TY - JOUR
T1 - Structural and functional characterization of the locus coeruleus in young and late middle-aged individuals
AU - Berger, Alexandre
AU - Koshmanova, Ekaterina
AU - Beckers, Elise
AU - Sharifpour, Roya
AU - Paparella, Ilenia
AU - Campbell, Islay
AU - Mortazavi, Nasrin
AU - Balda, Fermin
AU - Yi, Yeo-Jin
AU - Lamalle, Laurent
AU - Dricot, Laurence
AU - Phillips, Christophe
AU - Jacobs, Heidi I L
AU - Talwar, Puneet
AU - El Tahry, Riëm
AU - Sherif, Siya
AU - Vandewalle, Gilles
PY - 2023/6/21
Y1 - 2023/6/21
N2 - INTRODUCTION: The brainstem locus coeruleus (LC) influences a broad range of brain processes, including cognition. The so-called LC contrast is an accepted marker of the integrity of the LC that consists of a local hyperintensity on specific Magnetic Resonance Imaging (MRI) structural images. The small size of the LC has, however, rendered its functional characterization difficult in humans, including in aging. A full characterization of the structural and functional characteristics of the LC in healthy young and late middle-aged individuals is needed to determine the potential roles of the LC in different medical conditions. Here, we wanted to determine whether the activation of the LC in a mismatch negativity task changes in aging and whether the LC functional response was associated to the LC contrast. METHODS: We used Ultra-High Field (UHF) 7-Tesla functional MRI (fMRI) to record brain response during an auditory oddball task in 53 healthy volunteers, including 34 younger (age: 22.15y ± 3.27; 29 women) and 19 late middle-aged (age: 61.05y ± 5.3; 14 women) individuals. RESULTS: Whole-brain analyses confirmed brain responses in the typical cortical and subcortical regions previously associated with mismatch negativity. When focusing on the brainstem, we found a significant response in the rostral part of the LC probability mask generated based on individual LC images. Although bilateral, the activation was more extensive in the left LC. Individual LC activity was not significantly different between young and late middle-aged individuals. Importantly, while the LC contrast was higher in older individuals, the functional response of the LC was not significantly associated with its contrast. DISCUSSION: These findings may suggest that the age-related alterations of the LC structural integrity may not be related to changes in its functional response. The results further suggest that LC responses may remain stable in healthy individuals aged 20 to 70.
AB - INTRODUCTION: The brainstem locus coeruleus (LC) influences a broad range of brain processes, including cognition. The so-called LC contrast is an accepted marker of the integrity of the LC that consists of a local hyperintensity on specific Magnetic Resonance Imaging (MRI) structural images. The small size of the LC has, however, rendered its functional characterization difficult in humans, including in aging. A full characterization of the structural and functional characteristics of the LC in healthy young and late middle-aged individuals is needed to determine the potential roles of the LC in different medical conditions. Here, we wanted to determine whether the activation of the LC in a mismatch negativity task changes in aging and whether the LC functional response was associated to the LC contrast. METHODS: We used Ultra-High Field (UHF) 7-Tesla functional MRI (fMRI) to record brain response during an auditory oddball task in 53 healthy volunteers, including 34 younger (age: 22.15y ± 3.27; 29 women) and 19 late middle-aged (age: 61.05y ± 5.3; 14 women) individuals. RESULTS: Whole-brain analyses confirmed brain responses in the typical cortical and subcortical regions previously associated with mismatch negativity. When focusing on the brainstem, we found a significant response in the rostral part of the LC probability mask generated based on individual LC images. Although bilateral, the activation was more extensive in the left LC. Individual LC activity was not significantly different between young and late middle-aged individuals. Importantly, while the LC contrast was higher in older individuals, the functional response of the LC was not significantly associated with its contrast. DISCUSSION: These findings may suggest that the age-related alterations of the LC structural integrity may not be related to changes in its functional response. The results further suggest that LC responses may remain stable in healthy individuals aged 20 to 70.
KW - Ultra-High Field (7 Tesla)
KW - aging
KW - locus coeruleus
KW - neuromelanin
KW - oddball paradigm
U2 - 10.3389/fnimg.2023.1207844
DO - 10.3389/fnimg.2023.1207844
M3 - Article
SN - 2813-1193
VL - 2
JO - Frontiers in neuroimaging
JF - Frontiers in neuroimaging
M1 - 1207844
ER -