scholarly journals Ultrastructural localization of Na,K-ATPase in the gerbil cochlea.

1995 ◽  
Vol 43 (10) ◽  
pp. 981-991 ◽  
Author(s):  
K Nakazawa ◽  
S S Spicer ◽  
B A Schulte
Keyword(s):  
Cell Membrane ◽  
Spiral Ganglion ◽  
Ultrastructural Localization ◽  
Cell Types ◽  
Spiral Ligament ◽  
Type I ◽  
Electron Microscopic ◽  
Enzyme Cytochemistry ◽  
Efferent Nerve ◽  
Ganglion Neurons

The transport enzyme Na,K-ATPase has been localized to several different cell types within the inner ear by enzyme cytochemistry, immunohistochemistry, and in situ hybridization. Although these histochemical procedures have provided a fairly consistent pattern of the enzyme's distribution, the precise location of Na,K-ATPase in the cell membrane of some polarized and non-polarized cell types remains uncertain. We addressed this problem in the gerbil cochlea using electron microscopic immunogold cytochemistry. The results confirmed prior ultrastructural localization of Na,K-ATPase along the basolateral plasma membrane of strial marginal and outer sulcus epithelial cells but differed from a previous report in failing to detect the enzyme at the surface of strial intermediate cells. The findings also concurred with and extended previous work in showing immunogold labeling along the entire cell membrane of non-polarized Type II fibrocytes in the inferior portion of the spiral ligament and of subpopulations of fibrocytes in the suprastrial and supralimbal regions. Our observations agreed further with light microscopic immunostaining in displaying uniform gold labeling for Na,K-ATPase in the neurilemma of Type I spiral ganglion neurons, even though these cells are completely ensheathed by myelin. Surprisingly, the enzyme was detectable in the neurilemma of afferent but not that of efferent nerve processes beneath hair cells.

scholarly journals Type 1 Diabetes Induces Hearing Loss: Functional and Histological Findings in An Akita Mouse Model

Biomedicines ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 343
Author(s):  
Yun Yeong Lee ◽  
Yeon Ju Kim ◽  
Eun Sol Gil ◽  
Hantai Kim ◽  
Jeong Hun Jang ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Hearing Loss ◽  
Spiral Ganglion ◽  
Spiral Ganglion Neurons ◽  
Blood Capillary ◽  
Spiral Ligament ◽  
Type I ◽  
Ganglion Neurons ◽  
Akita Mice

The relationship between type 1 diabetes and hearing loss is not well known, although based on many pathological studies, type 2 diabetes induced hearing loss is associated with microcirculation problems in the inner ear. The purpose of this study was to investigate the correlation between type 1 diabetes and hearing loss through hearing function and immunohistochemical analyses using type 1 diabetic Akita or wild-type (WT) mice. The Akita mice had a significant increase in hearing thresholds, blood glucose, and insulin tolerance compared to WT mice. Histological analysis showed that the loss of cells and damage to mitochondria in the spiral ganglion neurons of Akita mice were significantly increased compared to WT. Also, the stria vascularis showed decreased thickness, loss of intermediate cells, and disturbance in blood capillary shape in the Akita mice. Moreover, a reduction in type I, II, and IV fibrocytes and Na+/K+-ATPase α1 expression in spiral ligament was also observed. Cleaved caspase-3 expression was highly expressed in spiral ganglion neurons. In conclusion, hearing loss in type 1 diabetes is caused not only by ion imbalance and blood flow disorders of cochlear endolymph, but through the degenerative nervous system via apoptosis-mediated cell death.

scholarly journals Pou4f1 Defines a Subgroup of Type I Spiral Ganglion Neurons and Is Necessary for Normal Inner Hair Cell Presynaptic Ca2+ Signaling

2019 ◽  
Vol 39 (27) ◽  
pp. 5284-5298 ◽  
Author(s):  
Hanna E. Sherrill ◽  
Philippe Jean ◽  
Elizabeth C. Driver ◽  
Tessa R. Sanders ◽  
Tracy S. Fitzgerald ◽  
...  
Keyword(s):  
Hair Cell ◽  
Spiral Ganglion ◽  
Spiral Ganglion Neurons ◽  
Type I ◽  
Inner Hair Cell ◽  
Ganglion Neurons

Acid Phosphatase Activity in Spiral Ganglion Neurons of C57BL/6 Mice

1998 ◽  
Vol 4 (S2) ◽  
pp. 1104-1105
Author(s):  
Glenn M. Cohen
Keyword(s):  
Acid Phosphatase ◽  
Spiral Ganglion ◽  
Distribution Patterns ◽  
Electron Microscopic ◽  
Age Related ◽  
Sensory Hair Cells ◽  
Dense Deposits ◽  
Underlying Mechanisms ◽  
Ganglion Neurons ◽  
Marker Molecule

C57BL/6 mice, along with several other mouse genotypes, have served as models for human presbycusis (age-related hearing losses). C57BL/6 mice and their genetic substrain C57/M6 show progressively severe hearing losses, starting as early as 30 days postnatally. The hearing losses result from sweeping degeneration of sensory (hair) cells and neurons that begins in the basal end of the cochlea and advances apically. Although the underlying mechanisms orchestrating sensory and neural degeneration are not known, it is possible to correlate degenerative events with the cytoplasmic levels and distribution patterns of a marker molecule, such as acid phosphatase (AP). AP, a representative lysosomal enzyme, plays a role in both normal cellular metabolism and degenerative changes (trauma and senescence). AP activity is visualized histochemically at the light and electron microscopic levels by the presence of dense deposits within lysosomes.

scholarly journals The neuronal endoplasmic reticulum: its cytochemistry and contribution to the endomembrane system. I. Cell bodies and dendrites.

1983 ◽  
Vol 31 (9) ◽  
pp. 1077-1088 ◽  
Author(s):  
R D Broadwell ◽  
A M Cataldo
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Cell Types ◽  
Endomembrane System ◽  
Cell Organelles ◽  
Electron Microscopic ◽  
Enzyme Cytochemistry ◽  
G6pase Activity ◽  
Numerous Cell ◽  
Intracellular Compartments

The endoplasmic reticulum (ER) and its contribution to the endomembrane system (i.e., membranes of cell organelles) in the neuron have been investigated in brains of mice by applying electron microscopic enzyme cytochemistry for demonstration of glucose-6-phosphatase (G6Pase) activity. The phosphohydrolytic activity of G6Pase is a well-known cytochemical marker for the ER in numerous cell types. Of the different substrates employed, glucose-6-phosphate and mannose-6-phosphate were the only two with which G6Pase reaction product was seen in the neuronal ER and organelles related morphologically to the ER. G6Pase activity in cell bodies and dendrites was localized consistently within the lumen of the nuclear envelope, rough and smooth ER, lamellar bodies, hypolemmal and subsurface cisternae, and frequently in the cis saccules of the Golgi apparatus. The G6Pase reactive ER appeared as a network of saccules and tubules pervading the cell body and its dendrites. Possible membrane continuities were identified between the ER and the other reactive structures, including the cis half of the Golgi apparatus. Neither G6Pase activity nor reactive ER was associated with the trans Golgi saccules or GERL. G6Pase activity thus serves as a reliable marker for the perikaryal and dendritic ER and related structures. These observations support the theory that the ER is an integral component of the neuronal endomembrane system associated with the transfer of membrane or membrane molecules among intracellular compartments, the packaging and transport of exportable protein, and energy metabolism. G6Pase activity in the ER of axons and terminals is considered in detail in part two of this study.

scholarly journals Gpr125 Marks Distinct Cochlear Cell Types and Is Dispensable for Cochlear Development and Hearing

2021 ◽  
Vol 9 ◽  
Author(s):  
Haiying Sun ◽  
Tian Wang ◽  
Patrick J. Atkinson ◽  
Sara E. Billings ◽  
Wuxing Dong ◽  
...  
Keyword(s):  
Spiral Ganglion ◽  
Cell Types ◽  
Supporting Cell ◽  
Outer Hair Cells ◽  
Sensory Cells ◽  
Convergent Extension ◽  
Multiple Organs ◽  
Auditory Physiology ◽  
Cochlear Development ◽  
Ganglion Neurons

The G protein-coupled receptor (GPR) family critically regulates development and homeostasis of multiple organs. As a member of the GPR adhesion family, Gpr125 (Adgra3) modulates Wnt/PCP signaling and convergent extension in developing zebrafish, but whether it is essential for cochlear development in mammals is unknown. Here, we examined the Gpr125lacZ/+ knock-in mice and show that Gpr125 is dynamically expressed in the developing and mature cochleae. From embryonic day (E) 15.5 to postnatal day (P) 30, Gpr125-β-Gal is consistently expressed in the lesser epithelial ridge and its presumed progenies, the supporting cell subtypes Claudius cells and Hensen’s cells. In contrast, Gpr125-β-Gal is expressed transiently in outer hair cells, epithelial cells in the lateral cochlear wall, interdental cells, and spiral ganglion neurons in the late embryonic and early postnatal cochlea. In situ hybridization for Gpr125 mRNA confirmed Gpr125 expression and validated loss of expression in Gpr125lacZ/lacZ cochleae. Lastly, Gpr125lacZ/+ and Gpr125lacZ/lacZ cochleae displayed no detectable loss or disorganization of either sensory or non-sensory cells in the embryonic and postnatal ages and exhibited normal auditory physiology. Together, our study reveals that Gpr125 is dynamically expressed in multiple cell types in the developing and mature cochlea and is dispensable for cochlear development and hearing.

scholarly journals Postnatal Development of Microglia-Like Cells in Mouse Cochlea

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Penghui Chen ◽  
Yongchuan Chai ◽  
Haijin Liu ◽  
Gen Li ◽  
Longhao Wang ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Morphological Changes ◽  
Spiral Ganglion ◽  
Organ Of Corti ◽  
Specific Marker ◽  
Spiral Ligament ◽  
Type I ◽  
Cochlear Inflammation ◽  
Cochlear Development ◽  
The Central Nervous System

Microglial cells are involved in surveillance and cleaning of the central nervous system. Recently, microglial-like cells (MLC) have been found in an adult cochlea and investigated for their role in cochlear inflammation. The presence and potential roles of MLCs during the development of the cochlea, however, remain unclear. In this study, immunostaining was performed using the MLC-specific marker IBA1 to characterize the presence, distribution, and morphology of MLCs in the developing cochlea. From P0 to P14, MLCs were present in a variety of cochlear regions including the modiolus, spiral lamina, spiral ganglion, spiral ligament, and the organ of Corti. Interestingly, the overall number of MLCs in a mouse cochlea steadily increased since P0, peaks at P5, then gradually decreased from P5 to P14. In the spiral ligament, the distribution of the MLCs trends to shift from the type I/II fibrocyte-rich regions to the type III/IV fibrocyte-rich regions during the course of cochlear development, accompanied by the morphological changes of MLCs from the amoeboid, activated form to the ramified, quiescent form. Our results suggested that MLCs experience drastic morphological and distributional changes during postnatal cochlear development, which may play a role in the maturing and remodeling of the cochlea.

Dynamic firing properties of type I spiral ganglion neurons

2015 ◽  
Vol 361 (1) ◽  
pp. 115-127 ◽  
Author(s):  
Robin L. Davis ◽  
Robert A. Crozier
Keyword(s):  
Spiral Ganglion ◽  
Spiral Ganglion Neurons ◽  
Type I ◽  
Firing Properties ◽  
Ganglion Neurons

Analog Transmission of Action Potential Fine Structure in Spiral Ganglion Axons

2021 ◽  
Author(s):  
Wenke Liu ◽  
Qing Liu ◽  
Robert A. Crozier ◽  
Robin L. Davis
Keyword(s):  
Fine Structure ◽  
Action Potential ◽  
Action Potentials ◽  
Spiral Ganglion ◽  
Type I ◽  
Sensory Afferents ◽  
Conduction Pathway ◽  
Highly Correlated ◽  
Voltage Gated Ion Channels ◽  
Ganglion Neurons

Action potential waveforms generated at the axon initial segment (AIS) are specialized between and within neuronal classes. But is the fine structure of each electrical event retained when transmitted along myelinated axons or is it rapidly and uniformly transmitted to be modified again at the axon terminal? To address this issue action potential axonal transmission was evaluated in a class of primary sensory afferents that possess numerous types of voltage-gated ion channels underlying a complex repertoire of endogenous firing patterns. In addition to their signature intrinsic electrophysiological heterogeneity, spiral ganglion neurons are uniquely designed. The bipolar, myelinated somata of type I neurons are located within the conduction pathway, requiring that action potentials generated at the first heminode must be conducted through their electrically excitable membrane. We utilized this unusual axonal-like morphology to serve as a window into action potential transmission to compare locally-evoked action potential profiles to those generated peripherally at their glutamatergic synaptic connections with hair cell receptors. These comparisons showed that the distinctively-shaped somatic action potentials were highly correlated with the nodally-generated, invading ones for each neuron. This result indicates that the fine structure of the action potential waveform is maintained axonally, thus supporting the concept that analog signaling is incorporated into each digitally-transmitted action potential in the specialized primary auditory afferents.

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