TY - JOUR
T1 - Beyond the hippocampus
T2 - Amygdala and memory functioning in older adults
AU - Bookheimer, Tess H.
AU - Ganapathi, Aarthi S.
AU - Iqbal, Fatima
AU - Popa, Emily S.
AU - Mattinson, Jenna
AU - Bramen, Jennifer E.
AU - Bookheimer, Susan Y.
AU - Porter, Verna R.
AU - Kim, Mihae
AU - Glatt, Ryan M.
AU - Bookheimer, Austin W.
AU - Merrill, David A.
AU - Panos, Stella E.
AU - Siddarth, Prabha
N1 - Publisher Copyright:
© 2024 The Authors
PY - 2024/8/5
Y1 - 2024/8/5
N2 - Background: Medial temporal lobe atrophy has been linked to decline in neuropsychological measures of explicit memory function. While the hippocampus has long been identified as a critical structure in learning and memory processes, less is known about contributions of the amygdala to these functions. We sought to investigate the relationship between amygdala volume and memory functioning in a clinical sample of older adults with and without cognitive impairment. Methods: A serial clinical sample of older adults that underwent neuropsychological assessment at an outpatient neurology clinic was selected for retrospective chart review. Patients were included in the study if they completed a comprehensive neuropsychological assessment within six months of a structural magnetic resonance imaging scan. Regional brain volumes were quantified using Neuroreader® software. Associations between bilateral hippocampal and amygdala volumes and memory scores, derived from immediate and delayed recall conditions of a verbal story learning task and a visual design reconstruction task, were examined using mixed-effects general linear models, controlling for total intracranial volume, scanner model, age, sex and education. Partial correlation coefficients, adjusted for these covariates, were calculated to estimate the strength of the association between volumes and memory scores. Results: A total of 68 (39 F, 29 M) participants were included in the analyses, with a mean (SD) adjusted age of 80.1 (6.0) and educational level of 15.9 (2.5) years. Controlling for age, sex, education, and total intracranial volume, greater amygdala volumes were associated with better verbal and visual memory performance, with effect sizes comparable to hippocampal volume. No significant lateralized effects were observed. Partial correlation coefficients ranged from 0.47 to 0.33 (p<.001). Conclusion: These findings contribute to a growing body of knowledge identifying the amygdala as a target for further research in memory functioning. This highlights the importance of considering the broader functioning of the limbic system in which multiple subcortical structures contribute to memory processes and decline in older adults.
AB - Background: Medial temporal lobe atrophy has been linked to decline in neuropsychological measures of explicit memory function. While the hippocampus has long been identified as a critical structure in learning and memory processes, less is known about contributions of the amygdala to these functions. We sought to investigate the relationship between amygdala volume and memory functioning in a clinical sample of older adults with and without cognitive impairment. Methods: A serial clinical sample of older adults that underwent neuropsychological assessment at an outpatient neurology clinic was selected for retrospective chart review. Patients were included in the study if they completed a comprehensive neuropsychological assessment within six months of a structural magnetic resonance imaging scan. Regional brain volumes were quantified using Neuroreader® software. Associations between bilateral hippocampal and amygdala volumes and memory scores, derived from immediate and delayed recall conditions of a verbal story learning task and a visual design reconstruction task, were examined using mixed-effects general linear models, controlling for total intracranial volume, scanner model, age, sex and education. Partial correlation coefficients, adjusted for these covariates, were calculated to estimate the strength of the association between volumes and memory scores. Results: A total of 68 (39 F, 29 M) participants were included in the analyses, with a mean (SD) adjusted age of 80.1 (6.0) and educational level of 15.9 (2.5) years. Controlling for age, sex, education, and total intracranial volume, greater amygdala volumes were associated with better verbal and visual memory performance, with effect sizes comparable to hippocampal volume. No significant lateralized effects were observed. Partial correlation coefficients ranged from 0.47 to 0.33 (p<.001). Conclusion: These findings contribute to a growing body of knowledge identifying the amygdala as a target for further research in memory functioning. This highlights the importance of considering the broader functioning of the limbic system in which multiple subcortical structures contribute to memory processes and decline in older adults.
KW - Amygdala
KW - Hippocampus
KW - Older adults
KW - Verbal memory
KW - Visual memory
UR - http://www.scopus.com/inward/record.url?scp=85196478996&partnerID=8YFLogxK
U2 - 10.1016/j.bbr.2024.115112
DO - 10.1016/j.bbr.2024.115112
M3 - Article
C2 - 38871129
AN - SCOPUS:85196478996
SN - 0166-4328
VL - 471
JO - Behavioural Brain Research
JF - Behavioural Brain Research
M1 - 115112
ER -