Pathways from auditory cortex to the cochlear nucleus in guinea pigs.

Title

Pathways from auditory cortex to the cochlear nucleus in guinea pigs.

Creator

Schofield Brett R; Coomes Diana L

Publisher

Hearing research

Date

2006
2006-07

Description

The inferior colliculus (IC) and superior olivary complex (SOC) are important sources of descending pathways to the cochlear nucleus. The IC and SOC are also targets of direct projections from the auditory cortex but it is not known if cortical axons contact the cells that project to the cochlear nucleus. Multi-labeling techniques were used to address this question in guinea pigs. A fluorescent anterograde tracer was injected into temporal cortex to label corticofugal axons. Different fluorescent tracers were injected into one or both cochlear nuclei to label olivary and collicular cells. The brain was subsequently processed for fluorescence microscopy and the IC and SOC were examined for apparent contacts between cortical axons and retrogradely labeled cells. The results suggest that cortical axons contact cochlear nucleus-projecting cells in both IC and SOC. In both regions, contacts were more numerous on the side ipsilateral to the injected cortex. In the IC, the contacted cells projected ipsilaterally or contralaterally to the CN. In the SOC, the contacted cells projected ipsilaterally, contralaterally or bilaterally to the CN. We conclude that auditory cortex is in a position to modulate descending pathways from both the IC and SOC to the cochlear nucleus.

Subject

Animals; Auditory Cortex/*anatomy & histology/physiology; Auditory Pathways/anatomy & histology/physiology; Axons/physiology/ultrastructure; Cochlear Nucleus/*anatomy & histology/physiology; Efferent Pathways/*anatomy & histology/physiology; Efferent/physiology; Fluorescence; Fluorescent Dyes; Guinea Pigs; Inferior Colliculi/*anatomy & histology/physiology; Microscopy; Neurons; Olivary Nucleus/*anatomy & histology/physiology

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

81–89

Volume

216-217

Citation

Schofield Brett R; Coomes Diana L, “Pathways from auditory cortex to the cochlear nucleus in guinea pigs.,” NEOMED Bibliography Database, accessed November 30, 2021, https://neomed.omeka.net/items/show/3578.

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