Spike timing in auditory-nerve fibers during spontaneous activity and phase locking

Synapse ◽  
2016 ◽  
Vol 71 (1) ◽  
pp. 5-36 ◽  
Author(s):  
Peter Heil ◽  
Adam J. Peterson
Keyword(s):  
Spontaneous Activity ◽  
Auditory Nerve ◽  
Phase Locking ◽  
Nerve Fibers ◽  
Spike Timing ◽  
Auditory Nerve Fibers

Pathophysiology of Tinnitus

1984 ◽  
Vol 93 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Aage R. Møsller
Keyword(s):  
Auditory Nerve ◽  
Neural Coding ◽  
Temporal Pattern ◽  
Phase Locking ◽  
Cranial Nerves ◽  
Nerve Fibers ◽  
Complex Sounds ◽  
Ephaptic Transmission ◽  
Recent Developments ◽  
Auditory Nerve Fibers

The hypothesis is presented that certain forms of tinnitus are related to abnormal phase-locking of discharges in groups of auditory nerve fibers. Recent developments in auditory neurophysiology have shown that neural coding of the temporal pattern of sounds plays an important role in the analysis of complex sounds. In addition, it has been demonstrated that when some other cranial nerves are damaged, artificial synapses can occur between individual nerve fibers such that ephaptic transmission between nerve fibers is facilitated. Such “crosstalk” between auditory nerve fibers is assumed to result in phase-locking of the spontaneous activity of groups of neurons which in the absence of external sounds creates a neural pattern that resembles that evoked by sounds.

First-Spike Timing of Auditory-Nerve Fibers and Comparison With Auditory Cortex

1997 ◽  
Vol 78 (5) ◽  
pp. 2438-2454 ◽  
Author(s):  
Peter Heil ◽  
Dexter R. F. Irvine
Keyword(s):  
Auditory Cortex ◽  
Auditory Nerve ◽  
Rise Time ◽  
Peak Pressure ◽  
Inverse Function ◽  
Nerve Fibers ◽  
Spike Timing ◽  
Maximum Acceleration ◽  
Minimum Latency ◽  
Auditory Nerve Fibers

Heil, Peter and Dexter R. F. Irvine. First-spike timing of auditory-nerve fibers and comparison with auditory cortex. J. Neurophysiol. 78: 2438–2454, 1997. The timing of the first spike of cat auditory-nerve (AN) fibers in response to onsets of characteristic frequency (CF) tone bursts was studied and compared with that of neurons in primary auditory cortex (AI), reported previously. Tones were shaped with cosine-squared rise functions, and rise time and sound pressure level were parametrically varied. Although measurement of first-spike latency of AN fibers was somewhat compromised by effects of spontaneous activity, latency was an invariant and inverse function of the maximum acceleration of peak pressure (i.e., a feature of the 2nd derivative of the stimulus envelope), as previously found in AI, rather than of tone level or rise time. Latency-acceleration functions of all AN fibers were of very similar shape, similar to that observed in AI. As in AI, latency-acceleration functions of different fibers were displaced along the latency axis, reflecting differences in minimum latency, and along the acceleration axis, reflecting differences in sensitivity to acceleration [neuronal transient sensitivity (S)]. S estimates increased with spontaneous rate (SR), but values of high-SR fibers exceeded those in AI. This suggests that S estimates are biased by SR per se, and that unbiased true S values would be less tightly correlated with response properties covarying with SR, such as firing threshold. S estimates varied with CF in a fashion similar to the cat's audiogram and, for low- and medium-SR fibers, matched those for AI neurons. Minimum latency decreased with increasing SR and CF. As in AI, the standard deviation of first-spike timing (SD) in AN was also an inverse function of maximum acceleration of peak pressure. The characteristics of the increase of SD with latency in a given AN fiber/AI neuron and across AN fibers/AI neurons revealed that the precision of first-spike timing to some stimuli can actually be higher in AI than in AN. The data suggest that the basic characteristics of the latency-acceleration functions of transient onset responses seen in cortex are generated at inner hair cell–AN fiber synapses. Implications for signal processing in the auditory system and for first-spike generation and adaptation in AN are discussed.

scholarly journals Threshold Tuning Curves of Chinchilla Auditory Nerve Fibers. II. Dependence on Spontaneous Activity and Relation to Cochlear Nonlinearity

2008 ◽  
Vol 100 (5) ◽  
pp. 2899-2906 ◽  
Author(s):  
Andrei N. Temchin ◽  
Nola C. Rich ◽  
Mario A. Ruggero
Keyword(s):  
Spontaneous Activity ◽  
Auditory Nerve ◽  
Characteristic Frequency ◽  
Basilar Membrane ◽  
Frequency Tuning ◽  
Nerve Fibers ◽  
Nonmonotonic Dependence ◽  
Tuning Curves ◽  
Auditory Nerve Fibers ◽  
Threshold Tuning

Spontaneous activity and frequency threshold tuning curves were studied in thousands of auditory nerve fibers in chinchilla. The frequency distribution of spontaneous activity rates is strongly bimodal for auditory nerve fibers with characteristic frequency <3 kHz but only mildly bimodal for the entire sample. Spontaneous activity rates and thresholds at the characteristic frequency are inversely related. Auditory-nerve fibers with low spontaneous rate have tuning curves with lower tip-to-tail ratios and more sharply tuned tips than the tuning curves of fibers with high spontaneous rates. It is shown here that this dependence of tuning on spontaneous rates is consistent with a previously unnoticed nonmonotonic dependence on iso-velocity criterion of the frequency tuning of basilar membrane vibrations.

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