25. Sleep and EEG Flashcards
the bodys clock is located in the suprachiasmatic ?
nucleus (SCN)
*strong gene component
Clock CLK gene with no circadian rhythm and BMAL1 (increases at night) increase transcription/tranlation of period genes 1,2,3 and cryptochrome genes 1/2 which will continue on to do what to CLK and BMAL1?
inhibit the action of them
So during the night, BMAL/CLOCK rise and shortly after so do CRY/PER, and then during the day the BMAL CLOCK decrease first and then?
CRY/PER = circadiam rhythm
What is the cause of morning and night people?
CLK gene mutation
The SCN creates days that are 25 hours long and we match our active / inactive periods to day and night cycle of external envrionment HOW?
Retinohypothalamic tract
Light / Dark information using different receptos like melanopsin in the eyes travel via the direct relay retino- hypothalamic tract and goes to the brain where glutamine is released for _______ and melatonin is released for ______…
Glutamine = light = day melatonin = dark = night
During day, RHT to SCN inhibit pineal gland and at night the pineal gland is not inhibited d/t lack of glutatmine and it releases?
melatonin to sign night/dark
An EEG is the summated action potentials of millions of neurons in the human brain, usually low voltage, high frequency and differes over different parts of the?
brain
EEG changes with activity, arousal/awareness, sensory input, most of the time being no distinct pattern; clear patters are often considered?
pathological
What are the normal waves? A B G Theta and?
Delta
What waves have the following characteristics?
8-13Hz (cycles per second)
50uvolts (small)
Occur during quiet wakefullness (thinking) WITH EYES CLOSED
Alpha waves
Alpha waves are most prevalent in the OCCIPITAL cortex and disappear during sleep. Origin: requires connection between thalamus and cortex, GABAergic neurons FORCE coordination of neuronal activity; feedback oscillation between the thalamus and what creates waves?
thalamus and cortex
What waves have the following characteristics?
14-80Hz
<50uvolts
Occur during alert wakefullness with EYES OPEN
Beta waves
What is it called when the eyes are opened, alpha waves cease, beta waves begin and persist as long as alert?
Alpha block or alerting response
Beta waves are most prevelant in the front and parietal cortex and have an origin the same as alpha, sensory inputs do what to the oscillation?
Disrupt
What waves have the following characteristics?
30-80Hz
occur when individual is aroused or focused
especially prominent when planning motor response
require hippocampus maybe
Gamma waves
What waves have the following characteristics?
4-7Hz
100 uvolts
normal in children, over parietal/frontal cortex
in adults occur with frustration, disappointment and sleep
Theta waves
What is important to know about the origin of theta waves?
hippocampus is required/involved in its production
What waves have the following characteristics?
<3.5 Hz
100-200uvolts
occur in deep sleep in adults
infants
appear during wakefullness is BAD = sign of organic brain dz
Delta waves
Delta waves does NOT require connection between thalamus and cortex, feedback oscillation within cortex creates waves, taken to indicate that the cortex is no longer?
connected to the thalamus
In general, increased mental/neural activity associated with increased activity on EEG. In infancy there is a fast beta like activity but over the _______ region there is a slow 0.5-2.0Hz activity.
occipital
the activity over the occipital region gradually increase in frequency throughout childhodd and then the adult alpha wave pattern appears during?
adolscence
Frequency of alpha rhythym is decreased by hypoglycemia, low body temp, low adrenal glucocorticoids, and high PaCO2, which all have reduced metabolism in common which leads to reduced?
neuronal activity
Non-REM sleep are grey areas and REM sleep are black bars. NonREM is where most time asleep is spent, there are three stages N1,N2,N3 - N3 is what stage of sleep?
deep sleep
Each stage you see progressive slowing on EEG waves, dreams do occur in nonREM but are generally?
rehashing the days events
REM sleep = rapid eye movement left to right, EEG will see low amplitude and higher frequency waves, associated with what kind of dreams?
Vivid dreams that you remember
NREM majority of sleep eye movements slow, rolling motion eeg gradually slow and dec. amplitude Significance:
intial phase of memory consolidation
REMsleep
aprox every 90mins get longer the later in the sleep
eyes move rapid left to right
eeg decrease amplitude and inc. frequency
significance?
continued consolidation
linking knowledge to previous experience
Sleep: PGD2 in the blood binds DP (receptor) in the leptomeninges, which realses adenosine into the CSF, which goes to the ventrolateral preoptic area (VPO) and does what?
binds adenosine 2a receptors
When adenosine binds 2a receptors in the VPO, it inhibits ascending reticular activiating system (ARAS) inputs to the?
cortex = induces sleep
Along with adenosine in the VPO, IL1b and TNF-a, GHRH activated NFkB which triggers NOS and makes?
NO = sleep
REM sleep is different than the rest. Cholinergic neurons in the lateral pontine tegmentum release Ach in the geniculate body which sends input to the ?
occipital cortex (independent of adenosine loop)
Muscle paralysis in REM sleep is crucial to prevent activating muscle and is mediated by locus ceruleus - inhibitory input to ?
alpha motoneurons (large muscles)
hypothalamus controls arousal as well as sleep induction, lateral hypo is a source of Orexin A and B in the brain which are sent to the tuberomamillary nucleus and activates neurons which release?
histamine from locus ceruleus binds H1 activating LC neurons, which release NE and suppress REM sleep and lead to arousal
children are more in REM and deep sleep, edlerly fewer REM, no deep sleep, more awakening, less total sleep, what is not as strong as it used to be?
circadian rhythym
stages N1, N2, N3 (deep sleep) are characterized by slowing of the EEG, REM is characterized by rapid eye movements and large muscle
paralysis (low amp high freq)
what is seen in stage N2 which are bursts of alpha like activity interrupting the slower EEG of sleep , commonly preceeded by a sharp wave = K complex?
Sleep spindles
by N3 the EMG should be virtually silent (muscles) increasing voltage and slowing frequency w theta and?
delta waves
in REM, EMG is v quiet cause locus ceruleus suppresses, vivid dreams, rapid, low voltage similar to what waves?
beta
If the EEG shows airflow stopping, and movement in the thorax and abdomen are opposite of eachother, what can be expected?
Obstructive sleep apnea
What happens the the EEG / patient completely stops breathing (P flow, abdomen, thorax are all dead lined)?
Central sleep apnea
