Final answer:
The ion channels in the hair cells of the mammalian cochlea are mechanosensitive ion channels. These channels open when stereocilia are bent by sound, allowing ion influx that depolarizes the hair cell membrane and initiates an auditory nerve impulse.
Step-by-step explanation:
The ion channels found in the hair cells of the mammalian cochlea are mechanosensitive ion channels. These specialized gated ion channels respond to the mechanical deformation of the plasma membrane. The stereocilia of the hair cells are linked to these channels through hair-like tethers that open the ion channels when the stereocilia are bent by sound-induced vibrations.
The stereocilia are critical components in the process of auditory transduction. They are arranged from tallest to shortest and connected by protein fibers that cause them to move as a unit when displaced. This mechanical movement triggers the opening of the mechanosensitive ion channels, leading to hair cell membrane depolarization and the initiation of nerve impulses that are transmitted to the cochlear nerve.
These impulses are what ultimately enable us to perceive sound. The difference in the frequency of incoming sounds is discerned by the location of the hair cells that are stimulated, as the basilar membrane of the cochlea vibrates differentially to different sound frequencies. This elegant system allows for the precise detection and communication of auditory information to the brain.