“Comparison of Cochlear Microphonics Magnitude with Broad and Narrow Band Stimuli in Healthy Adult Wistar Rats”

Fatemeh Heidari, Akram Pourbakht, Seyed Kamran Kamrava, Mohammad Kamali, Abbas Yousefi

Abstract


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Abstract

Objective: Cochlear microphonic (CM) is a cochlear AC electric field, recorded within, around, and remote from its sources. Nowadays it can contribute to the differential diagnosis of different auditory pathologies such as auditory neuropathy spectrum disorder (ANSD). The aim of this study was to compare CM waveforms (CMWs) and amplitudes with broad and narrow band stimuli in 25 healthy male young adult Wistar rats.

Methods: Using an extratympanic technique in ECochG (Electrocochleography) recording, CMWs in response to click and tonal stimuli with different octave frequencies were recorded at a high intensity level in subjects. The CMW amplitudes were calculated by a graphical user interface (GUI) designed in MATLAB. The data was analyzed by One-way ANOVA test.

Results: The CMW magnitude increased upon an increase in band width stimulation. Across tonal stimuli, the CMW amplitudes at lower frequency tones were larger than those at higher frequency tones. Those findings were statistically significant (P< 0.001).

Conclusion: This study found that CMW most likely is a reflection of spatial summation of voltage drops generated by hair cell groups in response to acoustic stimulation. In order to production nature of CM potentials as well as their very small magnitudes especially with tonal stimuli, thus, we recommend using click stimulation for CM potential recording especially in patient with ANSD that CM plays an important role in its differential diagnosis and follow up

Keywords


Cochlear microphonic potentials; Auditory neuropathy; Electrocochleography; Rats; Evoked potentials.

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References


Ashmore J. Cochlear outer hair cell motility. Physiol Rev. 2008; 88:173-210.

Dallos P. The active cochlea. J Neurosci. 1992; 12:4575-85.

Masood A, Teal PD, Hollitt C. A non-invasive Cochlear Microphonic measurement system. Med Eng Phys. 2012; 34:1191-5.

Dallos P, Cheatham MA. Production of cochlear potentials by inner and outer hair cells. J Acoust Soc Am. 1976; 60:510-2.

Hallworth R. Absence of voltage-dependent compliance in high-frequency cochlear outer hair cells. J Assoc Res Otolaryngol. 2007; 8:464-73.

Cheatham MA, Naik K, Dallos P. Using the cochlear microphonic as a tool to evaluate cochlear function in mouse models of hearing. J Assoc Res Otolaryngol. 2011; 12:113-25.

Santarelli R, Scimemi P, Dal Monte E, Arslan E. Cochlear microphonic potential recorded by transtympanic electrocochleography in normally-hearing and hearing-impaired ears. Acta Otorhinolaryngol Ital. 2006; 26:78-95.

Iwasa KH, Sul B. Effect of the cochlear microphonic on the limiting frequency of the mammalian ear. J Acoust Soc Am. 2008; 124:1607-12.

Shi W, Ji F, Lan L, Liang SC, Ding HN, Wang H, et al. Characteristics of cochlear microphonics in infants and young children with auditory neuropathy. Acta Otolaryngol. 2012 Feb;132(2):188-96.

Zhang M. Using concha electrodes to measure cochlear microphonic waveforms and auditory brainstem responses. Trends Amplif. 2010; 14:211-7.

Berlin CI, Bordelon J, St John P, Wilensky D, Hurley A, Kluka E, et al. Reversing click polarity may uncover auditory neuropathy in infants. Ear Hear. 1998; 19:37-47.

Deltenre P, Mansbach AL, Bozet C, Christiaens F, Barthelemy P, Paulissen D, et al. Auditory neuropathy with preserved cochlear microphonics and secondary loss of otoacoustic emissions. Audiol. 1999; 38:187-95.

Rance G, Beer DE, Cone-Wesson B, Shepherd RK, Dowell RC, King AM, et al. Clinical findings for a group of infants and young children with auditory neuropathy. Ear Hear. 1999; 20:238-52.

Starr A, Sininger Y, Nguyen T, Michalewski HJ, Oba S, Abdala C. Cochlear receptor (microphonic and summating potentials, otoacoustic emissions) and auditory pathway (auditory brain stem potentials) activity in auditory neuropathy. Ear Hear. 2001; 22:91-9.

Burkard R, Don M, Eggermont J. Auditory evoked potentials basic: principles and clinical application. Baltimore: Lippincott Williams & Wilkins; 2007.

Ghirri P, Liumbruno A, Lunardi S, Forli F, Boldrini A, Baggiani A, et al. Universal neonatal audiological screening: experience of the University Hospital of Pisa. Ital J Pediatr. 2011; 37:16.

Cheatham M, Zheng J, Huynh K, Du G, Gao J, Zuo J, et al. Cochlear function in mice with only one copy of the prestin gene. J Physiol. 2005; 569:229-41.

Hall J. New handbook of auditory evoked responses: Pearson Education; 2007.

Dallos P, Evans BN. High-frequency motility of outer hair cells and the cochlear amplifier. Sci. 1995; 267:2006-9.

Pickles JO. An introduction to the physiology of hearing. Bingley: Emerald; 2012.

Gelfand S. cochlear mechanisms and process. Hearing: an introduction to psychological and physiological acoustics. 5th ed. London: informa healthcare; 2010. p. 75.

Zhang M. Using a concha electrode to measure response patterns based on the amplitudes of cochlear microphonic waveforms across acoustic frequencies in normal-hearing subjects. Ear Hear. 2015; 36:53-60.




DOI: https://doi.org/10.22037/ijcn.v12i2.14554

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