scholarly journals Ribbon development in chicken hair cells: Developmental maturation of presynaptic ribbon numbers in chicken basilar‐papilla hair cells and its perturbation by long‐term overexpression of Wnt9a

2021 ◽  
Author(s):  
M. Queralt Caus Capdevila ◽  
Ulrike J. Sienknecht ◽  
Christine Köppl
Keyword(s):  
Hair Cells ◽  
Basilar Papilla ◽  
Developmental Maturation

scholarly journals Electrical tuning and transduction in short hair cells of the chicken auditory papilla

2013 ◽  
Vol 109 (8) ◽  
pp. 2007-2020 ◽  
Author(s):  
Xiaodong Tan ◽  
Maryline Beurg ◽  
Carole Hackney ◽  
Shanthini Mahendrasingam ◽  
Robert Fettiplace
Keyword(s):  
Hair Cells ◽  
Calcium Binding ◽  
Outer Hair Cells ◽  
Basilar Papilla ◽  
Resting Potential ◽  
Auditory Nerve Fiber ◽  
Buffer Concentration ◽  
Short Hair ◽  
Open Probability ◽  
Calbindin D

The avian auditory papilla contains two classes of sensory receptor, tall hair cells (THCs) and short hair cells (SHCs), the latter analogous to mammalian outer hair cells with large efferent but sparse afferent innervation. Little is known about the tuning, transduction, or electrical properties of SHCs. To address this problem, we made patch-clamp recordings from hair cells in an isolated chicken basilar papilla preparation at 33°C. We found that SHCs are electrically tuned by a Ca2+-activated K+ current, their resonant frequency varying along the papilla in tandem with that of the THCs, which also exhibit electrical tuning. The tonotopic map for THCs was similar to maps previously described from auditory nerve fiber measurements. SHCs also possess an A-type K+ current, but electrical tuning was observed only at resting potentials positive to −45 mV, where the A current is inactivated. We predict that the resting potential in vivo is approximately −40 mV, depolarized by a standing inward current through mechanotransducer (MT) channels having a resting open probability of ∼0.26. The resting open probability stems from a low endolymphatic Ca2+ concentration (0.24 mM) and a high intracellular mobile Ca2+ buffer concentration, estimated from perforated-patch recordings as equivalent to 0.5 mM BAPTA. The high buffer concentration was confirmed by quantifying parvalbumin-3 and calbindin D-28K with calibrated postembedding immunogold labeling, demonstrating >1 mM calcium-binding sites. Both proteins displayed an apex-to-base gradient matching that in the MT current amplitude, which increased exponentially along the papilla. Stereociliary bundles also labeled heavily with antibodies against the Ca2+ pump isoform PMCA2a.

Delta1 expression during avian hair cell regeneration

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 961-973 ◽  
Author(s):  
J.S. Stone ◽  
E.W. Rubel
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Hair Cells ◽  
Cell Injury ◽  
Basilar Papilla ◽  
Cell Regeneration ◽  
Mrna Levels ◽  
Hair Cell Regeneration ◽  
Drug Induced ◽  
In Cells

Postembryonic production of hair cells, the highly specialized receptors for hearing, balance and motion detection, occurs in a precisely controlled manner in select species, including avians. Notch1, Delta1 and Serrate1 mediate cell specification in several tissues and species. We examined expression of the chicken homologs of these genes in the normal and drug-damaged chick inner ear to determine if signaling through this pathway changes during hair cell regeneration. In untreated post-hatch chicks, Delta1 mRNA is abundant in a subpopulation of cells in the utricle, which undergoes continual postembryonic hair cell production, but it is absent from all cells in the basilar papilla, which is mitotically quiescent. By 3 days after drug-induced hair cell injury, Delta1 expression is highly upregulated in areas of cell proliferation in both the utricle and basilar papilla. Delta1 mRNA levels are elevated in progenitor cells during DNA synthesis and/or gap 2 phases of the cell cycle and expression is maintained in both daughter cells immediately after mitosis. Delta1 expression remains upregulated in cells that differentiate into hair cells and is downregulated in cells that do not acquire the hair cell fate. Delta1 mRNA levels return to normal by 10 days after hair cell injury. Serrate1 is expressed in both hair cells and support cells in the utricle and basilar papilla, and its expression does not change during the course of drug-induced hair cell regeneration. In contrast, Notch1 expression, which is limited to support cells in the quiescent epithelium, is increased in post-M-phase cell pairs during hair cell regeneration. This study provides initial evidence that Delta-Notch signaling may be involved in maintaining the correct cell types and patterns during postembryonic replacement of sensory epithelial cells in the chick inner ear.

Morphological and morphometric characteristics of vestibular hair cells and support cells in long term cultures of rat utricle explants

2012 ◽  
Vol 283 (1-2) ◽  
pp. 107-116 ◽  
Author(s):  
Mimmi Werner ◽  
Thomas R. Van De Water ◽  
Therese Andersson ◽  
Göran Arnoldsson ◽  
Diana Berggren
Keyword(s):  
Hair Cells ◽  
Morphometric Characteristics ◽  
Vestibular Hair Cells

Potassium currents in auditory hair cells of the frog basilar papilla

1999 ◽  
Vol 132 (1-2) ◽  
pp. 117-130 ◽  
Author(s):  
Michael S Smotherman ◽  
Peter M Narins
Keyword(s):  
Hair Cells ◽  
Potassium Currents ◽  
Basilar Papilla ◽  
Auditory Hair Cells

scholarly journals SK Current, Expressed During the Development and Regeneration of Chick Hair Cells, Contributes to the Patterning of Spontaneous Action Potentials

2022 ◽  
Vol 15 ◽  
Author(s):  
Snezana Levic
Keyword(s):  
Electrical Activity ◽  
Hair Cells ◽  
Action Potentials ◽  
Functional Expression ◽  
Basilar Papilla ◽  
Spontaneous Electrical Activity ◽  
Intracellular Ca ◽  
Spontaneous Action ◽  
Spontaneous Action Potentials

Chick hair cells display calcium (Ca2+)-sensitive spontaneous action potentials during development and regeneration. The role of this activity is unclear but thought to be involved in establishing proper synaptic connections and tonotopic maps, both of which are instrumental to normal hearing. Using an electrophysiological approach, this work investigated the functional expression of Ca2+-sensitive potassium [IK(Ca)] currents and their role in spontaneous electrical activity in the developing and regenerating hair cells (HCs) in the chick basilar papilla. The main IK(Ca) in developing and regenerating chick HCs is an SK current, based on its sensitivity to apamin. Analysis of the functional expression of SK current showed that most dramatic changes occurred between E8 and E16. Specifically, there is a developmental downregulation of the SK current after E16. The SK current gating was very sensitive to the availability of intracellular Ca2+ but showed very little sensitivity to T-type voltage-gated Ca2+ channels, which are one of the hallmarks of developing and regenerating hair cells. Additionally, apamin reduced the frequency of spontaneous electrical activity in HCs, suggesting that SK current participates in patterning the spontaneous electrical activity of HCs.

Hearing and hair cells

2019 ◽  
pp. 99-131
Author(s):  
Gordon L. Fain
Keyword(s):  
Hair Cells ◽  
Endocochlear Potential ◽  
Outer Hair Cells ◽  
Sensory Transduction ◽  
Basilar Papilla ◽  
Sensory Receptors ◽  
Anatomy And Physiology ◽  
Electrical Resonance ◽  
Present Understanding

“Hearing and hair cells” is the sixth chapter of the book Sensory Transduction and begins with hearing in insects, describing the anatomy and physiology of tympanal organs and Johnston’s organ. It reviews the literature on vertebrate hair cells, which are the sensory receptors of the inner ear. It begins with the anatomy of hair cells and then describes tip links, hair cell transduction proteins, and our present understanding of the nature and identity of the mechanoreceptive channels, including the role of channel gating in bundle stiffness and adaptation of hair cells. A review is given of the anatomy and physiology of the organs of the lateral line, the vestibular system, and the cochlea, together with a description of endolymph and the endocochlear potential, outer hair cells and tuning in mammals, and the role of electrical resonance in tuning in the turtle basilar papilla.

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