Sleep Flashcards
(24 cards)
What brain regions are associated with wakefulness and what do they release?
Locus coeruleus - norepinephrine
dorse raphe nucleus - serotonin
pons - acetylcholine
lateral hypothalamus - orexin (neuropeptide)
tuberomammillary nucleus - histamine
What brain regions are associated with sleep and what do they release?
Ventrolateral preoptic area (hypothalamus ) - GABA
Explain the flip flop circuit.
More GABA from VLPO released onto wake neurons during sleep. More GABA from arousal neurons released onto VLPO during wake.
What order are EEG waves in? Which is slowest? Which is fastest?
delta, theta, alpha, beta, gamma
slowest to fastest
What EEG waves are associated with high activity?
beta, gamma
What EEG waves are associated with being more relaxed and awake?
alpha
What EEG waves are associated with stage 1 sleep?
theta waves
sleep in general will have greater amplitude and less frequency in brain waves
What EEG waves are associated with stage 2 sleep?
appearance of spindle complexes and k complexes
What EEG waves are associated with stage 3?
delta waves: greatest amplitude, lowest frequency
What EEG waves are associated with REM sleep?
beta waves; high frequencies, low amplitude
What are characteristics of REM sleep?
- Heart rate and breathing increase
- Dreaming occurs (everyone dreams)
- “Paradoxical sleep” - brain wavelengths resemble wakeful state
- Major muscle groups are paralyzed
What regions are less active during non-REM sleep compared to being awake?
caudate nucleus, thalamus, hypothalamus, pons
What is Polysomnography?
Measures multiple physiological parameters to diagnose sleep disorders and study sleep
what regions dictates circadian rhythm?
suprachiasmatic nucleus
What are examples of polysomnography?
EEG – brain activity during sleep stages
EOG – ocular muscles; eye movement
EMG – skeletal muscle activity
What role does adenosine play in sleep?
- Adenosine – somnogen (promotes sleep); acts via adenosine receptors
- Caffeine antagonizes (inhibits) adenosine receptors
- When ATP is broken down, adenosine is left and accumulates during the day in the synaptic cleft
What purpose does orexin serve in sleep and wakefulness?
promotes sleep and muscle tone
What does sublaterdorsal nucleus (SLD) do?
promotes muscle atonia
SLD - located in pons
needs to be inhibited in the wake state?
How does orexin promote wakefulness?
It will activate or promote activation of Tuberomammillary nucleus, Locus Coerulus, basal forebrain, dorsal raphe, pedunculopontine and laterodorsal tegmental nuclei.
How does orexin maintain muscle tone during wake?
It activates neurons that will inhibit SLD being centrolateral periaqueductal grey and lateral pontine tegmentum, dorsal raphe and locus coeruleus.
What does benzodiazepenes and Z-drugs do?
They treat insomnia by acting as angonist that prolong arousal network inhibition (promoting sleep).
What deficiency do people narcolespy have? what does it cause?
deficiency in orexin –> insomnia and muscle atonia
What happens when people with narcolespy laugh?
Sudden emotion activated (amygdala) –> inhibit inhibitory neurons of SLD –> cataplexy
cataplexy - sudden loss of muscle tone
what are the brain regions associated with dreaming?
- cingulate gyrus
- striatum
- amygdala
- hippocampus
- parietal association cortex
