sleep and wake

Question 1

circadian (daily) rhythm

Answer 1

a repeating cycle for about 24 hours

Question 2

ultradian cycle

Answer 2

a cycle that occurs several times in a single day,

lasts approx. every 90-120 min in a 24 hour day

Question 3

free-running circadian rhythm

Answer 3

a rhythm that is not synchronized to environmental time cues (last approx. 24,2h 24,9h)

Question 4

zeitgeber

Answer 4

an external cue for setting biological rhythms

-light is the most important one for humans

Question 5

entrainment

Answer 5

the resetting of internal biological clocks to the 24h cycle of the earth’s rotation

Question 6

shift maladaptation syndrome

Answer 6

a condition resulting in health, personality, mood and interpersonal problems resulting from sleep distruption due to shift work

Question 7

jet leg

Answer 7

fatigue, irritability, sleepeness resulting from travel across time zones; conflict between internal clocks and external zeitgebers

Question 8

suprachiasmatic nucles (SCN)

Answer 8

an area of the hypothalamus located above the optic chiasm, responsible for maintaining circadian rhythms

Question 9

intrinsically photosensitive retinal ganglion cells (ipRGC)

Answer 9

retinal cells that do not process information about visual images but rather provide light information to the suprachiasmatic nucleus

Question 10

retinohypothalamic pathaway

Answer 10

a pathway leading from the retina of the eye to the hypothalamus; provides light information necessary for the maintanance of circadian rhythms

Question 11

melanopsin

Answer 11

a photopigment used by ipRGCs

Question 12

melatonin

Answer 12

an indoleamine secreted by the pineal gland that participates in the regulation of circadian rhythms

Question 13

per, tim, clock genes and proteins in fruit flies

Answer 13

genes and proteins in fruit flies that are involved in several circadian rhythms.
Per and tim inhibit the clock, but clock promotes production of more per and tim

Question 14

cortisol

Answer 14

a hormone released by the adrenal glands that promotes arousal

Question 15

major depressive disorder (MDD) with seasonal pattern

Answer 15

a type of depression that results from insufficient amount of daylight during the winter months, possible reasons:
serotonin levels drop in winter, disruptions of melatonin caused by uneven patterns of daily light, disruption of melanopsin

Question 16

desynchronous

Answer 16

brain activity associated with independent action of many neurons and alertness

Question 17

synchronous

Answer 17

brain activity associated with neurons firing in unision and deep sleep

Question 18

beta wave

Answer 18

a brain waveform having 14-30 cycles /s associated with having high level of alertness during wakefulness

Question 19

alpha wave

Answer 19

a brain waveform having 8-13 cycles per second associated with less alertness and more relaxation than beta waves during wakefulness

Question 20

gamma band activity

Answer 20

a brain waveform having more than 30 c/s associated with processing of sensory input

Question 21

theta wave

Answer 21

a brain waveform having 4-7 c/s find primarily in lighter stages of REM sleep

Question 22

rapid eye movement (REM) sleep

Answer 22

a period of sleep characterized by desynchronous brain activity, muscle paralysis, eye movement, story-like dream behavior

Question 23

n-REM sleep

Answer 23

a period of sleep characterized by slow synchronous brain activity, reductions in heart rate and muscle relaxation

Question 24

myoclonia

Answer 24

a muscle jerk occuring in early stages of sleep; often accompanied by a brief visual image

Question 25

sleep spindle

Answer 25

a short burst of 12 to 14 cycles per second waves observed during n-REM sleep; generating by interaction by the thamalus and the cortex; prominent in stage 2, but can occur in other stages of n-REM

Question 26

K- complexes

Answer 26

a brief burst of brain activity consisting of single delta waves occuring during stage 2 of n-REm sleep

Question 27

delta wave

Answer 27

a brain waveform having 1-4 c/s that occur during stages 3 and 4 of non-REM sleep

Question 28

paradoxical sleep

Answer 28

1sr period of REM sleep (after 90 min of n-REM)

paradoxical cause of brain activity resembling waking with external appearance of deep sleep

Question 29

brain networks that control waking and sleep

Answer 29

circuits connecting the brainstem, hypothalamus, basal forebrain

Question 30

networks managing waking

Answer 30

ventral pathaway (from the medulla to the posterior hypothalamus onto the basal forebrain) + dorsal pathaway that projects to a group of cells the reticular formation - cholinergic mesopontine nuclei (the junction of the pons and midbrain), + locus coeruleus (more active when person is alert cause it is the source of most of norepinephrine) + anterior raphe nuclei (active during wakefulness and communicates with preoptic area and SCN) + DMN

Question 31

cholinergic mesopontine nuclei

Answer 31

group of cells located at the border of the pons and midbrain (meso-midbrain, pontine-pons) that use Ach as their major neurotransmitter and participate in the maintanace of waking

Question 32

Default mode network (DMN)

Answer 32

a circuit that is active during periods of unfocused thought; consists of medial prefrontal, medial parietal, lateral parietal and lateral temporal cortex; activity is assoicated with daydreaming and decreases when a person engages in a conscious task

Question 33

n-REM sleep networks

Answer 33

preoptic area (POA) -receives info from the anterior raphe nuclei, and forms inhibitory feedback loops with waking pathaways; activation of POA will lead to inhibition in circuits promoting waking; sleep occurs

Question 34

POA cells

Answer 34

activation produces sleep; called n-REM on cells bcs electrical stimulation produces immediate NREM sleep, and lesions insomnia

Question 35

sleep dept

Answer 35

homeostatic control of sleep, in which sleep promotion is related to the preceding duration and intensity of wakefulness

Question 36

PGO wave

Answer 36

an electrical waveform observed during REM, originating in the pons and traveling to the thalamus and occipital lobe. Each PGO wave is associated with an eye movement; pgo wave-reticular formation-lateral geniculate nucleus of the thalamus