Related Experiment Videos
Patterns of hair cell loss in chick basilar papilla after intense auditory stimulation. Frequency organization
Insights
Intense sound exposure in young chicks caused hair cell loss in the basilar papilla, with frequency determining the location of damage. This reveals a similar acoustic response to mammals despite structural differences.
Area of Science:
- Auditory Neuroscience
- Ototoxicology
- Comparative Anatomy
Background:
- The avian basilar papilla, while morphologically distinct from the mammalian cochlea, serves as a model for studying auditory function.
- Understanding the effects of intense sound on auditory structures is crucial for preventing hearing loss.
Purpose of the Study:
- To investigate the effects of pure-tone acoustic overstimulation on hair cell populations in the chick basilar papilla.
- To determine the relationship between sound frequency and the location of induced hair cell damage.
- To predict the frequency organization of the chick basilar papilla based on acoustic trauma patterns.
Main Methods:
- Ten-day-old chicks were exposed to pure tones (500, 1500, or 3000 Hz) at 125 dB SPL for 12 hours.
- Basilar papillae were harvested 10 days post-exposure, embedded in plastic, and sectioned.
- Hair cells were counted at 100-micrometer intervals along the basilar papilla.
Main Results:
- Hair cell loss was observed along the basilar papilla following intense sound exposure.
- The location of hair cell loss demonstrated a systematic, log-linear relationship with the frequency of the pure-tone stimulus.
- This frequency-specific damage pattern allowed for the prediction of tonotopic organization in the chick basilar papilla.
Conclusions:
- The chick basilar papilla exhibits a tonotopic organization that can be mapped using acoustic trauma.
- Despite significant morphological differences, the avian auditory system's response to intense sound is comparable to that of the mammalian cochlea.
- These findings contribute to our understanding of auditory system vulnerability and frequency mapping across species.
Abstract:
Ten-day-old chicks were continuously exposed to pure tones (500, 1 500, or 3 000 Hz) at 125 dB SPL for 12 hours and sacrificed 10 days after exposure. The basilar papillae were embedded in plastic, sectioned and hair cells were counted at 100-mum intervals throughout the length of the papilla. The position of hair cell loss along the basilar membrane varied systematically as a log-linear function with the frequency of stimulation. This systematic relationship was used to predict the frequency organization of the chick basilar papilla. It is concluded that although the avian basilar papilla differs greatly in morphological detail from the mammalian cochlea, its response to intense acoustic stimulation is quite similar.