Sleep and and arousal lecture 12

biological rhtyms are

regular fluctuations in a living process

T/F Many animals show daily rhtyms in activity

True

The _______ houses a circadian clock

the hypothalamus

Some biological rhythms are _____ or ______ than a day

longer or shorter than a day

Human sleep exhibits

different stages

our sleep patterns change

across our life span

manipulating sleep reveals an

underlying structure

biologiical rhtyms can vary in

length or "period"

circadian rhythms

24 hours

Ultradian rhythms

repeat more than once a day, such as feeding, and hormone release

Infradian rhythms

less than once a day, body weight and reproductive cycles

diurnal

active during the day

circadian rhythms are those functions of living organisms that display a rhythm of

24 hours

Nocturnal

active at night

circadian rhythms may be _____, ______ or , _______

behavioral, physiological, or biochemical

many physiological process change over the course of the day such as

temp, hormone levels, drug sensitivity

circadian rhythms are generated by an __________

internal or endogenous clock

free-running

animal maintains its own cycle without external cues such as light

period

time between two similar points on successive cycles, may not be exactly 24 hours

phase shift

shift in the activity in ressponse to a synchronizing stimulus such as light or food

entrainment

process of shiifting the rhythm

the cue that an aminal uses to synchronize with the environment is called a

zeitgeber (time giver)

biological clock is found in the _________ which is located above the ________ in the hypothalumus

suprachiasmatic nucleus (SCN) above the optic chhasm in the hypothalamus

circadian rhythms are disrupted in animals with

SCN lesions

isolated SCN neurons can maintain electrical activity synchronized to

previous light cycle

transplant studies proved that __________is generated in the SCN

endogenous period is generated in the SCN

hamsters with SCN lesions received SCN tissue transplant with very short rhhtyms and eventually what happened?

circadian rhythms were restored but matched the shorter period of the donor

in mammals, light info goes from eye to SCN via the

retinohypothalamic pathway

the retinohypothway constists of __________ that project to the SCN

retinal ganglion cells

Ganglion cells on retinohypothalamic pathways d not rely on rods and cones, they contain special photopihment:

melanopsin

melanopsin

a photopigment that is sensitive to ambient light

SCN cells make two proteins:

clock and cycle

Clock and Cycle bind together to form a _________

dimer

dimer promotes transcription _______ (per) and _____ (cry) genes

period and cryptochrome

per and cry proteins outside of nucleus _____ and inhibit transcription of ____ genes

dimerize, and inhibit transcription of clock and cycle genes

no new Clock/cycle proteins are made until the per/cry proteins degrade, this takes

cycle takes 24 hours

when melanopsin contains retinal ganglion cells detect light they release ________ in the ______, this entrails molecular clock to the day and night cycle

release Glutamate in the SCN

glutamate release promotes _________ whic shifts the clock and the _______

promotes per production, which shifts the clock and the animals behavior

True or False:

"Night owls" and "morning people" likely carry different versions of the clock and per genes

True

Mice with double mutation in clock gene show servere ______ in constant light conditions but appear nrmal with acess too _______ cycle

show severe arrhythmicity in constant light conditions but appear normal with access to a light dark cycle

sleep is synchronized to ________, including light and dark

external events

stimuli like lights, food, jobs and alarm clocks entrain us to

be awake or to sleep

in the absence of cues, humans have a free running period that approximately is

25 hours depends with age

result of human free run experient:

free running rhtyms slightly longer than

74 nights of sleep in ____ day s

slightly longer than 24hrs,

74 nights of sleep in 77 days

electrical brain potentials can bbeused to classify levels of ______ and states of ______

levels of arousal and states of sleep

Electroencephalogram (EEG)

records electrical activity in the brain through electrodes placed on the outside of the skull

Electro-oculogram (EOG)

records eye movement

Electromyography (EMG)

records muscle activity

eeg pattern activity in an awake person contains many frequencies known as :

beta activity or desynchronized EEG

Slow wave sleep (SWS) divided intto _____ that have characteristic activity patterns

three statges

Stage 3 sleep is called ________ defined by large amplited very _____ _____ waves

called slow wave sleep (SWS) defined by large amplitude, very slow delta waves

What are two distinct classes of sleep

Slow wave Sleep (SWS) and Rapid eye movment (REM)

Slow-wave sleep (SWS) can be divided into _______ stages is characterized by ______ EEG activity

into 3 or 4 stages and is characterized by slow wave EEG activity

Rapid eyemovement (REM) sleep is characterized by _______, _____ EEG waves, ___ posterial tension (EMG) and _____ eye movements

characterized by small amplitude, fast EEG waves, no postural tension EMG, and rapid eye movements

Rapid-eye movement sleep (REM) eeg activity is similar to person who is ______, but muscles are _______, brainstem regions are profoundly _____ motor neurons

similar to awake person, muscles are limp and relaxed

brainstems regions are profoundly inhibiting motor neurons

REM sleep is characterized by rapid __________, irregular breathing and ____, and _____

rapid eye movements under closed lids, irregular breathing and pulse rates, and vivid dreams

REM Sleep:
____ EEG with small amplitude, high frequency waves like ______


muscles are ______, they are flaccid and ______

Active EEG with small-amplitude, high frequency waves, like an awake person

Muscles are relaxed, flaccid and unresponsive

REM sleep is sometimes called paradoxical sleep because

of mismatch between brain activity that resembles an awake person and lack of muscle activity

awake is a mix of many frequencies, dominated by fast and ______ , called _______

fast and low amplitude frequencies, called desynchronized EEG

awake EEG patterns look similar to _______ sleep and ______ sleep

stage 1 sleep and REM sleep

delta waves =

deep sleep

dolphins don't have REM sleep because

they cannot relax all muscles, they need to go up to surface to relax

dolphins and birds: only one brain of hemisphere enteres SWS, other hem

stayes awake

in dolphns and birds, only one hem in deep sleep allows them to continue functioning but

they can rest half of brain while moving

vivid dreams occur during ______ sleep, characterized by: 1. and 2.

occur durin REM sleep, characterized by visual imagery and sense that the dreamer is "there"

nightmares awaken sleep from

REM sleep

night terrors are sudden arrousals from stage ____ (___)) marked by fear and autonmic activity, occurs

sudden arousals from stage 3 or 4 SWS, within 2 r 3 hours of falling asleep

true or false: Night terrors can be induced by drugs

true

REM behavior disorder

a rare disorder in which the mechanism that blocks the movement of the voluntary muscles ____, allowing the person to ___________

a rare disorder in which the mechanism that blocks the movement of the voluntary muscles fails, allowing the person to thrash around and even get up and act out nightmares

Young adult sleep:
7-8 hours
_______% is stage 2 sleep, and ______ is REM sleep
cycle lasts _______ but cycles early in night have more ______ SWS, and later cycles have more _______ sleep

45-50% stage 2, 20% is REM sleep
lasts 90-110 mins, have more stage 3 SWS, and later cycles have more REM sleep

at puberty, most people shift circadian rhythm so they get up

later in the day

later stats improved ______ and _______, and reduced ____- and in class sleeping

improved attendance and enrollment, and reduced depression and in class sleeping

as people age, total time asleep ______ and number of awakenings _____

total time asleep declines, and number of awakenings increases

more REM sleep (~50%) during infancy, thought to provide essential stimulation to developing

nervous system

physiological function of REM sleep:

dreams provide sleeping brain with periodic stimulation to develop and preserve neural pathways

most dramatic decline is loss of time spent in

stage 3 sleep

at age 60, only half as much time is spent in stage 3 compared to at age 20, by age 90 stage 3 has

disappeared

Effects of sleep deprivation

Increased irritability
Difficulty in concentrating
Episodes of disorientation

total sleep deprivation can compromise _______ and leads to death

compromise immune system and leads to death

disease fatal familial insomnia is

inherited

in midlife people stop sleeping (with familial insomnia) and die 7-24 months after onset of insmonia

autopsy of person with familial insomnia shows degeneration of

cortex and thalamus

Energy conservation function of sleep

1. muscular tension, heart rate, blood pressure, temperature, and rate of respiration are reduced
3. replenish metabolic requirements, most growth hormone is released during SWS, immune function

sleep durng interval between learning and recall may reduce

interferining stimuli

niche adaptation function of sleep

2. avoid predators, awake to eat

body restoration

3. replenish metabolic requirements, most growth hormone is released during SWS, immune function

1. energy conservation
2. niche adaptatin
3. body restoratioh
4. memory consolidation

memory typically decays, sleep

sleep slows this down

sleep, especially REM, may actively contribute through processes that consolidate

learned material

patterns of neuronal activity seen while a task is being learned during wakefulness are recreated uring

subsequent SWS

a cue has been used to ______ learning during _____ sleep

a cue has been used to reactive learning during SWS

Sleep is an active state mediated by:
1.
2.
3.
4.

forebrain, brainstem, pontine, hypothalamic system

forebrain system by itself displays

SWS

brainstem systems that activates the

forebrain into wakefulness

pontine system that triggers

REM sleep

hypothalamic system that affects

other three systems

transection experiments showed that diffrely sleep systems originate in

different parts of the brain

isolated brain is made by an incision between the

medulla and spinal cord

animals showed signs of sleep and wakefulness, proving that

netowkrs reside in brain

isolated forebrain made by incision in

midbrain