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Flashcards in 37-Sleep Deck (34)
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1

defining criteria of sleep (x4)

- reduced motor activity
- reduced response to stimulation
- stereotypic postures (lying down in humans)
- relatively easy reversibility (as opposed to coma)

2

possible purposes of sleep (x4)

- glycogen replacement
- restorative (heart rate, respiration, body temp, O2 use)
- neural development
- learning? (possibly confounded by effects of stress on learning)

3

inherent circadian rhythm period in humans

about 25 hours

4

Stages of sleep primarily determined with ___

EEG

5

SWS

slow wave sleep

6

In SWS, ___ waves are dominant in EEG

delta (high amplitude, 0.5-4 Hz)

7

First few hours of sleep dominated by ___

slow wave sleep

8

Later few hours of sleep show increased ___

REM sleep

9

Fast EEG is [more/less] in REM over SWS

more

10

Muscle activity is [more/less] in REM over SWS

more

11

Dreaming is [more/less] in REM over SWS

more

12

Eye movements are [more/less] in REM over SWS

more

13

Brain metabolism is [more/less] in REM over SWS

more

14

Delta (and other sleep) waves result from changes in ___

activity of thalamocortical neurons

15

Thalamic neurons are [depolarized/hyperpolarized] during wakefullness

depolarized, for sensory transmission

16

Thalamic neurons are [depolarized/hyperpolarized] during sleep

hyperpolarized, to filter input

17

Mechanism of slow oscillations seen in SWS

1. most thalamic neurons hyperpolarized so that external stimuli do not reach cortex
2. hyperpolarization triggers depolarizing currents
3. activation of I_h Na+ channels and action potentials in thalamic neurons
4. synchronous PSPs and action potentials in cortical neurons
5. GABA neurons in reticular nucleus of thalamus activation
6. release of GABA causes re-hyperpolarization in thalamus, cycling

18

melatonin [incr./decr.] SWS duration by ___

increases duration b/c reticular nucleus neurons express melatonin receptors, so melatonin induces bursts of firing that inhibits thalamus and prolongs SWS duration, and possibly helps trigger SWS

19

REM-on neurons are located in ___

pontine reticular formation (aka pontine tegmentum?)

20

REM-on neurons release ___ onto ___ neurons, causing [hyperpolarization/depolarization]

Ach, thalamic, depolarization

21

Areas that change in activity during dreaming

- limbic system active (emotion)
- prefrontal cortex decreased (reduced inhibition of 'social innapropriate though'?
- decreased working memory (forgeting dreams)

22

To reduce movement, REM-on neurons send [excitatory/inhibitory] projects to neurons in ___

excitatory, lower brainstem

23

Mechanism of reduced movement during sleep

REM-on pontinue reticular neurons send excitatory projects to neurons in lower brainstem
-> These project to motor neurons, where they release inhibitory GABA or glycine
-> This produces 'active paralysis'

24

Lesioning ___ causes animals to appear to act out dreams

pontine reticular formation

25

catalepsy

sudden paralysis

26

REM-off neurons located in ___ and ___ (?)

raphe nuclei and locus ceruleus

27

Mechanism of exiting REM sleep

REM-off neurons project from raphe nucleus and locus ceruleus to REM-on neurons in pontine reticular formation
-> 5-HT and NE inhibit REM-on cells
-> REM is turned off

28

Arousal involves which systems (x4)

- midbrain reticular formation
- posterior hypothalamic neurons
- nucleus basalis
- locus ceruleus

29

Characteristics of narcolepsy (x5)

- sudden sleep attacks, often during emotion
- loss of muscle tone
- hallucinations
- abnormal sleep/wake cycles
- relation to hypocretin/orexin

30

Hypocretin neurons are [incr./decr.] in humans with narcolepsy

decr.