Oscillating neurons in the cochlear nucleus: I. Experimental basis of a simulation paradigm

Anatomical and physiological auditory data and pitch measurements are presented including some additional analysis. The data provide the basis for a new computer model of sustained chopper neurons in the ventral cochlear nucleus. New and old evidence indicating a preference for multiples of 0.4 ms in oscillations of chopper neurons in the cochlear nucleus of different species such as man, cats, and Guinea fowls, is summarized. Our hypothesis is that the time constant of 0.4 ms is due to the minimum synaptic delay of chopper neuron connections. Anatomical findings show that chopper neurons are indeed connected and can excite each other; a model of a circular network of neurons that are connected via synapses with a delay of 0.4 ms is thus plausible. Results concerning frequency tuning and dynamical properties of periodicity encoding of chopper neurons are reviewed. It is concluded that chopper neurons receive input both from auditory nerve fibres and onset neurons.