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Updated: Aug 9, 2026
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Published on: March 17, 2017
The structure and function of actin in hair cells
The Journal of the Acoustical Society of America
|July 1, 1985
Summary
Actin protein in hair cell stereocilia provides rigidity, crucial for hearing. Damage to this structure from noise exposure can alter hearing response properties.
Area of Science:
- Cell Biology
- Auditory Neuroscience
- Biophysics
Background:
- Actin protein has recently been identified in hair cell stereocilia and cuticular plate.
- Research is ongoing to understand actin's structure, associated proteins, and function in these regions.
Purpose of the Study:
- To describe the structural organization of actin in hair cell stereocilia.
- To identify actin-associated proteins and their functional roles.
- To explore the link between actin's mechanical properties and auditory transduction.
Main Methods:
- Structural analysis of actin organization.
- Identification of actin-binding proteins.
- Functional assays relating stereocilia mechanics to cellular events.
Main Results:
- The paracrystalline array of actin imparts rigidity and stiffness to stereocilia, influencing their response properties.
- Noise exposure can damage the actin array, altering stereocilia properties.
- Changes in stereocilia shape due to actin filament shearing may link mechanical vibrations to mechano-electrical events.
Conclusions:
- Actin's structural role is critical for stereocilia function and auditory response.
- Stereocilia rigidity, influenced by actin, is essential for normal hearing.
- Actin-based mechanisms may be involved in auditory transduction and noise-induced hearing loss.
Related Concept Videos
01:22Hair Cells
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.
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.
01:26Introduction to Actin
Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle cells, while in non-muscle cells, it is lower and makes up around 1–5 percent of the total cell protein. Actin found in the unicellular amoebae and complex multicellular animals is around 80% similar, demonstrating their conservation over a billion years of evolution. Actin coding genes are conserved within species and across different species.
01:11Formation of Higher-order Actin Filaments
The polymerization of G-actin monomers into filamentous F-actin is a multi-step process. Once the F-actins are formed, they can bundle together in different arrangements to form higher-order networks and regulate cellular functions. Common examples include the formation of lamellipodia and filopodia at the cell's leading edge by actin reorganization in a migrating cell. The microvilli on the brush border epithelial cells are also formed through the F-actin network.
The high-order actin networks...
The high-order actin networks...
01:13Actin Polymerization and Cell Motility
Actin is a family of globular proteins that are highly abundant in eukaryotic cells. It makes up approximately 1-5% of total cell protein concentration. Actin monomers polymerize to form a complex network of polarized filaments, the actin cytoskeleton, that plays a crucial role in many cellular processes, including cell motility, division, endocytosis, and metastasis of cancer cells.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
01:16Accessory Structures of the Skin: Hair and Hair Follicles
Hair and hair follicles are integral components of the integumentary system. Hair is a filamentous structure composed mainly of a protein called keratin. It is found on the surface of the skin throughout the body, except for areas such as the palms of the hands and soles of the feet.
Hair is a keratinous filament growing out of the epidermis. It is primarily made of dead, keratinized cells. Hair strands originate at the epidermal penetration called the hair follicle. The hair shaft is the part...
Hair is a keratinous filament growing out of the epidermis. It is primarily made of dead, keratinized cells. Hair strands originate at the epidermal penetration called the hair follicle. The hair shaft is the part...