head and Neck Surgery, College of Medicine, Catholic University, Seoul (Korea, Republic of); Yeo, Sang Won, E-mail: [Department of Otolaryngology Head and Neck Surgery, College of Medicine, Catholic University, Seoul (Korea, Republic of); Troy, Frederic A., E-mail: [Department of Biochemistry and Molecular Medicine, University of California, School of Medicine, Davis, CA 95616 (United States); Xiamen University, School of Medicine, Xiamen City (China)


    Highlights: • PolySia expressed on neurons primarily during early stages of neuronal development. • PolySia–NCAM is expressed on neural stem cells from adult guinea pig spiral ganglion. • PolySia is a biomarker that modulates neuronal differentiation in inner ear stem cells. - Abstract: During brain development, polysialylated (polySia) neural cell adhesion molecules (polySia–NCAMs) modulate cell–cell adhesive interactions involved in synaptogenesis, neural plasticity, myelination, and neural stem cell (NSC) proliferation and differentiation. Our findings show that polySia–NCAM is expressed on NSC isolated from adult guinea pig spiral ganglion (GPSG), and in neurons and Schwann cells after differentiation of the NSC with epidermal, glia, fibroblast growth factors (GFs) and neurotrophins. These differentiated cells were immunoreactive with mAb’s to polySia, NCAM, β-III tubulin, nestin, S-100 and stained with BrdU. NSC could regenerate and be differentiated into neurons and Schwann cells. We conclude: (1) polySia is expressed on NSC isolated from adult GPSG and on neurons and Schwann cells differentiated from these NSC; (2) polySia is expressed on neurons primarily during the early stage of neuronal development and is expressed on Schwann cells at points of cell–cell contact; (3) polySia is a functional biomarker that modulates neuronal differentiation in inner ear stem cells. These new findings suggest that replacement of defective cells in the inner ear of hearing impaired patients using adult spiral ganglion neurons may offer potential hope to improve the quality of life for patients with auditory dysfunction and impaired hearing disorders.

  19. Ear trauma.

    Eagles, Kylee; Fralich, Laura; Stevenson, J Herbert


    Understanding basic ear anatomy and function allows an examiner to quickly and accurately identify at-risk structures in patients with head and ear trauma. External ear trauma (ie, hematoma or laceration) should be promptly treated with appropriate injury-specific techniques. Tympanic membrane injuries have multiple mechanisms and can often be conservatively treated. Temporal bone fractures are a common cause of ear trauma and can be life threatening. Facial nerve injuries and hearing loss can occur in ear trauma.

  20. Developing an Ear Prosthesis Fabricated in Polyvinylidene Fluoride by a 3D Printer with Sensory Intrinsic Properties of Pressure and Temperature

    Ernesto Suaste-Gómez; Grissel Rodríguez-Roldán; Héctor Reyes-Cruz; Omar Terán-Jiménez


    An ear prosthesis was designed in 3D computer graphics software and fabricated using a 3D printing process of polyvinylidene fluoride (PVDF) for use as a hearing aid. In addition, the prosthesis response to pressure and temperature was observed. Pyroelectric and piezoelectric properties of this ear prosthesis were investigated using an astable multivibrator circuit, as changes in PVDF permittivity were observed according to variations of pressure and temperature. The results show that this pr...

  1. Transplantation and survival of mouse inner ear progenitor/stem cells in the organ of Corti after cochleostomy of hearing-impaired guinea pigs: preliminary results

    L.C.M. Barboza Jr.


    Full Text Available In mammals, damage to sensory receptor cells (hair cells of the inner ear results in permanent sensorineural hearing loss. Here, we investigated whether postnatal mouse inner ear progenitor/stem cells (mIESCs are viable after transplantation into the basal turns of neomycin-injured guinea pig cochleas. We also examined the effects of mIESC transplantation on auditory functions. Eight adult female Cavia porcellus guinea pigs (250-350g were deafened by intratympanic neomycin delivery. After 7 days, the animals were randomly divided in two groups. The study group (n=4 received transplantation of LacZ-positive mIESCs in culture medium into the scala tympani. The control group (n=4 received culture medium only. At 2 weeks after transplantation, functional analyses were performed by auditory brainstem response measurement, and the animals were sacrificed. The presence of mIESCs was evaluated by immunohistochemistry of sections of the cochlea from the study group. Non-parametric tests were used for statistical analysis of the data. Intratympanic neomycin delivery damaged hair cells and increased auditory thresholds prior to cell transplantation. There were no significant differences between auditory brainstem thresholds before and after transplantation in individual guinea pigs. Some mIESCs were observed in all scalae of the basal turns of the injured cochleas, and a proportion of these cells expressed the hair cell marker myosin VIIa. Some transplanted mIESCs engrafted in the cochlear basilar membrane. Our study demonstrates that transplanted cells survived and engrafted in the organ of Corti after cochleostomy.

  2. Cell-cell junctions: a target of acoustic overstimulation in the sensory epithelium of the cochlea

    Zheng Guiliang


    Full Text Available Abstract Background Exposure to intense noise causes the excessive movement of the organ of Corti, stretching the organ and compromising sensory cell functions. We recently revealed changes in the transcriptional expression of multiple adhesion-related genes during the acute phases of cochlear damage, suggesting that the disruption of cell-cell junctions is an early event in the process of cochlear pathogenesis. However, the functional state of cell junctions in the sensory epithelium is not clear. Here, we employed graded dextran-FITC, a macromolecule tracer that is impermeable to the organ of Corti under physiological conditions, to evaluate the barrier function of cell junctions in normal and noise-traumatized cochlear sensory epithelia. Results Exposure to an impulse noise of 155 dB (peak sound pressure level caused a site-specific disruption in the intercellular junctions within the sensory epithelium of the chinchilla cochlea. The most vulnerable sites were the junctions among the Hensen cells and between the Hensen and Deiters cells within the outer zone of the sensory epithelium. The junction clefts that formed in the reticular lamina were permeable to 40 and 500 but not 2,000 kDa dextran-FITC macromolecules. Moreover, this study showed that the interruption of junction integrity occurred in the reticular lamina and also in the basilar membrane, a site that had been considered to be resistant to acoustic injury. Finally, our study revealed a general spatial correlation between the site of sensory cell damage and the site of junction disruption. However, the two events lacked a strict one-to-one correlation, suggesting that the disruption of cell-cell junctions is a contributing, but not the sole, factor for initiating acute sensory cell death. Conclusions Impulse noise causes the functional disruption of intercellular junctions in the sensory epithelium of the chinchilla cochlea. This disruption occurs at an early phase of cochlear

  3. Probing the Xenopus laevis inner ear transcriptome for biological function

    Powers TuShun R


    Full Text Available Abstract Background The senses of hearing and balance depend upon mechanoreception, a process that originates in the inner ear and shares features across species. Amphibians have been widely used for physiological studies of mechanotransduction by sensory hair cells. In contrast, much less is known of the genetic basis of auditory and vestibular function in this class of animals. Among amphibians, the genus Xenopus is a well-characterized genetic and developmental model that offers unique opportunities for inner ear research because of the amphibian capacity for tissue and organ regeneration. For these reasons, we implemented a functional genomics approach as a means to undertake a large-scale analysis of the Xenopus laevis inner ear transcriptome through microarray analysis. Results Microarray analysis uncovered genes within the X. laevis inner ear transcriptome associated with inner ear function and impairment in other organisms, thereby supporting the inclusion of Xenopus in cross-species genetic studies of the inner ear. The use of gene categories (inner ear tissue; deafness; ion channels; ion transporters; transcription factors facilitated the assignment of functional significance to probe set identifiers. We enhanced the biological relevance of our microarray data by using a variety of curation approaches to increase the annotation of the Affymetrix GeneChip® Xenopus laevis Genome array. In addition, annotation analysis revealed the prevalence of inner ear transcripts represented by probe set identifiers that lack functional characterization. Conclusions We identified an abundance of targets for genetic analysis of auditory and vestibular function. The orthologues to human genes with known inner ear function and the highly expressed transcripts that lack annotation are particularly interesting candidates for future analyses. We used informatics approaches to impart biologically relevant information to the Xenopus inner ear transcriptome

  4. Development of the ear and of connections between the ear and the brain: is there a role for gravity?

    Fritzsch, B.; Maklad, A.; Bruce, L. L.; Crapon de Caprona, M.-D.


    This paper outlines the development of the gravistatic sensory system of the ear. First, evidence is presented that a genetic program, for which major transcription factors have already been identified using gene expression studies and targeted mutagenesis, governs the initial development of this system. Second, the formation of sensory neurons and their connections to the brain is described as revealed by tracing studies and genetic manipulations. It is concluded that the initial development of the connections of sensory neurons with mechanosensory transducers of the ear (the hair cells) and the targets in the brainstem (vestibular nuclei) is also dependent on fairly rigid genetic programs. During late embryonic and early postnatal development, however, sensory input appears to be used to fine-tune connections of these sensory neurons with the hair cells in the ear as well as with second order vestibular neurons in the brainstem. This phase is proposed to be critical for a proper calibration of the gravistatic information processing in the brain.

  5. Sensory Transduction of the CO2 Response of Guard Cells

    Dr. Eduardo Zeiger


    Stomata have a key role in the regulation of gas exchange and intercellular CO2 concentrations of leaves. Guard cells sense internal and external signals in the leaf environment and transduce these signals into osmoregulatory processes that control stomatal apertures. This research proposal addresses the characterization of the sensory transduction of the CO2 signal in guard cells. Recent studies have shown that in Vicia leaves kept at constant light and temperature in a growth chamber, changes in ambient CO2 concentrations cause large changes in guard cell zeaxanthin that are linear with CO2-dependent changes in stomatal apertures. Research proposed here will test the hypothesis that zeaxanthin function as a transducer of CO2 signals in guard cells. Three central aspects of this hypothesis will be investigated: CO2 sensing by the carboxylation reaction of Rubisco in the guard cell chloroplast, which would modulate zeaxanthin concentrations via changes in lumen pH; transduction of the CO2 signal by zeaxanthin via a transducing cascade that controls guard cell osmoregulation; and blue light dependence of the CO2 signal transduction by zeaxanthin, required for the formation of an isomeric form of zeaxanthin that is physiologically active as a transducer. The role of Rubisco in CO2 sensing will be investigated in experiments characterizing the stomatal response to CO2 in the Arabidopsis mutants R100 and rca-, which have reduced rates of Rubisco-dependent carboxylation. The role of zeaxanthin as a CO2 transducer will be studied in npq1, a zeaxanthin-less mutant. The blue light-dependence of CO2 sensing will be studied in experiments characterizing the stomatal response to CO2 under red light. Arabidopsis mutants will also be used in further studies of an acclimation of the stomatal response to CO2, and a possible role of the xanthophyll cycle of the guard cell chloroplast in acclimations of the stomatal response to CO2. Studies on the osmoregulatory role of sucrose in

  6. Ear Tumors

    ... Japanese Espaniol Find information on medical topics, symptoms, drugs, procedures, news and more, written in everyday language. * This is ... the Ears, Nose, and Throat Additional Content Medical News Ear Tumors ... NOTE: This is the Consumer Version. DOCTORS: Click ...

  7. Ear Disorders

    ... You use all of them in hearing. Sound waves come in through your outer ear. They reach your middle ear, where they make your eardrum vibrate. The vibrations are transmitted through three tiny bones, called ossicles, ...

  8. Elephant ear

    ... Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Elephant ear URL of this page: // Elephant ear To use the sharing features on this page, please enable JavaScript. Elephant ear plants are indoor or outdoor plants with very large, ...

  9. Histochemical and immunohistochemical characterization of exocrine cells in the foregut of the red-eared slider turtle, Trachemys scripta (Emydidae)

    Scillitani, Giovanni; Liquori, Giuseppa Esterina; Mastrodonato, Maria; Ferri, Domenico


    The morphofunctional organization of the exocrine cells in the foregut of the red-eared slider turtle, Trachemys scripta, was investigated by histochemistry (PAS, AB pH1.0 and pH 2.5, HID-AB, Bowie...

  10. XIRP2, an Actin-Binding Protein Essential for Inner Ear Hair-Cell Stereocilia

    Déborah I. Scheffer


    Full Text Available Hair cells of the inner ear are mechanoreceptors for hearing and balance, and proteins highly enriched in hair cells may have specific roles in the development and maintenance of the mechanotransduction apparatus. We identified XIRP2/mXinβ as an enriched protein likely to be essential for hair cells. We found that different isoforms of this protein are expressed and differentially located: short splice forms (also called XEPLIN are targeted more to stereocilia, whereas two long isoforms containing a XIN-repeat domain are in both stereocilia and cuticular plates. Mice lacking the Xirp2 gene developed normal stereocilia bundles, but these degenerated with time: stereocilia were lost and long membranous protrusions emanated from the nearby apical surfaces. At an ultrastructural level, the paracrystalline actin filaments became disorganized. XIRP2 is apparently involved in the maintenance of actin structures in stereocilia and cuticular plates of hair cells, and perhaps in other organs where it is expressed.

  11. The effect of dexamethasone/cell-penetrating peptide nanoparticles on gene delivery for inner ear therapy

    Yoon JY


    Full Text Available Ji Young Yoon,1 Keum-Jin Yang,2 Shi-Nae Park,3 Dong-Kee Kim,3 Jong-Duk Kim1 1Department of Chemical and Biomolecular Engineering, BK 21 Plus Program, Korea Advanced Institute of Science and Technology, Guseong-Dong, Yuseong-Gu, Daejeon, 2Clinical Research Institute, St Mary’s Hospital, Daejeon, 3Department of Otolaryngology – Head and Neck Surgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea Abstract: Dexamethasone (Dex-loaded PHEA-g-C18-Arg8 (PCA nanoparticles (PCA/Dex were developed for the delivery of genes to determine the synergistic effect of Dex on gene expression. The cationic PCA nanoparticles were self-assembled to create cationic micelles containing an octadecylamine (C18 core with Dex and an arginine 8 (Arg8 peptide shell for electrostatic complexation with nucleic acids (connexin 26 [Cx26] siRNA, green fluorescent protein [GFP] DNA or brain-derived neurotrophic factor [BDNF] pDNA. The PCA/Dex nanoparticles conjugated with Arg8, a cell-penetrating peptide that enhances permeability through a round window membrane in the inner ear for gene delivery, exhibited high uptake efficiency in HEI-OC1 cells. This potential carrier co-delivering Dex and the gene into inner ear cells has a diameter of 120–140 nm and a zeta potential of 20–25 mV. Different types of genes were complexed with the Dex-loaded PCA nanoparticle (PCA/Dex/gene for gene expression to induce additional anti-inflammatory effects. PCA/Dex showed mildly increased expression of GFP and lower mRNA expression of inflammatory cytokines (IL1b, IL12, and INFr than did Dex-free PCA nanoparticles and Lipofectamine® reagent in HEI-OC1 cells. In addition, after loading Cx26 siRNA onto the surface of PCA/Dex, Cx26 gene expression was downregulated according to real-time polymerase chain reaction for 24 h, compared with that using Lipofectamine reagent. After loading BDNF DNA into PCA/Dex, increased expression of BDNF was observed for 30

  12. Expression of insulin signalling components in the sensory epithelium of the human saccule

    Degerman, Eva; Rauch, Uwe; Lindberg, Sven


    Several studies have demonstrated a link between diabetes and the dysfunction of the inner ear. Few studies, however, have reported the signalling mechanisms involved in metabolic control in human inner ear cells. Knowledge of the expression and role of the insulin receptor and downstream...... signalling components in the inner ear is sparce. Our immunohistochemistry approach has shown that the insulin receptor, insulin receptor substrate 1 (IRS1), protein kinase B (PKB) and insulin-sensitive glucose transporter (GLUT4) are expressed in the sensory epithelium of the human saccule, which also...... exhibits expression of a calcium-sensitive cAMP/cGMP phosphodiesterase 1C (PDE1C) and the vasopressin type 2 receptor. IRS1 and PDE1C are selectively expressed in sensory epithelial hair cells, whereas the other components are expressed in sensory epithelial supporting cells or in both cell types...

  13. Induction of hair follicle regeneration in rat ear by mi-croencapsulated human hair dermal papilla cells

    LIN Chang-min; LI Yu; JI Ying-chang; HUANG Keng; CAI Xiang-na; LI Guo-qiang


    Objective: To induce hair follicle regeneration in rat ear by microencapsulated dermal papillae (DP) cells.Methods: Intact dermal papillae were obtained from human scalp follicles which were digested with collagenase I. The human hair DP cells were encapsulated with alginate-polylysine-alginate (APA) by a high-voltage electric field droplet generator. The diameters of the DP cell microcapsules were optimized by regulating the voltage, the distance be-tween the needle head and the solution surface and the injection speed. Then DP cell microencapsulations were xenotransplanted into ears of 20 SD rats with a novel method. One rat was killed every week at the postoperative 2-12 weeks and the implantation sites were biopsied for histo-logical observation.Results: The DP cell microencapsulations were found in a group of round, smooth and transparent microcapsules under a phase-contrast microscope. The optimal combina-tion of parameters to obtain 0.4 mm DP cell microcapsules was voltage 7.0 kV, injection speed 55 mm/h, and distance 10mm. After 4-12 weeks, 18 of 20 DP cell microcapsule implan-tations had produced high-density hair. Histological obser-vation indicated that both large follicles and sebaceous gland structures were formed in the rat ear within 3-12 weeks.Conclusions: These findings show that the DP cell microencapsulation maintain the capacity for initiating the follicle regeneration and can be considered as a substitute for fresh isolated dermal papillae.

  14. Pig Induced Pluripotent Stem Cell-Derived Neural Rosettes Parallel Human Differentiation Into Sensory Neural Subtypes.

    Webb, Robin L; Gallegos-Cárdenas, Amalia; Miller, Colette N; Solomotis, Nicholas J; Liu, Hong-Xiang; West, Franklin D; Stice, Steven L


    The pig is the large animal model of choice for study of nerve regeneration and wound repair. Availability of porcine sensory neural cells would conceptually allow for analogous cell-based peripheral nerve regeneration in porcine injuries of similar severity and size to those found in humans. After recently reporting that porcine (or pig) induced pluripotent stem cells (piPSCs) differentiate into neural rosette (NR) structures similar to human NRs, here we demonstrate that pig NR cells could differentiate into neural crest cells and other peripheral nervous system-relevant cell types. Treatment with either bone morphogenetic protein 4 or fetal bovine serum led to differentiation into BRN3A-positive sensory cells and increased expression of sensory neuron TRK receptor gene family: TRKA, TRKB, and TRKC. Porcine sensory neural cells would allow determination of parallels between human and porcine cells in response to noxious stimuli, analgesics, and reparative mechanisms. In vitro differentiation of pig sensory neurons provides a novel model system for neural cell subtype specification and would provide a novel platform for the study of regenerative therapeutics by elucidating the requirements for innervation following injury and axonal survival.

  15. Sensory-Driven Enhancement of Calcium Signals in Individual Purkinje Cell Dendrites of Awake Mice

    Farzaneh Najafi


    Full Text Available Climbing fibers (CFs are thought to contribute to cerebellar plasticity and learning by triggering a large influx of dendritic calcium in the postsynaptic Purkinje cell (PC to signal the occurrence of an unexpected sensory event. However, CFs fire about once per second whether or not an event occurs, raising the question of how sensory-driven signals might be distinguished from a background of ongoing spontaneous activity. Here, we report that in PC dendrites of awake mice, CF-triggered calcium signals are enhanced when the trigger is a sensory event. In addition, we show that a large fraction of the total enhancement in each PC dendrite can be accounted for by an additional boost of calcium provided by sensory activation of a non-CF input. We suggest that sensory stimulation may modulate dendritic voltage and calcium concentration in PCs to increase the strength of plasticity signals during cerebellar learning.

  16. Ear Problems

    ... have cold or flu symptoms?YesNoDo you have tooth pain on the same side as the ear pain ... or 2 days, see your doctor.Start OverDiagnosisA tooth problem can radiate pain to the ear on the same side.Self ...

  17. UV-laser ablation of sensory cells in living insects

    Fuhr, G.; Ronacher, B.; Krahe, R.; Fest, S.; Shirley, S. G.; Rogaschewski, S.

    An experimental set-up for applying pulsed UV-laser ablation to the integument of insects and the high precision of ablation is demonstrated. In order to test for possible detrimental effects on physiological responses, this technique was applied to the ears of migratory locust (Locusta migratoria L.). The handling of living insects, the survival, and physiological response after treatment are described. We selectively interrupted the d-receptor of the tympanal organ, which is the receptor system responsible for the locust's sensitivity in the high-frequency range (>10 kHz). The effects of the laser treatment were tested by determining hearing thresholds in electrophysiological recordings from the tympanal nerves. In agreement with the literature, the interruption of the d-receptors led to a significant shift towards higher values of the thresholds in the high-frequency range. Future perspectives and biological applications of UV-laser ablation are discussed.

  18. External Otitis (Swimmer's Ear)

    ... to Pneumococcal Vaccine Additional Content Medical News External Otitis (Swimmer's Ear) By Bradley W. Kesser, MD, Associate ... the Outer Ear Ear Blockages Ear Tumors External Otitis (Swimmer's Ear) Malignant External Otitis Perichondritis External otitis ...

  19. Ear Infections in Children

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Ear Infections in Children On this page: What is ... additional information about ear infections? What is an ear infection? An ear infection is an inflammation of ...

  20. Airplane Ear

    ... severe hearing loss Ringing in your ear (tinnitus) Spinning sensation (vertigo) Vomiting resulting from vertigo Bleeding from ... the back of the nasal cavity and the top of the throat meet (nasopharynx). When an airplane ...

  1. Characteristics of chloride currents activated by noradrenaline in rabbit ear artery cells.

    Amédée, T; Large, W A; Wang, Q


    1. Responses to noradrenaline were studied in isolated rabbit ear artery cells with the nystatin method of whole-cell patch-clamp recording. With this technique it was possible to obtain reproducible responses to noradrenaline which was not possible with traditional whole-cell recording. 2. With NaCl as the major constituent of the bathing solution (potassium-free pipette and external solutions) the reversal potential (Er) of the noradrenaline-evoked current was about 0 mV. When external chloride was replaced by thiocyanate, iodide, nitrate and bromide, Er was shifted to more negative potentials which indicates that a chloride conductance increase contributes to the current activated by noradrenaline. 3. When sodium was substituted by Tris, N-methyl-D-glucamine, choline or barium, Er of the noradrenaline-evoked current did not alter. This result suggests that a cation conductance is not implicated in the response to noradrenaline recorded with the nystatin method of whole-cell recording. 4. The chloride current activated by noradrenaline was blocked by the selective alpha 1-adrenoceptor antagonist prazosin but was not affected by the alpha 2-adrenoceptor antagonist yohimbine. 5. When cells were exposed to zero calcium bathing solutions the amplitude of the current elicited by noradrenaline was unaffected when measured within 1-2 min in zero calcium conditions. Continued exposure to 0 Ca + 1 mM-EGTA solution reversibly abolished the chloride current to noradrenaline. 6. In the presence of caffeine, which releases Ca2+ from internal stores and itself induced an inward current (at a holding potential of -50 mV), noradrenaline did not elicit a current. These data suggest that the chloride current evoked by noradrenaline results from an increase in intracellular concentration of calcium derived from internal stores. 7. The chloride channel blocking agents 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS; 0.5 mM) and furosemide (0.5 mM) produced partial

  2. Characterization of neural stem cells and their progeny in the sensory circumventricular organs of adult mouse.

    Furube, Eriko; Morita, Mitsuhiro; Miyata, Seiji


    Although evidence has accumulated that neurogenesis and gliogenesis occur in the subventricular zone (SVZ) and subgranular zone (SGZ) of adult mammalian brains, recent studies indicate the presence of neural stem cells (NSCs) in adult brains, particularly the circumventricular regions. In the present study, we aimed to determine characterization of NSCs and their progenitor cells in the sensory circumventricular organs (CVOs), including organum vasculosum of the lamina terminalis, subfornical organ, and area postrema of adult mouse. There were two types of NSCs: tanycyte-like ependymal cells and astrocyte-like cells. Astrocyte-like NSCs proliferated slowly and oligodendrocyte progenitor cells (OPCs) and neural progenitor cells (NPCs) actively divided. Molecular marker protein expression of NSCs and their progenitor cells were similar to those reported in the SVZ and SGZ, except that astrocyte-like NSCs expressed S100β. These circumventricular NSCs possessed the capacity to give rise to oligodendrocytes and sparse numbers of neurons and astrocytes in the sensory CVOs and adjacent brain regions. The inhibition of vascular endothelial growth factor (VEGF) signaling by using a VEGF receptor-associated tyrosine kinase inhibitor AZD2171 largely suppressed basal proliferation of OPCs. A single systemic administration of lipopolysaccharide attenuated proliferation of OPCs and induced remarkable proliferation of microglia. The present study indicates that sensory circumventricular NSCs provide new neurons and glial cells in the sensory CVOs and adjacent brain regions.

  3. LKB1 Is Required for the Development and Maintenance of Stereocilia in Inner Ear Hair Cells in Mice.

    Yuqin Men

    Full Text Available The LKB1 gene, which encodes a serine/threonine kinase, was discovered to play crucial roles in cell differentiation, proliferation, and the establishment of cell polarity. In our study, LKB1 conditional knockout mice (Atoh1-LKB1-/- mice were generated to investigate LKB1 function in the inner ear. Tests of auditory brainstem response and distortion product otoacoustic emissions revealed significant decreases in the hearing sensitivities of the Atoh1-LKB1-/- mice. In Atoh1-LKB1-/- mice, malformations of hair cell stereocilliary bundles were present as early as postnatal day 1 (P1, a time long before the maturation of the hair cell bundles. In addition, we also observed outer hair cell (OHC loss starting at P14. The impaired stereocilliary bundles occurred long before the presence of hair cell loss. Stereociliary cytoskeletal structure depends on the core actin-based cytoskeleton and several actin-binding proteins. By Western blot, we examined actin-binding proteins, specifically ERM (ezrin/radixin/moesin proteins involved in the regulation of the actin cytoskeleton of hair cell stereocilia. Our results revealed that the phosphorylation of ERM proteins (pERM was significantly decreased in mutant mice. Thus, we propose that the decreased pERM may be a key factor for the impaired stereocillia function, and the damaged stereocillia may induce hair cell loss and hearing impairments. Taken together, our data indicates that LKB1 is required for the development and maintenance of stereocilia in the inner ear.

  4. Respiration Gates Sensory Input Responses in the Mitral Cell Layer of the Olfactory Bulb

    Short, Shaina M.; Morse, Thomas M.; McTavish, Thomas S.; Shepherd, Gordon M.; Verhagen, Justus V.


    Respiration plays an essential role in odor processing. Even in the absence of odors, oscillating excitatory and inhibitory activity in the olfactory bulb synchronizes with respiration, commonly resulting in a burst of action potentials in mammalian mitral/tufted cells (MTCs) during the transition from inhalation to exhalation. This excitation is followed by inhibition that quiets MTC activity in both the glomerular and granule cell layers. Odor processing is hypothesized to be modulated by and may even rely on respiration-mediated activity, yet exactly how respiration influences sensory processing by MTCs is still not well understood. By using optogenetics to stimulate discrete sensory inputs in vivo, it was possible to temporally vary the stimulus to occur at unique phases of each respiration. Single unit recordings obtained from the mitral cell layer were used to map spatiotemporal patterns of glomerular evoked responses that were unique to stimulations occurring during periods of inhalation or exhalation. Sensory evoked activity in MTCs was gated to periods outside phasic respiratory mediated firing, causing net shifts in MTC activity across the cycle. In contrast, odor evoked inhibitory responses appear to be permitted throughout the respiratory cycle. Computational models were used to further explore mechanisms of inhibition that can be activated by respiratory activity and influence MTC responses. In silico results indicate that both periglomerular and granule cell inhibition can be activated by respiration to internally gate sensory responses in the olfactory bulb. Both the respiration rate and strength of lateral connectivity influenced inhibitory mechanisms that gate sensory evoked responses. PMID:28005923

  5. Seeing 'where' through the ears: effects of learning-by-doing and long-term sensory deprivation on localization based on image-to-sound substitution.

    Michael J Proulx

    Full Text Available BACKGROUND: Sensory substitution devices for the blind translate inaccessible visual information into a format that intact sensory pathways can process. We here tested image-to-sound conversion-based localization of visual stimuli (LEDs and objects in 13 blindfolded participants. METHODS AND FINDINGS: Subjects were assigned to different roles as a function of two variables: visual deprivation (blindfolded continuously (Bc for 24 hours per day for 21 days; blindfolded for the tests only (Bt and system use (system not used (Sn; system used for tests only (St; system used continuously for 21 days (Sc. The effect of learning-by-doing was assessed by comparing the performance of eight subjects (BtSt who only used the mobile substitution device for the tests, to that of three subjects who, in addition, practiced with it for four hours daily in their normal life (BtSc and BcSc; two subjects who did not use the device at all (BtSn and BcSn allowed assessment of its use in the tasks we employed. The impact of long-term sensory deprivation was investigated by blindfolding three of those participants throughout the three week-long experiment (BcSn, BcSn/c, and BcSc; the other ten subjects were only blindfolded during the tests (BtSn, BtSc, and the eight BtSt subjects. Expectedly, the two subjects who never used the substitution device, while fast in finding the targets, had chance accuracy, whereas subjects who used the device were markedly slower, but showed much better accuracy which improved significantly across our four testing sessions. The three subjects who freely used the device daily as well as during tests were faster and more accurate than those who used it during tests only; however, long-term blindfolding did not notably influence performance. CONCLUSIONS: Together, the results demonstrate that the device allowed blindfolded subjects to increasingly know where something was by listening, and indicate that practice in naturalistic conditions

  6. β3-integrin is required for differentiation in OC-2 cells derived from mammalian embryonic inner ear

    Brunetta Ivan


    Full Text Available Abstract Background The mammalian inner ear contains the organ of Corti which is responsible for the conversion of sound into neuronal signals. This specialised epithelial tissue is the product of a complex developmental process where a common precursor cell type differentiates into the sound transducing hair cells and the non-innervated supporting cells. We hypothesised that integrin proteins, which are involved in cell attachment to extracellular matrix proteins and cellular signalling, play a role in the differentiation process of the precursor inner ear epithelial cells. To test our hypothesis we have utilised a cell line (OC-2 derived from E13 embryonic immortomouse inner ears. In vitro, by switching the incubation temperature from 33°C to 39°C, the OC-2 cells can be induced to differentiate and express hair cells markers, such as Myosin VIIa. The OC-2 cells are thus a useful model system for testing mechanism of hair cells differentiation. Results We have identified 4 integrin subunits which are expressed in OC-2 cells: α6, αv, β1 and β3. Among these, the relative level of expression of the αv, β1 and β3 subunits increased in a time dependent manner when the cells were exposed to the differentiating temperature of 39°C, most notably so for β3 which was not detectable at 33°C. Treatment of fully differentiated OC-2 cells with siRNA against the four integrin subunits reduced the expression of not only the respective integrin proteins but also of the hair cell marker Myosin VIIa. Conversely over-expression of β3 was sufficient to induce the expression of Myosin VIIa at 33°C. Conclusions Our data demonstrate that modulation of integrin expression is associated with the differentiation process of the OC-2 cells. This suggests that the maturation of the organ of Corti, from where OC-2 cells are derived, may also depend on changes of gene expression associated with integrin expression.

  7. Ethanol affects the development of sensory hair cells in larval zebrafish (Danio rerio.

    Phillip M Uribe

    Full Text Available Children born to mothers with substantial alcohol consumption during pregnancy can present a number of morphological, cognitive, and sensory abnormalities, including hearing deficits, collectively known as fetal alcohol syndrome (FAS. The goal of this study was to determine if the zebrafish lateral line could be used to study sensory hair cell abnormalities caused by exposure to ethanol during embryogenesis. Some lateral line sensory hair cells are present at 2 days post-fertilization (dpf and are functional by 5 dpf. Zebrafish embryos were raised in fish water supplemented with varying concentrations of ethanol (0.75%-1.75% by volume from 2 dpf through 5 dpf. Ethanol treatment during development resulted in many physical abnormalities characteristic of FAS in humans. Also, the number of sensory hair cells decreased as the concentration of ethanol increased in a dose-dependent manner. The dye FM 1-43FX was used to detect the presence of functional mechanotransduction channels. The percentage of FM 1-43-labeled hair cells decreased as the concentration of ethanol increased. Methanol treatment did not affect the development of hair cells. The cell cycle markers proliferating cell nuclear antigen (PCNA and bromodeoxyuridine (BrdU demonstrated that ethanol reduced the number of sensory hair cells, as a consequence of decreased cellular proliferation. There was also a significant increase in the rate of apoptosis, as determined by TUNEL-labeling, in neuromasts following ethanol treatment during larval development. Therefore, zebrafish are a useful animal model to study the effects of hair cell developmental disorders associated with FAS.

  8. Successful Treatment of Two Cases of Squamous Cell Carcinoma on the Ear with Intra-Arterial Administration of Peplomycin through a Superficial Temporal Artery

    Takahiro Haga


    Full Text Available Cutaneous squamous cell carcinoma (SCC is the second most common non-melanoma skin cancer and tends to develop in sun-exposed cosmetic areas, including the ear. In this report, we describe two cases of SCC on the ear successfully treated with intra-arterial administration of peplomycin through a superficial temporal artery. In addition to this selective chemotherapy, we administered oral tegafur, which achieved complete remission of the tumor. These findings suggest that intra-arterial administration of peplomycin with tegafur is one of the optimal therapies for the treatment of SCC developing on the ear.

  9. Skeletal muscle cell apoptosis following motornerve injury versus sensory nerve injury

    Lei Zhao; Ruisheng Xu; Shenyang Jiang; Guangming Lü; Zhiqiang Yan; Junming Sun; Ling Wang; Ye Xue; Donglin Jiang


    Skeletal muscle atrophy inevitably occurs in denervated skeletal muscle, and cell apoptosis plays an important role in skeletal muscle atrophy and degeneration. The present study established rat models of simple nerve injury by transecting the ventral or dorsal spinal nerve root and observed rat skeletal muscle cell apoptosis following simple motor nerve injury versus simple sensory nerve injury. Following skeletal muscle denervation for 10 weeks, cell apoptosis was detected in skeletal muscle, which was accompanied by obvious changes in rat behavior and electrophysiological responses. In addition, changes in cross-sectional area and average gray-scale of motor endplates of the gastrocnemius muscle were analyzed following sciatic nerve injury and motor nerve injury.Cell nuclei in denervated skeletal muscle tissue were more densely arranged than in normal skeletal muscle tissue. Cell nuclei were most dense in the sciatic nerve injury group, followed by the motor nerve injury group and the sensory nerve injury group. Fas/Fast expression and the number of apoptotic cells increased in denervated skeletal muscle, and apoptosis-related changes were observed. These findings suggested that motor and sensory nerves provided trophic actions following skeletal muscle and motor nerve injury, resulting in a greater influence on skeletal muscle atrophy than sensory nerve injury. Therefore, reconstruction of motor nerves should be preferentially considered for treating denervation-induced skeletal muscle atrophy.

  10. Glutaraldehyde induces cell shape changes in isolated outer hair cells from the inner ear.

    Slepecky, N; Ulfendahl, M


    Individual isolated outer hair cells (OHCs) from the cochlea were maintained in a collagen gel and viewed in the light microscope. They were observed during fixation and processing for transmission electron microscopy and individual cells were selected for observation in the electron microscope. Application of glutaraldehyde at several concentrations caused OHCs to become shorter. Shrinkage occurred during dehydration but there was no further change during infiltration with the epoxy resin. Ultrastructural analysis of isolated cells fixed with glutaraldehyde and postfixed with osmium tetroxide showed that these cells were similar to cells fixed in the intact cochlea. The glutaraldehyde-induced cell shape change is similar to the shortening seen in intact OHCs in response to the application of solutions containing high potassium or caffeine. Application of glutaraldehyde to cells pretreated with potassium or caffeine caused further shortening. Glutaraldehyde-induced cell shape change was not blocked by the application of tetracaine, which did prevent potassium-induced and caffeine-induced shortening. Glutaraldehyde-induced cell shape change was not stopped by short treatment with N-ethylmaleimide, which did inhibit potassium-induced shortening. Results from these experiments suggest that the glutaraldehyde-induced OHC shape change is not caused by an effect on the membrane or by calcium activation of a contractile response. Shortening may be caused by shrinkage due to cross-linking of proteins.

  11. Communication between neuronal somata and satellite glial cells in sensory ganglia.

    Huang, Li-Yen M; Gu, Yanping; Chen, Yong


    Studies of the structural organization and functions of the cell body of a neuron (soma) and its surrounding satellite glial cells (SGCs) in sensory ganglia have led to the realization that SGCs actively participate in the information processing of sensory signals from afferent terminals to the spinal cord. SGCs use a variety ways to communicate with each other and with their enwrapped soma. Changes in this communication under injurious conditions often lead to abnormal pain conditions. "What are the mechanisms underlying the neuronal soma and SGC communication in sensory ganglia?" and "how do tissue or nerve injuries affect the communication?" are the main questions addressed in this review. Copyright © 2013 Wiley Periodicals, Inc.

  12. CD8 T Cell Sensory Adaptation Dependent on TCR Avidity for Self-Antigens

    Marquez, M.-E.; Ellmeier, W.; Sanchez-Guajardo, Vanesa Maria


    Adaptation of the T cell activation threshold may be one mechanism to control autoreactivity. To investigate its occurrence in vivo, we engineered a transgenic mouse model with increased TCR-dependent excitability by expressing a Zap70 gain-of-function mutant (ZAP-YEEI) in postselection CD8...... dephosphorylation of linker for activation of T cells and ERK upon activation. Normal TCR levels and cytokine production were restored by culturing cells in the absence of TCR/spMHC interaction, demonstrating dynamic tuning of peripheral T cell responses. The effect of avidity for self-ligand(s) on this sensory...... ZAP-YEEI cells were enhanced. Our data provide support for central and peripheral sensory T cell adaptation induced as a function of TCR avidity for self-ligands and signaling level. This may contribute to buffer excessive autoreactivity while optimizing TCR repertoire usage....

  13. Efficient induction of inner ear hair cell-like cells from mouse ES cells using combination of Math1 transfection and conditioned medium from ST2 stromal cells.

    Ouji, Yukiteru; Sakagami, Masaharu; Omori, Hiroko; Higashiyama, Shinji; Kawai, Norikazu; Kitahara, Tadashi; Wanaka, Akio; Yoshikawa, Masahide


    We sought to establish a more efficient technique for induction of inner ear hair cell-like cells (HC-like cells) from embryonic stem cells (ES cells) by using a combination of two previously reported methods; ST2 stromal cell-conditioned medium, known to be favorable for HC-like cell induction (HIST2 method), and ES cells with transfer of the Math1 gene (Math1-ES cells). Math1-ES cells carrying Tet-inducible Math1 were cultured for 14days with doxycycline in conditioned medium from cultures of ST2 stromal cells following formation of 4-day embryoid bodies (EBs). Although each of the previously introduced methods have been reported to induce approximately 20% HC-like cells and 10% HC-like cells in their respective populations in EB outgrowths at the end of the culture periods, the present combined method was able to generate approximately 30% HC-like cells expressing HC-related markers (myosin6, myosin7a, calretinin, α9AchR, Brn3c), which showed remarkable formation of stereocilia-like structures. Analysis of expressions of marker genes specific for cochlear (Lmod3, Emcn) and vestibular (Dnah5, Ptgds) cells indicated that our HIST2 method may lead to induction of cochlear- and vestibular-type cells. In addition, continuous Math1 induction by doxycycline without use of the HIST2 method preferentially induced cochlear markers with negligible effects on vestibular marker induction. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Cell type-specific transcriptome analysis reveals a major role for Zeb1 and miR-200b in mouse inner ear morphogenesis.

    Ronna Hertzano


    Full Text Available Cellular heterogeneity hinders the extraction of functionally significant results and inference of regulatory networks from wide-scale expression profiles of complex mammalian organs. The mammalian inner ear consists of the auditory and vestibular systems that are each composed of hair cells, supporting cells, neurons, mesenchymal cells, other epithelial cells, and blood vessels. We developed a novel protocol to sort auditory and vestibular tissues of newborn mouse inner ears into their major cellular components. Transcriptome profiling of the sorted cells identified cell type-specific expression clusters. Computational analysis detected transcription factors and microRNAs that play key roles in determining cell identity in the inner ear. Specifically, our analysis revealed the role of the Zeb1/miR-200b pathway in establishing epithelial and mesenchymal identity in the inner ear. Furthermore, we detected a misregulation of the ZEB1 pathway in the inner ear of Twirler mice, which manifest, among other phenotypes, malformations of the auditory and vestibular labyrinth. The association of misregulation of the ZEB1/miR-200b pathway with auditory and vestibular defects in the Twirler mutant mice uncovers a novel mechanism underlying deafness and balance disorders. Our approach can be employed to decipher additional complex regulatory networks underlying other hearing and balance mouse mutants.

  15. Sequoia regulates cell fate decisions in the external sensory organs of adult Drosophila.

    Andrews, Hillary K; Giagtzoglou, Nikolaos; Yamamoto, Shinya; Schulze, Karen L; Bellen, Hugo J


    The adult Drosophila external sensory organ (ESO), comprising the hair, socket, neuron, sheath and glia cells, arises through the asymmetric division of sensory organ precursor cells (SOPs). In a mosaic screen designed to identify new components in ESO development, we isolated mutations in sequoia, which encodes a putative zinc-finger transcription factor that has previously been shown to have a role in dendritogenesis. Here, we show that adult clones mutant for seq exhibit a loss of hair cells and a gain of socket cells. We propose that the seq mutant phenotype arises, in part, owing to the loss of several crucial transcription factors known to be important in peripheral nervous system development such as D-Pax2, Prospero and Hamlet. Thus, Sequoia is a new upstream regulator of genes that orchestrates cell fate specification during development of the adult ESO lineage.

  16. Sensory Adaptation in Naive Peripheral CD4 T Cells

    Smith, Katy; Seddon, Benedict; Purbhoo, Marco A.; Zamoyska, Rose; Fisher, Amanda G.; Merkenschlager, Matthias


    T cell receptor interactions with peptide/major histocompatibility complex (pMHC) ligands control the selection of T cells in the thymus as well as their homeostasis in peripheral lymphoid organs. Here we show that pMHC contact modulates the expression of CD5 by naive CD4 T cells in a process that requires the continued expression of p56lck. Reduced CD5 levels in T cells deprived of pMHC contact are predictive of elevated Ca2+ responses to subsequent TCR engagement by anti-CD3 or nominal anti...

  17. Sensory defects in Necdin deficient mice result from a loss of sensory neurons correlated within an increase of developmental programmed cell death

    Fernandez Pierre-Alain


    Full Text Available Abstract Background The human NECDIN gene is involved in a neurodevelopmental disorder, Prader-Willi syndrome (PWS. Previously we reported a mouse Necdin knock-out model with similar defects to PWS patients. Despite the putative roles attributed to Necdin, mainly from in vitro studies, its in vivo function remains unclear. In this study, we investigate sensory-motor behaviour in Necdin deficient mice. We reveal cellular defects and analyse their cause. Results We report sensory differences in Necdin deficient mice compared to wild type animals. These differences led us to investigate sensory neuron development in Necdin deficient mouse embryos. First, we describe the expression pattern of Necdin in developing DRGs and report a reduction of one-third in specified sensory neurons in dorsal roots ganglia and show that this neuronal loss is achieved by E13.5, when DRGs sensory neurons are specified. In parallel, we observed an increase of 41% in neuronal apoptosis during the wave of naturally occurring cell death at E12.5. Since it is assumed that Necdin is a P75NTR interactor, we looked at the P75NTR-expressing cell population in Necdin knock-out embryos. Unexpectedly, Necdin loss of function has no effect on p75NTR expressing neurons suggesting no direct genetic interaction between Necdin and P75NTR in this context. Although we exclude a role of Necdin in axonal outgrowth from spinal sensory neurons in early developmental stages; such a role could occur later in neuronal differentiation. Finally we also exclude an anti-proliferative role of Necdin in developing sensory neurons. Conclusion Overall, our data show clearly that, in early development of the nervous system, Necdin is an anti-apoptotic or survival factor.

  18. Travel Inside the Ear

    Full Text Available ... Info » Hearing, Ear Infections, and Deafness Travel Inside the Ear Video When sound waves reach your ear, ... heard a soft sound or a loud sound. The sound passes through the outer ear and is ...

  19. Ear Plastic Surgery

    ... ENTCareers Marketplace Find an ENT Doctor Near You Ear Plastic Surgery Ear Plastic Surgery Patient Health Information ... they may improve appearance and self-confidence. Can Ear Deformities Be Corrected? Formation of the ear during ...

  20. Autoimmune Inner Ear Disease

    ... Find an ENT Doctor Near You Autoimmune Inner Ear Disease Autoimmune Inner Ear Disease Patient Health Information ... with a hearing loss. How Does the Healthy Ear Work? The ear has three main parts: the ...

  1. Better Ear Health

    ... Marketplace Find an ENT Doctor Near You Better Ear Health Better Ear Health Patient Health Information News ... often helpful to those with this condition. Swimmer’s Ear An infection of the outer ear structures caused ...

  2. How the Ear Works

    ... Find an ENT Doctor Near You How the Ear Works How the Ear Works Patient Health Information News media interested in ... public relations staff at . The ear has three main parts: the outer ear (including ...

  3. Cosmetic ear surgery

    Otoplasty; Ear pinning; Ear surgery - cosmetic; Ear reshaping; Pinnaplasty ... Cosmetic ear surgery may be done in the surgeon's office, an outpatient clinic, or a hospital. It can be performed under ...

  4. Inner ear hair cell regeneration A look from the past to the future

    Francisco Santaolalla; Carlos Salvador; Agustn Martnez; Jose Mara Snchez; Ana Snchez del Rey


    Most recent studies on regeneration of inner ear hair cel s focus on use of stem cel s, gene therapy and neurotrophic factors. Cochlear gene therapy has been successful y used in the treatment of neu-rosensory hearing loss. This suggests that cochlear hair cel regeneration is possible. The objective of this paper is to review research and clinical application of inner near hair cel regeneration.

  5. Mitochondrial peroxiredoxin 3 regulates sensory cell survival in the cochlea.

    Fu-Quan Chen

    Full Text Available This study delineates the role of peroxiredoxin 3 (Prx3 in hair cell death induced by several etiologies of acquired hearing loss (noise trauma, aminoglycoside treatment, age. In vivo, Prx3 transiently increased in mouse cochlear hair cells after traumatic noise exposure, kanamycin treatment, or with progressing age before any cell loss occurred; when Prx3 declined, hair cell loss began. Maintenance of high Prx3 levels via treatment with the radical scavenger 2,3-dihydroxybenzoate prevented kanamycin-induced hair cell death. Conversely, reducing Prx3 levels with Prx3 siRNA increased the severity of noise-induced trauma. In mouse organ of Corti explants, reactive oxygen species and levels of Prx3 mRNA and protein increased concomitantly at early times of drug challenge. When Prx3 levels declined after prolonged treatment, hair cells began to die. The radical scavenger p-phenylenediamine maintained Prx3 levels and attenuated gentamicin-induced hair cell death. Our results suggest that Prx3 is up-regulated in response to oxidative stress and that maintenance of Prx3 levels in hair cells is a critical factor in their susceptibility to acquired hearing loss.

  6. Sensory Adaptation of Dictyostelium discoideum Cells to Chemotactic Signals

    Haastert, Peter J.M. van


    Postvegetative Dictyostelium discoideum cells react chemotactically to gradients of cAMP, folic acid, and pterin. In the presence of a constant concentration of 10-5 M cAMP cells move at random. They still are able to respond to superimposed gradients of cAMP, although the response is less efficient

  7. A cell cycle kinase with tandem sensory PAS domains integrates cell fate cues

    Mann, Thomas H.; Seth Childers, W.; Blair, Jimmy A.; Eckart, Michael R.; Shapiro, Lucy


    All cells must integrate sensory information to coordinate developmental events in space and time. The bacterium Caulobacter crescentus uses two-component phospho-signalling to regulate spatially distinct cell cycle events through the master regulator CtrA. Here, we report that CckA, the histidine kinase upstream of CtrA, employs a tandem-PAS domain sensor to integrate two distinct spatiotemporal signals. Using CckA reconstituted on liposomes, we show that one PAS domain modulates kinase activity in a CckA density-dependent manner, mimicking the stimulation of CckA kinase activity that occurs on its transition from diffuse to densely packed at the cell poles. The second PAS domain interacts with the asymmetrically partitioned second messenger cyclic-di-GMP, inhibiting kinase activity while stimulating phosphatase activity, consistent with the selective inactivation of CtrA in the incipient stalked cell compartment. The integration of these spatially and temporally regulated signalling events within a single signalling receptor enables robust orchestration of cell-type-specific gene regulation. PMID:27117914

  8. A monovalent ion-selective cation current activated by noradrenaline in smooth muscle cells of rabbit ear artery.

    Wang, Q; Hogg, R C; Large, W A


    Membrane currents were recorded with the perforated-patch method with a low-chloride (35 mM) pipette solution in isolated smooth muscle cells of the rabbit ear artery. At a holding potential of -50 mV in potassium-free conditions spontaneous inward single-channel currents were observed and noradrenaline evoked a noisy inward current, which appeared to be comprised of the spontaneous currents. The reversal potential (Vr) of the spontaneous channel and noradrenaline-induced current was not affected in anion-substitution experiments but Vr was altered when external Na+ was replaced with choline or TRIS. The relationship between clamp potential and spontaneous single-channel current amplitude was linear and the mean unitary conductance was 28 pS. Caffeine, which releases calcium from the sarcoplasmic reticulum, and the calcium ionophore ionomycin activated the cation current and also blocked the response to noradrenaline. Spontaneous channel current activity and the noradrenaline-induced current were blocked when external NaCl was replaced with 89 mM CaCl2. The response to noradrenaline was blocked by prazosin but was not affected by yohimbine and therefore the response is mediated by alpha 1-adrenoceptors. It is concluded that in rabbit ear artery smooth muscle cells there is a calcium-activated cation channel of 28 pS conductance, which is relatively impermeable to calcium but can be activated by noradrenaline.

  9. Inner ear morphology in the Atlantic molly Poecilia mexicana--first detailed microanatomical study of the inner ear of a cyprinodontiform species.

    Tanja Schulz-Mirbach

    Full Text Available BACKGROUND: Fishes show an amazing diversity in hearing abilities, inner ear structures, and otolith morphology. Inner ear morphology, however, has not yet been investigated in detail in any member of the diverse order Cyprinodontiformes. We, therefore, studied the inner ear of the cyprinodontiform freshwater fish Poecilia mexicana by analyzing the position of otoliths in situ, investigating the 3D structure of sensory epithelia, and examining the orientation patterns of ciliary bundles of the sensory hair cells, while combining μ-CT analyses, scanning electron microscopy, and immunocytochemical methods. P. mexicana occurs in different ecotypes, enabling us to study the intra-specific variability (on a qualitative basis of fish from regular surface streams, and the Cueva del Azufre, a sulfidic cave in southern Mexico. RESULTS: The inner ear of Poecilia mexicana displays a combination of several remarkable features. The utricle is connected rostrally instead of dorso-rostrally to the saccule, and the macula sacculi, therefore, is very close to the utricle. Moreover, the macula sacculi possesses dorsal and ventral bulges. The two studied ecotypes of P. mexicana showed variation mainly in the shape and curvature of the macula lagenae, in the curvature of the macula sacculi, and in the thickness of the otolithic membrane. CONCLUSIONS: Our study for the first time provides detailed insights into the auditory periphery of a cyprinodontiform inner ear and thus serves a basis--especially with regard to the application of 3D techniques--for further research on structure-function relationships of inner ears within the species-rich order Cyprinodontiformes. We suggest that other poeciliid taxa, or even other non-poeciliid cyprinodontiforms, may display similar inner ear morphologies as described here.

  10. Proteomics and the Inner Ear

    Isolde Thalmann


    Full Text Available The inner ear, one of the most complex organs, contains within its bony shell three sensory systems, the evolutionary oldest gravity receptor system, the three semicircular canals for the detection of angular acceleration, and the auditory system - unrivaled in sensitivity and frequency discrimination. All three systems are susceptible to a host of afflictions affecting the quality of life for all of us. In the first part of this review we present an introduction to the milestones of inner ear research to pave the way for understanding the complexities of a proteomics approach to the ear. Minute sensory structures, surrounded by large fluid spaces and a hard bony shell, pose extreme challenges to the ear researcher. In spite of these obstacles, a powerful preparatory technique was developed, whereby precisely defined microscopic tissue elements can be isolated and analyzed, while maintaining the biochemical state representative of the in vivo conditions. The second part consists of a discussion of proteomics as a tool in the elucidation of basic and pathologic mechanisms, diagnosis of disease, as well as treatment. Examples are the organ of Corti proteins OCP1 and OCP2, oncomodulin, a highly specific calcium-binding protein, and several disease entities, Meniere's disease, benign paroxysmal positional vertigo, and perilymphatic fistula.

  11. Giant Cell Tumor of the Temporal Bone with Direct Invasion into the Middle Ear and Skull Base: A Case Report

    Takashi Iizuka


    Full Text Available Giant cell tumor (GCT is classified as a benign bone tumor, and it is frequently identified at the epiphysis of long bones and relatively rare in the temporal bone. For orthopedists expert at recognizing bone and soft tissue tumors, the diagnosis of GCT is relatively easy; however, since head and neck surgeons experience few cases of GCT, it may be difficult to diagnose when it occurs in the temporal bone. A 32-year-old man complained of left hearing loss, aural fullness, and tinnitus. Examination of the ear revealed a bulging tumor. Audiologic examination demonstrated conductive hearing loss of the left ear. Computer tomograph of the temporal bone showed a soft-tissue-density specification indicating bone destruction at the left temporal bone. The tumor invaded the skull base. Imaging examinations using magnetic resonance imaging revealed a nonhomogenous isosignal intensity area on T1 at the left temporal bone. After intravenous gadolinium, the mass showed unequal enhancement. This patient subsequently underwent surgery to remove the lesion using transmastoid and middle fossa approach. Pathological examinations from specimens of the tumor revealed characteristic of GCT. No clinical or radiological evidence of tumor recurrence was detected for 4 years.

  12. Benign ear cyst or tumor

    Osteomas; Exostoses; Tumor - ear; Cysts - ear; Ear cysts; Ear tumors; Bony tumor of the ear canal ... bony tumors of the ear canal (exostoses and osteomas) are caused by excess growth of bone. Repeated ...

  13. Nitric oxide in guinea pig vestibular sensory cells following gentamicin exposure in vitro.

    Takumida, M; Anniko, M


    Gentamicin-induced production of nitric oxide (NO) in the vestibular end organs of the guinea pig was investigated using the new fluorescence indicator 4,5-diaminofluorescein diacetate for direct detection of NO. Utricular maculae and isolated vestibular sensory cells were examined to locate NO production sites. The fluorescence intensity of the sensory cells was augmented by stimulation with gentamicin. This increase in fluorescence was inhibited by the presence of the non-specific inhibitor for nitric oxide synthase, L-N(G)-nitroarginine methylester, and by the non-specific N-methyl-D-aspartic acid antagonist (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate. These findings indicate that NO may play an important role in the ototoxicity of aminoglycoside.

  14. Basic and clinical physiology of the inner ear receptors and their neural pathways in the brain.

    Sohmer, H; Freeman, S


    The six receptors of the inner ear (cochlea, two otolith organs and three semicircular canals) share a common transduction unit made up of a sensory hair cell, a first order sensory neuron and the synapse between them. Displacement of the stereocilia in a particular direction leads to excitation of the hair cell and activation of the neuron. Electrical and mechanical reflections of these stages of transduction can be recorded non-invasively in humans and in animals. These include cochlear microphonic potentials, otoacoustic emissions, auditory and vestibular evoked potentials. The ability to record these activities can be used to track the development of inner ear function in the fetus and neonate and to study the effects of various ototoxic agents (e.g. noise) and drugs.

  15. Sensory cell proliferation within the olfactory epithelium of developing adult Manduca sexta (Lepidoptera.

    Marie-Dominique Franco

    Full Text Available BACKGROUND: Insects detect a multitude of odors using a broad array of phenotypically distinct olfactory organs referred to as olfactory sensilla. Each sensillum contains one to several sensory neurons and at least three support cells; these cells arise from mitotic activities from one or a small group of defined precursor cells. Sensilla phenotypes are defined by distinct morphologies, and specificities to specific odors; these are the consequence of developmental programs expressed by associated neurons and support cells, and by selection and expression of subpopulations of olfactory genes encoding such proteins as odor receptors, odorant binding proteins, and odor degrading enzymes. METHODOLOGY/PRINCIPAL FINDINGS: We are investigating development of the olfactory epithelium of adult M. sexta, identifying events which might establish sensilla phenotypes. In the present study, antennal tissue was examined during the first three days of an 18 day development, a period when sensory mitotic activity was previously reported to occur. Each antenna develops as a cylinder with an outward facing sensory epithelium divided into approximately 80 repeat units or annuli. Mitotic proliferation of sensory cells initiated about 20-24 hrs after pupation (a.p., in pre-existing zones of high density cells lining the proximal and distal borders of each annulus. These high density zones were observed as early as two hr. a.p., and expanded with mitotic activity to fill the mid-annular regions by about 72 hrs a.p. Mitotic activity initiated at a low rate, increasing dramatically after 40-48 hrs a.p.; this activity was enhanced by ecdysteroids, but did not occur in animals entering pupal diapause (which is also ecdysteroid sensitive. CONCLUSIONS/SIGNIFICANCE: Sensory proliferation initiates in narrow zones along the proximal and distal borders of each annulus; these zones rapidly expand to fill the mid-annular regions. These zones exist prior to any mitotic activity

  16. Role of somatostatin receptor-2 in gentamicin-induced auditory hair cell loss in the Mammalian inner ear.

    Yves Brand

    Full Text Available Hair cells and spiral ganglion neurons of the mammalian auditory system do not regenerate, and their loss leads to irreversible hearing loss. Aminoglycosides induce auditory hair cell death in vitro, and evidence suggests that phosphatidylinositol-3-kinase/Akt signaling opposes gentamicin toxicity via its downstream target, the protein kinase Akt. We previously demonstrated that somatostatin-a peptide with hormone/neurotransmitter properties-can protect hair cells from gentamicin-induced hair cell death in vitro, and that somatostatin receptors are expressed in the mammalian inner ear. However, it remains unknown how this protective effect is mediated. In the present study, we show a highly significant protective effect of octreotide (a drug that mimics and is more potent than somatostatin on gentamicin-induced hair cell death, and increased Akt phosphorylation in octreotide-treated organ of Corti explants in vitro. Moreover, we demonstrate that somatostatin receptor-1 knockout mice overexpress somatostatin receptor-2 in the organ of Corti, and are less susceptible to gentamicin-induced hair cell loss than wild-type or somatostatin-1/somatostatin-2 double-knockout mice. Finally, we show that octreotide affects auditory hair cells, enhances spiral ganglion neurite number, and decreases spiral ganglion neurite length.

  17. Development and Integration of the Ear.

    Fuchs, Jennifer C; Tucker, Abigail S


    The perception of our environment via sensory organs plays a crucial role in survival and evolution. Hearing, one of our most developed senses, depends on the proper function of the auditory system and plays a key role in social communication, integration, and learning ability. The ear is a composite structure, comprised of the external, middle, and inner ear. During development, the ear is formed from the integration of a number of tissues of different embryonic origin, which initiate in distinct areas of the embryo at different time points. Functional connections between the components of the hearing apparatus have to be established and maintained during development and adulthood to allow proper sound submission from the outer to the middle and inner ear. This highly organized and intimate connectivity depends on intricate spatiotemporal signaling between the various tissues that give rise to the structures of the ear. Any alterations in this chain of events can lead to the loss of integration, which can subsequently lead to conductive hearing loss, in case of outer and middle ear defects or sensorineural hearing loss, if inner ear structures are defective. This chapter aims to review the current knowledge concerning the development of the three ear compartments as well as mechanisms and signaling pathways that have been implicated in the coordination and integration process of the ear.

  18. Gfi1Cre mice have early onset progressive hearing loss and induce recombination in numerous inner ear non-hair cells

    Matern, Maggie; Vijayakumar, Sarath; Margulies, Zachary; Milon, Beatrice; Song, Yang; Elkon, Ran; Zhang, Xiaoyu; Jones, Sherri M.; Hertzano, Ronna


    Studies of developmental and functional biology largely rely on conditional expression of genes in a cell type-specific manner. Therefore, the importance of specificity and lack of inherent phenotypes for Cre-driver animals cannot be overemphasized. The Gfi1Cre mouse is commonly used for conditional hair cell-specific gene deletion/reporter gene activation in the inner ear. Here, using immunofluorescence and flow cytometry, we show that the Gfi1Cre mice produce a pattern of recombination that is not strictly limited to hair cells within the inner ear. We observe a broad expression of Cre recombinase in the Gfi1Cre mouse neonatal inner ear, primarily in inner ear resident macrophages, which outnumber the hair cells. We further show that heterozygous Gfi1Cre mice exhibit an early onset progressive hearing loss as compared with their wild-type littermates. Importantly, vestibular function remains intact in heterozygotes up to 10 months, the latest time point tested. Finally, we detect minor, but statistically significant, changes in expression of hair cell-enriched transcripts in the Gfi1Cre heterozygous mice cochleae compared with their wild-type littermate controls. Given the broad use of the Gfi1Cre mice, both for gene deletion and reporter gene activation, these data are significant and necessary for proper planning and interpretation of experiments. PMID:28181545

  19. The paratympanic organ: a barometer and altimeter in the middle ear of birds?

    von Bartheld, Christopher S; Giannessi, Francesco


    A century has passed since the discovery of the paratympanic organ (PTO), a mechanoreceptive sense organ in the middle ear of birds and other tetrapods. This luminal organ contains a sensory epithelium with typical mechanosensory hair cells and may function as a barometer and altimeter. The organ is arguably the most neglected sense organ in living tetrapods. The PTO is believed to be homologous to a lateral line sense organ, the spiracular sense organ of nonteleostean fishes. Our review summarizes the current state of knowledge of the PTO and draws attention to the astounding lack of information about the unique and largely unexplored sensory modality of barometric perception.

  20. Microbial cell-free extracts affect the biochemical characteristics and sensorial quality of sourdough bread.

    Cavallo, Noemi; De Angelis, Maria; Calasso, Maria; Quinto, Maurizio; Mentana, Annalisa; Minervini, Fabio; Cappelle, Stefan; Gobbetti, Marco


    This study aimed to improve the sensorial quality of sourdough wheat bread by the addition of cell-free enzyme extracts (CFEs) from Lactobacillus sanfranciscensis (SF), Hafnia alvei (HF) and Debaryomyces hansenii (DH). CFEs were suitable sources of peptidases, glutamate dehydrogenase and cystathionine γ-lyase. The concentration of free amino acids (FAA) in the sourdoughs containing CFEs was higher than the control sourdough, produced without addition of CFEs. The community-level catabolic profiles showed that the highest number of carbohydrates, polymers and carboxylic acids were consumed in the SF sourdough. Breads produced with CFEs were characterized by higher specific volume than the control. The use of CFEs impacted on the profile of volatile organic compounds. Overall, positive correlations were found between some key-aroma compounds and enzyme activities/precursor FAA. The SF bread, characterized by highest level of alcohols, received the highest score for aroma and sweetness in the sensory analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The effect of hair bundle shape on hair bundle hydrodynamics of inner ear hair cells at low and high frequencies.

    Shatz, L F


    The relationship between size and shape of the hair bundle of a hair cell in the inner ear and its sensitivity at asymptotically high and low frequencies was determined, thereby extending the results of an analysis of hair bundle hydrodynamics in two dimensions (Freeman and Weiss, 1990. Hydrodynamic analysis of a two-dimensional model for micromechanical resonance of free-standing hair bundles. Hear. Res. 48, 37-68) to three dimensions. A hemispheroid was used to represent the hair bundle. The hemispheroid had a number of advantages: it could represent shapes that range from thin, pencil-like shapes, to wide, flat, disk-like shapes. Also analytic methods could be used in the high frequency range to obtain an exact solution to the equations of motion. In the low frequency range, where an approximate solution was found using boundary element methods, the sensitivity of the responses of hair cells was mainly proportional to the cube of the heights of their hair bundles, and at high frequencies, the sensitivity of the hair cells was mainly proportional to the inverse of their heights. An excellent match was obtained between measurements of sensitivity curves in the basillar papilla of the alligator and bobtail lizards and the model's predictions. These results also suggest why hair bundles of hair cells in vestibular organs which are sensitive to low frequencies have ranges of heights that are an order of magnitude larger than the range of heights of hair bundles of hair cells found in auditory organs.

  2. Ear infection - chronic

    Middle ear infection - chronic; Otitis media - chronic; Chronic otitis media; Chronic ear infection ... up. When this happens, infection can occur. A chronic ear infection develops when fluid or an infection ...

  3. Travel Inside the Ear

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Travel Inside the Ear Video When sound waves reach ... are smaller than an orange seed. It then travels into the inner ear, which is filled with ...

  4. Ear tube insertion - slideshow

    ... this page: // Ear tube insertion - series—Normal anatomy To use the ... 4 Overview The eardrum (tympanic membrane) separates the ear canal from the middle ear. Review Date 8/ ...

  5. TRPV4 in the sensory organs of adult zebrafish.

    Amato, V; Viña, E; Calavia, M G; Guerrera, M C; Laurà, R; Navarro, M; De Carlos, F; Cobo, J; Germanà, A; Vega, J A


    TRPV4 is a nonselective cation channel that belongs to the vanilloid (V) subfamily of transient receptor potential (TRP) ion channels. While TRP channels have been found to be involved in sensing temperature, light, pressure, and chemical stimuli, TPRV4 is believed to be primarily a mechanosensor although it can also respond to warm temperatures, acidic pH, and several chemical compounds. In zebrafish, the expression of trpv4 has been studied during embryonic development, whereas its pattern of TPRV4 expression during the adult life has not been thoroughly analyzed. In this study, the occurrence of TRPV4 was addressed in the zebrafish sensory organs at the mRNA (RT-PCR) and protein (Westernblot) levels. Once the occurrence of TRPV4 was demonstrated, the TRPV4 positive cells were identified by using immunohistochemistry. TPRV4 was detected in mantle and sensory cells of neuromasts, in a subpopulation of hair sensory cells in the macula and in the cristae ampullaris of the inner ear, in sensory cells in the taste buds, in crypt neurons and ciliated sensory neurons of the olfactory epithelium, and in cells of the retina. These results demonstrate the presence of TRPV4 in all sensory organs of adult zebrafish and are consistent with the multiple physiological functions suspected for TRPV4 in mammals (mechanosensation, hearing, and temperature sensing), but furthermore suggest potential roles in olfaction and vision in zebrafish.

  6. A two-step mechanism underlies the planar polarization of regenerating sensory hair cells.

    López-Schier, Hernán; Hudspeth, A J


    The restoration of planar cell polarity is an essential but poorly understood step toward physiological recovery during sensory-organ regeneration. Investigating this issue in the lateral line of the zebrafish, we found that hair cells regenerate in pairs along a single axis established by the restricted localization and oriented division of their progenitors. By analyzing mutants lacking the planar-polarity determinant Vangl2, we ascertained that the uniaxial production of hair cells and the subsequent orientation of their hair bundles are controlled by distinct pathways, whose combination underlies the establishment of hair-cell orientation during development and regeneration. This mechanism may represent a general principle governing the long-term maintenance of planar cell polarity in remodeling epithelia.

  7. Effect of voltage dynamics on response properties in a model of sensory hair cell

    Amro, Rami


    Sensory hair cells in auditory and vestibular organs rely on active mechanisms to achieve high sensitivity and frequency selectivity. Recent experimental studies have documented self-sustained oscillations in hair cells of lower vertebrates on two distinct levels. First, the hair bundle can undergo spontaneous mechanical oscillations. Second, somatic electric voltage oscillations across the baso-lateral membrane of the hair cell have been observed. We develop a biophysical model of the bullfrog's saccular hair cell consisting of two compartments, mechanical and electrical, to study how the mechanical and the voltage oscillations interact to produce coherent self-sustained oscillations and how this interaction contributes to the overall sensitivity and selectivity of the hair cell. The model incorporates nonlinear mechanical stochastic hair bundle system coupled bi-directionally to a Hodgkin-Huxley type system describing somatic ionic currents. We isolate regions of coherent spontaneous oscillations in the par...

  8. Synaptic communication and signal processing among sensory cells in taste buds

    Chaudhari, Nirupa


    Taste buds (sensory structures embedded in oral epithelium) show a remarkable diversity of transmitters synthesized and secreted locally. The known transmitters accumulate in a cell type selective manner, with 5-HT and noradrenaline being limited to presynaptic cells, GABA being synthesized in both presynaptic and glial-like cells, and acetylcholine and ATP used for signalling by receptor cells. Each of these transmitters participates in local negative or positive feedback circuits that target particular cell types. Overall, the role of ATP is the best elucidated. ATP serves as a principal afferent transmitter, and also is the key trigger for autocrine positive feedback and paracrine circuits that result in potentiation (via adenosine) or inhibition (via GABA or 5-HT). While many of the cellular receptors and mechanisms for these circuits are known, their impact on sensory detection and perception remains to be elaborated in most instances. This brief review examines what is known, and some of the open questions and controversies surrounding the transmitters and circuits of the taste periphery. PMID:24665098

  9. Hearing Loss Controlled by Optogenetic Stimulation of Nonexcitable Nonglial Cells in the Cochlea of the Inner Ear

    Mitsuo P. Sato


    Full Text Available Light-gated ion channels and transporters have been applied to a broad array of excitable cells including neurons, cardiac myocytes, skeletal muscle cells and pancreatic β-cells in an organism to clarify their physiological and pathological roles. Nonetheless, among nonexcitable cells, only glial cells have been studied in vivo by this approach. Here, by optogenetic stimulation of a different nonexcitable cell type in the cochlea of the inner ear, we induce and control hearing loss. To our knowledge, deafness animal models using optogenetics have not yet been established. Analysis of transgenic mice expressing channelrhodopsin-2 (ChR2 induced by an oligodendrocyte-specific promoter identified this channel in nonglial cells—melanocytes—of an epithelial-like tissue in the cochlea. The membrane potential of these cells underlies a highly positive potential in a K+-rich extracellular solution, endolymph; this electrical property is essential for hearing. Illumination of the cochlea to activate ChR2 and depolarize the melanocytes significantly impaired hearing within a few minutes, accompanied by a reduction in the endolymphatic potential. After cessation of the illumination, the hearing thresholds and potential returned to baseline during several minutes. These responses were replicable multiple times. ChR2 was also expressed in cochlear glial cells surrounding the neuronal components, but slight neural activation caused by the optical stimulation was unlikely to be involved in the hearing impairment. The acute-onset, reversible and repeatable phenotype, which is inaccessible to conventional gene-targeting and pharmacological approaches, seems to at least partially resemble the symptom in a population of patients with sensorineural hearing loss. Taken together, this mouse line may not only broaden applications of optogenetics but also contribute to the progress of translational research on deafness.

  10. Single-Cell Memory Regulates a Neural Circuit for Sensory Behavior

    Kyogo Kobayashi


    Full Text Available Unveiling the molecular and cellular mechanisms underlying memory has been a challenge for the past few decades. Although synaptic plasticity is proven to be essential for memory formation, the significance of “single-cell memory” still remains elusive. Here, we exploited a primary culture system for the analysis of C. elegans neurons and show that a single thermosensory neuron has an ability to form, retain, and reset a temperature memory. Genetic and proteomic analyses found that the expression of the single-cell memory exhibits inter-individual variability, which is controlled by the evolutionarily conserved CaMKI/IV and Raf pathway. The variable responses of a sensory neuron influenced the neural activity of downstream interneurons, suggesting that modulation of the sensory neurons ultimately determines the behavioral output in C. elegans. Our results provide proof of single-cell memory and suggest that the individual differences in neural responses at the single-cell level can confer individuality.

  11. Protective Effect of Hexane and Ethanol Extract of Piper Longum L. on Gentamicin-Induced Hair Cell Loss in Neonatal Cultures

    Yadav, Mukesh Kumar; Choi, June; Song, Jae-Jun


    Gentamicin (GM) is a commonly used aminoglycoside antibiotic that generates free oxygen radicals within the inner ear, which can cause vestibulo-cochlear toxicity and permanent damage to the sensory hair cells and neurons. L. (PL...

  12. Molecular bases of K+ secretory cells in the inner ear: shared and distinct features between birds and mammals

    Wilms, Viviane; Köppl, Christine; Söffgen, Chris; Hartmann, Anna-Maria; Nothwang, Hans Gerd


    In the cochlea, mammals maintain a uniquely high endolymphatic potential (EP), which is not observed in other vertebrate groups. However, a high [K+] is always present in the inner ear endolymph. Here, we show that Kir4.1, which is required in the mammalian stria vascularis to generate the highly positive EP, is absent in the functionally equivalent avian tegmentum vasculosum. In contrast, the molecular repertoire required for K+ secretion, specifically NKCC1, KCNQ1, KCNE1, BSND and CLC-K, is shared between the tegmentum vasculosum, the vestibular dark cells and the marginal cells of the stria vascularis. We further show that in barn owls, the tegmentum vasculosum is enlarged and a higher EP (~+34 mV) maintained, compared to other birds. Our data suggest that both the tegmentum vasculosum and the stratified stria vascularis evolved from an ancestral vestibular epithelium that already featured the major cell types of the auditory epithelia. Genetic recruitment of Kir4.1 specifically to strial melanocytes was then a crucial step in mammalian evolution enabling an increase in the cochlear EP. An increased EP may be related to high-frequency hearing, as this is a hallmark of barn owls among birds and mammals among amniotes. PMID:27680950

  13. In vitro culture of ear fibroblast cells from Lu-chuan pig%陆川猪耳部成纤维细胞的体外培养

    秦小娥; 胡林林; 卢晟盛; 卢克焕


    In order to establish an isolation method and culture system for Lu-chuan pig ear fibroblast cells,Lu-chuan pig ear fibroblast cell was isolated and cultured by tissue-piece methods.Using 0.25% trypsin + 0.02% EDTA as digested medium and DMEM containing 10% FBS as culture medium for subculture,it was concluded that culture system was good enough for lu-chuan pig ear fibroblast cells.The pured fibroblast cells could be obtained after passing 3 subcultures.The cultured cells were typical fibroblast morphology,which grooved as irregular triangle or shuttle,appearing as radioactive blaze and helix in shape.The cell type was identified by fluorescent immuneocytochemistry(ICC) and the result indicated that isolated cells from Lu-chuan ear tissues were Lu-chuan ear fibroblast cells.In conclusion,Lu-chuan pig ear fibroblast cell could be isolated and cultured by tissue-piece methods.%本研究建立陆川猪耳部成纤维细胞的体外培养体系,采用组织块培养法可以获得陆川猪耳部成纤维细胞。用0.25%胰蛋白酶+0.02%EDTA消化液消化细胞、用含有10%FBS的DMEM对细胞进行培养,能很好的支持陆川猪耳部成纤维细胞的生长。传3代后,观察到培养的细胞形态逐渐均一,为典型的成纤维细胞,绝大部分呈梭形或不规则三角形。细胞生长时呈放射状、火焰状或旋涡状走势。用间接免疫荧光法对细胞类型进行鉴定。抗波形蛋白免疫荧光染色显示为阳性,抗角形蛋白免疫荧光染色为阴性。结果,分离得到的细胞为成纤维细胞。结果表明,用组

  14. CaMK-II activation is essential for zebrafish inner ear development and acts through Delta-Notch signaling.

    Rothschild, Sarah C; Lahvic, Jamie; Francescatto, Ludmila; McLeod, Jamie J A; Burgess, Shawn M; Tombes, Robert M


    Zebrafish inner ear development is characterized by the crystallization of otoliths onto immotile kinocilia that protrude from sensory "hair" cells. The stereotypical formation of these sensory structures is dependent on the expression of key patterning genes and on Ca2+ signals. One potential target of Ca2+ signaling in the inner ear is the type II Ca2+/calmodulin-dependent protein kinase (CaMK-II), which is preferentially activated in hair cells, with intense activation at the base of kinocilia. In zebrafish, CaMK-II is encoded by seven genes; the expression of one of these genes (camk2g1) is enriched in hair cells. The suppression of camk2g1 expression by antisense morpholino oligonucleotides or inhibition of CaMK-II activation by the pharmacological antagonist, KN-93, results in aberrant otolith formation without preventing cilia formation. In fact, CaMK-II suppression results in additional ciliated hair cells and altered levels of Delta-Notch signaling members. DeltaA and deltaD transcripts are increased and DeltaD protein accumulates in hair cells of CaMK-II morphants, indicative of defective recycling and/or exocytosis. Our findings indicate that CaMK-II plays a critical role in the developing ear, influencing cell differentiation through extranuclear effects on Delta-Notch signaling. Continued expression and activation of CaMK-II in maculae and cristae in older embryos suggests continued roles in auditory sensory maturation and transduction.

  15. Sensory neurons do not induce motor neuron loss in a human stem cell model of spinal muscular atrophy.

    Schwab, Andrew J; Ebert, Allison D


    Spinal muscular atrophy (SMA) is an autosomal recessive disorder leading to paralysis and early death due to reduced SMN protein. It is unclear why there is such a profound motor neuron loss, but recent evidence from fly and mouse studies indicate that cells comprising the whole sensory-motor circuit may contribute to motor neuron dysfunction and loss. Here, we used induced pluripotent stem cells derived from SMA patients to test whether sensory neurons directly contribute to motor neuron loss. We generated sensory neurons from SMA induced pluripotent stem cells and found no difference in neuron generation or survival, although there was a reduced calcium response to depolarizing stimuli. Using co-culture of SMA induced pluripotent stem cell derived sensory neurons with control induced pluripotent stem cell derived motor neurons, we found no significant reduction in motor neuron number or glutamate transporter boutons on motor neuron cell bodies or neurites. We conclude that SMA sensory neurons do not overtly contribute to motor neuron loss in this human stem cell system.

  16. In vitro differentiation of quail neural crest cells into sensory-like neuroblasts

    Sieber-Blum, Maya; Kumar, Sanjiv R.; Riley, Danny A.


    Data are presented that demonstrate the ability of quail neural-crest embrionic cells grown as primary culture to differentiate in vitro into sensorylike neuroblasts. After 7-14 days of growth as primary culture, many of the putative sensory neuroblasts displayed substance P (SP)-like immunoreactivity and some exhibited histochemical carbonic anhydrase activity. Double staining experiments showed that the SP-like immunoreactive neuroblasts did not contain detectable levels of tyrosine hydroxylase or dopamine-beta-hydroxylase. The neuronal nature of the cultured sensorylike neuroblasts was further documented by double labeling for antibodies against the 68 kDa neurofilament polypeptide and substance P.

  17. Diversity in cell motility reveals the dynamic nature of the formation of zebrafish taste sensory organs.

    Soulika, Marina; Kaushik, Anna-Lila; Mathieu, Benjamin; Lourenço, Raquel; Komisarczuk, Anna Z; Romano, Sebastian Alejo; Jouary, Adrien; Lardennois, Alicia; Tissot, Nicolas; Okada, Shinji; Abe, Keiko; Becker, Thomas S; Kapsimali, Marika


    Taste buds are sensory organs in jawed vertebrates, composed of distinct cell types that detect and transduce specific taste qualities. Taste bud cells differentiate from oropharyngeal epithelial progenitors, which are localized mainly in proximity to the forming organs. Despite recent progress in elucidating the molecular interactions required for taste bud cell development and function, the cell behavior underlying the organ assembly is poorly defined. Here, we used time-lapse imaging to observe the formation of taste buds in live zebrafish larvae. We found that tg(fgf8a.dr17)-expressing cells form taste buds and get rearranged within the forming organs. In addition, differentiating cells move from the epithelium to the forming organs and can be displaced between developing organs. During organ formation, tg(fgf8a.dr17) and type II taste bud cells are displaced in random, directed or confined mode relative to the taste bud they join or by which they are maintained. Finally, ascl1a activity in the 5-HT/type III cell is required to direct and maintain tg(fgf8a.dr17)-expressing cells into the taste bud. We propose that diversity in displacement modes of differentiating cells acts as a key mechanism for the highly dynamic process of taste bud assembly.

  18. Inducible transcript expressed by reactive epithelial cells at sites of olfactory sensory neuron proliferation.

    Stoss, Thomas D; Nickell, Melissa D; Hardin, Debra; Derby, Charles D; McClintock, Timothy S


    The continuous replacement of cells in the spiny lobster olfactory organ depends on proliferation of new cells at a specific site, the proximal proliferation zone (PPZ). Using representational difference analysis of cDNA, we identified transcripts enriched in the PPZ compared to the mature zone (MZ) of the organ. The 12 clones identified included four novel sequences, three exoskeletal proteins, a serine protease, two protease inhibitors, a putative growth factor, and a sequence named PET-15 that has similarity to antimicrobial proteins of the crustin type. PET-15 mRNA was only detected in epithelial cells. It was abundant in all epithelial cells of the PPZ, but was only detected in the MZ at sites of damage to the olfactory organ. PET-15 mRNA was increased by types of damage that are known to induce proliferation of new olfactory sensory neurons in the olfactory organ. It increased in the PPZ after partial ablation of the olfactory organ and in the MZ after shaving of aesthetasc sensilla. These ipsilateral effects were mirrored by smaller increases in the undamaged contralateral olfactory organ. These contralateral effects are most parsimoniously explained by the action of a diffusible signal. Because epithelial cells are the source of proliferating progenitors in the olfactory organ, the same diffusible signal may stimulate increases in both cellular proliferation and PET-15 mRNA. The uniformity of expression of PET-15 in the PPZ epithelium suggests that the epithelial cells that give rise to new olfactory sensory neurons are a subset of cells that express PET-15.

  19. Play it by Ear

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren Helstrup; Thaysen, Jesper


    The first antenna for ear-to-ear communication with a standard Bluetooth chip has the potential to improve hearing aid technology.......The first antenna for ear-to-ear communication with a standard Bluetooth chip has the potential to improve hearing aid technology....

  20. A biophysical signature of network affiliation and sensory processing in mitral cells

    Angelo, Kamilla; Rancz, Ede A; Pimentel, Diogo


    , the substantial biophysical diversity of neurons of the same morphological class is typically averaged out and ignored. Here we show that the amplitude of hyperpolarization-evoked sag of membrane potential recorded in olfactory bulb mitral cells is an emergent, homotypic property of local networks and sensory......One defining characteristic of the mammalian brain is its neuronal diversity. For a given region, substructure, layer or even cell type, variability in neuronal morphology and connectivity persists. Although it is well known that such cellular properties vary considerably according to neuronal type...... receptor is universally expressed. Population diversity in this intrinsic property therefore reflects differential expression between local mitral cell networks processing distinct odour-related information....

  1. Aqueous and Methanolic Extracts of Caulerpa mexicana Suppress Cell Migration and Ear Edema Induced by Inflammatory Agents

    Bitencourt, Mariana Angelica Oliveira; Dantas, Gracielle Rodrigues; Lira, Daysianne Pereira; Barbosa-Filho, Jose Maria; de Miranda, George Emmanuel Cavalcanti; de Oliveira Santos, Barbara Viviana; Souto, Janeusa Trindade


    The regulation of the inflammatory response is essential to maintaining homeostasis. Several studies have investigated new drugs that may contribute to avoiding or minimizing excessive inflammatory process. The aim of this study was to evaluate the effect of extracts of green algae Caulerpa mexicana on models inflammation. In mice, the inflammatory peritonitis model is induced by zymosan. Previous treatment of mice with aqueous and methanolic extracts of C. mexicana was able to suppress the cell migration to the peritoneal cavity, in a time-dependent but not in a dose-dependent manner. The treatment of mice with C. mexicana extracts also decreased the xylene-induced ear edema, exerting strong inhibitory leukocyte migration elicited by zymosan into the air pouch. We concluded that administration of the extracts resulted in a reduction of cell migration to different sites as well as a decrease in edema formation induced by chemical irritants. This study demonstrates for the first time the anti-inflammatory effect of aqueous and methanolic extracts from the green marine algae Caulerpa mexicana. PMID:21892348

  2. Connectivity from OR37 expressing olfactory sensory neurons to distinct cell types in the hypothalamus

    Andrea eBader


    Full Text Available Olfactory sensory neurons which express a member from the OR37 subfamily of odorant receptor genes are wired to the main olfactory bulb in a unique monoglomerular fashion; from these glomeruli an untypical connectivity into higher brain centers exists. In the present study we have investigated by DiI and transsynaptic tracing approaches how the connection pattern from these glomeruli into distinct hypothalamic nuclei is organized. The application of DiI onto the ventral domain of the bulb which harbors the OR37 glomeruli resulted in the labeling of fibers within the paraventricular and supraoptic nucleus of the hypothalamus; some of these fibers were covered with varicose-like structures. No DiI-labeled cell somata were detectable in these nuclei. The data indicate that projection neurons which originate in the OR37 region of the main olfactory bulb form direct connections into these nuclei. The cells that were labeled by the transsynaptic tracer WGA in these nuclei were further characterized. Their distribution pattern in the paraventricular nucleus was reminiscent of cells which produce distinct neuropeptides. Double labeling experiments confirmed that they contained vasopressin, but not the related neuropeptide oxytocin. Morphological analysis revealed that they comprise of magno- and parvocellular cells. A comparative investigation of the WGA-positive cells in the supraoptic nucleus demonstrated that these were vasopressin-positive, as well, whereas oxytocin-producing cells of this nucleus also contained no transsynaptic tracer. Together, the data demonstrate a connectivity from OR37 expressing sensory neurons to distinct hypothalamic neurons with the same neuropeptide content.

  3. Morphology, innervation, and peripheral sensory cells of the siphon of aplysia californica.

    Carrigan, Ian D; Croll, Roger P; Wyeth, Russell C


    The siphon of Aplysia californica has several functions, including involvement in respiration, excretion, and defensive inking. It also provides sensory input for defensive withdrawals that have been studied extensively to examine mechanisms that underlie learning. To better understand the neuronal bases of these functions, we used immunohistochemistry to catalogue peripheral cell types and innervation of the siphon in stage 12 juveniles (chosen to allow observation of tissues in whole-mounts). We found that the siphon nerve splits into three major branches, leading ultimately to a two-part FMRFamide-immunoreactive plexus and an apparently separate tyrosine hydroxylase-immunoreactive plexus. Putative sensory neurons included four distinct types of tubulin-immunoreactive bipolar cells (one likely also tyrosine hydroxylase immunoreactive) that bore ciliated dendrites penetrating the epithelium. A fifth bipolar neuron type (tubulin- and FMRFamide-immunoreactive) occurred deeper in the tissue, associated with part of the FMRFamide-immunoreactive plexus. Our observations emphasize the structural complexity of the peripheral nervous system of the siphon, and the importance of direct tests of the various components to better understand the functioning of the entire organ, including its role in defensive withdrawal responses.

  4. Conversion of neurons and glia to external-cell fates in the external sensory organs of Drosophila hamlet mutants by a cousin-cousin cell-type respecification.

    Moore, Adrian W; Roegiers, Fabrice; Jan, Lily Y; Jan, Yuh-Nung


    The Drosophila external sensory organ forms in a lineage elaborating from a single precursor cell via a stereotypical series of asymmetric divisions. HAMLET transcription factor expression demarcates the lineage branch that generates two internal cell types, the external sensory neuron and thecogen. In HAMLET mutant organs, these internal cells are converted to external cells via an unprecedented cousin-cousin cell-fate respecification event. Conversely, ectopic HAMLET expression in the external cell branch leads to internal cell production. The fate-determining signals NOTCH and PAX2 act at multiple stages of lineage elaboration and HAMLET acts to modulate their activity in a branch-specific manner.

  5. Synergistic effect of interleukin 1 alpha on nontypeable Haemophilus influenzae-induced up-regulation of human beta-defensin 2 in middle ear epithelial cells

    Park Raekil


    Full Text Available Abstract Background We recently showed that beta-defensins have antimicrobial activity against nontypeable Haemophilus influenzae (NTHi and that interleukin 1 alpha (IL-1 alpha up-regulates the transcription of beta-defensin 2 (DEFB4 according to new nomenclature of the Human Genome Organization in human middle ear epithelial cells via a Src-dependent Raf-MEK1/2-ERK signaling pathway. Based on these observations, we investigated if human middle ear epithelial cells could release IL-1 alpha upon exposure to a lysate of NTHi and if this cytokine could have a synergistic effect on beta-defensin 2 up-regulation by the bacterial components. Methods The studies described herein were carried out using epithelial cell lines as well as a murine model of acute otitis media (OM. Human cytokine macroarray analysis was performed to detect the released cytokines in response to NTHi exposure. Real time quantitative PCR was done to compare the induction of IL-1 alpha or beta-defensin 2 mRNAs and to identify the signaling pathways involved. Direct activation of the beta-defensin 2 promoter was monitored using a beta-defensin 2 promoter-Luciferase construct. An IL-1 alpha blocking antibody was used to demonstrate the direct involvement of this cytokine on DEFB4 induction. Results Middle ear epithelial cells released IL-1 alpha when stimulated by NTHi components and this cytokine acted in an autocrine/paracrine synergistic manner with NTHi to up-regulate beta-defensin 2. This synergistic effect of IL-1 alpha on NTHi-induced beta-defensin 2 up-regulation appeared to be mediated by the p38 MAP kinase pathway. Conclusion We demonstrate that IL-1 alpha is secreted by middle ear epithelial cells upon exposure to NTHi components and that it can synergistically act with certain of these molecules to up-regulate beta-defensin 2 via the p38 MAP kinase pathway.

  6. Primary radical radiotherapy for squamous cell carcinoma of the middle ear and external auditory cana--an historical series.

    Pemberton, L S; Swindell, R; Sykes, A J


    To evaluate patients treated with radical radiotherapy alone for squamous cell carcinoma of the middle ear (MEC) and external auditory canal (EAC) in terms of freedom from local recurrence, cancer-specific survival and morbidity. Between 1965 and 1988, 123 patients were treated, 70 with MEC and 53 with EAC. The median age was 64 years (range 21-86) and 78% presented as late stage. The median dose was 55 Gy (range 39-55) in 16 once daily fractions (range 13-21). At 5 and 10 years, respectively, freedom from local recurrence was 56 and 56%, disease-free survival was 45 and 43%, cancer-specific survival was 53 and 51%, and overall survival was 40 and 21%. Cancer-specific survival was significantly worse with late stage as opposed to early stage (P = 0.0026), as was local recurrence (P = 0.0088). No differences in survival and local control were seen according to site. Radionecrosis developed in 6% of patients. Combined treatment using radiotherapy and radical surgery is often favoured. This large series shows that radical radiotherapy achieves comparable results in terms of local control and cancer-specific survival. Our radiotherapy regimen is now 55 Gy in 20 daily fractions to reduce late morbidity. Radiotherapy alone remains a viable option, especially as morbidity can be minimised and target volume delineation optimised using computer planning in the future.

  7. Interspecies nuclear transfer using fibroblasts from leopard, tiger, and lion ear piece collected postmortem as donor cells and rabbit oocytes as recipients.

    Yelisetti, Uma Mahesh; Komjeti, Suman; Katari, Venu Charan; Sisinthy, Shivaji; Brahmasani, Sambasiva Rao


    Skin fibroblast cells were obtained from a small piece of an ear of leopard, lion, and tiger collected postmortem and attempts were made to synchronize the skin fibroblasts at G0/G1 of cell cycle using three different approaches. Efficiency of the approaches was tested following interspecies nuclear transfer with rabbit oocytes as recipient cytoplasm. Fluorescence-activated cell sorting revealed that the proportion of G0/G1 cells increased significantly (P tiger were successfully synchronized and used for the development of blastocysts using rabbit oocytes as recipient cytoplasm.

  8. Sensory feedback, error correction, and remapping in a multiple oscillator model of place cell activity

    Joseph D. Monaco


    Full Text Available Mammals navigate by integrating self-motion signals (‘path integration’ and occasionally fixing on familiar environmental landmarks. The rat hippocampus is a model system of spatial representation in which place cells are thought to integrate both sensory and spatial information from entorhinal cortex. The localized firing fields of hippocampal place cells and entorhinal grid cells demonstrate a phase relationship with the local theta (6–10 Hz rhythm that may be a temporal signature of path integration. However, encoding self-motion in the phase of theta oscillations requires high temporal precision and is susceptible to idiothetic noise, neuronal variability, and a changing environment. We present a model based on oscillatory interference theory, previously studied in the context of grid cells, in which transient temporal synchronization among a pool of path-integrating theta oscillators produces hippocampal-like place fields. We hypothesize that a spatiotemporally extended sensory interaction with external cues modulates feedback to the theta oscillators. We implement a form of this cue-driven feedback and show that it can retrieve fixed points in the phase code of position. A single cue can smoothly reset oscillator phases to correct for both systematic errors and continuous noise in path integration. Further, simulations in which local and global cues are rotated against each other reveal a phase-code mechanism in which conflicting cue arrangements can reproduce experimentally observed distributions of ‘partial remapping’ responses. This abstract model demonstrates that phase-code feedback can provide stability to the temporal coding of position during navigation and may contribute to the context-dependence of hippocampal spatial representations. While the anatomical substrates of these processes have not been fully characterized, our findings suggest several signatures that can be evaluated in future experiments.

  9. Diversity in Fish Auditory Systems: One of the Riddles of Sensory Biology

    Friedrich eLadich


    Full Text Available An astonishing diversity of inner ears and accessory hearing structures (AHS that can enhance hearing has evolved in fishes. Inner ears mainly differ in the size of the otolith end organs, the shape and orientation of the sensory epithelia, and the orientation patterns of ciliary bundles of sensory hair cells. Despite our profound morphological knowledge of inner ear variation, two main questions remain widely unanswered. (i What selective forces and/or constraints led to the evolution of this inner ear diversity? (ii How is the morphological variability linked to hearing abilities? Improved hearing is mainly based on the ability of many fish species to transmit oscillations of swim bladder walls or other gas-filled bladders to the inner ears. Swim bladders may be linked to the inner ears via a chain of ossicles (in otophysans, anterior extensions (e.g. some cichlids, squirrelfishes, or the gas bladders may touch the inner ears directly (labyrinth fishes. Studies on catfishes and cichlids demonstrate that larger swim bladders and more pronounced linkages to the inner ears positively affect both auditory sensitivities and the detectable frequency range, but lack of a connection does not exclude hearing enhancement. This diversity of auditory structures and hearing abilities is one of the main riddles in fish bioacoustics research. Hearing enhancement might have evolved to facilitate intraspecific acoustic communication. A comparison of sound-producing species, however, indicates that acoustic communication is widespread in taxa lacking AHS. Eco-acoustical constraints are a more likely explanation for the diversity in fish hearing sensitivities. Low ambient noise levels may have facilitated the evolution of AHS, enabling fish to detect low-level abiotic noise and sounds from con- and heterospecifics, including predators and prey. Aquatic habitats differ in ambient noise regimes, and preliminary data indicate that hearing sensitivities of fishes

  10. The L1-type cell adhesion molecule Neuroglian is necessary for maintenance of sensory axon advance in the Drosophila embryo

    Martin Veronica


    Full Text Available Abstract Background Cell adhesion molecules have long been implicated in the regulation of axon growth, but the precise cellular roles played by individual cell adhesion molecules and the molecular basis for their action are still not well understood. We have used the sensory system of the Drosophila embryo to shed light on the mechanism by which the L1-type cell adhesion molecule Neuroglian regulates axon growth. Results We have found a highly penetrant sensory axon stalling phenotype in neuroglian mutant embryos. Axons stalled at a variety of positions along their normal trajectory, but most commonly in the periphery some distance along the peripheral nerve. All lateral and dorsal cluster sensory neurons examined, except for the dorsal cluster neuron dbd, showed stalling. Sensory axons were never seen to project along inappropriate pathways in neuroglian mutants and stalled axons showed normal patterns of fasciculation within nerves. The growth cones of stalled axons possessed a simple morphology, similar to their appearance in wild-type embryos when advancing along nerves. Driving expression of the wild-type form of Neuroglian in sensory neurons alone rescued the neuroglian mutant phenotype of both pioneering and follower neurons. A partial rescue was achieved by expressing the Neuroglian extracellular domain. Over/mis-expression of Neuroglian in all neurons, oenocytes or trachea had no apparent effect on sensory axon growth. Conclusion We conclude that Neuroglian is necessary to maintain axon advance along axonal substrates, but is not required for initiation of axon outgrowth, axon fasciculation or recognition of correct growth substrates. Expression of Neuroglian in sensory neurons alone is sufficient to promote axon advance and the intracellular region of the molecule is largely dispensable for this function. It is unlikely, therefore, that Nrg acts as a molecular 'clutch' to couple adhesion of F-actin within the growth cone to the

  11. The sensory histidine kinases TorS and EvgS tend to form clusters in Escherichia coli cells.

    Erik Sommer

    Full Text Available Microorganisms use multiple two-component sensory systems to detect changes in their environment and elicit physiological responses. Despite their wide spread and importance, the intracellular organization of two-component sensory proteins in bacteria remains little investigated. A notable exception is the well-studied clustering of the chemoreceptor-kinase complexes that mediate chemotaxis behaviour. However, these chemosensory complexes differ fundamentally from other systems, both structurally and functionally. Therefore, studying the organization of typical sensory kinases in bacteria is essential for understanding the general role of receptor clustering in bacterial sensory signalling. Here, by studying mYFP-tagged sensory kinases in Escherichia coli, we show that the tagged TorS and EvgS sensors have a clear tendency for self-association and clustering. These sensors clustered even when expressed at a level of a few hundred copies per cell. Moreover, the mYFP-tagged response regulator TorR showed clear TorS-dependent clustering, indicating that untagged TorS sensors also tend to form clusters. We also provide evidence for the functionality of these tagged sensors. Experiments with truncated TorS or EvgS proteins suggested that clustering of EvgS sensors depends on the cytoplasmic part of the protein, whereas clustering of TorS sensors can be potentially mediated by the periplasmic/transmembrane domain. Overall, these findings support the notion that sensor clustering plays a role in bacterial sensory signalling beyond chemotaxis.

  12. 3D Printed Bionic Ears

    Mannoor, Manu S.; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A.; Soboyejo, Winston O.; Verma, Naveen; Gracias, David H.; McAlpine, Michael C.


    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the precise anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. PMID:23635097

  13. 3D printed bionic ears.

    Mannoor, Manu S; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A; Soboyejo, Winston O; Verma, Naveen; Gracias, David H; McAlpine, Michael C


    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing.

  14. Asymmetric cell division in the Drosophila bristle lineage: from the polarization of sensory organ precursor cells to Notch-mediated binary fate decision.

    Schweisguth, François


    Asymmetric cell division (ACD) is a simple and evolutionary conserved process whereby a mother divides to generate two daughter cells with distinct developmental potentials. This process can generate cell fate diversity during development. Fate asymmetry may result from the unequal segregation of molecules and/or organelles between the two daughter cells. Here, I will review how fate asymmetry is regulated in the sensory bristle lineage in Drosophila and focus on the molecular mechanisms underlying ACD of the sensory organ precursor cells (SOPs). For further resources related to this article, please visit the WIREs website. © 2015 The Authors. WIREs Developmental Biology published by Wiley Periodicals, Inc.

  15. The planar cell polarity protein Strabismus promotes Pins anterior localization during asymmetric division of sensory organ precursor cells in Drosophila.

    Bellaïche, Yohanns; Beaudoin-Massiani, Olivia; Stuttem, Isabella; Schweisguth, François


    Cell fate diversity is generated in part by the unequal segregation of cell-fate determinants during asymmetric cell division. In the Drosophila bristle lineage, the sensory organ precursor (pI) cell is polarized along the anteroposterior (AP) axis by Frizzled (Fz) receptor signaling. We show here that Fz localizes at the posterior apical cortex of the pI cell prior to mitosis, whereas Strabismus (Stbm) and Prickle (Pk), which are also required for AP polarization of the pI cell, co-localize at the anterior apical cortex. Thus, asymmetric localization of Fz, Stbm and Pk define two opposite cortical domains prior to mitosis of the pI cell. At mitosis, Stbm forms an anterior crescent that overlaps with the distribution of Partner of Inscuteable (Pins) and Discs-large (Dlg), two components of the anterior Dlg-Pins-Galphai complex that regulates the localization of cell-fate determinants. At prophase, Stbm promotes the anterior localization of Pins. By contrast, Dishevelled (Dsh) acts antagonistically to Stbm by excluding Pins from the posterior cortex. We propose that the Stbm-dependent recruitment of Pins at the anterior cortex of the pI cell is a novel read-out of planar cell polarity.

  16. Study of the betulin enriched birch bark extracts effects on human carcinoma cells and ear inflammation

    Dehelean Cristina A


    Full Text Available Abstract Background Pentacyclic triterpenes, mainly betulin and betulinic acid, are valuable anticancer agents found in the bark of birch tree. This study evaluates birch bark extracts for the active principles composition. Results New improved extraction methods were applied on the bark of Betula pendula in order to reach the maximum content in active principles. Extracts were analyzed by HPLC-MS, Raman, SERS and 13C NMR spectroscopy which revealed a very high yield of betulin (over 90%. Growth inhibiting effects were measured in vitro on four malignant human cell lines: A431 (skin epidermoid carcinoma, A2780 (ovarian carcinoma, HeLa (cervix adenocarcinoma and MCF7 (breast adenocarcinoma, by means of MTT assay. All of the prepared bark extracts exerted a pronounced antiproliferative effect against human cancer cell lines. In vivo studies involved the anti-inflammatory effect of birch extracts on TPA-induced model of inflammation in mice. Conclusions The research revealed the efficacy of the extraction procedures as well as the antiproliferative and anti-inflammatory effects of birch extracts.

  17. Simultaneous detection of both nitric oxide and reactive oxygen species in guinea pig vestibular sensory cells.

    Takumida, Masaya; Anniko, Matti


    Gentamicin-induced production of reactive oxygen species (ROS) and of nitric oxide (NO) in the vestibular end organs of the guinea pig was investigated by applying two new fluorescence indicators, 4,5-diaminofluorescein diacetate for direct detection of NO and dihydrotetramethylrosamine for ROS. The vestibular sensory cells produced both NO and ROS after exposure to gentamicin. A nonspecific inhibitor of NO synthase, L-NAME, inhibited the production of NO but did not appear to affect the production of ROS following exposure to gentamicin. In contrast, a radical scavenger, D-methionine, or the neurotrophin BDNF suppressed the production of ROS, in turn stimulating NO production. These findings could indicate that both NO and ROS play an important role in aminoglycoside ototoxicity. Copyright 2002 S. Karger AG, Basel

  18. Ear Infection and Vaccines

    ... an ENT Doctor Near You Ear Infection and Vaccines Ear Infection and Vaccines Patient Health Information News ... or may need reinsertion over time. What about vaccines? A vaccine is a preparation administered to stimulate ...

  19. Middle Ear Infections

    ... Listen Español Text Size Email Print Share Middle Ear Infections Page Content Article Body What are the ... illness. What if a child with a middle ear infection is in great pain and discomfort? The ...

  20. Ear surgery - slideshow

    ... this page: // Ear surgery - series—Normal anatomy To use the sharing ... Overview This image demonstrates normal appearance of the ears in relation to the face. Review Date 10/ ...

  1. Otoplasty (Cosmetic Ear Surgery)

    ... By Mayo Clinic Staff Otoplasty — also known as cosmetic ear surgery — is a procedure to change the ... Society of Plastic Surgeons. Accessed June 16, 2015. ...

  2. Nanoparticle Mediated Drug Delivery of Rolipram to Tyrosine Kinase B Positive Cells in the Inner Ear with Targeting Peptides and Agonistic Antibodies

    Rudolf eGlueckert


    Full Text Available AimSystemic pharmacotherapies have limitation due to blood-labyrinth barrier, so local delivery via the round window membrane opens a path for effective treatment. Multifunctional nanoparticle (NP mediated cell specific drug delivery may enhance efficacy and reduce side effects. Different NPs with ligands to target TrkB receptor were tested. Distribution, uptake mechanisms, trafficking, and bioefficacy of drug release of rolipram loaded NPs were evaluated.Methods We tested lipid based nanocapsules (LNCs, Quantum Dot, silica NPs with surface modification by peptides mimicking TrkB or TrkB activating antibodies. Bioefficacy of drug release was tested with rolipram loaded LNCs to prevent cisplatin induced apoptosis. We established different cell culture models with SH-SY-5Y and inner ear derived cell lines and used neonatal and adult mouse explants. Uptake and trafficking was evaluated with FACS and confocal as well as transmission electron microscopy. ResultsPlain NPs show some selectivity in uptake related to the in-vitro system properties, carrier material and NP size. Some peptide ligands provide enhanced targeted uptake to neuronal cells but failed to show this in cell cultures. Agonistic antibodies linked to silica NPs showed TrkB activation and enhanced binding to inner ear derived cells. Rolipram loaded LNCs proved as effective carriers to prevent cisplatin induced apoptosis.DiscussionMost NPs with targeting ligands showed limited effects to enhance uptake. NP aggregation and unspecific binding may change uptake mechanisms and impair endocytosis by an overload of NPs. This may affect survival signaling. NPs with antibodies activate survival signaling and show effective binding to TrkB positive cells but needs further optimization for specific internalization. Bioefficiacy of rolipram release confirms LNCs as encouraging vectors for drug delivery of lipophilic agents to the inner ear with ideal release characteristics independent of

  3. Middle Ear Infections (For Parents)

    ... Feeding Your 1- to 2-Year-Old Middle Ear Infections KidsHealth > For Parents > Middle Ear Infections Print ... 3 years old. A Close Look at the Ear To understand how ear infections develop, let's review ...

  4. Diverse expression patterns of LIM-homeodomain transcription factors (LIM-HDs) in mammalian inner ear development.

    Huang, Mingqian; Sage, Cyrille; Li, Huawei; Xiang, Mengquig; Heller, Stefan; Chen, Zheng-Yi


    LIM-homeodomain transcription factors (LIM-HDs) are essential in tissue patterning and differentiation. But their expression patterns in the inner ear are largely unknown. Here we report on a study of twelve LIM-HDs, by their tempo-spatial patterns that imply distinct yet overlapping roles, in the developing mouse inner ear. Expression of Lmx1a and Isl1 begins in the otocyst stage, with Lmx1a exclusively in the non-sensory and Isl1 in the prosensory epithelia. The second wave of expression at E12.5 includes Lhx3, 5, 9, Isl2, and Lmx1b in the differentiating sensory epithelia with cellular specificities. With the exception of Lmx1a and Lhx3, all LIM-HDs are expressed in ganglion neurons. Expression of multiple LIM-HDs within a cell type suggests their redundant function.

  5. Anatomical and physiological development of the human inner ear.

    Lim, Rebecca; Brichta, Alan M


    We describe the development of the human inner ear with the invagination of the otic vesicle at 4 weeks gestation (WG), the growth of the semicircular canals from 5 WG, and the elongation and coiling of the cochlea at 10 WG. As the membranous labyrinth takes shape, there is a concomitant development of the sensory neuroepithelia and their associated structures within. This review details the growth and differentiation of the vestibular and auditory neuroepithelia, including synaptogenesis, the expression of stereocilia and kinocilia, and innervation of hair cells by afferent and efferent nerve fibres. Along with development of essential sensory structures we outline the formation of crucial accessory structures of the vestibular system - the cupula and otolithic membrane and otoconia as well as the three cochlea compartments and the tectorial membrane. Recent molecular studies have elaborated on classical anatomical studies to characterize the development of prosensory and sensory regions of the fetal human cochlea using the transcription factors, PAX2, MAF-B, SOX2, and SOX9. Further advances are being made with recent physiological studies that are beginning to describe when hair cells become functionally active during human gestation. This article is part of a Special Issue entitled Reviews 2016>.

  6. Ear Injuries (For Parents)

    ... head, sports injuries, and even listening to loud music can cause ear damage, which can affect hearing and balance. That's because the ear not ... Hearing Loss or Balance Problems Ear injuries can affect kids differently. ... sounds or music notes hearing only certain or muffled sounds ringing ...

  7. Coupling and elastic loading affect the active response by the inner ear hair cell bundles.

    Clark Elliott Strimbu

    Full Text Available Active hair bundle motility has been proposed to underlie the amplification mechanism in the auditory endorgans of non-mammals and in the vestibular systems of all vertebrates, and to constitute a crucial component of cochlear amplification in mammals. We used semi-intact in vitro preparations of the bullfrog sacculus to study the effects of elastic mechanical loading on both natively coupled and freely oscillating hair bundles. For the latter, we attached glass fibers of different stiffness to the stereocilia and observed the induced changes in the spontaneous bundle movement. When driven with sinusoidal deflections, hair bundles displayed phase-locked response indicative of an Arnold Tongue, with the frequency selectivity highest at low amplitudes and decreasing under stronger stimulation. A striking broadening of the mode-locked response was seen with increasing stiffness of the load, until approximate impedance matching, where the phase-locked response remained flat over the physiological range of frequencies. When the otolithic membrane was left intact atop the preparation, the natural loading of the bundles likewise decreased their frequency selectivity with respect to that observed in freely oscillating bundles. To probe for signatures of the active process under natural loading and coupling conditions, we applied transient mechanical stimuli to the otolithic membrane. Following the pulses, the underlying bundles displayed active movement in the opposite direction, analogous to the twitches observed in individual cells. Tracking features in the otolithic membrane indicated that it moved in phase with the bundles. Hence, synchronous active motility evoked in the system of coupled hair bundles by external input is sufficient to displace large overlying structures.

  8. Establishment and characteristics of a Yunnan pony ear marginal fibroblast cell line%云南矮马耳缘组织成纤维细胞系的建立及其生物学特性

    周向梅; 马月辉; 关伟军; 赵德明


    A Yunnan pony ear marginal tissue fibroblast cell line (NYPEM 2/2) was successfully established using the explant of the ear marginal tissue and then trypsinization the cells from the outgrowth. Observations on cell morphology and dynamic growth, analysis of karyotype and isoenzymes of lactate dehydrogenase and malate dehydrogenase were carried out. The expression of recombinant green fluorescence protein in the cells were also undertaken. The results showed that the population doubling time (PDT) of the cells was 24 h; the frequency of cell chromosome number to be 2n = 64 was 92.9%; the banding patterns of the isozymes of the two enzymes had significant difference between the Yunnan pony ear marginal fibroblast cell line and the fibroblast cell lines of PEM 2/2, MSHEM 2/2 and BLCHE 2/2 derived from the Picdmont bovine ear, Mongolian ovine ear and Beijing local chicken embryo respectively. Tests for the contamination from bacteria, fungi or mycoplasma were negative; the transfection efficiency for the recombinant plasmid was 32.3%. This newly established cell line make the Yunnan pony breed, a national important genetic resource preserved at cell level, as well as will provide an effective experimental material for genetic studies on the Yunnan pony [ Acta Zoologica Sinica 50(5): 863-868, 2004].

  9. Mechanics of the frog ear

    Van Dijk, Pim; Mason, Matthew J.; Schoffelen, Richard L. M.; Narins, Peter M.; Meenderink, Sebastiaan W. F.


    The frog inner ear contains three regions that are sensitive to airborne sound and which are functionally distinct. (1) The responses of nerve fibres innervating the low-frequency, rostral part of the amphibian papilla (AP) are complex. Electrical tuning of hair cells presumably contributes to the f

  10. The role of her4 in inner ear development and its relationship with proneural genes and Notch signalling.

    Marija Radosevic

    Full Text Available The generation of sensory neurons and hair cells of the inner ear is under tight control. Different members of the Hairy and Enhancer of Split genes (HES are expressed in the inner ear, their full array of functions still not being disclosed. We have previously shown that zebrafish her9 acts as a patterning gene to restrict otic neurogenesis to an anterior domain. Here, we disclose the role of another her gene, her4, a zebrafish ortholog of Hes5 that is expressed in the neurogenic and sensory domains of the inner ear. The expression of her4 is highly dynamic and spatiotemporally regulated. We demonstrate by loss of function experiments that in the neurogenic domain her4 expression is under the regulation of neurogenin1 (neurog1 and the Notch pathway. Moreover, her4 participates in lateral inhibition during otic neurogenesis since her4 knockdown results in overproduction of the number of neurog1 and deltaB-positive otic neurons. In contrast, during sensorigenesis her4 is initially Notch-independent and induced by atoh1b in a broad prosensory domain. At later stages her4 expression becomes Notch-dependent in the future sensory domains but loss of her4 does not result in hair cell overproduction, suggesting that there other her genes can compensate its function.

  11. Live-imaging of PKC translocation in Sf9 cells and in aplysia sensory neurons.

    Farah, Carole A; Sossin, Wayne S


    Protein kinase Cs (PKCs) are serine threonine kinases that play a central role in regulating a wide variety of cellular processes such as cell growth and learning and memory. There are four known families of PKC isoforms in vertebrates: classical PKCs (α, βI, βII and γ), novel type I PKCs (ε and η), novel type II PKCs (δ and θ), and atypical PKCs (ζ and ι). The classical PKCs are activated by Ca(2+) and diacylclycerol (DAG), while the novel PKCs are activated by DAG, but are Ca(2+)-independent. The atypical PKCs are activated by neither Ca(2+) nor DAG. In Aplysia californica, our model system to study memory formation, there are three nervous system specific PKC isoforms one from each major class, namely the conventional PKC Apl I, the novel type I PKC Apl II and the atypical PKC Apl III. PKCs are lipid-activated kinases and thus activation of classical and novel PKCs in response to extracellular signals has been frequently correlated with PKC translocation from the cytoplasm to the plasma membrane. Therefore, visualizing PKC translocation in real time in live cells has become an invaluable tool for elucidating the signal transduction pathways that lead to PKC activation. For instance, this technique has allowed for us to establish that different isoforms of PKC translocate under different conditions to mediate distinct types of synaptic plasticity and that serotonin (5HT) activation of PKC Apl II requires production of both DAG and phosphatidic acid (PA) for translocation (1-2). Importantly, the ability to visualize the same neuron repeatedly has allowed us, for example, to measure desensitization of the PKC response in exquisite detail (3). In this video, we demonstrate each step of preparing Sf9 cell cultures, cultures of Aplysia sensory neurons have been described in another video article (4), expressing fluorescently tagged PKCs in Sf9 cells and in Aplysia sensory neurons and live-imaging of PKC translocation in response to different activators using

  12. Postoperative Intensity-Modulated Radiotherapy for Squamous Cell Carcinoma of the External Auditory Canal and Middle Ear: Treatment Outcomes, Marginal Misses, and Perspective on Target Delineation

    Chen, Wan-Yu [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Kuo, Sung-Hsin [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan (China); Chen, Yu-Hsuan; Lu, Szu-Huai; Tsai, Chiao-Ling [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Chia-Hsien Cheng, Jason [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan (China); Graduate Institute of Oncology, National Taiwan University College of Medicine, Taipei, Taiwan (China); Hong, Ruey-Long [Division of Medical Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Chen, Ya-Fang [Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan (China); Hsu, Chuan-Jen; Lin, Kai-Nan; Ko, Jenq-Yuh; Lou, Pei-Jen; Wang, Cheng-Ping [Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan (China); Chong, Fok-Ching [Graduate Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Wang, Chun-Wei, E-mail: [Graduate Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China)


    Purpose: To report outcomes of the rare disease of squamous cell carcinoma (SCC) of the external auditory canal (EAC) and middle ear treated with surgery and postoperative intensity-modulated radiotherapy (IMRT). Failure patterns related to spatial dose distribution were also analyzed to provide insight into target delineation. Methods and Materials: A retrospective review was conducted of the records of 11 consecutive patients with SCC of the EAC and middle ear who were treated with curative surgery and postoperative IMRT at one institution between January 2007 and February 2010. The prescribed IMRT dose was 60 to 66 Gy at 2 Gy per fraction. Three patients also received concurrent cisplatin-based chemotherapy, and 1 patient received concurrent oral tegafur/uracil. The median follow-up time was 19 months (range, 6-33 months). Results: Four patients had locoregional recurrence, yielding an estimated 2-year locoregional control rate of 70.7%. Among them, 1 patient had persistent disease after treatment, and 3 had marginal recurrence. Distant metastasis occurred in 1 patient after extensive locoregional recurrence, yielding an estimated 2-year distant control rate of 85.7%. The estimated 2-year overall survival was 67.5%. The three cases of marginal recurrence were near the preauricular space and glenoid fossa of the temporomandibular joint, adjacent to the apex of the ear canal and glenoid fossa of the temporomandibular joint, and in the postauricular subcutaneous area and ipsilateral parotid nodes, respectively. Conclusions: Marginal misses should be recognized to improve target delineation. When treating SCC of the EAC and middle ear, care should be taken to cover the glenoid fossa of the temporomandibular joint and periauricular soft tissue. Elective ipsilateral parotid irradiation should be considered. The treatment planning procedure should also be refined to balance subcutaneous soft-tissue dosimetry and toxicity.

  13. Pox neuro control of cell lineages that give rise to larval poly-innervated external sensory organs in Drosophila.

    Jiang, Yanrui; Boll, Werner; Noll, Markus


    The Pox neuro (Poxn) gene of Drosophila plays a crucial role in the development of poly-innervated external sensory (p-es) organs. However, how Poxn exerts this role has remained elusive. In this study, we have analyzed the cell lineages of all larval p-es organs, namely of the kölbchen, papilla 6, and hair 3. Surprisingly, these lineages are distinct from any previously reported cell lineages of sensory organs. Unlike the well-established lineage of mono-innervated external sensory (m-es) organs and a previously proposed model of the p-es lineage, we demonstrate that all wild-type p-es lineages exhibit the following features: the secondary precursor, pIIa, gives rise to all three support cells-socket, shaft, and sheath, whereas the other secondary precursor, pIIb, is neuronal and gives rise to all neurons. We further show that in one of the p-es lineages, that of papilla 6, one cell undergoes apoptosis. By contrast in Poxn null mutants, all p-es lineages have a reduced number of cells and their pattern of cell divisions is changed to that of an m-es organ, with the exception of a lineage in a minority of mutant kölbchen that retains a second bipolar neuron. Indeed, the role of Poxn in p-es lineages is consistent with the specification of the developmental potential of secondary precursors and the regulation of cell division but not apoptosis.

  14. Olfactory sensory deprivation increases the number of proBDNF-immunoreactive mitral cells in the olfactory bulb of mice.

    Biju, K C; Mast, Thomas Gerald; Fadool, Debra Ann


    In the olfactory bulb, apoptotic cell-death induced by sensory deprivation is restricted to interneurons in the glomerular and granule cell layers, and to a lesser extent in the external plexiform layer, whereas mitral cells do not typically undergo apoptosis. With the goal to understand whether brain-derived neurotrophic factor (BDNF) mediates mitral cell survival, we performed unilateral naris occlusion on mice at postnatal day one (P1) and examined the subsequent BDNF-immunoreactive (BDNF-ir) profile of the olfactory bulb at P20, P30, and P40. Ipsilateral to the naris occlusion, there was a significant increase in the number of BDNF-ir mitral cells per unit area that was independent of the duration of the sensory deprivation induced by occlusion. The number of BDNF-ir juxtaglomerular cells per unit area, however, was clearly diminished. Western blot analysis revealed the presence of primarily proBDNF in the olfactory bulb. These data provide evidence for a neurotrophic role of proBDNF in the olfactory system of mice and suggest that proBDNF may act to protect mitral cells from the effects of apoptotic changes induced by odor sensory deprivation.

  15. The core planar cell polarity gene prickle interacts with flamingo to promote sensory axon advance in the Drosophila embryo.

    Mrkusich, Eli M; Flanagan, Dustin J; Whitington, Paul M


    The atypical cadherin Drosophila protein Flamingo and its vertebrate homologues play widespread roles in the regulation of both dendrite and axon growth. However, little is understood about the molecular mechanisms that underpin these functions. Whereas flamingo interacts with a well-defined group of genes in regulating planar cell polarity, previous studies have uncovered little evidence that the other core planar cell polarity genes are involved in regulation of neurite growth. We present data in this study showing that the planar cell polarity gene prickle interacts with flamingo in regulating sensory axon advance at a key choice point - the transition between the peripheral nervous system and the central nervous system. The cytoplasmic tail of the Flamingo protein is not required for this interaction. Overexpression of another core planar cell polarity gene dishevelled produces a similar phenotype to prickle mutants, suggesting that this gene may also play a role in regulation of sensory axon advance.

  16. Aquaporin 4 in the sensory organs of adult zebrafish (Danio rerio).

    Zichichi, Rosalia; Magnoli, Domenico; Montalbano, Giuseppe; Laurà, Rosaria; Vega, José A; Ciriaco, Emilia; Germanà, Antonino


    The aquaporins (AQPs) are a family (AQP-AQP10) of transmembrane channel proteins that mediate the transport of water, ions, gases, and small molecules across the cell membrane, thus regulating cell homeostasis. AQP4 has the highest water permeability and it is involved in hearing and vision in mammals. Here, we used immunohistochemistry to map the presence of AQP4 in the sensory organs of adult zebrafish. The antibody used detected by Western blot proteins of 34 kDa (equivalent to that of mammalian AQP4) and maps in the sensory cells of taste buds, the hair sensory cells of the neuromast and of the maculae, and cristae ampullaris of the inner ear. Moreover, the retinal photoreceptors display AQP4 immunoreactivity. The non-sensory cells in these organs were AQP4 negative. These results suggest that the AQP4 could play a role in the regulation of water balance and ion transport in the sensory cells of zebrafish, bringing new data for the utilizing of this experimental model in the biology of sensory system.

  17. Development of gene therapy for inner ear disease: Using bilateral vestibular hypofunction as a vehicle for translational research.

    Staecker, Hinrich; Praetorius, Mark; Brough, Douglas E


    Despite the significant impact of hearing and balance disorders on the general population there are currently no dedicated pharmaceuticals that target the inner ear. Advances in molecular biology and neuroscience have improved our understanding of the inner ear allowing the development of a range of molecular targets that have the potential to treat both hearing and balance disorders. One of the principal advantages of the inner ear is that it is accessible through a variety of approaches that would allow a potential to be delivered locally rather than systemically. This significantly broadens the potential medications that can be developed and opens the possibility of local gene delivery as a therapeutic intervention. Several potential clinical targets have been identified including delivery of neurotrophin expressing genes as an adjunct to cochlear implantation, delivery of protective genes to prevent trauma and the development of strategies for regenerating inner ear sensory cells. In order to translate these potential therapeutics into humans we will want to optimize the gene delivery methodology, dosing and activity of the drug for therapeutic value. To this end we have developed a series of adenovectors that efficiently transduce the inner ear. The use of these gene delivery approaches are attractive for the potential of hair cell regeneration after loss induced by trauma or ototoxins. This approach is particularly suited for the development of molecular therapies targeted at the vestibular system given that no device based therapeutic such a cochlear implant available for vestibular loss.

  18. L-Amino Acids Elicit Diverse Response Patterns in Taste Sensory Cells: A Role for Multiple Receptors.

    Shreoshi Pal Choudhuri

    Full Text Available Umami, the fifth basic taste, is elicited by the L-amino acid, glutamate. A unique characteristic of umami taste is the response potentiation by 5' ribonucleotide monophosphates, which are also capable of eliciting an umami taste. Initial reports using human embryonic kidney (HEK cells suggested that there is one broadly tuned receptor heterodimer, T1r1+T1r3, which detects L-glutamate and all other L-amino acids. However, there is growing evidence that multiple receptors detect glutamate in the oral cavity. While much is understood about glutamate transduction, the mechanisms for detecting the tastes of other L-amino acids are less well understood. We used calcium imaging of isolated taste sensory cells and taste cell clusters from the circumvallate and foliate papillae of C57BL/6J and T1r3 knockout mice to determine if other receptors might also be involved in detection of L-amino acids. Ratiometric imaging with Fura-2 was used to study calcium responses to monopotassium L-glutamate, L-serine, L-arginine, and L-glutamine, with and without inosine 5' monophosphate (IMP. The results of these experiments showed that the response patterns elicited by L-amino acids varied significantly across taste sensory cells. L-amino acids other than glutamate also elicited synergistic responses in a subset of taste sensory cells. Along with its role in synergism, IMP alone elicited a response in a large number of taste sensory cells. Our data indicate that synergistic and non-synergistic responses to L-amino acids and IMP are mediated by multiple receptors or possibly a receptor complex.

  19. Acoustics of the human middle-ear air space.

    Stepp, Cara E; Voss, Susan E


    The impedance of the middle-ear air space was measured on three human cadaver ears with complete mastoid air-cell systems. Below 500 Hz, the impedance is approximately compliance-like, and at higher frequencies (500-6000 Hz) the impedance magnitude has several (five to nine) extrema. Mechanisms for these extrema are identified and described through circuit models of the middle-ear air space. The measurements demonstrate that the middle-ear air space impedance can affect the middle-ear impedance at the tympanic membrane by as much as 10 dB at frequencies greater than 1000 Hz. Thus, variations in the middle-ear air space impedance that result from variations in anatomy of the middle-ear air space can contribute to inter-ear variations in both impedance measurements and otoacoustic emissions, when measured at the tympanic membrane.

  20. Regional differences in sensory innervation and suburothelial interstitial cells in the bladder neck and urethra.

    Grol, Simone; van Koeveringe, Gommert A; de Vente, Jan; van Kerrebroeck, Philip E V; Gillespie, James I


    To identify and characterize possible structural specialisations in the wall of the lower urinary tract (LUT) in the region of the bladder urethral junction (BUJ), with the specific objective of identifying regional variations in sensory nerve fibres and interstitial cells (ICs). The bladder base and urethra was removed from five male guinea pigs killed by cervical dislocation. Tissue pieces were incubated in Krebs' solution at 36 degrees C, gassed with 95% O(2) and 5% CO(2), fixed in 4% paraformaldehyde and processed for immunohistochemistry. The nonspecific marker vimentin and the general neuronal marker protein gene product (PGP) 9.5 were used to identify ICs and nerve fibres, respectively. Specific antibody binding was visualized using the appropriate secondary antibodies. The wall of the LUT in the region immediately between the bladder base and the urethra, the BUJ, differed in its cellular composition relative to the adjacent areas. PGP-positive (PGP(+)) nerve fibres, presumptive afferent fibres, lay within the urothelium running between the epithelial cells. There were two general nerve patterns: branching fibres with no varicosities, and complex fibres with varicosities. Fibre collaterals with varicosities exited the urothelium and occupied the space under the urothelium adjacent to the layer of suburothelial ICs. The latter, lamina propria and around the muscle bundles were identified using vimentin (vim(+)). In the base a few vim(+) cells were also PGP(+). In the region of the BUJ there was a decrease in the amount of smooth muscle. In this region, below the lamina propria, there was an area densely populated with vim(+)/PGP(+) ICs. Nerve fibres ran between the cells in this region. These structural specialisations within the urothelium and deeper layers of the BUJ suggest that they might be associated with specific functions. The localized highly branched network of the putative afferent nerves suggests the presence of a local axonal reflexes involving

  1. Does the morphology of the ear of the Chinese bamboo rat (Rhizomys sinensis) show "Subterranean" characteristics?

    Pleštilová, Lucie; Hrouzková, Ema; Burda, Hynek; Šumbera, Radim


    In spite of the growing interest in rodents with subterranean activity in general and the spalacids (Spalacidae) in particular, little is known about the biology of most members of this clade, such as the Chinese bamboo rat (Rhizomys sinensis). Here, we analyzed the ear morphology of R. sinensis with respect to hearing specialization for subterranean or aboveground modes of communication. It is well-known that ecology and style of life of a particular species can be reflected in morphology of its ear, its hearing and vocalization, so we expect that such information could provide us insight into its style of life and its sensory environment. The ratio between the eardrum and stapedial footplate areas, which influences the efficiency of middle ear sound transmission, suggests low hearing sensitivity, as is typical for subterranean species. The cochlea had 3.25 coils and resembled species with good low frequency hearing typical for subterranean mammals. The length of the basilar membrane was 18.9 ± 0.8 mm and its width slowly increased towards the cochlear apex from 60 to 85 μm. The mean density of outer hair cells was 344 ± 22 and of inner hair cells 114 ± 7.3 per 1 mm length of the organ of Corti, and increased apically. These values (except for relatively low hair cell density) usually characterize ears specialized for low frequency hearing. There was no evidence for an acoustic fovea. Apart of low hair cell density which is common in aboveground animals, this species has also relatively large auricles, suggesting the importance of sound localization during surface activity. The ear of the Chinese bamboo rat thus contains features typical for both aboveground and subterranean mammals and suggests that this spalacid has fossorial habits combined with regular aboveground activity.

  2. Modulatory role of sensory innervation on hair follicle stem cell progeny during wound healing of the rat skin.

    Eduardo Martínez-Martínez

    Full Text Available BACKGROUND: The bulge region of the hair follicle contains resident epithelial stem cells (SCs that are activated and mobilized during hair growth and after epidermal wounding. However, little is known about the signals that modulate these processes. Clinical and experimental observations show that a reduced supply of sensory innervation is associated with delayed wound healing. Since axon terminals of sensory neurons are among the components of the bulge SC niche, we investigated whether these neurons are involved in the activation and mobilization of the hair stem cells during wound healing. METHODOLOGY/PRINCIPAL FINDINGS: We used neonatal capsaicin treatment to reduce sensory terminals in the rat skin and performed morphometric analyses using design-based stereological methods. Epithelial proliferation was analyzed by quantifying the number of bromodeoxyuridine-labeled (BrdU(+ nuclei in the epidermis and hair follicles. After wounding, the epidermis of capsaicin-treated rats presented fewer BrdU(+ nuclei than in control rats. To assess SC progeny migration, we employed a double labeling protocol with iododeoxyuridine and chlorodeoxyuridine (IdU(+/CldU(+. The proportion of double-labeled cells was similar in the hair follicles of both groups at 32 h postwounding. IdU(+/CldU(+ cell proportion increased in the epidermis of control rats and decreased in treated rats at 61 h postwounding. The epidermal volume immunostained for keratin 6 was greater in treated rats at 61 h. Confocal microscopy analysis revealed that substance P (SP and calcitonin gene-related peptide (CGRP receptor immunoreactivity were both present in CD34(+ and BrdU-retaining cells of the hair follicles. CONCLUSIONS/SIGNIFICANCE: Our results suggest that capsaicin denervation impairs SC progeny egress from the hair follicles, a circumstance associated with a greater epidermal activation. Altogether, these phenomena would explain the longer times for healing in denervated skin

  3. [Lop ear - knife, tape, or nothing at all?].

    Klockars, Tuomas


    More than 200 different surgical techniques of correction of lop ear have been published. The operation is usually recommended to be performed at the age of six years or after. In addition, lop ear surgery involves risks, the most common complications being bleeding, infections, sensory alterations and scarring problems. Surgical preference and decision should always be based on realistic expectations of the patient or the parents, and prior to the decision they should have adequate information about the nature of the procedure and potential complications. Splint therapy of lop ear is possible for infants.

  4. Serum-free medium supplemented with high-concentration FGF2 for cell expansion culture of human ear chondrocytes promotes redifferentiation capacity.

    Mandl, Erik W; van der Veen, Simone W; Verhaar, Jan A N; van Osch, Gerjo J V M


    For tissue engineering of autologous cartilage, cell expansion is needed to obtain the cell numbers required. Standard expansion media contain bovine serum. This has several disadvantages, that is, the risk of transmitting diseases and serum-batch variations. The aim of this study was to find a serum-free medium with at least the same potential to expand cell numbers as serum-containing media. Ear chondrocytes of three young children were expanded in either serum-containing medium (SCM; DMEM with 10% fetal calf serum) or serum-free medium (SFM; DMEM with ITS+) supplemented with 5 or 100 ng/mL fibroblast growth factor-2 (FGF2). To promote cell adherence onto the culture flask, the serum-free conditions were cultured with 10% serum for 1 day after each trypsinization. After the fourth passage, the chondrocytes were encapsuled in alginate beads and redifferentiated in a SFM (DMEM with ITS+, hydrocortisone, and L-ascorbic acid) supplemented with 10 ng/mL IGF-I and 10 ng/mL TGFbeta-2. Results showed that expansion in SFM with 100 ng/mL FGF2 was comparable to expansion in SCM. Redifferentiation with SFM with IGF-I and TGFbeta-2 showed high collagen type II expression and high GAG/DNA production regardless of which expansion medium had been used. However, chondrocytes expanded in SFM with 100 ng/mL FGF2 resulted in less positive cells for collagen type I and 11-fibrau (a fibroblast membrane marker). The present study shows that it is possible to use serum-free medium for tissue engineering of cartilage. Expansion of immature ear chondrocytes in SFM supplemented with high-concentration FGF2 resulted in high cell numbers, which in addition had better redifferentiation capacity than cells expanded in medium with 10% serum.

  5. Planar Cell Polarity Breaks the Symmetry of PAR Protein Distribution prior to Mitosis in Drosophila Sensory Organ Precursor Cells.

    Besson, Charlotte; Bernard, Fred; Corson, Francis; Rouault, Hervé; Reynaud, Elodie; Keder, Alyona; Mazouni, Khalil; Schweisguth, François


    During development, cell-fate diversity can result from the unequal segregation of fate determinants at mitosis. Polarization of the mother cell is essential for asymmetric cell division (ACD). It often involves the formation of a cortical domain containing the PAR complex proteins Par3, Par6, and atypical protein kinase C (aPKC). In the fly notum, sensory organ precursor cells (SOPs) divide asymmetrically within the plane of the epithelium and along the body axis to generate two distinct cells. Fate asymmetry depends on the asymmetric localization of the PAR complex. In the absence of planar cell polarity (PCP), SOPs divide with a random planar orientation but still asymmetrically, showing that PCP is dispensable for PAR asymmetry at mitosis. To study when and how the PAR complex localizes asymmetrically, we have used a quantitative imaging approach to measure the planar polarization of the proteins Bazooka (Baz, fly Par3), Par6, and aPKC in living pupae. By using imaging of functional GFP-tagged proteins with image processing and computational modeling, we find that Baz, Par6, and aPKC become planar polarized prior to mitosis in a manner independent of the AuroraA kinase and that PCP is required for the planar polarization of Baz, Par6, and aPKC during interphase. This indicates that a "mitosis rescue" mechanism establishes asymmetry at mitosis in PCP mutants. This study therefore identifies PCP as the initial symmetry-breaking signal for the planar polarization of PAR proteins in asymmetrically dividing SOPs.

  6. Replacement of lateral line sensory organs during tail regeneration in salamanders: identification of progenitor cells and analysis of leukocyte activity.

    Jones, J E; Corwin, J T


    It has been proposed that supporting cells may be the progenitors of regenerated hair cells that contribute to recovery of hearing in birds, but regeneration is difficult to visualize in the ear, because it occurs deep in the skull. Hair cells and supporting cells that are comparable to those in the ear are present in lateral line neuromasts, and in axolotl salamanders these cells are accessible to microscopic observation in vivo. After amputation of a segment of the tail that contains neuromasts, cells from the posteriormost neuromast on the tail stump divide rapidly and form a migratory regenerative placode. The cells of the regenerative placode represent a lineage that eventually produces both hair cells and supporting cells in replacement neuromasts. We sought to identify the progenitors of the regenerative placode by using differential interference contrast microscopy combined with time-lapse video recording in living axolotl salamanders. In response to amputation, the mantle-type supporting cells at the posteroventral edge of the neuromast that is nearest to the wound increased their frequency of cell division, and gave rise to the first cells of the placode. The increase in mitotic activity of mantle-type supporting cells was accompanied by an unexplained decrease in the frequency of divisions in the same neuromast's population of internal supporting cells. The time-lapse records suggested that the changes in the mitotic activity of supporting cells might have been linked to the presence of phagocytic leukocytes in the vicinity of the neuromast that was nearest to the wound. Leukocytes were evenly distributed around control neuromasts, but during regeneration leukocyte activity increased significantly in the vicinity of the posterior half of the posteriormost neuromast. The redistribution of leukocytes occurred early in the regenerative response, but a causal role for the leukocytes has not been conclusively established. It is possible that the leukocytes

  7. Accumulation of Regulatory T Cells and Chronic Inflammation in the Middle Ear in a Mouse Model of Chronic Otitis Media with Effusion Induced by Combined Eustachian Tube Blockage and Nontypeable Haemophilus influenzae Infection.

    Hirano, Takashi; Kodama, Satoru; Kawano, Toshiaki; Suzuki, Masashi


    Nontypeable Haemophilus influenzae (NTHi) is associated with chronic otitis media (COM). In this study, we generated a murine model of COM by using eustachian tube (ET) obstruction and NTHi (10(7) CFU) inoculation into the tympanic bulla, and we investigated the relationship between regulatory T cells (Treg) and chronic inflammation in the middle ear. Middle ear effusions (MEEs) and middle ear mucosae (MEM) were collected at days 3 and 14 and at 1 and 2 months after inoculation. Untreated mice served as controls. MEEs were used for bacterial counts and to measure the concentrations of cytokines. MEM were collected for histological evaluation and flow cytometric analysis. Inflammation of the MEM was prolonged throughout this study, and the incidence of NTHi culture-positive MEE was 38% at 2 months after inoculation. The levels of interleukin-1β (IL-β), tumor necrosis factor alpha, IL-10, and transforming growth factor β were increased in the middle ear for up to 2 months after inoculation. CD4(+) CD25(+) FoxP3(+) Treg accumulated in the middle ear, and the percentage of Treg in the MEM increased for up to 2 months after inoculation. Treg depletion induced a 99.9% reduction of bacterial counts in MEEs and also significantly reduced the ratio of NTHi culture-positive MEE. The levels of these cytokines were also reduced in MEEs. In summary, we developed a murine model of COM, and our findings indicate that Treg confer infectious tolerance to NTHi in the middle ear.

  8. Travel Inside the Ear

    Full Text Available ... Search form Search A–Z Index Español Menu Home Health Info Hearing, Ear Infections, and Deafness Balance ... Committees Contact Us Get Involved You are here Home » Health Info » Hearing, Ear Infections, and Deafness Travel ...

  9. Expression patterns of members of the isocitrate dehydrogenase gene family in murine inner ear.

    Kim, Y-R; Kim, K-H; Lee, S; Oh, S-K; Park, J-W; Lee, K-Y; Baek, J-I; Kim, U-K


    Age-related hearing loss (ARHL) is characterized by an age-dependent decline of auditory function characterized by with loss of sensory hair cells, spiral ganglion neurons, and stria vascularis (SV) cells in the cochlea of the inner ear. Aging and age-related diseases result from accumulated oxidative damage caused by reactive oxygen species (ROS) generated by mitochondria. The isocitrate dehydrogenase (IDH) family includes three enzymes in human cells: IDH1, IDH2, and IDH3. Although all three enzymes catalyze the same enzymatic reaction, that is, oxidative decarboxylation of isocitrate to produce α-ketoglutarate, each IDH enzyme has unique features. We identified and characterized IDH expression in the cochlea and vestibule of the murine inner ear. We examined the mRNA expression levels of Idh family members in the cochlea and vestibule using reverse transcription-PCR (RT-PCR) and detected expression of IDH family members in both tissues. We also used immunohistochemistry to localize IDH family members within the cochlea and vestibule of the adult mouse inner ear. IDH1 was detected throughout the cochlea. IDH2 was expressed specifically in the hair cells, spiral ganglion, and stria vascularis. IDH3α was found in the cell bodies of neurons of the spiral ganglion, the stria vascularis, and in types II, IV, and V cells of the spiral ligament in a pattern that resembled the location of the Na(+), K(+)-ATPase ion channel. We postulate that the IDH family participates in transporting K(+) ions in the cochlea. In the vestibule, all IDH family members were detected in both hair cells and the vestibular ganglion. We hypothesize that IDH1, IDH2, and IDH3 function to protect proteins in the inner ear from oxidative stress during K(+) recycling.

  10. "Swimmer's Ear" (Otitis Externa) Prevention

    ... infections, swimmer’s ear, and healthy swimming. "Swimmer's Ear" (Otitis Externa) What are the symptoms of swimmer's ear? ... Healthy page. Reference CDC. Estimated burden of acute otitis externa —United States, 2003–2007 . MMWR Morb Mortal ...

  11. Ear - blocked at high altitudes

    High altitudes and blocked ears; Flying and blocked ears; Eustachian tube dysfunction - high altitude ... eustachian tube is a connection between the middle ear (the space deep to the eardrum) and the ...

  12. The preplacodal region: an ectodermal domain with multipotential progenitors that contribute to sense organs and cranial sensory ganglia.

    Streit, Andrea


    The otic primordium belongs to a group of related structures, the sensory placodes that contribute to the paired sense organs - ear, eye and olfactory epithelium - and to the distal parts of the cranial sensory ganglia. Recent evidence suggests that despite their diversity, all placodes share a common developmental origin and a common molecular mechanism which initiates their formation. At the base of placode induction lies the specification of a unique "placode field", termed the preplacodal region and acquisition of this "preplacodal state" is required for ectodermal cells to undergo otic development. Here I review the molecular mechanisms that sequentially subdivide the ectoderm to give rise to the placode territory.

  13. Structural and Functional Substitution of Deleted Primary Sensory Neurons by New Growth from Intrinsic Spinal Cord Nerve Cells: An Alternative Concept in Reconstruction of Spinal Cord Circuits

    Nicholas D. James


    Full Text Available In a recent clinical report, return of the tendon stretch reflex was demonstrated after spinal cord surgery in a case of total traumatic brachial plexus avulsion injury. Peripheral nerve grafts had been implanted into the spinal cord to reconnect to the peripheral nerves for motor and sensory function. The dorsal root ganglia (DRG containing the primary sensory nerve cells had been surgically removed in order for secondary or spinal cord sensory neurons to extend into the periphery and replace the deleted DRG neurons. The present experimental study uses a rat injury model first to corroborate the clinical finding of a re-established spinal reflex arch, and second, to elucidate some of the potential mechanisms underlying these findings by means of morphological, immunohistochemical, and electrophysiological assessments. Our findings indicate that, after spinal cord surgery, the central nervous system sensory system could replace the traumatically detached original peripheral sensory connections through new neurite growth from dendrites.

  14. Human Induced Pluripotent Cell-Derived Sensory Neurons for Fate Commitment of Bone Marrow-Derived Schwann Cells: Implications for Remyelination Therapy.

    Cai, Sa; Han, Lei; Ao, Qiang; Chan, Ying-Shing; Shum, Daisy Kwok-Yan


    : Strategies that exploit induced pluripotent stem cells (iPSCs) to derive neurons have relied on cocktails of cytokines and growth factors to bias cell-signaling events in the course of fate choice. These are often costly and inefficient, involving multiple steps. In this study, we took an alternative approach and selected 5 small-molecule inhibitors of key signaling pathways in an 8-day program to induce differentiation of human iPSCs into sensory neurons, reaching ≥80% yield in terms of marker proteins. Continuing culture in maintenance medium resulted in neuronal networks immunopositive for synaptic vesicle markers and vesicular glutamate transporters suggestive of excitatory neurotransmission. Subpopulations of the derived neurons were electrically excitable, showing tetrodotoxin-sensitive action potentials in patch-clamp experiments. Coculture of the derived neurons with rat Schwann cells under myelinating conditions resulted in upregulated levels of neuronal neuregulin 1 type III in conjunction with the phosphorylated receptors ErbB2 and ErbB3, consistent with amenability of the neuritic network to myelination. As surrogates of embryonic dorsal root ganglia neurons, the derived sensory neurons provided contact-dependent cues to commit bone marrow-derived Schwann cell-like cells to the Schwann cell fate. Our rapid and efficient induction protocol promises not only controlled differentiation of human iPSCs into sensory neurons, but also utility in the translation to a protocol whereby human bone marrow-derived Schwann cells become available for autologous transplantation and remyelination therapy.

  15. BODIPY-Conjugated Xyloside Primes Fluorescent Glycosaminoglycans in the Inner Ear of Opsanus tau.

    Holman, Holly A; Tran, Vy M; Kalita, Mausam; Nguyen, Lynn N; Arungundram, Sailaja; Kuberan, Balagurunathan; Rabbitt, Richard D


    We report on a new xyloside conjugated to BODIPY, BX and its utility to prime fluorescent glycosaminoglycans (BX-GAGs) within the inner ear in vivo. When BX is administered directly into the endolymphatic space of the oyster toadfish (Opsanus tau) inner ear, fluorescent BX-GAGs are primed and become visible in the sensory epithelia of the semicircular canals, utricle, and saccule. Confocal and 2-photon microscopy of vestibular organs fixed 4 h following BX treatment, reveal BX-GAGs constituting glycocalyces that envelop hair cell kinocilium, nerve fibers, and capillaries. In the presence of GAG-specific enzymes, the BX-GAG signals are diminished, suggesting that chondroitin sulfates are the primary GAGs primed by BX. Results are consistent with similar click-xylosides in CHO cell lines, where the xyloside enters the Golgi and preferentially initiates chondroitin sulfate B production. Introduction of BX produces a temporary block of hair cell mechanoelectrical transduction (MET) currents in the crista, reduction in background discharge rate of afferent neurons, and a reduction in sensitivity to physiological stimulation. A six-degree-of-freedom pharmacokinetic mathematical model has been applied to interpret the time course and spatial distribution of BX and BX-GAGs. Results demonstrate a new optical approach to study GAG biology in the inner ear, for tracking synthesis and localization in real time.

  16. Current strategies for drug delivery to the inner ear

    Hongzhuo Liu


    Full Text Available For many years, drug delivery to the inner ear has been a challenge to physicians in the treatment of inner ear disorders. In the past decade, the field of inner ear drug delivery has emerged with the development of new biomaterials and drug delivery technologies to improve the effectiveness of inner ear drug therapy. This paper reviews a number of inner ear drug delivery strategies including systemic, intratympanic, and intracochlear delivery. A focus of this review is the recent advances in intratympanic delivery of medications; approaches utilizing novel biomaterials as well as other recent developments are also discussed. Biotechnology-based approaches, such as gene and stem cell therapy methods are also reviewed. Among the various strategies, local drug delivery approaches including intratympanic and intracochlear drug delivery methods that limit systemic exposure are particularly promising. These inner ear drug delivery systems provide a new opportunity to improve the treatment of inner ear disorders.

  17. Ear Problems in Swimmers

    Mao-Che Wang


    Full Text Available Acute diffuse otitis externa (swimmer's ear, otomycosis, exostoses, traumatic eardrum perforation, middle ear infection, and barotraumas of the inner ear are common problems in swimmers and people engaged in aqua activities. The most common ear problem in swimmers is acute diffuse otitis externa, with Pseudomonas aeruginosa being the most common pathogen. The symptoms are itching, otalgia, otorrhea, and conductive hearing loss. The treatment includes frequent cleansing of the ear canal, pain control, oral or topical medications, acidification of the ear canal, and control of predisposing factors. Swimming in polluted waters and ear-canal cleaning with cotton-tip applicators should be avoided. Exostoses are usually seen in people who swim in cold water and present with symptoms of accumulated debris, otorrhea and conductive hearing loss. The treatment for exostoses is transmeatal surgical removal of the tumors. Traumatic eardrum perforations may occur during water skiing or scuba diving and present with symptoms of hearing loss, otalgia, otorrhea, tinnitus and vertigo. Tympanoplasty might be needed if the perforations do not heal spontaneously. Patients with chronic otitis media with active drainage should avoid swimming, while patients who have undergone mastoidectomy and who have no cavity problems may swim. For children with ventilation tubes, surface swimming is safe in a clean, chlorinated swimming pool. Sudden sensorineural hearing loss and some degree of vertigo may occur after diving because of rupture of the round or oval window membrane.

  18. Ear problems in swimmers.

    Wang, Mao-Che; Liu, Chia-Yu; Shiao, An-Suey; Wang, Tyrone


    Acute diffuse otitis externa (swimmer's ear), otomycosis, exostoses, traumatic eardrum perforation, middle ear infection, and barotraumas of the inner ear are common problems in swimmers and people engaged in aqua activities. The most common ear problem in swimmers is acute diffuse otitis externa, with Pseudomonas aeruginosa being the most common pathogen. The symptoms are itching, otalgia, otorrhea, and conductive hearing loss. The treatment includes frequent cleansing of the ear canal, pain control, oral or topical medications, acidification of the ear canal, and control of predisposing factors. Swimming in polluted waters and ear-canal cleaning with cotton-tip applicators should be avoided. Exostoses are usually seen in people who swim in cold water and present with symptoms of accumulated debris, otorrhea and conductive hearing loss. The treatment for exostoses is transmeatal surgical removal of the tumors. Traumatic eardrum perforations may occur during water skiing or scuba diving and present with symptoms of hearing loss, otalgia, otorrhea, tinnitus and vertigo. Tympanoplasty might be needed if the perforations do not heal spontaneously. Patients with chronic otitis media with active drainage should avoid swimming, while patients who have undergone mastoidectomy and who have no cavity problems may swim. For children with ventilation tubes, surface swimming is safe in a clean, chlorinated swimming pool. Sudden sensorineural hearing loss and some degree of vertigo may occur after diving because of rupture of the round or oval window membrane.

  19. Gravity and the cells of gravity receptors in mammals

    Ross, M. D.

    Two new findings, that crystals located in the inner ear gravity receptors of mammals have the internal organization requisite for the piezoelectric property, and that sensory hair cells of these same receptors possess contractile-appearing striated organelles, have prompted the author to model mammalian gravity receptors in the ear on the principles of piezoelectricity and bioenergetics. This model is presented and a brief discussion of its implications for the possible effects of weightlessness follows.

  20. Nociceptive Sensory Fibers Drive Interleukin-23 Production from CD301b+ Dermal Dendritic Cells and Drive Protective Cutaneous Immunity.

    Kashem, Sakeen W; Riedl, Maureen S; Yao, Chen; Honda, Christopher N; Vulchanova, Lucy; Kaplan, Daniel H


    Innate resistance to Candida albicans in mucosal tissues requires the production of interleukin-17A (IL-17A) by tissue-resident cells early during infection, but the mechanism of cytokine production has not been precisely defined. In the skin, we found that dermal γδ T cells were the dominant source of IL-17A during C. albicans infection and were required for pathogen resistance. Induction of IL-17A from dermal γδ T cells and resistance to C. albicans required IL-23 production from CD301b(+) dermal dendritic cells (dDCs). In addition, we found that sensory neurons were directly activated by C. albicans. Ablation of sensory neurons increased susceptibility to C. albicans infection, which could be rescued by exogenous addition of the neuropeptide CGRP. These data define a model in which nociceptive pathways in the skin drive production of IL-23 by CD301b(+) dDCs resulting in IL-17A production from γδ T cells and resistance to cutaneous candidiasis. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Inner Time and Inner Ear

    Rvachov, Michael


    Sounds are information sequences that cannot exist outside of a time base and therefore cannot be analyzed inside an animal without an accurate internal clock. It is suggested that the clock may be hidden in the inner ear. It is shown that if a mechanism of counting of the electrical charge passing through the inner ear hair cells exists then the mechanism can be used both for the conversion of acceleration into velocity and as the inner clock, in the presence of a constant current. The causes of vertigo during rotation are discussed. It is shown that if a continuous inner time exists then sleeping is a mathematical necessity. It is indicated that both for visual and hearing inputs the recognition of an input signal is recognition of function(s) of two variables.

  2. Swimmer's Ear (For Parents)

    ... Child What Kids Say About: Handling Stress Anxiety, Fears, and Phobias Community Service: A Family's Guide to ... can drain into the ear canal through a hole in the eardrum and cause it. What Are ...

  3. Travel Inside the Ear

    Full Text Available ... stirrup. These are the smallest bones in your body. Together they are smaller than an orange seed. It then travels into the inner ear, which ... organizations Related Topics ...

  4. Travel Inside the Ear

    Full Text Available Skip to main content U.S. Department of Health & Human Services National Institutes of Health Search Search form Search A–Z Index Español Menu Home Health Info Hearing, Ear Infections, and Deafness ...

  5. Age-related hearing loss: ear and brain mechanisms.

    Frisina, Robert D


    Loss of sensory function in the aged has serious consequences for economic productivity, quality of life, and healthcare costs in the billions each year. Understanding the neural and molecular bases will pave the way for biomedical interventions to prevent, slow, or reverse these conditions. This chapter summarizes new information regarding age changes in the auditory system involving both the ear (peripheral) and brain (central). A goal is to provide findings that have implications for understanding some common biological underpinnings that affect sensory systems, providing a basis for eventual interventions to improve overall sensory functioning, including the chemical senses.

  6. Ototoxicity (Ear Poisoning) (For Parents)

    ... Teaching Kids to Be Smart About Social Media Ototoxicity (Ear Poisoning) KidsHealth > For Parents > Ototoxicity (Ear Poisoning) Print A A A What's in ... result of taking the drugs. This is called ototoxicity or " ear poisoning ." Ototoxicity damages the inner ear — ...

  7. Sports injuries of the ear.

    Wagner, G A


    The author describes common sports injuries involving the ear. Such injuries include hematoma, lacerations, foreign bodies (tattoo), and thermal injuries. Ear canal injuries include swimmer's ear and penetrating injuries. Tympanum injuries include tympanic membrane perforations, ossicular discontinuity, eustachian tube dysfunction, temporal bone fractures and traumatic facial nerve palsy. Inner ear injuries include traumatic sensorineural deafness. The author emphasizes the management of these injuries.

  8. Flying and Your Child's Ears

    ... Media Flying and Your Child's Ears KidsHealth > For Parents > Flying and Your Child's Ears Print A A A What's in this article? Flying's Effects on Ears Tips for Easing Ear Pain en español Como cuidar los oídos de su hijo(a) cuando vuele en avión Flying's Effects on ...

  9. Brn3c null mutant mice show long-term, incomplete retention of some afferent inner ear innervation

    Pirvola Ulla


    Full Text Available Abstract Background Ears of Brn3c null mutants develop immature hair cells, identifiable only by certain molecular markers, and undergo apoptosis in neonates. This partial development of hair cells could lead to enough neurotrophin expression to sustain sensory neurons through embryonic development. We have therefore investigated in these mutants the patterns of innervation and of expression of known neurotrophins. Results At birth there is a limited expression of BDNF and NT-3 in the mutant sensory epithelia and DiI tracing shows no specific reduction of afferents or efferents that resembles neurotrophin null mutations. At postnatal day 7/8 (P7/8, innervation is severely reduced both qualitatively and quantitatively. 1% of myosin VIIa-positive immature hair cells are present in the mutant cochlea, concentrated in the base. Around 20% of immature hair cells exist in the mutant vestibular sensory epithelia. Despite more severe loss of hair cells (1% compared to 20%, the cochlea retains many more sensory neurons (46% compared to 15% than vestibular epithelia. Even 6 months old mutant mice have some fibers to all vestibular sensory epithelia and many more to the cochlear apex which lacks MyoVIIa positive hair cells. Topologically organized central cochlea projections exist at least until P8, suggesting that functional hair cells are not required to establish such projections. Conclusion The limited expression of neurotrophins in the cochlea of Brn3c null mice suffices to support many sensory neurons, particularly in the cochlea, until birth. The molecular nature of the long term survival of apical spiral neurons remains unclear.

  10. Rapid development of Purkinje cell excitability, functional cerebellar circuit, and afferent sensory input to cerebellum in zebrafish.

    Hsieh, Jui-Yi; Ulrich, Brittany; Issa, Fadi A; Wan, Jijun; Papazian, Diane M


    The zebrafish has significant advantages for studying the morphological development of the brain. However, little is known about the functional development of the zebrafish brain. We used patch clamp electrophysiology in live animals to investigate the emergence of excitability in cerebellar Purkinje cells, functional maturation of the cerebellar circuit, and establishment of sensory input to the cerebellum. Purkinje cells are born at 3 days post-fertilization (dpf). By 4 dpf, Purkinje cells spontaneously fired action potentials in an irregular pattern. By 5 dpf, the frequency and regularity of tonic firing had increased significantly and most cells fired complex spikes in response to climbing fiber activation. Our data suggest that, as in mammals, Purkinje cells are initially innervated by multiple climbing fibers that are winnowed to a single input. To probe the development of functional sensory input to the cerebellum, we investigated the response of Purkinje cells to a visual stimulus consisting of a rapid change in light intensity. At 4 dpf, sudden darkness increased the rate of tonic firing, suggesting that afferent pathways carrying visual information are already active by this stage. By 5 dpf, visual stimuli also activated climbing fibers, increasing the frequency of complex spiking. Our results indicate that the electrical properties of zebrafish and mammalian Purkinje cells are highly conserved and suggest that the same ion channels, Nav1.6 and Kv3.3, underlie spontaneous pacemaking activity. Interestingly, functional development of the cerebellum is temporally correlated with the emergence of complex, visually-guided behaviors such as prey capture. Because of the rapid formation of an electrically-active cerebellum, optical transparency, and ease of genetic manipulation, the zebrafish has great potential for functionally mapping cerebellar afferent and efferent pathways and for investigating cerebellar control of motor behavior.

  11. Disruption of SorCS2 reveals differences in the regulation of stereociliary bundle formation between hair cell types in the inner ear.

    Andrew Forge


    Full Text Available Behavioural anomalies suggesting an inner ear disorder were observed in a colony of transgenic mice. Affected animals were profoundly deaf. Severe hair bundle defects were identified in all outer and inner hair cells (OHC, IHC in the cochlea and in hair cells of vestibular macular organs, but hair cells in cristae were essentially unaffected. Evidence suggested the disorder was likely due to gene disruption by a randomly inserted transgene construct. Whole-genome sequencing identified interruption of the SorCS2 (Sortilin-related VPS-10 domain containing protein locus. Real-time-qPCR demonstrated disrupted expression of SorCS2 RNA in cochlear tissue from affected mice and this was confirmed by SorCS2 immuno-labelling. In all affected hair cells, stereocilia were shorter than normal, but abnormalities of bundle morphology and organisation differed between hair cell types. Bundles on OHC were grossly misshapen with significantly fewer stereocilia than normal. However, stereocilia were organised in rows of increasing height. Bundles on IHC contained significantly more stereocilia than normal with some longer stereocilia towards the centre, or with minimal height differentials. In early postnatal mice, kinocilia (primary cilia of IHC and of OHC were initially located towards the lateral edge of the hair cell surface but often became surrounded by stereocilia as bundle shape and apical surface contour changed. In macular organs the kinocilium was positioned in the centre of the cell surface throughout maturation. There was disruption of the signalling pathway controlling intrinsic hair cell apical asymmetry. LGN and Gαi3 were largely absent, and atypical Protein Kinase C (aPKC lost its asymmetric distribution. The results suggest that SorCS2 plays a role upstream of the intrinsic polarity pathway and that there are differences between hair cell types in the deployment of the machinery that generates a precisely organised hair bundle.

  12. Disruption of SorCS2 reveals differences in the regulation of stereociliary bundle formation between hair cell types in the inner ear

    Taylor, Ruth R.; Lovett, Michael; Jagger, Daniel J.


    Behavioural anomalies suggesting an inner ear disorder were observed in a colony of transgenic mice. Affected animals were profoundly deaf. Severe hair bundle defects were identified in all outer and inner hair cells (OHC, IHC) in the cochlea and in hair cells of vestibular macular organs, but hair cells in cristae were essentially unaffected. Evidence suggested the disorder was likely due to gene disruption by a randomly inserted transgene construct. Whole-genome sequencing identified interruption of the SorCS2 (Sortilin-related VPS-10 domain containing protein) locus. Real-time-qPCR demonstrated disrupted expression of SorCS2 RNA in cochlear tissue from affected mice and this was confirmed by SorCS2 immuno-labelling. In all affected hair cells, stereocilia were shorter than normal, but abnormalities of bundle morphology and organisation differed between hair cell types. Bundles on OHC were grossly misshapen with significantly fewer stereocilia than normal. However, stereocilia were organised in rows of increasing height. Bundles on IHC contained significantly more stereocilia than normal with some longer stereocilia towards the centre, or with minimal height differentials. In early postnatal mice, kinocilia (primary cilia) of IHC and of OHC were initially located towards the lateral edge of the hair cell surface but often became surrounded by stereocilia as bundle shape and apical surface contour changed. In macular organs the kinocilium was positioned in the centre of the cell surface throughout maturation. There was disruption of the signalling pathway controlling intrinsic hair cell apical asymmetry. LGN and Gαi3 were largely absent, and atypical Protein Kinase C (aPKC) lost its asymmetric distribution. The results suggest that SorCS2 plays a role upstream of the intrinsic polarity pathway and that there are differences between hair cell types in the deployment of the machinery that generates a precisely organised hair bundle. PMID:28346477

  13. Impact of Placement of In-the-Ear Antenna on Ear-to-Ear Path Gain

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper;


    An in-the-ear antenna is rotated in the concha. For the different placements the ear-to-ear path gain is simulated and measured. The simulations and measurements show that the ear-to-ear path gain varies with more than 15 dB even though it is the same antenna that occupies the same volume, which...... has only been rotated. This illustrates the importance of the correct placement of the antenna. The variation of the ear-to-ear path gain is compared with the far-field efficiency in order to explain part of the variation. The best and worst placements’ radiation patterns are analyzed....

  14. Inner ear disturbances related to middle ear inflammation

    Sone, Michihiko


    ABSTRACT The inner and middle ear are connected mainly through round and oval windows, and inflammation in the middle ear cavity can spread into the inner ear, which might induce a disturbance. In cases with intractable otitis media, attention should also be paid to symptoms related to the inner ear. In this paper, middle ear inflammation and related inner ear disturbances are reviewed with a focus on representative middle ear diseases (such as acute otitis media, chronic otitis media, otitis media with anti-neutrophil cytoplasmic antibody-associated vasculitis, eosinophilic otitis media, cholesteatoma with labyrinthine fistula, and reflux-related otitis media). Their clinical concerns are then discussed with reference to experimental studies. In these diseases, early diagnosis and adequate treatment are required to manage not only middle ear but also inner ear conditions.

  15. Damage and Repair in the Inner Ear: From Experimental Research to Clinical Aspects

    Bremer, H.G.


    In this thesis, fundamental research is performed on the sensory epithelia of the inner ear in guinea pigs and mice. The outcomes of these fundamental studies are discussed in relation to clinical vestibular research. Methods to efficiently, repeatedly and reproducibly damage the sensory epithelia o

  16. 莆田黑猪猪耳皮肤成纤维细胞系的建立%Establishment of Putian Black Piglets Ear Skin Fibroblast Cell Line

    张文昌; 谢旭东; 叶屹峰; 余翠月; 王秀爱; 刘凤军; 庄益芬; 马群; 邹长连; 洪志勇; 陈梅芳; 陈曦


      为获得可用于体细胞核移植中需要的供核细胞,利用组织块法培养莆田黑猪猪耳皮肤成纤维细胞,并对莆田黑猪猪耳皮肤成纤维细胞进行传代及冷冻。通过试验,获得能在体外正常传代培养的细胞系,为莆田黑猪克隆研究提供供核细胞来源。%  In order to get donor cells for somatic cells nuclear transfer ,Tissue piece culture dissociate ear skin fibroblast in Putian black pigs in this study,and transfer of culture and freezing.Through the study,We gained cell lines that can normally serial subcultivation in vitro which offer cell resources for Putian black pig clone research.

  17. MiR-182-5p protects inner ear hair cells from cisplatin-induced apoptosis by inhibiting FOXO3a

    Li, Yimeng; Li, Ao; Wu, Jingfang; He, Yingzi; Yu, Huiqian; Chai, Renjie; Li, Huawei


    Cisplatin is widely used for chemotherapy of a variety of malignancies. However, the clinical application of cisplatin is hampered by the resultant irreversible hearing loss due to hair cell apoptosis. To date, no practical regimen to resolve this has been developed. Meanwhile, the role of microRNA in protecting hair cells from cisplatin-induced apoptosis in the inner ear has not been extensively investigated. In this study, we monitored miR-183, -96, and -182 turnover in the cochlea during cisplatin treatment in vitro. We found that overexpression of miR-182, but not miR-183 and -96, improved hair cell survival after 3 μM cisplatin treatment in vitro. We demonstrated that overexpression of miR-182 repressed the intrinsic apoptotic pathway by inhibiting the translation of FOXO3a. Our study offers a new therapeutic target for alleviating cisplatin-induced hair cell apoptosis in a rapid and tissue-specific manner. PMID:27607577

  18. 大鼠内耳前体细胞的增殖研究%The Precursor Cells from the Inner Ear of SD Rats

    曾亮; 江红群


    目的:探讨不同年龄及生长因子对大鼠内耳前体细胞体外增殖的影响。方法①分离取出出生后1天(P1)、7天(P7)、14天(P14)、21天(P21)、30天(P30)、60天(P60)各天龄12只(24耳)SD大鼠的球囊斑、椭圆囊斑、Corti器的前体细胞,在无血清条件下进行单细胞悬浮培养,至第七天,在倒置相差显微镜下对所形成的细胞球进行计数;②取P1大鼠球囊斑、椭圆囊斑、Corti器高增殖细胞分为实验组和对照组,实验组分为四组,培养液分别添加表皮生长因子(epidermal growth factor ,EGF)、碱性成纤维细胞生长因子(basic fibroblast growth factor ,bF-GF)、胰岛素样生长因子-1(insulin-like growth factor -1,IGF -1)、白血病抑制因子(leukemia inhibitory factor , LIF),对照组不加生长因子,观察不同生长因子对细胞球数量的影响;③免疫荧光染色检测细胞球的表型特征。结果①P1SD大鼠内耳各器官单细胞表现为nestin阳性,培养7天后,可形成悬浮的细胞球,球体细胞免疫荧光表现为nestin和BrdU阳性;②耳蜗Corti器只在P1、P7可形成细胞球,而球囊斑、椭圆囊斑各天龄段均可形成细胞球;③培养液中添加EGF、bFGF、IGF-1组,培养形成的细胞球数量明显增多,与对照组比较,差异有显著统计学意义(P<0.01);添加LIF组则与对照组比较差异无统计学意义(P>0.05)。结论大鼠内耳球囊斑、椭圆囊斑以及耳蜗Corti器内有高增殖能力细胞,能表达神经干细胞的特性;随着鼠龄的增长,这种增殖能力总体表现为减退趋势;EGF、bFGF、IGF-1均可单独促进P1大鼠内耳前体细胞的增殖,而LIF无促增殖作用。%Objective To investigate the influence on the proliferation of the precursor cells from the inner ear of SD rats by different ages and growth factors in vitro .Methods The organs of

  19. Connexin-Mediated Signaling in Nonsensory Cells Is Crucial for the Development of Sensory Inner Hair Cells in the Mouse Cochlea

    Johnson, Stuart L.; Ceriani, Federico; Houston, Oliver; Polishchuk, Roman; Polishchuk, Elena; Crispino, Giulia; Zorzi, Veronica


    Mutations in the genes encoding for gap junction proteins connexin 26 (Cx26) and connexin 30 (Cx30) have been linked to syndromic and nonsyndromic hearing loss in mice and humans. The release of ATP from connexin hemichannels in cochlear nonsensory cells has been proposed to be the main trigger for action potential activity in immature sensory inner hair cells (IHCs), which is crucial for the refinement of the developing auditory circuitry. Using connexin knock-out mice, we show that IHCs fire spontaneous action potentials even in the absence of ATP-dependent intercellular Ca2+ signaling in the nonsensory cells. However, this signaling from nonsensory cells was able to increase the intrinsic IHC firing frequency. We also found that connexin expression is key to IHC functional maturation. In Cx26 conditional knock-out mice (Cx26Sox10-Cre), the maturation of IHCs, which normally occurs at approximately postnatal day 12, was partially prevented. Although Cx30 has been shown not to be required for hearing in young adult mice, IHCs from Cx30 knock-out mice exhibited a comprehensive brake in their development, such that their basolateral membrane currents and synaptic machinery retain a prehearing phenotype. We propose that IHC functional differentiation into mature sensory receptors is initiated in the prehearing cochlea provided that the expression of either connexin reaches a threshold level. As such, connexins regulate one of the most crucial functional refinements in the mammalian cochlea, the disruption of which contributes to the deafness phenotype observed in mice and DFNB1 patients. SIGNIFICANCE STATEMENT The correct development and function of the mammalian cochlea relies not only on the sensory hair cells, but also on the surrounding nonsensory cells. Although the nonsensory cells have been largely implicated in the general homeostasis in the mature cochlea, their involvement in the initial functional differentiation of the sensory inner hair cells is less

  20. [A case of adult T cell leukemia/lymphoma with motor and sensory polyneuropathy].

    Nakano, S; Ohnishi, A; Oishi, T; Murai, Y; Nagata, K


    A 62-year-old man was admitted to our hospital because of two months continuing paresthesia and muscle weakness of distal portions of the four limbs. On general physical examination, skin lesions, lymphadenopathy and hepatosplenomegaly were not found. Neurological examination revealed moderate weakness in the bilateral distal muscles of the lower limbs and left distal muscles of the upper limbs, and slight weakness in the right distal muscles of the upper limbs and the bilateral proximal muscles of the four limbs. Hand grasping powers were 24 kg and 2 kg on the right and left, respectively. The biceps, triceps and radial reflexes were decreased on the right, but normal on the left. The Achilles tendon reflex was decreased on the right and absent on the left. Paresthesia and superficial sensory disturbance were observed with glove and stocking distribution, which was more severe on the left side. The vibration and position senses were slightly decreased in the distal part of the lower limbs. On the laboratory examinations, serum anti-HTLV-I antibody was positive and no abnormal lymphocytes were observed in peripheral blood. Cerebrospinal fluid findings were normal, and anti-HTLV-I antibody was negative. Motor and sensory conduction velocities were normal or slightly decreased in all of the limb nerves examined, but the amplitudes of the compound muscle action potentials and the sensory nerve action potentials were asymmetrically decreased. Needle EMG showed fibrillation potentials and giant spikes with a reduction in number of motor unit potentials. The histological examination of the biopsied sural nerve revealed severe axonal degeneration without evidence of vasculitis or infiltration of abnormal lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. A Model for the representation of Speech Signals in Normal and Impaired Ears

    Christiansen, Thomas Ulrich


    A model of human auditory periphery, ranging from the outer ear to the auditory nerve, was developed. The model consists of the following components: outer ear transfer function, middle ear transfer function, basilar membrane velocity, inner hair cell receptor potential, inner hair cell probabili...

  2. [Inner Ear Hearing Loss].

    Hesse, G


    Hearing loss is one of the most dominant handicaps in modern societies, which additionally very often is not realized or not admitted. About one quarter of the general population suffers from inner ear hearing loss and is therefore restricted in communicational skills. Demographic factors like increasing age play an important role as well as environmental influences and an increasing sound and noise exposure especially in leisure activities. Thus borders between a "classical" presbyacusis - if it ever existed - and envirionmentally induced hearing loss disappear. Today restrictions in hearing ability develop earlier in age but at the same time they are detected and diagnosed earlier. This paper can eventually enlighten the wide field of inner ear hearing loss only fragmentarily; therefore mainly new research, findings and developments are reviewed. The first part discusses new aspects of diagnostics of inner ear hearing loss and different etiologies.

  3. Human embryonic stem cell-derived oligodendrocyte progenitors aid in functional recovery of sensory pathways following contusive spinal cord injury.

    Angelo H All

    Full Text Available BACKGROUND: Transplantations of human stem cell derivatives have been widely investigated in rodent models for the potential restoration of function of neural pathways after spinal cord injury (SCI. Studies have already demonstrated cells survival following transplantation in SCI. We sought to evaluate survival and potential therapeutic effects of transplanted human embryonic stem (hES cell-derived oligodendrocyte progenitor cells (OPCs in a contusive injury in rats. Bioluminescence imaging was utilized to verify survivability of cells up to 4 weeks, and somatosensory evoked potential (SSEPs were recorded at the cortex to monitor function of sensory pathways throughout the 6-week recovery period. PRINCIPAL FINDINGS: hES cells were transduced with the firefly luciferase gene and differentiated into OPCs. OPCs were transplanted into the lesion epicenter of rat spinal cords 2 hours after inducing a moderate contusive SCI. The hES-treatment group showed improved SSEPs, including increased amplitude and decreased latencies, compared to the control group. The bioluminescence of transplanted OPCs decreased by 97% in the injured spinal cord compared to only 80% when injected into an uninjured spinal cord. Bioluminescence increased in both experimental groups such that by week 3, no statistical difference was detected, signifying that the cells survived and proliferated independent of injury. Post-mortem histology of the spinal cords showed integration of human cells expressing mature oligodendrocyte markers and myelin basic protein without the expression of markers for astrocytes (GFAP or pluripotent cells (OCT4. CONCLUSIONS: hES-derived OPCs transplanted 2 hours after contusive SCI survive and differentiate into OLs that produce MBP. Treated rats demonstrated functional improvements in SSEP amplitudes and latencies compared to controls as early as 1 week post-injury. Finally, the hostile injury microenvironment at 2 hours post-injury initially caused

  4. Identification and characterization of an inner ear-expressed human melanoma inhibitory activity (MIA)-like gene (MIAL) with a frequent polymorphism that abolishes translation

    Rendtorff, Nanna Dahl; Frödin, M; Attié-Bitach, T


    in mammalian cell cultures showed that MIAL is translated as an approximately 15-kDa polypeptide that is assembled into a covalently linked homodimer, modified by sulfation, and secreted from the cells via the Golgi apparatus. In the human MIAL gene, a frequent polymorphism was discovered in the translation...... activity-like (MIAL; HGMW-approved symbol OTOR alias MIAL) gene. In situ hybridization revealed MIAL expression in a cell layer beneath the sensory epithelium of cochlea and vestibule of human fetal inner ear. No other human tissue, except fetal brain, showed expression of MIAL when analyzed by in situ...... hybridization or reverse transcription-polymerase chain reaction. The cDNA of the mouse homologue was also cloned and mapped about 80 cM from the top of mouse chromosome 2. In mouse, Mial was also expressed in the cochlea and the vestibule of the inner ear, as well as in brain, eye, limb, and ovary. Expression...

  5. Development and regeneration of the inner ear.

    Kwan, Tao; White, Patricia M; Segil, Neil


    Loss of sensory hair cells is the leading cause of deafness in humans. The mammalian cochlea cannot regenerate its complement of sensory hair cells. Thus at present, the only treatment for deafness due to sensory hair cell loss is the use of prosthetics, such as hearing aids and cochlear implants. In contrast, in nonmammalian vertebrates, such as birds, hair cell regeneration occurs following the death of hair cells and leads to the restoration of hearing. Regeneration in birds is successful because supporting cells that surround the hair cells can divide and are able to subsequently differentiate into new hair cells. However, supporting cells in mammals do not normally divide or transdifferentiate when hair cells are lost, and so regeneration does not occur. To understand the failure of mammalian cochlear hair cell regeneration, we need to understand the molecular mechanisms that underlie cell division control and hair cell differentiation, both during embryogenesis and in the postnatal mouse. In this review, we present a discussion of the regulation of cell proliferation in embryogenesis and during postnatal maturation. We also discuss the role of the Cip/Kip cell cycle inhibitors and Notch signaling in the control of stability of the differentiated state of early postnatal supporting cells. Finally, recent data indicate that some early postnatal mammalian supporting cells retain a latent capacity to divide and transdifferentiate into sensory hair cells. Together, these observations make supporting cells important therapeutic targets for continued efforts to induce hair cell regeneration.

  6. Ear, Hearing and Speech

    Poulsen, Torben


    An introduction is given to the the anatomy and the function of the ear, basic psychoacoustic matters (hearing threshold, loudness, masking), the speech signal and speech intelligibility. The lecture note is written for the course: Fundamentals of Acoustics and Noise Control (51001)......An introduction is given to the the anatomy and the function of the ear, basic psychoacoustic matters (hearing threshold, loudness, masking), the speech signal and speech intelligibility. The lecture note is written for the course: Fundamentals of Acoustics and Noise Control (51001)...

  7. Listening to the ear

    Shera, Christopher A.

    Otoacoustic emissions demonstrate that the ear creates sound while listening to sound, offering a promising acoustic window on the mechanics of hearing in awake, listening human beings. That window is clouded, however, by an incomplete knowledge of wave reflection and transmission, both forth and back within the cochlea and through the middle ear. This thesis "does windows," addressing wave propagation and scattering on both sides of the middle ear. A summary of highlights follows. Measurements of the cochlear input impedance in cat are used to identify a new symmetry in cochlear mechanics-termed "tapering symmetry" after its geometric interpretation in simple models-that guarantees that the wavelength of the traveling wave changes slowly with position near the stapes. Waves therefore propagate without reflection through the basal turns of the cochlea. Analytic methods for solving the cochlear wave equations using a perturbative scattering series are given and used to demonstrate that, contrary to common belief, conventional cochlear models exhibit negligible internal reflection whether or not they accurately represent the tapering symmetries of the inner ear. Frameworks for the systematic "deconstruction" of eardrum and middle-ear transduction characteristics are developed and applied to the analysis of noninvasive measurements of middle-ear and cochlear mechanics. A simple phenomenological model of inner-ear compressibility that correctly predicts hearing thresholds in patients with missing or disarticulated middle-ear ossicles is developed and used to establish an upper bound on cochlear compressibility several orders of magnitude smaller than that provided by direct measurements. Accurate measurements of stimulus frequency evoked otoacoustic emissions are performed and used to determine the form and frequency variation of the cochlear traveling-wave ratio noninvasively. Those measurements are inverted to obtain the spatial distribution of mechanical

  8. Osteogenesis for postoperative temporal bone defects using human ear adipose-derived stromal cells and tissue engineering: an animal model study.

    Kim, Yeon Ju; Park, Seung Gu; Shin, Beomyong; Kim, Jangho; Kim, Seung Won; Choo, Oak-Sung; Yin, Xiang Yun; Min, Byoung Hyun; Choung, Yun-Hoon


    Mastoidectomy, the removal of infected mastoid bones, is a common surgical procedure for the treatment of chronic otitis media. Persistent and recurrent otorrhea and accumulation of keratin debris following open cavity mastoidectomy are still bothersome issues for both patients and otologists. In this study, we used human ear adipose-derived stromal cells (hEASCs) in combination with polycaprolactone (PCL) scaffolds and osteogenic differentiation medium (ODM) to regenerate temporal bone defects. The hEASCs showed stem cell phenotypes, and these characteristics were maintained up to passage 5. Mastoid bulla and cranial bone defects were induced in Sprague-Dawley rats using AgNO3 and burr hole drilling, respectively, and the rats were then divided into five groups: (1) control, (2) hEASCs, (3) hEASCs + ODM, (4) hEASCs + PCL scaffolds, and (5) hEASCs + PCL scaffolds + ODM. Osteogenesis was evaluated by micro-computed tomography and histology. Compared with the control group, the groups transplanted with hEASCs and PCL scaffolds had significantly higher bone formation along the periphery of the mastoid bulla area. Moreover, ODM synergistically enhanced bone formation in mastoid bulla defects. Our results suggest that combining hEASCs with PCL scaffolds represents a promising method for anatomical and functional reconstruction of postoperative temporal bone defects following mastoidectomy. This article is protected by copyright. All rights reserved. © 2017 Wiley Periodicals, Inc.

  9. Sensory Substitution

    Verrillo, Ronald T.

    The idea that the cutaneous surface may be employed as a substitute for the eyes and ears is by no means a modern notion. Although the sense of touch has long been considered as a surrogate for both the visual and auditory modalities, the focus of this chapter will be on the efforts to develop a tactile substitute for hearing, especially that of human speech. The visual system is our primary means of processing information about environmental space such as orientation, distance, direction and size. It is much less effective in making temporal discriminations. The auditory system is unparalleled in processing information that involves rapid sequences of temporal events, such as speech and music. The tactile sense is capable of processing both spatial and temporal information although not as effective in either domain as the eye or the ear.

  10. [Effects of local transplantation of autologous adipose-derived mesenchymal stem cells on the formation of hyperplastic scar on rabbit ears].

    Chen, L; Wang, D L; Wei, Z R; Wang, B; Qi, J P; Sun, G F


    Objective: To investigate the effects of local transplantation of autologous adipose-derived mesenchymal stem cells (ADSCs) on the formation of hyperplastic scar on rabbit ears. Methods: ADSCs were isolated from inguinal fat of six New Zealand rabbits and then sub-cultured. ADSCs of the third passage of each rabbit were used in the following experiments. Six full-thickness skin defect wounds with diameter of 6 mm on the ventral surface of every rabbit ear were made. Wound healing and local-tissue proliferation were observed, and complete epithelization time of wounds and formation time of hyperplastic scar were recorded. The wounds on left ears were selected as group ADSCs, and the wounds on right ears were selected as control group, with 36 wounds in each group. After the complete epithelization of wounds (post injury day 25), 0.2 mL bromodeoxyuridine (BrdU) labeled autologous ADSCs with the concentration of 5×10(6) per milliliter were injected into each wound of the rabbit of group ADSCs, while the same amount of phosphate buffer solution was injected into each wound of the rabbit of control group. The frequency of injection was once every 5 days, totally for 3 times, and the latter 2 times were injected into scars generated from healed wound. Hyperplastic scars of rabbits of two groups were harvested on the fifth day after the third injection, then the morphology was observed by HE staining, and the arrangement of collagen in hyperplastic scar was observed by VG staining. The distribution of BrdU-labeled ADSCs in the hyperplastic scar was observed with fluorescence microscope. The protein content of type Ⅰ collagen, type Ⅲ collagen, transforming growth factor β1 (TGF-β1), and decorin in hyperplastic scar were detected by enzyme-linked immunosorbent assay, and the mRNA expression of decorin and TGF-β1 in hyperplastic scar were tested by real-time fluorescent quantitative reverse transcription-polymerase chain reaction. Data were processed with paired t

  11. Expression of cell wall related genes in basal and ear internodes of silking brown-midrib-3, caffeic acid O-methyltransferase (COMT down-regulated, and normal maize plants

    Martinant Jean-Pierre


    Full Text Available Abstract Background Silage maize is a major forage and energy resource for cattle feeding, and several studies have shown that lignin content and structure are the determining factors in forage maize feeding value. In maize, four natural brown-midrib mutants have modified lignin content, lignin structure and cell wall digestibility. The greatest lignin reduction and the highest cell wall digestibility were observed in the brown-midrib-3 (bm3 mutant, which is disrupted in the caffeic acid O-methyltransferase (COMT gene. Results Expression of cell wall related genes was investigated in basal and ear internodes of normal, COMT antisens (AS225, and bm3 maize plants of the INRA F2 line. A cell wall macro-array was developed with 651 gene specific tags of genes specifically involved in cell wall biogenesis. When comparing basal (older lignifying and ear (younger lignifying internodes of the normal line, all genes known to be involved in constitutive monolignol biosynthesis had a higher expression in younger ear internodes. The expression of the COMT gene was heavily reduced, especially in the younger lignifying tissues of the ear internode. Despite the fact that AS225 transgene expression was driven only in sclerenchyma tissues, COMT expression was also heavily reduced in AS225 ear and basal internodes. COMT disruption or down-regulation led to differential expressions of a few lignin pathway genes, which were all over-expressed, except for a phenylalanine ammonia-lyase gene. More unexpectedly, several transcription factor genes, cell signaling genes, transport and detoxification genes, genes involved in cell wall carbohydrate metabolism and genes encoding cell wall proteins, were differentially expressed, and mostly over-expressed, in COMT-deficient plants. Conclusion Differential gene expressions in COMT-deficient plants highlighted a probable disturbance in cell wall assembly. In addition, the gene expressions suggested modified chronology of the

  12. From Ear to Brain

    Kimura, Doreen


    In this paper Doreen Kimura gives a personal history of the "right-ear effect" in dichotic listening. The focus is on the early ground-breaking papers, describing how she did the first dichotic listening studies relating the effects to brain asymmetry. The paper also gives a description of the visual half-field technique for lateralized stimulus…

  13. Seeing With the Ears

    Koenderink, Jan


    In recent talks, I mentioned how my artist friends often complain that their clients see with their ears. It recently dawned on me that nobody understood what I said, or—worse—got the wrong idea. The audience thinks of bionic devices (Proulx, Stoerig, Ludowig, & Knoll, 2008) or bat echo location (Mo

  14. The role of hair follicle nestin-expressing stem cells during whisker sensory-nerve growth in long-term 3D culture.

    Mii, Sumiyuki; Duong, Jennifer; Tome, Yasunori; Uchugonova, Aisada; Liu, Fang; Amoh, Yasuyuki; Saito, Norimitsu; Katsuoka, Kensei; Hoffman, Robert M


    We have previously reported that nestin-expressing hair follicle stem cells can differentiate into neurons, Schwann cells, and other cell types. In the present study, vibrissa hair follicles, including their sensory nerve stump, were excised from transgenic mice in which the nestin promoter drives green fluorescent protein (ND-GFP mice), and were placed in 3D histoculture supported by Gelfoam®. β-III tubulin-positive fibers, consisting of ND-GFP-expressing cells, extended up to 500 µm from the whisker nerve stump in histoculture. The growing fibers had growth cones on their tips expressing F-actin. These findings indicate that β-III tubulin-positive fibers elongating from the whisker follicle sensory nerve stump were growing axons. The growing whisker sensory nerve was highly enriched in ND-GFP cells which appeared to play a major role in its elongation and interaction with other nerves in 3D culture, including the sciatic nerve, the trigeminal nerve, and the trigeminal nerve ganglion. The results of the present report suggest a major function of the nestin-expressing stem cells in the hair follicle is for growth of the follicle sensory nerve. Copyright © 2013 Wiley Periodicals, Inc.

  15. Mutation of Celsr1 disrupts planar polarity of inner ear hair cells and causes severe neural tube defects in the mouse.

    Curtin, John A; Quint, Elizabeth; Tsipouri, Vicky; Arkell, Ruth M; Cattanach, Bruce; Copp, Andrew J; Henderson, Deborah J; Spurr, Nigel; Stanier, Philip; Fisher, Elizabeth M; Nolan, Patrick M; Steel, Karen P; Brown, Steve D M; Gray, Ian C; Murdoch, Jennifer N


    We identified two novel mouse mutants with abnormal head-shaking behavior and neural tube defects during the course of independent ENU mutagenesis experiments. The heterozygous and homozygous mutants exhibit defects in the orientation of sensory hair cells in the organ of Corti, indicating a defect in planar cell polarity. The homozygous mutants exhibit severe neural tube defects as a result of failure to initiate neural tube closure. We show that these mutants, spin cycle and crash, carry independent missense mutations within the coding region of Celsr1, encoding a large protocadherin molecule [1]. Celsr1 is one of three mammalian homologs of Drosophila flamingo/starry night, which is essential for the planar cell polarity pathway in Drosophila together with frizzled, dishevelled, prickle, strabismus/van gogh, and rhoA. The identification of mouse mutants of Celsr1 provides the first evidence for the function of the Celsr family in planar cell polarity in mammals and further supports the involvement of a planar cell polarity pathway in vertebrate neurulation.

  16. Low-set ears and pinna abnormalities

    Low-set ears; Microtia; "Lop" ear; Pinna abnormalities; Genetic defect-pinna; Congenital defect-pinna ... conditions: Abnormal folds or location of the pinna Low-set ears No opening to the ear canal ...

  17. Ear, Nose & Throat Issues & Down Syndrome

    ... Throat Issues & Down Syndrome Ear, Nose & Throat Issues & Down Syndrome Ear, nose, and throat (ENT) problems are common ... What ENT Problems Are Common in Children With Down Syndrome? External Ear Canal Stenosis Stenotic ear canals (narrow ...

  18. The analysis of ear canals

    Ou, Gen

    In this thesis complex 3-D ear canal finite element models are simplified using transfer matrices to 1-D models. This simplification allows analysis on the sound propagation in the ear, which results in potentially using a non-invasive probe to determine the acoustical properties of the ear.

  19. Ear Acupuncture in European Traditional Medicine

    Luigi Gori


    Full Text Available Auricular acupuncture is a diagnostic and treatment system based on normalizing the body's dysfunction through stimulation of definite points on the ear. Rudimentary forms of acupuncture which probably arose during the Stone Age have survived in many parts of the world right down to present day. It was used in the ancient Egypt, Rome, Greece and all the Mediterranean area. It is a microacupuncture technique similar to reflexology, and was first described in France in 1950 by Paul Nogier who is considered the Father of modern ear acupuncture. It was speculated that the technique works because groups of pluripotent cells contain information from the whole organism and create regional organization centers representing different parts of the body. Nevertheless stimulation of a reflex point in the ear seems relieve symptoms of distant pathologies. Modern research is confirming the efficacy of ear acupuncture for analgesia and anxiety related disease, while tobacco dependence and other substance abuse still need confirmation. Actually main methodological problems with auricular acupuncture are that exist too many maps with little agreement regarding point location in the ear, and that the correspondence or reflex systems does not correlated with modern knowledge of anatomy and physiology.

  20. Carcinoid tumor of the middle ear.

    Nikanne, Elina; Kantola, Olli; Parviainen, Tapani


    Although carcinoid tumors are labeled as neuroendocrine tumors they can also originate in tissue lacking neuroendocrine cells, such as that in the middle ear. Symptoms of a carcinoid tumor in the middle ear are common ear symptoms such as fullness, pain and hearing loss. Carcinoid tumors have also been considered to be slow-growing. Both these aspects can easily lead to a relatively late diagnosis of carcinoid tumor of the middle ear. The diagnosis is made histologically, and the tumor is primarily treated surgically. In the follow-up of patients, octreotide scanning has proved to be a sensitive method in cases of both recurrence and metastasis. Our patient was a 34-year-old, otherwise healthy female with left-sided acute otitis media and facial palsy in her left ear. She had also suffered from the same symptoms 4 years earlier. She was treated with an operation, and the histologic diagnosis was a carcinoid tumor. In the follow-up of the patient we used octreotide scanning.

  1. Integration of transcriptomics, proteomics, and microRNA analyses reveals novel microRNA regulation of targets in the mammalian inner ear.

    Tal Elkan-Miller

    Full Text Available We have employed a novel approach for the identification of functionally important microRNA (miRNA-target interactions, integrating miRNA, transcriptome and proteome profiles and advanced in silico analysis using the FAME algorithm. Since miRNAs play a crucial role in the inner ear, demonstrated by the discovery of mutations in a miRNA leading to human and mouse deafness, we applied this approach to microdissected auditory and vestibular sensory epithelia. We detected the expression of 157 miRNAs in the inner ear sensory epithelia, with 53 miRNAs differentially expressed between the cochlea and vestibule. Functionally important miRNAs were determined by searching for enriched or depleted targets in the transcript and protein datasets with an expression consistent with the dogma of miRNA regulation. Importantly, quite a few of the targets were detected only in the protein datasets, attributable to regulation by translational suppression. We identified and experimentally validated the regulation of PSIP1-P75, a transcriptional co-activator previously unknown in the inner ear, by miR-135b, in vestibular hair cells. Our findings suggest that miR-135b serves as a cellular effector, involved in regulating some of the differences between the cochlear and vestibular hair cells.

  2. T-cell receptor genes in tassel-eared squirrels (Sciurus aberti). I. Genetic polymorphism and divergence in the Abert and Kaibab subspecies.

    Wettstein, P J; Chakraborty, R; States, J; Ferrari, G


    The role of environmental factors in the evolution and maintenance of diversity of antigen receptor gene families which participate in the immune response in mammals is inadequately understood. In order to elucidate the impact of these factors, we have undertaken the analysis of these gene families in the tassel-eared squirrel (Sciurus aberti) which has been separated into discrete subspecies by geographic barriers and whose food resources can be quantitated for estimating environmental quality. In this communication we describe the initial analysis of the complexity and polymorphism of sequences related to T-cell receptor (Tcr) alpha and beta chain genes in two subspecies, Sciurus aberti aberti (Abert) and Sciurus aberti kaibabensis (Kaibab) which have identical habitats and are separated by the Grand Canyon in Arizona, USA. Genomic blot analysis of 60 Abert and 62 Kaibab individuals collected over a 3-year period was performed with mouse Tcrb and Tcra cDNA probes. Sequences homologous to Tcrb-C, Tcrb-J1, and Tcrb-J2 genes were observed in all individuals from both subspecies; although Tcrb-J1 fragments were monomorphic. Tcrb-C and Tcrb-J2 fragments were polymorphic with both species- and subspecies-specific sequences. A single, monomorphic Tcra-C fragment was observed in addition to multiple Tcra-V fragments homologous to the mouse Tcra-V1 subfamily. Abert samples exhibited greater numbers of Tcra-V1 fragments as well as greater polymorphism than Kaibab samples. Heterozygosity estimates of Tcrb-C and Tcra-V1 sequences were determined for annually collected samples and compared with the yearly estimates of availability of hypogeous fungi, one of the major diet items of tassel-eared squirrels. In the Kaibab annual collections, Tcra-V1 heterozygosity declined with the decline in food resource, whereas heterozygosity of Tcrb-C sequences was inversely related to food resource. Similarly, a reduction in food resource for Abert squirrels in 1985 coincided with an

  3. The contralateral ear in cholesteatoma.

    da Costa, Sady Selaimen; Teixeira, Adriane Ribeiro; Rosito, Letícia Petersen Schmidt


    Middle ear cholesteatoma has been extensively studied. Theories of cholesteatoma pathogenesis involving previous tympanic membrane retraction are the most widely accepted, but the contralateral ear in patients with cholesteatoma remains unstudied. This study aimed to investigate the contralateral ear in patients with cholesteatoma, and to determine whether the characteristics of it differ according to patient age and cholesteatoma growth patterns. This study was cross sectional. We evaluated 356 patients with middle ear cholesteatoma in at least one ear, and no history of surgery, between August 2000 and March 2013. Otoendoscopy was conducted on both the affected and the contralateral ear. They were classified as normal, tympanic membrane perforation, moderate to severe tympanic membrane retraction and cholesteatoma. The mean age of the patients was 32.77 years, and 53.1 % of the cohort were female. Only 34.8 % of the contralateral ears were normal. The most common abnormality was moderate to severe tympanic membrane retraction (41.6 %). Cholesteatoma was identified in 16 %. Children exhibited a greater frequency of tympanic membrane retractions, whereas adults exhibited a greater frequency of cholesteatoma. All of the contralateral ears in the anterior epitympanic group were normal, but otherwise there were no differences in the contralateral ear when we compared the cholesteatoma growth patterns. We conclude that patients diagnosed with acquired cholesteatoma of one ear are significantly more likely to exhibit abnormalities of the contralateral ear.

  4. nEar 05

    S&C Labs


    Ego Systems简称ESI或Ego-Sys,这问韩国公司一向以制造低价格、高性能的专业音频产品闻名于专业音频制作领域。其产品涵盖了专业录音卡、监听音箱和USB声卡等。在大家的印象中,可能还记得MAYA录音卡、nEar 08监听音箱,以及MAYA EX系列USB声卡。其中,nEar08监听音箱曾在本刊2001年第18期报道过,那是它首次在国内媒体上亮相。经过四年多的市场检验,

  5. Van Gogh and Frizzled act redundantly in the Drosophila sensory organ precursor cell to orient its asymmetric division.

    José-Eduardo Gomes

    Full Text Available Drosophila sensory organ precursor cells (SOPs divide asymmetrically along the anterior-posterior (a-p body axis to generate two different daughter cells. Planar Cell Polarity (PCP regulates the a-p orientation of the SOP division. The localization of the PCP proteins Van Gogh (Vang and Frizzled (Fz define anterior and posterior apical membrane domains prior to SOP division. Here, we investigate the relative contributions of Vang, Fz and Dishevelled (Dsh, a membrane-associated protein acting downstream of Fz, in orienting SOP polarity. Genetic and live imaging analyses suggest that Dsh restricts the localization of a centrosome-attracting activity to the anterior cortex and that Vang is a target of Dsh in this process. Using a clone border assay, we provide evidence that the Vang and fz genes act redundantly in SOPs to orient its polarity axis in response to extrinsic local PCP cues. Additionally, we find that the activity of Vang is dispensable for the non-autonomous polarizing activity of fz. These observations indicate that both Vang and Fz act as cues for downstream effectors orienting the planar polarity axis of dividing SOPs.

  6. ePPR: a new strategy for the characterization of sensory cells from input/output data.

    Rapela, Joaquín; Felsen, Gidon; Touryan, Jon; Mendel, Jerry M; Grzywacz, Norberto M


    A central goal of systems neuroscience is to characterize the transformation of sensory input to spiking output in single neurons. This problem is complicated by the large dimensionality of the inputs. To cope with this problem, previous methods have estimated simplified versions of a generic linear-nonlinear (LN) model and required, in most cases, stimuli with constrained statistics. Here we develop the extended Projection Pursuit Regression (ePPR) algorithm that allows the estimation of all of the parameters, in space and time, of a generic LN model using arbitrary stimuli. We first prove that ePPR models can uniformly approximate, to an arbitrary degree of precision, any continuous function. To test this generality empirically, we use ePPR to recover the parameters of models of cortical cells that cannot be represented exactly with an ePPR model. Next we evaluate ePPR with physiological data from primary visual cortex, and show that it can characterize both simple and complex cells, from their responses to both natural and random stimuli. For both simulated and physiological data, we show that ePPR compares favorably to spike-triggered and information-theoretic techniques. To the best of our knowledge, this article contains the first demonstration of a method that allows the estimation of an LN model of visual cells, containing multiple spatio-temporal filters, from their responses to natural stimuli.

  7. Gap junctions in the inner ear: comparison of distribution patterns in different vertebrates and assessement of connexin composition in mammals.

    Forge, Andrew; Becker, David; Casalotti, Stefano; Edwards, Jill; Marziano, Nerissa; Nevill, Graham


    The distribution and size of gap junctions (GJ) in the sensory epithelia of the inner ear have been examined in a reptile (gecko), birds (chicken and owl), and mammals (mouse, guinea pig, gerbil, and bat), and the connexin composition of GJs in the mammalian inner ear has been assessed. Freeze fracture revealed a common pattern of GJ distribution in auditory and vestibular sensory epithelia in the different vertebrate classes. In all these tissues, GJs are numerous, often occupying more than 25% of the plasma membrane area of supporting cells and sometimes composed of more than 100,000 channels. Screening for 12 members of the connexin family in the mammalian inner ear by RT-PCR, Western blotting, and immunohistochemistry revealed four connexin isotypes, cx26, cx30, cx31, and cx43, in the cochlea and three, cx26, cx30, and cx43, in the vestibular organs. With antibodies characterised for their specificity, cx26 and cx30 colocalised in supporting cells of the organ of Corti, in the basal cell region of the stria vascularis, and in type 1 fibrocytes of the spiral ligament. No other connexin was detected in these regions. Cx31 was localised among type 2 fibrocytes below the spiral prominence, a region where cx30 was not expressed and cx26 expression appeared to be low. Cx43 was detected only in the region of "tension fibrocytes" lining the inner aspect of the otic capsule. This suggests separate functional compartments in the cochlea. In addition to cx26 and cx30, cx43 was detected in supporting cells of the vestibular sensory epithelia. Where cx26 and cx30 were colocalised, double immunogold labelling of thin sections showed both cx26 and cx30 evenly distributed in individual GJ plaques, a pattern consistent with the presence of heteromeric connexons. Coimmunoprecipitation of cochlear membrane proteins solubilised with a procedure that preserves the oligomeric structure of connexons confirmed the presence of heteromeric cx26/cx30 connexons. Heteromeric cx26/cx30

  8. Quantitative sensory testing and pain-evoked cytokine reactivity: comparison of patients with sickle cell disease to healthy matched controls.

    Campbell, Claudia M; Carroll, C Patrick; Kiley, Kasey; Han, Dingfen; Haywood, Carlton; Lanzkron, Sophie; Swedberg, Lauren; Edwards, Robert R; Page, Gayle G; Haythornthwaite, Jennifer A


    Sickle cell disease (SCD) is an inherited blood disorder associated with significant morbidity, which includes severe episodic pain, and, often, chronic pain. Compared to healthy individuals, patients with SCD report enhanced sensitivity to thermal detection and pain thresholds and have altered inflammatory profiles, yet no studies to date have examined biomarker reactivity after laboratory-induced pain. We sought to examine this relationship in patients with SCD compared to healthy control participants. We completed quantitative sensory testing in 83 patients with SCD and sequential blood sampling in 27 of them, whom we matched (sex, age, race, body mass index, and education) to 27 healthy controls. Surprisingly, few quantitative sensory testing differences emerged between groups. Heat pain tolerance, pressure pain threshold at the trapezius, thumb, and quadriceps, and thermal temporal summation at 45°C differed between groups in the expected direction, whereas conditioned pain modulation and pain ratings to hot water hand immersion were counterintuitive, possibly because of tailoring the water temperature to a perceptual level; patients with SCD received milder temperatures. In the matched subsample, group differences and group-by-time interactions were observed in biomarkers including tumor necrosis factor alpha, interleukin-1ß, interleukin-4, and neuropeptide Y. These findings highlight the utility of laboratory pain testing methods for understanding individual differences in inflammatory cytokines. Our findings suggest amplified pain-evoked proinflammatory cytokine reactivity among patients with SCD relative to carefully matched controls. Future research is warranted to evaluate the impact of enhanced pain-related cytokine response and whether it is predictive of clinical characteristics and the frequency/severity of pain crises in patients with SCD.

  9. Action of angiotensin II, 5-hydroxytryptamine and adenosine triphosphate on ionic currents in single ear artery cells of the rabbit.

    Hughes, A D; Bolton, T B


    1. Angiotensin II, 5-hydroxytryptamine (5-HT) and adenosine triphosphate (ATP) evoked a transient inward current in isolated single car artery cells of rabbit held at -60 mV by whole cell voltage clamp in physiological saline using a KCL-containing pipette solution. Under these conditions agonist did not activate a calcium-dependent potassium current. 2. Responses to each agonist were transient and desensitized rapidly. Inward current at -60 mV holding potential was not abolished by blockade of voltage-dependent calcium channels or by buffering intracellular calcium with BAPTA, a calcium chelator, or following depletion of intracellular calcium stores with ryanodine. 3. The shape of the current-voltage relationships and the reversal potentials of the current induced by angiotensin II, 5-HT and ATP were similar under a variety of ionic conditions. Agonist-induced current was unaffected by replacing intracellular chloride with citrate ions or by replacing intracellular sodium with caesium or extracellular sodium with barium or calcium. Replacement of extracellular sodium with Tris shifted the reversal potential in all cases by around 30 mV negatively. 4. These data suggest that angiotensin II, 5-HT and ATP activate similar cationic conductances which are relatively non-selective allowing mono- and divalent cations to cross the smooth muscle cell membrane. These channels may allow the influx of calcium under physiological conditions.

  10. Sensory transduction in eukaryotes : A comparison between Dictyosteliurn and vertebrate cells

    Haastert, Peter J.M. van; Janssens, Pim M.W.; Erneux, Christophe


    The organization of multicellular organisms depends on cell-cell communication. The signal molecules are often soluble components in the extracellular fluid, but also include odors and light. A large array of surface receptors is involved in the detection of these signals. Signals are then transduce

  11. CD8 T Cell Sensory Adaptation Dependent on TCR Avidity for Self-Antigens

    Marquez, M.-E.; Ellmeier, W.; Sanchez-Guajardo, Vanesa Maria


    Adaptation of the T cell activation threshold may be one mechanism to control autoreactivity. To investigate its occurrence in vivo, we engineered a transgenic mouse model with increased TCR-dependent excitability by expressing a Zap70 gain-of-function mutant (ZAP-YEEI) in postselection CD8...... thymocytes and T cells. Increased basal phosphorylation of the Zap70 substrate linker for activation of T cells was detected in ZAP-YEEI-bearing CD8 T cells. However, these cells were not activated, but had reduced levels of TCR and CD5. Moreover, they produced lower cytokine amounts and showed faster...... adaptation was studied by expressing ZAP-YEEI in P14 or HY TCR transgenic backgrounds. Unexpectedly, double-transgenic animals expressed ZAP-YEEI prematurely in double-positive thymocytes, but no overt alteration of selection processes was observed. Instead, modifications of TCR and CD5 expression due to ZAP...

  12. Dissection of inner ear neuroepithelium in zebrafish%斑马鱼内耳感觉上皮分离术

    田永胜; 张旭; 陈晓巍


    Objective To establish a model by using zebrafish for the inner ear development and disease research,to explore the possibility of complete dissection of inner ear neuroepithelium in zebrafish by surface preparation of inner ear maculae.Methods The inner ear samples of zebra fish were fixed followed by harvesting.After decalcified and dehydrated,the coronal cryosections were made at 3 μm thickness at -23℃ using cryostat,the hematoxylin and eosin staining and immnofluorescence and histochemistry staining were performed,the saccules,utricles and lagenaes were successfully obtained by fine dissection.The sensory maculae were mounted on glass and then were stained.Results After hematoxylin and eosin staining and immnofluorescence and histochemistry staining of cryosections,the sensory maculae of inner ear could be determined by otoliths.On the basis of distinguish of otoliths,the sensory maculae of inner ear could be finely dissected,the overall intergrity of the sensory maculae could be preserved completely.After immnofluorescence and histochemistry staining,intact epithelia with strong hair cell bundle staining could be seen.Conclusions The neuroepithelium hair cell examination of zebra fish can be entirely attained by surface preparation of inner ear maculae.%目的 探索斑马鱼内耳感觉上皮的分离方法,为采用斑马鱼作为内耳发育及疾病研究的动物模型提供技术手段.方法 取4个月龄斑马鱼进行内耳组织冰冻切片,HE染色确定内耳感觉囊斑部位,并行免疫荧光染色观察毛细胞纤毛.在解剖显微镜下将斑马鱼内耳椭圆囊、球囊及听壶完整分离,取出内耳感觉囊斑平铺于载玻片中,进行免疫荧光染色,观察内耳感觉囊斑铺片的形态结构.结果 冰冻切片证实斑马鱼内耳感觉上皮位于囊斑内,并与耳石相对应.以耳石为标志分离出完整的内耳感觉囊斑组织,铺片免疫荧光染色后可观察到内耳感觉上皮形态结构完整,毛细

  13. [The tempestuous history of middle ear operation].

    Betlejewski, Stanisław; Betlejewski, Andrzej


    The paper is a review of primary and secondary historical and scientific literature concerning the surgical treatment of the middle ear diseases. The development of mastoid surgery can be traced through the past 4 centuries. Once used as a means of evacuating a postauricular abscess, it has evolved to become a method for gaining entry into the middle ear to control acute and chronic ear diseases, or for treatment of otogenic complications. Earlier works led the way to the postauricular "Wilde incision", which gave rise to Schwartze mastoidectomy. Oscar Wilde's ultimate demise from an otogenic meningitis appears all the more ironic when one considers the role his father, Sir William Wilde, played as one of the founding fathers of modern otology. The death of baron von Berger after mastoidectomy performed for treatment of tinnitus and hypacusis, stopped the further development of surgical procedures for about hundred years. The Joseph Toynbee's "Diseases of the ear" was the first work about ear diseases on a pathologic anatomical base, and fundamental for otology of the German speaking countries in the nineteenth and early twentieth centuries. Otology was emerging as a specific specialty. Von Tröltsch was the first surgeon, who proposed the antral opening through the external ear canal. When Schwartze and his assistant, Eysell, published their paper: "On the Artificial Opening of the Mastoid Air Cells," a century or so had passed since the few previous attempts to remove the tegmen of the mastoid had been reported. One of the greatest otologists of the 19th century was Adam Politzer, His influence on the 50 years of otology has never been equaled. It is in his honor that the International Society of Otology bears his name.

  14. Effect of receptor potential on mechanical oscillations in a model of sensory hair cell

    Khamesian, Mahvand; Neiman, Alexander B.


    Hair cells mediating the senses of hearing and balance rely on active mechanisms for amplification of mechanical signals. In amphibians, hair cells exhibit spontaneous self-sustained mechanical oscillations of their hair bundles. We study the response of the mechanical oscillations to perturbation of the cell's membrane potential in a model for hair bundle of bullfrog saccular hair cells. We identify bifurcation mechanism leading to mechanical oscillations using the membrane potential and the strength of fast adaptation as control parameters and then compute static and dynamic sensitivity of mechanical oscillations to voltage variations. We show that fast adaptation results in the static sensitivity of oscillating hair bundles in the range 0.1-0.2 nm/mV, consistent with recent experimental work. Predicted dynamic response of oscillating hair bundle to voltage variations is characterized by the values of sensitivity of up to 2 nm/mV, enhanced by the presence of fast adaptation.

  15. Modelling Effects on Grid Cells of Sensory Input During Self-motion


    rhythm oscillations are reduced by inactivation of the medial septum (Brandon et al. 2011; Koenig et al. 2011). It is not yet clear which cell...B, simulated box environment for boundary vector cells. The coordinate system (red, blue and green arrows) indicates the initial position and...wall ( blue dots). This optic flow field is used to estimate the linear and rotational velocity of the rat as well as the distance of the wall in ego

  16. Fgf19 expression patterns in the developing chick inner ear.

    Sánchez-Calderón, Hortensia; Francisco-Morcillo, Javier; Martín-Partido, Gervasio; Hidalgo-Sánchez, Matías


    The inner ear is a complex sensorial structure with hearing and balance functions. A key aim of developmental biology is to understand the molecular and cellular mechanisms involved in the induction, patterning and innervation of the vertebrate inner ear. These developmental events could be mediated by the expression of regulating genes, such as the members of the family of Fibroblast Growth Factors (Fgfs). This work reports the detailed spatial and temporal patterns of Fgf19 expression in the developing inner ear from otic cup (stage 14) to 8 embryonic days (stage 34). In the earliest stages, Fgf19 and Fgf8 expressions determine two subdomains within the Fgf10-positive proneural-sensory territory. We show that, from the earliest stages, the Fgf19 expression was detected in the acoustic-vestibular ganglion and the macula utriculi. The Fgf19 gene was also strongly, but transiently, expressed in the macula lagena, whereas the macula neglecta never expressed this gene in the period analysed. The Fgf19 expression was also clearly observed in some borders of various sensory elements. These results could be useful from further investigations into the role of FGF19 in otic patterning.

  17. Single-cell coding of sensory, spatial and numerical magnitudes in primate prefrontal, premotor and cingulate motor cortices.

    Eiselt, Anne-Kathrin; Nieder, Andreas


    The representation of magnitude information enables humans and animal species alike to successfully interact with the external environment. However, how various types of magnitudes are processed by single neurons to guide goal-directed behavior remains elusive. Here, we recorded single-cell activity from the dorsolateral prefrontal (PFC), dorsal premotor (PMd) and cingulate motor (CMA) cortices in monkeys discriminating discrete numerical (numerosity), continuous spatial (line length) and basic sensory (spatial frequency) stimuli. We found that almost exclusively PFC neurons represented the different magnitude types during sample presentation and working memory periods. The frequency of magnitude-selective cells in PMd and CMA did not exceed chance level. The proportion of PFC neurons selectively tuned to each of the three magnitude types were comparable. Magnitude coding was mainly dissociated at the single-neuron level, with individual neurons representing only one of the three tested magnitude types. Neuronal magnitude discriminability, coding strength and temporal evolution were comparable between magnitude types encoded by PFC neuron populations. Our data highlight the importance of PFC neurons in representing various magnitude categories. Such magnitude representations are based on largely distributed coding by single neurons that are anatomically intermingled within the same cortical area.

  18. Classification and diagnosis of ear malformations

    Bartel-Friedrich, Sylva; Wulke, Cornelia


    In the ENT region 50% of the malformations affect the ear. Malformations of the outer and middle ear are predominantly unilateral (ca. 70-90%) and mostly involve the right ear. Inner ear malformations can be unilateral or bilateral. The incidence of ear malformations is approximately 1 in 3800 newborns. Ear malformations may be genetic (associated with syndromes or not, with family history, spontaneous mutations) or acquired in nature. Malformations can affect the outer ear (pinna and externa...

  19. Simple ears-flexible behavior: Information processing in the moth auditory pathway

    Gerit PFUHL; Blanka KALINOVA; Irena VALTEROVA; Bente G.BERG


    Lepidoptera evolved tympanic ears in response to echolocating bats.Comparative studies have shown that moth ears evolved many times independently from chordotonal organs.With only 1 to 4 receptor cells,they are one of the simplest hearing organs.The small number of receptors does not imply simplicity,neither in behavior nor in the neural circuit.Behaviorally,the response to ultrasound is far from being a simple reflex.Moths' escape behavior is modulated by a variety of cues,especially pheromones,which can alter the auditory response.Neurally the receptor cell(s) diverges onto many intemeurons,enabling pa rallel processing and feature extraction.Ascending interneurons and sound-sensitive brain neurons innervate a neuropil in the ventrolateral protocerebrum.Further,recent electrophysiological data provides the first glimpses into how the acoustic response is modulated as well as how ultrasound influences the other senses.So far,the auditory pathway has been studied in noctuids.The findings agree well with common computational principles found in other insects.However,moth ears also show unique mechanical and neural adaptation.Here,we first describe the variety of moths' auditory behavior,especially the co-option of ultrasonic signals for intraspecific communication.Second,we describe the current knowledge of the neural pathway gained from noctuid moths.Finally,we argue that Galleriinae which show negative and positive phonotaxis,are an interesting model species for future electrophysiological studies of the auditory pathway and multimodal sensory integration,and so are ideally suited for the study of the evolution of behavioral mechanisms given a few receptors [Current Zoology 61 (2):292-302,2015].

  20. Phosphatidylserine-positive particles in the apical domain of sensory hair cells

    SHI Xiao-rui; Alfred Nuttall


    Apical membrane recycling has been proposed to be important for normal hair cell function. The current study reports an in vitro work that demonstrates the presence of phosphatidylserine (PS) and PS-positive vesicles labeled by Annexin V in the apical portion of hair cells. The following characteristics of the PS-positive vesicles were noticed using scanning confocal fluorescence microscopy: (1) variable sizes around 200 nm; (2)variable distribution patterns (either uniformly along individual stereocilia in the hair bundle or irregular) in the stereocilia from cell to cell; (3) variable sizes and numbers at locations along the border of the cuticular plate (CP),with a large number of them located at the vestigal kinocilial location; (4) motility with some of the vesicles during the observation period; (5) increase in PS labeling and the number of PS-positive vesicles after loud sound stimulation; and (6) decreased PS labeling and PS-positive vesicle numbers following treatment with LY-294002, a PI3 -kinase inhibitor. These results suggest that the presence of PS-positive vesicles at the apical area of hair cells may be indicative of vesicle shedding or transportation of a protein or rafts.

  1. The effect of hair bundle shape on hair bundle hydrodynamics of non-mammalian inner ear hair cells for the full frequency range.

    Shatz, Lisa F


    The effect of the size and the shape of the hair bundle of a hair cell in the inner ear of non-mammals on its motion for the full range of frequencies is determined thereby extending the results of a previous analysis of hair bundle motion for high and low frequencies [Hear Res. 141 (2000) 39-50]. A hemispheroid is used to represent the hair bundle because it can represent a full range of shapes, from thin, pencil-like shapes to wide, flat, disk-like shapes. Boundary element methods are used to approximate the solution for the hydrodynamics. For physiologically relevant parameters, an excellent match is obtained between the model's predictions and measurements of hair bundle motion in the free-standing region of the basilar papilla of the alligator lizard [Aranyosi, Measuring sound-induced motions of the alligator lizard cochlea. Massachusetts Institute of Technology, PhD Thesis, 2002]. Neither in the model's predictions nor in experimental measurements is sharp tuning observed. The model predicted the low frequency region of neural tuning curves for the alligator lizard and bobtail lizard, but could not predict the sharp tuning or the high frequency region. An element that represents an active mechanism is added to the hair bundle model to predict neural tuning curves, which are sharply tuned, and an excellent match is obtained for all the characteristics of neural tuning curves for the alligator lizard, and for the low and high frequency regions for the bobtail lizard. The model does not predict well the sharp tuning of the shorter hair bundles of the bobtail lizard, possibly because it does not represent tectorial sallets.

  2. An in vitro model of murine middle ear epithelium

    Apoorva Mulay


    Full Text Available Otitis media (OM, or middle ear inflammation, is the most common paediatric disease and leads to significant morbidity. Although understanding of underlying disease mechanisms is hampered by complex pathophysiology it is clear that epithelial abnormalities underpin the disease. There is currently a lack of a well-characterised in vitro model of the middle ear (ME epithelium that replicates the complex cellular composition of the middle ear. Here, we report the development of a novel in vitro model of mouse middle ear epithelial cells (mMECs at an air–liquid interface (ALI that recapitulates the characteristics of the native murine ME epithelium. We demonstrate that mMECs undergo differentiation into the varied cell populations seen within the native middle ear. Proteomic analysis confirmed that the cultures secrete a multitude of innate defence proteins from their apical surface. We showed that the mMECs supported the growth of the otopathogen, nontypeable Haemophilus influenzae (NTHi, suggesting that the model can be successfully utilised to study host–pathogen interactions in the middle ear. Overall, our mMEC culture system can help to better understand the cell biology of the middle ear and improve our understanding of the pathophysiology of OM. The model also has the potential to serve as a platform for validation of treatments designed to reverse aspects of epithelial remodelling that underpin OM development.

  3. Clonal Expansion of Lgr5-Positive Cells from Mammalian Cochlea and High-Purity Generation of Sensory Hair Cells

    Will J. McLean


    Full Text Available Death of cochlear hair cells, which do not regenerate, is a cause of hearing loss in a high percentage of the population. Currently, no approach exists to obtain large numbers of cochlear hair cells. Here, using a small-molecule approach, we show significant expansion (>2,000-fold of cochlear supporting cells expressing and maintaining Lgr5, an epithelial stem cell marker, in response to stimulation of Wnt signaling by a GSK3β inhibitor and transcriptional activation by a histone deacetylase inhibitor. The Lgr5-expressing cells differentiate into hair cells in high yield. From a single mouse cochlea, we obtained over 11,500 hair cells, compared to less than 200 in the absence of induction. The newly generated hair cells have bundles and molecular machinery for transduction, synapse formation, and specialized hair cell activity. Targeting supporting cells capable of proliferation and cochlear hair cell replacement could lead to the discovery of hearing loss treatments.

  4. Ear Recognition Based on Gabor Features and KFDA

    Li Yuan; Zhichun Mu


    We propose an ear recognition system based on 2D ear images which includes three stages: ear enrollment, feature extraction, and ear recognition. Ear enrollment includes ear detection and ear normalization. The ear detection approach based on improved Adaboost algorithm detects the ear part under complex background using two steps: offline cascaded classifier training and online ear detection. Then Active Shape Model is applied to segment the ear part and normalize all the ear images to the s...

  5. Pressure difference receiving ears

    Michelsen, Axel; Larsen, Ole Næsbye


    of such pressure difference receiving ears have been hampered by lack of suitable experimental methods. In this review, we review the methods for collecting reliable data on the binaural directional cues at the eardrums, on how the eardrum vibrations depend on the direction of sound incidence, and on how sound...... waves behave in the air spaces leading to the interior surfaces of eardrums. A linear mathematical model with well-defined inputs is used for exploring how the directionality varies with the binaural directional cues and the amplitude and phase gain of the sound pathway to the inner surface...

  6. The ear: Diagnostic imaging

    Vignaud, J.; Jardin, C.; Rosen, L.


    This is an English translation of volume 17-1 of Traite de radiodiagnostic and represents a reasonably complete documentation of the diseases of the temporal bone that have imaging manifestations. The book begins with chapters on embryology, anatomy and radiography anatomy; it continues with blood supply and an overview of temporal bone pathology. Subsequent chapters cover malformations, trauma, infections, tumors, postoperative changes, glomus tumors, vertebasilar insufficiency, and facial nerve canal lesions. A final chapter demonstrates and discusses magnetic resonance images of the ear and cerebellopontine angle.

  7. The Evolution of Sensory Placodes

    Francoise Mazet


    Full Text Available The vertebrate cranial sensory placodes are ectodermal embryonic patches that give rise to sensory receptor cells of the peripheral paired sense organs and to neurons in the cranial sensory ganglia. Their differentiation and the genetic pathways that underlay their development are now well understood. Their evolutionary history, however, has remained obscure. Recent molecular work, performed on close relatives of the vertebrates, demonstrated that some sensory placodes (namely the adenohypophysis, the olfactory, and accoustico-lateralis placodes first evolved at the base of the chordate lineage, while others might be specific to vertebrates. Combined with morphological and cellular fate data, these results also suggest that the sensory placodes of the ancestor of all chordates differentiated into a wide range of structures, most likely to fit the lifestyle and environment of each species.

  8. Histone deacetylase 1 is required for the development of the zebrafish inner ear

    He, Yingzi; Tang, Dongmei; Li, Wenyan; Chai, Renjie; Li, Huawei


    Histone deacetylase 1 (HDAC1) has been reported to be important for multiple aspects of normal embryonic development, but little is known about its function in the development of mechanosensory organs. Here, we first confirmed that HDAC1 is expressed in the developing otic vesicles of zebrafish by whole-mount in situ hybridization. Knockdown of HDAC1 using antisense morpholino oligonucleotides in zebrafish embryos induced smaller otic vesicles, abnormal otoliths, malformed or absent semicircular canals, and fewer sensory hair cells. HDAC1 loss of function also caused attenuated expression of a subset of key genes required for otic vesicle formation during development. Morpholino-mediated knockdown of HDAC1 resulted in decreased expression of members of the Fgf family in the otic vesicles, suggesting that HDAC1 is involved in the development of the inner ear through regulation of Fgf signaling pathways. Taken together, our results indicate that HDAC1 plays an important role in otic vesicle formation. PMID:26832938

  9. Synaptic inputs from stroke-injured brain to grafted human stem cell-derived neurons activated by sensory stimuli.

    Tornero, Daniel; Tsupykov, Oleg; Granmo, Marcus; Rodriguez, Cristina; Grønning-Hansen, Marita; Thelin, Jonas; Smozhanik, Ekaterina; Laterza, Cecilia; Wattananit, Somsak; Ge, Ruimin; Tatarishvili, Jemal; Grealish, Shane; Brüstle, Oliver; Skibo, Galina; Parmar, Malin; Schouenborg, Jens; Lindvall, Olle; Kokaia, Zaal


    Transplanted neurons derived from stem cells have been proposed to improve function in animal models of human disease by various mechanisms such as neuronal replacement. However, whether the grafted neurons receive functional synaptic inputs from the recipient's brain and integrate into host neural circuitry is unknown. Here we studied the synaptic inputs from the host brain to grafted cortical neurons derived from human induced pluripotent stem cells after transplantation into stroke-injured rat cerebral cortex. Using the rabies virus-based trans-synaptic tracing method and immunoelectron microscopy, we demonstrate that the grafted neurons receive direct synaptic inputs from neurons in different host brain areas located in a pattern similar to that of neurons projecting to the corresponding endogenous cortical neurons in the intact brain. Electrophysiological in vivo recordings from the cortical implants show that physiological sensory stimuli, i.e. cutaneous stimulation of nose and paw, can activate or inhibit spontaneous activity in grafted neurons, indicating that at least some of the afferent inputs are functional. In agreement, we find using patch-clamp recordings that a portion of grafted neurons respond to photostimulation of virally transfected, channelrhodopsin-2-expressing thalamo-cortical axons in acute brain slices. The present study demonstrates, for the first time, that the host brain regulates the activity of grafted neurons, providing strong evidence that transplanted human induced pluripotent stem cell-derived cortical neurons can become incorporated into injured cortical circuitry. Our findings support the idea that these neurons could contribute to functional recovery in stroke and other conditions causing neuronal loss in cerebral cortex. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email:

  10. Multisensory perceptual learning and sensory substitution.

    Proulx, Michael J; Brown, David J; Pasqualotto, Achille; Meijer, Peter


    One of the most exciting recent findings in neuroscience has been the capacity for neural plasticity in adult humans and animals. Studies of perceptual learning have provided key insights into the mechanisms of neural plasticity and the changes in functional neuroanatomy that it affords. Key questions in this field of research concern how practice of a task leads to specific or general improvement. Although much of this work has been carried out with a focus on a single sensory modality, primarily visual, there is increasing interest in multisensory perceptual learning. Here we will examine how advances in perceptual learning research both inform and can be informed by the development and advancement of sensory substitution devices for blind persons. To allow 'sight' to occur in the absence of visual input through the eyes, visual information can be transformed by a sensory substitution device into a representation that can be processed as sound or touch, and thus give one the potential to 'see' through the ears or tongue. Investigations of auditory, visual and multisensory perceptual learning can have key benefits for the advancement of sensory substitution, and the study of sensory deprivation and sensory substitution likewise will further the understanding of perceptual learning in general and the reverse hierarchy theory in particular. It also has significant importance for the developing understanding of the brain in metamodal terms, where functional brain areas might be best defined by the computations they carry out rather than by their sensory-specific processing role.

  11. Multiple microbial cell-free extracts improve the microbiological, biochemical and sensory features of ewes' milk cheese.

    Calasso, Maria; Mancini, Leonardo; De Angelis, Maria; Conte, Amalia; Costa, Cristina; Del Nobile, Matteo Alessandro; Gobbetti, Marco


    This study used cell-free enzyme (CFE) extracts from Lactobacillus casei, Hafnia alvei, Debaryomyces hansenii and Saccharomyces cerevisiae to condition or accelerate Pecorino-type cheese ripening. Compositional, microbiological, and biochemical analyses were performed, and volatile and sensory profiles were obtained. Lactobacilli and cocci increased during ripening, especially in cheeses containing CFE from L. casei, H. alvei and D. hansenii (LHD-C) and L. casei, H. alvei and S. cerevisiae (LHS-C). Compared to control cheese (CC), several enzymatic activities were higher (P CFE-supplemented cheeses. Compared to the CC (1907 mg kg(-1) of cheese), the free amino acid level increased (P CFE-supplemented cheeses, ranging from approximately 2575 (LHS-C) to 5720 (LHD-C) mg kg(-1) of cheese after 60 days of CFE-supplemented ripening. As shown by GC/MS analysis, the levels of several volatile organic compounds were significantly (P CFE-supplemented cheeses. All cheeses manufactured by adding multiple CFEs exhibited higher scores (P < 0.05) for internal structure, acid taste and juiciness than CC samples. This study shows the possibility of producing ewes' milk cheese with standardized characteristics and improved flavor intensity in a relatively short time. Copyright © 2017 Elsevier Ltd. All rights reserved.


    Vijin Ravindran Nambiar


    Full Text Available Objective: To study microbiology of external auditory canal in patients with itchy ears and to also study susceptibility profiles of pathogenic organisms to aid in appropriate management. Materials & Methods: A total of hundred patients were selected. An external ear canal swab was taken. For recovery of bacteria, the samples were emulsified in a solution of BHI broth to study aerobic and anaerobic bacteria. Fungal microbiology was studied by KOH mount and fungal culture. Culture and sensitivity was done for the pathogenic organisms. Results: Of the total hundred patients, 48% patients had no growth. There were no anaerobes isolated. Of the remaining 52% cases, 33% of the growth was aerobic bacteria and 19% of the growth was fungi. Of the aerobic bacteria, coagulase negative staphylococcus was isolated from 22 patients, staphylococcus aureus from 9 patients and pseudomonas aeruginosa from 2 patients. Of the fungal species, candida was isolated from 11 patients and aspergillus niger from 8 patients. Conclusion: Our study concluded that there need not be an underlying bacterial or fungal infection to cause itching as evidenced by a condition called asteatosis. Hence, asteatosis should be considered as one of the differential diagnosis for chronic and persistent itching when all other causes have been ruled out. We also found that topical ciprofloxacin drops is equally effective against the common bacterial pathogens.

  13. Inner ear tissue preservation by rapid freezing: improving fixation by high-pressure freezing and hybrid methods.

    Bullen, A; Taylor, R R; Kachar, B; Moores, C; Fleck, R A; Forge, A


    In the preservation of tissues in as 'close to life' state as possible, rapid freeze fixation has many benefits over conventional chemical fixation. One technique by which rapid freeze-fixation can be achieved, high pressure freezing (HPF), has been shown to enable ice crystal artefact-free freezing and tissue preservation to greater depths (more than 40 μm) than other quick-freezing methods. Despite increasingly becoming routine in electron microscopy, the use of HPF for the fixation of inner ear tissue has been limited. Assessment of the quality of preservation showed routine HPF techniques were suitable for preparation of inner ear tissues in a variety of species. Good preservation throughout the depth of sensory epithelia was achievable. Comparison to chemically fixed tissue indicated that fresh frozen preparations exhibited overall superior structural preservation of cells. However, HPF fixation caused characteristic artefacts in stereocilia that suggested poor quality freezing of the actin bundles. The hybrid technique of pre-fixation and high pressure freezing was shown to produce cellular preservation throughout the tissue, similar to that seen in HPF alone. Pre-fixation HPF produced consistent high quality preservation of stereociliary actin bundles. Optimising the preparation of samples with minimal artefact formation allows analysis of the links between ultrastructure and function in inner ear tissues. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Osteomas of the middle ear

    Sente Marko


    Full Text Available INTRODUCTION Osteomas of the middle ear are small, single, usually unilateral, peduncular growths, off-white in color, with smooth or multilobular surface, asymptomatic or causing functional disorders (progressive hearing loss, pathological appearance of the eardrum, vertigo and otorrhea, of unclear or unknown etiology. Fleury described three types of osteomas: massive, diffuse atticoantral and localized type. The therapy is surgical. Small and asymptomatic ones are followed-up. Cremers suggests surgical intervention in cases of progressive growth and increased hearing loss. Case description Discharge and pain in the left ear started twelve years ago, accompanied by impaired hearing and tinnitus. Four months ago the symptoms aggravated and discharge and pain increased. Otomicroscopic findings revealed: perforation in the posterior attic and a prominent polypous, clustered bright red formation. Schüller X-ray showed total absence of pneumocyte cells, with distinct sclerotic changes. Retroauricular access showed a biventricular bony formation in the cavum and partly in the antrum. A cholesteatoma extended from the cavum into the antrum, above the osteatoma. The bony formation was separated transmeatally from the grip in the posterior attic using a chisel, partially removing the bone wall of the exterior aural tube, removing it completely through the mastoid antrum. The removed bony mass, sized 5 x 8 x 8 mm, included also the incus. DISCUSSION Osteoma was discovered accidentally. Regarding clinical features, it belonged to the second group, due to progressive hearing loss, recurrent episodes of otorrhea, pain, biventricular shape and association with cholesteatoma. It was removed using a combined method. It was not possible to establish when the osteoma exactly started generating. It is possible that the initial complaints twelve years ago were the first signs of illness, and chronic otitis may have occurred as a consequence of the tumor.

  15. Immunohistochemical localization of two types of choline acetyltransferase in neurons and sensory cells of the octopus arm.

    Sakaue, Yuko; Bellier, Jean-Pierre; Kimura, Shin; D'Este, Loredana; Takeuchi, Yoshihiro; Kimura, Hiroshi


    Cholinergic structures in the arm of the cephalopod Octopus vulgaris were studied by immunohistochemistry using specific antisera for two types (common and peripheral) of acetylcholine synthetic enzyme choline acetyltransferase (ChAT): antiserum raised against the rat common type ChAT (cChAT), which is cross-reactive with molluscan cChAT, and antiserum raised against the rat peripheral type ChAT (pChAT), which has been used to delineate peripheral cholinergic structures in vertebrates, but not previously in invertebrates. Western blot analysis of octopus extracts revealed a single pChAT-positive band, suggesting that pChAT antiserum is cross-reactive with an octopus counterpart of rat pChAT. In immunohistochemistry, only neuronal structures of the octopus arm were stained by cChAT and pChAT antisera, although the pattern of distribution clearly differed between the two antisera. cChAT-positive varicose nerve fibers were observed in both the cerebrobrachial tract and neuropil of the axial nerve cord, while pChAT-positive varicose fibers were detected only in the neuropil of the axial nerve cord. After epitope retrieval, pChAT-positive neuronal cells and their processes became visible in all ganglia of the arm, including the axial and intramuscular nerve cords, and in ganglia of suckers. Moreover, pChAT-positive structures also became detectable in nerve fibers connecting the different ganglia, in smooth nerve fibers among muscle layers and dermal connective tissues, and in sensory cells of the suckers. These results suggest that the octopus arm has two types of cholinergic nerves: cChAT-positive nerves from brain ganglia and pChAT-positive nerves that are intrinsic to the arm.

  16. The plastic ear and perceptual relearning in auditory spatial perception.

    Simon eCarlile


    Full Text Available The auditory system of adult listeners has been shown to accommodate to altered spectral cues to sound location which presumably provides the basis for recalibration to changes in the shape of the ear over a life time. Here we review the role of auditory and non-auditory inputs to the perception of sound location and consider a range of recent experiments looking at the role of non-auditory inputs in the process of accommodation to these altered spectral cues. A number of studies have used small ear moulds to modify the spectral cues that result in significant degradation in localization performance. Following chronic exposure (10-60 days performance recovers to some extent and recent work has demonstrated that this occurs for both audio-visual and audio-only regions of space. This begs the questions as to the teacher signal for this remarkable functional plasticity in the adult nervous system. Following a brief review of influence of the motor state in auditory localisation, we consider the potential role of auditory-motor learning in the perceptual recalibration of the spectral cues. Several recent studies have considered how multi-modal and sensory-motor feedback might influence accommodation to altered spectral cues produced by ear moulds or through virtual auditory space stimulation using non-individualised spectral cues. The work with ear moulds demonstrates that a relatively short period of training involving sensory-motor feedback (5 – 10 days significantly improved both the rate and extent of accommodation to altered spectral cues. This has significant implications not only for the mechanisms by which this complex sensory information is encoded to provide a spatial code but also for adaptive training to altered auditory inputs. The review concludes by considering the implications for rehabilitative training with hearing aids and cochlear prosthesis.

  17. Mammalian Cochlear Hair Cell Regeneration and Ribbon Synapse Reformation

    Xiaoling Lu


    Full Text Available Hair cells (HCs are the sensory preceptor cells in the inner ear, which play an important role in hearing and balance. The HCs of organ of Corti are susceptible to noise, ototoxic drugs, and infections, thus resulting in permanent hearing loss. Recent approaches of HCs regeneration provide new directions for finding the treatment of sensor neural deafness. To have normal hearing function, the regenerated HCs must be reinnervated by nerve fibers and reform ribbon synapse with the dendrite of spiral ganglion neuron through nerve regeneration. In this review, we discuss the research progress in HC regeneration, the synaptic plasticity, and the reinnervation of new regenerated HCs in mammalian inner ear.

  18. The physics of hearing: fluid mechanics and the active process of the inner ear.

    Reichenbach, Tobias; Hudspeth, A J


    Most sounds of interest consist of complex, time-dependent admixtures of tones of diverse frequencies and variable amplitudes. To detect and process these signals, the ear employs a highly nonlinear, adaptive, real-time spectral analyzer: the cochlea. Sound excites vibration of the eardrum and the three miniscule bones of the middle ear, the last of which acts as a piston to initiate oscillatory pressure changes within the liquid-filled chambers of the cochlea. The basilar membrane, an elastic band spiraling along the cochlea between two of these chambers, responds to these pressures by conducting a largely independent traveling wave for each frequency component of the input. Because the basilar membrane is graded in mass and stiffness along its length, however, each traveling wave grows in magnitude and decreases in wavelength until it peaks at a specific, frequency-dependent position: low frequencies propagate to the cochlear apex, whereas high frequencies culminate at the base. The oscillations of the basilar membrane deflect hair bundles, the mechanically sensitive organelles of the ear's sensory receptors, the hair cells. As mechanically sensitive ion channels open and close, each hair cell responds with an electrical signal that is chemically transmitted to an afferent nerve fiber and thence into the brain. In addition to transducing mechanical inputs, hair cells amplify them by two means. Channel gating endows a hair bundle with negative stiffness, an instability that interacts with the motor protein myosin-1c to produce a mechanical amplifier and oscillator. Acting through the piezoelectric membrane protein prestin, electrical responses also cause outer hair cells to elongate and shorten, thus pumping energy into the basilar membrane's movements. The two forms of motility constitute an active process that amplifies mechanical inputs, sharpens frequency discrimination, and confers a compressive nonlinearity on responsiveness. These features arise because the

  19. The Postnatal Accumulation of Junctional E-cadherin Is Inversely Correlated with the Capacity for Supporting Cells to Convert Directly into Sensory Hair Cells in Mammalian Balance Organs

    Collado, Maria Sol; Thiede, Benjamin R.; Baker, Wendy; Askew, Charles; Igbani, Lisa M.; Corwin, Jeffrey T.


    Mammals experience permanent impairments from hair cell (HC) losses, but birds and other non-mammals quickly recover hearing and balance senses after supporting cells (SCs) give rise to replacement HCs. Avian HC epithelia express little or no E-cadherin, and differences in the thickness of F-actin belts at SC junctions strongly correlate with different species’ capacities for HC replacement, so we investigated junctional cadherins in human and murine ears. We found strong E-cadherin expression at SC-SC junctions that increases >6-fold postnatally in mice. When we cultured utricles from young mice with γ-secretase inhibitors (GSIs), striolar SCs completely internalized their E-cadherin, without affecting N-cadherin. Hes and Hey expression also decreased and the SCs began to express Atoh1. After 48 h, those SCs expressed myosins VI and VIIA, and by 72 h they developed hair bundles. However, some scattered striolar SCs retained E-cadherin and the SC phenotype. In extrastriolar regions the vast majority of SCs also retained E-cadherin and failed to convert into HCs even after long GSI treatments. Microscopic measurements revealed that the junctions between extrastriolar SCs were more developed than those between striolar SCs. In GSI-treated utricles as old as P12, differentiated striolar SCs converted into HCs, but such responses declined with age and ceased by P16. Thus, temporal and spatial differences in postnatal SC-to-HC phenotype conversion capacity are linked to the structural attributes of E-cadherin containing SC junctions in mammals, which differ substantially from their counterparts in non-mammalian vertebrates that readily recover from hearing and balance deficits through hair cell regeneration. PMID:21849546

  20. The postnatal accumulation of junctional E-cadherin is inversely correlated with the capacity for supporting cells to convert directly into sensory hair cells in mammalian balance organs.

    Collado, Maria Sol; Thiede, Benjamin R; Baker, Wendy; Askew, Charles; Igbani, Lisa M; Corwin, Jeffrey T


    Mammals experience permanent impairments from hair cell (HC) losses, but birds and other non-mammals quickly recover hearing and balance senses after supporting cells (SCs) give rise to replacement HCs. Avian HC epithelia express little or no E-cadherin, and differences in the thickness of F-actin belts at SC junctions strongly correlate with different species' capacities for HC replacement, so we investigated junctional cadherins in human and murine ears. We found strong E-cadherin expression at SC-SC junctions that increases more than sixfold postnatally in mice. When we cultured utricles from young mice with γ-secretase inhibitors (GSIs), striolar SCs completely internalized their E-cadherin, without affecting N-cadherin. Hes and Hey expression also decreased and the SCs began to express Atoh1. After 48 h, those SCs expressed myosins VI and VIIA, and by 72 h, they developed hair bundles. However, some scattered striolar SCs retained E-cadherin and the SC phenotype. In extrastriolar regions, the vast majority of SCs also retained E-cadherin and failed to convert into HCs even after long GSI treatments. Microscopic measurements revealed that the junctions between extrastriolar SCs were more developed than those between striolar SCs. In GSI-treated utricles as old as P12, differentiated striolar SCs converted into HCs, but such responses declined with age and ceased by P16. Thus, temporal and spatial differences in postnatal SC-to-HC phenotype conversion capacity are linked to the structural attributes of E-cadherin containing SC junctions in mammals, which differ substantially from their counterparts in non-mammalian vertebrates that readily recover from hearing and balance deficits through hair cell regeneration.

  1. Instabilities in sensory processes

    Balakrishnan, J.


    In any organism there are different kinds of sensory receptors for detecting the various, distinct stimuli through which its external environment may impinge upon it. These receptors convey these stimuli in different ways to an organism's information processing region enabling it to distinctly perceive the varied sensations and to respond to them. The behavior of cells and their response to stimuli may be captured through simple mathematical models employing regulatory feedback mechanisms. We argue that the sensory processes such as olfaction function optimally by operating in the close proximity of dynamical instabilities. In the case of coupled neurons, we point out that random disturbances and fluctuations can move their operating point close to certain dynamical instabilities triggering synchronous activity.

  2. Expression of macrophage migration inhibitory factor and CD74 in the inner ear and middle ear in lipopolysaccharide-induced otitis media.

    Ishihara, Hisashi; Kariya, Shin; Okano, Mitsuhiro; Zhao, Pengfei; Maeda, Yukihide; Nishizaki, Kazunori


    Significant expression of macrophage migration inhibitory factor and its receptor (CD74) was observed in both the middle ear and inner ear in experimental otitis media in mice. Modulation of macrophage migration inhibitory factor and its signaling pathway might be useful in the management of inner ear inflammation due to otitis media. Inner ear dysfunction secondary to otitis media has been reported. However, the specific mechanisms involved are not clearly understood. The aim of this study is to investigate the expression of macrophage migration inhibitory factor and CD74 in the middle ear and inner ear in lipopolysaccharide-induced otitis media. BALB/c mice received a transtympanic injection of either lipopolysaccharide or phosphate-buffered saline (PBS). The mice were sacrificed 24 h after injection, and temporal bones were processed for polymerase chain reaction (PCR) analysis, histologic examination, and immunohistochemistry. PCR examination revealed that the lipopolysaccharide-injected mice showed a significant up-regulation of macrophage migration inhibitory factor in both the middle ear and inner ear as compared with the PBS-injected control mice. The immunohistochemical study showed positive reactions for macrophage migration inhibitory factor and CD74 in infiltrating inflammatory cells, middle ear mucosa, and inner ear in the lipopolysaccharide-injected mice.

  3. Investigation of the ear-to-ear radio propagation channel

    Kvist, Søren Helstrup; Thaysen, J; Jakobsen, Kaj Bjarne


    The effect of the head size on the ear-to-ear radio propagation channel as a part of a body-centric wireless network is examined. The channel quality is evaluated at 2:45 GHz in terms of path gain (∣S21∣) between two monopole antennas that are placed normal to the surface of the head. The investi......The effect of the head size on the ear-to-ear radio propagation channel as a part of a body-centric wireless network is examined. The channel quality is evaluated at 2:45 GHz in terms of path gain (∣S21∣) between two monopole antennas that are placed normal to the surface of the head...

  4. Human ear recognition by computer

    Bhanu, Bir; Chen, Hui


    Biometrics deals with recognition of individuals based on their physiological or behavioral characteristics. The human ear is a new feature in biometrics that has several merits over the more common face, fingerprint and iris biometrics. Unlike the fingerprint and iris, it can be easily captured from a distance without a fully cooperative subject, although sometimes it may be hidden with hair, scarf and jewellery. Also, unlike a face, the ear is a relatively stable structure that does not change much with the age and facial expressions. ""Human Ear Recognition by Computer"" is the first book o

  5. Outcomes in Endoscopic Ear Surgery.

    Kiringoda, Ruwan; Kozin, Elliott D; Lee, Daniel J


    Endoscopic ear surgery (EES) provides several advantages compared with traditional binocular microscopy, including a wide-field view, improved resolution with high magnification, and visual access to hidden corridors of the middle ear. Although binocular microscopic-assisted surgical techniques remain the gold standard for most otologists, EES is slowly emerging as a viable alternative for performing otologic surgery at several centers in the United States and abroad. In this review, we evaluate the current body of literature regarding EES outcomes, summarize our EES outcomes at the Massachusetts Eye and Ear Infirmary, and compare these results with data for microscopic-assisted otologic surgery.

  6. Blastema Tissue Formed at Experimentally-Created Rabbit Ear Hole

    Mohamadreza Baghaban Eslaminejad


    Full Text Available   Objective(s: Throughout evolution, mammalians have increasingly lost their ability to regenerate structures however rabbits are exceptional since they develop a blastema in their ear wound for regeneration purposes. Blastema consists of a group of undifferentiated cells capable of dividing and differentiating into the ear tissue. The objective of the present study is to isolate, culture expand, and characterize blastema progenitor cells in terms of their in vitro differentiation capacity.   Materials and Methods: Five New Zealand white male rabbits were used in the present study. Using a punching apparatus, a 4-mm hole was created in the animal ears. Following 4 days, the blastema ring which was created in the periphery of primary hole in the ears was removed and cultivated. The cells migrated from the blastema were expanded through 3 successive subcultures and characterized in terms of their potential differentiation, growth characteristics, and culture requirements. Results: The primary cultures tended to be morphologically heterogeneous having spindly-shaped fibroblast-like cells as well as flattened cells. Fibroblast-like cells survived and dominated the cultures. These cells tended to have the osteogenic, chondrogenic, and adipogenic differentiation potentials. They were highly colonogenic and maximum proliferation was achieved when the cells were plated at density of 100 cells/cm2 in a medium which contained 10% fetal bovine serum (FBS. Conclusion: Taken together, blastema tissue-derived stem cells from rabbit ear are of mesenchymal stem cell-like population. Studies similar to this will assist scientist better understanding the nature of blastema tissue formed at rabbit ear to regenerate the wound.

  7. Metabotropic glutamate receptors are involved in the detection of IMP and L-amino acids by mouse taste sensory cells.

    Pal Choudhuri, S; Delay, R J; Delay, E R


    G-protein-coupled receptors are thought to be involved in the detection of umami and L-amino acid taste. These include the heterodimer taste receptor type 1 member 1 (T1r1)+taste receptor type 1 member 3 (T1r3), taste and brain variants of mGluR4 and mGluR1, and calcium sensors. While several studies suggest T1r1+T1r3 is a broadly tuned lLamino acid receptor, little is known about the function of metabotropic glutamate receptors (mGluRs) in L-amino acid taste transduction. Calcium imaging of isolated taste sensory cells (TSCs) of T1r3-GFP and T1r3 knock-out (T1r3 KO) mice was performed using the ratiometric dye Fura 2 AM to investigate the role of different mGluRs in detecting various L-amino acids and inosine 5' monophosphate (IMP). Using agonists selective for various mGluRs such as (RS)-3,5-dihydroxyphenylglycine (DHPG) (an mGluR1 agonist) and L-(+)-2-amino-4-phosphonobutyric acid (l-AP4) (an mGluR4 agonist), we evaluated TSCs to determine if they might respond to these agonists, IMP, and three L-amino acids (monopotassium L-glutamate, L-serine and L-arginine). Additionally, we used selective antagonists against different mGluRs such as (RS)-L-aminoindan-1,5-dicarboxylic acid (AIDA) (an mGluR1 antagonist), and (RS)-α-methylserine-O-phosphate (MSOP) (an mGluR4 antagonist) to determine if they can block responses elicited by these L-amino acids and IMP. We found that L-amino acid- and IMP-responsive cells also responded to each agonist. Antagonists for mGluR4 and mGluR1 significantly blocked the responses elicited by IMP and each of the L-amino acids. Collectively, these data provide evidence for the involvement of taste and brain variants of mGluR1 and mGluR4 in L-amino acid and IMP taste responses in mice, and support the concept that multiple receptors contribute to IMP and L-amino acid taste.

  8. Therapeutic potential of stem cells in auditory hair cell repair

    Ryuji Hata


    Full Text Available The prevalence of acquired hearing loss is very high. About 10% of the total population and more than one third of the population over 65 years suffer from debilitating hearing loss. The most common type of hearing loss in adults is idiopathic sudden sensorineural hearing loss (ISSHL. In the majority of cases, ISSHL is permanent and typically associated with loss of sensory hair cells in the organ of Corti. Following the loss of sensory hair cells, the auditory neurons undergo secondary degeneration. Sensory hair cells and auditory neurons do not regenerate throughout life, and loss of these cells is irreversible and cumulative. However, recent advances in stem cell biology have gained hope that stem cell therapy comes closer to regenerating sensory hair cells in humans. A major advance in the prospects for the use of stem cells to restore normal hearing comes with the recent discovery that hair cells can be generated ex vivo from embryonic stem (ES cells, adult inner ear stem cells and neural stem cells. Furthermore, there is increasing evidence that stem cells can promote damaged cell repair in part by secreting diffusible molecules such as growth factors. These results suggest that stem-cell-based treatment regimens can be applicable to the damaged inner ear as future clinical applications.Previously we have established an animal model of cochlear ischemia in gerbils and showed progressive hair cell loss up to 4 days after ischemia. Auditory brain stem response (ABR recordings have demonstrated that this gerbil model displays severe deafness just after cochlear ischemia and gradually recovers thereafter. These pathological findings and clinical manifestations are reminiscent of ISSHL in humans. In this study, we have shown the effectiveness of stem cell therapy by using this animal model of ISSHL.

  9. Global Ear. Werke 2001 - 2006


    Dresdenis muusikafestivalil "Global Ear" 23.3.03 esitusel Eesti heliloojate muusika: Helena Tulve "lumineux/opaque", Jaan Rääts "Meditation", Mirjam Tally "Aura", Mati Kuulberg "Sonate Nr.4", Mari Vihmand "Seitsmele"

  10. Global Ear. Werke 2001 - 2006


    Dresdenis muusikafestivalil "Global Ear" 23.3.03 esitusel Eesti heliloojate muusika: Helena Tulve "lumineux/opaque", Jaan Rääts "Meditation", Mirjam Tally "Aura", Mati Kuulberg "Sonate Nr.4", Mari Vihmand "Seitsmele"

  11. Multiple Osteomas in Middle Ear

    Yongxin Li


    Full Text Available Since the first description of middle ear osteomas by Thomas in 1964, only few reports were published within the English literatures (Greinwalid et al., 1998; Shimizu et al., 2003; Cho et al., 2005; and Jang et al., 2009, and only one case of the multiple osteomas in middle ear was described by Kim et al., 2006, which arose from the promontory, lateral semicircular canal, and epitympanum. Here we describe a patient with multiple middle ear osteomas arising from the promontory, incus, Eustachian tube, and bony semicanal of tensor tympani muscle. This patient also contracted the chronic otitis media in the ipsilateral ear. The osteomas were successfully removed by performing type III tympanoplasty in one stage.

  12. 21 CFR 870.2710 - Ear oximeter.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear oximeter. 870.2710 Section 870.2710 Food and... CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2710 Ear oximeter. (a) Identification. An ear... ear. The amount of reflected or scattered light as indicated by this device is used to measure...

  13. Long-term culture of utricular sensory epithelial cell of rats and expression of the hair cell characteristic markers%大鼠椭圆囊感觉上皮细胞长期培养体系的建立及毛细胞标记物表达的意义

    刘俊; 孔维佳


    目的:建立椭圆囊感觉上皮细胞(USEC)长期培养体系,为內耳毛细胞再生研究提供稳定的活性细胞.方法:取1 d龄wistar大鼠,在显微镜下取出椭圆囊上皮,嗜热菌蛋白酶处理,获得具活性的纯椭圆囊感觉上皮,胰蛋白酶+胶原酶消化,培养传代,传25代.取第25代USEC在倒置显微镜、透射电镜下对USEC的生长特征、形态结构进行观察;免疫细胞化学检测细胞角蛋白18、波形蛋白、Brn3.a 及Calretinin的表达.RT-PCR检测毛细胞的特征性标记物AchRa9、Myosin Ⅶa mRNA的表达.结果:USEC细胞培养达6个月传25代,第25代USEC均呈扁平、多角形、核大而圆的上皮细胞形态,细胞之间连接紧密,形成单层时均呈"铺路石样"外观,可见dome结构.该细胞表达角蛋白18和不表达波形蛋白,微绒毛丰富,细胞间连接紧密,提示其上皮起源.第25代USEC表达毛细胞的特征性标志物Brn3.a 、Calretinin及AchRa9、Myosin Ⅶa mRNA,表明长期培养USEC仍具有毛细胞的前体细胞的特性.结论:本实验成功建立了USEC长期培养体系.长期培养的USEC性状未发生明显改变,表达上皮细胞及毛细胞的特征性标志物,具有毛细胞前体细胞的特征.这为毛细胞再生的机制及内耳分子、基因研究提供了稳定的细胞来源.%Objective:To investigate the generative or regenerative hair cell and studes of molecular and genetic in the inner ear,the long-term culture systems of utricular sensory epithelial cell of the rats were established.Method:Utricular sensory epithelial of postnatal day 1 rats was isolated by mechanical dissociation.The explants were digested by thermolysin,then transfrred to an aliquot containing trypsin and collagenase for incubation to harvest the pure utricular sensory epithelial cell. USEC wes cultured in Dulbecco modified Eagle medium(DMEM) and passaged.USEC of the 25 passages observed by inverted microscope and ultrastrctural examination with transmission

  14. Better late than never: effective air-borne hearing of toads delayed by late maturation of the tympanic middle ear structures.

    Womack, Molly C; Christensen-Dalsgaard, Jakob; Hoke, Kim L


    Most vertebrates have evolved a tympanic middle ear that enables effective hearing of airborne sound on land. Although inner ears develop during the tadpole stages of toads, tympanic middle ear structures are not complete until months after metamorphosis, potentially limiting the sensitivity of post-metamorphic juveniles to sounds in their environment. We tested the hearing of five species of toads to determine how delayed ear development impairs airborne auditory sensitivity. We performed auditory brainstem recordings to test the hearing of the toads and used micro-computed tomography and histology to relate the development of ear structures to hearing ability. We found a large (14-27 dB) increase in hearing sensitivity from 900 to 2500 Hz over the course of ear development. Thickening of the tympanic annulus cartilage and full ossification of the middle ear bone are associated with increased hearing ability in the final stages of ear maturation. Thus, juvenile toads are at a hearing disadvantage, at least in the high-frequency range, throughout much of their development, because late-forming ear elements are critical to middle ear function at these frequencies. We discuss the potential fitness consequences of late hearing development, although research directly addressing selective pressures on hearing sensitivity across ontogeny is lacking. Given that most vertebrate sensory systems function very early in life, toad tympanic hearing may be a sensory development anomaly. © 2016. Published by The Company of Biologists Ltd.

  15. Schwann Cell Expressed Nogo-B Modulates Axonal Branching of Adult Sensory Neurons Through the Nogo-B Receptor NgBR.

    Eckharter, Christoph; Junker, Nina; Winter, Lilli; Fischer, Irmgard; Fogli, Barbara; Kistner, Steffen; Pfaller, Kristian; Zheng, Binhai; Wiche, Gerhard; Klimaschewski, Lars; Schweigreiter, Rüdiger


    In contrast to the central nervous system (CNS) nerve fibers do regenerate in the peripheral nervous system (PNS) although in a clinically unsatisfying manner. A major problem is excessive sprouting of regenerating axons which results in aberrant reinnervation of target tissue and impaired functional recovery. In the CNS, the reticulon protein Nogo-A has been identified as a prominent oligodendrocyte expressed inhibitor of long-distance growth of regenerating axons. We show here that the related isoform Nogo-B is abundantly expressed in Schwann cells in the PNS. Other than Nogo-A in oligodendrocytes, Nogo-B does not localize to the myelin sheath but is detected in the ER and the plasma membrane of Schwann cells. Adult sensory neurons that are cultured on nogo-a/b deficient Schwann cells form significantly fewer axonal branches vs. those on wildtype Schwann cells, while their maximal axonal extension is unaffected. We demonstrate that this effect of Nogo-B on neuronal morphology is restricted to undifferentiated Schwann cells and is mediated by direct physical contact between these two cell types. Moreover, we show that blocking the Nogo-B specific receptor NgBR, which we find expressed on sensory neurons and to interact with Schwann cell expressed Nogo-B, produces the same branching phenotype as observed after deletion of Nogo-B. These data provide evidence for a novel function of the nogo gene that is implemented by the Nogo-B isoform. The remarkably specific effects of Nogo-B/NgBR on axonal branching, while leaving axonal extension unaffected, are of potential clinical relevance in the context of excessive axonal sprouting after peripheral nerve injury. Nogo-B is prominently expressed in Schwann cells and localizes to the ER and plasma membrane. It distributes to the external cytoplasmic compartment of Schwann cells in vivo, but is absent from the myelin sheath.Genetic deletion of Nogo-B in Schwann cells reduces axonal branching, but not long-distance growth, of

  16. Revised lineage of larval photoreceptor cells in Ciona reveals archetypal collaboration between neural tube and neural crest in sensory organ formation.

    Oonuma, Kouhei; Tanaka, Moeko; Nishitsuji, Koki; Kato, Yumiko; Shimai, Kotaro; Kusakabe, Takehiro G


    The Ciona intestinalis larva has two distinct photoreceptor organs, a conventional pigmented ocellus and a nonpigmented ocellus, that are asymmetrically situated in the brain. The ciliary photoreceptor cells of these ocelli resemble visual cells of the vertebrate retina. Precise elucidation of the lineage of the photoreceptor cells will be key to understanding the developmental mechanisms of these cells as well as the evolutionary relationships between the photoreceptor organs of ascidians and vertebrates. Photoreceptor cells of the pigmented ocellus have been thought to develop from anterior animal (a-lineage) blastomeres, whereas the developmental origin of the nonpigmented ocellus has not been determined. Here, we show that the photoreceptor cells of both ocelli develop from the right anterior vegetal hemisphere: those of the pigmented ocellus from the right A9.14 cell and those of the nonpigmented ocellus from the right A9.16 cell. The pigmented ocellus is formed by a combination of two lineages of cells with distinct embryonic origins: the photoreceptor cells originate from a medial portion of the A-lineage neural plate, while the pigment cell originates from the lateral edge of the a-lineage neural plate. In light of the recently proposed close evolutionary relationship between the ocellus pigment cell of ascidians and the cephalic neural crest of vertebrates, the ascidian ocellus may represent a prototypic contribution of the neural crest to a cranial sensory organ.

  17. The plastic ear and perceptual relearning in auditory spatial perception.

    Carlile, Simon


    The auditory system of adult listeners has been shown to accommodate to altered spectral cues to sound location which presumably provides the basis for recalibration to changes in the shape of the ear over a life time. Here we review the role of auditory and non-auditory inputs to the perception of sound location and consider a range of recent experiments looking at the role of non-auditory inputs in the process of accommodation to these altered spectral cues. A number of studies have used small ear molds to modify the spectral cues that result in significant degradation in localization performance. Following chronic exposure (10-60 days) performance recovers to some extent and recent work has demonstrated that this occurs for both audio-visual and audio-only regions of space. This begs the questions as to the teacher signal for this remarkable functional plasticity in the adult nervous system. Following a brief review of influence of the motor state in auditory localization, we consider the potential role of auditory-motor learning in the perceptual recalibration of the spectral cues. Several recent studies have considered how multi-modal and sensory-motor feedback might influence accommodation to altered spectral cues produced by ear molds or through virtual auditory space stimulation using non-individualized spectral cues. The work with ear molds demonstrates that a relatively short period of training involving audio-motor feedback (5-10 days) significantly improved both the rate and extent of accommodation to altered spectral cues. This has significant implications not only for the mechanisms by which this complex sensory information is encoded to provide spatial cues but also for adaptive training to altered auditory inputs. The review concludes by considering the implications for rehabilitative training with hearing aids and cochlear prosthesis.

  18. 内耳注入携带 IL -4基因的骨髓间充质干细胞对豚鼠免疫性内耳病基因治疗的研究%Gene Therapy of Inner Ear Injection with Bone -Marrow Mesenchymal Stem Cells Decorated with Interleukin-4 Gene on Immune-Mediated Inner Ear Disease in Guinea Pigs

    郭浪; 谭长强; 刘树森; 江萍; 衡伟伟


    目的:研究内耳局部植入白细胞介素4(IL -4)基因修饰骨髓间充质干细胞(bone-marrow mesen-chymal stem cells ,BMSCs)对免疫性内耳病豚鼠内耳病理损伤和听功能的调节与治疗作用。方法采用钥孔嘁血蓝蛋白(KLH)抗原在已致敏的豚鼠圆窗龛局部免疫,制成豚鼠免疫性内耳病模型55只,分为五组:A组(BMSCs载体组)、B组(BM SCs空载体对照组)、C组(重组慢病毒IL -4基因组)、D组(慢病毒空载体对照组)及E组(模拟手术对照组),每组11只,各组均将相应的悬液20μl[BMSCs悬液中含BMSCs(1.5~2.0)×106,慢病毒浓缩液浓度为0.5×108 pfu]经鼓阶开窗植入内耳。采用免疫荧光组织化学试验法、免疫酶组织化学试验法观察IL -4基因产物在内耳组织结构中的分布和表达情况,酶联免疫吸附试验观察血清抗KLH特异性抗体水平,ABR测试听功能变化。结果与免疫前相比,免疫后A、B、C组ABR波Ⅲ阈值不同程度降低,A组阈值降低更明显,差异有统计学意义(P<0.05);免疫组织化学染色显示BMSCs荧光反应阳性细胞主要分布在鼓阶、前庭阶;内耳光镜观察A、B、C组仅在鼓阶内有絮状物,注射部位有少量红细胞和白细胞,D、E组可见不同程度的膜迷路积水,螺旋神经节和蜗轴小血管周围有单个核细胞浸润。结论重组IL -4基因的慢病毒载体可在体外成功转染BM SCs ,经鼓阶途径植入内耳后可在内耳迁移并产生基因产物IL -4,可明显减轻免疫性内耳病动物的内耳免疫炎性反应和听功能损伤,而BMSCs可以作为细胞载体把携带有目的基因的治疗因子迁移到损伤部位而发挥治疗作用。%Objective To evaluate the gene therapeutic effects of guinea pigs model with immune -mediated inner ear disease(IMIED)after locally injection of bone -marrow mesenchymal stem cells(BMSCs) decorated by in

  19. Anti-inflammatory effect of tricin 4′-O-(threo-β-guaiacylglyceryl) ether, a novel flavonolignan compound isolated from Njavara on in RAW264.7 cells and in ear mice edema

    Jung, Young-Suk [College of Pharmacy, Pusan National University, Busan 609-735 (Korea, Republic of); Kim, Dae Hwan; Hwang, Jae Yeon; Yun, Na Young [College of Pharmacy and Medical Research Center, Chungbuk National University, Chungbuk 361-763 (Korea, Republic of); Lee, Yun-Hee [Department of Pathology, Wayne State University School of Medicine, Detroit, MI 48201 (United States); Han, Sang Bae; Hwang, Bang Yeon [College of Pharmacy and Medical Research Center, Chungbuk National University, Chungbuk 361-763 (Korea, Republic of); Lee, Moon Soon [College of Agriculture, Life and Environments, Chungbuk National University, Chungbuk 361-763 (Korea, Republic of); Jeong, Heon-Sang [Department of Food Science and Technology, Chungbuk National University, Chungbuk 361-763 (Korea, Republic of); Hong, Jin Tae, E-mail: [College of Pharmacy and Medical Research Center, Chungbuk National University, Chungbuk 361-763 (Korea, Republic of)


    Although recent study has shown tricin 4′-O-(threo-β-guaiacylglyceryl) ether (TTGE), an isolated compound from Njavara rice, to have the most potent anti-inflammatory effects, the action mechanism has not been fully understood. Here, we examined the effect of TTGE on the inflammation and elucidated the potential mechanism. We demonstrated that TTGE significantly inhibited LPS-induced NO and ROS generation in RAW264.7 cells, which was correlated with the down-regulating effect of TTGE on the iNOS and COX-2 expression via NF-κB and STAT3. TPA-induced ear edema was also efficiently inhibited by the TTGE treatment. TTGE blocked the induction of iNOS and COX-2 through the regulation of NF-κB and STAT3, which could explain the reduced TPA-induced edema symptoms. Moreover, the introduction of ERK inhibitor abrogated the anti-inflammatory effect of TTGE via the recovery of NF-κB and STAT3 signalings. Taken together, these results suggest that TTGE has anti-inflammatory properties through down-regulation of NF-κB and STAT3 pathways. - Highlights: • TTGE inhibited expression of iNOS and COX-2, NF-kB activity and ear edema through inhibition of ERK pathway.

  20. IgSF8: a developmentally and functionally regulated cell adhesion molecule in olfactory sensory neuron axons and synapses

    Ray, Arundhati; Treloar, Helen B.


    Here, we investigated an Immunoglobulin (Ig) superfamily protein IgSF8 which is abundantly expressed in olfactory sensory neuron (OSN) axons and their developing synapses. We demonstrate that expression of IgSF8 within synaptic neuropil is transitory, limited to the period of glomerular formation. Glomerular expression decreases after synaptic maturation and compartmental glomerular organization is achieved, although expression is maintained at high levels within the olfactory nerve layer (ON...

  1. Schwann cell expressed Nogo-B modulates axonal branching of adult sensory neurons through the Nogo-B receptor NgBR

    Christoph eEckharter


    Full Text Available In contrast to the central nervous system (CNS nerve fibers do regenerate in the peripheral nervous system (PNS although in a clinically unsatisfying manner. A major problem is excessive sprouting of regenerating axons which results in aberrant reinnervation of target tissue and impaired functional recovery. In the CNS, the reticulon protein Nogo-A has been identified as a prominent oligodendrocyte expressed inhibitor of long-distance growth of regenerating axons. We show here that the related isoform Nogo-B is abundantly expressed in Schwann cells in the PNS. Other than Nogo-A in oligodendrocytes, Nogo-B does not localize to the myelin sheath but is detected in the ER and the plasma membrane of Schwann cells. Adult sensory neurons that are cultured on nogo-a/b deficient Schwann cells form significantly fewer axonal branches versus those on wildtype Schwann cells, while their maximal axonal extension is unaffected. We demonstrate that this effect of Nogo-B on neuronal morphology is restricted to undifferentiated Schwann cells and is mediated by direct physical contact between these two cell types. Moreover, we show that blocking the Nogo-B specific receptor NgBR, which we find expressed on sensory neurons and to interact with Schwann cell expressed Nogo-B, produces the same branching phenotype as observed after deletion of Nogo-B. These data provide evidence for a novel function of the nogo gene that is implemented by the Nogo-B isoform. The remarkably specific effects of Nogo-B/ NgBR on axonal branching, while leaving axonal extension unaffected, are of potential clinical relevance in the context of excessive axonal sprouting after peripheral nerve injury.

  2. Ear surgery techniques results on hearing threshold improvement

    Farhad Mokhtarinejad


    Full Text Available Background: Bone conduction (BC threshold depression is not always by means of sensory neural hearing loss and sometimes it is an artifact caused by middle ear pathologies and ossicular chain problems. In this research, the influences of ear surgeries on bone conduction were evaluated. Materials and Methods: This study was conducted as a clinical trial study. The ear surgery performed on 83 patients classified in four categories: Stapedectomy, tympanomastoid surgery and ossicular reconstruction partially or totally; Partial Ossicular Replacement Prosthesis (PORP and Total Ossicular Replacement Prosthesis (TORP. Bone conduction thresholds assessed in frequencies of 250, 500, 1000, 2000 and 4000 Hz pre and post the surgery. Results: In stapedectomy group, the average of BC threshold in all frequencies improved approximately 6 dB in frequency of 2000 Hz. In tympanomastoid group, BC threshold in the frequency of 500, 1000 and 2000 Hz changed 4 dB (P-value < 0.05. Moreover, In the PORP group, 5 dB enhancement was seen in 1000 and 2000 Hz. In TORP group, the results confirmed that BC threshold improved in all frequencies especially at 4000 Hz about 6.5 dB. Conclusion: In according to results of this study, BC threshold shift was seen after several ear surgeries such as stapedectomy, tympanoplasty, PORP and TORP. The average of BC improvement was approximately 5 dB. It must be considered that BC depression might happen because of ossicular chain problems. Therefore; by resolving middle ear pathologies, the better BC threshold was obtained, the less hearing problems would be faced.

  3. Effect of Binghuang ear drop treatment on otitis externa in guinea pigs.

    Zhai, Suo-qiang; Yu, Ning; Guo, Wei-Wei; Zhang, Yue


    To investigate the pharmacodynamic effects of Binghuang ear drop on acute suppurative otitis externa in guinea pig model. Thirty guinea pigs were randomly divided into three groups, with ten animals in each group. Group A animals had normal ear canal and Binghuang ear drops (two drops, B.I.D) were applied in both ears for 7 days; Group B animals had induced otitis externa and received identical prescription as group A; Group C had normal ear canal and were treated with normal saline (two drops, B.I.D) for 7 days. After the treatments, the external morphology of ear canals was observed and the paraffin sections of external auditory canal were prepared and examined under the microscope. The inflammatory manifestation and cell infiltration into the skin of group B was significantly attenuated after the Binghuang ear drops treatment. In contrast, no allergy or side effects were produced by Binghuang ear drops application in the animals with normal ear canals. Binghuang ear drops could be used to treat acute otitis externa by eliciting anti-bacterial effects.

  4. Ear Disorders in Scuba Divers

    MH Azizi


    Full Text Available History of underwater diving dates back to antiquity. Breath-hold technique in diving was known to the ancient nations. However, deep diving progressed only in the early decades of the 19th century as the result of advancements in efficient underwater technologies which subsequently led to invention of sophisticated sets of scuba diving in the 20th century. Currently, diving is performed for various purposes including commercial, recreational, military, underwater construction, oil industry, underwater archeology and scientific assessment of marine life. By increasing popularity of underwater diving, dive-related medical conditions gradually became more evident and created a new challenge for the health care professionals, so that eventually, a specialty the so-called “diving medicine” was established. Most of the diving-associated disorders appear in the head and neck. The most common of all occupational disorders associated with diving are otologic diseases. External otitis has been reported as the most common otolaryngologic problem in underwater divers. Exostosis of the external ear canal may be formed in divers as the result of prolonged diving in cold waters. Other disorders of the ear and paranasal sinuses in underwater divers are caused by barometric pressure change (i.e., barotraumas, and to a lesser extent by decompression sickness. Barotrauma of the middle ear is the most prevalent barotrauma in divers. The inner ear barotraumas, though important, is less common. The present paper is a brief overview of diving-related ear disorders particularly in scuba divers.

  5. 3D finite element model of the chinchilla ear for characterizing middle ear functions.

    Wang, Xuelin; Gan, Rong Z


    Chinchilla is a commonly used animal model for research of sound transmission through the ear. Experimental measurements of the middle ear transfer function in chinchillas have shown that the middle ear cavity greatly affects the tympanic membrane (TM) and stapes footplate (FP) displacements. However, there is no finite element (FE) model of the chinchilla ear available in the literature to characterize the middle ear functions with the anatomical features of the chinchilla ear. This paper reports a recently completed 3D FE model of the chinchilla ear based on X-ray micro-computed tomography images of a chinchilla bulla. The model consisted of the ear canal, TM, middle ear ossicles and suspensory ligaments, and the middle ear cavity. Two boundary conditions of the middle ear cavity wall were simulated in the model as the rigid structure and the partially flexible surface, and the acoustic-mechanical coupled analysis was conducted with these two conditions to characterize the middle ear function. The model results were compared with experimental measurements reported in the literature including the TM and FP displacements and the middle ear input admittance in chinchilla ear. An application of this model was presented to identify the acoustic role of the middle ear septa-a unique feature of chinchilla middle ear cavity. This study provides the first 3D FE model of the chinchilla ear for characterizing the middle ear functions through the acoustic-mechanical coupled FE analysis.

  6. Glia Are Essential for Sensory Organ Function in C. elegans

    Bacaj, Taulant; Tevlin, Maya; Lu, Yun; Shaham, Shai


    Sensory organs are composed of neurons, which convert environmental stimuli to electrical signals, and glia-like cells, whose functions are not well-understood. To decipher glial roles in sensory organs, we ablated the sheath glial cell of the major sensory organ of Caenorhabditis elegans. We found that glia-ablated animals exhibit profound sensory deficits and that glia provide activities that affect neuronal morphology, behavior generation, and neuronal uptake of lipophilic dyes. To underst...

  7. Applications of scanning electron microscopy and X-ray microanalysis in inner ear pathology

    Anniko, M.; Lim, D.J.; Sobin, A.; Wroblewski, R.


    Surface pathology of inner ear structures so far described in detail concern cochlear and vestibular hair cells and the stria vascularis. In man, surgical intervention into the inner ear is very uncommon and when performed is in general with the primary objective of destroying the diseased peripheral end organs. The vast majority of inner ear tissue available for use with scanning electron microscopy (SEM) is therefore obtained from animals. The present paper reviews the progression of surface pathology caused by aminoglycoside antibiotics, acoustic overstimulation and in a guinea pig strain with genetic inner ear disease. The primary site of onset of surface pathology differs, depending on the underlying cause. Advanced surface pathology shows a similar type of morphological degeneration independent of cause. The combination of SEM and energy dispersive X-ray microanalysis (XRMA) of inner ear pathology has as yet been reported in only three studies, all concerning inner ear fluids or otoconia.

  8. Diversity of Inner Ears in Fishes: Possible Contribution Towards Hearing Improvements and Evolutionary Considerations.

    Schulz-Mirbach, Tanja; Ladich, Friedrich


    Fishes have evolved the largest diversity of inner ears among vertebrates. While G. Retzius introduced us to the diversity of the gross morphology of fish ears in the late nineteenth century, it was A. N. Popper who unraveled the large variety of the fine structure during the last four decades. Modifications of the basic inner ear structure-consisting of three semicircular canals and their sensory epithelia, the cristae and three otolithic end organs (utricle, saccule, lagena) including the maculae-mainly relate to the saccule and lagena and the respective sensory epithelia, the macula sacculi and macula lagenae. Despite the profound morphological knowledge of inner ears and the morphological variability, the functional significance of this diversity is still largely unknown. The aims of this review are therefore twofold. First it provides an update of the state of the art of inner ear diversity in bony fishes. Second it summarizes and discusses hypotheses on the evolution of this diversity as well as formulates open questions and promising approaches to tackle these issues.

  9. Cochlear gene therapy with ancestral AAV in adult mice: complete transduction of inner hair cells without cochlear dysfunction

    Suzuki, Jun; Hashimoto, Ken; Xiao, Ru; Vandenberghe, Luk H.; Liberman, M. Charles


    The use of viral vectors for inner ear gene therapy is receiving increased attention for treatment of genetic hearing disorders. Most animal studies to date have injected viral suspensions into neonatal ears, via the round window membrane. Achieving transduction of hair cells, or sensory neurons, throughout the cochlea has proven difficult, and no studies have been able to efficiently transduce sensory cells in adult ears while maintaining normal cochlear function. Here, we show, for the first time, successful transduction of all inner hair cells and the majority of outer hair cells in an adult cochlea via virus injection into the posterior semicircular canal. We used a “designer” AAV, AAV2/Anc80L65, in which the main capsid proteins approximate the ancestral sequence state of AAV1, 2, 8, and 9. Our injections also transduced ~10% of spiral ganglion cells and a much larger fraction of their satellite cells. In the vestibular sensory epithelia, the virus transduced large numbers of hair cells and virtually all the supporting cells, along with close to half of the vestibular ganglion cells. We conclude that this viral vector and this delivery route hold great promise for gene therapy applications in both cochlear and vestibular sense organs. PMID:28367981

  10. Does improved hearing result in altered inner ear morphology?

    Tanja Schulz-Mirbach


    Full Text Available The sense of hearing plays an important role for fishes to obtain information about their (acoustic environment (e.g. Popper 2011, Fay 2011. In numerous taxa, ancillary auditory structures like swimbladder modifications evolved, leading to an improved audition (Braun and Grande 2008. Despite a profound knowledge of inner ear diversity and ancillary auditory structures (for an overview see Schulz-Mirbach and Ladich 2015, Ladich 2015, the relationship between the morphology of these structures and hearing abilities remains to be elucidated. We tested the hypothesis that swimbladder modifications coincide with differences in inner ear morphology, using cichlids as a model because they show considerable intrafamilial diversity in swimbladder morphology and hearing capabilities (Schulz-Mirbach et al. 2012, 2014. We compared Steatocranus tinanti (vestigial swimbladder, Hemichromis guttatus (large swimbladder without extensions, and Etroplus maculatus (intimate connection between swimbladder and inner ears by applying immunostaining together with confocal imaging for the investigation of sensory epithelia, and high-resolution, contrast enhanced microCT imaging for characterizing inner ears in 3D. Compared to S. tinanti and H. guttatus, inner ears of E. maculatus showed an enlargement of all three maculae, and a particularly large lacinia of the macula utriculi. While our analysis of orientation patterns of ciliary bundles on the three macula types using artificially flattened maculae uncovered rather similar orientation patterns of ciliary bundles, interspecific differences became apparent when illustrating the orientation patterns on the 3D models of the maculae: differences in the shape and curvature of the lacinia of the macula utriculi, and the anterior arm of the macula lagenae resulted in an altered arrangement of ciliary bundles. Our results imply that improved hearing in E. maculatus is associated not only with swimbladder modifications but

  11. Investigation of the ear-to-ear radio propagation channel

    Kvist, Søren Helstrup; Thaysen, J; Jakobsen, Kaj Bjarne


    The effect of the head size on the ear-to-ear radio propagation channel as a part of a body-centric wireless network is examined. The channel quality is evaluated at 2:45 GHz in terms of path gain (∣S21∣) between two monopole antennas that are placed normal to the surface of the head. The investi......The effect of the head size on the ear-to-ear radio propagation channel as a part of a body-centric wireless network is examined. The channel quality is evaluated at 2:45 GHz in terms of path gain (∣S21∣) between two monopole antennas that are placed normal to the surface of the head....... The investigation is done by SAM head phantom measurements and HFSS simulations. The investigations include setups where some propagation paths are blocked by an absorbing material. It is found that the characteristics of the head may cause constructive or destructive interference that may result in up to 10 d...

  12. Classification and diagnosis of ear malformations

    Bartel-Friedrich, Sylva


    Full Text Available In the ENT region 50% of the malformations affect the ear. Malformations of the outer and middle ear are predominantly unilateral (ca. 70-90% and mostly involve the right ear. Inner ear malformations can be unilateral or bilateral. The incidence of ear malformations is approximately 1 in 3800 newborns. Ear malformations may be genetic (associated with syndromes or not, with family history, spontaneous mutations or acquired in nature. Malformations can affect the outer ear (pinna and external auditory canal, EAC, middle ear and inner ear, not infrequently in combination. Formal classification is advisable in order to be able to predict the prognosis and compare treatment schedules. Various classifications have been proposed: pinna and EAC malformations according to Weerda [1], middle ear malformations according to Kösling [2], and inner ear malformations according to Jackler [3], [4], to Marangos [5] and to Sennaroglu [6]. Additionally, we describe Altmann’s classification of atresia auris congenita [7] and the Siegert-Mayer-Weerda score [8] for EAC and middle ear malformations, systems of great practicability that are in widespread clinical use. The diagnostic steps include clinical examination, audiological testing, genetic analysis and, especially, CT and MRI. These imaging methods are most usefully employed in combination. Precise description of the malformations by means of CT and MRI is indispensable for the planning and successful outcome of operative ear reconstruction and rehabilitation procedures, including cochlear implantation.

  13. Expression of PINK1 in the brain, eye and ear of mouse during embryonic development.

    d'Amora, Marta; Angelini, Cristiano; Marcoli, Manuela; Cervetto, Chiara; Kitada, Tohru; Vallarino, Mauro


    PINK1 is a 581 amino acid protein with a serine/threonine kinase domain and an N-terminal mitochondrial targeting motif. The enzyme is expressed in the brain as well as in several tissues such as heart, skeletal muscle, liver, kidney, pancreas and testis. In the present study, we have investigated by Western blot analysis and immunohistochemistry the presence and distribution of PINK1 in the brain, eye and inner ear of mouse during embryonic development. In the brain we detected two PINK1 molecular isoforms of 55 kDa and 66 kDa. Immunoreactive perikarya first appeared at stage E15 in the diencephalon within the thalamus, the hypothalamus, the periventricular layers of the third ventricle and in the rhombencephalon at level of the pons. Subsequently, new PINK1-positive neurons were found in the midbrain within the floor and the periventricular layers of the ventral wall of the mesencephalic vesicle (stage E17) as well as in the neopallial cortex, the tegmentum of the midbrain and the periventricular region of the caudal part of the rhombencephalon (stage E19). At P0, PINK1-immunoreactive cells appeared in the striatum, the mantle layer and caudal part of the medulla oblongata and the cerebellum. The spatio-temporal expression of PINK1 and its heterogeneous distribution suggest that the enzyme might be involved in neuroregulatory processes during embryogenesis. In the eye, PINK1-immunoreactivity was found in the lens and in the cornea, whereas in the inner ear the enzyme was expressed in the ependymal and subependymal cells of the saccule and in the semicircular canals indicating that PINK1 plays a role in the development of these sensory organs. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. In vivo whole-cell patch-clamp recording of sensory synaptic responses of cingulate pyramidal neurons to noxious mechanical stimuli in adult mice

    Descalzi Giannina


    Full Text Available Abstract The anterior cingulate cortex (ACC plays important roles in emotion, learning, memory and persistent pain. Our previous in vitro studies have demonstrated that pyramidal neurons in layer II/III of the adult mouse ACC can be characterized into three types: regular spiking (RS, intermediate (IM and intrinsic bursting (IB cells, according to their action potential (AP firing patterns. However, no in vivo information is available for the intrinsic properties and sensory responses of ACC neurons of adult mice. Here, we performed in vivo whole-cell patch-clamp recordings from pyramidal neurons in adult mice ACC under urethane anesthetized conditions. First, we classified the intrinsic properties and analyzed their slow oscillations. The population ratios of RS, IM and IB cells were 10, 62 and 28%, respectively. The mean spontaneous APs frequency of IB cells was significantly greater than those of RS and IM cells, while the slow oscillations were similar among ACC neurons. Peripheral noxious pinch stimuli induced evoked spike responses in all three types of ACC neurons. Interestingly, IB cells showed significantly greater firing frequencies than RS and IM cells. In contrast, non-noxious brush did not induce any significant response. Our studies provide the first in vivo characterization of ACC neurons in adult mice, and demonstrate that ACC neurons are indeed nociceptive. These findings support the critical roles of ACC in nociception, from mice to humans.

  15. Interconnections between the Ears in Nonmammalian Vertebrates

    Feng, Albert S.; Christensen-Dalsgaard, J.


    Many of the nonmammalian vertebrates (anurans, lizards, crocodiles, and some bird species) have large, continuous air spaces connecting the middle ears and acoustically coupling the eardrums. Acoustical coupling leads to strongly enhanced directionality of the ear at frequencies where diffraction...

  16. Middle ear infection (otitis media) (image)

    Otitis media is an inflammation or infection of the middle ear. Acute otitis media (acute ear infection) occurs when there is ... which causes production of fluid or pus. Chronic otitis media occurs when the eustachian tube becomes blocked ...


    Yaşar KARAGÖZ


    Full Text Available Plough is an agricultural tool which is used for preparing land to male it ready for sowing. The funotion of lough is to break the compact land into small pieces and to allow a suitable condition for living of culture plants. The ear is the most important part of active plough surface. The geometrical form of ear determines the form of active surface together with the front iron tip. Ploughs are divided into two categories which are European and American types. There are important differencies betucen the European and American tyges with respect to ?, ß and ? angles. Gorjatschkin described the ear form of European ploughs under four main groups which are: 1. Cylindirical ear type, 2. Culture-form ear type, 3. Semi-curled ear type, 4. Curled ear type. In this work, the designing of cylindirical ear was studied.

  18. Report sensory analyses veal

    Veldman, M.; Schelvis-Smit, A.A.M.


    On behalf of a client of Animal Sciences Group, different varieties of veal were analyzed by both instrumental and sensory analyses. The sensory evaluation was performed with a sensory analytical panel in the period of 13th of May and 31st of May, 2005. The three varieties of veal were: young bull,

  19. Tympanoplasty without use of gelfoam in the middle ear

    Samad Ghiasi


    Full Text Available Introduction:  In usual technique of tympanoplasty almost all of otologic surgeons use gelfoam in the middle ear for support of graft against margin of tympanic membrane perforation. In this study we use technique that we did not use gelfoam in the middle ear. We compared results of graft taking rate in two techniques. Materials and Methods: In a clinical trial study during 2 years 181 patients with COM underwent tympanoplasty with underlay grafting. In 83 patients used gelfoam in the middle ear for tympanoplasty or tympanomastoidectomy (CCTM, OCTM. In 98 patients we did not use gelfoam in the middle ear. Results: In 83 patients with use of gelfoam, graft taking rate in 59 (71.1% cases with tympanoplasty and CCTM was 54 (91% and in 24 (28.9% cases with OCTM was 20 (83%. In 98 patients without use of gelfoam, graft taking rate in 61 (62.2% cases with tympanoplasty and CCTM was 54 (89% and in 37 (37.8% cases with OCTM were 31 (84%. Conclusion: In this study, results of graft taking rate were similar in 2 groups. On the other hand, gelfoam entirely reabsorbed during 45 to 54 days in the middle ear and immune system react by a round cell response. This sponge encourages the formation of the fibrous tissue at a higher rate than naturally occurs in the ear. In our technique we had not these problems. Another advantage of this technique is rapid improvement of patient hearing after removing of the external ear canal rosebud. We think this technique could be used in tympanoplasty and tympanomastoidectoy routinely. ‍‍‍



    April 2004 Vol.22 No.4 CME. 193. KAREN COHEN. MB ChB ... the ear canal and they are usually in the 40 - 50-year age group. ... Treatment. The treatment of choice is intravenous antibiotics consisting of aminoglyco- side, piperacillin and ...

  1. Adult human nasal mesenchymal-like stem cells restore cochlear spiral ganglion neurons after experimental lesion.

    Bas, Esperanza; Van De Water, Thomas R; Lumbreras, Vicente; Rajguru, Suhrud; Goss, Garrett; Hare, Joshua M; Goldstein, Bradley J


    A loss of sensory hair cells or spiral ganglion neurons from the inner ear causes deafness, affecting millions of people. Currently, there is no effective therapy to repair the inner ear sensory structures in humans. Cochlear implantation can restore input, but only if auditory neurons remain intact. Efforts to develop stem cell-based treatments for deafness have demonstrated progress, most notably utilizing embryonic-derived cells. In an effort to bypass limitations of embryonic or induced pluripotent stem cells that may impede the translation to clinical applications, we sought to utilize an alternative cell source. Here, we show that adult human mesenchymal-like stem cells (MSCs) obtained from nasal tissue can repair spiral ganglion loss in experimentally lesioned cochlear cultures from neonatal rats. Stem cells engraft into gentamicin-lesioned organotypic cultures and orchestrate the restoration of the spiral ganglion neuronal population, involving both direct neuronal differentiation and secondary effects on endogenous cells. As a physiologic assay, nasal MSC-derived cells engrafted into lesioned spiral ganglia demonstrate responses to infrared laser stimulus that are consistent with those typical of excitable cells. The addition of a pharmacologic activator of the canonical Wnt/β-catenin pathway concurrent with stem cell treatment promoted robust neuronal differentiation. The availability of an effective adult autologous cell source for inner ear tissue repair should contribute to efforts to translate cell-based strategies to the clinic.

  2. Inner ear of the coelacanth fish Latimeria has tetrapod affinities.

    Fritzsch, B

    Auditory reception in elasmobranchs, teleosts and amphibians may be mediated by various inner-ear sensory epithelia 1–3, including the basilar papilla, which seems to be the precursor of the cochlea in mammals. The origin of the basilar papilla remains a major unsolved problem for understanding the evolution of hearing in terrestrial vertebrates4–6. Study of living species indicates that the basilar papilla is a unique feature of tetrapods 6,7, but palaeonto-logical data indicate that this epithelium as well as a middle ear, is already present in crossopterygian fish 8–10. However, no basilar papilla has been found in the only living crossopterygian species, the coelacanth Latimeria chalumnae 11. I have re-examined the inner ear of adult and embryonic Latimeria and find a membranous specialization which resembles in structure, position and innerva-tion pattern the basilar papilla of tetrapods, in particular amniotes. No epithelium comparable to the basilar papilla was found in lungfish. I suggest that the basilar papillae of Latimeria and tetrapods are homologous and evolved only once in their common ancestor.

  3. Streptomycin action to the mammalian inner ear vestibular organs: comparison between pigmented guinea pigs and rats.

    Meza, Graciela; Aguilar-Maldonado, Beatriz


    Streptomycin is the antibiotic of choice to treat tuberculosis and other infectious diseases but it causes vestibular malfunction and hipoacusia. Rodents are usually employed as models of drug action to the inner ear and results are extrapolated to what happens in humans. In rats, streptomycin destroys macular sensory cells and does not affect cochlear ones, whereas in guinea pigs the contrary is true. Action on the vestibular cristae cells involved in vestibulo-ocular reflex integrity is less clear. Thus, we compared this response in both pigmented guinea pigs (Cavia cobaya) and rats (Rattus norvegicus) after parallel streptomycin chronic treatment. In guinea pigs, the reflex was obliterated along treatment time; in rats this behavior was not observed, suggesting that the end organ target was diverse. In recent studies, streptidine, a streptomycin derivative found in the blood of humans and rats treated with streptomycin, was the actual ototoxic agent. The putative streptomycin vestibular organ target observed in humans corresponds with the guinea pig observations. Results observed in rats are controversial: streptidine did not cause any damage either to vestibular cristae nor auditory cells. We hypothesize differential drug metabolism and distribution and conclude that results in laboratory animals may not always be applicable in the human situation.

  4. Ear recognition based on Gabor features and KFDA.

    Yuan, Li; Mu, Zhichun


    We propose an ear recognition system based on 2D ear images which includes three stages: ear enrollment, feature extraction, and ear recognition. Ear enrollment includes ear detection and ear normalization. The ear detection approach based on improved Adaboost algorithm detects the ear part under complex background using two steps: offline cascaded classifier training and online ear detection. Then Active Shape Model is applied to segment the ear part and normalize all the ear images to the same size. For its eminent characteristics in spatial local feature extraction and orientation selection, Gabor filter based ear feature extraction is presented in this paper. Kernel Fisher Discriminant Analysis (KFDA) is then applied for dimension reduction of the high-dimensional Gabor features. Finally distance based classifier is applied for ear recognition. Experimental results of ear recognition on two datasets (USTB and UND datasets) and the performance of the ear authentication system show the feasibility and effectiveness of the proposed approach.

  5. Ear Recognition Based on Gabor Features and KFDA

    Li Yuan


    Full Text Available We propose an ear recognition system based on 2D ear images which includes three stages: ear enrollment, feature extraction, and ear recognition. Ear enrollment includes ear detection and ear normalization. The ear detection approach based on improved Adaboost algorithm detects the ear part under complex background using two steps: offline cascaded classifier training and online ear detection. Then Active Shape Model is applied to segment the ear part and normalize all the ear images to the same size. For its eminent characteristics in spatial local feature extraction and orientation selection, Gabor filter based ear feature extraction is presented in this paper. Kernel Fisher Discriminant Analysis (KFDA is then applied for dimension reduction of the high-dimensional Gabor features. Finally distance based classifier is applied for ear recognition. Experimental results of ear recognition on two datasets (USTB and UND datasets and the performance of the ear authentication system show the feasibility and effectiveness of the proposed approach.

  6. Change of guinea pig inner ear pressure by square wave middle ear cavity pressure variation

    Feijen, RA; Segenhout, JM; Albers, FWJ; Wit, HP

    The inner ear fluid pressure of guinea pigs was measured during square wave middle ear cavity pressure variation. Time constants were derived for the slopes of the inner ear pressure recovery curves after middle ear pressure change. A "single exponential" function did not fit well and therefore more

  7. Change of guinea pig inner ear pressure by square wave middle ear cavity pressure variation

    Feijen, RA; Segenhout, JM; Albers, FWJ; Wit, HP


    The inner ear fluid pressure of guinea pigs was measured during square wave middle ear cavity pressure variation. Time constants were derived for the slopes of the inner ear pressure recovery curves after middle ear pressure change. A "single exponential" function did not fit well and therefore more

  8. Can Loud Music Hurt My Ears?

    ... or Too Short All About Puberty Can Loud Music Hurt My Ears? KidsHealth > For Kids > Can Loud Music Hurt My Ears? Print A A A en ... up? Oh! You want to know if loud music can hurt your ears . Are you asking because ...

  9. 21 CFR 878.3590 - Ear prosthesis.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear prosthesis. 878.3590 Section 878.3590 Food and... GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3590 Ear prosthesis. (a) Identification. An ear prosthesis is a silicone rubber solid device intended to be implanted to reconstruct the...

  10. Can Loud Music Hurt My Ears?

    ... What Happens in the Operating Room? Can Loud Music Hurt My Ears? KidsHealth > For Kids > Can Loud Music Hurt My Ears? A A A en español ... up? Oh! You want to know if loud music can hurt your ears . Are you asking because ...

  11. Migration of R28 Retinal Precursor Cells into Cochlear and Vestibular Organs

    DING Dalian; Gail Seigel; Richard Salvi


    Damaged hair cells and neurons in the inner ear generally can not be replaced in mammals. The loss of these cells causes permanent functional disorders in both the cochlear and vestibular systems. Transplantation of retinal precursor cells, R28 cells, into inner ear tissue may help replace missing cells. The aim of the current project was to induce R28 cell transdifferentiation into cochlear and vestibular cell types under culture conditions. The first part was related to R28 cell labeling with DiI fluorescence that would help identify and track R28 cells. The second part involved co-culturing R28 cells in cochlear and vestibular organotropic cultures or isolated spiral ganglion neurons. The results suggest that R28 cells have the potential to differentiate into supporting cell types and spiral ganglion neurons in serum free medium, probably under the influence of diffusible signals from inner ear tissues. This information is useful for future efforts in inducing stem cell differentiation in the inner ear to replace lost sensory and neural cells.

  12. Myosin VIIa, harmonin and cadherin 23, three Usher I gene products that cooperate to shape the sensory hair cell bundle.

    Boëda, Batiste; El-Amraoui, Aziz; Bahloul, Amel; Goodyear, Richard; Daviet, Laurent; Blanchard, Stéphane; Perfettini, Isabelle; Fath, Karl R; Shorte, Spencer; Reiners, Jan; Houdusse, Anne; Legrain, Pierre; Wolfrum, Uwe; Richardson, Guy; Petit, Christine


    Deaf-blindness in three distinct genetic forms of Usher type I syndrome (USH1) is caused by defects in myosin VIIa, harmonin and cadherin 23. Despite being critical for hearing, the functions of these proteins in the inner ear remain elusive. Here we show that harmonin, a PDZ domain-containing protein, and cadherin 23 are both present in the growing stereocilia and that they bind to each other. Moreover, we demonstrate that harmonin b is an F-actin-bundling protein, which is thus likely to anchor cadherin 23 to the stereocilia microfilaments, thereby identifying a novel anchorage mode of the cadherins to the actin cytoskeleton. Moreover, harmonin b interacts directly with myosin VIIa, and is absent from the disorganized hair bundles of myosin VIIa mutant mice, suggesting that myosin VIIa conveys harmonin b along the actin core of the developing stereocilia. We propose that the shaping of the hair bundle relies on a functional unit composed of myosin VIIa, harmonin b and cadherin 23 that is essential to ensure the cohesion of the stereocilia.

  13. Clinical Application of 3D-FIESTA Image in Patients with Unilateral Inner Ear Symptom.

    Oh, Jae Ho; Chung, Jae Ho; Min, Hyun Jung; Cho, Seok Hyun; Park, Chul Won; Lee, Seung Hwan


    Unilateral auditory dysfunction such as tinnitus and hearing loss could be a warning sign of a retrocochlear lesion. Auditory brainstem response (ABR) and internal auditory canal magnetic resonance image (MRI) are suggested as novel diagnostic tools for retrocochlear lesions. However, the high cost of MRI and the low sensitivity of the ABR test could be an obstacle when assessing patients with unilateral ear symptoms. The purpose of this study was to introduce the clinical usefulness of three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) MRI in patients with unilateral ear symptoms. Two hundred and fifty-three patients with unilateral tinnitus or unilateral hearing loss who underwent 3D-FIESTA temporal bone MRI as a screening test were enrolled. We reviewed the abnormal findings in the 3D-FIESTA images and ear symptoms using the medical records. In patients with unilateral ear symptoms, 51.0% of the patients had tinnitus and 32.8% patients were assessed to have sudden sensory neural hearing loss. With 3D-FIESTA imaging, twelve patients were diagnosed with acoustic neuroma, four with enlarged vestibular aqueduct syndrome, and two with posterior inferior cerebellar artery aneurysm. Inner ear anomalies and vestibulocochlear nerve aplasia could be diagnosed with 3D-FIESTA imaging. 3D-FIESTA imaging is a highly sensitive method for the diagnosis of cochlear or retrocochlear lesions. 3D-FIESTA imaging is a useful screening tool for patients with unilateral ear symptoms.

  14. Sensory habituation of auditory receptor neurons: implications for sound localization.

    Givois, V; Pollack, G S


    Auditory receptor neurons exhibit sensory habituation; their responses decline with repeated stimulation. We studied the effects of sensory habituation on the neural encoding of sound localization cues using crickets as a model system. In crickets, Teleogryllus oceanicus, sound localization is based on binaural comparison of stimulus intensity. There are two potential codes at the receptor-neuron level for interaural intensity difference: interaural difference in response strength, i.e. spike rate and/or count, and interaural difference in response latency. These are affected differently by sensory habituation. When crickets are stimulated with cricket-song-like trains of sound pulses, response strength declines for successive pulses in the train, and the decrease becomes more pronounced as the stimulus intensity increases. Response decrement is thus greater for receptors serving the ear ipsilateral to the sound source, where intensity is higher, resulting in a decrease in the interaural difference in response strength. Sensory habituation also affects response latency, which increases for responses to successive sound pulses in the stimulus train. The change in latency is independent of intensity, and thus is similar for receptors serving both ears. As a result, interaural latency difference is unaffected by sensory habituation and may be a more reliable cue for sound localization.

  15. Inhibition of TRPA1 channel activity in sensory neurons by the glial cell line-derived neurotrophic factor family member, artemin

    Wang Shenglan


    Full Text Available Abstract Background The transient receptor potential (TRP channel subtype A1 (TRPA1 is known to be expressed on sensory neurons and respond to changes in temperature, pH and local application of certain noxious chemicals such as allyl isothiocyanate (AITC. Artemin is a neuronal survival and differentiation factor and belongs to the glial cell line-derived neurotrophic factor (GDNF family. Both TRPA1 and artemin have been reported to be involved in pathological pain initiation and maintenance. In the present study, using whole-cell patch clamp recording technique, in situ hybridization and behavioral analyses, we examined the functional interaction between TRPA1 and artemin. Results We found that 85.8 ± 1.9% of TRPA1-expressing neurons also expressed GDNF family receptor alpha 3 (GFR α3, and 87.5 ± 4.1% of GFRα3-expressing neurons were TRPA1-positive. In whole-cell patch clamp analysis, a short-term treatment of 100 ng/ml artemin significantly suppressed the AITC-induced TRPA1 currents. A concentration-response curve of AITC resulting from the effect of artemin showed that this inhibition did not change EC50 but did lower the AITC-induced maximum response. In addition, pre-treatment of artemin significantly suppressed the number of paw lifts induced by intraplantar injection of AITC, as well as the formalin-induced pain behaviors. Conclusions These findings that a short-term application of artemin inhibits the TRPA1 channel's activity and the sequential pain behaviors suggest a role of artemin in regulation of sensory neurons.

  16. LDV measurement of bird ear vibrations to determine inner ear impedance and middle ear power flow

    Muyshondt, Pieter G. G.; Pires, Felipe; Dirckx, Joris J. J.


    The mechanical behavior of the middle ear structures in birds and mammals is affected by the fluids in the inner ear (IE) that are present behind the oval window. In this study, the aim was to gather knowledge of the acoustic impedance of the IE in the ostrich, to be able to determine the effect on vibrations and power flow in the single-ossicle bird middle ear for future studies. To determine the IE impedance, vibrations of the ossicle were measured for both the quasi-static and acoustic stimulus frequencies. In the acoustic regime, vibrations were measured with a laser Doppler vibrometer and electromagnetic stimulation of the ossicle. The impedance of the inner ear could be determined by means of a simple RLC model in series, which resulted in a stiffness reactance of KIE = 0.20.1012 Pa/m3, an inertial impedance of MIE = 0.652.106 Pa s2/m3, and a resistance of RIE = 1.57.109 Pa s/m. The measured impedance is found to be considerably smaller than what is found for the human IE.

  17. Accessibility and sensory experiences

    Ryhl, Camilla


    This article introduces a new design concept; sensory accessibility. While acknowledging the importance of sensory experiences in architectural quality, as well as the importance of accommodating user needs the concept combines three equally important factors; architecture, the senses and accessi......This article introduces a new design concept; sensory accessibility. While acknowledging the importance of sensory experiences in architectural quality, as well as the importance of accommodating user needs the concept combines three equally important factors; architecture, the senses...... and accessibility. Sensory accessibility accommodates aspects of a sensory disability and describes architectural design requirements needed to ensure access to architectural experiences. In the context of architecture accessibility has become a design concept of its own. It is generally described as ensuring...... physical access to the built environment by accommodating physical disabilities. While the existing concept of accessibility ensures the physical access of everyone to a given space, sensory accessibility ensures the choice of everyone to stay and be able to participate and experience....

  18. Overexpression of partner of numb induces asymmetric distribution of the PI4P 5-Kinase Skittles in mitotic sensory organ precursor cells in Drosophila.

    Carolina N L R Perdigoto

    Full Text Available Unequal segregation of cell fate determinants at mitosis is a conserved mechanism whereby cell fate diversity can be generated during development. In Drosophila, each sensory organ precursor cell (SOP divides asymmetrically to produce an anterior pIIb and a posterior pIIa cell. The Par6-aPKC complex localizes at the posterior pole of dividing SOPs and directs the actin-dependent localization of the cell fate determinants Numb, Partner of Numb (Pon and Neuralized at the opposite pole. The plasma membrane lipid phosphatidylinositol (4,5-bisphosphate (PIP2 regulates the plasma membrane localization and activity of various proteins, including several actin regulators, thereby modulating actin-based processes. Here, we have examined the distribution of PIP2 and of the PIP2-producing kinase Skittles (Sktl in mitotic SOPs. Our analysis indicates that both Sktl and PIP2 reporters are uniformly distributed in mitotic SOPs. In the course of this study, we have observed that overexpression of full-length Pon or its localization domain (LD fused to the Red Fluorescent Protein (RFP::Pon(LD results in asymmetric distribution of Sktl and PIP2 reporters in dividing SOPs. Our observation that Pon overexpression alters polar protein distribution is relevant because RFP::Pon(LD is often used as a polarity marker in dividing progenitors.

  19. Study of orexins signal transduction pathways in rat olfactory mucosa and in olfactory sensory neurons-derived cell line Odora: multiple orexin signalling pathways.

    Gorojankina, Tatiana; Grébert, Denise; Salesse, Roland; Tanfin, Zahra; Caillol, Monique


    Orexins A and B (OxA and OxB) are multifunctional neuropeptides implicated in the regulation of energy metabolism, wakefulness but also in a broad range of motivated behaviours. They signal through two G-protein-coupled receptors: orexin receptor 1 and 2 (Ox1R and Ox2R). The orexins and their receptors are present at all levels of the rat olfactory system: epithelium, bulb, piriform cortex but their signalling mechanisms remain unknown. We have studied orexins signal transduction pathways in the rat olfactory mucosa (OM) and in the Odora cell line derived from olfactory sensory neurons and heterologously expressing Ox1R or Ox2R. We have demonstrated by western blot and RT-PCR that multiple components of adenylyl cyclase (AC) and phospholipase C (PLC) signalling pathways were identical in OM and Odora cells. OxA and OxB induced a weak increase in IP3 in OM; they induced a significant rise in cAMP and IP3 in Odora transfected cells, suggesting the activation of AC and PLC pathways. Both OxA and OxB induced intracellular calcium elevation and transient activation of MAP kinases (ERK42/44) in Odora/Ox1R and Odora/Ox2R cells. These results suggest the existence of multiple orexins signalling pathways in Odora cells and probably in OM, corresponding to different possible roles of these peptides.

  20. Carcinoid tumour of the middle ear

    Baig, Salman


    A case of middle ear mass in a young female from Ireland is described, who presented with left ear hearing loss and intermittent bloody discharge from the same ear. Examination under microscope revealed occlusive polyp in the left ear and a biopsy had been taken under general anaesthesia. Histopathology report described an adenoma \\/ carcinoid tumour of the middle ear confirmed by positive immunohistochemical staining. CT temporal bones revealed the extension of the disease. The patient underwent left tympanotomy and excision of the tumour. In general, these tumours are regarded as benign but may be mistaken for adenocarcinomas because of their histological heterogenecity.

  1. A Survey on Human Ear Recognition

    Suvarnsing Bhable


    Full Text Available This paper presents an efficient ear recognition technique which derives benefits from the local features of the ear and attempt to handle the problems due to pose, poor contrast, change in illumination and lack of registration. Recognizing humans by their ear have recently received significant attention in the field of research. Ear is the rich in characteristics. This paper provides a detailed survey of research done in ear detection and recognition. This survey paper is very useful in the current state-of- art for those who are working in this area and also for those who might exploit this new approach.

  2. A simple ear splint for microtia patients

    C J Venkata Krishnan


    Full Text Available Microtia is a congenital anomaly of the ear can occur as an isolated birth defect or as part of a spectrum of anomalies or as a syndrome. Microtia is often associated with impaired hearing and or total loss of hearing. Such patients typically require treatment for surgical ear reconstruction and for hearing impairment. Maintenance of ear projection and post auricular sulcus in staged ear reconstruction in microtia is a trying problem. So also is the maintenance of the patency of the external auditory meatus following recanalization and meatoplasty.This case report describes a simple effective way of fabrication of ear splint prosthesis.

  3. A simple ear splint for microtia patients.

    Krishnan, C J Venkata; Balaji, S M; Jain, Ashish R


    Microtia is a congenital anomaly of the ear can occur as an isolated birth defect or as part of a spectrum of anomalies or as a syndrome. Microtia is often associated with impaired hearing and or total loss of hearing. Such patients typically require treatment for surgical ear reconstruction and for hearing impairment. Maintenance of ear projection and post auricular sulcus in staged ear reconstruction in microtia is a trying problem. So also is the maintenance of the patency of the external auditory meatus following recanalization and meatoplasty.This case report describes a simple effective way of fabrication of ear splint prosthesis.

  4. Sensory receptors in monotremes.

    Proske, U; Gregory, J E; Iggo, A


    This is a summary of the current knowledge of sensory receptors in skin of the bill of the platypus, Ornithorhynchus anatinus, and the snout of the echidna, Tachyglossus aculeatus. Brief mention is also made of the third living member of the monotremes, the long-nosed echidna, Zaglossus bruijnii. The monotremes are the only group of mammals known to have evolved electroreception. The structures in the skin responsible for the electric sense have been identified as sensory mucous glands with an expanded epidermal portion that is innervated by large-diameter nerve fibres. Afferent recordings have shown that in both platypuses and echidnas the receptors excited by cathodal (negative) pulses and inhibited by anodal (positive) pulses. Estimates give a total of 40,000 mucous sensory glands in the upper and lower bill of the platypus, whereas there are only about 100 in the tip of the echidna snout. Recording of electroreceptor-evoked activity from the brain of the platypus have shown that the largest area dedicated to somatosensory input from the bill, S1, shows alternating rows of mechanosensory and bimodal neurons. The bimodal neurons respond to both electrosensory and mechanical inputs. In skin of the platypus bill and echidna snout, apart from the electroreceptors, there are structures called push rods, which consist of a column of compacted cells that is able to move relatively independently of adjacent regions of skin. At the base of the column are Merkel cell complexes, known to be type I slowly adapting mechanoreceptors, and lamellated corpuscles, probably vibration receptors. It has been speculated that the platypus uses its electric sense to detect the electromyographic activity from moving prey in the water and for obstacle avoidance. Mechanoreceptors signal contact with the prey. For the echidna, a role for the electrosensory system has not yet been established during normal foraging behaviour, although it has been shown that it is able to detect the presence

  5. Effect of Hypergravity on Carbonanhydrase Reactivity in inner Ear Ioncytes of developing Cichlid Fish

    Beier, M.; Anken, R.; Rahmann, H.

    It has been shown earlier that hypergravity slows down inner ear otolith growth in developing fish. Otolith growth in terms of mineralisation mainly depends on the enzyme carboanhydrase (CAH), which is responsible for the provision of the pH- value necessary for calcium carbonate deposition and thus also is presumed to play a prominent role in Ménière's disease (a sensory - motor disorder inducing vertigo and kinetosis). Larval siblings of cichlid fish (Oreochromis mossambicus) were subjected to hypergravity (3g; 6 hours) during development and separated into normally and kinetotically swimming individuals following the transfer to 1g (i.e., stopping the centrifuge; kinetotically behaving fish performed spinning movements). Subsequently, CAH was histochemically demonstrated in inner ear ionocytes (cells involved in the endolymphatic ion exchange) and enzyme reactivity was determined densitometrically. The results showed that CAH-reactivity was significantly increased in normally behaving hyper-g specimens as compared to controls kept at 1g, whereas no difference in enzyme reactivity was evident between the controls and kinetotically behaving fish. On the background of earlier studies, according to which (1) hypergravity induces a decrease of otolith growth and (2) the otolithic calcium incorporation (visualized using the calcium -tracer alizarin complexone) of kinetotically swimming hyper - g fish was lower as compared to normally behaving hyper - g animals, the present study strongly supports the concept that an increase in CAH-reactivity may result in a decrease of otolithic calcium deposition. The mechanism regulating CAH-activity hitherto remains to be determined. Acknowledgement: This work was financially supported by the German Aerospace Center (DLR) (FKZ: 50 WB 9997).

  6. Technique for correction of lop ear.

    Elsahy, N I


    Various techniques of correction of lop ear have been described. Minor lop ear deformity can easily be corrected with simple excision of the overhanging auricular cartilage. Moderate and severe lop ear deformities, on the other hand, are more difficult to correct because there is actual reduction in size of the upper third of the ear in addition to the overhanging auricular cartilage. The purpose of this paper was to present a new technique used to correct the moderate lop ear deformity. In addition to excising the overhanging cartilage, I rotate a cartilage flap from the anthelix upward where the missing superior crus was supposed to be. This flap increases the vertical height of the ear and creates a new superior crus. I applied this technique on three cases of moderate lop ear deformities with good results.

  7. Sonic hedgehog and retinoic Acid induce bone marrow-derived stem cells to differentiate into glutamatergic neural cells.

    Yu, Zhenhai; Wu, Shixing; Liu, Zhen; Lin, Haiyan; Chen, Lei; Yuan, Xinli; Zhang, Zhiying; Liu, Fang; Zhang, Chuansen


    Studies have showed that transplanted stem cells in the inner ear won't regenerate to replace the damaged sensory hair cells. They can spontaneously differentiate into mesenchymal cells and fibrocytes in the damaged inner ear. Only mature sensory cells of MSCs-derived possess the great potency for cell transplantation in the treatment of sensorineural hearing loss. So, we try to establish an efficient generation of the glutamatergic sensory neural phenotype for the cell transplantation of the hearing loss. We isolated MSCs from femoral and tibial bones according to their adherence to culture dishes. After purification, proliferation, and passaged, cells became homogeneous in appearance, showing more uniformity and grew in a monolayer with a typical spindle-shape morphology. The cell surface markers were assessed using FACS to characterize the isolated cells. For neural induction to harvest the glutamatergic sensory neurons, passage 3 MSCs were incubated with preinduced medium for 24 hr, and neural-induced medium for an additional 14 days. The cells exhibit a typical neural shape. RT-PCR analysis indicated that the mRNA levels of the neural cell marker nestin, Tau, MAP-2, β-tubulin III, GluR-3, and GluR-4 were higher compared with primary MSCs. Immunohistochemistry and western-blotting proofed that nestin, MAP-2, β-tubulin III, and GluR-4 proteins indeed exhibit their expression difference in the induced cells compared to the MSCs. We show an efficient protocol by the combined applications of Sonic Hedgehog (Shh) and Retinoic Acid (RA) to induce MSCs to differentiate into the glutamatergic sensory neuron which were identified from the morphological, biochemical, and molecular characteristics.

  8. Temporal precision and reliability in the velocity regime of a hair-cell sensory system: the mechanosensory lateral line of goldfish, Carassius auratus.

    Goulet, Julie; van Hemmen, J Leo; Jung, Sarah N; Chagnaud, Boris P; Scholze, Björn; Engelmann, Jacob


    Fish and aquatic frogs detect minute water motion by means of a specialized mechanosensory system, the lateral line. Ubiquitous in fish, the lateral-line system is characterized by hair-cell based sensory structures across the fish's surface called neuromasts. These neuromasts occur free-standing on the skin as superficial neuromasts (SN) or are recessed into canals as canal neuromasts. SNs respond to rapid changes of water velocity in a small layer of fluid around the fish, including the so-called boundary layer. Although omnipresent, the boundary layer's impact on the SN response is still a matter of debate. For the first time using an information-theoretic approach to this sensory system, we have investigated the SN afferents encoding capabilities. Combining covariance analysis, phase analysis, and modeling of recorded neuronal responses of primary lateral line afferents, we show that encoding by the SNs is adequately described as a linear, velocity-responsive mechanism. Afferent responses display a bimodal distribution of opposite Wiener kernels that likely reflected the two hair-cell populations within a given neuromast. Using frozen noise stimuli, we further demonstrate that SN afferents respond in an extremely precise manner and with high reproducibility across a broad frequency band (10-150 Hz), revealing that an optimal decoder would need to rely extensively on a temporal code. This was further substantiated by means of signal reconstruction of spike trains that were time shifted with respect to their original. On average, a time shift of 3.5 ms was enough to diminish the encoding capabilities of primary afferents by 70%. Our results further demonstrate that the SNs' encoding capability is linearly related to the stimulus outside the boundary layer, and that the boundary layer can, therefore, be neglected while interpreting lateral line response of SN afferents to hydrodynamic stimuli.

  9. Middle ear adenoma. A tumor displaying mucinous and neuroendocrine differentiation.

    Wassef, M; Kanavaros, P; Polivka, M; Nemeth, J; Monteil, J P; Frachet, B; Tran Ba Huy, P


    Middle ear adenoma (MEA) is a distinctive, rare entity that appears to be derived from the lining epithelium of the middle ear mucosa. We report four cases of MEA displaying the typical histologic growth pattern. Two distinct tumor cell immunophenotypes were identified in all cases; the first type exhibited positivity with anti-epithelial membrane antigen and anti-keratin antibodies, and the second type showed immunoreactivity with anti-keratin, anti-vimentin, and anti-neuron-specific enolase antibodies. Ultrastructural studies revealed bidirectional mucinous and neuroendocrine differentiation, demonstrated by the presence of two distinct cell types containing apically located mucous granules and basally concentrated neuroendocrine granules, respectively. The presence of neuroendocrine differentiation was supported by the immunohistochemical detection of vasoactive intestinal polypeptide in the tumor cells in one case and neuron-specific enolase in three cases. These findings suggest that the potential for mixed mucinous/neuroendocrine differentiation described in other endodermally derived tumors also exists in middle ear mucosa. We also believe that the rare lesions diagnosed as primary carcinoid tumors of the middle ear might in fact be MEA with predominant or only neuroendocrine differentiation. The clinical course of our four cases and our review of the pertinent literature confirm the benign nature of MEA and indicate that these tumors should be treated by complete local excision without additional therapy.

  10. Dominantly-inherited lop ears.

    Leung, Alexander K C; Kong, Albert Y F; Robson, W Lane M; McLeod, D Ross


    We describe a four-generation Chinese family that included five members who had an isolated bilateral lop ear anomaly. The presentation suggested a dominant mode of inheritance. The absence of male-to-male transmission does not exclude an X-linked dominant mode of inheritance. Since the phenotypic anomaly of the male proband was no more severe than the affected female members, an autosomal dominant mode of inheritance is most likely. 2007 Wiley-Liss, Inc

  11. Tachykinins, calcitonin gene-related peptide and neuropeptide Y in nerves of the mammalian thymus: interactions with mast cells in autonomic and sensory neuroimmunomodulation?

    Weihe, E; Müller, S; Fink, T; Zentel, H J


    By the use of light microscopic (LM) immunohistochemistry the distribution of tachykinin (TK)-, calcitonin gene-related peptide (CGRP)- and neuropeptide Y (NPY)-like immunoreactivity in nerves supplying the mammalian (rat, mouse, guinea-pig, cat) thymus gland has been determined. There were no interspecies variations. Fibres staining for TK and CGRP completely overlapped indicating coexistence. They were present in the capsule, in interlobular septa and in the corticomedullary boundary and occurred in perivascular and paravascular plexus supplying arteries, veins and the microvasculature. Some TK/CGRP-immunoreactive (ir) fibres travelled between lymphoid cells and close contacts with mast cells were frequent. NPY-ir fibres were different from those staining for TK/CGRP and predominated in the perivascular plexus of arterial blood vessels. Only very rarely they coursed in the lymphoid parenchyma. Intimate contacts of NPY-ir fibres with mast cells were less frequent than those of TK/CGRP-ir fibres. We conclude that the NPY innervation is mainly sympathetic noradrenergic while thymic nerves coding for TK and CGRP are most likely of sensory origin. These pathways may play a differential neuroimmunomodulatory role in the thymus, possibly via interaction with mast cells.

  12. Acute Putrescine Supplementation with Schwann Cell Implantation Improves Sensory and Serotonergic Axon Growth and Functional Recovery in Spinal Cord Injured Rats.

    Iorgulescu, J Bryan; Patel, Samik P; Louro, Jack; Andrade, Christian M; Sanchez, Andre R; Pearse, Damien D


    Schwann cell (SC) transplantation exhibits significant potential for spinal cord injury (SCI) repair and its use as a therapeutic modality has now progressed to clinical trials for subacute and chronic human SCI. Although SC implants provide a receptive environment for axonal regrowth and support functional recovery in a number of experimental SCI models, axonal regeneration is largely limited to local systems and the behavioral improvements are modest without additional combinatory approaches. In the current study we investigated whether the concurrent delivery of the polyamine putrescine, started either 30 min or 1 week after SCI, could enhance the efficacy of SCs when implanted subacutely (1 week after injury) into the contused rat spinal cord. Polyamines are ubiquitous organic cations that play an important role in the regulation of the cell cycle, cell division, cytoskeletal organization, and cell differentiation. We show that the combination of putrescine with SCs provides a significant increase in implant size, an enhancement in axonal (sensory and serotonergic) sparing and/or growth, and improved open field locomotion after SCI, as compared to SC implantation alone. These findings demonstrate that polyamine supplementation can augment the effectiveness of SCs when used as a therapeutic approach for subacute SCI repair.

  13. Inner-ear morphology of the New Zealand kiwi (Apteryx mantelli) suggests high-frequency specialization.

    Corfield, Jeremy R; Kubke, M Fabiana; Parsons, Stuart; Köppl, Christine


    The sensory systems of the New Zealand kiwi appear to be uniquely adapted to occupy a nocturnal ground-dwelling niche. In addition to well-developed tactile and olfactory systems, the auditory system shows specializations of the ear, which are maintained along the central nervous system. Here, we provide a detailed description of the auditory nerve, hair cells, and stereovillar bundle orientation of the hair cells in the North Island brown kiwi. The auditory nerve of the kiwi contained about 8,000 fibers. Using the number of hair cells and innervating nerve fibers to calculate a ratio of average innervation density showed that the afferent innervation ratio in kiwi was denser than in most other birds examined. The average diameters of cochlear afferent axons in kiwi showed the typical gradient across the tonotopic axis. The kiwi basilar papilla showed a clear differentiation of tall and short hair cells. The proportion of short hair cells was higher than in the emu and likely reflects a bias towards higher frequencies represented on the kiwi basilar papilla. The orientation of the stereovillar bundles in the kiwi basilar papilla showed a pattern similar to that in most other birds but was most similar to that of the emu. Overall, many features of the auditory nerve, hair cells, and stereovilli bundle orientation in the kiwi are typical of most birds examined. Some features of the kiwi auditory system do, however, support a high-frequency specialization, specifically the innervation density and generally small size of hair-cell somata, whereas others showed the presumed ancestral condition similar to that found in the emu.

  14. Strategies to regenerate hair cells: identification of progenitors and critical genes.

    Breuskin, Ingrid; Bodson, Morgan; Thelen, Nicolas; Thiry, Marc; Nguyen, Laurent; Belachew, Shibeshih; Lefebvre, Philippe P; Malgrange, Brigitte


    Deafness commonly results from a lesion of the sensory cells and/or of the neurons of the auditory part of the inner ear. There are currently no treatments designed to halt or reverse the progression of hearing loss. A key goal in developing therapy for sensorineural deafness is the identification of strategies to replace lost hair cells. In amphibians and birds, a spontaneous post-injury regeneration of all inner ear sensory hair cells occurs. In contrast, in the mammalian cochlea, hair cells are only produced during embryogenesis. Many studies have been carried out in order to demonstrate the persistence of endogenous progenitors. The present review is first focused on the occurrence of spontaneous supernumerary hair cells and on nestin positive precursors found in the organ of Corti. A second approach to regenerating hair cells would be to find genes essential for their differentiation. This review will also focus on critical genes for embryonic hair cell formation such as the cell cycle related proteins, the Atoh1 gene and the Notch signaling pathway. Understanding mechanisms that underlie hair cell production is an essential prerequisite to defining therapeutic strategies to regenerate hair cells in the mature inner ear.

  15. Regeneration of human-ear-shaped cartilage by co-culturing human microtia chondrocytes with BMSCs.

    Zhang, Lu; He, Aijuan; Yin, Zongqi; Yu, Zheyuan; Luo, Xusong; Liu, Wei; Zhang, Wenjie; Cao, Yilin; Liu, Yu; Zhou, Guangdong


    Previously, we had addressed the issues of shape control/maintenance of in vitro engineered human-ear-shaped cartilage. Thus, lack of applicable cell source had become a major concern that blocks clinical translation of this technology. Autologous microtia chondrocytes (MCs) and bone marrow stromal cells (BMSCs) were both promising chondrogenic cells that did not involve obvious donor site morbidity. However, limited cell availability of MCs and ectopic ossification of chondrogenically induced BMSCs in subcutaneous environment greatly restricted their applications in external ear reconstruction. The current study demonstrated that MCs possessed strong proliferation ability but accompanied with rapid loss of chondrogenic ability during passage, indicating a poor feasibility to engineer the entire ear using expanded MCs. Fortunately, the co-transplantation results of MCs and BMSCs (25% MCs and 75% BMSCs) demonstrated a strong chondroinductive ability of MCs to promote stable ectopic chondrogenesis of BMSCs in subcutaneous environment. Moreover, cell labeling demonstrated that BMSCs could transform into chondrocyte-like cells under the chondrogenic niche provided by co-cultured MCs. Most importantly, a human-ear-shaped cartilaginous tissue with delicate structure and proper elasticity was successfully constructed by seeding the mixed cells (MCs and BMSCs) into the pre-shaped biodegradable ear-scaffold followed by 12 weeks of subcutaneous implantation in nude mouse. These results may provide a promising strategy to construct stable ectopic cartilage with MCs and stem cells (BMSCs) for autologous external ear reconstruction.

  16. Morphological Studies of Digestive Tract and Its Argyrophil Cells in Sunken Ear Frog%凹耳蛙消化道组织学和嗜银细胞形态观察

    马雪泷; 唐鑫生; 吴仁红; 马亚军; 张蕾


    为了揭示凹耳蛙( Odorrana tormota)消化道的基本特征,运用石蜡切片法和龙桂开银浸法对凹耳蛙消化道组织学结构及嗜银细胞的形态与分布密度进行了观察.结果显示:①凹耳蛙的胃壁具明显的纵行皱襞和胃小凹,胃腺发达,小肠可分为十二指肠和回肠,杯状细胞分散在十二指肠上皮细胞之间,十二指肠中未见十二指肠腺分布.②凹耳蛙嗜银细胞见于消化道全长,呈毛笔头样、锥体形、梭形、椭圆形和长条形等;幽门腺上皮和十二指肠绒毛上皮中的嗜银细胞具指向腺泡腔或肠腔的突起,提示其可能具有腔分泌的功能.嗜银细胞的分布密度胃幽门部最高,十二指肠和胃体其次,食道最低.据此认为胃既是凹耳蛙的主要消化器官,也是消化道中主要的内分泌器官;十二指肠是凹耳蛙消化道中的主要吸收部位,同时也具有内分泌功能;消化道嗜银细胞具有内分泌的功能,还可能具有腔分泌的功能.%To reveal the basic characteristics of the digestive tract of Sunken Ear Frog( Odonana tormota) , paraffin section and Longguikai's silver staining were used to observe histological characteristics and distribution density of argyrophil cells in the digestive tract. Longitudinal plica and gastric pits were obviously observed on the gastric wall and glands were well developed. The small intestine could be divided into duodenum and ileum, with goblet cells scattered among the duodenum epithelial cells,while no glands were found in the duodenum. Argyrophil cells in various shapes, such as brush-headed, conical, spindle-like, elliptical and rectangular, were observed along the whole digestive tract, and these cells in gland epithelium of pilori and villus epithelium of duodenum had apophysis pointing to the acinar lumen or intestine, indicating the possible luminal secretion function of these cells. Pylorica part of suomach had the highest density of argyrophil cells

  17. Immune system of the inner ear as a novel therapeutic target for sensorineural hearing loss

    Takayuki eOkano


    Full Text Available Sensorineural hearing loss (SNHL is a common clinical condition resulting from dysfunction in one or more parts in the auditory pathway between the inner ear and auditory cortex. Despite the prevalence of SNHL, little is known about its etiopathology, although several mechanisms have been postulated including ischemia, viral infection or reactivation, and microtrauma. Immune-mediated inner ear disease has been introduced and accepted as one SNHL pathophysiology; it responds to immunosuppressive therapy and is one of the few reversible forms of bilateral SNHL. The concept of immune-mediated inner ear disease is straightforward and comprehensible, but criteria for clinical diagnosis and the precise mechanism of hearing loss have not been determined. Moreover, the therapeutic mechanisms of corticosteroids are unclear, leading to several misconceptions by both clinicians and investigators concerning corticosteroid therapy. This review addresses our current understanding of the immune system in the inner ear and its involvement in the pathophysiology in SNHL. Treatment of SNHL, including immune-mediated inner ear disorder, will be discussed with a focus on the immune mechanism and immunocompetent cells as therapeutic targets. Finally, possible interventions modulating the immune system in the inner ear to repair the tissue organization and improve hearing in patients with SNHL will be discussed. Tissue macrophages in the inner ear appear to be a potential target for modulating the immune response in the inner ear in the pathophysiology of SNHL.

  18. Manganese is Toxic to Spiral Ganglion Neurons and Hair Cells in Vitro

    Ding, Dalian; Roth, Jerome; Salvi, Richard


    Occupational exposure to high atmospheric levels of Mn produces a severe and debilitating disorder known as manganism characterized by extrapyramidal disturbances similar to that seen in Parkinson’s disease. Epidemiological and case studies suggest that persistent exposures to Mn may have deleterious effects on other organs including the auditory system and hearing. Mn accumulates in the inner ear following acute exposure raising the possibility that it can damage the sensory hair cells that ...

  19. Zona pellucida domain-containing protein β-tectorin is crucial for zebrafish proper inner ear development.

    Chung-Hsiang Yang

    Full Text Available BACKGROUND: The zona pellucida (ZP domain is part of many extracellular proteins with diverse functions from structural components to receptors. The mammalian β-tectorin is a protein of 336 amino acid residues containing a single ZP domain and a putative signal peptide at the N-terminus of the protein. It is 1 component of a gel-like structure called the tectorial membrane which is involved in transforming sound waves into neuronal signals and is important for normal auditory function. β-Tectorin is specifically expressed in the mammalian and avian inner ear. METHODOLOGY/PRINCIPAL FINDINGS: We identified and cloned the gene encoding zebrafish β-tectorin. Through whole-mount in situ hybridization, we demonstrated that β-tectorin messenger RNA was expressed in the otic placode and specialized sensory patch of the inner ear during zebrafish embryonic stages. Morpholino knockdown of zebrafish β-tectorin affected the position and number of otoliths in the ears of morphants. Finally, swimming behaviors of β-tectorin morphants were abnormal since the development of the inner ear was compromised. CONCLUSIONS/SIGNIFICANCE: Our results reveal that zebrafish β-tectorin is specifically expressed in the zebrafish inner ear, and is important for regulating the development of the zebrafish inner ear. Lack of zebrafish β-tectorin caused severe defects in inner ear formation of otoliths and function.

  20. Influence of Sensory Dependence on Postural Control

    Santana, Patricia A.; Mulavara, Ajitkumar P.; Fiedler, Matthew J.


    The current project is part of an NSBRI funded project, "Development of Countermeasures to Aid Functional Egress from the Crew Exploration Vehicle Following Long-Duration Spaceflight." The development of this countermeasure is based on the use of imperceptible levels of electrical stimulation to the balance organs of the inner ear to assist and enhance the response of a person s sensorimotor function. These countermeasures could be used to increase an astronaut s re-adaptation rate to Earth s gravity following long-duration space flight. The focus of my project is to evaluate and examine the correlation of sensory preferences for vision and vestibular systems. Disruption of the sensorimotor functions following space flight affects posture, locomotion and spatial orientation tasks in astronauts. The Group Embedded Figures Test (GEFT), the Rod and Frame Test (RFT) and the Computerized Dynamic Posturography Test (CDP) are measurements used to examine subjects visual and vestibular sensory preferences. The analysis of data from these tasks will assist in relating the visual dependence measures recognized in the GEFT and RFT with vestibular dependence measures recognized in the stability measures obtained during CDP. Studying the impact of sensory dependence on the performance in varied tasks will help in the development of targeted countermeasures to help astronauts readapt to gravitational changes after long duration space flight.

  1. Coenzyme Q10 protects hair cells against aminoglycoside.

    Kazuma Sugahara

    Full Text Available It is well known that the production of free radicals is associated with sensory cell death induced by an aminoglycoside. Many researchers have reported that antioxidant reagents protect sensory cells in the inner ear, and coenzyme Q10 (CoQ10 is an antioxidant that is consumed as a health food in many countries. The purpose of this study was to investigate the role of CoQ10 in mammalian vestibular hair cell death induced by aminoglycoside. Cultured utricles of CBA/CaN mice were divided into three groups (control group, neomycin group, and neomycin + CoQ10 group. In the neomycin group, utricles were cultured with neomycin (1 mM to induce hair cell death. In the neomycin + CoQ10 group, utricles were cultured with neomycin and water-soluble CoQ10 (30-0.3 µM. Twenty-four hours after exposure to neomycin, the cultured tissues were fixed, and vestibular hair cells were labeled using an anti-calmodulin antibody. Significantly more hair cells survived in the neomycin + CoQ10 group than in the neomycin group. These data indicate that CoQ10 protects sensory hair cells against neomycin-induced death in the mammalian vestibular epithelium; therefore, CoQ10 may be useful as a protective drug in the inner ear.

  2. Communication shapes sensory response in multicellular networks.

    Potter, Garrett D; Byrd, Tommy A; Mugler, Andrew; Sun, Bo


    Collective sensing by interacting cells is observed in a variety of biological systems, and yet, a quantitative understanding of how sensory information is collectively encoded is lacking. Here, we investigate the ATP-induced calcium dynamics of monolayers of fibroblast cells that communicate via gap junctions. Combining experiments and stochastic modeling, we find that increasing the ATP stimulus increases the propensity for calcium oscillations, despite large cell-to-cell variability. The model further predicts that the oscillation propensity increases with not only the stimulus, but also the cell density due to increased communication. Experiments confirm this prediction, showing that cell density modulates the collective sensory response. We further implicate cell-cell communication by coculturing the fibroblasts with cancer cells, which we show act as "defects" in the communication network, thereby reducing the oscillation propensity. These results suggest that multicellular networks sit at a point in parameter space where cell-cell communication has a significant effect on the sensory response, allowing cells to simultaneously respond to a sensory input and the presence of neighbors.

  3. Optical assessment of middle ear inflammation

    Jung, David S.


    This thesis describes the development of an optical device to assess the inflammatory state of the middle ear mucosa through the ear canal, after ventilation tube insertion in otitis media with effusion in children. An optical phantom of the middle ear was developed in order to allow repeatable experiments. The phantom consists of eardrum and mucosa while all other structures are neglected. The optical properties of the phantom were determined based on literature review and experiments on...

  4. HIV Associated Sensory Neuropathy

    G, Amruth; S, Praveen-kumar; B, Nataraju; BS, Nagaraja


    Background: In the era of highly active antiretroviral therapy, sensory neuropathies have increased in prevalence. We have documented the frequency and profile of the two most common forms of sensory neuropathies associated with Human Immunodeficiency Virus (HIV) infection and looked into clinicoelectrophysiological correlates to differentiate the two entities.


    Vladimír Vietoris


    Full Text Available Sensory science is the young but the rapidly developing field of the food industry. Actually, the great emphasis is given to the production of rapid techniques of data collection, the difference between consumers and trained panel is obscured and the role of sensory methodologists is to prepare the ways for evaluation, by which a lay panel (consumers can achieve identical results as a trained panel. Currently, there are several conventional methods of sensory evaluation of food (ISO standards, but more sensory laboratories are developing methodologies that are not strict enough in the selection of evaluators, their mechanism is easily understandable and the results are easily interpretable. This paper deals with mapping of marginal methods used in sensory evaluation of food (new types of profiles, CATA, TDS, napping.

  6. An Effective 3D Ear Acquisition System.

    Yahui Liu

    Full Text Available The human ear is a new feature in biometrics that has several merits over the more common face, fingerprint and iris biometrics. It can be easily captured from a distance without a fully cooperative subject. Also, the ear has a relatively stable structure that does not change much with the age and facial expressions. In this paper, we present a novel method of 3D ear acquisition system by using triangulation imaging principle, and the experiment results show that this design is efficient and can be used for ear recognition.

  7. An Effective 3D Ear Acquisition System.

    Liu, Yahui; Lu, Guangming; Zhang, David


    The human ear is a new feature in biometrics that has several merits over the more common face, fingerprint and iris biometrics. It can be easily captured from a distance without a fully cooperative subject. Also, the ear has a relatively stable structure that does not change much with the age and facial expressions. In this paper, we present a novel method of 3D ear acquisition system by using triangulation imaging principle, and the experiment results show that this design is efficient and can be used for ear recognition.

  8. Pyridoxine dependent epilepsy with iatrogenic sensory neuronopathy.

    McLachlan, R S; Brown, W F


    An 18-year-old man was treated from birth with chronic high dose pyridoxine (vitamin B6) up to 2000 mg per day for pyridoxine-dependent seizures. Within two years of onset of treatment, he developed a sensory neuropathy which did not progress over the following 16 years. Electrophysiological studies were consistent with a pure sensory neuronopathy expressed as centripetal degeneration of processes of the dorsal root ganglion cells.

  9. The microRNA bantam regulates a developmental transition in epithelial cells that restricts sensory dendrite growth.

    Jiang, Nan; Soba, Peter; Parker, Edward; Kim, Charles C; Parrish, Jay Z


    As animals grow, many early born structures grow by cell expansion rather than cell addition; thus growth of distinct structures must be coordinated to maintain proportionality. This phenomenon is particularly widespread in the nervous system, with dendrite arbors of many neurons expanding in concert with their substrate to sustain connectivity and maintain receptive field coverage as animals grow. After rapidly growing to establish body wall coverage, dendrites of Drosophila class IV dendrite arborization (C4da) neurons grow synchronously with their substrate, the body wall epithelium, providing a system to study how proportionality is maintained during animal growth. Here, we show that the microRNA bantam (ban) ensures coordinated growth of C4da dendrites and the epithelium through regulation of epithelial endoreplication, a modified cell cycle that entails genome amplification without cell division. In Drosophila larvae, epithelial endoreplication leads to progressive changes in dendrite-extracellular matrix (ECM) and dendrite-epithelium contacts, coupling dendrite/substrate expansion and restricting dendrite growth beyond established boundaries. Moreover, changes in epithelial expression of cell adhesion molecules, including the beta-integrin myospheroid (mys), accompany this developmental transition. Finally, endoreplication and the accompanying changes in epithelial mys expression are required to constrain late-stage dendrite growth and structural plasticity. Hence, modulating epithelium-ECM attachment probably influences substrate permissivity for dendrite growth and contributes to the dendrite-substrate coupling that ensures proportional expansion of the two cell types.

  10. A Calcium- and Diacylglycerol-Stimulated Protein Kinase C (PKC), Caenorhabditis elegans PKC-2, Links Thermal Signals to Learned Behavior by Acting in Sensory Neurons and Intestinal Cells.

    Land, Marianne; Rubin, Charles S


    Ca(2+)- and diacylglycerol (DAG)-activated protein kinase C (cPKC) promotes learning and behavioral plasticity. However, knowledge of in vivo regulation and exact functions of cPKCs that affect behavior is limited. We show that PKC-2, a Caenorhabditis elegans cPKC, is essential for a complex behavior, thermotaxis. C. elegans memorizes a nutrient-associated cultivation temperature (Tc ) and migrates along the Tc within a 17 to 25°C gradient. pkc-2 gene disruption abrogated thermotaxis; a PKC-2 transgene, driven by endogenous pkc-2 promoters, restored thermotaxis behavior in pkc-2(-/-) animals. Cell-specific manipulation of PKC-2 activity revealed that thermotaxis is controlled by cooperative PKC-2-mediated signaling in both AFD sensory neurons and intestinal cells. Cold-directed migration (cryophilic drive) precedes Tc tracking during thermotaxis. Analysis of temperature-directed behaviors elicited by persistent PKC-2 activation or inhibition in AFD (or intestine) disclosed that PKC-2 regulates initiation and duration of cryophilic drive. In AFD neurons, PKC-2 is a Ca(2+) sensor and signal amplifier that operates downstream from cyclic GMP-gated cation channels and distal guanylate cyclases. UNC-18, which regulates neurotransmitter and neuropeptide release from synaptic vesicles, is a critical PKC-2 effector in AFD. UNC-18 variants, created by mutating Ser(311) or Ser(322), disrupt thermotaxis and suppress PKC-2-dependent cryophilic migration. Copyright © 2017 American Society for Microbiology.

  11. Processing of simple and complex acoustic signals in a tonotopically organized ear.

    Hummel, Jennifer; Wolf, Konstantin; Kössl, Manfred; Nowotny, Manuela


    Processing of complex signals in the hearing organ remains poorly understood. This paper aims to contribute to this topic by presenting investigations on the mechanical and neuronal response of the hearing organ of the tropical bushcricket species Mecopoda elongata to simple pure tone signals as well as to the conspecific song as a complex acoustic signal. The high-frequency hearing organ of bushcrickets, the crista acustica (CA), is tonotopically tuned to frequencies between about 4 and 70 kHz. Laser Doppler vibrometer measurements revealed a strong and dominant low-frequency-induced motion of the CA when stimulated with either pure tone or complex stimuli. Consequently, the high-frequency distal area of the CA is more strongly deflected by low-frequency-induced waves than by high-frequency-induced waves. This low-frequency dominance will have strong effects on the processing of complex signals. Therefore, we additionally studied the neuronal response of the CA to native and frequency-manipulated chirps. Again, we found a dominant influence of low-frequency components within the conspecific song, indicating that the mechanical vibration pattern highly determines the neuronal response of the sensory cells. Thus, we conclude that the encoding of communication signals is modulated by ear mechanics.

  12. The middle ear immune defense changes with age.

    Nielsen, Michelle Christine; Friis, Morten; Martin-Bertelsen, Tomas; Winther, Ole; Friis-Hansen, Lennart; Cayé-Thomasen, Per


    Otitis media is a common disease in childhood. In adults, the disease is relatively rare, but more frequently associated with complications. Possible reasons for this discrepancy are age-related differences in pathogen exposure, anatomy of the Eustachian tube and immune system. The objective of this study was to analyze the relationship between age and the mucosal immune system in the middle ear. It is hypothesized that genes involved in the middle ear immune system will change with age. A comprehensive assessment of these genetic differences using the techniques of complementary DNA has not been performed. Complementary DNA microarray technology was used to identify immune-related genes differentially expressed between the normal middle ear mucosa of young (10 days old) and adult rats (80 days old). Data were analyzed using tools of bioinformatics. A total of 260 age-related genes were identified, of which 51 genes were involved in the middle ear mucosal immune system. Genes related to the innate immune system, including alpha-defensin, calcium-binding proteins S100A9 and S100A8, were upregulated in young rats, whereas genes related to the adaptive immune system, including CD3 molecules, zeta-chain T-cell receptor-associated protein kinase and linker of activated T-cells, were upregulated in the adult. This study concludes that the normal middle ear immune system changes with age. Genes related to the innate immune system are upregulated in young rats, whereas genes related to the adaptive immune system are upregulated in adults.

  13. The formation of endoderm-derived taste sensory organs requires a Pax9-dependent expansion of embryonic taste bud progenitor cells.

    Ralf Kist


    Full Text Available In mammals, taste buds develop in different regions of the oral cavity. Small epithelial protrusions form fungiform papillae on the ectoderm-derived dorsum of the tongue and contain one or few taste buds, while taste buds in the soft palate develop without distinct papilla structures. In contrast, the endoderm-derived circumvallate and foliate papillae located at the back of the tongue contain a large number of taste buds. These taste buds cluster in deep epithelial trenches, which are generated by intercalating a period of epithelial growth between initial placode formation and conversion of epithelial cells into sensory cells. How epithelial trench formation is genetically regulated during development is largely unknown. Here we show that Pax9 acts upstream of Pax1 and Sox9 in the expanding taste progenitor field of the mouse circumvallate papilla. While a reduced number of taste buds develop in a growth-retarded circumvallate papilla of Pax1 mutant mice, its development arrests completely in Pax9-deficient mice. In addition, the Pax9 mutant circumvallate papilla trenches lack expression of K8 and Prox1 in the taste bud progenitor cells, and gradually differentiate into an epidermal-like epithelium. We also demonstrate that taste placodes of the soft palate develop through a Pax9-dependent induction. Unexpectedly, Pax9 is dispensable for patterning, morphogenesis and maintenance of taste buds that develop in ectoderm-derived fungiform papillae. Collectively, our data reveal an endoderm-specific developmental program for the formation of taste buds and their associated papilla structures. In this pathway, Pax9 is essential to generate a pool of taste bud progenitors and to maintain their competence towards prosensory cell fate induction.

  14. The formation of endoderm-derived taste sensory organs requires a Pax9-dependent expansion of embryonic taste bud progenitor cells.

    Kist, Ralf; Watson, Michelle; Crosier, Moira; Robinson, Max; Fuchs, Jennifer; Reichelt, Julia; Peters, Heiko


    In mammals, taste buds develop in different regions of the oral cavity. Small epithelial protrusions form fungiform papillae on the ectoderm-derived dorsum of the tongue and contain one or few taste buds, while taste buds in the soft palate develop without distinct papilla structures. In contrast, the endoderm-derived circumvallate and foliate papillae located at the back of the tongue contain a large number of taste buds. These taste buds cluster in deep epithelial trenches, which are generated by intercalating a period of epithelial growth between initial placode formation and conversion of epithelial cells into sensory cells. How epithelial trench formation is genetically regulated during development is largely unknown. Here we show that Pax9 acts upstream of Pax1 and Sox9 in the expanding taste progenitor field of the mouse circumvallate papilla. While a reduced number of taste buds develop in a growth-retarded circumvallate papilla of Pax1 mutant mice, its development arrests completely in Pax9-deficient mice. In addition, the Pax9 mutant circumvallate papilla trenches lack expression of K8 and Prox1 in the taste bud progenitor cells, and gradually differentiate into an epidermal-like epithelium. We also demonstrate that taste placodes of the soft palate develop through a Pax9-dependent induction. Unexpectedly, Pax9 is dispensable for patterning, morphogenesis and maintenance of taste buds that develop in ectoderm-derived fungiform papillae. Collectively, our data reveal an endoderm-specific developmental program for the formation of taste buds and their associated papilla structures. In this pathway, Pax9 is essential to generate a pool of taste bud progenitors and to maintain their competence towards prosensory cell fate induction.

  15. MicroRNAs in sensorineural diseases of the ear

    Kathy eUshakov


    Full Text Available Non-coding microRNAs have a fundamental role in gene regulation and expression in almost every multicellular organism. Only discovered in the last decade, microRNAs are already known to play a leading role in many aspects of disease. In the vertebrate inner ear, microRNAs are essential for controlling development and survival of hair cells. Moreover, dysregulation of microRNAs has been implicated in sensorineural hearing impairment, as well as in other ear diseases such as cholesteatomas, vestibular schwannomas and otitis media. Due to the inaccessibility of the ear in humans, animal models have provided the optimal tools to study microRNA expression and function, in particular mice and zebrafish. A major focus of current research has been to discover the targets of the microRNAs expressed in the inner ear, in order to determine the regulatory pathways of the auditory and vestibular systems. The potential for microRNA manipulation in development of therapeutic tools for hearing impairment is as yet unexplored, paving the way for future work in the field.

  16. Cajal body number and nucleolar size correlate with the cell body mass in human sensory ganglia neurons.

    Berciano, Maria T; Novell, Mariona; Villagra, Nuria T; Casafont, Iñigo; Bengoechea, Rocio; Val-Bernal, J Fernado; Lafarga, Miguel


    This paper studies the cell size-dependent organization of the nucleolus and Cajal bodies (CBs) in dissociated human dorsal root ganglia (DRG) neurons from autopsy tissue samples of patients without neurological disease. The quantitative analysis of nucleoli with an anti-fibrillarin antibody showed that all neurons have only one nucleolus. However, the nucleolar volume and the number of fibrillar centers per nucleolus significantly increase as a function of cell body size. Immunostaining for coilin demonstrated the presence of numerous CBs in DRG neurons (up to 20 in large size neurons). The number of CBs per neuron correlated positively with the cell body volume. Light and electron microscopy immunocytochemical analysis revealed the concentration of coilin, snRNPs, SMN and fibrillarin in CBs of DRG neurons. CBs were frequently associated with the nucleolus, active chromatin domains and PML bodies, but not with telomeres. Our results support the view that the nucleolar volume and number of both fibrillar centers and CBs depend on the cell body mass, a parameter closely related to transcriptional and synaptic activity in mammalian neurons. Moreover, the unusual large number of CBs could facilitate the transfer of RNA processing components from CBs to nucleolar and nucleoplasmic sites of RNA processing.

  17. Effects of NSAIDs on the Inner Ear: Possible Involvement in Cochlear Protection

    Akira Hara


    Full Text Available Cyclooxygenase and lipoxygenase, two important enzymes involved in arachidonic acid metabolism, are major targets of non-steroidal anti-inflammatory drugs (NSAIDs. Recent investigations suggest that arachidonic cascades and their metabolites may be involved in maintaining inner ear functions. The excessive use of aspirin may cause tinnitus in humans and impairment of the outer hair cell functions in experimental animals. On the other hand, NSAIDs reportedly exhibit protective effects against various kinds of inner ear disorder. The present review summarizes the effects of NSAIDs on cochlear pathophysiology. NSAIDs are a useful ameliorative adjunct in the management of inner ear disorders.

  18. Mesenchymal stem cells in a polycaprolactone conduit promote sciatic nerve regeneration and sensory neuron survival after nerve injury.

    Frattini, Flávia; Lopes, Fatima Rosalina Pereira; Almeida, Fernanda Martins; Rodrigues, Rafaela Fintelman; Boldrini, Leonardo Cunha; Tomaz, Marcelo A; Baptista, Abrahão Fontes; Melo, Paulo A; Martinez, Ana Maria Blanco


    Despite the fact that the peripheral nervous system is able to regenerate after traumatic injury, the functional outcomes following damage are limited and poor. Bone marrow mesenchymal stem cells (MSCs) are multipotent cells that have been used in studies of peripheral nerve regeneration and have yielded promising results. The aim of this study was to evaluate sciatic nerve regeneration and neuronal survival in mice after nerve transection followed by MSC treatment into a polycaprolactone (PCL) nerve guide. The left sciatic nerve of C57BL/6 mice was transected and the nerve stumps were placed into a biodegradable PCL tube leaving a 3-mm gap between them; the tube was filled with MSCs obtained from GFP+ animals (MSC-treated group) or with a culture medium (Dulbecco's modified Eagle's medium group). Motor function was analyzed according to the sciatic functional index (SFI). After 6 weeks, animals were euthanized, and the regenerated sciatic nerve, the dorsal root ganglion (DRG), the spinal cord, and the gastrocnemius muscle were collected and processed for light and electron microscopy. A quantitative analysis of regenerated nerves showed a significant increase in the number of myelinated fibers in the group that received, within the nerve guide, stem cells. The number of neurons in the DRG was significantly higher in the MSC-treated group, while there was no difference in the number of motor neurons in the spinal cord. We also found higher values of trophic factors expression in MSC-treated groups, especially a nerve growth factor. The SFI revealed a significant improvement in the MSC-treated group. The gastrocnemius muscle showed an increase in weight and in the levels of creatine phosphokinase enzyme, suggesting an improvement of reinnervation and activity in animals that received MSCs. Immunohistochemistry documented that some GFP+ -transplanted cells assumed a Schwann-cell-like phenotype, as evidenced by their expression of the S-100 protein, a Schwann cell

  19. Sensory Coding in Oscillatory Peripheral Receptors

    Neiman, Alexander


    Rhythmical activity have been observed in several types of peripheral sensory receptors, e.g. in senses of hearing, balance and electroreception. We use two examples of spontaneously oscillating peripheral sensory receptors: bullfrog saccular hair cells and electroreceptors of paddlefish, to discuss how oscillations emerge, how these sensors may utilize oscillations to optimize their sensitivity and information processing. In the hair cell system oscillations occur on two very different levels: first, the mechano-sensory hair bundle itself can undergo spontaneous mechanical oscillations and second, self-sustained voltage oscillations across the membrane of the hair cell have been documented. Modelling show that interaction of these two compartment results in enhanced sensitivity to periodic mechanical stimuli. The second example, a single peripheral electroreceptor, is a complex system comprised of several thousands of sensory epithelial cells innervated by a few primary sensory neurons. It embeds two distinct oscillators: one residing in a population of epithelial cells, synaptically coupled to another oscillator residing in a branched myelinated afferent axon. We show how neuronal oscillations emerge in a complex network of excitable nodes. We further demonstrate that epithelial oscillations results in extended serial correlations of neruonal discharges enhancing coding of external stimuli.

  20. Evidence for involvement of Wnt signalling in body polarities, cell proliferation, and the neuro-sensory system in an adult ctenophore.

    Muriel Jager

    Full Text Available Signalling through the Wnt family of secreted proteins originated in a common metazoan ancestor and greatly influenced the evolution of animal body plans. In bilaterians, Wnt signalling plays multiple fundamental roles during embryonic development and in adult tissues, notably in axial patterning, neural development and stem cell regulation. Studies in various cnidarian species have particularly highlighted the evolutionarily conserved role of the Wnt/β-catenin pathway in specification and patterning of the primary embryonic axis. However in another key non-bilaterian phylum, Ctenophora, Wnts are not involved in early establishment of the body axis during embryogenesis. We analysed the expression in the adult of the ctenophore Pleurobrachia pileus of 11 orthologues of Wnt signalling genes including all ctenophore Wnt ligands and Fz receptors and several members of the intracellular β-catenin pathway machinery. All genes are strongly expressed around the mouth margin at the oral pole, evoking the Wnt oral centre of cnidarians. This observation is consistent with primary axis polarisation by the Wnts being a universal metazoan feature, secondarily lost in ctenophores during early development but retained in the adult. In addition, local expression of Wnt signalling genes was seen in various anatomical structures of the body including in the locomotory comb rows, where their complex deployment suggests control by the Wnts of local comb polarity. Other important contexts of Wnt involvement which probably evolved before the ctenophore/cnidarian/bilaterian split include proliferating stem cells and progenitors irrespective of cell types, and developing as well as differentiated neuro-sensory structures.

  1. Effect of ionizing radiation in sensory ganglion neurons: organization and dynamics of nuclear compartments of DNA damage/repair and their relationship with transcription and cell cycle.

    Casafont, Iñigo; Palanca, Ana; Lafarga, Vanesa; Berciano, Maria T; Lafarga, Miguel


    Neurons are very sensitive to DNA damage induced by endogenous and exogenous genotoxic agents, as defective DNA repair can lead to neurodevelopmental disorders, brain tumors and neurodegenerative diseases with severe clinical manifestations. Understanding the impact of DNA damage/repair mechanisms on the nuclear organization, particularly on the regulation of transcription and cell cycle, is essential to know the pathophysiology of defective DNA repair syndromes. In this work, we study the nuclear architecture and spatiotemporal organization of chromatin compartments involved in the DNA damage response (DDR) in rat sensory ganglion neurons exposed to X-ray irradiation (IR). We demonstrate that the neuronal DDR involves the formation of two categories of DNA-damage processing chromatin compartments: transient, disappearing within the 1 day post-IR, and persistent, where unrepaired DNA is accumulated. Both compartments concentrate components of the DDR pathway, including γH2AX, pATM and 53BP1. Furthermore, DNA damage does not induce neuronal apoptosis but triggers the G0-G1 cell cycle phase transition, which is mediated by the activation of the ATM-p53 pathway and increased protein levels of p21 and cyclin D1. Moreover, the run on transcription assay reveals a severe inhibition of transcription at 0.5 h post-IR, followed by its rapid recovery over the 1 day post-IR in parallel with the progression of DNA repair. Therefore, the response of healthy neurons to DNA damage involves a transcription- and cell cycle-dependent but apoptosis-independent process. Furthermore, we propose that the segregation of unrepaired DNA in a few persistent chromatin compartments preserves genomic stability of undamaged DNA and the global transcription rate in neurons.

  2. Inflammatory responses to Hydroxyapatite implants in middle ear in rats

    YE Qing; JIANG Yi; WANG Xiao-yan; ZHENG Ke-fei


    Objective To study local inflammatory response after implantation of hydroxyapatite synthetic ossicular prosthesis. Methods Hydroxyapatite gantries were implanted in the bulla in 32 rats. Sham surgical procedures were performed in 10 rats as the control. Animals were sacrificed at 1 to 300 days after surgery. Bulla sections, stained with HE and Mallory's azan, were examined for numbers and percentages of various inflammatory cell types. Results Slightly more inflammatory reaction was seen in animals with the implant than in the controls, mostly during the early stage following the implantation procedure. Few inflammatory cells were observed at later times. There were satisfactory fibrosis in both implanted and control ears. Conclusion The results indicate that hydroxyapatite synthetic prosthesis is a biocompatible implantation material in the middle ear. Nonetheless, the presence of inflammatory reaction immediately following implantation implies that control of infection is important in the early times after the implantation procedure.

  3. The middle ear immune defense changes with age

    Nielsen, Michelle Christine; Friis, Morten; Martin-Bertelsen, Tomas


    , of which 51 genes were involved in the middle ear mucosal immune system. Genes related to the innate immune system, including alpha-defensin, calcium-binding proteins S100A9 and S100A8, were upregulated in young rats, whereas genes related to the adaptive immune system, including CD3 molecules, zeta......-chain T-cell receptor-associated protein kinase and linker of activated T-cells, were upregulated in the adult. This study concludes that the normal middle ear immune system changes with age. Genes related to the innate immune system are upregulated in young rats, whereas genes related to the adaptive......Otitis media is a common disease in childhood. In adults, the disease is relatively rare, but more frequently associated with complications. Possible reasons for this discrepancy are age-related differences in pathogen exposure, anatomy of the Eustachian tube and immune system. The objective...

  4. Playing by Ear: Foundation or Frill?

    Woody, Robert H.


    Many people divide musicians into two types: those who can read music and those who play by ear. Formal music education tends to place great emphasis on producing musically literate performers but devotes much less attention to teaching students to make music without notation. Some would suggest that playing by ear is a specialized skill that is…

  5. Objective Audiometry using Ear-EEG

    Christensen, Christian Bech; Kidmose, Preben

    life. Ear-EEG may therefore be an enabling technology for objective audiometry out of the clinic, allowing regularly fitting of the hearing aids to be made by the users in their everyday life environment. In this study we investigate the application of ear-EEG in objective audiometry....


    The anatomy and developmental molecular genetics of the inner ear from establishment of the otic placode to formation of the definitive cochlea and vestibular apparatus will be reviewed and the complex 3-D structural changes that shape the developing inner ear will be illustrated...

  7. Coupled ears in lizards and crocodilians

    Carr, Catherine E; Christensen-Dalsgaard, Jakob; Bierman, Hilary


    Lizard ears are coupled across the pharynx, and are very directional. In consequence all auditory responses should be directional, without a requirement for computation of sound source location. Crocodilian ears are connected through sinuses, and thus less tightly coupled. Coupling may improve...

  8. 3D printing of composite tissue with complex shape applied to ear regeneration.

    Lee, Jung-Seob; Hong, Jung Min; Jung, Jin Woo; Shim, Jin-Hyung; Oh, Jeong-Hoon; Cho, Dong-Woo


    In the ear reconstruction field, tissue engineering enabling the regeneration of the ear's own tissue has been considered to be a promising technology. However, the ear is known to be difficult to regenerate using traditional methods due to its complex shape and composition. In this study, we used three-dimensional (3D) printing technology including a sacrificial layer process to regenerate both the auricular cartilage and fat tissue. The main part was printed with poly-caprolactone (PCL) and cell-laden hydrogel. At the same time, poly-ethylene-glycol (PEG) was also deposited as a sacrificial layer to support the main structure. After complete fabrication, PEG can be easily removed in aqueous solutions, and the procedure for removing PEG has no effect on the cell viability. For fabricating composite tissue, chondrocytes and adipocytes differentiated from adipose-derived stromal cells were encapsulated in hydrogel to dispense into the cartilage and fat regions, respectively, of ear-shaped structures. Finally, we fabricated the composite structure for feasibility testing, satisfying expectations for both the geometry and anatomy of the native ear. We also carried out in vitro assays for evaluating the chondrogenesis and adipogenesis of the cell-printed structure. As a result, the possibility of ear regeneration using 3D printing technology which allowed tissue formation from the separately printed chondrocytes and adipocytes was demonstrated.

  9. Microbiology of discharging ears in Ethiopia

    Getachew Tesfaye; Daniel Asrat; Yimtubezinash Woldeamanuel; Messele Gizaw


    Objectives:To isolate and identify the bacterial etiologic agents,including their antibiotic susceptibility pat-tern isolated from patients with discharging ear infections.Methods:Between September 2006 and February 2007,178 patients with discharging ear visiting ENT clinics of St.Paul and Tikur Anbessa University Hospi-tals Addis Ababa,Ethiopia were investigated.Results:Of the patients investigated,52.8% were males and 47.2% were females resulting in an overall male to female ratio of 1.1:1.Ear discharge was the commonest clinical finding followed by hearing problem (91.2%),otalgia (ear pain)(74.7%),fever (17.9%)and itching of external ear (5.1%).S.aureus accounted for 30.2% of the total isolates followed by Proteus ssp. (P.mirabilis,P.vulgaris )(25.4%),and P.aeruginosa (13.4%).Both gram positive and negative bac-teria isolated from ear infections showed low resistance rates to most antimicrobial agents tested.Overall ceftri-axone and ciprofloxacin were the most effective drugs when compared to other drugs tested against the gram-positive and gram-negative bacteria.Conclusion:Otitis media was the most common clinical finding in pa-tients with ear infection.With discharging ear,the gram-negative bacteria were the predominant isolates.The susceptibility pattern of isolates from the study showed that ceftriaxone,ciprofloxacin and gentamicin were the most effective drugs.It is recommended that treatment of ear infections should be based on culture and sensi-tivity at the study sites.Therefore,efforts should be directed towards early diagnosis and treatment of acute ear infection and continued re-evaluation of the resistant patterns of organisms to optimize treatments and reduce complications.

  10. A Myo6 mutation destroys coordination between the myosin heads, revealing new functions of myosin VI in the stereocilia of mammalian inner ear hair cells.

    Ronna Hertzano


    Full Text Available Myosin VI, found in organisms from Caenorhabditis elegans to humans, is essential for auditory and vestibular function in mammals, since genetic mutations lead to hearing impairment and vestibular dysfunction in both humans and mice. Here, we show that a missense mutation in this molecular motor in an ENU-generated mouse model, Tailchaser, disrupts myosin VI function. Structural changes in the Tailchaser hair bundles include mislocalization of the kinocilia and branching of stereocilia. Transfection of GFP-labeled myosin VI into epithelial cells and delivery of endocytic vesicles to the early endosome revealed that the mutant phenotype displays disrupted motor function. The actin-activated ATPase rates measured for the D179Y mutation are decreased, and indicate loss of coordination of the myosin VI heads or 'gating' in the dimer form. Proper coordination is required for walking processively along, or anchoring to, actin filaments, and is apparently destroyed by the proximity of the mutation to the nucleotide-binding pocket. This loss of myosin VI function may not allow myosin VI to transport its cargoes appropriately at the base and within the stereocilia, or to anchor the membrane of stereocilia to actin filaments via its cargos, both of which lead to structural changes in the stereocilia of myosin VI-impaired hair cells, and ultimately leading to deafness.

  11. Microbiomes of the normal middle ear and ears with chronic otitis media.

    Minami, Shujiro B; Mutai, Hideki; Suzuki, Tomoko; Horii, Arata; Oishi, Naoki; Wasano, Koichiro; Katsura, Motoyasu; Tanaka, Fujinobu; Takiguchi, Tetsuya; Fujii, Masato; Kaga, Kimitaka


    The aim of this study was to profile and compare the middle ear microbiomes of human subjects with and without chronic otitis media. Prospective multicenter cohort study. All consecutive patients undergoing tympanoplasty surgery for chronic otitis media or ear surgery for conditions other than otitis media were recruited. Sterile swab samples were collected from the middle ear mucosa during surgery. The variable region 4 of the 16S rRNA gene in each sample were amplified using region-specific primers adapted for the Illumina MiSeq sequencer (Illumina, CA, USA)). The sequences were subjected to local blast and classified using Metagenome@KIN (World Fusion, Tokyo, Japan). In total, 155 participants were recruited from seven medical centers. Of these, 88 and 67 had chronic otitis media and normal middle ears, respectively. The most abundant bacterial phyla on the mucosal surfaces of the normal middle ears were Proteobacteria, followed by Actinobacteria, Firmicutes, and Bacteroidetes. The children and adults with normal middle ears differed significantly in terms of middle ear microbiomes. Subjects with chronic otitis media without active inflammation (dry ear) had similar middle ear microbiomes as the normal middle ears group. Subjects with chronic otitis media with active inflammation (wet ear) had a lower prevalence of Proteobacteria and a higher prevalence of Firmicutes than the normal middle ears. The human middle ear is inhabited by more diverse microbial communities than was previously thought. Alteration of the middle ear microbiome may contribute to the pathogenesis of chronic otitis media with active inflammation. 2b. Laryngoscope, 127:E371-E377, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  12. Simple ears - flexible behavior: Information processing in the moth auditory pathway

    Pfuhl, Gerit; Kalinova, Blanka; Valterova, Irena; Berg, Bente Gunnveig


    Published version, also available at journal’s home page Abstract Lepidoptera evolved tympanic ears in response to echolocating bats. Comparative studies have shown that moth ears evolved many times independently from chordotonal organs. With only 1 to 4 receptor cells, they are one of the simplest hearing organs. The small number of receptors does not imply simplicity, neither in behavior nor in the neural circuit. Behaviorally, the response to ultrasound is far from being a simp...

  13. Characteristics of laser-induced shock wave injury to the inner ear of rats

    Kurioka, Takaomi; Matsunobu, Takeshi; Niwa, Katsuki; Tamura, Atsushi; Kawauchi, Satoko; Satoh, Yasushi; Sato, Shunichi; Shiotani, Akihiro


    Recently, the number of blast injuries of the inner ear has increased in the general population. In blast-induced inner ear injury, a shock wave (SW) component in the blast wave is considered to play an important role in sensorineural hearing loss. However, the mechanisms by which an SW affects inner ear tissue remain largely unknown. We aimed to establish a new animal model for SW-induced inner ear injury by using laser-induced SWs (LISWs) on rats. The LISWs were generated by irradiating an elastic laser target with 694-nm nanosecond pulses of a ruby laser. After LISW application to the cochlea through bone conduction, auditory measurements revealed the presence of inner ear dysfunction, the extent of which depended on LISW overpressure. A significantly lower survival rate of hair cells and spiral ganglion neurons, as well as severe oxidative damage, were observed in the inner ear exposed to an LISW. Although considerable differences in the pressure characteristics exist between LISWs and SWs in real blast waves, the functional and morphological changes shown by the present LISW-based model were similar to those observed in real blast-induced injury. Thus, our animal model is expected to be useful for laboratory-based research of blast-induced inner ear injury.

  14. The prostaglandin E2/EP4 receptor/cyclic AMP/T-type Ca(2+) channel pathway mediates neuritogenesis in sensory neuron-like ND7/23 cells.

    Mitani, Kenji; Sekiguchi, Fumiko; Maeda, Takashi; Tanaka, Yukari; Yoshida, Shigeru; Kawabata, Atsufumi


    We investigated mechanisms for the neuritogenesis caused by prostaglandin E2 (PGE2) or intracellular cyclic AMP (cAMP) in sensory neuron-like ND7/23 cells. PGE2 caused neuritogenesis, an effect abolished by an EP4 receptor antagonist or inhibitors of adenylyl cyclase (AC) or protein kinase A (PKA) and mimicked by the AC activator forskolin, dibutyryl cAMP (db-cAMP), and selective activators of PKA or Epac. ND7/23 cells expressed both Cav3.1 and Cav3.2 T-type Ca(2+) channels (T-channels). The neuritogenesis induced by db-cAMP or PGE2 was abolished by T-channel blockers. T-channels were functionally upregulated by db-cAMP. The PGE2/EP4/cAMP/T-channel pathway thus appears to mediate neuritogenesis in sensory neurons.

  15. Novel in vivo imaging analysis of an inner ear drug delivery system: Drug availability in inner ear following different dose of systemic drug injections.

    Kanzaki, Sho; Watanabe, Kotaro; Fujioka, Masato; Shibata, Shinsuke; Nakamura, Masaya; Okano, Hirotaka James; Okano, Hideyuki; Ogawa, Kaoru


    Systemic application of drugs is commonly used in clinical situations. Some of these drugs are ototoxic. Since there are few studies on in vivo monitoring of drug delivery dynamics, the time course or bioavailability of drugs in the inner ear of live animals following systemic drug application remains unknown. For instance, it is unknown whether the volume of a drug delivered systemically correlates with its inner ear pharmacokinetics. We previously established a new in vivo imaging system to monitor drug delivery in live mice. In the present study, we used this system to compare drug concentration in the inner ear over time after systemic drug injections. We used transgenic GFAP-Luc mice that harbor a firefly luciferase gene expression cassette regulated by 12 kb of murine GFAP promoter and human beta-globin intron 2. Luciferin delivered into the inner ear of these mice reacts with luciferase, and the resulting signals are detected in GFAP-expressing cells in the cochlear nerve. Thus, we assessed in the inner ear the intensity and duration of luciferin/luciferase signals after systemic injections of different volumes of luciferin. An IVIS(®) imaging system was used to observe signals, and these signals were compared to the drug dynamics of luciferin delivered through subcutaneous (sc) injections. The volume of sc-injected drug correlated significantly with photon counts measured in the inner ear. Photons were detected almost immediately after injection, peaking 20 min after injection. Drug concentration did not affect inner ear signals. Luciferin injected systemically appeared in the inner ear between highest and lowest concentration. Drug volume is an important parameter to know if the inner ear requires a higher level of the drug. We observed that it is the volume of a drug-not its concentration-that is the important factor. Indeed, the more volume of a drug injected systemically increased the concentration of that drug in the inner ear. This study provides a

  16. Core collapse supernova remnants with ears

    Grichener, Aldana


    We study the morphologies of core collapse supernova remnants (CCSNRs) and find that about third of CCSNRs have two opposite `ears' protruding from their main shell, and that the typical energy that is required to inflate these ears is about 10 percents of the explosion kinetic energy. We argue that these properties are most compatible with the expectation from the explosion jet feedback mechanism (JFM). Based on previous studies of ears in CCSNRs and the similarity of some ears to those found in planetary nebulae, we assume that the ears are inflated by jets that are launched during the explosion, or a short time after it. In the JFM explosion process the last jets' launching episode takes place just after the core has been ejected. These jets expand freely, interact with the exploding gas at some distance from the center, and form the ears. Under simple geometrical assumptions we find that the extra kinetic energy of the ears is in the range of 1 to 10 percents of the explosion energy. As not all of the kin...

  17. Manganese is toxic to spiral ganglion neurons and hair cells in vitro.

    Ding, Dalian; Roth, Jerome; Salvi, Richard


    Occupational exposure to high atmospheric levels of Mn produces a severe and debilitating disorder known as manganism characterized by extrapyramidal disturbances similar to that seen in Parkinson's disease. Epidemiological and case studies suggest that persistent exposures to Mn may have deleterious effects on other organs including the auditory system and hearing. Mn accumulates in the inner ear following acute exposure raising the possibility that it can damage the sensory hair cells that convert sound into neural activity or spiral ganglion neurons (SGN) that transmit acoustic information from the hair cells to the brain via the auditory nerve. In this paper we demonstrate for first time that Mn causes significant damage to the sensory hair cells, peripheral auditory nerve fibers (ANF) and SGN in cochlear organotypic cultures isolated from postnatal day three rats. The peripheral ANF that make synaptic contact with the sensory hair cells were particularly vulnerable to Mn toxicity; damage occurred at concentrations as low 0.01 mM and increased with dose and duration of Mn exposure. Sensory hair cells, in contrast, were slightly more resistant to Mn toxicity than the ANF. Mn induced an atypical pattern of sensory cell damage; Mn was more toxic to inner hair cells (IHC) than outer hair cells (OHC) and in addition, IHC loss was relatively uniform along the length of the cochlea. Mn also caused significant loss and shrinkage of SGN soma. These findings are the first to demonstrate that Mn can produce severe lesions to both neurons and hair cells in the postnatal inner ear.

  18. Imaging of the postoperative middle ear

    Williams, Marc T. [Department of Medical Imaging, Fondation Ophtalmologique Adolphe de Rothschild, 25 rue Manin, 75940, Paris (France); Ayache, Denis [Department of Otorhinolaryngology, Fondation Ophtalmologique Adolphe de Rothschild, Paris (France)


    The aim of this article is twofold: (a) to present the principles and the indications of surgical treatment of middle ear pathologies; and (b) to review the imaging findings after middle ear surgery, including the normal postoperative aspects and imaging findings in patients presenting with unsatisfactory surgical results or with suspicion of postoperative complications. This review is intentionally restricted to the most common diseases involving the middle ear: chronic otitis media and otosclerosis. In these specific fields of interest, CT and MR imaging play a very important role in the postoperative follow-up and in the work-up of surgical failures and complications. (orig.)

  19. [Ear keloid and clinical research progress].

    Du, Guangyuan; Zhu, Jiang


    Keloid refers to the damaged skin due to excessive fibroblast proliferation. Ear is one predilection site. The pathogenesis of ear keloid is not very clear, and the treatment is also varied. Surgery, postoperative radiotherapy and laser treatment, steroid hormones, pressure therapy are the basic treatment methods. Integrated application of a variety of treatments, classification research and new materials using revealed the prospect for the treatment of the disease. This thesis reviews literature about ear keloid in recent 10 years, and introduces this disease and clinical research progress.

  20. Surgical Management of Ear Diseases in Rabbits.

    Csomos, Rebecca; Bosscher, Georgia; Mans, Christoph; Hardie, Robert


    Otitis externa and media are frequently diagnosed disorders in rabbits and are particularly common in lop-eared breeds because of the specific anatomy of the ear canal. Medical management for otitis externa and media often provides only a temporary improvement in clinical signs. Surgery by means of partial or total ear canal ablation (PECA or TECA) combined with lateral bulla osteotomy (LBO) represents a feasible approach that is well tolerated and provides a good clinical outcome. Short-term complications associated with PECA/TECA-LBO include facial nerve paralysis and vestibular disease.

  1. Shaping magnetic fields to direct therapy to ears and eyes.

    Shapiro, B; Kulkarni, S; Nacev, A; Sarwar, A; Preciado, D; Depireux, D A


    Magnetic fields have the potential to noninvasively direct and focus therapy to disease targets. External magnets can apply forces on drug-coated magnetic nanoparticles, or on living cells that contain particles, and can be used to manipulate them in vivo. Significant progress has been made in developing and testing safe and therapeutic magnetic constructs that can be manipulated by magnetic fields. However, we do not yet have the magnet systems that can then direct those constructs to the right places, in vivo, over human patient distances. We do not yet know where to put the external magnets, how to shape them, or when to turn them on and off to direct particles or magnetized cells-in blood, through tissue, and across barriers-to disease locations. In this article, we consider ear and eye disease targets. Ear and eye targets are too deep and complex to be targeted by a single external magnet, but they are shallow enough that a combination of magnets may be able to direct therapy to them. We focus on how magnetic fields should be shaped (in space and time) to direct magnetic constructs to ear and eye targets.

  2. Femtosecond laser microstructuring of titanium surfaces for middle ear ossicular replacement prosthesis: results of preliminary studies

    Biedron, S.; Ilgner, J. F. R.; Fadeeva, E.; Chichkov, B.; Prescher, A.; Bovi, M.; Westhofen, M.


    The objective of this study was to optimize titanium surfaces by means of Ti:Sapphire femtosecond laser to improve the attachment of human cartilage cells on titanium prosthesis in middle ear surgery. The application of microstructures on titanium samples was evaluated and the influence of these microstructures on human auricular chondrocytes was studied in-vitro. After establishing the ear chondrocyte cell culture, cells were seeded on titanium platelets with selected microstructure patterns. Whereas the phenotype of cells seeded on unstructured titanium was similar to cells grown on standard tissue culture surfaces, the morphology of chondrocytes grown on structured titanium samples was influenced by the pattern. For future titanium middle ear prosthesis structural optimizations will be developed to promote chondrocyte growth and adhesion while impeding fibrocyte proliferation to avoid scarring on implant interfaces.

  3. Injuries of the external ear.

    Templer, J; Renner, G J


    Ear injuries occur in people of all ages but predominate in active people such as wrestlers, boxers, and bike riders. The types and extent of injury are a function of the force causing the injury. Shearing forces of moderate intensity cause hematoma formation, whereas greater force causes lacerations or even amputation. Sharp objects cause lacerations determined by the force, direction, and point of impact. The high ratio of surface area to mass makes the auricle vulnerable to extremes of temperature. People participating in high-risk activities should wear protective headgear. The goal of treatment is to restore the normal contours while preventing infection. Hematoma results in disfigurement by organization or chondritis. Evacuation and pressure dressings using sterile technique correct the condition. Second-degree burns are treated by regular cleansing and application of topical antimicrobials. Deeper burns require debridement, biologic dressings, or burying the cartilage subcutaneously for later reconstruction. Simple lacerations are closed under aseptic technique using either skin-to-skin sutures only or sutures of the skin combined with intercartilage sutures. Extensive and complex lacerations require meticulous care to match all fragments and prevent infection or loss of tissue. Bare cartilage must be covered with vascularized tissue. The treatment of total amputation is controversial. Some advocate reattachment as a composite graft using intravenous low molecular weight dextrans and heparin as adjuvants. Mladick dermabrades the amputated pinna, reattaches it with sutures, and then slips it into a pocket of elevated postauricular skin for 2 weeks. Others urge microvascular reanastomosis of the small nutrient vessels. Brent and Byrd separate the cartilage from its overlying skin and envelope it first with vascularized temporoparietal fascia and then a split-thickness skin graft. Chondritis is the most feared complication of injury or surgery of the pinna. It

  4. Erythropoietin and erythropoietin receptor expression in the guinea pig inner ear

    Cayé-Thomasen, Per; Wagner, Niels; Lidegaard Frederiksen, Birgitte


    The erythropoietin receptor (EPOR) is expressed in the brain and erythropoietin (EPO) has been shown to have neurotrophic and neuroprotective functions in the central nervous system and in the retina. These findings may be applied to the inner ear, pending EPO receptor presence. Accordingly......, this study determines expression of EPO and EPOR in the inner ear of the guinea pig. Normal guinea pig inner ears were processed for immunohistochemistry, using poly-clonal antibodies against EPO and the EPO receptor. EPO expression was exclusively found in most, but not all spiral ganglion neurons...... expressed by several cell types within the guinea pig cochlea. We hypothesize on the existence of a local paracrine system and that EPO treatment may be feasible following inner ear damage....

  5. Influence of fossoriality on inner ear morphology: insights from caecilian amphibians.

    Maddin, Hillary C; Sherratt, Emma


    It is widely accepted that a relationship exists between inner ear morphology and functional aspects of an animal's biology, such as locomotor behaviour. Animals that engage in agile and spatially complex behaviours possess semicircular canals that morphologically maximise sensitivity to correspondingly complex physical stimuli. Stemming from the prediction that fossorial tetrapods require a well-developed sense of spatial awareness, we investigate the hypothesis that fossoriality leads to inner ear morphology that is convergent with other spatially adept tetrapods. We apply morphometrics to otic capsule endocasts of 26 caecilian species to quantify aspects of inner ear shape, and compare these with a sample of frog and salamander species. Our results reveal caecilians (and also frogs) possess strongly curved canals, a feature in common with spatially adept species. However, significantly shorter canals in caecilians suggest reduced sensitivity, possibly associated with reduced reliance on vestibulo-ocular reflexes in this group of visually degenerate tetrapods. An elaboration of the sacculus of caecilians is interpreted as a unique adaptation among amphibians to increase sensitivity to substrate-borne vibrations transmitted through the head. This study represents the first quantitative analyses of inner ear morphology of limbless fossorial tetrapods, and identifies features within a new behavioural context that will contribute to our understanding of the biological consequences of physical stimuli on sensory function and associated morphological evolution.

  6. Some Remarks on Imaging of the Inner Ear: Options and Limitations.

    Giesemann, A; Hofmann, E


    The temporal bone has a highly complex anatomical structure, in which the sensory organs of the cochlea and the vestibular system are contained within a small space together with the sound-conducting system of the middle ear. Detailed imaging is thus required in this anatomical area. There are a great many clinical aims for which the highest-possible spatial resolution is required. These include the localization of cerebrospinal fluid fistulas, the detection of malformations of the middle and inner ear and the vestibulocochlear nerve, an aberrant course of the facial nerve and anomalies of the arterial and venous structures, the confirmation of dehiscence of the semicircular canals and finally, the verification of endolymphatic hydrops in cases of Ménière's disease. However, the term 'high resolution' is very time dependent. Two milestones in this respect have been (in 1991) the 3D visualization of the inner ear by means of maximum-intensity projection (MIP) of a T2-weighted constructive interference in steady state (CISS) sequence of a 1.5-tesla magnetic resonance imaging (MRI) scanner (Tanioka et al., Radiology 178:141-144, 1991) and (in 1997) imaging of the vestibulocochlear nerve for the diagnosis of hypoplasia inside the internal auditory canal using the same sequence (Casselman et al., Radiology 202:773-781, 1997).The objective of this article is to highlight the options for, and the challenges of, contemporary imaging with regard to some clinical issues relating to the inner ear.

  7. Hair cell-like cells generation induced by nature culture of cochlear sensory epithelia in rat%小鼠耳蜗感觉上皮细胞的自然培养诱导毛细胞的产生

    刘晖; 李胜利; 朱宏亮; 姚小宝; 王晓侠


    Object To establish rat auditory epithelial cell culture and try to find precursor cells of auditory hair cells in vitro and apply them to study mammalian hair cell regeneration.Methods With refinement of culture media and techniques,cochlear sensory epithelial cells of rat were cultured.Immunocytochemistry and Bromodeoxyuridine(BrdU)labeling were used to detect properties and mitotic status of cultured cells.Results The cultured auditory epithelial cells showed a large,flat epithelial morphotype and expressed F-actin and cytokerafin,a subset of cells generated from auditory epithelium were labeled by calretinin, a specific marker of early hair cell.The appearance of calretinin-positive cells were also confirmed in 3rd passage culture by immunostaining.Conclusions Postnatal rat auditory epithelium can be induced to generate hair cell-like cells by nature culture,this phenomenon suggested thatprogenitor cells may exist in rat cochlea and they may give birth to new hair cells. Whether these progenitor cells are tissue specific stem cells was still need more study.%目的培养小鼠耳蜗上皮细胞,寻找听觉毛细胞的前体细胞,从而研究听觉毛细胞的再生.方法改良细胞培养基和培养技术,建立小鼠耳蜗听觉上皮细胞的培养;用免疫细胞化学方法和BrdU标记法检测培养细胞的性质和分裂状态.结果培养的听觉上皮细胞表现为大而扁平的上皮细胞形态,并且表达上皮细胞的标志F-actin和cytokeratin,部分新生的细胞可被早期毛细胞的特异标志calretinin着染,表明有听毛细胞样的细胞产生.这种现象经3次传代培养后仍然存在.结论自然细胞培养方法可能诱导小鼠听觉毛细胞的产生,在小鼠的耳蜗内可能存在听觉毛细胞的前体细胞,而这些前体细胞是否是组织特异性干细胞还需要更进一步的研究.

  8. [Pathophysiology of sensory ataxic neuropathy].

    Sobue, G


    The main lesions of sensory ataxic neuropathy such as chronic idiopathic sensory ataxic neuropathy, (ISAN), carcinomatous neuropathy, Sjögren syndrome-associated neuropathy and acute autonomic and sensory neuropathy (AASN) are the large-diameter sensory neurons and dosal column of the spinal cord and the large myelinated fibers in the peripheral nerve trunks. In addition, afferent fibers to the Clarke's nuclei are also severely involved, suggesting Ia fibers being involved in these neuropathies. In NT-3 knockout mouse, an animal model of sensory ataxia, large-sized la neurons as well as muscle spindle and Golgi tendon organs are depleted, and are causative for sensory ataxia. Thus, the proprioceptive Ia neurons would play a role in pathogenesis of sensory ataxia in human sensory ataxic neuropathies, but the significance of dorsal column involvement in human sensory ataxia is still needed to evaluate.

  9. The novel mouse mutant, chuzhoi, has disruption of Ptk7 protein and exhibits defects in neural tube, heart and lung development and abnormal planar cell polarity in the ear

    Paudyal Anju


    Full Text Available Abstract Background The planar cell polarity (PCP signalling pathway is fundamental to a number of key developmental events, including initiation of neural tube closure. Disruption of the PCP pathway causes the severe neural tube defect of craniorachischisis, in which almost the entire brain and spinal cord fails to close. Identification of mouse mutants with craniorachischisis has proven a powerful way of identifying molecules that are components or regulators of the PCP pathway. In addition, identification of an allelic series of mutants, including hypomorphs and neomorphs in addition to complete nulls, can provide novel genetic tools to help elucidate the function of the PCP proteins. Results We report the identification of a new N-ethyl-N-nitrosourea (ENU-induced mutant with craniorachischisis, which we have named chuzhoi (chz. We demonstrate that chuzhoi mutant embryos fail to undergo initiation of neural tube closure, and have characteristics consistent with defective convergent extension. These characteristics include a broadened midline and reduced rate of increase of their length-to-width ratio. In addition, we demonstrate disruption in the orientation of outer hair cells in the inner ear, and defects in heart and lung development in chuzhoi mutants. We demonstrate a genetic interaction between chuzhoi mutants and both Vangl2Lp and Celsr1Crsh mutants, strengthening the hypothesis that chuzhoi is involved in regulating the PCP pathway. We demonstrate that chuzhoi maps to Chromosome 17 and carries a splice site mutation in Ptk7. This mutation results in the insertion of three amino acids into the Ptk7 protein and causes disruption of Ptk7 protein expression in chuzhoi mutants. Conclusions The chuzhoi mutant provides an additional genetic resource to help investigate the developmental basis of several congenital abnormalities including neural tube, heart and lung defects and their relationship to disruption of PCP. The chuzhoi mutation

  10. Evolution: Fossil Ears and Underwater Sonar.

    Lambert, Olivier


    A key innovation in the history of whales was the evolution of a sonar system together with high-frequency hearing. Fossils of an archaic toothed whale's inner ear bones provide clues for a stepwise emergence of underwater echolocation ability.

  11. Ear Infection Treatment: Do Alternative Therapies Work?

    ... in books and magazines. They include chiropractic adjustments, homeopathy, herbal eardrops and others. Perhaps you're seeking ... infection treatments have been studied with mixed results. Homeopathy. A controversial treatment for ear infection, homeopathy involves ...

  12. Superglue accidentally used as ear drops

    Anusha, Bala; Purushotman, R; Lina, L C; Avatar, S


    Superglue in the ear as a foreign body is an uncommon presentation. We report the case of a lady who accidentally instilled superglue directly onto her tympanic membrane and presented five days later...

  13. Why do elephants flap their ears?

    the elephant's ears serve as an important heat-regulating mechanism is not ... thermocouples; the cleaned vessel surface temperature was considered adequate .... The pathways for this transfer must be largely convective and evaporative.

  14. Inner ear malformations: a practical diagnostic approach.

    Mazón, M; Pont, E; Montoya-Filardi, A; Carreres-Polo, J; Más-Estellés, F

    Pediatric sensorineural hearing loss is a major cause of disability; although inner ear malformations account for only 20-40% of all cases, recognition and characterization will be vital for the proper management of these patients. In this article relevant anatomy and development of inner ear are surveyed. The role of neuroimaging in pediatric sensorineural hearing loss and cochlear preimplantation study are assessed. The need for a universal system of classification of inner ear malformations with therapeutic and prognostic implications is highlighted. And finally, the radiological findings of each type of malformation are concisely described and depicted. Computed tomography and magnetic resonance imaging play a crucial role in the characterization of inner ear malformations and allow the assessment of the anatomical structures that enable the selection of appropriate treatment and surgical approach. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Female Climacteric Syndrome Treated by Ear Embedding



    @@ Female climacteric syndrome is a common disease occurring before and after menopause. The author has treated the disease with ear embedding therapy, and achieved satisfactory therapeutic results. The following is a report of the clinical observation.

  16. Neonatal Ear Molding: Timing and Technique.

    Anstadt, Erin Elizabeth; Johns, Dana Nicole; Kwok, Alvin Chi-Ming; Siddiqi, Faizi; Gociman, Barbu


    The incidence of auricular deformities is believed to be ∼11.5 per 10,000 births, excluding children with microtia. Although not life-threatening, auricular deformities can cause undue distress for patients and their families. Although surgical procedures have traditionally been used to reconstruct congenital auricular deformities, ear molding has been gaining acceptance as an efficacious, noninvasive alternative for the treatment of newborns with ear deformations. We present the successful correction of bilateral Stahl's ear deformity in a newborn through a straightforward, nonsurgical method implemented on the first day of life. The aim of this report is to make pediatric practitioners aware of an effective and simple molding technique appropriate for correction of congenital auricular anomalies. In addition, it stresses the importance of very early initiation of ear cartilage molding for achieving the desired outcome.

  17. Mozart ear: diagnosis, treatment, and literature review.

    Yamashita, Ken; Yotsuyanagi, Takatoshi; Saito, Tamotsu; Isogai, Noritaka; Mori, Hiromasa; Itani, Yoshihito


    Mozart ear is a congenital auricular deformity, which is mainly characterized by a bulging appearance of the anterosuperior portion of the auricle, a convexly protruded cavum conchae, and a slit-like narrowing of the orifice of the external auditory meatus. It is said to be uncommon, and because no one has yet fully described neither the disease nor the treatment, the concept of Mozart ear has not been unified. This report describes a case of a 13-year-old girl presented with an unusual congenital deformity which showed the features of Mozart ear. It is an extremely rare deformity that only about 4 clinical cases have been reported in medical literature thereby a treatment method has not been fully discussed. For surgical correction of our cases, we excised deformed conchal cartilage, turned it over, regrafted, and maintained a cosmetically positive result. We also reviewed and described the origin, current concept, and treatment method of Mozart ear.

  18. Environment for Auditory Research Facility (EAR)

    Federal Laboratory Consortium — EAR is an auditory perception and communication research center enabling state-of-the-art simulation of various indoor and outdoor acoustic environments. The heart...

  19. Association of microRNA 146 with middle ear hyperplasia in pediatric otitis media.

    Samuels, Tina L; Yan, Justin; Khampang, Pawjai; MacKinnon, Alexander; Hong, Wenzhou; Johnston, Nikki; Kerschner, Joseph E


    Toll-like receptor signaling activated by bacterial otitis media pathogens in the middle ear has been shown to play a key role in OM susceptibility, pathogenesis and recovery. Recent studies implicate microRNA 146 (miR-146) in regulation of inflammation via negative feedback of toll-like receptor signaling (TLR) in a wide variety of tissues, however its involvement in otitis media is unknown. Human middle ear epithelial cells were stimulated with proinflammatory cytokines, interleukin 1 beta or tumor necrosis factor alpha, for two to twenty-four hours. Middle ear biopsies were collected from children with otitis media with effusion (n = 20), recurrent otitis media (n = 9), and control subjects undergoing cochlear implantation (n = 10). miR-146a, miR-146b expression was assayed by quantitative PCR (qPCR). Expression of miR-146 targets involved in TLR signaling, IRAK1 and TRAF6, was assayed by qPCR in middle ear biopsies. Middle ear biopsies were cryosectioned and epithelial thickness measured by a certified pathologist. Proinflammatory cytokines induced expression of miR-146 in middle ear epithelial cells in vitro. Middle ear miR-146a and miR-146b expression was elevated in otitis media patients relative to control subjects and correlated with middle ear epithelial thickness. A trend towards inverse correlation was observed between miR-146 and TRAF6 expression in the clinical population. This report is the first to assess miRNA expression in a clinical population with OM. Findings herein suggest miR-146 may play a role in OM. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. 21 CFR 874.3430 - Middle ear mold.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Middle ear mold. 874.3430 Section 874.3430 Food... DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3430 Middle ear mold. (a) Identification. A middle ear mold is a preformed device that is intended to be implanted to reconstruct the middle...

  1. 21 CFR 874.4140 - Ear, nose, and throat bur.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear, nose, and throat bur. 874.4140 Section 874...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4140 Ear, nose, and throat bur. (a) Identification. An ear, nose, and throat bur is a device consisting of an interchangeable drill bit that...

  2. 38 CFR 4.87 - Schedule of ratings-ear.


    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Schedule of ratings-ear...—ear. Diseases of the Ear Rating 6200Chronic suppurative otitis media, mastoiditis, or cholesteatoma... of the substance 10 6208Malignant neoplasm of the ear (other than skin only) 100 Note: A rating...

  3. Cryptogenic sensory polyneuropathy.

    Pasnoor, Mamatha; Dimachkie, Mazen M; Barohn, Richard J


    Chronic sensory or sensorimotor polyneuropathy is a common cause for referral to neurologists. Despite extensive diagnostic testing, up to one-third of these patients remain without a known cause, and are referred to as having cryptogenic sensory peripheral neuropathy. Symptoms progress slowly. On examination, there may be additional mild toe flexion and extension weakness. Electrophysiologic testing and histology reveals axonal neuropathy. Prognosis is usually favorable, as most patients maintain independent ambulation. Besides patient education and reassurance, management is focused on pharmacotherapy for neuropathic pain and physical therapy for balance training, and, occasionally, assistive devices.

  4. Commissioning of n_TOF EAR2

    The construction of the second beam line and experiment area (EAR2) of the n_TOF facility is currently ongoing and scheduled to be completed by July 2014. An extensive series of measurements is planned in order to determine the beam characteristics like the neutron flux, the spatial beam profile and the resolution function, as well as the response of several detectors considered for use in future measurements at EAR2. A rigorous study of backgrounds will be undertaken in various conditions.

  5. Osteoma of the middle ear: case report

    Ryu, Ji Hwa [College of Medicine, Inje University, Dongrae Paik Hospital, Busan (Korea, Republic of)


    Osteomas of the middle ear are exceedingly rare benign neoplasms. To date, only 21 cases have been reported in the literature. They arise from the promontory, the pyramidal process and the ossicles, and they are usually asymptomatic or cause some conductive hearing loss. We report here the CT and pathologic findings in a 38-year-old woman with a benign osteoma of the middle ear along with chronic otitis media.

  6. Hearing impairment and ear pathology in Nepal.

    Little, P; Bridges, A; Guragain, R; Friedman, D; Prasad, R; Weir, N


    A stratified random cluster sample of 15,845 subjects was performed in two regions of Nepal to determine the prevalence and main causes of hearing impairment (the most common disability) and the prevalence of ear disease. Subjects reporting current ear pain, or ear discharge, or hearing impairment on direct questioning by a Nepali health worker (primary screening failed), had otoscopy and audiometry (using the Liverpool Field Audiometer) performed, and a questionnaire administered relating to past history. In every fifth house subjects who passed the primary screening (1,716 subjects) were examined to assess the false negative rate of screening. An estimated 16.6 per cent of the study population have hearing impairment (either ear worse than 30 dB hearing threshold level (HTL) 1.0-4.0 kHz, or 50 dB HTL 0.5 kHz), and 7.4 per cent ear drum pathology, equivalent to respectively 2.71 and 1.48 million people extrapolated to the whole of Nepal. Most hearing impairment in the school age group (55.2 per cent) is associated with otitis media or its sequelae. Probably at least 14 per cent of sensorineural deafness is preventable (7 per cent infectious disease, 3.9 per cent trauma, 0.8 per cent noise exposure, 1 per cent cretinism, and 1 per cent abnormal pregnancy or labour). Most individuals reporting current ear pathology (61 per cent) had never attended a health post, and of those receiving ear drop treatment, 84 per cent still had serious pathology. Of subjects who reported ear drop treatment at any time, 31 per cent still had serious pathology. The use of traditional remedies was prevalent.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Ear-to-Ear On-Body Channel Fading in the ISM-band for Tangentially-Polarized Antennas

    Kvist, Søren Helstrup; Thaysen, Jesper; Jakobsen, Kaj Bjarne


    The ear-to-ear on-body channel fading has been studied in the ISM-band. The ear-to-ear path gain was measured on six persons in an indoor environment for a duration of 200 s. The channel fading has been characterized in terms of empirical cumulative distribution functions (CDF), average fade...

  8. Radiation effect on the middle ear of the guinea pig

    Harada, Hirofumi; Nishizawa, Shinji; Hiraide, Fumihisa; Inoue, Tetsuzo


    It is known that radiation therapy of the head and neck causes otitis media with effusion. Otitis media with effusion was induced in guinea pigs by cobalt-60 irradiation. Twenty guinea pigs with intact drum and normal Preyer reflex were used. The animals were irradiated with doses of 2,000 rad, 4,000 rad, and 6,000 rad. They were sacrificed seven days after the irradiation. Other animals were irradiated with doses of 4,000 rad and sacrificed one day, three days, seven days, and fourteen days after the irradiation. Vascular permeability of the middle ear mucosa was observed by Majno's vascular labelling technique. Pathological change of the middle ear was examined under the light microscope. Vascular permeability increased in three days after 4,000 rad irradiation and small vessels were labelled with carbon particles. Seven days after irradiation, carbon labelling of small vessels was more extensive and extravascular blackening was present in the adjacent tissues. Edematous change of the middle ear mucosa and metaplasia of the epithelial cells were also observed. New bone formation of the tympanic bulla was increased by repeated irradiations. (author).

  9. Transcendence and Sensoriness

    Protestant theology and culture are known for a reserved, at times skeptical, attitude to the use of art and aesthetic forms of expression in a religious context. In Transcendence and Sensoriness, this attitude is analysed and discussed both theoretically and through case studies considered...

  10. Novel in vivo imaging analysis of an inner ear drug delivery system in mice: comparison of inner ear drug concentrations over time after transtympanic and systemic injections.

    Sho Kanzaki

    Full Text Available OBJECTIVE: Systemic steroid injections are used to treat idiopathic sudden-onset sensorineural hearing loss (ISSHL and some inner ear disorders. Recent studies show that transtympanic (TT steroid injections are effective for treating ISSHL. As in vivo monitoring of drug delivery dynamics for inner ear is lacking, its time course and dispersion of drugs is unknown. Here, we used a new in vivo imaging system to monitor drug delivery in live mice and to compare drug concentrations over time after TT and systemic injections. METHODS: Luciferin delivered into the inner ears of GFAP-Luc transgenic mice reacted with luciferase in GFAP-expressing cells in the cochlear spiral ganglion, resulting in photon bioluminescence. We used the Xenogen IVIS® imaging system to measure how long photons continued to be emitted in the inner ear after TT or systemic injections of luciferin, and then compared the associated drug dynamics. RESULTS: The response to TT and IP injections differed significantly. Photons were detected five minutes after TT injection, peaking at ~20 minutes. By contrast, photons were first detected 30 minutes after i.p. injection. TT and i.p. drug delivery time differed considerably. With TT injections, photons were detected earlier than with IP injections. Photon bioluminescence also disappeared sooner. Delivery time varied with TT injections. CONCLUSIONS: We speculate that the drug might enter the Eustachian tube from the middle ear. We conclude that inner-ear drug concentration can be maintained longer if the two injection routes are combined. As the size of luciferin differs from that of therapeutics like dexamethasone, combining drugs with luciferin may advance our understanding of in vivo drug delivery dynamics in the inner ear.

  11. Sensory analysis of lipstick.

    Yap, K C S; Aminah, A


    Sensory analysis of lipstick product by trained panellists started with recruiting female panels who are lipstick users, in good health condition and willing to be a part of sensory members. This group of people was further scrutinized with duo-trio method using commercial lipstick samples that are commonly used among them. About 40% of the 15 panels recruited were unable to differentiate the lipstick samples they usually use better than chance. The balance of nine panels that were corrected at least with 65% across all trials in panels screening process was formed a working group to develop sensory languages as a means of describing product similarities and differences and a scoring system. Five sessions with each session took about 90 min were carried out using 10 types of lipsticks with different waxes mixture ratio in the formulation together with six commercial lipsticks that are the most common to the panels. First session was focus on listing out the panels' perception towards the characteristic of the lipstick samples after normal application on their lips. Second session was focus on the refining and categorizing the responses gathered from the first session and translated into sensory attributes with its definition. Third session was focus on the scoring system. Fourth and fifth sessions were repetition of the third session to ensure consistency. In a collective effort of the panels, sensory attributes developed for lipstick were Spreadability, Off flavour, Hardness, Smoothness, Moist, Not messy, Glossy and Greasy. Analysis of variance was able to provide ample evidence on gauging the panel performance. A proper panels selecting and training was able to produce a reliable and sensitive trained panel for evaluating the product based on the procedures being trained. © 2011 The Authors. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  12. Antibodies mediate formation of neutrophil extracellular traps in the middle ear and facilitate secondary pneumococcal otitis media.

    Short, Kirsty R; von Köckritz-Blickwede, Maren; Langereis, Jeroen D; Chew, Keng Yih; Job, Emma R; Armitage, Charles W; Hatcher, Brandon; Fujihashi, Kohtaro; Reading, Patrick C; Hermans, Peter W; Wijburg, Odilia L; Diavatopoulos, Dimitri A


    Otitis media (OM) (a middle ear infection) is a common childhood illness that can leave some children with permanent hearing loss. OM can arise following infection with a variety of different pathogens, including a coinfection with influenza A virus (IAV) and Streptococcus pneumoniae (the pneumococcus). We and others have demonstrated that coinfection with IAV facilitates the replication of pneumococci in the middle ear. Specifically, we used a mouse model of OM to show that IAV facilitates the outgrowth of S. pneumoniae in the middle ear by inducing middle ear inflammation. Here, we seek to understand how the host inflammatory response facilitates bacterial outgrowth in the middle ear. Using B cell-deficient infant mice, we show that antibodies play a crucial role in facilitating pneumococcal replication. We subsequently show that this is due to antibody-dependent neutrophil extracellular trap (NET) formation in the middle ear, which, instead of clearing the infection, allows the bacteria to replicate. We further demonstrate the importance of these NETs as a potential therapeutic target through the transtympanic administration of a DNase, which effectively reduces the bacterial load in the middle ear. Taken together, these data provide novel insight into how pneumococci are able to replicate in the middle ear cavity and induce disease.

  13. Carcinoid Tumors in the Middle Ear: a Case Report and Literature Review

    WANG Entong; GONG Weixi; DA Jiping


    Middle ear carcinoid tumor (MEC T) is rare. Only 46 cases of MECT have been reported in the literature since the first case of MECT was described in 1980. We present here a case of primary MECT initially diagnosed as inflammatory aural polyp. The case was a 43-year-old women complaining of right ear chronic otorrhea and hearing loss over a period of five years, with a blockage sensation in the right ear for two years. Audiometry showed conductive hearing loss in the right ear. Physical examination and CT scans showed a mass in the right external auditory canal and middle ear, surrounding the ossicular chain. Pathologic study of surgically removed specimen revealed features of carcinoid tumor with positive staining to chromogranin A and synaptophysin in tumor cells. Local radiation of 60 Gy was applied. The patient has been followed up for more than one year. Postoperative histopathological examination showed no evidence of MECT recurrence one year after surgery, but inflammatory changes in the middle ear. Relevant literatures were reviewed. Clinical, histopathological, immunohistochemical and ultrastructural features of MECT, and strategies in MECT diagnosis and management are discussed.

  14. Supporting Cells-a New Area in Cochlear Physiology Study

    ZHAO Li-dong; LIU Jun; HU Yin-yan; SUN Jian-he; YANG Shi-ming


    For many years, studies about the cochlea have been mainly focused on sensory cells, i.e. the inner hair cell (IHC) and outer hair cell (OHC), and the neuron system. Supporting cells, such as Hensen's cells and Deiters' cells are less studied. Their physiological functions and other characteris-tics are not well documented. Nowadays, supporting cells are a new world attracting to scientists" inter-ests. The scope of this review is to detail the biological properties of the supporting cells, mainly Hensen's cells and Deiters' cells in the cochlea. Studies on this subject will be helpful in understanding physiology of the cochlea, and hopefully provide new approaches in treating diseases of inner ear.

  15. Structure and function of the mammalian middle ear. I: Large middle ears in small desert mammals.

    Mason, Matthew J


    Many species of small desert mammals are known to have expanded auditory bullae. The ears of gerbils and heteromyids have been well described, but much less is known about the middle ear anatomy of other desert mammals. In this study, the middle ears of three gerbils (Meriones, Desmodillus and Gerbillurus), two jerboas (Jaculus) and two sengis (elephant-shrews: Macroscelides and Elephantulus) were examined and compared, using micro-computed tomography and light microscopy. Middle ear cavity expansion has occurred in members of all three groups, apparently in association with an essentially 'freely mobile' ossicular morphology and the development of bony tubes for the middle ear arteries. Cavity expansion can occur in different ways, resulting in different subcavity patterns even between different species of gerbils. Having enlarged middle ear cavities aids low-frequency audition, and several adaptive advantages of low-frequency hearing to small desert mammals have been proposed. However, while Macroscelides was found here to have middle ear cavities so large that together they exceed brain volume, the bullae of Elephantulus are considerably smaller. Why middle ear cavities are enlarged in some desert species but not others remains unclear, but it may relate to microhabitat.

  16. Gain and maximum output of two electromagnetic middle ear implants: are real ear measurements helpful?

    Snik, A.F.M.; Noten, J.F.P.; Cremers, C.W.R.J.


    We compared the output of two electronic middle ear implants: the Otologics MET device and the Vibrant Soundbridge device. Both devices were programmed in the linear amplification mode. Aided minus unaided sound pressure levels recorded in the ear canal (objective gain) were compared to unaided minu

  17. Prenatal evaluation of the middle ear and diagnosis of middle ear hypoplasia using MRI

    Katorza, Eldad; Nahama-Allouche, Catherine; Ducou le Pointe, Hubert; Garel, Catherine [Hopital d' Enfants Armand-Trousseau, Service de Radiologie, Paris (France); Castaigne, Vanina [Hopital Saint-Antoine, Service de Gynecologie-Obstetrique, Paris (France); Gonzales, Marie; Marlin, Sandrine [Hopital d' Enfants Armand-Trousseau, Service de Genetique et Embryologie medicales, Paris (France); Galliani, Eva [Hopital d' Enfants Armand-Trousseau, Service de Chirurgie maxillo-faciale, Paris (France); Jouannic, Jean-Marie; Rosenblatt, Jonathan [Hopital d' Enfants Armand-Trousseau, Service de Gynecologie-Obstetrique, Centre pluridisciplinaire de diagnostic prenatal, Paris (France)


    Analysis of the middle ear with fetal MRI has not been previously reported. To show the contribution of fetal MRI to middle ear imaging. The tympanic cavity was evaluated in 108 fetal cerebral MRI examinations (facial and/or cerebral malformation excluded) and in two cases, one of Treacher Collins syndrome (case 1) and the other of oculo-auriculo-vertebral (OUV) spectrum (case 2) with middle ear hypoplasia identified by MRI at 27 and 36 weeks' gestation, respectively. In all 108 fetuses (mean gestational age 32.5 weeks), the tympanic cavity and T2 hypointensity related to the ossicles were well visualised on both sides. Case 1 had micro/retrognathia and bilateral external ear deformity and case 2 had retrognathism with a left low-set and deformed ear. MRI made it possible to recognize the marked hypoplasia of the tympanic cavity, which was bilateral in case 1 and unilateral in case 2. Both syndromes are characterized by craniofacial abnormalities including middle ear hypoplasia, which cannot be diagnosed with US. The middle ear cavity can be visualized with fetal MRI. We emphasize the use of this imaging modality in the diagnosis of middle ear hypoplasia. (orig.)

  18. Forward and reverse middle ear frequency responses with various terminal loads

    Thejane, T


    Full Text Available Introduction Hearing loss is a prevalent sensory impairment. Conductive hearing loss, which often results from external or middle ear disorders, can be better treated through a in depth un- derstanding of the mechanics of the hearing organ [1]. Mid- dle... model of the auditory periphery for speech and hear- ing research. i. ascending path,? J. Acoust. Soc. Am., vol. 95, pp. 331?342, 1994. [4] G. von Bekesy and W. A. Rosenblith, ?The early his- tory of hearing-observations and theories,? J.Acoust. Soc...

  19. Ocular, Ear and Renal Manifestations of Alport Syndrome in Three Iranian Families

    Mohammad Hossein Davari


    Full Text Available Alport syndrome is a genetic disorder of basement membranes caused by mutations in type IV collagen network. It was first identified by Dr. Alport in 1927. Its major clinical manifestations are included: glomerulopathy, sensory hearing loss, anterior lenticonus, and the prevalence of Alports’ gene in general population is about 1 in 5000 and the disease prevalence is 1 in 10000 [1-3]. Here we report ocular, ear and renal manifestations of Alport syndrome in 3 families that living in the east city of Iran, Birjand, and we have followed all of this family for 6 years so far.

  20. The simple ears of noctuoid moths are tuned to the calls of their sympatric bat community

    Ter Hofstede, Hannah M; Goerlitz, Holger R; Ratcliffe, John M


    Insects with bat-detecting ears are ideal animals for investigating sensory system adaptations to predator cues. Noctuid moths have two auditory receptors (A1 and A2) sensitive to the ultrasonic echolocation calls of insectivorous bats. Larger moths are detected at greater distances by bats than...... frequency of the less sensitive A2 receptor are also related to size, and that these relationships hold when controlling for evolutionary relationships. The slopes of best threshold vs. size differ, however, such that the difference in threshold between A1 and A2 is greater for larger than smaller moths...

  1. Phoenix is required for mechanosensory hair cell regeneration in the zebrafish lateral line.

    Behra, Martine; Bradsher, John; Sougrat, Rachid; Gallardo, Viviana; Allende, Miguel L; Burgess, Shawn M


    In humans, the absence or irreversible loss of hair cells, the sensory mechanoreceptors in the cochlea, accounts for a large majority of acquired and congenital hearing disorders. In the auditory and vestibular neuroepithelia of the inner ear, hair cells are accompanied by another cell type called supporting cells. This second cell population has been described as having stem cell-like properties, allowing efficient hair cell replacement during embryonic and larval/fetal development of all vertebrates. However, mammals lose their regenerative capacity in most inner ear neuroepithelia in postnatal life. Remarkably, reptiles, birds, amphibians, and fish are different in that they can regenerate hair cells throughout their lifespan. The lateral line in amphibians and in fish is an additional sensory organ, which is used to detect water movements and is comprised of neuroepithelial patches, called neuromasts. These are similar in ultra-structure to the inner ear's neuroepithelia and they share the expression of various molecular markers. We examined the regeneration process in hair cells of the lateral line of zebrafish larvae carrying a retroviral integration in a previously uncharacterized gene, phoenix (pho). Phoenix mutant larvae develop normally and display a morphologically intact lateral line. However, after ablation of hair cells with copper or neomycin, their regeneration in pho mutants is severely impaired. We show that proliferation in the supporting cells is strongly decreased after damage to hair cells and correlates with the reduction of newly formed hair cells in the regenerating phoenix mutant neuromasts. The retroviral integration linked to the phenotype is in a novel gene with no known homologs showing high expression in neuromast supporting cells. Whereas its role during early development of the lateral line remains to be addressed, in later larval stages phoenix defines a new class of proteins implicated in hair cell regeneration.

  2. Phoenix is required for mechanosensory hair cell regeneration in the zebrafish lateral line.

    Martine Behra


    Full Text Available In humans, the absence or irreversible loss of hair cells, the sensory mechanoreceptors in the cochlea, accounts for a large majority of acquired and congenital hearing disorders. In the auditory and vestibular neuroepithelia of the inner ear, hair cells are accompanied by another cell type called supporting cells. This second cell population has been described as having stem cell-like properties, allowing efficient hair cell replacement during embryonic and larval/fetal development of all vertebrates. However, mammals lose their regenerative capacity in most inner ear neuroepithelia in postnatal life. Remarkably, reptiles, birds, amphibians, and fish are different in that they can regenerate hair cells throughout their lifespan. The lateral line in amphibians and in fish is an additional sensory organ, which is used to detect water movements and is comprised of neuroepithelial patches, called neuromasts. These are similar in ultra-structure to the inner ear's neuroepithelia and they share the expression of various molecular markers. We examined the regeneration process in hair cells of the lateral line of zebrafish larvae carrying a retroviral integration in a previously uncharacterized gene, phoenix (pho. Phoenix mutant larvae develop normally and display a morphologically intact lateral line. However, after ablation of hair cells with copper or neomycin, their regeneration in pho mutants is severely impaired. We show that proliferation in the supporting cells is strongly decreased after damage to hair cells and correlates with the reduction of newly formed hair cells in the regenerating phoenix mutant neuromasts. The retroviral integration linked to the phenotype is in a novel gene with no known homologs showing high expression in neuromast supporting cells. Whereas its role during early development of the lateral line remains to be addressed, in later larval stages phoenix defines a new class of proteins implicated in hair cell regeneration.

  3. Epigenetic regulation in the inner ear and its potential roles in development, protection, and regeneration

    Jian eZuo


    Full Text Available The burgeoning field of epigenetics is beginning to make a significant impact on our understanding of tissue development, maintenance, and function. Epigenetic mechanisms regulate the structure and activity of the genome in response to intracellular and environmental cues that direct cell-type specific gene networks. The inner ear is comprised of highly specialized cell types with identical genomes that originate from a single totipotent zygote. During inner ear development specific combinations of transcription factors and epigenetic modifiers must function in a coordinated manner to establish and maintain cellular identity. These epigenetic regulatory mechanisms contribute to the maintenance of distinct chromatin states and cell-type specific gene expression patterns. In this review, we highlight emerging paradigms for epigenetic modifications related to inner ear development, and how epigenetics may have a significant role in hearing loss, protection, and regeneration.

  4. [Inner Ear Hearing Loss Part II: Sudden Sensorineural Hearing Loss, Therapeutic Options].

    Hesse, Gerhard


    The great majority of hearing disorders generates from pathologies in the inner ear, mainly the outer hair cells, as mentioned in the first part of this review. Very often, however, hearing loss appears suddenly and even without external causes like noise exposure. This sudden hearing loss is mostly unilateral, recovers very often spontaneously and should be treated, if persisting. Only in this acute stage there are therapeutic options available. If the inner ear hearing loss is chronic there is no curative therapy, an effective management of the hearing disorder is only possible through rehabilitation. This is due to the fact, that hair cells of all mammals, incl. humans, have no regenerative capacity and neither pharmaceutic agents nor other means can induce regeneration and recovery of hair cells. Even a gen-therapy is not available yet. In the second part of this review the main focus lies in sudden hearing loss and general therapeutic options for inner ear hearing loss.

  5. Understanding Sensory Integration. ERIC Digest.

    DiMatties, Marie E.; Sammons, Jennifer H.

    This brief paper summarizes what is known about sensory integration and sensory integration dysfunction (DSI). It outlines evaluation of DSI, treatment approaches, and implications for parents and teachers, including compensatory strategies for minimizing the impact of DSI on a child's life. Review of origins of sensory integration theory in the…

  6. Computational model of touch sensory cells (T Cells) of the leech: role of the afterhyperpolarization (AHP) in activity-dependent conduction failure.

    Cataldo, Enrico; Brunelli, Marcello; Byrne, John H; Av-Ron, Evyatar; Cai, Yidao; Baxter, Douglas A


    Bursts of spikes in T cells produce an AHP, which results from activation of a Na+/K+ pump and a Ca2+-dependent K+ current. Activity-dependent increases in the AHP are believed to induce conduction block of spikes in several regions of the neuron, which in turn, may decrease presynaptic invasion of spikes and thereby decrease transmitter release. To explore this possibility, we used the neurosimulator SNNAP to develop a multi-compartmental model of the T cell. The model incorporated empirical data that describe the geometry of the cell and activity-dependent changes of the AHP. Simulations indicated that at some branching points, activity-dependent increases of the AHP reduced the number of spikes transmitted from the minor receptive fields to the soma and beyond. More importantly, simulations also suggest that the AHP could modulate, under some circumstances, transmission from the soma to the synaptic terminals, suggesting that the AHP can regulate spike conduction within the presynaptic arborizations of the cell and could in principle contribute to the synaptic depression that is correlated with increases in the AHP.

  7. Passive and active middle ear implants

    Beutner, Dirk


    Full Text Available Besides eradication of chronic middle ear disease, the reconstruction of the sound conduction apparatus is a major goal of modern ear microsurgery. The material of choice in cases of partial ossicular replacement prosthesis is the autogenous ossicle. In the event of more extensive destruction of the ossicular chain diverse alloplastic materials, e.g. metals, ceramics, plastics or composits are used for total reconstruction. Their specialised role in conducting sound energy within a half-open implant bed sets high demands on the biocompatibility as well as the acoustic-mechanic properties of the prosthesis. Recently, sophisticated titanium middle ear implants allowing individual adaptation to anatomical variations are widely used for this procedure. However, despite modern developments, hearing restoration with passive implants often faces its limitations due to tubal-middle-ear dysfunction. Here, implantable hearing aids, successfully used in cases of sensorineural hearing loss, offer a promising alternative. This article reviews the actual state of affairs of passive and active middle ear implants.

  8. CT of temporal bone - IV. inner ear

    Kwon, Jae Yoon; Sung, Kyu Bo; Youn, Eun Kyoung; Park, Youn Kyeung; Lee, Young Uk [Koryo general Hospital, Seoul (Korea, Republic of)


    Temporal bone CT was done in 697 patients from April 1985 to October 1989. The abnormal findings were seen in 453 patients, which were chronic otitis media in 355 patients, fracture in 49 patients and congenital anomaly in 44 patients, etc. The abnormal findings of inner ear were observed on 46 patients. The results were summarized as follows : 1. The incidence of inner ear involvement by chronic otitis media was 7.3% (26/355 : labyrinthine fistula in 17 patients, labyrinthitis ossificans in 9 patients). Labyrinthine fistula was most commonly located on lateral semicircular canal (15/17, 88.2%). 2. Fusion of vestibule with lateral semicircular canal and formation of common cavity was demonstrated incidentally in 5 patients (0.7% of total number of temporal bone CT), and bilateral in 3 patients. 3. The incidence of inner ear anomaly in congenital ear anomaly was 11.4% (5/44). All cases were bilateral and three patients showed associated middle ear anomaly. 4. The incidence of involvement of bony labyrinth in temporal bone fracture was 10.2% (5/49). Labyrinthine fracture was seen all patients of transverse(3) and mixed fracture(1). In longitudinal fracture, labyrinthine fracture was seen in 2.2% (1/45). 5. Others were traumatic labyrinthitis ossificans(1), intracanalicular acoustic neuroma(3) and facial nerve neuroma(1)

  9. [Imaging and audiology analysis of the congenital inner ear malformations].

    Zhou, Bao; Lin, Shaolian; Lin, Youhui; Fang, Zheming; Ye, Shengnan; Zhang, Rong


    To investigate imaging and audiology features of temporal bone and analyze the classification and prevalence of inner ear abnormalities in children with sensorineural hearing loss. Children who were diagnosed with sensorineural hearing loss were examined by high resolution CT and the inner ear fluid of MRI. And each chart was retrospectively reviewed to determine the imaging and audiology features. There were 125 patients(232 ears) found with inner ear malformation in 590 children with SNHL. About 21.71% of the inner ear malformation occurred in severe and profound hearing loss ears, and 12.85% occurred in r moderate hearing loss ears. The inner ear malformation rate in normal hearing ears were 13.59%. CT and MRI examinations of temporal bone are important diagnostic tools to indentify inner ear malformations. Inner ear malformations are almost bilateral and hearing loss are profoud. Cochleo-vestibular malformations and large vestibular aqueduct are the 2 most frequent deformities. Among the children with SNHL, deformity rate in the severe and profound hearing loss ears is higher than that in moderate hearing loss ear. Inner ear malformations can exist in people with normal hearing.

  10. Inner ear dysfunction in caspase-3 deficient mice

    Woo Minna


    Full Text Available Abstract Background Caspase-3 is one of the most downstream enzymes activated in the apoptotic pathway. In caspase-3 deficient mice, loss of cochlear hair cells and spiral ganglion cells coincide closely with hearing loss. In contrast with the auditory system, details of the vestibular phenotype have not been characterized. Here we report the vestibular phenotype and inner ear anatomy in the caspase-3 deficient (Casp3-/- mouse strain. Results Average ABR thresholds of Casp3-/- mice were significantly elevated (P Casp3+/- mice and Casp3+/+ mice at 3 months of age. In DPOAE testing, distortion product 2F1-F2 was significantly decreased (P Casp3-/- mice, whereas Casp3+/- and Casp3+/+ mice showed normal and comparable values to each other. Casp3-/- mice were hyperactive and exhibited circling behavior when excited. In lateral canal VOR testing, Casp3-/- mice had minimal response to any of the stimuli tested, whereas Casp3+/- mice had an intermediate response compared to Casp3+/+ mice. Inner ear anatomical and histological analysis revealed gross hypomorphism of the vestibular organs, in which the main site was the anterior semicircular canal. Hair cell numbers in the anterior- and lateral crista, and utricle were significantly smaller in Casp3-/- mice whereas the Casp3+/- and Casp3+/+ mice had normal hair cell numbers. Conclusions These results indicate that caspase-3 is essential for correct functioning of the cochlea as well as normal development and function of the vestibule.

  11. Restrictions in cell cycle progression of adult vestibular supporting cells in response to ectopic cyclin D1 expression.

    Heidi Loponen

    Full Text Available Sensory hair cells and supporting cells of the mammalian inner ear are quiescent cells, which do not regenerate. In contrast, non-mammalian supporting cells have the ability to re-enter the cell cycle and produce replacement hair cells. Earlier studies have demonstrated cyclin D1 expression in the developing mouse supporting cells and its downregulation along maturation. In explant cultures of the mouse utricle, we have here focused on the cell cycle control mechanisms and proliferative potential of adult supporting cells. These cells were forced into the cell cycle through adenoviral-mediated cyclin D1 overexpression. Ectopic cyclin D1 triggered robust cell cycle re-entry of supporting cells, accompanied by changes in p27(Kip1 and p21(Cip1 expressions. Main part of cell cycle reactivated supporting cells were DNA damaged and arrested at the G2/M boundary. Only small numbers of mitotic supporting cells and rare cells with signs of two successive replications were found. Ectopic cyclin D1-triggered cell cycle reactivation did not lead to hyperplasia of the sensory epithelium. In addition, a part of ectopic cyclin D1 was sequestered in the cytoplasm, reflecting its ineffective nuclear import. Combined, our data reveal intrinsic barriers that limit proliferative capacity of utricular supporting cells.

  12. Influence of EARLI1-like genes on flowering time and lignin synthesis of Arabidopsis thaliana.

    Shi, Y; Zhang, X; Xu, Z-Y; Li, L; Zhang, C; Schläppi, M; Xu, Z-Q


    EARLI1 encodes a 14.7 kDa protein in the cell wall, is a member of the PRP (proline-rich protein) family and has multiple functions, including resistance to low temperature and fungal infection. RNA gel blot analyses in the present work indicated that expression of EARLI1-like genes, EARLI1, At4G12470 and At4G12490, was down-regulated in Col-FRI-Sf2 RNAi plants derived from transformation with Agrobacterium strain ABI, which contains a construct encoding a double-strand RNA targeting 8CM of EARLI1. Phenotype analyses revealed that Col-FRI-Sf2 RNAi plants of EARLI1 flowered earlier than Col-FRI-Sf2 wild-type plants. The average bolting time of Col-FRI-Sf2 and Col-FRI-Sf2 RNAi plants was 39.7 and 19.4 days, respectively, under a long-day photoperiod. In addition, there were significant differences in main stem length, internode number and rosette leaf number between Col-FRI-Sf2 and Col-FRI-Sf2 RNAi plants. RT-PCR showed that EARLI1-like genes might delay flowering time through the autonomous and long-day photoperiod pathways by maintaining the abundance of FLC transcripts. In Col-FRI-Sf2 RNAi plants, transcription of FLC was repressed, while expression of SOC1 and FT was activated. Microscopy observations showed that EARLI1-like genes were also associated with morphogenesis of leaf cells in Arabidopsis. Using histochemical staining, EARLI1-like genes were found to be involved in regulation of lignin synthesis in inflorescence stems, and Col-FRI-Sf2 and Col-FRI-Sf2 RNAi plants had 9.67% and 8.76% dry weight lignin, respectively. Expression analysis revealed that cinnamoyl-CoA reductase, a key enzyme in lignin synthesis, was influenced by EARLI1-like genes. These data all suggest that EARLI1-like genes could control the flowering process and lignin synthesis in Arabidopsis.

  13. Mammalian Otolin: a multimeric glycoprotein specific to the inner ear that interacts with otoconial matrix protein Otoconin-90 and Cerebellin-1.

    Michael R Deans

    Full Text Available The mammalian otoconial membrane is a dense extracellular matrix containing bio-mineralized otoconia. This structure provides the mechanical stimulus necessary for hair cells of the vestibular maculae to respond to linear accelerations and gravity. In teleosts, Otolin is required for the proper anchoring of otolith crystals to the sensory maculae. Otoconia detachment and subsequent entrapment in the semicircular canals can result in benign paroxysmal positional vertigo (BPPV, a common form of vertigo for which the molecular basis is unknown. Several cDNAs encoding protein components of the mammalian otoconia and otoconial membrane have recently been identified, and mutations in these genes result in abnormal otoconia formation and balance deficits.Here we describe the cloning and characterization of mammalian Otolin, a protein constituent of otoconia and the otoconial membrane. Otolin is a secreted glycoprotein of ∼70 kDa, with a C-terminal globular domain that is homologous to the immune complement C1q, and contains extensive posttranslational modifications including hydroxylated prolines and glycosylated lysines. Like all C1q/TNF family members, Otolin multimerizes into higher order oligomeric complexes. The expression of otolin mRNA is restricted to the inner ear, and immunohistochemical analysis identified Otolin protein in support cells of the vestibular maculae and semi-circular canal cristae. Additionally, Otolin forms protein complexes with Cerebellin-1 and Otoconin-90, two protein constituents of the otoconia, when expressed in vitro. Otolin was also found in subsets of support cells and non-sensory cells of the cochlea, suggesting that Otolin is also a component of the tectorial membrane.Given the importance of Otolin in lower organisms, the molecular cloning and biochemical characterization of the mammalian Otolin protein may lead to a better understanding of otoconial development and vestibular dysfunction.

  14. Anteverted concha: A new ear deformational anomaly

    Fabrizio Schönauer


    Full Text Available Most auricular deformities involve the helix and the antihelix (Stahl's bar, lop and prominent ear; an isolated conchal deformity is uncommon in an otherwise normal ear. When a convexity rather than a concavity of the concha is present, it can be defined as “anteverted concha”. The anteverted concha causes not only aesthetic but also functional problems. It may be so severe as to occlude the external auditory meatus. In a newborn ear amenable to moulding, anteverted concha can be treated non-surgically by splinting. If this time window has passed, then surgical excision of the conchal bulge can give good results in the adult. We present two such cases and their treatment.

  15. [Bone Conduction and Active Middle Ear Implants].

    Volkenstein, S; Thomas, J P; Dazert, S


    The majority of patients with moderate to severe hearing loss can be supplied with conventional hearing aids depending on severity and cause for hearing loss in a satisfying way. However, some patients either do not benefit enough from conventional hearing aids or cannot wear them due to inflammatory reactions and chronic infections of the external auditory canal or due to anatomical reasons. For these patients there are fully- and semi-implantable middle ear and bone conduction implants available. These devices either directly stimulate the skull (bone conduction devices), middle ear structures (active middle ear implants) or the cochlea itself (direct acoustic stimulation). Patients who failed surgical hearing rehabilitation or do not benefit from conventional hearing aids may achieve a significant better speech understanding and tremendous improvement in quality of life by implantable hearing devices with careful attention to the audiological and anatomical indication criteria.

  16. Precise individualized armature for ear reconstruction

    Evenhouse, Raymond J.; Chen, Xiaoming


    The cosmetic result of an ear restored surgically or via prosthetics is dependent on the surgeon''s ability to carve a precise cartilage armature at the time of surgery or the prosthetist''s ability to sculpt in wax an exact duplicate of the patient''s " missing" ear. Introducing CAD/CAM technology into the process benefits the esthetic outcome of these procedures. By utilizing serial section information derived from CAT MRI or moulage techniques a mirrorimage of the patient''s " donor" ear is generated. The resulting earform data is then used for the design of a cartilage armature produced by multi-axis milling or to produce by stereolithography a model which serves as the basis for a prosthesis.

  17. Sensory Perception: Lessons from Synesthesia

    Harvey, Joshua Paul


    Synesthesia, the conscious, idiosyncratic, repeatable, and involuntary sensation of one sensory modality in response to another, is a condition that has puzzled both researchers and philosophers for centuries. Much time has been spent proving the condition’s existence as well as investigating its etiology, but what can be learned from synesthesia remains a poorly discussed topic. Here, synaesthesia is presented as a possible answer rather than a question to the current gaps in our understanding of sensory perception. By first appreciating the similarities between normal sensory perception and synesthesia, one can use what is known about synaesthesia, from behavioral and imaging studies, to inform our understanding of “normal” sensory perception. In particular, in considering synesthesia, one can better understand how and where the different sensory modalities interact in the brain, how different sensory modalities can interact without confusion ― the binding problem ― as well as how sensory perception develops. PMID:23766741

  18. The acoustical significance of age-dependent ear elongation

    Christensen, Flemming


    Elderly people, especially some old men, appear to have very large ears. This paper presents an investigation on the acoustic significance of the age dependent ear elongation. HRTFs and ear lengths were measured for two groups of young and old people. The older groups had larger ears on average......, corresponding to what is reported in the literature. For female ears, virtually no acoustical effect was found. For male ears directional dependent effects in the range up to 5 dB on average was found for certain directions and frequencies. Implications on age dependent hearing loss (presbycusis...

  19. A Combinatorial Approach to Induce Sensory Axon Regeneration into the Dorsal Root Avulsed Spinal Cord

    Hoeber, Jan; Konig, Niclas; Trolle, Carl


    restores sensory functions. In this study, we elucidate mechanisms underlying stem cell-mediated ingrowth of sensory axons after dorsal root avulsion (DRA). We show that human spinal cord neural stem/progenitor cells (hscNSPC), and also, mesoporous silica particles loaded with growth factor mimetics (MesoMIM......), supported sensory axon regeneration. However, when hscNSPC and MesoMIM were combined, sensory axon regeneration failed. Morphological and tracing analysis showed that sensory axons grow through the newly established glial scar along “bridges” formed by migrating stem cells. Coimplantation of MesoMIM...... prevented stem cell migration, “bridges” were not formed, and sensory axons failed to enter the spinal cord. MesoMIM applied alone supported sensory axons ingrowth, but without affecting glial scar formation. In vitro, the presence of MesoMIM significantly impaired migration of hscNSPC without affecting...

  20. The Frog Inner Ear: Picture Perfect?

    Mason, Matthew James; Segenhout, Johannes M.; Cobo-Cuan, Ariadna; Quiñones, Patricia M.; van Dijk, Pim


    This is the accepted manuscript of a paper published in the Journal of the Association for Research in Otolaryngology (2015) DOI: 10.1007/s10162-015-0506-z Many recent accounts of the frog peripheral auditory system have reproduced Wever’s (1973) schematic cross-section of the ear of a leopard frog. We sought to investigate to what extent this diagram is an accurate and representative depiction of the anuran inner ear, using three-dimensional reconstructions made from serial sections of Ra...