Bilateral projections to the thalamus from individual neurons in the inferior colliculus.

Title

Bilateral projections to the thalamus from individual neurons in the inferior colliculus.

Creator

Mellott Jeffrey G; Beebe Nichole L; Schofield Brett R

Publisher

The Journal of comparative neurology

Date

2019
2019-04

Description

The medial geniculate body (MG) receives a large input from the ipsilateral inferior colliculus (IC) and a smaller but substantial input from the contralateral IC. Both crossed and uncrossed inputs comprise a large percentage of glutamatergic cells and a smaller percentage of GABAergic cells. We used double labeling with fluorescent retrograde tracers to identify individual IC cells that project bilaterally to the MGs in adult guinea pigs. We also used immunohistochemistry for glutamic acid decarboxylase to distinguish GABAergic from glutamatergic cells that project bilaterally to the MG. We found cells in the IC that contained both retrograde tracers, indicating that they project bilaterally. Across cases, the bilaterally projecting cells constituted up to 37% of the cells that project to the ipsilateral MG and up to 73% of the cells that project to the contralateral MG. GABAergic cells averaged 20% of the bilaterally-projecting population. We conclude that a population of IC cells sends branching axonal projections to innervate the MG bilaterally. Most of the neurons in this population are glutamatergic, with a minority that are GABAergic. A mixed projection, with glutamatergic cells outnumbering GABAergic cells, originates from each of the major IC subdivisions (central nucleus, dorsal cortex, and lateral cortex). The bilaterally projecting cells are likely to serve functions different from the larger unilateral projections, perhaps synchronizing activity on the two sides of the auditory brain.

Subject

collateral; GABA; inferior colliculus; medial geniculate body; RRID:AB2278725; RRID:AB260754; synchronization

Identifier

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

1118-1126

Issue

6

Volume

527

NEOMED College

NEOMED College of Medicine

NEOMED Department

Department of Anatomy & Neurobiology

Citation

Mellott Jeffrey G; Beebe Nichole L; Schofield Brett R, “Bilateral projections to the thalamus from individual neurons in the inferior colliculus.,” NEOMED Bibliography Database, accessed June 25, 2021, https://neomed.omeka.net/items/show/6253.

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