world alzheimer's day 21 september 2023

Highlighting the links between Alzheimer’s disease and sleep for World Alzheimer’s Day

21st of September is World Alzheimer’s Day.

Today we aim to bring awareness of this neurodegenerative disease, which is predicted to affect over 70 million people worldwide by 2030, and its links to sleep.

Alzheimer’s disease (AD) is the most common type of dementia among the elderly causing progressive and irreversible deterioration of memory, thinking, and behaviour.

Alzheimer’s disease is characterized by two main pathological hallmarks: Aβ plaques and neurofibrillary tangles. These protein deposits accumulate in the brain, leading to the gradual deterioration of nerve cells and their connections. Typical symptoms of AD include decline in cognitive function, such as memory loss, confusion, and difficulty with daily tasks. As the disease advances, individuals struggle to recognize loved ones and lose the ability to communicate or care for themselves. Currently, there is no cure for AD, but several basic research laboratories are studying this disease by using different animal models.

For the past decades, several publications have shed light on the close connection between AD and sleep. In AD patients, harmful proteins like Aβ peptide and phosphorylated tau accumulate in different areas of the brain, including regions that control sleep and circadian rhythms. Sleep plays a crucial role in clearing these proteins from the brain. Conversely, the presence of Aβ plaques in the brain can disrupt sleep, and more than 80% of AD patients show disturbed circadian rhythms and difficulties falling or staying asleep.

ESRS-associated laboratories in Italy, the Netherlands, Belgium, Serbia, and Greece are conducting animal research on the links between AD and sleep. Animal models utilizing worms, mice, zebrafish, drosophila, and non-human primates can help us investigate how the harmful proteins that accumulate in AD affect sleep. Researchers can manipulate the animals’ sleep patterns to mimic sleep disturbances and observe how sleep disruption impacts the accumulation of AD-related proteins. Animal models also allow scientists to explore the underlying biological mechanisms linking sleep disturbances and AD pathology, ultimately advancing our understanding and potential treatments for the disease.

An infographic highlighting the key research findings using different animal models to investigate the links between AD and sleep has been developed by Isabela Valentim whose work is focused on neurodegenerative disorders and sleep and Maria Hrozanova from the ESRS DCC. You can find all the papers referenced in the infographic and links to the ESRS labs doing this work below.

Infographic "Alzheimer's Disease and Sleep"

alzheimers disease and sleep infographic_portrait

Download the “Alzheimer’s Disease and Sleep” Infographic in PDF format:

Article and infographic written and design by:
Dr. Isabela Santos Valentim

Dr. Isabela Santos Valentim

Postdoctoral researcher at the Leibniz Institute on Aging – Fritz Lipmann Institute (FLI) and a member of the ESRS Digital and Communication Committee.

Dr. Maria Hrozanova

Dr. Maria Hrozanova

Postdoctoral fellow at the Department of Public Health and Nursing, Norwegian University of Science and Technology (NTNU), Norway, and a member of the ESRS Digital and Communication Committee.

Infographic References

  1. Colwell (2021). Defining circadian disruption in neurodegenerative disorders. J Clin Invest.
  2. Fifel and Videnovic (2021). Circadian and Sleep Dysfunctions in Neurodegenerative Disorders-An Update. Front Neurosci.
  3. Melentijevic et al. (2017). C. elegans neurons jettison protein aggregates and mitochondria under neurotoxic stress. Nature.
  4. Chandra et al. (2023). Sleep is required to consolidate odor memory and remodel olfactory synapses. Cell.
  5. Whittaker et al. (2023). Circadian modulation by time-restricted feeding rescues brain pathology and improves memory in mouse models of Alzheimer’s disease. Cell Metab.
  6. Xie et al. (2013). Sleep drives metabolite clearance from the adult brain. Science.
  7. Özcan et al. (2020). Sleep is bi-directionally modified by amyloid beta oligomers. Elife.
  8. Dissel (2020). Drosophila as a Model to Study the Relationship Between Sleep, Plasticity, and Memory. Front Physiol.
  9. Kaldun et al. (2021). Dopamine, sleep, and neuronal excitability modulate amyloid-β-mediated forgetting in Drosophila. PLoS Biol.
  10. Zhdanova et al. (2011). Aging of intrinsic circadian rhythms and sleep in a diurnal nonhuman primate, Macaca mulatta. J Biol Rhythms.

Recent publications from ESRS members

  1. Dressle et al. (2023). On the relationship between EEG spectral analysis and pre-sleep cognitive arousal in insomnia disorder: towards an integrated model of cognitive and cortical arousal. J Sleep Res.
  2. Valli et al. (2023). Subjective experiences during dexmedetomidine- or propofol-induced unresponsiveness and non-rapid eye movement sleep in healthy male subjects. Br J Anaesth.
  3. Teräs et al. (2023). The association of previous night’ssleep duration with cognitive function among older adults: a pooled analysis ofthree Finnish cohorts. Eur J Ageing.
  4. Evanger et al. (2023). Laterschool start time is associated with longer school day sleep duration and lesssocial jetlag among Norwegian high school students: Results from a large-scale,cross-sectional study. J Sleep Res.
  5. Aellen et al. (2023). isentangling the complex landscape of sleep-wake disorders with data-drivenphenotyping: A study of the Bernese center. Eur J Neurol.
  6. Hietakoste et al. (2023). Acute cardiorespiratory couplingimpairment in worsening sleep apnea-related intermittent hypoxemia. IEEE TransBiomed Eng.
  7. Lu et al. (2023). Comparative study of the SleepImage ring device and polysomnographyfor diagnosing obstructive sleep apnea. Biomed Eng Lett.
Are you an ESRS member and have just published an article?  
Want your research to be featured in a Sleep Science Friday publication? 
Or, if just have a good idea for an article / saw something that sparked your interest,