Age differences in diffusivity in the locus coeruleus and its ascending noradrenergic tract

• Published in: NeuroImage (Orlando, Fla.) Vol. 251; p. 119022
• Main Authors: Porat, Shai, Sibilia, Francesca, Yoon, Josephine, Shi, Yonggang, Dahl, Martin J., Werkle-Bergner, Markus, Düzel, Sandra, Bodammer, Nils, Lindenberger, Ulman, Kühn, Simone, Mather, Mara
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2022; Elsevier Limited; Elsevier
• Subjects: Age differences; Aged; Aging; Alzheimer's disease; Anisotropy; Arousal; Brain stem; Confidence intervals; Datasets; Diffusion; Diffusion Magnetic Resonance Imaging; Eigenvalues; Humans; Locus coeruleus; Locus Coeruleus - diagnostic imaging; Magnetic resonance imaging; Neuroimaging; Noradrenergic bundle; Norepinephrine; Older people; Registration; Substantia alba; Values; White Matter - diagnostic imaging; Neuroimaging; Aging; Noradrenergic bundle; Diffusion; Locus coeruleus
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2022.119022

•Fractional anisotropy in the locus coeruleus was lower in younger adults.•Fractional anisotropy in the noradrenergic bundle was higher in younger adults.•We replicated our fractional anisotropy findings in two separate datasets. The noradrenergic locus coeruleus (LC) is a small brainstem nucleus that promotes arousal and attention. Recent studies have examined the microstructural properties of the LC using diffusion-weighted magnetic resonance imaging and found unexpected age-related differences in fractional anisotropy - a measure of white matter integrity. Here, we used two datasets (Berlin Aging Study-II, N = 301, the Leipzig Study for Mind-Body-Emotion Interactions, N = 220), to replicate published findings and expand them by investigating diffusivity in the LC's ascending noradrenergic bundle. In younger adults, LC fractional anisotropy was significantly lower, compared to older adults. However, in the LC's ascending noradrenergic bundle, we observed significantly higher fractional anisotropy in younger adults, relative to older adults. These findings indicate that diffusivity in the LC versus the ascending noradrenergic bundle are both susceptible to structural changes in aging that have opposing effects on fractional anisotropy.