Effects of sleep on the glymphatic system and human brain network affecting memory in older adults
Poster No:
903
Submission Type:
Abstract Submission
Authors:
Junji Ma1, Ji-Tseng Fang2, Shwu-Hua Lee2, Tatia Lee1
Institutions:
1University of Hong Kong, Hong Kong, China, 2Chang Gung University, Taoyuan, China
First Author:
Co-Author(s):
Introduction:
Sleep complaints are common in older adults. Long-term sleep problems could hamper cognitive functions, especially memory, and increase the risk of neurocognitive disorders (e.g., Alzheimer's disease) in older adults (Mander et al., 2017). Understanding the neurophysiological mechanism underpinning sleep-related memory declines in older adults is crucial for developing effective treatments and promoting healthy aging. Here, we focused on glymphatic system, a metabolic waste clearance pathway in human brain that plays a crucial role in determining brain health (Iliff et al., 2012), and adopted multimodal MRI techniques to explore the interplay between sleep quality, glymphatic functioning, and multimodal brain networks in older adults and explore how this relationship contribute to memory function.
Methods:
Resting-sate functional MRI (R-fMRI) and diffusion MRI (dMRI) data were acquired from 72 older adults in Taiwan. To assess sleep quality, Pittsburgh Sleep Quality Index (PSQI) and Polysomnographic recording of these participants were also collected. Memory performance was assessed by Everyday Cognition Questionnaire (ECog). Using the dMRI data, we calculated a DTI-ALPS index (Taoka et al., 2017) as a proxy of the glymphatic functioning. Then we constructed functional connectivity network (FCN) and structural connectivity network (SCN) for each participant based on the R-fMRI and dMRI data respectively. Furthermore, the coupling between both networks (SC-FC coupling), including coupling of whole brain connectivity and rich-club connectivity (van den Heuvel & Sporns, 2011), was calculated.
First, we performed correlation analysis to examine the association between DTI-ALPS and sleep quality measures or multimodal brain networks. Second, we conducted a mediation analysis to test whether DTI-ALPS can mediate the relationship between sleep quality and human brain network. Finally, we conducted a moderated mediation analysis to test whether the brain-glymphatic relationship can contribute to memory function and how it interacts with sleep quality.
First, we performed correlation analysis to examine the association between DTI-ALPS and sleep quality measures or multimodal brain networks. Second, we conducted a mediation analysis to test whether DTI-ALPS can mediate the relationship between sleep quality and human brain network. Finally, we conducted a moderated mediation analysis to test whether the brain-glymphatic relationship can contribute to memory function and how it interacts with sleep quality.
Results:
Correlation results revealed that DTI-ALPS was negatively correlated with sleep quality measures (i.e., PSQI and apnea-hypopnea index) (r ≤ -0.314, p ≤ -0.011). Regarding human brain networks, DTI-ALPS was associated with the strength of both functional connectivity (FC) and structural connectivity (SC) involving the middle temporal gyrus, parahippocampal gyrus, and insular (Fig. 1AB). Besides the connectivity of specific networks, we also found a negative association between the DTI-ALPS and SC-FC coupling of rich-club connections (Fig. 1CD). Furthermore, we found that DTI-ALPS positively mediated the association between sleep quality and rich-club SC-FC coupling (PSQI: 95% CI = [0.004, 0.233], AHI: 95% CI = [0.013, 0.213]). The rich-club SC-FC coupling further mediated the association between DTI-ALPS and the memory score of ECog in good sleepers (PSQI ≤ 5) but not in poor sleepers (Fig. 2).
·Figure 1
·Figure 2
Conclusions:
By using the DTI-ALPS, our study was able to non-invasively evaluate glymphatic functioning and examine its relationship with sleep and the human brain network. Our findings provide novel insights that the glymphatic system is protective of neural interaction in the human brain, which can also be the missing link between glymphatic functioning and the pathologies of neurodegenerative diseases (e.g., Alzheimer's disease). With regard to the effect of sleep quality, results reveal that poor sleep quality in older adults may gradually impair normal brain function (i.e., SC-FC coupling) by deactivating the restorative glymphatic system. The disrupted brain-glymphatic relationship underlies the memory decline in poor sleepers.
Learning and Memory:
Long-Term Memory (Episodic and Semantic)
Lifespan Development:
Aging 1
Modeling and Analysis Methods:
Connectivity (eg. functional, effective, structural) 2
Diffusion MRI Modeling and Analysis
Neuroanatomy, Physiology, Metabolism and Neurotransmission:
Anatomy and Functional Systems
Keywords:
Aging
MRI
Sleep
Other - Glymphatic System
1|2Indicates the priority used for review
Abstract Information
By submitting your proposal, you grant permission for the Organization for Human Brain Mapping (OHBM) to distribute your work in any format, including video, audio print and electronic text through OHBM OnDemand, social media channels, the OHBM website, or other electronic publications and media.
The Open Science Special Interest Group (OSSIG) is introducing a reproducibility challenge for OHBM 2025. This new initiative aims to enhance the reproducibility of scientific results and foster collaborations between labs. Teams will consist of a “source” party and a “reproducing” party, and will be evaluated on the success of their replication, the openness of the source work, and additional deliverables. Click here for more information. Propose your OHBM abstract(s) as source work for future OHBM meetings by selecting one of the following options:
Please indicate below if your study was a "resting state" or "task-activation” study.
Healthy subjects only or patients (note that patient studies may also involve healthy subjects):
Was this research conducted in the United States?
Were any human subjects research approved by the relevant Institutional Review Board or ethics panel? NOTE: Any human subjects studies without IRB approval will be automatically rejected.
Were any animal research approved by the relevant IACUC or other animal research panel? NOTE: Any animal studies without IACUC approval will be automatically rejected.
Please indicate which methods were used in your research:
For human MRI, what field strength scanner do you use?
Which processing packages did you use for your study?
Provide references using APA citation style.
Mander, B. A., Winer, J. R., & Walker, M. P. (2017). Sleep and human aging. Neuron, 94(1), 19-36.
Taoka, T., Masutani, Y., Kawai, H., Nakane, T., Matsuoka, K., Yasuno, F., ... & Naganawa, S. (2017). Evaluation of glymphatic system activity with the diffusion MR technique: diffusion tensor image analysis along the perivascular space (DTI-ALPS) in Alzheimer’s disease cases. Japanese journal of radiology, 35, 172-178.
Van Den Heuvel, M. P., & Sporns, O. (2011). Rich-club organization of the human connectome. Journal of Neuroscience, 31(44), 15775-15786.