Noise-induced hearing loss correlates with inner ear hair cell decrease in larval zebrafish

Area of Science:

• Auditory Neuroscience
• Developmental Biology
• Environmental Toxicology

Background:

• Anthropogenic noise is a global pollutant impacting animal auditory systems.
• Little is known about noise effects on auditory function during early development.
• Zebrafish (Danio rerio) are a key model for vertebrate inner ear development and hearing research.

Purpose of the Study:

• To investigate the effects of chronic white noise exposure on larval zebrafish inner ear function and morphology.
• To assess noise impacts on auditory-evoked sensorimotor responses in early development.
• To understand the relationship between structural and functional changes in the developing auditory system due to noise pollution.

Main Methods:

• Larval zebrafish were chronically exposed to white noise.
• Saccular sensitivity and morphology were measured at 3 and 5 days post-fertilization (dpf).
• Auditory-evoked swimming responses were assessed using the prepulse inhibition (PPI) paradigm at 5 dpf.

Main Results:

• Noise-exposed larvae showed elevated microphonic potential thresholds at low frequencies (100, 200 Hz).
• The PPI paradigm indicated hypersensitization and a threshold shift at 200 Hz in noise-exposed fish.
• Auditory changes correlated with reduced saccular hair cell numbers and smaller epithelium area.

Conclusions:

• Chronic noise exposure negatively impacts inner ear structure and function in larval zebrafish.
• Noise pollution affects auditory sensitivity and sensorimotor responses during early development.
• These findings underscore the need to study environmental noise impacts on developing sensory systems and behavioral responses to sound.