Effects of High-Frequency Sound on Electrochemical Potential Using the Single-Barrel Method in Guinea Pigs

Abstract

There are only a few studies investigating the effects of ultrasound on hearing. This paper reports on an experimental investigation on the effect of the longtime exposure to a moderate sound pressure level, high-frequency sound of 16 kHz on the guinea pig inner ear using electrophysiological methods. A decrease of the absolute value of negative potential was observed in the endo-cochlear potential (EP). The effects of high-frequency sound on EP and electrochemical potential could be explained by a change in the K⁺ permeability of hair cells.

Effects of High-Frequency Sound on the Guinea Pig Cochlea

“…In this and a pre vious report [7], 16-kHz sound exposure had the strongest effect in negative potential of EP. Thus, we investigated the change of the electrochemical potential of KC1 in duced by 16-kHz tone exposure [8], The results of the dif ference in KC1 concentration between that of control and 100-dB exposure was 10.3 mM and the difference in KC1 concentration between that of control and 90-d B expo sure was 4.3 mM.…”

“…10 were used in experiment Iep out in a soundproof room of 4 X 2.5 X 3 m (sound insulation more than 50 dB at 1 kHz). The apparatus used for the noise exposures were described already [7,8]. The guinea pigs were put in a small wire cage, and their right ears faced the speaker at 10 cm distance.…”

“…After 16-kHz tone exposure for 40 h, we investigated the electrochemi cal potential using single-barrel electrode with the aim of speculating on K+ concentration in the endolymph of the cochlea [8].…”

Effect of 4 kHz Tone Exposure on the Guinea Pig Inner Ear: Relation in the Change of Cochlear Microphonics, Action Potential, Electrochemical Potential and K⁺ Ion Concentration Induced by Noise Exposure

“…when tempo rary threshold shift, decrease in cochlear microphonics (CM) occur [1,2], These effects will cause a permanent change in the function of the inner ear. In our previous studies, we have investigated the effect of low-frequency ultrasound on the inner ear experimentally [3,4], It was observed by us as well as by another author [5] that the change in the guinea pig inner ear function was prominent by tone exposure to 4-6 kHz [1,5, 6], So, we examined 4 kHz tone exposure to guinea pigs using CM, action potential (AP), electrochemical potential with single-bar rel K+-sensitive liquid-membrane electrode [4] and the chemical potential with double-barrel K+-sensitive liq uid-membrane electrode. By this experimental setup, we planned to see if there were any correlative changes in the above parameters of the inner ear.…”