Acoustically responsive fibers in the vestibular nerve of the cat

McCue, M. P.; Jj, Guinan

doi:10.1523/jneurosci.14-10-06058.1994

Cited by 303 publications

(203 citation statements)

References 48 publications

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“…Spontaneous or sound-evoked responses also differed from wildtype olivocochlear efferents or vestibular neurons 50 . If we indeed recorded from such units, their responses must also have been affected by the mutation.…”

Section: Recordings Of Cochlear Potentials (Electrocochleography) Abmentioning

confidence: 92%

Hearing requires otoferlin-dependent efficient replenishment of synaptic vesicles in hair cells

et al. 2010

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At the first auditory synapse in mammals, one ribbon-type AZ of the IHC drives one postsynaptic spiral ganglion neuron (SGN) to spike at rates exceeding 100 Hz in silence and 1 kHz upon sound onset 1, 2 . Moreover, SGNs sustain firing rates of several hundred Hz during ongoing acoustic stimulation. In such a steady state, vesicle replenishment has to balance vesicle fusion at the IHC AZ. Accordingly, high rates of initial and sustained exocytosis have been found in hair cells [3][4][5][6][7][8] . Ribbon-type AZs of IHCs replenish readily releasable vesicles at hundreds of Hz over several seconds of stimulation, faster than ribbon synapses in the eye 9-15 and most non-ribbon-type AZs 16(but see ref. 17). This efficient vesicle re-supply maintains a large standing pool of fusion competent synaptic vesicles, which appears to be critical for reliable and temporally precise sound encoding [18][19][20] . and Otof +/+ mice ( Fig. 2a-b The observations of normal RRP size after resting the synapse for more than 30 seconds and of reduced vesicle re-supply during ongoing stimulation prompted us to explore RRP recovery from depletion in paired-pulse experiments (Fig. 3a). RRP recovery, assessed as the paired-pulse ratio for different inter-pulse intervals, was impaired in Otof Pga/Pga mice (Fig. 3b). This indicated a deficit in vesicle replenishment also in the rest period between stimuli. The ΔC m pattern elicited by trains of ten short (10 ms) depolarizations demonstrates the exocytosis phenotype found after a period of rest (30 s voltage-clamp at -84 mV): normal RRP exocytosis but subsequent failure (Fig. 3c). Studying the C m decline after exocytosis we observed normal endocytic membrane retrieval (Fig. 3d). Normal synaptic ultrastructure in Otof Pga/Pga IHCsIn order to explore whether a docking or a priming defect underlies the impairment of vesicle replenishment at Otof Pga/Pga IHC synapses, we studied their ultrastructure using electron microscopy (EM). Both, EM of single ultrathin sections (perpendicular to the 7 plasma membrane and the long axis of the ribbon; Supplementary Fig. 2) as well as EM tomography (Fig. 3e-f High-resolution EM tomography ( Fig. 3e-f) was used to measure the distance of membrane-proximal synaptic vesicles (labeled orange in Fig. 3f) from the plasma membrane under both conditions. The average membrane-membrane distance was approximately 6 nm regardless of condition and genotype (Supplementary Reduced rates but maintained size variability of EPSCsThe stark contrast between the absence of auditory neuron population responses in vivo (Fig. 1) (Fig. 4a-b). We pooled the data from recordings in 5. Fig. 4h-i; Kolmogorov-Smirnov test, p = 0.14). Moreover, we detected action potential generation by recording action currents in the loose-patch configuration (Fig. 4g). Together these results suggest that Otof Pga/Pga synapses should be capable of encoding sound into spiking activity in auditory nerve fibers, albeit at lower rates.In addition, we recorded from SGNs of Otof -/-mice of the same age a...

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Section: Recordings Of Cochlear Potentials (Electrocochleography) Abmentioning

confidence: 92%

Hearing requires otoferlin-dependent efficient replenishment of synaptic vesicles in hair cells

et al. 2010

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“…2 A, SA) (Cohen and Winn, 1967), an otolith organ that also responds to acoustic stimuli in terrestrial vertebrates (Lewis et al, 1982;McCue and Guinan, 1994). Eighth nerve primary afferents (Fig.…”

Section: Methodsmentioning

confidence: 99%

Temporal Coding of Concurrent Acoustic Signals in Auditory Midbrain

Bodnar

Bass

1997

J. Neurosci.

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A fundamental problem faced by the auditory system of humans and other vertebrates is the segregation of concurrent vocal signals. To discriminate between individual vocalizations, the auditory system must extract information about each signal from the single temporal waveform that results from the summation of the simultaneous acoustic signals. Here, we present the first report of midbrain coding of simultaneous acoustic signals in a vocal species, the plainfin midshipman fish, that routinely encounters concurrent vocalizations. During the breeding season, nesting males congregate and produce longduration, multiharmonic mate calls that overlap, producing beat waveforms. Neurophysiological responses to two simultaneous tones near the fundamental frequencies of natural calls reveal that midbrain units temporally code the difference frequency (dF). Many neurons are tuned to a specific dF; their selectivity overlaps the range of dFs for naturally occurring acoustic beats.Beats and amplitude-modulated (AM) signals are also coded differently by most units. Although some neurons exhibit differential tuning for beat dFs and the modulation frequencies (modFs) of AM signals, others exhibit similar temporal selectivity but differ in their degree of synchronization to dFs and modFs. The extraction of dF information, together with other auditory cues, could enable the detection and segregation of concurrent vocalizations, whereas differential responses to beats and AM signals could permit discrimination of beats from other AM-like signals produced by midshipman. A central code of beat dFs may be a general vertebrate mechanism used for coding concurrent acoustic signals, including human vowels.

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“…Sound-evoked vestibular responses have been well documented in humans and animal models (Bickford et al 1964;Carey et al 2004;Curthoys et al 2006;McCue and Guinan 1994;Murofushi et al 1995;Tullio 1929;Young et al 1977;Zhou et al , 2005Zhou et al , 2007Xu et. al.…”

Section: Introductionmentioning

confidence: 99%

Frequency Tuning of the Cervical Vestibular-Evoked Myogenic Potential (cVEMP) Recorded from Multiple Sites along the Sternocleidomastoid Muscle in Normal Human Subjects

Wei

Jeffcoat

Mustain

et al. 2012

JARO

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Frequency tuning of tone burst-evoked myogenic potentials recorded from the sternocleidomastoid muscle (cervical VEMP or cVEMP) is used clinically to assess vestibular function. Understanding the characteristics of cVEMP is important for improving the specificity of cVEMP testing in diagnosing vestibular deficits. In the present study, we analyzed the frequency tuning properties of the cVEMPs by constructing detailed tuning curves and examining their morphology and dependence on SCM tonic level, sound intensity, and recording site along the SCM. Here we report two main findings. First, by employing nine tone frequencies between 125 and 4,000 Hz, some tuning curves exhibited two distinct peaks, which cannot be modeled by a single mass spring system as previously suggested. Instead, the observed tuning is better modeled as linear summation of two mass spring systems, with resonance frequencies at 300 and~1,000 Hz. Peak frequency of cVEMP tuning curves was not affected by SCM tonic level, sound intensity, and location of recording site on the SCM. However, sharpness of cVEMP tuning was increased at lower sound intensities. Second, polarity of cVEMP responses recorded from the lower quarter of the SCM was reversed as compared to that at the two upper sites. While more studies are needed, these results suggest that cVEMP tuning is mediated through multiple generators with different resonance frequencies. Future studies are needed to explore implications of these results on development of selective VEMP tests and determine the nature of polarity inversion at the lower quarter of SCM.

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Acoustically responsive fibers in the vestibular nerve of the cat

Cited by 303 publications

References 48 publications

Hearing requires otoferlin-dependent efficient replenishment of synaptic vesicles in hair cells

Hearing requires otoferlin-dependent efficient replenishment of synaptic vesicles in hair cells

Temporal Coding of Concurrent Acoustic Signals in Auditory Midbrain

Frequency Tuning of the Cervical Vestibular-Evoked Myogenic Potential (cVEMP) Recorded from Multiple Sites along the Sternocleidomastoid Muscle in Normal Human Subjects

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