Sleep and Arousal

What controls circadian rhythms in the body?

The suprachiasmatic nucleus (SCN) regulates circadian rhythms.

How does light affect melatonin production?

Light stimulates the SCN, resulting in decreased melatonin production by the pineal gland.

What is the relationship between chronotype and age?

Chronotype tends to alter with age, where younger individuals are more likely to be night owls and older individuals are more likely to be morning larks.

What is one primary reason we sleep according to the Restorative Theory?

Sleep allows for the repair and regeneration of the body.

What is synaptic pruning?

Synaptic pruning is the process during sleep where certain synaptic connections are strengthened and others are weakened.

What is the role of slow-wave sleep (SWS)?

SWS is essential for recuperation and recovery, and about 50-70% of growth hormone is released during this stage.

What is Fatal Familial Insomnia?

A hereditary disease where individuals cannot sleep, leading to severe brain dysfunction and death within 6 months.

What are the functions of REM sleep?

REM sleep is important for dreaming, brain development, learning, and consolidation of nondeclarative memory.

What happens during REM sleep rebound?

When sleep deprived, individuals experience increased amounts of REM sleep to compensate.

What is the relationship between sleep deprivation and cognitive performance?

Being sleep deprived can impair cognitive performance to levels equivalent to certain blood alcohol concentrations.

How does REM sleep change with age?

Infants and toddlers experience more REM sleep which is crucial for brain development, while the amount of REM decreases as we age.

How do different species compare in terms of sleep hours?

There are large differences in sleep duration across species, such as bats sleeping about 19.9 hours and horses about 2.9 hours.

What does an electroencephalogram (EEG) measure?

An EEG measures the electrical activity of the brain and identifies different patterns during sleep stages.

What characterizes stage 2 sleep?

Stage 2 sleep is characterized by feeling like you’ve been asleep but also feeling like you are on the edge of wakefulness.

What are sleep spindles and K complexes?

Sleep spindles are short bursts of brain activity, while K complexes are sudden sharp waveforms in response to stimuli.

What neurotransmitter is primarily associated with wakefulness?

A higher level of norepinephrine during wakefulness aids attention and vigilance.

What is the primary inhibitory neurotransmitter that promotes sleep?

GABA is the major inhibitory neurotransmitter that helps promote sleep.

How does the Sleep/Waking Flip Flop work?

The flip-flop mechanism controls the transition between wakefulness and sleep states by either activating arousal systems or the ventrolateral preoptic area (vlPOA).

What symptoms are associated with narcolepsy?

Symptoms include sleep attacks, cataplexy, sleep paralysis, and hypnagogic/hypnopompic hallucinations.

How is narcolepsy treated?

Treatment includes stimulants like Ritalin and Modafinil, as well as SSRIs and SNRIs to reduce REM sleep components.

What occurs in the brain during REM sleep?

During REM sleep, brain activity increases, and this is where dreaming primarily takes place.

What role do acetylcholine levels play during sleep?

Acetylcholine levels are high during wakefulness and REM sleep, playing a role in cortical arousal.

What changes occur in metabolism during sleep?

Metabolism rate decreases by about 10% during sleep, resulting in lower energy expenditure.

Why is sleep essential for memory consolidation?

Sleep allows for the consolidation of declarative and nondeclarative memories, facilitating learning.

How are muscle tensions measured during sleep?

Muscle tensions are measured using an electromyogram (EMG), particularly in facial and neck muscles.

What is the primary function of the suprachiasmatic nucleus?

The SCN serves as the master clock for regulating circadian rhythms and sleep patterns.

What type of sleep is disrupted in Fatal Familial Insomnia?

Slow-wave sleep (SWS) is disrupted, leading to severe consequences.

What is implicit memory?

Implicit memory involves skills and tasks that you cannot verbally describe, like riding a bike.

What is the effect of an increase in adenosine levels?

Adenosine levels rise during the day with increased activity and peak when falling asleep, promoting sleep.

What is the typical percentage of time spent in REM sleep?

REM sleep usually accounts for about 20-25% of total sleep time.

What does the Energy Conservation Theory suggest about sleep?

It suggests that sleep serves as a period for conserving energy after survival activities like hunting and gathering.

What type of sleep do humans naturally gravitate towards during the dark?

Humans tend to sleep during the dark hours largely due to the limitations of visibility and vulnerability to dangers.

What is the main criterion for sleep diagnosis?

Persistent sleep disturbances affecting daytime functioning can serve as indicators for diagnosing sleep disorders.

What genetic factor can lead to narcolepsy?

A mutation in the orexin B receptor is associated with narcolepsy.

What is the potential outcome of chronic lack of slow-wave sleep?

Chronic lack of SWS can be correlated with various disorders including cardiovascular disease and Alzheimer's.

What role does serotonin play during sleep?

Serotonin levels are high during wakefulness and decrease towards REM, influencing various behaviors.

What is the importance of slow-wave sleep for hormones?

A significant release of growth hormones occurs during slow-wave sleep, crucial for physical recovery.

What are hypnagogic and hypnopompic hallucinations?

They are hallucinations that occur while falling asleep (hypnagogic) or waking up (hypnopompic).