Glycine immunoreactivity of multipolar neurons in the ventral cochlear nucleus which project to the dorsal cochlear nucleus
Article first published online: 10 MAY 1999
Copyright © 1999 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 408, Issue 4, pages 515–531, 14 June 1999
How to Cite
Doucet, J. R., Ross, A. T., Gillespie, M. B. and Ryugo, D. K. (1999), Glycine immunoreactivity of multipolar neurons in the ventral cochlear nucleus which project to the dorsal cochlear nucleus. J. Comp. Neurol., 408: 515–531. doi: 10.1002/(SICI)1096-9861(19990614)408:4<515::AID-CNE6>3.0.CO;2-O
- Issue published online: 10 MAY 1999
- Article first published online: 10 MAY 1999
- Manuscript Accepted: 18 JAN 1999
- Manuscript Revised: 13 JAN 1999
- Manuscript Received: 6 AUG 1997
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health Research. Grant Numbers: R01 DC00232, P60 DC00979
- auditory system;
- biotinylated dextran amine;
Certain distinct populations of neurons in the dorsal cochlear nucleus are inhibited by a neural source that is responsive to a wide range of acoustic frequencies. In this study, we examined the glycine immunoreactivity of two types of ventral cochlear nucleus neurons (planar and radiate) in the rat which project to the dorsal cochlear nucleus (DCN) and thus, might be responsible for this inhibition. Previously, we proposed that planar neurons provided a tonotopic and narrowly tuned input to the DCN, whereas radiate neurons provided a broadly tuned input and thus, were strong candidates as the source of broadband inhibition (Doucet and Ryugo  J. Comp. Neurol. 385:245–264). We tested this idea by combining retrograde labeling and glycine immunohistochemical protocols. Planar and radiate neurons were first retrogradely labeled by injecting biotinylated dextran amine into a restricted region of the dorsal cochlear nucleus. The labeled cells were visualized using streptavidin conjugated to indocarbocyanine (Cy3), a fluorescent marker. Sections that contained planar or radiate neurons were then processed for glycine immunocytochemistry using diaminobenzidine as the chromogen. Immunostaining of planar neurons was light, comparable to that of excitatory neurons (pyramidal neurons in the DCN), whereas immunostaining of radiate neurons was dark, comparable to that of glycinergic neurons (cartwheel cells in the dorsal cochlear nucleus and principal cells in the medial nucleus of the trapezoid body). These results are consistent with the hypothesis that radiate neurons in the ventral cochlear nucleus subserve the wideband inhibition observed in the dorsal cochlear nucleus. J. Comp. Neurol. 408:515–531, 1999. © 1999 Wiley-Liss, Inc.