Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
49 Cards in this Set
- Front
- Back
|
EEG |
electroencephalogram - electrodes on scalp to record electrical activity of brain |
|
|
EMG |
electromyogram Electrodes on chin to record muscle activity |
|
|
EOG |
Electrooculogram Electrodes around eye to monitor eye movements |
|
|
EEG: Awake |
Alpha and Beta waves |
|
|
Alpha waves |
Medium Amplitude, 8-12Hz Indicate resting state - not engaged in strenous mental activity |
|
|
Beta Waves |
Irregular Amplitude 13-30Hz Indicate general arousal Desynchronous activity: different neural circuits actively processing information at the same time |
|
|
Stage 1 Sleep |
Transition between wakefulness and sleep Firing of neurons in neocortex more synchronized Shows theta activity Eyelids flutter and eyes roll behind closed eyelids Muscle activity: slows down + twitches |
|
|
Theta activity |
3.5-7.5Hz with higher amplitude |
|
|
Stage 2 Sleep |
Starts after about 10min of stage 1 Body Temp and Respiration decrease - Sleep spindles and K complexes - Theta activity
|
|
|
Sleep spindles |
Short bursts of activity (12-14Hz) -> 2-5/min Occur during stages 1-4 Thought to be important for consolidation of memories & staying asleep # decreases with age |
|
|
K complexes |
Only Stage 2 Sudden sharp waveforms 1/min (occur spontaneously) Can be triggered by unexpected noise # increases with age Not primary function but thought to keep person asleep Forerunner of delta waves |
|
|
Slow-wave sleep |
Stages 3 & 4 (4 -> deep sleep, cannot be awakened by noise & cerebral blood flow and O2 consumption decrease) Delta waves - Stage 4 has higher % of delta waves (>50% vs 20-50%) Biphasic oscillations of neocortical neurons (periods of high and low firing rates) - <1Hz frequency of oscillations 1. Down state: neocortex inhibited and resting 2. Upstate: Neurons briefly fire at high rate |
|
|
Delta waves |
<3.5Hz High amplitude Found in slow-wave sleep: More frequent in stage 4 Indicate that brain is resting |
|
|
REM sleep |
Occur after 90min (45min after stage 4). Lasts 20-30min Rapid eye movements React to meaningful stimuli - wake up alet and attentive + report dreaming Increased genital activity (erections/vaginal secretions) Desynchronous activity: mental processing=> Theta and Beta activity Cerebral blood flow and O2 consumption increase EMG: silent - no muscle tone. Occasional twitch
|
|
|
Sleep cycle |
90min + 20-30min REM Early night: Non-REM dominant Late night: REM dominant + More and More stage 2, and less slow-wave sleep i.e become more and more synchronized until REM where desynchronized |
|
|
Cerebral blood flow during sleep |
High to visual association cortex (hallucinations in dreams) Low to V1 and PFC (dreams are temporarily unorganized - similar to PFC damage -> prob with sequences of events) - sometimes people fill in gaps and are convinced of it |
|
|
Dreams |
Story-like in REM Some in stage 4 - nightmares Don't remember emotions in dreams |
|
|
Length of sleep |
Related to vulnerability Ex. Lions after kill may sleep for 3 days ex. horse/deer/zebra - little sleep, need to graze Marine mammals: complex sleep mechanisms (bottle nosed dolphins: 2 hemipheres sleep independently to remain behaviorally alert) |
|
|
Effect of sleep deprivation |
Affects cognitive and not physical skills Lost sleep will never be regained but you recuperate important stages = rebound phenomenon (make up higher % of REM and slow wave relative to stages 1&2) |
|
|
What indicates that the brain is resting? |
Delta waves and low phgy activity Need to rest to relieve oxidative stress (free oxygen radicals that accumulate due to high metabolic rate of wakefulness) When awake: imbalance between production of O radicals and the ability to detoxify them -> oxidative stress |
|
|
Yoked control procedure |
Both animals receive same amount of treatment at same time (same amount of exercise) But exp. rat more sleep deprived than yoked rat
Exp rat: loses/gains weight, uncoordinated, high level of stress. Eventually dies. Yoked rat: good health |
|
|
Functions of REM sleep |
Highest proportion in active dev. Newborns: 70% REM Adult: 15% REM Consolidates memories -> needed for non-declarative memory & learning
Rats: facilitates learning: -% increases when rate of learning is best -decreases to baseline levels once learnt REM sleep deprived: performs poorly in maze task |
|
|
Rebound phenomenon |
Increased f or intensity of a phenomenon after it has been temporarily suppresed |
|
|
Functions of Slow-wave sleep |
Declarative memories - rehearsing newly learned info Hippocampus active (not during REM) Brain is resting and restoring effect of oxidative stress (delta waves) |
|
|
Insomnia |
Defined relative to particular person's need for sleep Symptom characteized by persistent difficulty falling asleep despite opportunity. Causes: - Psychoactive drugs/stimulants - Hormonal shifts (preceding menstruation/during menopause) - Psychological problems (fear/stress/anxiety) - Shifts in circadian rhythms - Abuse of sleeping meds - producing drug-dependent insomnia |
|
|
Sleep apnea |
Insomnia caused by inability to sleep and breath at the same time Usually caused by obstruction in airway -> Chemoreceptors sense level of CO2 -> snore or wake up gasping for air -> Oxygen level in blood normalizes and cycle begins again |
|
|
Narcolepsy |
Neurological genetic disorder characterized by sleep at inappropriate times Symptoms: - Sleep attack - Sleep paralysis - Cataplexy
|
|
|
Sleep attack |
Overwhelming urge to sleep During mundane activities Multiple times a day for few minutes |
|
|
Sleep paralysis |
Invasion of REM during waking hours - unable to move before onset of sleep and upon waking Hypnagogic hallucinations (often alarming & terrifying) |
|
|
Cataplexy |
Precipitated by strong emotional reactions/sudden physical effort Sudden paralysis of REM During day |
|
|
Causes of narcolepsy |
Mice: Mutation of Hypocretin 2 gene (NT) -chr6 or Orexin B Lots of env effects as well ->Eventual death of neurons in adulthood and show narcolepsy symptoms
Humans: usually born with the neurons but immune system attacks them in adolescence
Same genetic mutation causes narcolepsy in dogs |
|
|
REM Sleep Behavior disorder |
Act out dreams (not sleepwalking) No paralysis |
|
|
Problems with Slow-wave sleep |
Stage 4 symptoms: - Sleep walking (somnanbulism) - Nocturnal enuresis - Pavus nocturnus: Night terrors (screams, trembling, rapid pulse - often no memory of cause) |
|
|
Sleep related eating disorder |
During sleep walking Leaves bed and eats food Usually no memory of episode
Treated with dopaminergic agonists, topiramate (anti-seizure med)
Can be provoked by zolpidem (benzodiazepine for insomnia) |
|
|
Adenosine |
Nucleoside neuromodulator Accumulates extracellularly during wakefulness due to depletion of glycoge stores in astrocytes (due to high metabolic activity) Primary role in initiation of sleep: inhibitor of neural activity When brain rests: restocks glycogen level
(chemical must be produced in brain, not circulated throughout body + must be 2 chemicals - one for REM) |
|
|
Caffeine |
Blocks adenosine receptors |
|
|
Fatal familial insomnia |
Progressive insomnia resulting in damage to thalamus First: # sleep spindles and K complexes reduce Then: Disappearance of slow-wave sleep Only short bouts of REM left (with no paralysis)
Causes: deficits in attention/memory, dreamlike confused state, loss of control of autonomic & endocrine systems, increased body T and insomnia |
|
|
How to treat Narcolepsy |
Modafinil (stimulant drug) increases Fos in orexigenic neurons but most act elswhere because patients dont have these neurons
Sleep attacks can be treated with stimulants like methyphenidates ex. ritalin a catecholamine agonist |
|
|
alpha-synucleiopathies |
REM sleep disorders - usually degenerative because of inclusion of slpha-synuclein protein in degenerating neurons These can be caused by destruction of brain circuits in BS that control REM paralysis |
|
|
Clonozopam |
Benzodiazepine tranquilizer - treatment for REM sleep disorder |
|
|
Adenosine deaminase |
Breaks down adenosine Variability causes variability in people's need for sleep G/A allele - slower break down need more SWS than people with G/G allele |
|
|
Location of Locus Coeruleus |
Dorsal pons |
|
|
Amphetamines |
Catecholamine agonist Increases arousal through noradrenergic system of LCL |
|
|
Location of Raphe Nuclei |
Medullary and pontine regions of Reticular formation |
|
|
PCPA |
decreases production of 5Ht and reduces arousal |
|
|
Adenosine Receptors |
found in VlPOA and various other regions of brain like Lat hypothalamus |
|
|
Where is SLD |
Ventral to LC In dorsal pons |
|
|
Where is vlPAG |
Dorsal midbrain |
|
|
REM sleep components? - What causes rapid eye movements - cortical desynchrony? - penile erections? - Paralysis |
- SLD --> Dorsal pons --> Tectum - SLD --> Medial pontine reticular formation --> BF (ACh) - SLD --> dorsal pons (ACh) and lateral POA - SLD --> inhibitory interneurons in SC and BS |
