Development of cochlear potentials in the neonatal gerbil

McGuirt, Joan P.; Schmiedt, Richard A.; Schulte, Bradley A.

doi:10.1016/0378-5955(95)00015-v

Cited by 42 publications

(40 citation statements)

References 28 publications

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“…1). The above investigations have been supported by a number of other measurements in developing gerbils (McGuirt et al, 1995;Ryan and Woolf, 1992 ;Sanes et al, 1989;Schweitzer et al, 1996;Smith and Kraus, 1987;Woolf and Ryan, 1984Woolf et al, 1986;Yancey and Dallos, 1985).…”

Section: Introductionsupporting

confidence: 48%

Development of the base of the cochlea: place code shift in the gerbil

Mills

Rubel

1998

Hearing Research

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Distortion product otoacoustic emission measurements were made at 1/12 octave intervals before and after the injection of furosemide in gerbils aged 15 days after birth to adult, in order to obtain estimates of cochlear amplifier gain as a function of stimulus frequency. The frequency at which the gains went sharply to zero, defined as the`base cutoff frequency', increased from about 20 kHz to over 50 kHz during development. This increase provides further confirmation of the hypothesis that the place code changes during development in the basal part of the cochlea. If the measured base cutoff frequency is identified with the characteristic frequency at the basal end of the cochlea, as defined by electrophysiological measures, then these emission data can be used to generate a frequency-place map as a function of age. The derived place code shift is consistent with published electrophysiological measures, and can be used to extend these measures. Near the base cutoff frequency, the observed cochlear amplifier gain typically dropped sharply from a relative maximum to zero, over a distance of about a half octave. Specifically, this distance appeared to exhibit a curvilinear variation with age, reaching a maximum of 3/4 of an octave at 19^21 days. After transforming from frequency to place using the map derived from emissions, however, the distance between the extreme base and the place associated with the peak gain decreased monotonically from about 1.2 mm at age 15^19 days to 0.6 mm at maturity. This distance is assumed to be characteristic of the length of the active amplification zone for the cochlear amplifier in the base region. Over the same time period, there was approximately a doubling of the rate of amplification with distance from the base, so that the cochlear amplifier gain at the peak actually changed very little from 15 days to adult. z 1998 Published by Elsevier Science B.V. All rights reserved.

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Section: Introductionsupporting

confidence: 48%

Development of the base of the cochlea: place code shift in the gerbil

Mills

Rubel

1998

Hearing Research

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“…2(d)] not reaching adult ranges even by P28. The outer hair cells (OHCs), the main contributor of the CM potential (McGuirt et al, 1995), in the chinchilla are mature in appearance 24 h after birth (Harrison et al, 1996). Harrison et al (1996), however, noted the presence of vestigial kinocilia on OHCs located at the middle and apical turns of the cochlea on the first postnatal day (P0-1) as an indicator of cochlear immaturity.…”

Section: Maturation Of Hair Cell Function-cm Recordingsmentioning

confidence: 99%

Postnatal development of cochlear microphonic and compound action potentials in a precocious species, Chinchilla lanigera

Jones

Koka

Tollin

2011

The Journal of the Acoustical Society of America

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The development of sound-evoked responses in Chinchilla lanigera was studied from postnatal ages P0-1 (first 24 h) to adult. Cochlear microphonic (CMs) and compound action potentials (CAPs), representing ensemble sound-evoked activities of hair cells and auditory nerve fibers, respectively, were present as early as age P0-1. The data indicate that CM thresholds and sensitivities were generally adult-like (i.e., fall into adult ranges) at birth, but suprathreshold CM amplitudes remained below adult ranges through P28. CAP thresholds reached adult-like values between P7–P14, but the suprathreshold CAP amplitude continued to increase until ∼P28. The results confirm the auditory precociousness of the chinchilla.

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“…Animals were divided into ¢ve age groups based on endocochlear potential (EP) development in gerbil (Woolf et al, 1986 ;McGuirt et al, 1995) : 13 dab, 14 dab, 15 to 17 dab, 18 to 21 dab, and 23 to 60 dab. Table 1 provides the numbers of animals and neurons in each age group, as well as other pertinent information.…”

Section: Animal Preparationmentioning

confidence: 99%

“…The appearance of 2TS roughly coincided with the time when DPOAEs could ¢rst be measured in the gerbil (Norton et al, 1991 ;Mills et al, 1994, Mills andRubel, 1996). Suppression was not expected to be present at 13 dab when driven discharge activity required stimulus levels which were beyond the output limits of the suppressor-tone (105 dB SPL), and the endocochlear potential is severely reduced relative to adults (Woolf et al, 1986 ;McGuirt et al, 1995).…”

Section: Development Of Responses To Two-tone Stimulimentioning

confidence: 99%

“…Certain of these changes could a¡ect cochlear function through alterations of basilar membrane mass and sti¡-ness characteristics. Other changes, including a dramatic increase in the endocochlear potential (cat: Fernandez and Hinojosa, 1974;gerbil : Woolf et al, 1986;McGuirt et al, 1995;rat: Bosher and Warren, 1971), are thought to in£uence cochlear response properties through changes in the processes underlying the cochlear ampli¢er.…”

Section: Introductionmentioning

confidence: 99%

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Development of single- and two-tone responses of anteroventral cochlear nucleus neurons in gerbil

et al. 1998

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Responses of anteroventral cochlear nucleus (AVCN) neurons in developing gerbils were obtained to single-tone stimuli, and twotone stimuli elicited by best frequency probes presented over a range of intensities. Neurons displayed Type I, Type I/III, and Type III receptive field patterns. Best frequencies ranged from 1.5 to 10.0 kHz. Two-tone suppression (2TS) was first observed in 5 of 16 neurons examined at 14 dab, and in all neurons examined in gerbils aged 15 to 60 dab. Suppression areas grew larger, and discharge rate reductions became greater with age. Features of the two-tone responses that were highly correlated with single-tone responses across age groups include maximum rate reductions and suppression area thresholds. The intensity level of the CF probe-tone also influenced these features of 2TS. Maximum rate reductions to below spontaneous rate levels of activity were common across age groups. Results suggest that the cochlear amplifier is present and fundamentally adult-like by 15 dab for the regions of the cochlea coding the mid frequencies in gerbil. Over the subsequent week, contributions to the developing two-tone responses by the cochlear amplifier increase slightly. Two-tone responses are influenced by central inhibitory mechanisms as early as 14 dab. z 1998 Elsevier Science B.V. All rights reserved.

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Development of cochlear potentials in the neonatal gerbil

Cited by 42 publications

References 28 publications

Development of the base of the cochlea: place code shift in the gerbil

Development of the base of the cochlea: place code shift in the gerbil

Postnatal development of cochlear microphonic and compound action potentials in a precocious species, Chinchilla lanigera

Development of single- and two-tone responses of anteroventral cochlear nucleus neurons in gerbil

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