1. Sleep and Biological Rhythms
Sarah Chollar
11/2/09

2. What is Sleep? Sleep as a behavior American Heritage Dictionary
Sleep: A natural periodic state of rest for the mind and body, in which the eyes usually close and consciousness is completely or partially lost, so that there is a decrease in bodily movement and responsiveness to external stimuli. During sleep the brain in humans and other mammals undergoes a characteristic cycle of brain-wave activity that includes intervals of dreaming.

3. Why Sleep? Functions of Slow-Wave Sleep Functions of REM Sleep
Essential for Survival
Reduction of Free Radicals
Functions of REM Sleep
Promote Brain Development
Facilitate Learning
Sleep and Learning
Consolidation of long-term memories
REM: consolidation of nondeclarative memory
Slow-wave: consolidation of declarative memory

4. Species specific hours of sleep per day, large differences found between species.
What types of factors contribute to this difference?
Horses hours
Bats hours

5. REM Sleep and Development

6. Studying Sleep Invasive Techniques Noninvasive Techniques
Electroencephalography (EEG) is a noninvasive tool used to study phenomena related to sleep
Activity of a population of neurons recorded through electrodes on scalp
Electromyogram (EMG)
Electro-oculogram (EOG)

7. Patterns of Activity Alpha: smooth, medium frequency 8-12 Hz
Beta: irregular, low amplitude Hz
Theta: Hz activity
Delta: activity less than 4 Hz
Sleep spindles: short bursts of Hz
K complexes: sudden sharp waveforms

8. Stages of Sleep Awake: Alpha and beta, desynchronous
Stage 1: Theta, more synchronous
Stage 2: Irregular with periods of theta activity, sleep spindles, and K complexes
Stage 3: High amplitude delta (20-50%)
Stage 4: More than 50% delta
Stages 3 and 4 considered to be slow wave sleep (SWS)

9. Stages of Sleep

10. Stages of Sleep

11. Sleep and Memory Nap Studies (Mednick et al., 2003)
Slow wave sleep (SWS)
Consolidation of declarative memory
REM sleep
Consolidation of nondeclarative memory

12. Physiological Mechanisms
Chemical control
Adenosine
Neural control of arousal
Acetylcholine
Norepinephrine
Serotonin
Histamine
Orexin
Neural control of slow-wave sleep
Ventrolateral Preoptic Area (vlPOA)
Neural control of REM sleep
Sublaterodorsal Nucleus (SLD)
Ventrolateral Periaqueductal Gray Matter (vlPAG)

13. Brain Structures for Arousal and Sleep
Pineal Gland
Ventrolateral Preoptic Area (vlPOA)
Suprachiasmatic Nucleus (SCN)
Optic Chiasm
Hypothalamus

14. Anatomical Structures Related to Sleep

15. Neurotransmitter Systems
Norepinephrine
Acetylcholine (Ach)
Histamine
GABA
Serotonin

16. Sleep and Arousal: The Balance
Activity in areas involved in arousal will inhibit areas involved in sleep
Activity in areas that promote sleep will inhibit areas involved in arousal

18. Biological Clocks Circadian Rhythms and Zeitgebers
Circadian Rhythms – daily rhythmical change in behavior or physiological process.
Zeitgebers – stimuli that resets the biological clock responsible for circadian rhythms.
The Suprachiasmatic Nucleus
A hypothalamic nucleus containing the biological clock for many of the body’s circadian rhythms.
Melanopsin – photopigment in retinal ganglion cells that project to the SCN.

20. Daily Changes in Body Temperature

21. Circadian rhythm of body temperature

22. Genetic Control of Sleep and Arousal

23. Sleep Disorders Insomnia Sleep Apnea Narcolepsy
REM Sleep Behavior Disorder
SWS Problems
Nocturnal Enuresis – bedwetting.
Somnambulism – sleepwalking.
Pavor Nocturnus – night terrors.
Sleep-Related Eating Disorder – eating during sleepwalking, often without recollection.
Ambien?

24. Orexin and Arousal
Orexin activates brain stem and forebrain arousal systems
Promotes wakefulness
Narcolepsy problems with orexin producing neurons and receptor B

25. Ambien www.ambiencr.com
AMBIEN CR is indicated to help you fall asleep and/or stay asleep. AMBIEN is indicated for short-term treatment to help you fall asleep.
IMPORTANT SAFETY INFORMATION
AMBIEN and AMBIEN CR are treatment options you and your doctor can consider along with lifestyle changes. When taking either of them, don’t drive or operate machinery. Plan to devote 7 to 8 hours to sleep before being active. Sleepwalking, and eating or driving while not fully awake, with memory loss for the event, as well as abnormal behaviors such as being more outgoing or aggressive than normal, confusion, agitation, and hallucinations may occur. Don’t take it with alcohol as it may increase these behaviors. In patients with depression, worsening of depression, including risk of suicide may occur. If you experience any of these behaviors contact your doctor immediately. Allergic reactions such as shortness of breath, swelling of your tongue or throat, may occur and in rare cases may be fatal. If you have an allergic reaction while using AMBIEN or AMBIEN CR, contact your doctor immediately. Side effects of AMBIEN CR may include next-day drowsiness, dizziness and headache. There is a low occurrence of side effects associated with the short-term use of AMBIEN. The most commonly observed side effects in controlled clinical trials were drowsiness, dizziness, and diarrhea. AMBIEN is taken for 7 to 10 days –or longer as advised by your provider. AMBIEN CR can be taken as long as your doctor recommends. AMBIEN and AMBIEN CR have some risk of dependency. They are non- narcotic

26. Melatonin Pineal Gland
produces melatonin and plays a role in circadian and seasonal rhythms.
Melatonin: hormone secreted during the night by the pineal gland, plays a role in circadian and seasonal rhythms.
Can affect sensitivity of SCN neurons to zeitgebers
Connections from the SCN to the PVN

27. Dreaming Activation-synthesis hypothesis Clinico-Anatomical hypothesis
Contemporary Research
Crosses many disciplines: psychoanalysis, sociology, neuroscience, psychology
Content analysis
Historical Perspectives
Freud
Dream interpretation

28. PGO Activity