Auditory responses of neurones in the lateral mesencephalic nucleus (inferior colliculus) of the Barbary dove

Abstract

Auditory responses were recorded from 45 single neurons in the lateral mesencephalic nucleus of the dove, confirming the suspected auditory function of this nucleus. Most of the neurons with sustained responses to tones fell into 3 response-categories inhibitory only, excitatory in a central range of frequencies with inhibition in adjacent frequency regions, and predominantly inhibitory with one or more relatively small excitatory regions. Seven of the neurons studied showed only transient responses: these had high thresholds or were restricted to a narrow range of frequencies. Responses to clicks were sometimes obtained, but were variable in different units and in a single unit were often dependent on repetition rate. Many properties of these neurons are similar to those in the cat inferior colliculus. The most notable difference is the existence in the dove of neurons with exclusively or predominantly inhibitory responses.