Sleep Flashcards
What are the behavioural criteria for sleep?
Stereotypic or species-specific posture
Minimal movement
Reduced responsiveness to external stimuli
Reversible with stimulation - unlike coma, anaesthesia or death
Physiological critera for sleep
Electroencephalogramm (EEG)
Electrooculogramm
Electromyogramm
What are the stages of sleep?
AWAKE:
Activity in EEG, EOG, EMG
STAGE 1+2 (NREM)
Non-REM sleep
STAGE 3+4 (NREM)
STAGE 5 (REM)
EOG - tracks muscle movement to do with eye
EEG (tracks rapid activity) - looks quite similar to awake stage
More likely to report dreaming
Heart rate goes up
Slide 10 [pic]
NOTE: go through multiple sleep cycles throughout sleep
Describe a single sleep cycle
Slowing until we reach REM sleep
Slide 11 [pic]
CLOZE
The Reticular Activating System controls consciousness
…
Slide 15 [pic]
Without this, consciousness does not exist
How is the sleep/wake cycle controlled?
Lateral hypothalamus promotes wakefulness (neurotransmitter important for system =orexin/hypocretin)
Ventrolateral preoptic nucleus (anterior hypothalamus) promotes sleep
Slide 17 [pic]
Suprachiasmatic nucleus synchronises sleep with falling light level
NOTE: melatonin can be used for e.g. jet lag = melatonin goes up to make you sleepy
What are the effects of sleep deprivation?
Slide 22
After sleep loss, what happens to the regulation of sleep?
Reduced latency to sleep onset
Increase of slow wave sleep (NREM)
Increase of REM sleep (after selective REM sleep deprivation)
What are the functions of sleep?
restoration and recovery - but active individuals do not sleep more Energy conservation (10% drop in basal metabolic rate) - but lying still is just as effective Predator avoidance - but why is sleep so complex? Specific brain functions - memory consolidation etc etc
When do dreams occur?
Can occur in REM and NREM sleep
Most frequent in REM sleep
More easily recalled in REM sleep
TRUE OR FALSE:
Brain activity in the limbic system is higher than in the frontal lobe during dreams
TRUE
What are the functions of dreams?
Safety valve for antisocial emotions
Disposal of unwanted memories
Memory consolidation
What is insomnia?
Trouble sleeping
High prevalence
Most cases transient
What arethe cuases of chronic insomnia?
Physiological (e.g. sleep apnea, chronic pain) Brain dysfunction (e.g. depression, fatal familial insomnia, night working)
What are the treatments of insomnia?
Sleep hygiene
Hypnotics (most enhance GABAergic circuits)
Sleep CBT
What is sleep hygiene?
Establishing fixed times for going to bed/waking up
Creating a relaxing bedtime routine
Only going to bed when you feel tired
Maintaining a comfortable sleeping environment
Not napping during the day
Avoiding caffeine, nicotine and alcohol late at night
Avoiding eating a heavy meal late at night
Don’t use back-lit devices shortly before going to bed
What is hypersomnia?
Excessive daytime sleepiness
What are the primary causes of hypersomnia?
Narcolepsy
Idiopathic hypersomnolence
Post-traumatic brain injury
What are the secondary causes of hypersomnia?
Slide 33
What is narcolepsy?
Falling asleep repeatedly during the day and disturbed sleep during the night
Cataplexy (sudden, brief loss of voluntary muscle tone, often triggered by strong emotions e.g. laughter)
Dysfunction of control of REM sleep
Orexin/hypocretin deficiency
What are the effects of shift work on sleep
Night working = physiological processes become desynchronised
Can lead to sleep disorders, fatigue and an increased risk for some conditions (e.g. obesity, diabetes and cancer)
What is consciousness?
The subject experience of the mind and the world around us
That there is “something it is like” to be in the state of the subjective or first-person point of view
The state of being aware of and responsive to one’s surroundings
