1how many stages of sleep are there ?
5 stages
2what are the 5 stages of sleep ?
1. awake
2. REM sleep
3. stage 1 sleep
4. stage 2 sleep
5. stage 3/4 sleep
3what waves does an EEG show when we are awake ?
alpha / beta
4what waves does an EEG show when we are in stage 1 ?
theta
5what waves does an EEG show when we are in stage 2 ?
theta
6what waves does an EEG show when we are in stage 3/4 ?
delta
7what waves does an EEG show ehrn in REM sleep ?
beta waves
8what is paradoxical sleep ?
paradoxical sleep : similar to being awake but without muscle activity
9how long is each sleep stage ?
stage 1 : 10 minutes
stage 2 : 15 minutes
stage 3/4 : 20 + 45 minutes
REM sleep : 20 minutes
10how often does REM sleep occur ?
every 80/90 minutes
11in which stage of sleep will you think you were not sleeping ?
stage 2
12what does REM stand for?
rapid eye movemnt
13what is POG waves ?
ponto geniculo pccipital waves
14when can we see POG waves ?
just begore REM sleep
15were in the brain can POG waves be seen ?
in the pons to the lateral geniculate nucleus (LGN) and the primary visual cortex
16where is the LGN ?
the thalamus
17why do we have visual cortex activity in REM sleep ?
due to dreaming
18what are the charcaterisitcs of REM sleep ?
1. paralisis skeletal muscle
2. increased genital activity ( non erotic )
3. strong suppresion of exteranl stimuli
4. narrative dreaming ( story like )
5. at waking , immediatly alert
6. high probability of waking up spontaneously
19what are the chances of dream recall ?
75% to 95%
20when do we usueally weak up ?
after REM sleep
21why is there no logic continuity in space or time after waking up from REM?
due to absence of frontal lobe activity
22what are the charcteristics of stage 3/4 of sleep ?
1. strong suppresion of external stimuli
2. low probability to wake up
3. at waking : drowsy and disorinted
4. dream recall 20 % chance
5. fragmetry dreams with strong emotion : nightmare
23in which stage are we most probably to have nightmares ?
stage 3/4
24what are possible symtoms of sleep deprivation ?
loss of thermoregulation
increased fat and glucose in methabolism
severe weightloss
imune system distruption
death
25how can volutary sleep deprivation show effects of lack of sleep ?
volutary not sleep more than 10 days
*no problem of physical efforts
*no physiological stress
→ physicological recovery not the main function of sleep
26how can sleep deprivation lead to cognitive problems ?
concentration
perception
hallucinations
27what could be considered one main function of sleep ?
brain recovery
28if there is sleep deprivation which stages are caught up ?
stage 3/4 but the others not
29which sleep stage appers to be the most important ?
stage 4
30what is the function of slow wave sleep ?
1. restortive
2. build sugar supply
3. clear chemicals in brain
4. learning
31what is the sugar supply function of sleep stage 4 ?
glycogen in astrocytes : fuel brain cells
32what are the chemicals in the brain cleared in sleep stage 4 ?
adenosine
33what is adeosine ?
inhibits neutral activity when glycogen is low
34which type of memory does stage 4 of sleep consolidate ?
declarative memory ( events you can talk about)
35which sleep stage reduces in proportion when we age ?
REM sleep
36what is the main function of REM sleep?
brain development as we age we need less and less development
37which type of learning does REM sellep consolidate ?
non declarative
38which substance accumulated in the brain while we walk ?
adeosine
39what is adeosine ?
a sleep promoting chemical
40what are the four chemicals that promote wakefullness ?
1. acetylcholine
2. Neopinephine
3. Serotitonine
4. Histamine
41in which parts of the brain can acetylcholine be found ?
pons , basal forebrain, septum hippocampus
42in which parts of the brain can neopinephrine be found ?
locus coeruleus in pons
43in which parts of the brain can serotonine be found (5htp) ?
raphe nuclei in medulla and pons
44in whcih parts of the brain can hystamine be forund ?
tuberomammillary nucleus in hypothalamus
45where is the orexin system ?
lateral hypothalamus
46what is the role of orexin ?
stabilize the flip flop, they can activate the arousal systems and keep awake
47what is vIOPA ?
system that promotes sleep arousal
48where is the vIPOA system ?
anterior hypothalamus
49when is the vIPOA inhibited ?
when we are awake , walking
50what is the flip flop system ?
**consists of 2 sets of mutually inhibitory components**
The sleep side is the VLPO, and the arousal side includes TMN histaminergic neurons and brainstem arousal regions
51when is the sysflip flop system off ?
when the vIPOA is activates → promotes sleep
when rhe brain stem and forebrain are inhibited
52when is the flip flop system on ?
when the vIPOA is inhibited
when the brain stem and forebrain arousal system is activates → promotes wakefulness
53what is the advanteg of the flip flop system ?
fast transition between sleep and wakefulness
54what are the disatvantages of the flip flop system ?
can be insatiable , you suddenly fall asleep of wake up many time
55what receptors do vIPOA neurons have ?
adeosine receptors
accumulation of adenosine during the day promotes sleep
56what stimulates waking up ?
1. biological clock
2. hunger signals
orexin actionvation
= flip flop on
57what stimulates sleep ?
inhibition of orexine
accumulation of adeosine
= flip flop off
58what blocks adeosine receptors ?
caffeine
59when is the REM flip flop on?
sublaterodorsal nucleus (SLD) ventral w.r.t LC
60when is the REM flip flop off ?
ventrolateral PeriAqueductal Gray matter (vIPAG)
61what is "atonia " ?
**lack of tone or energy; muscular weakness, especially in a contractile organ**
62what is the porcess of interaction between slow wave and REM sleep ?
sleep begins after activation vIPOA
↓
vIPOA inhibits orexinergic neurons and REM OFF region
↓
REM
63ON region becomes activated : start REM sleep
64what other factors can activate REM on ?
emotional stimulia via amigdala
( brain interprets emotion as start of a dream )
65what possible sleep disorders are there ?
1. slow wave sleep
2. REM sleep
3. instable flip flop
66what slow wave sleep dicorders are there ?
1. somnabulism
2. nocturnal euresis
3. parov nocturnus
67what is sleep euresis ?
bed wetting
68what is somnambulism ?
sleepwalking
69what is parov nocturus ?
nightmares
70what REM sleep discorders are there ?
REM sleep behaviour disorder
71what flip flop disrders are there ?
narcolepsy
72what is REM sleep behaviour ?
dream is acted out
73what is narcolepsy ?
1. sleep attacks ( need to sleep )
2. cataplexy ( atonia during walking )
3. pre en post sleep paralysis
4. hypnagogic hallucinations
74what are possible causes of nacolepsy ?
human patients the neuropeptide orexin appeared to be missing in the CSF
orexin gene knock out or a poison that kills orexinergic neurons
75what is movie cataplex ?
sudden activation motor inhibition mechanism your body will suddenly paralysed
76what triggers movie cataplex ?
in particular triggered by emotions ( brain thinks REM sleep begins)
77what is the sleep wake pattern called ?
circadian
78what synchronisez the circadian ?
light + zeitgeber
79what are zeitgebars ?
sound
temperature
social interactions
eat/drink pattern
there is an internal biological clock ( 25 hours rhythm)
80where is the internal biological clock localised ?
suprachiasmatic nucleus (SCN ) of the hypothalamus
81what leads to loss of sleep wake cycle ?
leasions in the SCN
82what is the mechanism of the internal clock ?
modulation concentration of proteins in the SCN cells that influence the firing rate of the cells
83what is the order of internal clock mechanism ?
production protein in SCN cell
↓
protein enter cell nucleus and inhibits gene that causes ints own production
↓
protein concentration decreases and gene becomes active again
there are at least 7 genes/proteins involved in the process
how many proteins are involver in the internal biological cloack function ?
at least 7
84what factors influence the sesonal rythm ?
1. testotserone
2. melatonin
85how does melatonin influence rythm ?
pineal gland produces melatonin in the dark, light inhibits the production
longer nights more melatonin more rest/sleep reduces testosterone