sleep (e4) Flashcards
what are our biological rhythms tied to?
the passage of time
what do rhythms help us anticipate?
changes in the environment
circadian rhythms
24 hour biological cycles that influence regulation of sleep and other physical responses
exposure to light readjusts biological clocks by what method
affective activity of the hypothalamus
what part of the brain is a circadian clock
hypothalamus
suprachiasmatic nucleus (SCN)
- influenced by light
- controls release of melatonin in the pineal gland (makes us sleepy)
- light reaches SCN directly in mammals
what controls the release of melatonin
suprachiasmatic nucleus
where is melatonin released
pineal gland
how many stages are there for EEG and sleep?
5
stage 1
5-10 minutes, EEG theta waves
stage 2: brief bursts of higher-frequency brain waves
k-complex and sleep spindles
k-complex
sharp waves, temporal inhibition of neuronal firing, occur after sudden interruption within the sleeper’s environment (noise)
sleep spindles
generated in the thalamus, 500 ms, inhibition, greater number of sleep spindles means more refreshed to perform on a learning task
stages 3 and 4
slow wave sleep, high amplitude but low frequency delta waves, synchronization of low-waves, reduction of sensory input
stage 5: REM sleep
rapid eye movement, high frequency beta waves in some areas, most dreams occur during this stage (can also happen in stages 3/4)
insomnia
chronic problems getting adequate sleep
causes of insomnia
anxiety/tension, depression
narcolepsy
irresistible onsets of sleep during normal waking periods
what causes narcolepsy
lack of hypothalamic cells that produce orexin, huntington’s disease
sleep apnea
frequent, reflexive gasping for air that awakens a person
causes of sleep apnea
obesity, genetics, hormones, old-age deterioration of the brain mechanisms that regulate breathing
night terrors
abrupt awakenings from NREM sleep accompanied by intense autonomic arousal and feelings of panic
nightmares
anxiety-arousing dreams that lead to awakening
REM behavior disorder
people who move around vigorously during REM periods, acting out their dreams
what causes REM behavior disorder
GABA deficiency
sleepwalking
motor cortex is awake
lucid dreaming
monitoring areas are awake (frontal)
sleep terrors
waking up while you still cannot move
fatal familial insomnia
Inherited rare disease, onset occurs when critical amount of PrP is converted to protein PrPres (causes degeneration of thalamus)
consequences of fatal familial insomnia
absence of sleep spindles and k-complexes, deep sleep is reduced, REM sleep can happen during awake state, weight loss, elevated sympathetic activation, hallucinations, epileptic seizures, coma, even death
sleep conserves energy during inefficient times
autonomic nervous system, similar to hibernation
memories that are more important will be ____ during sleep
consolidated better
EEG patterns during sleep resemble those that occur during ______
learning
sleep spindles _____ after new learning
increase in number
what adjustments does the brain make when we learn new things?
strengthening new synapses and weakening or removing old synapses that are no longer used
______ associated with ______ begins when a memory is formed, but is made strong during sleep
reactivation process, consolidation
what is a precursor of melatonin?
serotonin
parasomnias may be related to what
GABA
sleep as a local phenomena
you may have substantial inhibition in one brain area and not so much in another
- sleep walking
- REM behavior
- lucid dreaming
- sleep paralysis
