1. Prepared by Grant McLaren, Department of Psychology, Edinboro University of Pennsylvania FOUNDATIONS OF BEHAVIORAL NEUROSCIENCE 9 TH EDITION This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network, preparation of any derivative work, including the extraction, in whole or in part, of any images, any rental, lease or lending of the program Copyright © 2014 Pearson Education, Inc. All Rights Reserved

2. Chapter 8 Sleep and Biological Rhythms Copyright © 2014 Pearson Education, Inc. All Rights Reserved

3. A Physiological and Behavioral Description of Sleep Disorders of Sleep Insomnia Narcolepsy REM Sleep Behavior Disorder Problems Associated with Slow-Wave Sleep

4. Copyright © 2014 Pearson Education, Inc. All Rights Reserved Why Do We Sleep? Functions of Slow-Wave Sleep Functions of REM Sleep Sleep and Learning Physiological Mechanisms of Sleep and Waking Chemical Control of Sleep Neural Control of Arousal Neural Control of Slow-Wave Sleep Neural Control of REM Sleep

5. Copyright © 2014 Pearson Education, Inc. All Rights Reserved Biological Clocks Circadian Rhythms and Zeitgebers The Suprachiasmatic Nucleus Changes in Circadian Rhythms: Shift Work and Jet lag

6. Sleep and Biological Rhythms Learning Objectives 1. Describe the course of a night's sleep: its stages and their characteristics. 2. Discuss insomnia, sleeping medications, and sleep apnea. 3. Discuss narcolepsy and sleep disorders associated with REM sleep and slow-wave sleep. 4. Review the hypothesis that sleep serves as a period of restoration by discussing the effects of sleep deprivation, exercise, and mental activity. 5. Discuss research on the effects of REM sleep and slow-wave sleep on learning. 6. Evaluate evidence that the onset and amount of sleep is chemically controlled, and describe the neural control of arousal. 7. Discuss the neural control of slow-wave sleep, including the sleep/waking flip-flop and the role of orexinergic neurons. 8. Discuss the neural control of REM sleep, including the REM sleep flip-flop. 9. Describe circadian rhythms and discuss research on the neural and physiological bases of these rhythms. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

7. Physiological and Behavioral Description of Sleep electromyogram (EMG) (my oh gram) An electrical potential recorded from an electrode placed on or in a muscle. electro-oculogram (EOG) (ah kew loh gram) An electrical potential from the eyes, recorded by means of electrodes placed on the skin around them; detects eye movements. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

9. Physiological and Behavioral Description of Sleep alpha activity Smooth electrical activity of 8–12 Hz recorded from the brain; generally associated with a state of relaxation. beta activity Irregular electrical activity of 13–30 Hz recorded from the brain; generally associated with a state of arousal. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

11. Physiological and Behavioral Description of Sleep theta activity EEG activity of 3.5–7.5 Hz that occurs intermittently during early stages of slow-wave sleep and REM sleep. delta activity Regular, synchronous electrical activity of less than 4 Hz recorded from the brain; occurs during the deepest stages of slow-wave sleep. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

12. Physiological and Behavioral Description of Sleep slow-wave sleep Non-REM sleep, characterized by synchronized EEG activity during its deeper stages. rapid eye movement (REM) sleep A period of desynchronized EEG activity during sleep, at which time dreaming, rapid eye movements, and muscular paralysis occur; also called paradoxical sleep. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

16. Disorders of Sleep Copyright © 2014 Pearson Education, Inc. All Rights Reserved Insomnia Because we spend about one-third of our lives sleeping, sleep disorders can have a significant impact on our quality of life. They can also affect the way we feel while we are awake. Insomnia is a problem that is said to affect approximately 25 percent of the population occasionally and 9 percent regularly. Insomnia is characterized as difficulty falling asleep after going to bed or after awakening during the night. But a significant problem in identifying insomnia is the unreliability of self-reports.

17. Disorders of Sleep Patients with this disorder, called sleep apnea, fall asleep and then cease to breathe. (Apnos is Greek for “without breathing.”) Nearly all people, especially people who snore, have occasional episodes of sleep apnea, but not to the extent that it interferes with sleep. Copyright © 2014 Pearson Education, Inc. All Rights Reserved Insomnia sleep apnea (app nee a) Cessation of breathing while sleeping.

18. Disorders of Sleep Copyright © 2014 Pearson Education, Inc. All Rights Reserved Narcolepsy narcolepsy (nahr ko lep see) A sleep disorder characterized by periods of irresistible sleep, attacks of cataplexy, sleep paralysis, and hypnagogic hallucinations. sleep attack A symptom of narcolepsy; an irresistible urge to sleep during the day, after which the person awakens feeling refreshed.

19. Disorders of Sleep Copyright © 2014 Pearson Education, Inc. All Rights Reserved Narcolepsy cataplexy (kat a plex ee) A symptom of narcolepsy; complete paralysis that occurs during waking. sleep paralysis A symptom of narcolepsy; paralysis occurring just before a person falls asleep. hypnagogic hallucination (hip na gah jik) A symptom of narcolepsy; vivid dreams that occur just before a person falls asleep; accompanied by sleep paralysis.

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21. Disorders of Sleep Copyright © 2014 Pearson Education, Inc. All Rights Reserved Narcolepsy orexin A peptide, also known as hypocretin, produced by neurons whose cell bodies are located in the hypothalamus; their destruction causes narcolepsy.

22. Disorders of Sleep Copyright © 2014 Pearson Education, Inc. All Rights Reserved Narcolepsy In humans, narcolepsy appears to be caused by a hereditary autoimmune disorder. Most patients with narcolepsy are born with orexinergic neurons, but during adolescence the immune system attacks these neurons, and the symptoms of narcolepsy begin.

23. Disorders of Sleep Copyright © 2014 Pearson Education, Inc. All Rights Reserved Narcolepsy The symptoms of narcolepsy can be treated with drugs. Sleep attacks can be diminished by stimulants such a methylphenidate (Ritalin), a catecholamine agonist (Vgontzas and Kales, 1999). The REM sleep phenomena (cataplexy, sleep paralysis, and hypnagogic hallucinations) have traditionally been treated with antidepressant drugs, which facilitate both serotonergic and noradrenergic activity.

24. Disorders of Sleep Copyright © 2014 Pearson Education, Inc. All Rights Reserved REM Sleep Behavior Disorder REM sleep behavior disorder A neurological disorder in which the person does not become paralyzed during REM sleep and thus acts out dreams. Like narcolepsy, REM sleep behavior disorder appears to be a neurodegenerative disorder with at least some genetic component (Schenck et al., 1993). It is often associated with better-known neurodegenerative disorders such as Parkinson’s disease (Boeve et al., 2007).

25. Disorders of Sleep Copyright © 2014 Pearson Education, Inc. All Rights Reserved Problems with Slow-Wave Sleep sleep-related eating disorder A disorder in which the person leaves his or her bed and seeks out and eats food while sleepwalking, usually without a memory for the episode the next day.

26. Why Do We Sleep? Although the issue is not yet settled, most researchers believe that the primary function of slow-wave sleep is to permit the brain to rest. In addition, slow-wave sleep and REM sleep promote different types of learning, and REM sleep appears to promote brain development. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

27. Why Do We Sleep? Functions of Slow-Wave Sleep Sleep is a universal phenomenon among vertebrates. As far as we know, all mammals and birds sleep (Durie, 1981). Reptiles also sleep, and fish and amphibians enter periods of quiescence that probably can be called sleep. Sleep appears to be essential to survival in some capacity. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

29. Why Do We Sleep? Effects of Sleep Deprivation The results of sleep deprivation studies suggest that the restorative effects of sleep are more important for the brain than for the rest of the body. Sleep deprivation studies with human subjects have provided little evidence that sleep is needed to keep the body functioning normally. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

30. Why Do We Sleep? Effects of Sleep Deprivation fatal familial insomnia A fatal inherited disorder characterized by progressive insomnia. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

31. Why Do We Sleep? Effects of Exercise on Slow-Wave Sleep The relationship between sleep and exercise is not very compelling. For example, Ryback and Lewis (1971) found no changes in slow- wave or REM sleep of healthy subjects who spent six weeks resting in bed. If sleep repairs wear and tear, we would expect these people to sleep less. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

32. Why Do We Sleep? Functions of REM Sleep REM sleep is a time of intense physiological activity. The eyes dart about rapidly, the heart rate shows sudden accelerations and decelerations, breathing becomes irregular, and the brain becomes more active. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

33. Why Do We Sleep? Functions of REM Sleep It would be unreasonable to expect that REM sleep has the same functions as slow-wave sleep. Researchers have long been struck by the fact that the highest proportion of REM sleep is seen during the most active phase of brain development. Perhaps, then, REM sleep plays a role in this process (Siegel, 2005). Copyright © 2014 Pearson Education, Inc. All Rights Reserved

34. Why Do We Sleep? Functions of REM Sleep rebound phenomenon The increased frequency or intensity of a phenomenon after it has been temporarily suppressed; for example, the increase in REM sleep seen after a period of REM sleep deprivation. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

35. Why Do We Sleep? Sleep and Learning Research with both humans and laboratory animals indicates that sleep does more than allow the brain to rest: It also aids in the consolidation of long-term memories (Marshall and Born, 2007). In fact, slow-wave sleep and REM sleep play different roles in memory consolidation. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

38. Physiological Mechanism of Sleep and Waking Chemical Control of Sleep adenosine (a den oh seen) A neuromodulator that is released by neurons engaging in high levels of metabolic activity, may play a primary role in the initiation of sleep. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

39. Physiological Mechanism of Sleep and Waking Neural Control of Arousal Circuits of neurons that secrete at least five different neurotransmitters play a role in some aspect of an animal’s level of alertness and wakefulness—what is commonly called arousal: acetylcholine, norepinephrine, serotonin, histamine, and orexin (Wada et al., 1991; McCormick, 1992; Marrocco, Witte, and Davidson, 1994; Hungs and Mignot, 2001). Copyright © 2014 Pearson Education, Inc. All Rights Reserved

40. Physiological Mechanism of Sleep and Waking Neural Control of Arousal Acetylcholine One of the most important neurotransmitters involved in arousal— especially of the cerebral cortex—is acetylcholine. Two groups of ACh neurons, one in the dorsal pons and one located in the basal forebrain, produce activation and cortical desynchrony when they are stimulated (Jones, 1990; Steriade, 1996). Copyright © 2014 Pearson Education, Inc. All Rights Reserved

42. Physiological Mechanism of Sleep and Waking Neural Control of Arousal Norepinephrine Investigators have long known that catecholamine agonists such as amphetamine produce arousal and sleeplessness. These effects appear to be mediated primarily by the noradrenergic system of the locus coeruleus, located in the dorsal pons. locus coeruleus (sa roo lee us) A dark-colored group of noradrenergic cell bodies located in the pons near the rostral end of the floor of the fourth ventricle; involved in arousal and vigilance. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

44. Physiological Mechanism of Sleep and Waking Neural Control of Arousal Serotonin A third neurotransmitter, serotonin (5-HT) also appears to play a role in activating behavior. Almost all of the brain’s serotonergic neurons are found in the raphe nuclei, which are located in the medullary and pontine regions of the reticular formation. raphe nuclei (ruh fay) A group of nuclei located in the reticular formation of the medulla, pons, and midbrain, situated along the midline; contain serotonergic neurons. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

46. Physiological Mechanism of Sleep and Waking Neural Control of Arousal Histamine The fourth neurotransmitter implicated in the control of wakefulness and arousal is histamine, a compound synthesized from histidine, an amino acid. tuberomammillary nucleus (TMN) A nucleus in the ventral posterior hypothalamus, just rostral to the mammillary bodies; contains histaminergic neurons involved in cortical activation and behavioral arousal. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

47. Physiological Mechanism of Sleep and Waking Neural Control of Arousal Orexin As we saw earlier, narcolepsy is most often treated with modafinil, a drug that suppresses the drowsiness associated with this disorder. Ishizuka, Murotani, and Yamatodani (2010) found that the modafinil produces its alerting effects by stimulating the release of orexin in the TMN, which activates the histaminergic neurons located there. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

49. Physiological Mechanism of Sleep and Waking Neural Control of Slow-Wave Sleep Sleep is controlled by three factors: homeostatic, allostatic, and circadian. If we go without sleep for a long time, we will eventually become sleepy, and once we sleep, we will be likely to sleep longer than usual and make up at least some of our sleep debt. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

50. Physiological Mechanism of Sleep and Waking Neural Control of Slow-Wave Sleep ventrolateral preoptic area (vlPOA) A group of GABAergic neurons in the preoptic area whose activity suppresses alertness and behavioral arousal and promotes sleep. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

54. Physiological Mechanism of Sleep and Waking Neural Control of REM Sleep As we shall see, REM sleep is controlled by a flip-flop similar to the one that controls cycles of sleep and waking. The sleep/waking flip-flop determines when we wake and when we sleep, and once we fall asleep, the REM flip-flop controls our cycles of REM sleep and slow-wave sleep. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

55. Physiological Mechanism of Sleep and Waking The REM Flip-Flop As we saw earlier in this chapter, acetylcholinergic neurons play an important role in cerebral activation during alert wakefulness. Researchers have also found that they are involved in the neocortical activation that accompanies REM sleep. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

57. Physiological Mechanism of Sleep and Waking The REM Flip-Flop sublaterodorsal nucleus (SLD) A region of the dorsal pons, just ventral to the locus coeruleus, that forms the REM-ON portion of the REM sleep flip-flop. ventrolateral periaqueductal gray matter (vlPAG) A region of the dorsal midbrain that forms the REM-OFF portion of the REM sleep flip-flop. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

60. Physiological Mechanism of Sleep and Waking The REM Flip-Flop A functional imaging study by Schwartz et al. (2008) found that when people with cataplexy watched humorous sequences of photographs, the hypothalamus was activated less, and the amygdala was activated more, than the same structures in control subjects. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

61. Physiological Mechanism of Sleep and Waking The REM Flip-Flop The investigators suggest that the loss of hypocretinergic neurons removed an inhibitory influence of the hypothalamus on the amygdala. The increased amygdala activity could account at least in part for the increased activity of REM-on neurons that occurs even during waking in people with cataplexy. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

63. Physiological Mechanism of Sleep and Waking The REM Flip-Flop The investigators suggest that the loss of hypocretinergic neurons removed an inhibitory influence of the hypothalamus on the amygdala. The increased amygdala activity could account at least in part for the increased activity of REM-on neurons that occurs even during waking in people with cataplexy. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

65. Biological Clocks Circadian Rhythms and Zeitgebers circadian rhythm (sur kay dee un or sur ka dee un) A daily rhythmical change in behavior or physiological process. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

67. Biological Clocks Circadian Rhythms and Zeitgebers zeitgeber (tsite gay ber) A stimulus (usually the light of dawn) that resets the biological clock that is responsible for circadian rhythms. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

68. Biological Clocks The Suprachiasmatic Nucleus suprachiasmatic nucleus (SCN) (soo pra ky az mat ik) A nucleus situated atop the optic chiasm. It contains a biological clock that is responsible for organizing many of the body’s circadian rhythms. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

69. Biological Clocks Anatomy and Connections Figure 8.22 shows the suprachiasmatic nuclei in a cross section through the hypothalamus of a rat; they appear as two clusters of dark-staining neurons at the base of the brain, just above the optic chiasm. (See Figure 8.22.) The suprachiasmatic nuclei of the rat consist of approximately 8,600 small neurons, tightly packed into a volume of 0.036 mm 3 (Moore, Speh, and Leak, 2002). Copyright © 2014 Pearson Education, Inc. All Rights Reserved

71. Biological Clocks Anatomy and Connections melanopsin (mell a nop sin) A photopigment present in ganglion cells in the retina whose axons transmit information to the SCN, the thalamus, and the olivary pretectal nuclei. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

73. Biological Clocks Anatomy and Connections Evidence indicates that SCN controls cycles of sleep and waking by two means: direct neural connections and the secretion of chemicals that affect the activity of neurons in other regions of the brain. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

75. Biological Clocks The Nature of the Clock Several studies have demonstrated daily activity rhythms in the SCN, which indicates that the circadian clock is located there. A study by Schwartz and Gainer (1977) nicely demonstrated day– night fluctuations in the activity of the SCN. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

77. Biological Clocks The Nature of the Clock What causes SCN neurons to “tick”? For many years investigators have believed that circadian rhythms were produced by the production of a protein that, when it reached a certain level in the cell, inhibited its own production. As a result, the levels of the protein would begin to decline, which would remove the inhibition, starting the production cycle again. (See Figure 8.26.) Copyright © 2014 Pearson Education, Inc. All Rights Reserved

79. Biological Clocks The Nature of the Clock advanced sleep phase syndrome A 4-hour advance in rhythms of sleep and temperature cycles, apparently caused by a mutation of a gene (per2) involved in the rhythmicity of neurons of the SCN. delayed sleep phase syndrome A 4-hour delay in rhythms of sleep and temperature cycles, possibly caused by a mutation of a gene (per3) involved in the rhythmicity of neurons of the SCN. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

80. Biological Clocks Changes in Circadian Rhythms: Shift Work and Jet Lag pineal gland (py nee ul) A gland attached to the dorsal tectum; produces melatonin and plays a role in circadian and seasonal rhythms. melatonin (mell a tone in) A hormone secreted during the night by the pineal body; plays a role in circadian and seasonal rhythms. Copyright © 2014 Pearson Education, Inc. All Rights Reserved