Related Experiment Video
Updated: Jun 20, 2026
10:09
In Ovo and Ex Ovo Methods to Study Avian Inner Ear Development
Published on: June 16, 2022
Development and regeneration of the inner ear
Tao Kwan1, Patricia M White, Neil Segil
1House Ear Institute, Gonda Division of Cell Biology and Genetics, Los Angeles, California, USA.
Annals of the New York Academy of Sciences
|August 19, 2009
Summary
Mammalian cochlear hair cell regeneration fails because supporting cells do not divide. Understanding cell division and differentiation mechanisms may unlock therapeutic regeneration for hearing restoration.
Area of Science:
- Oto-neurology
- Developmental biology
- Regenerative medicine
Background:
- Sensory hair cell loss is a primary cause of human deafness.
- Mammalian cochleae lack hair cell regeneration, unlike birds.
- Current treatments for deafness involve prosthetics like hearing aids.
Purpose of the Study:
- To investigate the molecular mechanisms of hair cell regeneration failure in mammals.
- To understand cell division control and differentiation during cochlear development.
- To identify potential therapeutic targets for inducing hair cell regeneration.
Main Methods:
- Review of molecular mechanisms regulating cell proliferation in embryogenesis and postnatal development.
- Discussion of cell cycle inhibitors (Cip/Kip) and Notch signaling in supporting cell stability.
- Analysis of recent findings on latent regenerative capacity in mammalian supporting cells.
Main Results:
- Mammalian supporting cells normally do not divide or transdifferentiate upon hair cell loss.
- Cip/Kip inhibitors and Notch signaling are key regulators of supporting cell stability.
- Early postnatal mammalian supporting cells show a latent potential for division and differentiation.
Conclusions:
- Understanding molecular pathways controlling cell division and differentiation is crucial for addressing hair cell loss.
- Mammalian supporting cells are promising therapeutic targets for regenerative strategies.
- Inducing regeneration in supporting cells could restore hearing in cases of deafness.
Related Concept Videos
01:16Anatomy of the Ear
Auditory sensation, commonly called hearing, involves the transformation of sonic waves into neural impulses facilitated by the structures of the auditory organ. The prominent, flesh-like structure on the side of the head, called the auricle, directs sound waves towards the auditory canal. The auricle is often mislabeled as the pinna, a term more aligned with mobile structures like a feline's external ear. The auditory canal penetrates the cranium via the external auditory meatus of the...
01:17Auditory Perception
The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a...
01:15Auditory Pathway
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 the...
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the...
01:13The Cochlea
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.
01:15Equilibrium and Balance
The inner ear assumes dual functionalities of auditory perception and equilibrium maintenance. The vestibule is the organ responsible for balance. This organ contains mechanoreceptors, specifically hair cells, endowed with stereocilia, which aid in deciphering information regarding the position and motion of our heads. Two intrinsic components, the utricle and saccule, help perceive head position, while the semicircular canals track head movement. Neurological messages initiated in the...
01:15Neurogenesis and Regeneration of Nervous Tissue
In the CNS, neurogenesis, the birth of new neurons from stem cells, is limited to the hippocampus in adults. In other regions of the brain and spinal cord, neurogenesis is almost non-existent due to inhibitory influences from neuroglia, especially oligodendrocytes, and the absence of growth-stimulating cues. The myelin produced by oligodendrocytes in the CNS inhibits neuronal regeneration. Furthermore, astrocytes proliferate rapidly after neuronal damage, forming scar tissue that physically...