Intro to Sleep + Techniques - Forster, Franco Flashcards
What is the definition of sleep? How do you differentiate sleep from coma or anesthesia?
Sleep: Unconsciousness from which th person can be aroused by sensory or other stimuli.
Coma / Anesthesia: Person cannot be aroused.
Describe the putative functions of NREM vs. REM sleep.
NREM: “physical upkeep”
- Growth, tissue repair, waste clearance
- Immune system enhancement
- Restoration of cerebral energy stores
REM: “mental upkeep”
- Information processing
- Purging of irrelevant information
- Memory consolidation
- Facilitates learning & memory
Name the stage of sleep in which the following are noted:
- Alpha waves
- Theta waves
- Delta waves
- Sleep Spindles
- K complex
- Sawtooth waves
- Alpha waves: Awake / Drowsy
- Theta waves: Stage 1
- Delta waves: Stages 3 & 4 (Deep)
- Sleep Spindles: Stage 2
- K complex: Stage 2
- Sawtooth waves: REM
- Describe general sleep architecture for a healthy young adult.
- How does this differ from infant sleep architecture?
- From sleep architecture in the elderly?
- Initial progression from Stage 1 → 4. After a while in deep sleep, rise back through earlier stages before arriving at REM. After a short REM period, sink back into deep sleep. As further cycles occur, REM periods become longer and more frequent, and the lowest level of sleep reached becomes shallowed (around Stage 2 instead of deep sleep).
- Infants may sleep for less time contiunuously, but have more total sleep during a day, as well as more REM sleep.
- The elderly have little deep (Stages 3 & 4) sleep, less REM, and their sleep is more fractionated with more cycles.
Approximately how much of a full night’s sleep is spent in each of the following sleep stages?
- Stage 1 (N1)
- Stage 2 (N2)
- Stages 3 & 4 (N3)
- REM (R)
- How much does REM decrease with age?
- N1: 2-8%
- N2: 45-55%
- N3: 13-23%
- R: 20-25%
- Decreases ~1.0% of absolute per decade
Do you dream in NREM or REM sleep?
Both, but typically only REM dreams are recalled.
What phase of sleep is called paradoxical sleep, and why?
REM sleep, because it is similar to wakefulness in terms of EEG readings.
In a popular model of the sleep-wake cycle, two major processes are said to control wakefulness vs. sleepiness. Name and describe these two processes.
- Process H: Homeostatic process. The longer awake, the greater propensity to sleep.
- Process C: Circadian oscillatory process that affects the propensity for sleep vs. wakefulness dependent on the time of day.
- What part of the brain controls the circadian rhythm?
- The circadian rhythm can be trained / reset to match the day length. How is this accomplished?
- Suprachiasmatic nucleus (SCN) of the hypothalamus
- About 10,000 neurons
- Environmental photoperiod is matched via photoreceptors in the retina which communicate with the SCN
- These photoreceptors are seperate from those used in sight
- How long is the normal period of the circadian rhythm?
- How long is the period of the circadian rhythm if environmental cues are removed (e.g. all natural light, complete retinal blindness)?
- 24 hours
- 26 hours
Name the patterns of sleep indicated by the blue, pink, and red lines.
For each of the factors listed below, state whether that factor is wake-promoting or sleep-promoting.
- Cytokines (e.g. interleukins)
- Adenosine
- Serotonin
- Epinephrine
- Cortisol
- Prostaglandin D2
- Somatostatin
- Histamine
- Glutamate
- Cytokines: Sleep
- Adenosine: Sleep (caffeine blocks adenosine receptors)
- Serotonin: Can be either!
- Epinephrine: Wake
- Cortisol: Wake
- Prostaglandin D2: Sleep
- Somatostatin: Sleep
- Histamine: Wake
- Glutamate: Wake
- Neurons in the raphe pallidus produce ________.
- Neurons in locus coeruleus produce ________.
- Neurons in the PPT and LDT produce ________.
- Serotonin
- Norepinephrine
- Acetylcholine
During REM sleep, state whether activity from each of the following brain areas increases or decreases. What is the interaction between these areas?
- Locus coeruleus
- Raphe pallidus
- LDT/PPT
- Gigantocellular tegmental field (FTG)
- Decreases
- Decreases
- Increases
- Increases
Decreased NE and 5-HT from 1 + 2 release inhibition of 3 + 4, which produce ACh and activate REM.
Compared to wakefullness, REM sleep has (increased / decreased):
- Norepinephrine
- Serotonin
- Acetylcholine
- Decreased
- Decreased
- Increased