Recovery from prior stimulation. I: Relationship to spontaneous firing rates of primary auditory neurons

Relkin, Evan M.; Doucet, John R.

doi:10.1016/0378-5955(91)90106-j

Cited by 117 publications

(84 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The CFs of these ANFs ranged from 0.3 to 39.3 kHz, and their spontaneous rates from near zero up to Ͼ100 spikes per second, covering the wide range of spontaneous rates reported in the cat and other mammalian species (Liberman and Kiang, 1978;Relkin and Doucet, 1991;Taberner and Liberman, 2005). Each rate-level function is based on an ANF's responses to generally 50 repetitions of 100 ms tones, presented at up to 20 different SPLs, and an estimate of its spontaneous rate.…”

Section: Databasementioning

confidence: 83%

See 1 more Smart Citation

An Improved Model for the Rate–Level Functions of Auditory-Nerve Fibers

Heil

Neubauer

Irvine³

2011

J. Neurosci.

View full text Add to dashboard Cite

Acoustic information is conveyed to the brain by the spike patterns in auditory-nerve fibers (ANFs). In mammals, each ANF is excited via a single ribbon synapse in a single inner hair cell (IHC), and the spike patterns therefore also provide valuable information about those intriguing synapses. Here we reexamine and model a key property of ANFs, the dependence of their spike rates on the sound pressure level of acoustic stimuli (rate-level functions). We build upon the seminal model of Sachs and Abbas (1974), which provides good fits to experimental data but has limited utility for defining physiological mechanisms. We present an improved, physiologically plausible model according to which the spike rate follows a Hill equation and spontaneous activity and its experimentally observed tight correlation with ANF sensitivity are emergent properties. We apply it to 156 cat ANF rate-level functions using frequencies where the mechanics are linear and find that a single Hill coefficient of 3 can account for the population of functions. We also demonstrate a tight correspondence between ANF rate-level functions and the Ca 2ϩ dependence of exocytosis from IHCs, and derive estimates of the effective intracellular Ca 2ϩ concentrations at the individual active zones of IHCs. We argue that the Hill coefficient might reflect the intrinsic, biochemical Ca 2ϩ cooperativity of the Ca 2ϩ sensor involved in exocytosis from the IHC. The model also links ANF properties with properties of psychophysical absolute thresholds.

show abstract

Section: Databasementioning

confidence: 83%

“…Spike rates below the spontaneous rate can occur after tone offset (Relkin and Doucet, 1991) and during one half-cycle of low-frequency tones (Rose et al, 1967;Palmer and Russell, 1986). For the model to achieve firing rates below the spontaneous rate, the driven rate, R d , would have to be negative.…”

Section: Limitations Of the Rate-additivity Modelmentioning

confidence: 99%

An Improved Model for the Rate–Level Functions of Auditory-Nerve Fibers

Heil

Neubauer

Irvine³

2011

J. Neurosci.

View full text Add to dashboard Cite

show abstract

“…In that case, our data indirectly suggest that the rate of electric adaptation is inversely related to fiber diameter at the excitation site. There is evidence that ANFs with low spontaneous rate (SR) undergo larger upper threshold shifts in response to forward masking and recover from prior stimulation more slowly than do high SR fibers (Relkin and Doucet 1991). However, low SR fibers exhibit smaller degrees of rapid adaptation (Relkin and Doucet 1991;Cooper et al 1993).…”

Section: Fig 13mentioning

confidence: 99%

Changes Across Time in Spike Rate and Spike Amplitude of Auditory Nerve Fibers Stimulated by Electric Pulse Trains

Zhang

Miller

Robinson

et al. 2007

JARO

143

View full text Add to dashboard Cite

We undertook a systematic evaluation of spike rates and spike amplitudes of auditory nerve fiber (ANF) responses to trains of electric current pulses. Measures were obtained from acutely deafened cats to examine time-related changes free from the effects of hair-cell and synaptic adaptation. Such data relate to adaptation that likely occurs in ANFs of cochlear-implant users. A major goal was to determine and compare rate adaptation observed at different pulse rates (primarily 250, 1000, and 5000 pulse/s) and describe them using decaying exponential models similar to those used in acoustic studies. Rate-vs.-time functions were best described by two-exponent models and produced time constants similar to (although slightly greater than) the Brapid^and Bshort-term^components described in acoustic studies. There was little dependence of these time constants on onset spike rate, but pulse-rate effects were noted. Spike amplitude changes followed a time course different from that of rate adaptation consistent with a process related to ANF interspike intervals. The fact that two time constants governed rate adaptation in electrically stimulated and deafened fibers suggests that future computational models of adaptation should not only include hair cell and synapse components, but also components determined by fiber membrane characteristics.

show abstract

“…From each fiber, we obtained between 1 and 18 samples of spontaneous activity, yielding a total of 461 samples, each lasting between 12.5 and 135 s. The mean spontaneous discharge rates (mean SR) of the fibers (averaged across all unpruned samples from a given fiber) ranged from Ͻ0.1 to ϳ100 Hz, covering the wide range of spontaneous rates reported in the cat and other species (Kiang et al, 1965;Walsh et al, 1972;Liberman and Kiang, 1978;Müller and Robertson, 1991;Relkin and Doucet, 1991;Yates, 1991;Gleich and Wilson, 1993;Richter et al, 1995;Köppl and Yates, 1999;Yates et al, 2000;Taberner and Liberman, 2005). The distribution of SRs was bimodal, with one maximum at ϳ1 Hz (low-SR fibers) and the other at ϳ40 -80 Hz (high-SR fibers), in agreement with previous reports for the cat (Kiang et al, 1965;Liberman, 1978;Joris and Yin, 1992).…”

Section: Databasementioning

confidence: 99%

Spontaneous Activity of Auditory-Nerve Fibers: Insights into Stochastic Processes at Ribbon Synapses

Heil¹,

Neubauer²,

Irvine³

et al. 2007

J. Neurosci.

View full text Add to dashboard Cite

In several sensory systems, the conversion of the representation of stimuli from graded membrane potentials into stochastic spike trains is performed by ribbon synapses. In the mammalian auditory system, the spiking characteristics of the vast majority of primary afferent auditory-nerve (AN) fibers are determined primarily by a single ribbon synapse in a single inner hair cell (IHC), and thus provide a unique window into the operation of the synapse. Here, we examine the distributions of interspike intervals (ISIs) of cat AN fibers under conditions when the IHC membrane potential can be considered constant and the processes generating AN fiber activity can be considered stationary, namely in the absence of auditory stimulation. Such spontaneous activity is commonly thought to result from an excitatory Poisson point process modified by the refractory properties of the fiber, but here we show that this cannot be the case. Rather, the ISI distributions are one to two orders of magnitude better and very accurately described as a result of a homogeneous stochastic process of excitation (transmitter release events) in which the distribution of interevent times is a mixture of an exponential and a gamma distribution with shape factor 2, both with the same scale parameter. Whereas the scale parameter varies across fibers, the proportions of exponentially and gamma distributed intervals in the mixture, and the refractory properties, can be considered constant. This suggests that all of the ribbon synapses operate in a similar manner, possibly just at different rates. Our findings also constitute an essential step toward a better understanding of the spike-train representation of time-varying stimuli initiated at this synapse, and thus of the fundamentals of temporal coding in the auditory pathway.

show abstract

Recovery from prior stimulation. I: Relationship to spontaneous firing rates of primary auditory neurons

Cited by 117 publications

References 20 publications

An Improved Model for the Rate–Level Functions of Auditory-Nerve Fibers

An Improved Model for the Rate–Level Functions of Auditory-Nerve Fibers

Changes Across Time in Spike Rate and Spike Amplitude of Auditory Nerve Fibers Stimulated by Electric Pulse Trains

Spontaneous Activity of Auditory-Nerve Fibers: Insights into Stochastic Processes at Ribbon Synapses

Contact Info

Product

Resources

About