9 Sleep Flashcards
Q: Why is sleep vital?
A: Sleep is vital for normal functioning, health, well-being, and memory.
Q: What happens if we are deprived of sleep?
A: We will make up part of the lost sleep, indicating it is regulated.
Q: How is sleep research typically conducted?
A: In a sleep lab, where researchers monitor EEG (brain activity), EMG (muscle activity), and EOG (eye movements).
Q: What are the two basic patterns of brain activity during wakefulness?
A: Alpha waves when resting (8-12Hz, regular, medium frequency) and beta waves when alert (13-30Hz, irregular, mostly low amplitude).
Q: How many stages of sleep are there in one cycle, and how many cycles occur per night?
A: There are 5 stages per cycle, and we cycle through them 4-5 times a night.
Q: What is the brain activity in Stage 1 of sleep?
Q: How long does Stage 1 of sleep last and what characterizes it?
A: Theta activity (3.5-7.5Hz), with neurons in the neocortex firing more synchronously.
A: It lasts about 10 minutes and is a transition between wakefulness and sleep.
Q: What are sleep spindles and K complexes, and in which stage do they occur?
A: Sleep spindles are short bursts of waves (12-14Hz), and K complexes are sudden sharp waveforms; both occur in Stage 2.
Q: What is the significance of K complexes and increased sleep spindles?
A: K complexes are associated with memory consolidation, and increased sleep spindles are associated with higher scores on intelligence tests.
Q: What brain activity is observed in Stage 3 of sleep?
A: High amplitude delta waves (<3.5Hz), with Stage 3 having 30-50% delta activity.
Q: What distinguishes Stage 3 from Stage 4 of sleep?
A: Stage 3 has 30-50% delta activity, while Stage 4 has more than 50% delta activity.
Q: What characterizes REM sleep?
A: EEG desynchrony with rapid, irregular waves, dreaming, loss of muscle tone (paralysis), increased cerebral blood flow and O2 consumption, and cessation of mechanisms regulating body temperature.
Q: What happens if a person is woken during REM sleep?
A: They are usually attentive and alert.
Q: What neurotransmitter is associated with high activity in the hippocampus and neocortex and promotes wakefulness when activated in the basal forebrain?
A: Acetylcholine (ACh).
Q: How does norepinephrine contribute to arousal?
A: Activity of noradrenergic locus coeruleus (LC) neurons increases vigilance, with increased activity during wakefulness and moment-to-moment activity related to performance on vigilance tasks.
Q: What role does serotonin play in arousal and sleep?
A: Serotonin stimulates locomotion and cortical arousal, with serotonergic neurons being most active during waking, steadily declining during sleep, almost reaching zero during REM sleep, and becoming very active after REM sleep.
Q: Where are histamine neurons located, and how do they affect sleep and waking?
A: Histamine neurons are located in the hypothalamus. Drugs that prevent histamine synthesis or block histamine receptors decrease waking and increase sleep, with high activity during waking and low activity during slow-wave and REM sleep.
Q: What is the role of orexin in arousal?
A: Orexin has an excitatory effect on the cerebral cortex and regions involved in arousal, with neurons located in the hypothalamus. Activating these neurons can awaken mice from REM and non-REM sleep, and in rats, they fire fastest during active waking, particularly when exploring.
Q: What are the three factors that control slow-wave sleep?
A: Homeostatic, allostatic, and circadian factors.
Q: How does adenosine affect sleep?
A: The presence or absence of adenosine is a homeostatic factor that influences sleep, with its build-up promoting sleep.
