Related Experiment Video
Updated: Mar 20, 2026
09:54
Morphological and Functional Evaluation of Ribbon Synapses at Specific Frequency Regions of the Mouse Cochlea
Published on: May 10, 2019
12.8K
Coding Deficits in Noise-Induced Hidden Hearing Loss May Stem from Incomplete Repair of Ribbon Synapses in the
Lijuan Shi1, Yin Chang1, Xiaowei Li1
1Department of Physiology, Medical College of Southeast University Nanjing, China.
Frontiers in Neuroscience
|June 3, 2016
Summary
Noise-induced damage to auditory nerve synapses, particularly those connected to low-spontaneous rate (SR) fibers, can cause hidden hearing loss. Insufficient synapse repair, not just fiber loss, leads to coding deficits affecting hearing in noise.
Area of Science:
- Neuroscience
- Auditory Neuroscience
- Otoacoustic Emissions
Background:
- Noise exposure can damage synapses between inner hair cells (IHCs) and auditory nerve fibers (ANFs) without causing permanent threshold shift (PTS).
- Synapses with low spontaneous rate (SR) ANFs are particularly vulnerable, impacting temporal processing and hearing in noise, a condition known as "hidden hearing loss".
Purpose of the Study:
- To investigate neural coding deficits at the single unit level following noise-induced damage to IHC-ANF synapses.
- To determine if coding deficits are solely due to the loss of low-SR ANFs or also involve synaptic repair.
Main Methods:
- Analysis of neural coding at the single unit level in response to noise exposure.
- Assessment of synaptic integrity and function post-noise exposure.
Main Results:
- Initial loss of low-SR ANFs did not significantly alter all neural coding aspects.
- Further coding deficits emerged with synaptic re-establishment, indicating issues with repair.
- Observed deficits include reduced driven spike rate for intensity coding and impaired temporal coding (latency, spike rate recovery).
Conclusions:
- Hidden hearing loss may stem from insufficient repair of noise-disrupted IHC-ANF synapses, rather than solely from the loss of low-SR ANFs.
- Synaptopathy, or synaptic dysfunction, is a key factor in the coding deficits observed in hidden hearing loss.
Related Concept Videos
01:15Auditory Pathway
8.6K
Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea.
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking...
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking...
8.6K
01:22Hair Cells
46.3K
Hair cells are the sensory receptors of the auditory system—they transduce mechanical sound waves into electrical energy that the nervous system can understand. Hair cells are located in the organ of Corti within the cochlea of the inner ear, between the basilar and tectorial membranes. The actual sensory receptors are called inner hair cells. The outer hair cells serve other functions, such as sound amplification in the cochlea, and are not discussed in detail here.
46.3K
01:13The Cochlea
52.3K
The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane.
52.3K
01:31Hearing
58.5K
When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness.
58.5K
00:50Unrenewable Cells
3.0K
In humans, the photoreceptor cells of the eye and sensory hair cells of the ear lack stem cells. These cells are thus unrenewable and cannot be replaced when they are damaged or destroyed.
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of...
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of...
3.0K