Sleep Flashcards

Question

Intrinsically photosensitive retinal ganglion cells (ipRGCs)

Answer 1

Can receive input from rods and cones Other ganglion cells can send signals to SCN Both rods and cones and ipRGCs contribute to circadian photoentrainment M1 cells: non-image forming, ambient light info/how light or dark it is (influences Per and Cry proteins transcription) Damage before SCN = light doesn't work as zeitgerber

Answer 2

Endocrine gland located posterior to thalamus Releases melatonin, found in almost all animals, plants, and bacteria Released mostly at night, increases sleepiness in humans In nocturnal animals it increases wakefulness Pineal gland tumour can cause people to stay awake for days at a time Helps control onset of puberty and bodily adjustments to changes of season (e.g. hibernation)

Answer 3

State the brain actively produces Characterized by decreased activity and decreased response to stimuli

Answer 4

Extended period of unconsciousness caused by head trauma, stroke, or disease Low level of brain activity Little or no response to stimuli People in a coma either die or begin to recover within a few weeks

Answer 5

Alternates between periods of sleep and moderate arousal Even during aroused state person shows no awareness of surroundings and no purposeful behaviour Breathing is more regular Painful stimulus produces at least the automatic responses of increased heart rate, breathing, and sweating Can last for months or years

Answer 6

Brief periods of purposeful actions and limited amount of speech comprehension Can last for months or years

Answer 7

Condition with no sign of brain activity and no response to any stimulus Ensure this is constant for 24 hours before pronouncing brain death Ethical to remove life support

Answer 8

Records an average of the electrical potentials of cells and fibers in brain areas nearest to electrodes Monitor brain activity during sleep

Answer 9

Muscular measurement

Answer 10

Eye tracking

Answer 11

Measure heart rate

Answer 12

Combining different metrics for multimodal analysis

Answer 13

Characteristic of relaxation

Answer 14

8-13 cycles per second

Answer 15

Eyes are stationary

Answer 16

4-8 cycles per second EEG shows irregular, jagged, low voltage waves Brain activity is less than in relaxed wakefulness, higher than other sleep stages

Answer 17

4-8 cycles per second 0.5-2 second spindles at 12 and 14 CPS thalamus Anterior cingulate cortex K-complexes Sleep spindles

Answer 18

Sharp wave associated with a temporary inhibition of neuronal firing (amplitude spike)

Answer 19

Burst of 12-14 Hz waves for at least half a second Result from oscillating interactions between cells in thalamus and cortex Increase in number after learning Number of sleep spindles correlates positively with improvements in certain types of memory Consistent activity from one night to another Can predict nonverbal tests of IQ

Answer 20

Slow wave sleep Begin to see slow wave/delta wave pattern Approaching less than 4.5 cycles per second Heart, breathing, and brain activity decrease Slow, large amplitude waves become more common Fewer slow waves than stage 4 Slow waves indicate neuronal activity is highly synchronized Occurs mostly earlier in sleep period

Answer 21

Low amplitude high frequency waves Increases later in the sleep period

Answer 22

Another name for REM sleep Combines characteristics of both wakefulness (increased brain activity) and sleep (low levels of body activity)

Answer 23

Trying to test learning abilities of cats after removal of cerebral cortex Realized that certain areas of brain activity was high but neck was relaxed

Answer 24

Discovered that people move their eyes during sleep Rapid eye movement (REM) sleep: synonymous with paradoxical sleep

Answer 25

Irregular, low voltage fast waves that indicate increased neuronal activity Postural muscles of body are more relaxed than during other stages Associated with erections/vaguinal moistening Heart rate, blood pressure, breathing rate, facial twitches fluctuate Increased activity in ventral visual association areas Reduced activation in frontal area & primary visual cortex Combines aspects of deep and light sleep

Answer 26

Each cycle lasts about 90 mins Stage 1 - stage 2 - slow wave - stage 2 - REM Slow wave sleep predominate early in the night REM occupies increasing percentage over time Sleep stage patterns varies with age, health, and other factors

Answer 27

People report dreams more often during REM Dreams during REM more likely to include visual imagery and complicated plots

Answer 28

Structure that extends from medulla into forebrain Cut through midbrain damages reticular formation Some neurons in reticular formation have axons ascending into brain, some have axons descending into spinal cord Those with axons descending into spinal cord form part of the medial tract of motor control Neurons with ascending axons are suited to regulate arousal

Answer 29

Part of reticular formation that contributes to cortical arousal Neurons receive input from many sensory systems and generate activity of their own, varying with circadian rhythm Axons extend into forebrain Some axons release GABA (Inhibits/interrupts behaviour, Promotes slow wave sleep) Some axons release acetylcholine, glutamate, dopamine (Produce arousal in hypothalamus, thalamus, and basal forebrain, produce wakefulness by regulating levels of potassium and other ions that produce constant state of arousal)

Answer 30

Small structure in the pons Usually inactive especially during sleep Emits bursts of impulses in response to meaningful events, especially ones that produce emotional arousal Axons release norepinephrine throughout cortex Small area with big influence Output from locus coeruleus is called a ‘gain’

Answer 31

Increases activity of most active neurons Decreases activity of less active neurons Produces enhanced attention to important information and enhanced memory

Answer 32

Intermingled neurons that produce different effects One axon pathway releases histamine (excitatory neurotransmitter, enhances arousal and alertness) Pathway from lateral & posterior nuclei of hypothalamus release peptide neurotransmitter called orexin or hypocretin (enhance wakefulness and activity, for staying awake)

Answer 33

Depends on decreased sensory input to cerebral cortex (inhibition - GABA) Neurons in thalamus become hyperpolarized, decreasing readiness to respond to stimuli Moderate amount of responsiveness remains (e.g. wake up to loud sounds)

Answer 34

Sleepwalking: motor cortex and some other ares remain awake Lucid dreaming: activity in frontal and temporal cortex Sleep paralysis: pons remains in REM to prevent movement

Answer 35

Difficult to inject chemicals without waking Insert cannula in arm and sleep with heads attached (prevent movement) Stay awake one night prior to increase sleep during night 2

Answer 36

Increased activity: Pons, limbic system, parts of temporal and parietal cortex Decreased activity: Primary visual cortex, motor cortex, dorsolateral prefrontal cortex

Answer 37

Distinctive pattern of high amplitude electrical potentials Detected first in pons, then in lateral geniculate nucleus, then occipital cortex

Answer 38

Stimulates acetylcholine synapses Moves sleeper into REM when injected

Answer 39

Serotonin & norepinephrine

Answer 40

Dorsolateral prefrontal cortex (DLPFC): related to attention control Attention lapses increases when sleep debt increases

Answer 41

Depleted sleep decreases proportion of content remembered Buildup of adenosine with sleep deprivation which suppresses learning mechanisms in hippocampus REM disruptions particularly detrimental

Answer 42

Cognitive deficits resulting from sleep deprivation create real life consequences (e.g. more car accidents) More sleep = less physical injury incidents

Answer 43

Sleep loss triggers changes in negative emotional processing (irritability, emotional volatility, anxiety and aggression, and suicidal ideation, attempts, contemplation) Sleep deprived people show greater activity in amygdala Decreased connectivity between amygdala and prefrontal cortex (more emotionally reactive)

Answer 44

Restoration Clearance Memory

Answer 45

To restore and replenish various substances needed for proper brain health and function Adenosine triphosphate (ATP) a key energy source for neural function spikes after onset of sleep

Answer 46

Clearing various undesirable substances that have built up during wakefulness (e.g. adenosine or molecules that impair functioning) Movement of substances through the interstitial space more efficient while rats are asleep (interstitial space expands during sleep) Rate of Beta-amyloid clearance greater during sleep

Answer 47

Studying before bed and testing the following day at 10am and 10pm increased retention Sleeping between study and test sessions improves performance in test sessions

Answer 48

Hard for body to make sense of information when dreaming Activation synthesis model - due to deactivation of prefrontal cortex (see note)

Answer 49

Hybrid state Reduction in frontal processing and visual cortex as compared to when awake Slightly more activation in frontal compared to REM

Answer 50

Inadequate sleep Impairs memory, attention, cognition Magnifies unpleasant emotional reactions Increases risk of depression

Answer 51

Difficulty getting to sleep

Answer 52

Difficulty staying asleep

Answer 53

Noise, light, uncomfortable temperatures, stress, pain, diet, medications Late night exercise or eating Irregular bedtime, late night media use Epilepsy, Parkinson’s disease, brain tumours, depression, anxiety, or other neurological or psychiatric conditions Use of sleeping pills (inability to sleep without them)

Answer 54

State in which muscle immobilization, normally characteristic of REM sleep, occurs even though the person is not longer actually sleeping

Answer 55

When going to sleep

Answer 56

When waking up

Answer 57

Impaired ability to breathe while sleeping Breathless periods of a minute or so, awaken gasping for air May not remember awakenings Increases risk of stroke, heart problems, and other disorders Multiple brain areas that have lost neurons Deficiencies of learning, reasoning, attention, impulse control

Answer 58

Genetics, hormones, old age deterioration of brain mechanisms that regulate breathing Obese men have narrow airways and have to breathe faster when awake, can’t maintain this rhythm at night

Answer 59

Lose weight Avoid alcohol and tranquilizers Mask that covers nose and delivers air under enough pressure to keep breathing passages open (continuous positive airway pressure (CPAP) machine Surgery on jaw or breathing spaces only sometimes helps

Answer 60

Attacks of sleepiness during the day Occasional cataplexy Sleep paralysis Hypnagogic hallucinations

Answer 61

Attack of muscle weakness while the person remains awake Often triggered by strong emotions (e.g. anger, excitement)

Answer 62

Flu (H1N1 flu virus) Lack hypothalamic cells that produce and release orexin Could be due to an autoimmune reaction Deficiency of orexin may be a cause

Answer 63

Stimulants that increase dopamine and norepinephrine

Answer 64

Repeated involuntary movement of the legs and sometimes arm during sleep Mostly middle aged people and older Legs kick once every 20-30 seconds, mostly during non REM sleep

Answer 65

Move around vigorously during REM periods Appear to be acting out their dreams Frequently dream about defending themselves from an attack Often injure themselves or damage property Could be due to inadequate inhibitory transmission

Answer 66

Experiences of intense anxiety from which a person awakens screaming in terror Usually during non REM sleep More common in children Dream content is either simple (e.g. one image) or entirely lacking

Answer 67

Runs in families, mostly occurs in children More common when people are sleep deprived or under unusual stress Most common during slow wave sleep Actions are poorly planned and not remembered

Answer 68

Sleeping people engage in sexual behaviour (with partner or by masturbation) Don’t remember Many people with sexsomnia were sleepwalkers as children