A model of the hair cell-primary fiber complex

Abstract

The proposed model consists of a chain of three energy reservoirs through which energy from an infinite supply is fed to a modulator which in turn drives a firing mechanism. The modulator consists of a variable permeability p that depends on instantaneous basilar displacement a through: p = (a - AO)2 for a greater than AO, and p = O for a less than or equal to AO, where AO is a constant. The firing mechanism consists of a Poisson generator (process) whose average output rate is proportional to energy flow through the modulator, and a classical "leaky integrator" neuronal model driven by the Poisson generator. The model, containing three fixed and eight free parameters, was examined with respect to statistical properties of spontaneous activity, relation between overall firing rate and level of stimulation, various adaptation and recovery phenomena within time ranges from a few milliseconds to several seconds, period histograms for one- and two-tone (phase locked) stimulation, suppression of responses to one tone by subthreshold levels of another (phase locked) tone, and neural masking. Model behavior in general was satisfactory. Deficiencies in single-cycle histograms at medium and high levels, and insufficient onset peaking in PST histograms, were attributed to the malfunctioning of one particular segment of the model, and a possible remedy was suggested.

Simulation of auditory–neural transduction: Further studies

“…In recent years, a number of increasingly sophisticated computational models of this process have been presented that aim to explain the particular nonlinearities that occur at the junction between the inner hair cells and individual auditory-nerve fibers, the point of neuromechanical transduction (Siebert, 1965;Weiss, 1966;Nilsson, 1975;Schroeder and Hall, 1974;Oono and Sujaku, 1975;Eggermont, 1973;Geisler et al, 1979;Brachman, 1980;Ross, 1982;Schwid and Geisler, 1982;Smith and Brachman, 1982;Westerman, 1985;Westerman and Smith, 1986;Cooke, 1986;Meddis, 1986).…”

A phenomenological model of the synapse between the inner hair cell and auditory nerve: Long-term adaptation with power-law dynamics

“…Although the mechanism that gives rise to synaptic adaptation is not completely understood, it could be caused either by the depletion of neurotransmitter from a readily releasable presynaptic pool of neurotransmitter ͑Moser and Beutner, 2000; Schnee et al, 2005;Goutman and Glowatzki, 2007͒ or by the desensitization of post-synaptic receptors ͑Raman et al, 1994͒. Modeling the adaptation in the IHC-AN synapse has been a focus of extensive research over the last several decades. Early attempts employed a single-reservoir system with loss and replenishment of transmitter quanta ͑Schroeder and Hall, 1974;Sujaku, 1974, 1975͒, and later models added extra reservoirs ͑or sites͒ or more complex principles of transmitter flow control ͑Furukawa and Matsuura, 1978;Furukawa et al, 1982;Ross, 1982Ross, , 1996Schwid and Geisler, 1982;Smith and Brachman, 1982;Cooke, 1986;Meddis, 1986Meddis, , 1988Westerman and Smith, 1988͒. In general, the transmitter in these models lies in reservoirs or sites close to the presynaptic membrane and diffuses between reservoirs within the cell and out of the cell to the synaptic cleft.…”

Sensitivity of auditory-nerve fibers to changes in intensity: A dichotomy between decrements and increments

“…Adaptation produces an emphasis on the response to changes in intensity and may play an important role in the encoding of dynamic stimuli such as speech {e.g., Delgutte, 1980). The present results are part of an ongoing effort to describe the quantitative properties of adaptation in order to gain a better understanding of its underlying mechanisms and to allow proper incorporation of adaptation into models of the auditory periphery {e.g., Ross, 1982;Schwid and Geisler, 1982;Smith and Brachman, 1982).…”