Which hair cells are primarily associated with cochlear amplification?

Which hair cells are primarily associated with cochlear amplification?

• A. Inner hair cells
• B. Supporting cells
• C. Outer hair cells
• D. Basilar membrane

Answer: (C)

Cochlear amplification is driven by the outer hair cells. These cells can change their length in response to electrical potentials—a property called electromotility—thanks to the motor protein prestin in their membranes. When they contract and expand, they feed back onto the organ of Corti and boost the motion of the basilar membrane at specific frequencies, especially for faint sounds, making the ear more sensitive and sharpening frequency tuning. Inner hair cells are the primary sensory transducers that convert mechanical motion into neural signals, but they don’t actively amplify vibrations. Supporting cells provide structural and metabolic support, not amplification, and the basilar membrane is a passive mechanical structure, not a cell.

Cochlear amplification is driven by the outer hair cells. These cells can change their length in response to electrical potentials—a property called electromotility—thanks to the motor protein prestin in their membranes. When they contract and expand, they feed back onto the organ of Corti and boost the motion of the basilar membrane at specific frequencies, especially for faint sounds, making the ear more sensitive and sharpening frequency tuning. Inner hair cells are the primary sensory transducers that convert mechanical motion into neural signals, but they don’t actively amplify vibrations. Supporting cells provide structural and metabolic support, not amplification, and the basilar membrane is a passive mechanical structure, not a cell.