Sleep & Attention

1. Sleep & Attention June 23, 2011

2. Sleep Architechture

3. Why Do We Sleep? • Who knows?!? It’s not entirely clear. • However, we do know that all organisms, from fruit flies to humans, show some form of sleep-like behavior. • Sleep is ESSENTIAL • Sleep deprived humans can become paranoid and have hallucinations. • Sleep deprived rats can die after 2-3 weeks. • We do have some ideas…

4. Function Brain or body restoration, or both Replenishment of cerebral glycogen Tissue synthesis and cell mitosis Protein synthesis Growth hormone release Thermo regulation Energy conservation Regulation of noradrenergic activity Memory consolidation and information processing Brain development Cell maturation Development of oculomotor control Programming of genetically determined behaviors Neural stimulation Proposed functions of sleep NREM sleep + + + + + + + REM sleep + + + + + + + + + From Lecture at Emory University , 2006

5. What is Sleep?

6. Awake State • Alpha Waves • Smooth, synchronous activity from 8-12 Hz • Relaxation • Beta Waves • Irregular, desynchronous activity from 13-30 Hz • Arousal & Wakefulness http://pn.bmj.com/content/10/5/300.full

7. Stage 1 & 2 Sleep • Theta Waves • 3.5-7.5 Hz EEG activity • Early slow-wave sleep and REM sleep • Stage 2 sleep is also characterized by sleep spindles and K complexes (short bursts of waves that may help person fall into deeper sleep by decreasing sensitivity to outer stimuli) http://pn.bmj.com/content/10/5/300.full

8. Stage 3 & 4 Sleep • Delta Activity • High-amplitude (less than 3.5 Hz) • Stage 3 consists of approx 20-50% delta activity • Stage 4 consists of more than 50% delta activity http://pn.bmj.com/content/10/5/300.full

9. REM Sleep • Desynchronized EEG movement accompanied by Rapid Eye Movement • 15-30 Hz waves • Also characterized by inability to move your muscles (paradoxical sleep) • This is the stage when dreams occur. http://healthy-ojas.com/sleep/sleep-stages.html

10. Sleep Progression and Cycle http://pn.bmj.com/content/10/5/300.full

11. Astronaut Sleep Activity

12. Neurobiology of Sleep

13. Sleep in the Brain http://www.hms.harvard.edu/hmni/On_The_Brain/Volume04/Number4/Sleep.html

14. Ventrolateral Preoptic Area • Releases GABA to inhibit wake-promoting regions of the brain and thereby promote sleep • Destruction of the VLPA causes insomnia in rats • Electrical stimulation causes sleepiness From Lecture at Emory University , 2006

15. Sleep Promotion • Sleep promoting regions in the VLPA release inhibitory GABA signals to • Acetylcholine neurons in basal forebrain • Histaminergic neurons in the tuberomammillary nucleus • Hypocretin neurons • Noreprinephrine neurons in the Locus Ceruleus • Serotonin in the Dorsal Raphe • Inhibition of these regions decreases wakefulness and increases sleepiness

16. REM Sleep Promotion • During REM sleep, the ACh and hypocretin neurons remain active. • Projections from the Medial Pontine Reticular Formation activate ACh neurons in the cerebral cortex to keep them active.

17. Thalamus,Cortex Models of sleep-waking regulation Waking NE Hcrt HA 5-HT ACh TM LC DR ACh Hcrt From Lecture at Emory University , 2006

18. Waking NREM sleep Thalamus,Cortex Thalamus,Cortex NE Hcrt HA 5-HT ACh TM LC DR ACh GABA Hcrt POA Models of sleep-waking regulation From Lecture at Emory University , 2006

19. Waking REM sleep Thalamus,Cortex Thalamus,Cortex NE Hcrt HA 5-HT ACh TM LC DR ACh GABA Hcrt POA+PAG Models of sleep-waking regulation ACh Hcrt From Lecture at Emory University , 2006

20. Dream Journal Analysis

21. Nova Science NOW http://www.mptv.org/podcasts/show/?p_id=21

23. Sleepiness Log Analysis

24. Discussion • Did you find any rhythms or patterns in your sleep log? • What do these rhythms mean? http://mrbarlow.files.wordpress.com/2010/08/normalsleep.gif

25. Circadian Rhythms • Daily 24-hour rhythms in several chemicals, like melatonin, help control our sleep/wake cycles. • Melatonin is secreted by the pineal gland. http://www.endotext.org/neuroendo/neuroendo15/neuroendo15.htm

26. What Regulates Circadian Rhythms? • The Suprachiasmatic Nucleus (SCN) is our primary biological clock that organizes these rhythms. • It does this through its projections to the midbrain and hypothalamic nuclei. http://people.usd.edu/~cliff/Courses/Behavioral%20Neuroscience/Biorhythm/BRfigs/BRAfferent%20SCN%20figures.html

27. The Michael Siffre Story

28. Sleep Difficulties

29. Sleep Disorder Quiz • Do you snore loudly and/or heavily while asleep? • Are you excessively sleepy or do you lack energy in the daytime? • Do you have trouble with concentration or memory loss? • Do you fall asleep while driving, in meetings, while reading a book, or while watching television? • Do you have occasional morning headaches? • Do you sleepwalk, have nightmares, or have night terrors? • Do you suffer from depression or mood changes? • Do you have trouble going to sleep or staying asleep? • Have you experienced recent weight gain or high blood pressure? • Have you been told you hold your breath when you sleep?

30. Narcolepsy • Characterized by suddenly falling asleep at an inappropriate time • Cataplexy, a common symptom, involves complete paralysis during a narcoleptic attack. • Likely caused by activation of REM sleep promoting brain areas at inappropriate times • Mutations in the gene responsible for producing hypocretin are also involved • Successfully treated by stimulants that increase serotonergic and noradrenergic activity

32. Night Terrors • Terrifying period of screaming, trembling, and racing heart • Usually does not remember what caused the night terror • Associated with slow-wave sleep • Most common in children, these are usually out-grown with age and do not require treatment

33. Restless Leg Syndrome • Insatiable urge to move ones legs in order to escape a tingling feeling or an “itch you can’t scratch” • Can also occur to arms, torso, etc • Worsens while relaxing and is relieved by movement or activity • Dopamine and iron deficiency have been implicated

34. Sleep Apnea • Temporary cessation of breathing during sleep • Results in daytime sleepiness and fatigue • May occur when the muscle paralysis of REM sleep extends into the throat muscles • Treatment often includes a CPAP (continuous positive airway pressure) machine to help with breathing during sleep http://apnea-and-snoring.com/?p=29

36. REM without Atonia • What happens if a person in REM sleep DOESN’T have muscle paralysis? • Motor cortex and subcortical motor systems remain active, and without the atonia induced by REM, a person will be able to wake up and act out their dreams. Morrison, A. R., L. D. Sanford, et al. (1995). "Stimulus-elicited behavior in rapid eye movement sleep without atonia." Behavioral neuroscience109(5): 972-979.

37. Sample Case • “I was a halfback playing football, and after the quarterback reeived the ball from the center he lateraled it sideways to me and I’m supposed to go around end and cut back over tack and—this is very vivid—as I cut back over tackle there is this big 280-pound tackle waiting, so I, according to football rules, was to give him my shoulder and bounce him out of the way…”

38. Sample Case, Cont’d • “…When I came to, I was standing in front of our dresser and I had [gotten up out of bed and run and] knocked lamps, mirrors, and everything off the dresser, hit my head against the wall, and my knee against the dresser.” Schenk et al, 1986, p. 294

39. Why Am I So Sleepy or Hyper?

40. Design a Public Service Announcement

41. Neurobiology of Attention & Arousal http://www.doctorsecrets.com/your-kids/attention-deficit-disorder-symptoms.html

42. You Are Getting Very Sleepy… • Remember from this morning: Sleep occurs when the VLPA is activated and then inhibits: • Acetylcholine neurons in basal forebrain • Histaminergic neurons in the tuberomammillary nucleus • Hypocretin neurons • Noreprinephrine neurons in the Locus Ceruleus • Serotonin in the Dorsal Raphe • So what do you think might happen when you need to wake up?

43. Rise And Shine! • Stimulation of the Brain Stem Reticular Formation leads to arousal and a wake state. • The reticular formation then follows 2 pathways: • Dorsal: Projects through the thalamus to the cerebral cortex • Ventral: Projects through the lateral hypothalamus, basal ganglia, and basal forebrain regions to the cortex & hippocampus

44. NBM DR MS LDT LC DBB PPT Hcrt TM Anatomy of the arousal systems Histamine, serotonin, norepinephrine, acetylcholine, hypocretin From Lecture at Emory University , 2006

45. Reticular Formation and Beyond • Activation of the Reticular Formation results in release of: • Histamine from the tuberomammillary nucleus (TMN) • Norepinephrine in the locus ceruleus (LC) • Serotonin from the dorsal raphe (DR) • Hypocretin from the Lateral hypothalamic area (LHA) • Together, this helps you become awake!

46. NREM sleep Waking Arousal Systems - Histamine - c-fos activity tuberomammillary nucleus (TMN) From Lecture at Emory University , 2006

47. Arousal Systems - Norepinephrine - Waking locus coeruleus (LC) c-fos activity From Lecture at Emory University , 2006

48. Arousal Systems - Serotonin - dorsal raphe (DR) From Lecture at Emory University , 2006

49. Arousal Systems - Hypocretin (orexin) - Waking NREM sleep Lateral hypothalamic area (LHA) c-fos activity From Lecture at Emory University , 2006

50. Thalamus,Cortex Models of sleep-waking regulation Waking NE Hcrt HA 5-HT ACh TM LC DR ACh Hcrt From Lecture at Emory University , 2006