Evidence map›Paper›PMID 41033048›Full record

ArticleNeurobiology of aging2026

Microstructural changes in locus coeruleus-cortical projections in aged bonnet macaques are independent of myelin loss.

Kelsey E McDermott, Laurel Dieckhaus, Courtney Comrie, Victor Sandrin, Elizabeth B Hutchinson, Carol A Barnes

Abstract read
In one paragraph

Article in Neurobiology of aging, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
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

1 citing paper in PubMed.

  1. Article
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

6 authors.

Kelsey E McDermottEvelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, United States.
Laurel DieckhausDepartment of Biomedical Engineering, University of Arizona, Tucson AZ 85721, United States.
Courtney ComrieDepartment of Biomedical Engineering, University of Arizona, Tucson AZ 85721, United States.
Victor SandrinDepartment of Neuroscience, University of Arizona, Tucson AZ 85721, United States.
Elizabeth B HutchinsonDepartment of Biomedical Engineering, University of Arizona, Tucson AZ 85721, United States.
Carol A BarnesEvelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, United States; Department of Neuroscience, University of Arizona, Tucson AZ 85721, United States; Departments of Psychology and Neurology, University of Arizona, Tucson, AZ 85721, United States. Electronic address: carol@nsma.arizona.edu.

Funding

NEUROBEHAVIORAL RELATIONS IN SENESCENT HIPPOCAMPUSR01AG003376 · NIA · UNIVERSITY OF COLORADO AT BOULDER · PI BARNES, CAROL A. · 1985 to 2025
$16.4M
Bruker Biospec 7T Small Animal MRI UpgradeS10OD025016 · OD · UNIVERSITY OF ARIZONA · PI TROUARD, THEODORE P · 2018 to 2018
$600k
Neurobehavioral Relations in Senescent HippocampusR56AG003376 · NIA · UNIVERSITY OF ARIZONA · PI BARNES, CAROL A. · 2009 to 2009
$383k
NIA NIH HHS R01 AG003376NIA NIH HHS R56 AG003376NIH HHS S10 OD025016
6 · The paper itself

Abstract

The locus coeruleus (LC) is a brainstem nucleus best known for being the primary site of noradrenaline production for the forebrain and is involved in the modulation and optimization of behavioral performance. The LC has many targets throughout the cortex, and ascending projections from the LC join the central tegmental tract (CTT), a well-defined white matter brainstem tract in the pons that terminates in the thalamus. Evidence indicates that the LC is one of the first brain regions to show pathological burden in Alzheimer's disease (AD), and AD patients exhibit structural alterations in the LC and its ascending projections. The extent to which changes occur in the LC and its projections in normal aging, however, is less clear. Analysis of LC-forebrain tractography has historically been difficult due to the small size of the LC as well as the abundance of crossing fibers in the brainstem. Ex vivo magnetic resonance imaging (MRI) allows us to overcome some of these setbacks, as longer scan times can be used to generate higher resolution images than is possible in live subjects. Here, we utilize a cohort of bonnet macaques, an excellent model of normative aging, and analyze the microstructure of the LC and its projections that join the CTT with respect to age. We have been able to overcome issues associated with LC tractography and have found a negative association with age and diffusivity.

Indexed as

AgingCerebral CortexLocus CoeruleusMyelin SheathAlzheimer DiseaseAnimalsFemaleMagnetic Resonance ImagingMaleNeural PathwaysAgingDiffusionImagingRelaxometryTractography

Identifiers

PMID41033048
PMCPMC12522120

What OpenQuestion holds

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Registered trials

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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.