1. Understanding the Nature of Sleep and How it Changes With Age

2. Sleep-Wake Cycle 2-Process Model

3. Normal Sleep-Wake Cycle and SCN

4. The Neurobiology of Sleep

5. Normal Sleep Cycles Young Adults

6. Sleep Fragmentation in a 70-Year-Old Man

7. Actigraphy Data 72-Year-Old Man

8. Sleep Structure

9. Quality of Sleep Declines With Age

10. Age-Related Changes to Sleep

11. Percentage of Sleep Complaints in 9282 Older Adults

12. Persistence of Sleep Complaints in 1050 Older Adults at 2 Years

13. Comorbid Conditions Contribute to Sleep Complaints in Older Adults

14. Sleep Problems and Multiple Medical Conditions

15. Discovery of the Biologic Clock

16. Circadian and Sleep Disturbances in Aging

17. Circadian Rhythms and Aging

18. Circadian Rhythm Age-Related Changes May Disrupt Tonic Orexin Secretion

19. Circadian Rhythm Sleep Disorders Endogenous Misalignment: ASPD

20. Morbidity of Insomnia

21. Sleep Duration and Risk of Falls

22. Falls in Older Adults

23. Nocturia and Sleep Issues

24. Nocturnal Awakening Disrupts Sleep

25. Mediation Analysis of Insomnia and Depression

26. Chronic Insomnia Independently Predicts Cognitive Decline in Older Men

27. The Number of Orexin Neurons Decreases With Age

28. Orexin Levels and Age

29. Plasma Orexin-A Levels Increase in Patients With Insomnia

30. Orexin-A Levels Are Correlated With Alzheimer Disease Biomarkers

31. Higher CSF-Orexin Concentrations in Patients With MCI and Sleep Complaints

32. Circadian and Sleep Dysfunction in Cognitive Impairment and Alzheimer Disease

33. Circadian and Homeostatic Regulation of Sleep

34. Abbreviations

35. Abbreviations (cont)

36. Abbreviations (cont)