Pattern responses of low-frequency inferior colliculus neurons

Abstract

Most inferior colliculus neurons exhibit temporal discharge pattern changes as a function of one or more stimulus parameters. These pattern changes, in a general sense, usually take the form of shifts from an onset to a pause or continuous response as a function of small changes in the frequency, intensity, or interaural phase angle of the stimulus. In cases where stimulus changes do not alter the over-all discharge pattern, changes occur in latency and distribution of the onset discharge or the total number of discharges. The variety of stimuli to which each neuron is differentially responsive suggests that characteristics of the discharge pattern, not simply “place,” may mediate information transmission at higher levels of the auditory pathway. Since the timing of arrival of disparate neural inputs is critical to transsynaptic processing, it is possible that discharge pattern, as well as total number of discharges, determines the influence a specific neuron has upon those to which it projects. Thus, each discharge pattern may permit the neuron to maximally affect the responses of some higher level neurons while minimally affecting the responses of others.