The projections of principal cells of the medial nucleus of the trapezoid body in the cat
Article first published online: 9 OCT 2004
Copyright © 1985 Alan R. Liss, Inc.
Journal of Comparative Neurology
Volume 238, Issue 3, pages 249–262, 15 August 1985
How to Cite
Spangler, K. M., Warr, W. B. and Henkel, C. K. (1985), The projections of principal cells of the medial nucleus of the trapezoid body in the cat. J. Comp. Neurol., 238: 249–262. doi: 10.1002/cne.902380302
- Issue published online: 9 OCT 2004
- Article first published online: 9 OCT 2004
- Manuscript Accepted: 4 APR 1985
- superior olive
Previous studies suggest that the principal cells of the medial nucleus of the trapezoid body (MNTB) give rise to the projection from MNTB to the lateral superior olivary nucleus (LSO) of the same side, where they mediate rapid inhibitory effects of contralateral sound stimulation. In the present study, we explored certain morphological features of this connection as well as several other projections of the MNTB by using anterograde and retrograde axonal tracing methods. Following injections of tritiated leucine into MNTB, labeled axons reached LSO by passing ventral to, dorsal to, and through the medial superior olivary nucleus, and gave rise to labeling around the somata and proximal dendrites of LSO fusiform cells. As measured in autoradiograms of 2 μm plastic sections, these axons had a modal diameter of 5–6 μ. Terminal labeling, tentatively attributed to principal cell axons, was also seen in the ventral nucleus of the lateral lemniscus (VNLL) and the dorsomedial and ventromedial periolivary nuclei. HRP injections into the LSO and the VNLL showed that the prinicpal cell projected to both of these nuclei and revealed a topographic arrangement of the projection to the LSO which is consistent with tonotopic maps determined electrophysiologically. Control HRP injections demonstrated that other minor projections of the MNTB arose from minor cell populations in this nucleus. The findings provide a morphological correlate of certain physiological findings and suggest a wider role for the MNTB in the ascending auditory system than previously has been supposed.