Effects of Unilateral Ablation of Anteroventral Cochlear Nucleus on Localization of Sound in Space
The anteroventral cochlear nucleus is the main source of projections to the medial and lateral superior olives (Stotler, 1953; Warr, 1966; Strominger and Strominger, 1971; Jones, 1979), structures which process binaural information (Brugge and Geisler, 1978) and which most likely play a role in the ability of animals to localize sounds in space (Masterton et al., 1967; Casseday and Neff, 1975). The anteroventral cochlear nucleus also projects to the central nucleus of the inferior colliculus, as do the medial and lateral superior olives. In our laboratory, experiments on the tree shrew (Tupaia glis) show that the projections from the anteroventral nucleus converge in the lateral part of the central nucleus of the inferior colliculus with projections from medial and lateral superior olives (Jones, 1979). Thus, the anteroventral cochlear nucleus, the medial and lateral superior olives and the lateral part of the inferior colliculus seem to be part of a single pathway, the function of which may involve sound localization. To test this idea we trained tree shrews (Tupaia glis) to localize sound, and then tested their ability to localize after unilateral lesions in the anteroventral cochlear nucleus. In this report we will give preliminary evidence that such lesions affect localizing behavior in a unique way.
KeywordsAuditory Cortex Inferior Colliculus Cochlear Nucleus Stimulus Location Sound Localization
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