copyright © 2008 pearson allyn & bacon inc.1 chapter 8 sleep and biological rhythms this...

Copyright © 2008 Pearson Allyn & Bacon Inc.1

Chapter 8

Sleep and Biological Rhythms

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•Chapter 8 Outline

•A Physiological and Behavioral Description of Sleep

•Disorders of Sleep

•Why Do We Sleep

•Physiological Mechanisms of Sleep and Waking

•Biological Clocks


• A physiological and behavioral description of sleep

• EEG –gross patterns of brain waves involving _____________. Used to define ____________.

• Electromyogram (EMG)• An electrical potential recorded from an electrode

placed on a _________.

• Electro-oculogram (EOG)• An electrical potential from the eyes, recorded by

means of electrodes placed on the skin around them; detects eye movements.

EEG

Measures gross activity of large numbers of neurons.

High-amplitude waves (stage 4) indicate that more neurons are firing in a _________________.

Sleep cycle lasts about _____________.



• Wakefulness

• ______________ activity• A smooth electrical activity of 8–12 Hz recorded from

the brain; generally associated with a state of __________________________.

• __________ activity• Irregular electrical activity of 13–30 Hz recorded from

the brain; generally associated with a state of _________.



• ____________ activity• EEG activity of 3.5-7.5 Hz that occurs intermittently

during early stages of _____________________.• Stage of transition from ______________________.

• ___________ activity• Regular, synchronous electrical activity of less than

4 Hz recorded from the brain; occurs during the _______________________________.



• _________sleep• A period of desynchronized EEG activity during sleep,

at which time ___________________________________________________________________________________.

• Non-REM sleep• All stages of sleep except REM sleep.

• Slow-wave sleep• Non-REM sleep, characterized by synchronized EEG

activity during deeper stages.

Stages in a Typical Night’s Sleep

Hours of sleep

Minutesof Stage 4 and REM

1 2 3 4 5 6 7 80

10

15

20

25

5

Decreasing Stage 4

Increasing REM



• Basic rest-activity cycle• A 90-minute cycle (in humans) of

_________________________________________, controlled by a biological clock in the caudal brain stem; controls cycles of REM sleep and

slow-wave sleep.

If awaken during REM or stage 1 sleep, the subject feels __________.

If awaken during slow-wave sleep the subjects feels ________________.

Sleeping Like a Baby

Good sleep quality requires ______________________________________________________________.

In older adults - sleep tends to be shallower and more fragmented and the restorative effect of sleep is reduced. This is associated with reduced levels of stage ___ sleep.

Stage 4 Sleep

Quick transition from stage 1 to stage 4. A stage 4 bout typically lasts for

___minutes. Characterized by

__________________________________________________________________________

If awakened in stage 4 the subject feels disoriented.

Pulse of ________________ is released in the first two bouts of stage 4 sleep. May play a role in ____________________.

REM Sleep

Also called _____________ sleep – breathing is more shallow, heart rate and blood pressure are variable, eeg pattern is similar to the awake state, the large postural muscles are __________, increased genital blood flow.

Duration of REM bout ______________ over successive sleep cycles.

If awakened during REM the subject is NOT disoriented.


• Disorders of Sleep

• Insomnia

• Reported to affect approximately ___% of the population occasionally, and __% regularly.

• There appears to be no single definition of insomnia.

• One of the most important causes of insomnia seems to be sleeping medication.

• Insomnia is not a disease but ____________________________________________________________________________________.



• Insomnia• The goal of sleep medications should be to make the

person more ___________ the next day.• Most medications produce ______________________.• Most medications disturb the normal proportion of all

sleep stages (subjects may be REM deprived).• Improved drugs are being developed.

• Sleep apnea• Cessation of _______________while sleeping. Subject

wakes up to breathe.• Many cases of apnea are caused by airway obstruction,

and can be treated.



• Narcolepsy

• Narcolepsy• A sleep disorder characterized by periods of

__________________, attacks of cataplexy, sleep paralysis, and hypnagogic _____________.

• Sleep attack• A symptom of narcolepsy; an irresistible urge to sleep

during the day, after which the person awakes feeling refreshed.



• Narcolepsy

• Cataplexy• A symptom of narcolepsy; complete __________that

occurs during waking.

• Sleep paralysis• A symptom of narcolepsy; paralysis occurring

______________________________________.



• Narcolepsy

• Hypnagogic hallucination• A symptom of narcolepsy; ______________that

occur just before a person falls asleep; accompanied by sleep paralysis.

• Hypocretin• A peptide, also known as orexin, produced by

neurons whose cell bodies are located in the hypothalamus; ____________________________.



• REM sleep behavior disorder

• REM sleep behavior disorder• A neurological disorder in which

____________________________________________________________________________________________________________________________.



• Problems associated with slow-wave sleep

• These occur _______________

• Nocturnal enuresis• Bedwetting

• Somnambulism• Sleepwalking

• Pavor nocturnus• Night terrors



• Problems associated 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 _________________________.

• TV host Montel Williams has this disorder.


• Why do we sleep?

• Most researchers believe the function of slow-wave sleep is to permit the brain to ______.

• REM sleep appears to promote brain development and ____________, but how it might do so is not yet understood.

• The brain tends to ___________________________________________________________________________________.

• Some individuals tend to sleep better if they increase their _______________.



• Functions of slow-wave sleep• Sleep is a universal phenomenon among vertebrates.

• Only ___________________________________________________________________________________.

• Sleep appears to be essential to survival.

• One cerebral hemisphere sleeps __________ in the bottlenose dolphin and porpoise.


In dolphins, the two hemispheres sleep _______________________



• Effects of sleep deprivation

• Sleep appears to be a necessity of life.

• Restorative effects of sleep appear to be more important for the brain then the rest of the body.

• Deprivation does not appear to interfere with ability to perform ________________.

• There is no evidence of a physiological stress response to sleep deprivation.



• Effects of sleep deprivation

• Studies have reported ______________________________________________________________________________.

• Research suggests that the brain is resting during slow-wave sleep.

• Mental activity during the day appears to simulate _____________ slow-wave sleep at night.



• Fatal familial insomnia• A fatal inherited disorder that results in damage to

portions of the ______________; characterized by progressive _____________.

• Related to mad cow disease.



• 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 ____________.

REM Rebound

If deprived of REM - __________________________________________________________________________

If permitted to sleep subjects rush into REM sleep and experience longer REM bouts.

Subjects report vivid dreams when REM deprived.

Schizophrenics show fewer ___________than normals, and no REM rebound effect.

Function of REM


___________ people engage in less REM compared to normal subjects.

________ subjects engage in more REM than normal subjects.

Animals deprived of REM after a training session ______________________.

Animals spend ________ time in REM when they are learning most rapidly.

REM is associated with __________.

Sleep Across the Lifespan

Sleep & Aging

The highest proportion of REM is seen ________________________________________________________________.

Infants sleep 16 hours a day, about _______% of this is in REM sleep.

5 year olds sleep about ___hours a day, and the total hours of REM sleep matched that of adults.

60 year olds sleep about __ hours a day.

Sleep occurs when a specific neural circuit __________________.


If sleep is controlled by chemicals, these chemicals must be produced in the brain and act in the brain.

If some cells in the brain are very active they exceed the available supply of glucose, and begin to metabolize ___________ which is supplied by astrocytes. The metabolism of glycogen causes an increase in adenosine. The accumulation of adenosine increases the amount of _______________________________.

Adenosine plays a role in sleep regulation.


• Physiological Mechanisms of Sleep and Waking

• Neural control of arousal

• Acetylcholine• One of the most important neurotransmitters involved

in arousal.

• Two groups of acetylcholinergic neurons located in the pons and basal forebrain produce activation and cortical ______________ when they are stimulated (wakefulness).




• Norepinephrine• Catecholamine agonists produce arousal and

sleeplessness; effects appear to be mediated by the locus coeruleus in the dorsal pons.

• ____________________ stimulate NE activity.

• Locus coeruleus• A dark color 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.


Major noradrenergic neurons active during __________




• Serotonin (5-HT)• Appears to play a role in activating behavior; almost

all of the brain’s serotonergic neurons are found in the raphe nucleus. These neurons are located in the medullary and pontine regions of the brain.

• Raphe nucleus• A group of nuclei located in the reticular formation of

the medulla, pons, and midbrain, situated along the midline; contains serotonergic neurons.


Major serotonergic neurons active during wakefulness


• Physiological Mechanisms of Sleep and Waking• Neural control of arousal

• Histamine• A neurotransmitter implicated in the control of

wakefulness and arousal; a compound synthesized

from histidine, an amino acid.

Most ________________cause __________and they do this by blocking histamine receptors.

• Tuberomammillary nucleus• A nucleus in the ventral posterior hypothalamus, just

rostral to the mammillary bodies; contains histaminergic neurons involved in cortical activation and behavioral arousal.




• ______________• A peptide also known as orexin, produced by neurons

whose cell bodies are located in the hypothalamus; their destruction causes _____________.



• Neural control of slow-wave sleep

• Ventrolateral preoptic area (VLPA)• A group of GABAergic neurons in the preoptic area

whose activity _____________alertness and behavioral arousal and promotes ___________.

• Destruction of this area has been reported to result

__________________________________________.

Flip-flop on – subject is awake, flip-flop off – subject in slow wave sleep.


_____state



• As subjects age there is a ____________in the number of ___________receptors, and this may account for the decrement in the amount of time older adults spend in slow wave sleep.

• Neural control of REM sleep

• PGO wave (pontine, geniculate, occipital):• Bursts of phasic electrical activity originating in the

pons, followed by activity in the lateral geniculate nucleus and visual cortex, a characteristic of REM sleep.



• The executive mechanism• Neurons in the dorsal pons secrete ACh, and this

activation stimulates _____ sleep.

• Peribrachial area• The region around the brachium conjunctivum, located

in the dorsolateral pons; contains acetylcholinergic neurons involved in the _____________________.


Ach neurons in peribrachial area


The increase in firing rate of REM-ON cells produces REM sleep



• The executive mechanism

• Medial pontine reticular formation (MPRF)• A region that contains neurons involved in the

initiation of REM sleep; activated by acetylcholinergic neurons of the peribrachial area.

• Magnocellular nucleus• A nucleus in the medulla; involved in the __________

(____________________) that accompanies REM sleep.


ACh activation stimulates the brain areas responsible for all the components of REM sleep.

• REM sleep

• Neurons from the magnocellular nucleus form inhibitory synapses with motor neurons – preventing subjects from ________________.

• Because our brains keep us paralyzed and inactive, it suggests that __________________of behavior may be important in helping us ________________________________________.

• The subject does not move except for a few harmless _____________.



REM sleep inhibition is controlled by NE and serotonin


• Biological Clocks

• A ___________ must control the cycles of REM and slow wave sleep.

• Circadian rhythms and zeitgebers

• Circadian rhythm (24 – 25 hours)• A daily rhythmical change in behavior or physiological

process.

• Zeitgebers• A stimulus (usually the light of dawn) that resets the

biological clock responsible for circadian rhythms.



• The suprachiasmatic nucleus (SCN)

• Suprachiasmatic nucleus• A nucleus situated atop the optic chiasm. It contains a

_______________ responsible for organizing many of the body’s circadian rhythms.

• ______________• A photopigment present in ganglion cells in the retina whose

axons transmit information to the SCN, the thalamus, and the olivary pretectal nuclei. Reset the biological clock.


Suprachiasmic nucleus


Retina ganglion cells containing melanopsin



• The suprachiasmatic nucleus (SCN)• Each neurons in the SCN appears to have its own

_______________

• Advanced sleep phase syndrome• A 4-hour advance in rhythms of sleep and temperature

cycles, apparently caused by a mutation of a gene caused by (per2) involved in the rhythmicity of neurons of the SCN.



• The suprachiasmatic nucleus (SCN)

• Delayed sleep phase syndrome• A 4-hour delay in rhythms of sleep and temperature

cycles, apparently caused by a mutation of a gene caused by (per3) involved in the rhythmicity of neurons of the SCN.



• Control of seasonal rhythms: The pineal gland and melatonin

• ________________• A gland attached to the dorsal tectum; produces

melatonin and plays a role in circadian and seasonal rhythms.

• ______________• A hormone secreted during the night by the pineal

body; plays a role in circadian and seasonal rhythms.

• Melatonin

• Melatonin secretion from the pineal gland exhibits a circadian rhythm with peak secretion occurring just _________________.

• The administration of melatonin just before bedtime helps reduce the adverse effects of jet lag and shift work. It also helps synchronize circadian rhythms _______________________________________.


Sleeping Pills

Sleeping pills are one of the major causes of insomnia.

Pills may be ______________. Pills may prevent normal _________

bouts. Establishing adequate exercise

levels reduces the need for sleeping pills.

• Current Sleep Medications

• Ambien – short term insomnia (sedative)

• Side effects – allergic reactions: difficulty breathing, swelling of the face, lips and tongue.

• Memory impairments – subjects have no memory of driving, making phone calls or eating.

• Avoid use if you have a history of kidney disease, liver disease, lung disease, sleep apnea, depression, drug or alcohol addiction.

• Withdrawal – nausea, anxiety, panic, seizures.


• Current Sleep Medications

• Lunesta – bad taste, headache, drowsiness, urinary tract infections, dry mouth, dizziness, heartburn, pain, nausea, accidental injury, breast enlargement (in men), chest pain, anxiety, suicidal thoughts, confusion, strange behavior, heightened aggression, depression, hallucinations.

• Withdrawal – abnormal dreams, anxiety, sweating, nausea, panic attack, seizures.


Sleeping Like a Baby

Good sleep quality requires adequate amounts of _______________.

In older adults - sleep tends to be shallower and more fragmented and the restorative effect of sleep is reduced. This is associated with reduced levels of stage 4 sleep.

Establish and Defend Your Sleep Cycle

Learning disorders are associated with irregular sleep patterns.

Behavioral disorders are associated with irregular sleep patterns.

Memory disorders may be associated with irregular sleep patterns (high rates of protein synthesis during REM sleep, and pulses of growth hormone are associated with slow wave sleep).

copyright © 2008 pearson allyn & bacon inc.1 chapter 8 sleep and biological rhythms this...

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