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ribbon synapses

Hidden hearing loss is associated with loss of ribbon synapses of cochlea inner hair cells

CATEGORY:6
Research

SCREENSHOT:
Hidden hearing loss is associated with loss of ribbon synapses of cochlea inner hair cells

TITLE:
Hidden hearing loss is associated with loss of ribbon synapses of cochlea inner hair cells

CONTENT:
Biosci Rep. 2021 Mar 18:BSR20201637. doi: 10.1042/BSR20201637. Online ahead of print.

ABSTRACT

This study aimed to observe the changes in the cochlea ribbon synapses after repeated exposure to moderate-to-high intensity noise. Guinea pigs received 95 dB SPL white noise exposure 4 hours a day for consecutive 7 days (we regarded it a medium-term and moderate-intensity noise, or MTMI noise). Animals were divided into 4 groups: Control, 1DPN (1-day post noise), 1WPN (1-week post noise), and 1MPN (1-month post noise). Auditory function analysis by ABR and CAP recordings, as well as ribbon synapse morphological analyses by immunohistochemistry (Ctbp2 and PSD95 staining) were performed one day, one week, and one month after noise exposure. After MTMI noise exposure, the amplitudes of auditory brainstem response (ABR) I and III waves were suppressed. The compound action potential (CAP) threshold was elevated, and CAP amplitude was reduced in the 1DPN group. No apparent changes in hair cell shape, arrangement or number were observed, but the number of ribbon synapse was reduced. The 1WPN and 1MPN groups showed that part of ABR and CAP changes recovered, as well as the synapse number. The defects in cochlea auditory function and synapse changes were observed mainly in the high-frequency region. Together, repeated exposure in MTMI noise can cause hidden hearing loss, which is partially reversible after leaving the noise environment; and MTMI noise induced hidden hearing loss is associated with inner hair cell ribbon synapses.

PMID:33734328 | DOI:10.1042/BSR20201637

SOURCE:
Bioscience reports

PUBLISHER:

PMID:
pubmed:33734328

ID:
0b58ea4968e09ff10f4e1238c494f316pubmed:33734328

DOI:
10.1042/BSR20201637

DATE – PUBLISHED:
Thu, 18 Mar 2021 06:00:00 -0400

DATE – DOI:
2021-03-18T15:54:01Z

DATE – ADDED:
03/18/21 07:41PM

LINK – PUBMED:
https://pubmed.ncbi.nlm.nih.gov/33734328/

LINK – DOI:
https://doi.org/10.1042/BSR20201637

LINK – PUBLISHER:
https://portlandpress.com/bioscirep/article/doi/10.1042/BSR20201637/228102/Hidden-hearing-loss-is-associated-with-loss-of?utm_source=hearinglosstreatmentreport.com

IMAGE:

REFERENCE:
Hearing Loss Treatment Report, Urgent Research, 2021-03-18T23:41:43+00:00, https://www.hearinglosstreatmentreport.com.

Protection of Cochlear Ribbon Synapses and Prevention of Hidden Hearing Loss

CATEGORY:
Research

TITLE:
Protection of Cochlear Ribbon Synapses and Prevention of Hidden Hearing Loss

DESCRIPTION:
In the auditory system, ribbon synapses are vesicle-associated structures located between inner hair cells (IHCs) and spiral ganglion neurons that are implicated in the modulation of trafficking and fusion of synaptic vesicles at the presynaptic terminals. Synapse loss may result in hearing loss and difficulties with understanding speech in a noisy environment. This phenomenon happens without permanent hearing loss; that is, the cochlear synaptopathy is “hidden.” Recent studies have reported…

DATE – PUBLISHED:
Mon, 02 Nov 2020 22:35:10 +0000

LINK – PUBLISHER:
https://www.hindawi.com/journals/np/2020/8815990/

P2rx3 regulates spiral ganglion neuron (SGN) branch refinement, promotes auditory neuron maturation, and could play a role in regenerating lost auditory connections in hearing loss

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7418533/

https://www.eneuro.org/content/eneuro/7/4/ENEURO.0179-20.2020.full.pdf

The Purinergic Receptor P2rx3 is Required for Spiral Ganglion Neuron Branch Refinement during Development
Zhirong Wang, Johnny S. Jung, Talya C. Inbar, Katherine M. Rangoussis, Christian Faaborg-Andersen,
and Thomas M. Coate
https://doi.org/10.1523/ENEURO.0179-20.2020
Department of Biology, Georgetown University, Washington, DC 20007

P2rx3 receptors are a class of ionotropic purinergic receptors that are expressed in sensory afferent neurons and have been shown to play essential roles in sensory transduction. However, little is known about how P2rx3 functions in neuronal morphogenesis and synaptic connectivity. Here, we found that P2rx3 is expressed by spiral ganglion neurons (SGNs) and hair cells during cochlear development. Using P2rx3 null mice combined with genetic sparse labeling, we discovered P2rx3 regulates SGN branch refinement, which is a function of P2rx3 distinguishable from the more conventionally-known role in neural transduction. These results offer new insights into how P2rx3 promotes auditory neuron maturation, which may be useful for endeavors aimed at regenerating lost auditory connections in hearing loss.

Long-term exposure to low-intensity environmental noise aggravates age-related hearing loss via disruption of cochlear ribbon synapses

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7407738/

https://www.ncbi.nlm.nih.gov/pubmed/32774726?dopt=Abstract

Long-term exposure to low-intensity environmental noise aggravates age-related hearing loss via disruption of cochlear ribbon synapses.

Am J Transl Res. 2020;12(7):3674-3687

Authors: Feng S, Yang L, Hui L, Luo Y, Du Z, Xiong W, Liu K, Jiang X

Abstract

Noise pollution is a major public hazard. Previous studies have shown that environmental noise affects the reorganization of the auditory cortex and leads to behavioral abnormality; however, the effects of long-term environmental noise exposure on the inner ear and hearing remain to be elucidated. In this study, we simulated environmental noise with a long-term 70 dB sound pressure level “white” noise, observed its effect on the inner ears of C57BL/6J mice, and developed an in vitro model for mechanistic studies. We found that environmental noise increased the hearing threshold, decreased the auditory response amplitude, and aggravated the range and extent of age-related hearing loss (ARHL), especially in the intermediate frequency band in mice. Cochlear ribbon synapse is the primary site of inner ear injury caused by environmental noise. We also verified, through an in vitro simulation of the excitatory toxicity of glutamate and aging effects, that the activation of NLRP3 inflammasome plays a vital role in the cochlear ribbon synaptic damage. Our results show that long-term exposure to low-intensity environmental noise can lead to hearing loss via the disruption of ribbon synapses, which is caused by an inflammatory reaction. Additionally, environmental noise can further aggravate the progression of ARHL. This study expounded the pathogenesis of the inner ear damage caused by environmental noise exposure and provides a new direction for the prevention and treatment of hearing loss.

PMID: 32774726 [PubMed – as supplied by publisher]

FGF22 promotes generation of cochlear ribbon synapses through downregulating MEF2D

https://www.aging-us.com/article/103042/text

ribbon synapses may be regulated by FGF22/calcium/CalN/MEF2D signaling, which implied novel therapeutic targets for hearing loss.

FGF22 promotes generation of ribbon synapses through downregulating MEF2D
Shuna Li1 , Jingchun He1 , Yupeng Liu1 , Jun Yang1
1 Department of Otolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
Received: January 22, 2020       Accepted: March 10, 2020       Published: April 9, 2020https://doi.org/10.18632/aging.103042

Repeated Moderate Sound Exposure Causes Accumulated Trauma to Cochlear Ribbon Synapses in Mice

https://www.sciencedirect.com/science/article/abs/pii/S0306452220300075?via%3Dihub

https://pubmed.ncbi.nlm.nih.gov/31935490/

Repeated Moderate Sound Exposure Causes Accumulated Trauma to Cochlear Ribbon Synapses in Mice
Yangtuo Luo 1, Tengfei Qu 2, Qingling Song 2, Yue Qi 2, Shukui Yu 2, Shusheng Gong 2, Ke Liu 3, Xuejun Jiang 4
Affiliations expand
PMID: 31935490 DOI: 10.1016/j.neuroscience.2019.12.049

Short-term NAD+ supplementation prevents hearing loss in mouse models of Cockayne syndrome

https://www.nature.com/articles/s41514-019-0040-z

Short-term NAD+ supplementation prevents hearing loss in mouse models of Cockayne syndrome
Mustafa N. Okur, Beatrice Mao, Risako Kimura, Scott Haraczy, Tracy Fitzgerald, Kamren Edwards-Hollingsworth, Jane Tian, Wasif Osmani, Deborah L. Croteau, Matthew W. Kelley & Vilhelm A. Bohr
npj Aging and Mechanisms of Disease volume 6, Article number: 1 (2020) Cite this article

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Current concepts in cochlear ribbon synapse formation

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6573016/

Current concepts in cochlear ribbon synapse formation
Thomas M Coate 1, M Katie Scott 2, Mansa Gurjar 1
Affiliations expand
PMID: 30592086 PMCID: PMC6573016 DOI: 10.1002/syn.22087

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