Revised Mid-Term Sleep and Dream

Brain wave CPS's cycles per second

Alpha- 8 to 12 cps Beta 13 cps Theta 3 to 7 cps Delta 75 cps

Why might running a fever from an infection make us sleepy?

An increase in sleepiness is an early and during symptom of infections. Bacterial breakdown results in an increase of cytokines which increase eepiness and NREM (decrease REM). Interestingly these ame substances seem to play a contributing role in normal sleep! Whether or not these changes are really beneficial is less clear, but it is likely that extra sleep with more SWS enables the body to devote more resources to healing (see Krueger, 1992).Prolonged sleep deprivation ecreases natural killer cells and interleukins.

Why is coffee alerting?

Caffeine readily crosses the blood-brain barrier that separates the bloodstream from the interior of the brain. Once in the brain, the principal mode of action is as an antagonist of adenosine receptors. The caffeine molecule is structurally similar to adenosine, and binds to adenosine receptors on the surface of cells without activating them (an "antagonist" mechanism of action). Therefore, caffeine acts as a competitive inhibitor

Describe cardiovascular and respiratory activity during NREM and REM

Cardiovascular- NREM- heart rate is slow and BP lowTonic REM- heart rate and BP low and unresponsive. Phasic REM- heart rate and BP variable. BP generally higher. REM- increase in brain blood flow Respiratory- NREM- about 15% decrease in air volume. Regular and slightly deeper, resistance doubles. Tonic REM- irregular with rapid and shallow patterns prevailing. Pauses common. Compensation for resistance is weak. Cough response is suppressed

How important is a person's age in understanding their sleep

Children's sleep is impacted by:Biological processes Cultural values, parental beliefs, and social systems. Process "S" is a sleep-wake dependent homeostatic pressure marker: adults SWS, child theta Process "C" is a sleep-wake independent clock-like circadian pressure (circadian: 24 hr cycle) marker: clock. Sleep shifts from polyphasic to biphasic to monophasic as we age.

. Describe the three kinds of biological rhythms discussed in class (what are examples of each?)

Circadian rhythms are approximately 24 hours in duration. Ultradian rhythms less than 24 hours in length. 90 minute sleep cycles are ultradian. Some other ultradian cyclings of the body are hormonal release, heart rate, thermoregulation, urination, bowel activity, nostril dilation, and appetite. Infradian rhythms are greater than 24 hours in length. e.g. menstruation

. How do we maintain our circadian rhythm and what happens if you experimentally are placed in a cave with no time cues (know the special word for time cues

Circadian rhythms do not require external cues such as changes in light. Zeitgebers, or time synchronizers in the environment, help us maintain a 24 hour circadian cycle. Free running circadian cycles are slightly longer than 24 hours.

What role does the thalamus play in sleep (use plain language to demonstrate your understanding)

Cortical responsiveness to stimuli is reduced to 80% during stage 1 & 2, 65% during SWS, and over 90% during REMS. Much reduced responsiveness is due to inhibition in the thalamus. McGinty and Szymusiak (2000) have identified a small group of cells in the hypothalamus (VLPO) that become very active at sleep onset

A PSG study can be conducted at home

False

As we grow older we need less sleep

False

K- complexes can be seen in EOG

False

Naps are unhealthy

False

What are REM-on cells?

Greater *overall* activation is found in the brain during REM sleep than waking! Lesion studies (in cats) have demonstrated that the pons is necessary for the production or REM sleep. Specifically, lateral posterior REM-on cells.

. Why do we continue to use the EEG, EOG, and EMG technology for defining states of consciousness (e.g. sleep)?

Historical precedent. They were among the earliest measures used to discriminate sleep and sleep stages. - . Relative ease of measurement. Little specialized equipment is needed, and they can be recorded from surface electrodes. - Discriminating power. The EEG, EOG, and EMG in combination do a pretty good job of discriminating sleep from wakefulness and the different sleep stages

How did we discover that sleep is NOT sensory deprivation?

Lindsley et al. found lesions of reticular formation (not sensory pathways) resulted in permanent sleep. Moruzzi and Magoun (1949) showed activating the ascending reticular activating system resulted in wakeful EEG Batini (1958) repeated research to Bremer with cuts through mid pons and found no sleep effect. Cuts lower did. Conclusion is that something in lower brainstem is actively responsible for sleep.

How is tryptophan related to serotonin?

Many people began taking a dietary supplement of tryptophan in the 1980s as a way to treat insomnia, but the U.S. Food and Drug Administration banned tryptophan supplements in 1990 because of an outbreak of eosinophilia-myalgia, a syndrome that causes muscle pain and even death. The FDA said contaminated tryptophan supplements caused the outbreak [source: FDA].

What role does serotonin play in sleep?

May facilitate sleep onset by dampening brain's response to sensory input. Serotonin precursor, tryptophan, may mildly facilitate sleep.

What is melatonin? How do we know melatonin is not responsible for all sleepiness? When is melatonin best prescribed?

Melatonin is a hormone released by the pineal gland and is mildly sleep promoting as a zeitgeber. It is released at night and bright light blocks its release.

Greek god of dreams

Morpheus

Describe energy use of the brain during NREM and REM.

NREM sleep is mostly quiet. REM sleep is characterized by irregular activation. Signals are sent but overridden by the brainstem (independent of any feedback!).

Describe ANS activity during NREM and REM.

NREM sleep- active PNS, quiet SNS

Sleep walking and sleep during what stage of sleep

Non-Rem stage 3 or 4/ deep or SWS

How does pain affect sleep?

Pain, acute or chronic, clearly affects sleep and visa versa! People in pain have more difficulty getting to sleep, have less SWS, and more wakenings. Not surprisingly, other sensory stimuli may disrupt sleep as well (smell?).

Why do we believe sleep is not just rest?-

Parts of our brain are actually more active! Increased waking activity does not reliably produce more sleep. Less activity does not produce less sleep (if anything, it increases the urge to sleep).

What are preschool, school age, and adolescent sleep phenomenon

Pre school Lifestyle" cosleeping and "reactive" cosleeping Transitional objects, Separation anxiety ,Bedtime resistance. School age- Circadian sleep phase preference develops ("normal" bedtime?) Sleep hygiene behaviors become established. Adolescence- Sleep phase delay Insufficient weekday sleep Weekend "make-up" sleep

How do we know we need sleep

Rebound Sleep as a Restorative Process .Restoration of wear and tear that occurs during wakefulness.

Penile tumescence occurs during what stage of slle

Rem

What pathology may be expected as we age

SWS phenomenon such as night terrors and somnambulism occur in about 3-5% of school-aged children and decrease in adolescence. Bedwetting occurs in 10% of 4 year olds, but only 3% boys and 1% girls by age 8. Narcolepsy begins in adolescence. In adulthood insomnia is reported by about 25% by age 30 and 50% by age 70. PLM and apnea occur in 20-30% of those over 65. Another author suggests the figure is 45% vs. 5-6% in younger adults. RLS increases with age. Risk for REM Sleep Behavior Disorder (RSBD) increases In the neonate (< 4 weeks) Sudden Infant Death Syndrome (SIDS)

What stage of sleep predominates for the newborns

SWS- slow wave sleep

What do we know about sleep and thermoregulation (esp. REM sleep)?

Sleep and Thermoregulation Sleep provides an opportunity for the animal to lower its thermostat, thus reducing the number of calories it must expend to maintain body temperature. Endothermy is very costly.

What is a SOREMP

Sleep onset REM Period- 15 minute narcolepsy infants 1st 3 months

When a subject closes their eyes what EEG pathern should we see

Slow rolling - Beta waves

. Why do we sleep (what are the theories)? Another theory: Sleep as an Adaptive Response

Some experts suggest sleep may primarily just keep a way to keep an animal out of harms way when there is nothing important to do (when not hunting be quiet and safe).

Describe hormones and sleep.

Stress causes an increase of several hormones including cortisol which can disrupt sleep continuity and stages. Cognitive aspect of stress may impact insomnia.

How do we measure sleepiness (subjectively and objectively; know details of each)

Subjective measures- Epworth Sleepiness Scale, (ESS) Stanford Sleepiness Scale (SSS), Visual Analog Sleepiness Scales Objective measures- Multiple Sleep Latency Test (MSLT),Maintenance of Wakefulness Test (MWT)

What and where is our circadian clock and how does it work?

Suprachiasmatic Nucleus instructs thepineal gland to release melatonin Please note that the story of sleepiness is much more complex than the author of your textbooks tells us. Melatonin only plays small part in the story of sleep and sleepiness. If melatonin were the answer, we'd have the mystery of sleep solved!

circadian rhythms and the suprachiasmatic nucleus.

Suprachiasmatic nucleus (SCN) is the location of the circadian clock. If a SCN is implanted circadian rhythms take on the periodicity of the donor. Entrainment is the process of shifting the intrinsic SCN period. Main zeitgerber is light traveling on its own pathway from the eye. The SCN influences other areas of the brain, especially the pineal glad and its production of melatonin.

What does cps (cycles per second) really mean in plain language? -

The EEG captures the four types of brain waves that occur during wakefulness and sleep, which are measured in cycles per second (cps): Beta waves occur during daily wakefulness. They have the highest frequency and the lowest amplitude, compared to other waves. ... Delta sleep is the deepest sleep.

what are the symptoms of sleep deprivation?

The effects of total (continuous) sleep deprivation include changes in emotions, behaviors (including) microsleeps), and mental processes as well as biological effects (see table 2). The effects of sleep deprivation can only be temporarily overcome. The effects of partial sleep deprivation can accumulate and be as serious as total sleep deprivation

How does sleep change as we age

The newborn sleeps about 16 to 18 hours per day. This is assumed to be a restitutional response to intense growth. By 16 weeks through fist year sleep drops to 14 or 15 hrs per day. A gradual decline to 10 hrs per day between third and fifth year. Whether sleep behaviors in young children are considered problematic depends a great deal on parents' perceptions and expectations.

To remain awake your brain primarily relies on what system?

To remain awake your brain depends on activation primarily from the ascending reticular activating system (ARAS), the locus coeruleus, and the raphae.

What is tonic and phasic REM?

Tonic REM- active PNS, very quiet SNS Phasic REM- active PNS, storming SNS

What role does tryptophan play in classic postprandial thanksgiving sleepiness?

Tryptophan in turkey probably won't trigger the body to produce more serotonin because tryptophan works best on an empty stomach. The tryptophan in a Thanksgiving turkey has to vie with all the other amino acids that the body is trying to use. So only part of the tryptophan makes it to the brain to help produce serotonin.

What is the most likely circadian change in old age

advancement due to deterioration due to deterioration of hypothalamic nuclei

How does the need for sleep change as we

age Sleep shifts from polyphasic to biphasic to monophasic as we age. (This is often thought of by the lay person in terms of decrease in napping, 3-5 years; probably how napping got such a bad rep, i.e. grownups don't nap)

Describe a k - complex

an EEG shows a large jump immediately followed by drastic drop in amplitude

Our sleep shifts from polyphasic to _____________ as we age

biaphasic to monophase

process C that drives sleep

circadian clock

Describe 3 sleep changes that occur in old age

declining growth hormones melatonin level decrease sleep latency increases

Slow wave sleep first appears at about what age

early childhood

Alligators sleep

false

Muscles may twitch during REM sleep

false

Why use 3 EMG electrodes

grounded when 2 + voltage electrodes can be recorded

3 reasons to still use EEG, EOG, EMG

historical precedent ease of measurement discriminating power

Process S that drives sleep

homeostatic process

What is a hypnic myoclonia?

hypnic jerk or sleep twitch

Cycles of a duration longer than 24 hours, such as menstrual cycle are called

infradian cycles

The most prominent occipital bone projection, notch, at the back of the head is referred to asthe _

inion

the effects of sleep deprivation on the body

insufficient sleep reduces the functioning of the immune system increase susceptibility cold, and renders vaccinations.

Who was Alfred Maury

interpreted dreams and external stimuli French scholar and psysician predated Sigmund Freud

What is Orexin/Hypocretin?

is a peptide released by the lateral hypothalamus It has been shown to be released into many areas of the brain important in the control of sleep/waking (esp REM). A lack of matched receptors may result in narcolepsy.

Behavioral definition of sleep

little movement reduced response to stimuli reversibility stereotypical/ species specific posture

How is movement inhibited in REM? Is breakthrough REM movement possible?

mong other processes, REM-on cells stimulate parts of the medulla to use glycine to prevent activation of motor neurons. Motor impulses are generated, but blocked (some may break through esp. in nonhuman animals and infants.

Where are the EOG leads placed

on the outer side of each eye

what is the nasion

point between forehead and nose

Describe three reasons we may sleep

repair and restore brain memory storage dumping rebound

what is SEM and when do you see it

slow eye movement

Sleep spindles occur during

stage 2 sleep

The EEG pattern of stage 1 sleep is primarily what

theta waves

6 or 7 waves in .5 seconds is called a sleep spindle

true

All mammals sleep

true

Half a brain can sleep

true

Some adults over 75 experience only REM sleep

true

we almost exclusively dream in Rem

true

Who developed Multiple Sleep Latency Test

William C. Dement and Mark Carshadon

What is Randy Gardner's story?

World record holder for sleep deprivation without stimulants. Stayed awake for 264 hours, 11 straight days. He was 17 years old. 1964 (too unsafe to replicate

What is the German word for time synchronizer

Zeitgebers

What is μV?

a unit of electromotive force or potential difference equal to one millionth of a volt.

How long are sleep cycles

about 90 minutes

newborn REM sleep is also called

active sleep

Borbely's-

- two process model with an ultradian rhythm added. Three major processes underlie sleep regulation: a homeostatic, a circadian and an ultradian process. W, waking; S, sleep; N, nonREM sleep; R, REM sleep. The progressive decline of nonREM sleep intensity is represented both in the top and bottom diagrams (decline

review our biological rhythms and biological clock

. Circadian rhythms are approximately 24 hours in duration. Ultradian rhythms are greater than 24 hours in lengths. Infradian rhythms are shorter than 24 hours in length. 4.

What are slow rolling eye movements (sometimes just referred to as rolling eye movements)?

)? Happens in Stage 1 sleep EEG Theta activity 3.5-7.5 Hz heralds true onset of sleep, subject may report that they have not slept (in stage two also) EOG rolling eye movements, EMG moderate to low

5. How does sleep architecture mature (esp. with regard to REM sleep)?

)? In the first 6 months after birth REM sleep is referred to as active sleep (twitches and jerks break through muscle inhibition) NREM sleep is referred to as quite sleep SWS emerges at about 3 months Stages 1-4 can be identified at 6 months of age Sleep spindles appear at 4 weeks K complexes appear at 6 months. In the first 6 months after birth REM sleep is referred to as active sleep (twitches and jerks break through muscle inhibition) NREM sleep is referred to as quite sleep SWS emerges at about 3 months Stages 1-4 can be identified at 6 months of age Sleep spindles appear at 4 weeks K complexes appear at 6 months. Alternation of NREM to REM occurs at 50 to 60 min intervals in infants, 90-110 min for school age, and about 90 min for adults Infants may have SOREMPs (disappear after 3 months) Percentage of REM remains constant (small 2-3% decrease middle to old age) Alzheimer's disease may result in reduced REM

What are the brainwaves associated with each stage of sleep and the two brainwaves associated with each type of wakefulness?

- Activated/Alert or Beta Waves EEG desynchronized low voltage (about 10-30 microvolts) fast (16-25 Hz). EOG REMs may be abundant or scarce, depending on the amount of visual scanning. EMG may be high or moderate, depending on the degree of muscle tension. Relaxed or Alpha Waves (yeah!) EEG synchronized (sinusoidal) slightly higher voltage (20-40 microvolts) slower (8-12 Hz) EOG might include some rolling eyes. EMG more relaxed.

Describe sleep in old age.

. Inability to phase-shift readily Daytime napping (no change in total sleep time) Lark-like tendencies (advancement of circadian rhythm; due to deterioration of hypothalamic nuclei? ) Inability to sustain long bouts of waking and uninterrupted sleep Inconsistency in external cues Melatonin levels decrease Older subjects fall asleep and wake up earlier in relation to their night melatonin secretion (wake when melatonin levels are still high). This suggests factors some synergistic effect and/or third variable. Over 50% of older adults complain of difficulty sleeping Co-morbid medical conditions are often to blame. Pain (arthritis, joint injury, broken bones) Neurological disorders (RLS, dementia) Organ system failure (pulmonary disease, incontinence)' Mood disorders (depression, anxiety) Medication may interfere with sleep. Menopause Sleep latency increases 8 to 12 minutes Hot flashes increase the number of awakenings Hormone replacement improves subjective but not objective sleep measures. Increased prevalence of sleep apnea events Decreased respiratory muscle strength Decreased expiratory flow rates Diminished compliance of the chest wall Changes of lung Changes in the anatomy of the airway Airway and soft palate become longer Pharyngeal fat pads increase in size Shape of bony structures around pharyngeal airway changed

. Describe REM sleep in infancy

. Infancies stay in REM sleep 70% of the time and are in NREM sleep 20-25% of the time.

The international system of electrode placement is called the

10-20 system

normal adult sleep spindles have frequency of

12 to 14 Hz

The most common epoch length

30 or 60 seconds

. What are the symptoms of sleep deprivation

? Excessive sleepiness Negative mood changes Learning & Memory Problems Reduced performance on standardized tests Increased accident risk Acute negative effects on glucose metabolism Acute negative effects on immune function Hyperactivity in children

. When and by whom was REM sleep discovered

? REM sleep discovered in 1952 and Eugene Aserinsky, Nathaniel Kleitman, and William C. Dement. - 14. Describe REM sleep in infancy. Infancies stay in REM sleep 70% of the time and are in NREM sleep 20-25% of the time.

. Why do we say sleep is an active process

? Sleep is an active process Sleepiness and alertness are controlled by a biological clock Sleep disorders are numerous and profoundly important

3 measurable sleep correlates

EEG- brain waves EOG- eye movement EMG- muscle tension

Explain, the brain is functionally reorganized in sleep.

Early research (Bremer 1935,36) involved the removal of sensory stimuli from cat brains. Moruzzi and Magoun (1949) showed activating the ascending reticular activating system resulted in wakeful EEG

Who discovered REM sleep

Eugene aserinsky and Nathaniel kleitman

What are all the characteristics that make REM sleep different from NREM sleep and why is it sometimes referred to as paradoxical sleep?

In REM sleep -After about 90 minutes EEG desynchronized, some theta waves, eyes are darting rapidly back and forth. EMG silent. Usually report dreaming. Brain is very active. Cerebral blood flow and oxygen consumption are accelerated. Penile tumescence and vaginal tumescence (may be used to assess physiological potency).

How do we physiologically define sleep (make sure you understand EEG, EOG, and EMG well, including how to spell, why each one works, and the relevance of each during each stage of sleep)?

Using a polysomnography- Measurements are made of brain activity (electroencephalogram; EEG), eye movements (electro-oculogram; EOG), muscular activity (electromyogram; EMG), respiration, oxygen level in the blood, and other possibilities. He found that small changes in voltage between two small bits of metal, called "electrodes", place on the scalp. These voltages are millionths of volts and must be amplified The occur in waves and both the duration, expressed as Hz (cycles per second, cps), and amplitude, expressed in microvolts (millionths of a volt) are measured. The exact physiologic bases of the voltage variations are not entirely known, but it is believed that they emanate largely from changes in voltage of the membranes of nerve cells. Electrooculogram- The EOG is a record of eye movements. Since the eyeball is like a small battery, with the retina negative relative to the cornea, an electrode placed on the skin near the eye will record a change in voltage as the eye rotates in its socket. Electromyogram- conventionally abbreviated as "EMG," is a record of the electrical activity of muscles. It may also be recorded from electrodes on the skin surface overlying a muscle. In humans during polysonmography, the EMG is typically recorded from under the chin, since muscles in this area show very dramatic changes associated with the sleep stages.

Describe what we know about temperature (body and environmental) and sleep?

When you sleep your body temperature drops to its lowest level. If you remain awake your body will experience half average temperature drop. During NREM your body regulates temperature. During REM your body does NOT regulate temperature (e.g. sweating or shivering). If you get too cold or hot during REM you will awaken. There is a minor drop body temperature in mid-afternoon. People sleep best when room temp is 84F (with no covers or clothes). Too cold- waking increases, sleep time decreases, sleep latency decreases, movements increase, and decrease in REM and stage 2. Too hot- waking increases and more fragmentation. Body temperature at sleep onset, when slightly higher than normal, may feel sleepier, sleep a bit longer, and get more SWS.