Sleep

Question 1

EEG records very small electrical fields generated by syanaptic currents in cortical ______

Answer 1

EEG records very small electrical fields generated by syanaptic currents in cortical pyramidal cells

Question 2

describe what is seen in the EEG

Answer 2

• cortical activity causes high (voltage) amplitude EEG waves; found in the sleeping brain

Question 3

describe what is seen in the EEG

Answer 3

• cortical activity causes low (voltage) amplitdue EEG waves; normal awake brain

Question 4

Answer 4

Question 5

Answer 5

Question 6

Answer 6

Question 7

Answer 7

seen in a comatose/unconscious person

Question 8

Answer 8

Question 9

describe this hypnogram

Answer 9

Question 10

describe sleep pressure

Answer 10

• homeostatic process that keeps track of how long we have been awake
• the longer we are awake, the greater the build-up of sleep pressure, possibly reflected by adenosine levels
• sleep pressure interacts with the circadian sleep rhythm

Question 11

describe the sleep pressure graph

Answer 11

Question 12

contrast arousal vs sleep systems

Answer 12

• arousal systems (cholinergic and monoaminergic pathways) and sleep-promoting systems (GABA-ergic pathways) are mutually inhibited by turning off each other’s circuitry
• the circuitry that governs sleep/wake cycling is analogous to a flip-flop electrical switch with either an ON state or OFF state
  
  • the switch is controlled by GABA containing neurons in the ventrolateral preoptic region (VLPO) of the ant. hypothalamus that turn off arousal systems in the asecnding reticular activating system (ARAS)

Question 13

describe the components involved in the ARAS (ascending reticular activating system)

Answer 13

• PPT: pedunculopontine nuclei = cholinergic
• LDT: laterodorsal tegmental nuclei = cholinergic
• RN: raphe nuclei = serotonin
• LC: locus ceruleus = norepi
• VT: ventral tegmentum = dopamine

Question 14

describe the hypothalamic components involved in wakefulness

Answer 14

• hypothalamus
  
  • LH: lateral hypothalamus
  • TMN: tuberomammillary bodies

Question 15

describe the basal forebrain components involved in wakefulness

Answer 15

• basal forebrain
  
  • septal nuclei
  • nucleus basalis

Question 16

describe the components of the brain involved in sleep

Answer 16

• hypothalamus
  
  • VLPO: ventrolateral preoptic region
    
    • GABA-ergic that inhibits wakefulness

Question 17

the ____ promotes ____ and ____ during the wake period

____ projections to the ____ influence the firing patterns of sensory relay neurons

Answer 17

the cholinergic system (ACH) promotes thalamic and cortical during the wake period

ACH projections to the thalamus influence the firing patterns of sensory relay neurons

Question 18

the ____ contains sensory relay stations whare are in “_____” during waking state but go into “____” during slow wave sleep (SWS)

Answer 18

the thalamus contains sensory relay stations whare are in “transmission mode” during waking state but go into “burst mode” during slow wave sleep (SWS)

Question 19

describe the activity of these thalamic neurons and in what state they are found

Answer 19

Question 20

how does the suprachiamastic nucleus influence sleep?

Answer 20

• the SCN has minimal projections to the VLPO
• SCN strongly innervates the subparaventricular zone (SPZ) of the hypothalamus and the dorsomedial hypothalamic nuclei (DMH)
  
  • DMH integrates feeding, temp. and light cues from SPZ and SCN
  • DMH has GABAergic projections to the VLPO and excitatory projections to the LH

Question 21

there is transient ____ activation during REM sleep

Answer 21

there is transient cholinergic cell activation during REM sleep

Question 22

compared to SWS, REM involves increased _____ in:

Answer 22

compared to SWS, REM involves increased blood flow in:

• pons, midbrain, basal gang
• paralimbic regions
• association cortices

Question 23

____ activity higher in ____ than in awake brain

Answer 23

paralimbic activity higher in REM than in awake brain

Question 24

describe why there is paralysis during REM sleep

Answer 24

• glycinergic ventromedial medulla nerons inhibit spinal motor neurons during REM-associated motor atonia

Question 25

summarize the sleep stages

Answer 25

Question 26

describe memory and sleep

Answer 26

* memory encoding takes place during the waking state, whereas memory consolidation is facilitated during the sleeping state due to the lack of interference from incoming sensory stimuli