A resonance model of high frequency binaural phase sensitivity in the barn owl’s auditory brainstem
The auditory system of the barn owl (tyto alba) contains neurons sensitive to the phase of sounds of remarkably high frequency up to 9 kHz. Nucleus Laminaris represents phase differences as part of the computation of stimulus azimuth. The high frequency of the stimulus and the high level of noise in the input spike trains make the response properties of laminaris neurons hard to explain. We use simulations and semi-numerical analysis to show that the cellular and synaptic time constants must be unreasonably fast in order for ordinary biophysical mechanisms to reproduce the observed behavior. Several people have suggested that a resonance mechanism may exist in laminaris neurons to amplify the signal. We present a simple neuronal resonance model that can deal with realistic input.
KeywordsClay Azimuth Alba Chol Stim
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