Answer :
Final answer:
At high frequencies, action potentials maintain a constant size, and information about stimuli is encoded by the frequency of these action potentials. More intense sounds produce larger receptor potentials, leading to a higher frequency of action potentials, enabling the auditory system to interpret different sound intensities and frequencies.
Explanation:
At high frequencies, action potentials in neurons convey information not by varying in size but by changing the rate at which they occur. Due to the all-or-none nature of action potentials, these electrical impulses maintain a consistent magnitude regardless of stimulus intensity. Instead, the information about the intensity of a stimulus, such as sound, is encoded by the frequency of action potentials.
For example, in the auditory system, the cochlea transduces sound waves into electrical signals. More intense sounds produce larger receptor potentials in hair cells, triggering more frequent release of neurotransmitters like glutamate, which in turn increases the rate of action potentials in auditory nerve fibers. Research by Wever & Bray (1930) indicated the existence of a temporal code relating the frequency of sound waves to the rate of action potential firing in the cochlear nerve.
This coding allows the brain to interpret different sound frequencies and intensities. The cochlea has a specialized structure where different regions on the basilar membrane are sensitive to various sound frequencies, resulting in activation of corresponding hair cells that signal the auditory nerve with distinct action potential patterns.Overall, neurons use this method of frequency coding, both for the pitch and intensity of sounds, efficiently communicating complex auditory information to the brain for processing.
