Ultrasonic electrocochleography in guinea pig.

Area of Science:

• Auditory Neuroscience
• Otoacoustic Emissions
• Sensory Physiology

Background:

• Understanding ultrasonic stimuli perception (USP) in humans is crucial for auditory research.
• Investigating the physiological basis of high-frequency sound detection is an ongoing challenge.

Purpose of the Study:

• To investigate the perception of ultrasonic stimuli (USP) in humans.
• To determine if a specialized sensory organ exists for USP.
• To explore the neural pathways involved in high-frequency sound detection.

Main Methods:

• Guinea pig cochleae were stimulated via bone conduction at ultrasonic frequencies (98.8 and 143.5 kHz).
• Cochlear potentials, including CM, SP, and AP, were recorded from the basal turn.
• The influence of physiological factors (asphyxia, ethacrynic acid, hypothermia) and kanamycin treatment on cochlear potentials was assessed.

Main Results:

• Cochlear potentials (CM, SP, AP) were recorded from the basal turn in response to ultrasonic stimuli.
• These potentials were modulated by asphyxia, ethacrynic acid, hypothermia, and interstimulus interval.
• Kanamycin treatment significantly reduced AP amplitude and increased AP latency, indicating damage to hair cells.

Conclusions:

• Ultrasonic stimuli do not require a special sense organ for detection.
• High-frequency sounds activate hair cells in the basal turn of the cochlea.
• Cochlear potentials provide insights into the physiological mechanisms of ultrasonic sound perception.