Projections from the dorsal and ventral cochlear nuclei to the medial geniculate body. 2014

Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
Department of Anatomy and Neurobiology, Northeast Ohio Medical University Rootstown, OH, USA ; School of Biomedical Sciences, Kent State University Kent, OH, USA.

Direct projections from the cochlear nucleus (CN) to the medial geniculate body (MG) mediate a high-speed transfer of acoustic information to the auditory thalamus. Anderson etal. (2006) used anterograde tracers to label the projection from the dorsal CN (DCN) to the MG in guinea pigs. We examined this pathway with retrograde tracers. The results confirm a pathway from the DCN, originating primarily from the deep layers. Labeled cells included a few giant cells and a larger number of small cells of unknown type. Many more labeled cells were present in the ventral CN (VCN). These cells, identifiable as multipolar (stellate) or small cells, were found throughout much of the VCN. Most of the labeled cells were located contralateral to the injection site. The CN to MG pathway bypasses the inferior colliculus (IC), where most ascending auditory information is processed. Anderson etal. (2006) hypothesized that CN-MG axons are collaterals of axons that reach the IC. We tested this hypothesis by injecting different fluorescent tracers into the MG and IC and examining the CN for double-labeled cells. After injections on the same side of the brain, double-labeled cells were found in the contralateral VCN and DCN. Most double-labeled cells were in the VCN, where they accounted for up to 37% of the cells labeled by the MG injection. We conclude that projections from the CN to the MG originate from the VCN and, less so, from the DCN. A significant proportion of the cells send a collateral projection to the IC. Presumably, the collateral projections send the same information to both the MG and the IC. The results suggest that T-stellate cells of the VCN are a major source of direct projections to the auditory thalamus.

UI MeSH Term Description Entries

Related Publications

Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
January 2012, The Journal of comparative neurology,
Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
August 1997, The Journal of comparative neurology,
Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
December 1974, Brain research,
Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
January 1974, Experimental brain research,
Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
July 1996, Proceedings of the National Academy of Sciences of the United States of America,
Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
May 1969, Brain research,
Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
May 1986, The Journal of comparative neurology,
Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
January 1987, Brain research,
Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
June 1994, The Journal of comparative neurology,
Brett R Schofield, and Susan D Motts, and Jeffrey G Mellott, and Nichole L Foster
October 2000, The Journal of comparative neurology,
Copied contents to your clipboard!