Previous Lectures

Question 1

What is the Regular Activating System (RAS)? (DBSEC)

Answer 1

• determines level of alertness
• brain stem, thalamic relay station
• sensory nerve pathways meet, talk to relay neurons which talk to cortex
• excites relay neurons
• coordinates sleep/wake cycle

Question 2

What are the pons? (CRC)

Answer 2

• connect 2 sides of cerebellum, controls autonomic function
• REM motor paralysis/atonia
• continue functioning smooth muscle: diaphragm, intestines/stomach

Question 3

What is the Superchiasmatic Nucleus (SCN)? (LSIP)

Answer 3

• location of “biological clock”
• synchronise w/ light-dark cycles of environment
• influences endocrine system
• promotes wakefulness

Question 4

What are biochemical “players”? (AAGGHML)

Answer 4

Acetylcholine: NT during low-voltage & high frequency EEG (waking & REM)

Adenosine: builds up when awake, abated w/ caffeine

Glutamate: excitatory NT, helps produce slow waves & spindles

Glyine: inhibitory NT, spinal cord
- assists in paralysis during REM

Histamine: hypothalamus, produce wake state

Melatonin:

- mildly sleep producing, speed sleep onset
- stays high until wakening
- light blocks production

Leptin: hormone

- elevates during sleep
- reduces appetite, hunger
- converse w/ ghrelin

Question 5

What is electroencephalogram (EEG)? (EUMEMV)

Answer 5

measurement of surface brainwaves: manifestation of bioelectric activity

Question 6

What is electrooculargram (EOG)? (ETERP)

Answer 6

electrical activity measured when eyes move under closed eyelids

Question 7

What is electromyogram (EMG)? (ERGM)

Answer 7

measures electrical activity from continuous contraction of muscle fibers

Question 8

What is relaxed wakefulness in terms of recordings?

Answer 8

• EEG:
  
  • beta waves: irregular, sharp peaks & valleys
  • close eyes = start of alpha waves
• EOG: quick movement; eyes closed - slow-rolling begins
• EMG: highest amplitude

Question 9

What are N1 characteristics?

Answer 9

• EEG: theta waves, some alpha
• EOG: slow-rolling/pendular, possibly binocularly asynchronous, large movements
• EMG: reducing, some body movements
• sleep onset: retrograde amnesia, sleep starts/hypnic jerks

Question 10

What are N2 characteristics?

Answer 10

• EEG: “mid-amplitude”, sleep spindles, K complexes
• EOG: none
• EMG: reduced, w/ some phasic activity

Question 11

What are N3 characteristics?

Answer 11

• EEG: delta waves, K complexes
• EOG: none
• EMG: very few movements, phasic

Question 12

What are REM characteristics?

Answer 12

• EEG: similar to wake, saw tooth waves
• EOG: rapid, sporadic movement, mirror-image recording with quiet periods
• EMG: low, paralysis of voluntary muscles, “twitching” phasic bursts

Question 13

What is sleep latency?

Answer 13

time it takes from bedtime to sleep onset (MSLT)

- increase/strong sleep tendency = short/decreased sleep latency

Question 14

What is the biological clock?

Answer 14

consists of controls & timing mechanisms that maintain daily 24hr oscillations
- interaction based on transcription-translation feedback loops of “clock genes” & their protein products

Question 15

What is the opponent process model?

Answer 15

interaction of sleep homeostasis & clock-dependent alerting to produce sleep/wakefulness cycle