scholarly journals Effect of auditory-nerve response variability on estimates of tuning curves

2007 ◽  
Vol 122 (6) ◽  
pp. EL203-EL209 ◽  
Author(s):  
Ananthakrishna Chintanpalli ◽  
Michael G. Heinz
2005 ◽  
Vol 93 (1) ◽  
pp. 557-569 ◽  
Author(s):  
Annette M. Taberner ◽  
M. Charles Liberman

The availability of transgenic and mutant lines makes the mouse a valuable model for study of the inner ear, and a powerful window into cochlear function can be obtained by recordings from single auditory nerve (AN) fibers. This study provides the first systematic description of spontaneous and sound-evoked discharge properties of AN fibers in mouse, specifically in CBA/CaJ and C57BL/6 strains, both commonly used in auditory research. Response properties of 196 AN fibers from CBA/CaJ and 58 from C57BL/6 were analyzed, including spontaneous rates (SR), tuning curves, rate versus level functions, dynamic range, response adaptation, phase-locking, and the relation between SR and these response properties. The only significant interstrain difference was the elevation of high-frequency thresholds in C57BL/6. In general, mouse AN fibers showed similar responses to other mammals: sharpness of tuning increased with characteristic frequency, which ranged from 2.5 to 70 kHz; SRs ranged from 0 to 120 sp/s, and fibers with low SR (<1 sp/s) had higher thresholds, and wider dynamic ranges than fibers with high SR. Dynamic ranges for mouse high-SR fibers were smaller (<20 dB) than those seen in other mammals. Phase-locking was seen for tone frequencies <4 kHz. Maximum synchronization indices were lower than those in cat but similar to those found in guinea pig.


1999 ◽  
Vol 82 (2) ◽  
pp. 1019-1032 ◽  
Author(s):  
William S. Rhode

The dorsal cochlear nucleus receives input from the auditory nerve and relays acoustic information to the inferior colliculus. Its principal cells receive two systems of inputs. One system through the molecular layer carries multimodal information that is processed through a neuronal circuit that resembles the cerebellum. A second system through the deep layer carries primary auditory nerve input, some of which is relayed through interneurons. The present study reveals the morphology of individual interneurons and their local axonal arbors and how these inhibitory interneurons respond to sound. Vertical cells lie beneath the fusiform cell layer. Their dendritic and axonal arbors are limited to an isofrequency lamina. They give rise to pericellular nests around the base of fusiform cells and their proximal basal dendrites. These cells exhibit an onset-graded response to short tones and have response features defined as type II. They have tuning curves that are closed contours (0 shaped), thresholds ∼27 dB SPL, spontaneous firing rates of ∼0 spikes/s, and they respond weakly or not at all to broadband noise, as described for type II units. Their responses are nonmonotonic functions of intensity with peak responses between 30 and 60 dB SPL. They also show a preference for the high-to-low direction of a frequency sweep. It has been suggested that these circuits may be involved in the processing of spectral cues for the localization of sound sources.


1967 ◽  
Vol 42 (6) ◽  
pp. 1341-1342 ◽  
Author(s):  
N. Y. S. Kiang ◽  
M. B. Sachs ◽  
W. T. Peake

2008 ◽  
Vol 100 (5) ◽  
pp. 2889-2898 ◽  
Author(s):  
Andrei N. Temchin ◽  
Nola C. Rich ◽  
Mario A. Ruggero

Frequency-threshold tuning curves were recorded in thousands of auditory-nerve fibers (ANFs) in chinchilla. Synthetic tuning curves with 21 characteristic frequencies (187 Hz to 19.04 kHz, spaced every 1/3 octave) were constructed by averaging individual tuning curves within 2/3-octave frequency bands. Tuning curves undergo a gradual transition in symmetry at characteristic frequencies (CFs) of 1 kHz and an abrupt change in shape at CFs of 3–4 kHz. For CFs ≤3 kHz, the lower limbs of tuning curves have similar slopes, about −18 dB/octave, but the upper limbs have slopes that become increasingly steep with increasing frequency and CF. For CFs >4 kHz, tuning curves normalized to the CF are nearly identical and consist of three segments. A tip segment, within 30–40 dB of CF threshold, has lower- and upper-limb slopes of −60 and +120 dB/octave, respectively, and is flanked by a low-frequency (“tail”) segment, with shallow slope, and a terminal high-frequency segment with very steep slope (several hundreds of dB/octave). The tuning curves of fibers innervating basal cochlear sites closely resemble basilar-membrane tuning curves computed with low isovelocity criteria. At the apex of the chinchilla cochlea, frequency tuning is substantially sharper for ANFs than for available recordings of organ of Corti vibrations.


1982 ◽  
Vol 91 (2) ◽  
pp. 205-208 ◽  
Author(s):  
A. Rubinstein ◽  
H. Sohmer

Recording the response of the auditory nerve (W1) in neonates can contribute to the diagnostic distinction between audiological-otological versus neurological pathology. If W1 latency were subject to relatively rapid shortening in the hours directly after birth, inconsistencies in the literature might be clarified. The purpose of this research was to study W1 in neonates one to eight hours old in order to determine if significant latency changes occur during this period. Auditory nerve-brainstem responses were recorded in 40 full-term neonates and in 12 normal adults. W1 latency in 1- to 3-hour-old neonates was 1.81 ± 0.28 ms and 1.77 ± 0.18 ms in 7- to 8-hour-old neonates. This difference was not significant. In adults, W1 latency was significantly shorter (1.36 ± 0.06 ms). These findings indicate that auditory nerve latency is about 0.43 ms longer at birth than in the adult and that the latency does not shorten significantly during the first hours after birth.


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