week 4 (test 1) Flashcards
(27 cards)
behavioral criteria of sleep
- rapidly reversible state with reduced responsiveness
- increased arousal thresholds
- species-specific posture and place preference
- behavioral rituals (yawning)
- circadian regulation
- homeostasis
hibernation
deepest form of dormacy in mammals lasting for weeks or months
topor
extended daily periods of inactivity and reduced metabolism
functions of sleep
- recovery at cellular, network, and endocrine system levels
- energy conservation
- ecological adaptations
- learning and synaptic plasticity
energy conservation and ecology hypothesis
- animal performance and prey availability peak at specific times of the day
- sleep is an energy saving state
- NREM sleep is a hypo-metabolic state
energy conservation and ecology pros/cons
+
- grounded in natural selection
- modeling approaches
- are energy savings enough
- only valid for NREM
- doesn’t explain selection of REM sleep
learning and brain plasticity hypothesis
- wake is associated with learning, leading to long term potentiation
- process becomes unsustainable energetically and due to space limitations with prolonged wakefulness
- sleep = widespread synaptic depression and synaptic downscaling
- only the most robust connections are left, reducing energy and space for renewed learning
learning and brain plasticity pros
- cognitive effects are obvious even after mild sleep deprivation
- supported by imaging studies
learning and brain plasticity cons
- memory and learning can occur in the absence of sleep
cellular restoration hypothesis
- key components are used up during prolonged wakefulness
- sleep may restore macromolecules
- oxidative stress ensues during wakefulness
- sleep is needed to restore the synthesis of macromolecules and oxidative stress
cellular restoration pros
- changes in gene expression across sleep and wake and after sleep deprivation are consistent across brain regions
- applicable to all species
cellular restoration cons
- changes reported are correlative
- mostly concerns only NREM sleep
7 sleep ages
- pregnancy
- neonatal
- children
- adolescence and young adulthood
- middle age and menopause
- elderly
- disturbance in dementia
sleep during menstrual cycle
- lowest around menses
- increase in spindle activity
- decrease in REM during luteal phase
hormonal influences of sleep
- progesterone high during ovulation, low before period
- pyrogenic -> rem sleep to occur earlier in sleep cycle -> loss of deep sleep -> feelings of depression, anxiety, irritability
pregnancy and sleep
- ~25% report disturbed sleep in 1st trimester
- ~75% report disturbed sleep in 3rd trimester
- 79% of women said sleep was more disturbed during pregnancy than any other time
pregnancy-related sleep disturbances
- disturbed sleep quality
- poor sleep continuity
- short/long sleep duration
- restless leg
- disordered breathing
1st trimester sleep
- difficulty sleeping through night
- nausea
- daytime sleepiness
- increased urination
2nd trimester sleep
- improved sleep and energy
- possible snoring, heartburn, and nightmares
3rd trimester sleep
- difficulty sleeping
- increased urination, snoring, back pain, restless legs
neonatal sleep
- babies do not have stable 24 hour sleep wake rhythm
- generates ~2-6 months
- sleep cycle every 45 minutes
sleep in children
- need as much as possible
- toddlers should spend 40% of time asleep (11-14 hours in 24 hour period)
- preschoolers-11-13 hours
- school aged-9-11 hours
menopause sleep
- hot flashes
- night sweats
- leg cramps ~40%
- depressed mood ~20%
- weight gain
- headaches
- insomnia ~20%
- breathing disorders ~15%
sleep in elderly
- reduced sleep pressure
- increases in stage 1
