Effects of underwater sound on hair cells of the inner ear and lateral line of the oscar (Astronotus ocellatus).

1996 ◽  
Vol 99 (4) ◽  
pp. 2576-2603
Author(s):  
Mardi C. Hastings ◽  
Arthur N. Popper ◽  
James J. Finneran ◽  
Pamela J. Lanford
Keyword(s):  
Inner Ear ◽  
Lateral Line ◽  
Hair Cells ◽  
Underwater Sound ◽  
Astronotus Ocellatus

scholarly journals Macrophages Respond Rapidly to Ototoxic Injury of Lateral Line Hair Cells but Are Not Required for Hair Cell Regeneration

2021 ◽  
Vol 14 ◽  
Author(s):  
Mark E. Warchol ◽  
Angela Schrader ◽  
Lavinia Sheets
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Lateral Line ◽  
Hair Cells ◽  
Control Fish ◽  
Cell Regeneration ◽  
Cellular Interactions ◽  
Hair Cell Regeneration ◽  
Genetic Ablation ◽  
Larval Zebrafish

The sensory organs of the inner ear contain resident populations of macrophages, which are recruited to sites of cellular injury. Such macrophages are known to phagocytose the debris of dying cells but the full role of macrophages in otic pathology is not understood. Lateral line neuromasts of zebrafish contain hair cells that are nearly identical to those in the inner ear, and the optical clarity of larval zebrafish permits direct imaging of cellular interactions. In this study, we used larval zebrafish to characterize the response of macrophages to ototoxic injury of lateral line hair cells. Macrophages migrated into neuromasts within 20 min of exposure to the ototoxic antibiotic neomycin. The number of macrophages in the near vicinity of injured neuromasts was similar to that observed near uninjured neuromasts, suggesting that this early inflammatory response was mediated by “local” macrophages. Upon entering injured neuromasts, macrophages actively phagocytosed hair cell debris. The injury-evoked migration of macrophages was significantly reduced by inhibition of Src-family kinases. Using chemical-genetic ablation of macrophages before the ototoxic injury, we also examined whether macrophages were essential for the initiation of hair cell regeneration. Results revealed only minor differences in hair cell recovery in macrophage-depleted vs. control fish, suggesting that macrophages are not essential for the regeneration of lateral line hair cells.

scholarly journals Vestibular and Auditory Hair Cell Regeneration Following Targeted Ablation of Hair Cells With Diphtheria Toxin in Zebrafish

2021 ◽  
Vol 15 ◽  
Author(s):  
Erin Jimenez ◽  
Claire C. Slevin ◽  
Luis Colón-Cruz ◽  
Shawn M. Burgess
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Lateral Line ◽  
Hair Cells ◽  
Diphtheria Toxin ◽  
Adult Zebrafish ◽  
Hair Cell Regeneration ◽  
Cell Ablation ◽  
Aquatic Vertebrates

Millions of Americans experience hearing or balance disorders due to loss of hair cells in the inner ear. The hair cells are mechanosensory receptors used in the auditory and vestibular organs of all vertebrates as well as the lateral line systems of aquatic vertebrates. In zebrafish and other non-mammalian vertebrates, hair cells turnover during homeostasis and regenerate completely after being destroyed or damaged by acoustic or chemical exposure. However, in mammals, destroying or damaging hair cells results in permanent impairments to hearing or balance. We sought an improved method for studying hair cell damage and regeneration in adult aquatic vertebrates by generating a transgenic zebrafish with the capacity for targeted and inducible hair cell ablation in vivo. This model expresses the human diphtheria toxin receptor (hDTR) gene under the control of the myo6b promoter, resulting in hDTR expressed only in hair cells. Cell ablation is achieved by an intraperitoneal injection of diphtheria toxin (DT) in adult zebrafish or DT dissolved in the water for larvae. In the lateral line of 5 days post fertilization (dpf) zebrafish, ablation of hair cells by DT treatment occurred within 2 days in a dose-dependent manner. Similarly, in adult utricles and saccules, a single intraperitoneal injection of 0.05 ng DT caused complete loss of hair cells in the utricle and saccule by 5 days post-injection. Full hair cell regeneration was observed for the lateral line and the inner ear tissues. This study introduces a new method for efficient conditional hair cell ablation in adult zebrafish inner ear sensory epithelia (utricles and saccules) and demonstrates that zebrafish hair cells will regenerate in vivo after this treatment.

scholarly journals Macrophages respond rapidly to ototoxic injury of lateral line hair cells but are not required for hair cell regeneration

2020 ◽  
Author(s):  
Mark E. Warchol ◽  
Angela Schrader ◽  
Lavinia Sheets
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Lateral Line ◽  
Hair Cells ◽  
Control Fish ◽  
Cell Regeneration ◽  
Cellular Interactions ◽  
Hair Cell Regeneration ◽  
Genetic Ablation ◽  
Larval Zebrafish

AbstractThe sensory organs of the inner ear contain resident populations of macrophages, which are recruited to sites of cellular injury. Such macrophages are known to phagocytose the debris of dying cells but the full role of macrophages in otic pathology is not understood. Lateral line neuromasts of zebrafish contain hair cells similar to those in the inner ear, and the optical clarity of larval zebrafish permits direct imaging of cellular interactions. In this study, we used larval zebrafish to characterize the response of macrophages to ototoxic injury of lateral line hair cells. Macrophages migrated into neuromasts within 20 min of exposure to the ototoxic antibiotic neomycin. The number of macrophages in close proximity of injured neuromasts was similar to that observed near uninjured neuromasts, suggesting that this early inflammatory response was mediated by ‘local’ macrophages. Upon entering injured neuromasts, macrophages actively phagocytosed hair cell debris. Such phagocytosis was significantly reduced by inhibiting Src-family kinases. Using chemical-genetic ablation of macrophages prior to ototoxic injury, we also examined whether macrophages were essential for the initiation of hair cell regeneration after neomycin exposure. Results revealed only minor differences in hair cell recovery in macrophage-depleted vs. control fish, suggesting that macrophages are not essential for the regeneration of lateral line hair cells.

scholarly journals The lhfpl5 ohnologs lhfpl5a and lhfpl5b are required for mechanotransduction in distinct populations of sensory hair cells in zebrafish

2019 ◽  
Author(s):  
Timothy Erickson ◽  
Itallia V. Pacentine ◽  
Alexandra Venuto ◽  
Rachel Clemens ◽  
Teresa Nicolson
Keyword(s):  
Inner Ear ◽  
Lateral Line ◽  
Hair Cells ◽  
Vestibular Function ◽  
Fusion Partner ◽  
Primary Role ◽  
Mechanical Stimuli ◽  
Vestibular Hair Cells ◽  
Lateral Line Organ ◽  
Line Organ

1AbstractHair cells sense and transmit auditory, vestibular, and hydrodynamic information by converting mechanical stimuli into electrical signals. This process of mechano-electrical transduction (MET) requires a mechanically-gated channel localized in the apical stereocilia of hair cells. In mice, lipoma HMGIC fusion partner-like 5 (LHFPL5) acts as an auxiliary subunit of the MET channel whose primary role is to correctly localize PCDH15 and TMC1 to the mechanotransduction complex. Zebrafish have two lhfpl5 genes (lhfpl5a and lhfpl5b), but their individual contributions to MET channel assembly and function have not been analyzed.Here we show that the zebrafish lhfpl5 genes are expressed in discrete populations of hair cells: lhfpl5a expression is restricted to auditory and vestibular hair cells in the inner ear, while lhfpl5b expression is specific to hair cells of the lateral line organ. Consequently, lhfpl5a mutants exhibit defects in auditory and vestibular function, while disruption of lhfpl5b affects hair cells only in the lateral line neuromasts. In contrast to previous reports in mice, localization of Tmc1 does not depend upon Lhfpl5 function in either the inner ear or lateral line organ. In both lhfpl5a and lhfpl5b mutants, GFP-tagged Tmc1 and Tmc2b proteins still localize to the stereocilia of hair cells. Using a stably integrated GFP-Lhfpl5a transgene, we show that the tip link cadherins Pcdh15a and Cdh23, along with the Myo7aa motor protein, are required for correct Lhfpl5a localization at the tips of stereocilia. Our work corroborates the evolutionarily conserved co-dependence between Lhfpl5 and Pcdh15, but also reveals novel requirements for Cdh23 and Myo7aa to correctly localize Lhfpl5a. In addition, our data suggest that targeting of Tmc1 and Tmc2b proteins to stereocilia in zebrafish hair cells occurs independently of Lhfpl5 proteins.

Inner Ear and Lateral Line Hair Cells

1988 ◽  
pp. 220-227
Author(s):  
Tsuneo Fujita ◽  
Tomio Kanno ◽  
Shigeru Kobayashi
Keyword(s):  
Inner Ear ◽  
Lateral Line ◽  
Hair Cells

scholarly journals Vestibular and auditory hair cell regeneration following targeted ablation of hair cells with diphtheria toxin in zebrafish

2021 ◽  
Author(s):  
Erin Jimenez ◽  
Claire C Slevin ◽  
Luis Colon Cruz ◽  
Shawn M Burgess
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Lateral Line ◽  
Hair Cells ◽  
Diphtheria Toxin ◽  
Adult Zebrafish ◽  
Hair Cell Regeneration ◽  
Cell Ablation ◽  
Aquatic Vertebrates

Millions of Americans experience hearing or balance disorders due to loss of hair cells in the inner ear. The hair cells are mechanosensory receptors used in the auditory and vestibular organs of all vertebrates as well as the lateral line systems of aquatic vertebrates. In zebrafish and other non-mammalian vertebrates, hair cells turn over during homeostasis and regenerate completely after being destroyed or damaged by acoustic or chemical exposure. However in mammals, destroying or damaging hair cells results in permanent impairments to hearing or balance. We sought an improved method for studying hair cell damage and regeneration in adult aquatic vertebrates by generating a transgenic zebrafish with the capacity for targeted and inducible hair cell ablation in vivo. This model expresses the human diphtheria toxin receptor (hDTR) gene under the control of the myo6b promoter, resulting in hDTR expressed only in hair cells. Cell ablation is achieved by an intraperitoneal injection of diphtheria toxin (DT) in adult zebrafish or DT dissolved in the water for larvae. In the lateral line of 5 dpf zebrafish, ablation of hair cells by DT treatment occurred within 2 days in a dose-dependent manner. Similarly, in adult utricles and saccules, a single intraperitoneal injection of 0.05 ng DT caused complete loss of hair cells in the utricle and saccule by 5 days post-injection. Full hair cell regeneration was observed for the lateral line and the inner ear tissues. This study introduces a new method for efficient conditional hair cell ablation in adult zebrafish inner ear sensory epithelia (utricles and saccules) and demonstrates that zebrafish hair cells will regenerate in vivo after this treatment.

scholarly journals A Xenopus neuromast bioassay for chemical ototoxicity

2022 ◽  
Author(s):  
V. Bleu Knight ◽  
Amanda R. Luna ◽  
Elba Serrano
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Lateral Line ◽  
Hair Cells ◽  
Experimental Manipulation ◽  
The Body ◽  
Therapeutic Drug ◽  
Sem Images ◽  
Irreversible Damage ◽  
Mechanosensory Hair Cells

Background: Ototoxic chemicals can impair the senses of hearing and balance in mammals through irreversible damage to the mechanosensory bundles of inner ear hair cells. Fish and amphibians are useful models for investigating ototoxicity because their inner ear hair cells, like those of mammals, are susceptible to damage by ototoxins. Moreover, amphibian mechanosensation is augmented by a lateral line organ on the body surface that comprises external mechanosensory hair cells. The lateral line hair cells are arranged in clusters (neuromasts) and are structurally and functionally similar to inner ear hair cells, but are more accessible for experimental manipulation. Herein, we implemented neuromasts of the amphibian (Xenopus) lateral line as an organ system for evaluating the effects of ototoxic chemicals, such as antibiotics, on mechanosensory hair cell bundles. Methods: We examined the ultrastructure of larval Xenopus laevis neuromasts with scanning electron microscopy (SEM) after larvae were continuously exposed to ototoxic aminoglycoside antibiotics at sub-lethal concentrations (gentamicin; streptomycin; neomycin) for 72 hours. Results: SEM images demonstrated that 72 hours of exposure to antibiotic concentrations greater than 25 μM reduced the hair cell bundle number in lateral line neuromasts. Conclusion: Therapeutic drug studies will benefit from the incorporation of bioassay strategies that evaluate ototoxicity across multiple species including genera of amphibian origin such as Xenopus. Our outcomes support the use of the Xenopus lateral line for identification of potential ototoxic chemicals and suggest that Xenopus neuromast hair cell bundles can withstand antibiotic exposure. The Xenopus bioassay presented here can be incorporated into drug discovery methodology as a high-resolution phenotypic screen for ototoxic effects.

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