OLIVOCOCHLEAR NEURONAL RESPONSES IN MEDULLA OF CAT

The activity of olivocochlear neurons in the medulla of cat to simple acoustic stimuli has been studied. Using tungsten microelectrodes, efferent neurons have been isloated both in the region of the superior olivary complex and the floor of the fourth ventricle. These neurons respond similarly, in many respects, to olivocochlear neurons located within the internal acoustic meatus. The spontaneous activity of these neurons is low in rate and regular in occurrence which are features that, in general, are distinctly different from auditory afferent neurons. Furthermore, these neurons exhibit changes in their spontaneous rate that may be determined by more central and peripheral influences. An auditory stimulus may cause an increase, a decrease, or no change in the neuron's discharges. Which of these effects is produced depends upon the spontaneous activity of the neuron at the moment of acoustic stimulation. © 1968.