Ch. 8.2. Stages of Sleep and Brain Mechanisms Flashcards
What do large, slow waves on an EEG indicate?
Large, slow waves indicate a low level of activity, with much synchrony of response among neurons.
The stages of sleep
Stage 1: Irregular, jagged, low woltage sleep
Stage 2: K-komplex and sleep spindles
Stage 3-4: Slow wave sleep
Stage 5: REM/paradoxical sleep
A sleep bindle is a burst of 12- to 14-Hz waves for at least half a second. Sleep spindles result from oscillat- ing interactions between cells in the ______ and the _____
thalamus (and the) cortex
How can an investigator determine whether a sleeper is in REM sleep?
Examine EEG pattern and eye movements.
During which part of a night’s sleep is REM most common?
REM becomes most common toward the end of the night’s sleep.
Why do most antihistamines make people drowsy?
A pathway from the hypothalamus uses histamine as its neurotransmitter to increase arousal. Antihistamines that cross the blood–brain barrier block those synapses.
What would happen to the sleep–wake schedule of someone
who lacked orexin?
Someone without orexin would alternate between brief periods of waking and sleeping.
Orexin is important for staying awake
Sleep depends partly on decreased sensory input to the _____ ______. During sleep, neurons in the ______ become hyper- polarized, decreasing their readiness to respond to stimuli and decreasing the information they transmit to the cortex
cerebral cortex
thalamus
What would happen to sleeping and waking if you took a drug that blocked GABA?
You would remain awake, or at least somewhat conscious. (Tranquilizers put people to sleep by facilitat- ing GABA to inhibit synapses.)
Someone who has just awakened sometimes speaks in a loose, unconnected, illogical way. How could you explain this finding?
People often awaken from a REM period, because REM is abundant toward morning when people usually awaken.
Different brain areas don’t wake up allat once.
Shortly after awakening, certain brain areas may still be in a REM-like state, and thinking may have an illogical, dreamlike quality.
What kinds of people are most likely to develop sleep apnea?
Sleep apnea is most common among people with a genetic predisposition, old people, and overweight middle-aged men.
What is the relationship between orexin and narcolepsy?
Orexin is important for staying awake. Therefore, people or animals lacking either orexin or the receptors for orexin develop narcolepsy, characterized by bouts of sleepiness during the day.
Sleep spindles in stage 2 sleep appear to be important for _______ ________ ____ ?
Consolidation of memory
What do the high-amplitude slow waves of slow-wave sleep indicate?
Synchrony among neurons
At which time is slow-wave sleep most common?
Not immediately, but during the early part of the
night’s sleep
