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.
KeywordsSpike Train Synaptic Conductance Nucleus Magnocellularis Single Compartment Model Membrane Time Constant
Unable to display preview. Download preview PDF.
- Carr, C.E. and M. Konishi (1990). A circuit for detection of interaural time differences in the brainstem of the barn owl. J. Neurosci. 10:3227–3246.Google Scholar
- MacGregor, R.J. (1987). Neural and Brain Modelling. Academic Press, San Diego.Google Scholar
- Moiseff, A. and M. Konishi (1981). Neuronal and behavioral sensitivity to binaural time differences in the owl. J. Neurosci. 1:40–48.Google Scholar
- Sullivan, W.E. and M. Konishi (1984). Segregation of stimulus phase and intensity coding in the cochlear nucleus of the barn owl. J. Neurosci. 4: 1787–1799.Google Scholar