Characteristics Of Information Processing Of Bushy Cell In Auditory Midbrain

Bushy cell is one of the major constituent cell types in the ventral cochlear nucleus, which relays the majority of information from auditory nerve to the superior olivary complex, where the initial calculations for azimuthal sound localization are performed. Hence, the characteristics of information processing of bushy cell make a strong impact on sound localization. Our research on this problem may provide some cues for the neural mechanisms of encoding binaural localization in auditory brainstem.First of all, the influence of temperature on neuronal excitability is studied by numerical simulations on the spiking threshold characteristics of bushy cells periodically stimulated by synaptic currents. The results reveal that there is a cut-off frequency for the spiking of bushy cell in a specific temperature environment, corresponding to the existence of a critical temperature for the neuron to respond with real spikes to the synaptic stimulus of a given frequency, due to the finiteness of spike width. An optimal temperature range for neuronal spiking is also found for a specific stimulus frequency, and the temperature range span decreases with increasing stimulus frequency. These findings imply that there is a physiological temperature range which is beneficial for the information processing in auditory system. Besides that, we also consider the influence of kinetic and stochastic properties of ion channels on information processing of bushy cell. The results demonstrate that the stochastic factor of ion channels may be beneficial for information processing in auditory system, the mechanism of which need further discuss.On the other hand, we study on the response characteristics of bushy cell, which is composed of a dendrite, a soma and an axon, with compartmental model of bushy cell. The results reveal that the dimension of dendrite and axon of bushy cell effects on the timing of information processing of bushy cell; the function of soma is important for the response characteristics of bushy cell, which makes a decision about whether information can be transmitted to the end of axon; and the role of axon is to optimize the firing waveform of bushy cell, which is of great benefit to the further information processing.These conclusions enable us to understand the mechanism of information processing of bushy cell clearly, and provide some important cues for the mechanism of sound localization.