Evidence map›Paper›PMID 33578260›Full record

ArticleHearing research2021

Effects of brainstem lesions on amino acid levels in the rat cochlear nucleus.

Donald A Godfrey, William B Farms, Sharon Polensek, Jon D Dunn, Timothy G Godfrey

Open access · greenAbstract read
In one paragraph

Article in Hearing research, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
0.2field-weighted citation impact, top 57% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed, 3 citations in OpenAlex.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 3 institutions in 1 country.

Donald A GodfreyDepartment of Neurology and Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, United States. Electronic address: Donald.godfrey@utoledo.edu.
William B FarmsDepartment of Neurology and Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, United States.
Sharon PolensekChief of Geriatrics, Extended Care and Rehabilitation, Atlanta VA Healthcare System, and Assistant Professor of Neurology, Emory University, Atlanta, GA (Formerly Sharon Shannon-Hartman).
Jon D DunnDepartment of Anatomy, Oral Roberts University, Tulsa, OK, United States.
Timothy G GodfreyDepartment of Neurology and Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, United States.
University of Toledo · USEmory University · USOral Roberts University · US

Funding

MICROCHEMISTRY OF THE COCHLEAR NUCLEUSR01DC000172 · NIDCD · UNIVERSITY OF TOLEDO HEALTH SCI CAMPUS · PI GODFREY, DONALD A. · 1989 to 1998
–
NIDCD NIH HHS R01 DC000172
6 · The paper itself

Abstract

There is evidence for glutamate, γ-amino butyric acid (GABA), and glycine as neurotransmitters of centrifugal pathways to the cochlear nucleus, but the quantitative extent of their contributions to amino acid neurotransmission in cochlear nucleus regions has not been known. We used microdissection of freeze-dried tissue sections of rat cochlear nucleus, with mapping of sample locations, combined with a high performance liquid chromatography (HPLC) assay, to measure amino acid levels in cochlear nucleus subregions of rats with unilateral lesions of centrifugal pathways to the cochlear nucleus. In rats with lesions transecting all or almost all pathways to the cochlear nucleus from brain stem regions, GABA, aspartate, and glutamate levels were reduced, compared to contralateral values, in almost all ipsilateral cochlear nucleus regions. The largest reductions, in dorsal (DCN), anteroventral (AVCN), and posteroventral (PVCN) cochlear nucleus regions, approached 50% for GABA, 40% for aspartate, and 30% for glutamate. In contrast, glutamine and taurine levels were typically higher in lesioned-side cochlear nucleus regions than contralaterally. Effects on glycine levels were mixed but usually included increased lesioned-side values compared to contralateral, probably reflecting a balance between increases during protein breakdown and decreases of free glycine in transected pathways. More limited lesions transecting just dorsal pathways showed much less effect on amino acid levels. Lesion of the ipsilateral trapezoid body connection plus ipsilateral superior olivary nuclei resulted in decreases of GABA, aspartate, and glutamate levels especially in ventral cochlear nucleus regions. No clear contralateral effects of this lesion could be shown. The results most strongly support centrifugal GABAergic pathways to the cochlear nucleus, providing almost half of GABAergic neurotransmission in most regions. Our results support and extend previously published measurements of lesion effects on GABA uptake and release in cochlear nucleus subdivisions.

Indexed as

Cochlear NucleusAmino AcidsAnimalsAspartic Acidgamma-Aminobutyric AcidGlutamic AcidGlycineOlivary NucleusRatsAmino AcidsAspartic Acidgamma-Aminobutyric AcidGlutamic AcidGlycineAspartateAuditoryGABAGlutamateHearingTaurine

Identifiers

PMID33578260
PMCPMC7959039
OpenAlexW3127055855

What OpenQuestion holds

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Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.