CH27 cortical states and sleep

Question 1

George takes part in a circadian rhythm experiment. After spending a few days with lights coming on at 6:00 A.M. and going off at 10:00 P.M., he is subjected to constant low light. What will the George’s activity pattern look like during the constant low light conditions?
a. He will continue to wake at 6:00 A.M. and go to bed at 10:00 P.M. every day (same schedule).
b. He will continue to wake at 6:00 A.M. but go to bed at 3:00 P.M. every day (more sleep).
c. He will begin to wake and go to bed slightly later each day (shifted schedule).
d. He will sleep for short, random periods throughout the day (no schedule).
e. He will continue to wake at 6:00 A.M. but go to bed at 2:00 A.M. every day (less sleep).

Answer 1

c. He will begin to wake and go to bed slightly later each day (shifted schedule).

Question 2

Which photopigment plays an important role in entrainment to a circadian cycle?
a. Melanopsin
b. Rhodopsin
c. Pinopsin
d. Neuropsin
e. Photopsin

Answer 2

a. Melanopsin

Question 3

How do the light-sensitive cells responsible for entrainment differ from rod and cone photoreceptors?
a. They are located in the retinal bipolar layer.
b. They are located in the pineal gland.
c. They release GABA.
d. They project to the thalamus.
e. They are depolarized by light.

Answer 3

e. They are depolarized by light.

Question 4

If activity in the photosensitive retinal ganglion cells was inhibited, which region would lose direct input?
a. The lateral geniculate nucleus in the thalamus
b. The suprachiasmatic nucleus in the hypothalamus
c. The medial geniculate nucleus in thalamus
d. The medial preoptic area in the hypothalamus
e. The visual cortex

Answer 4

b. The suprachiasmatic nucleus in the hypothalamus

Question 5

Removal of light cues would directly alter transcription of which genes in a mammal?
a. Per1, Per2, and Per3
b. Cry and Ccg
c. Clk and Cry
d. Clk and Bmal1
e. Bmal1 and Per1

Answer 5

d. Clk and Bmal1

Question 6

What causes beta rhythm waves to have small amplitudes and delta rhythm waves to have high amplitudes?
a. The inputs to cortical neurons are synchronized while awake, but irregular during sleep.
b. The inputs to cortical neurons are irregular while awake, but synchronized during sleep.
c. More neurons are being recorded from while awake than asleep.
d. Fewer neurons are being recorded from while awake than asleep.
e. The thalamus has a stronger output during sleep than during wakefulness.

Answer 6

b. The inputs to cortical neurons are irregular while awake, but synchronized during sleep.

Question 7

Which function is not currently being considered as a purpose of sleep in humans?
a. Replenishing brain glycogen levels
b. Conserving resources
c. Consolidating memories
d. Clearing metabolic waste produced by neurons from the brain
e. Resynthesizing neurotransmitters lost throughout the day

Answer 7

e. Resynthesizing neurotransmitters lost throughout the day

Question 8

An elderly patient complains of long-term insomnia. What other disorder might the patient suffer from, considering its co-ocurrance with severe insomnia?
a. Autism
b. Alzheimer’s disease
c. Parkinson’s disease
d. Myasthenia gravis
e. Major depression

Answer 8

e. Major depression

Question 9

A 60-year old, overweight patient is having trouble staying asleep during the night. His wife says he sleeps so soundly he barely moves, and at times he loudly inhales and jerks awake. The patient most likely has which sleep disorder?
a. Narcolepsy
b. Sleep apnea
c. Insomnia
d. Chronic fatigue syndrome
e. Restless leg syndrome

Answer 9

b. Sleep apnea

Question 10

Which neurological system has been shown to be dysfunctional in narcoleptic patients?
a. Serotonin
b. Orexin
c. GABA
d. Histamine
e. Acetylcholine

Answer 10

b. Orexin

Question 11

Why do animals like giraffes sleep for only a few minutes at a time?
a. They have less need for memory consolidation than other animals that sleep longer.
b. They have evolved to generate less neuronal metabolic waste during the day.
c. As prey, they must remain constantly aware of their surroundings.
d. They have high energy needs and must eat constantly throughout the day.
e. Amount of sleep is correlated with body size; the larger the animal, the lower the requirement for sleep.

Answer 11

c. As prey, they must remain constantly aware of their surroundings.

Question 12

Sleep spindles occur during which sleep stage?
a. Stage I
b. Stage II
c. Stage III
d. Stage IV
e. REM

Answer 12

b. Stage II

Question 13

As an individual moves from the awake state through stage IV sleep, the EEG patterns
a. increase in amplitude and decrease in frequency.
b. increase in both amplitude and frequency.
c. decrease in amplitude and increase in frequency.
d. decrease in both amplitude and frequency.
e. do not change in amplitude but increase in frequency.

Answer 13

a. increase in amplitude and decrease in frequency.

Question 14

Which evidence best supports the notion that sleep is important for consolidating memories?
a. When awakened from sleep, humans often report dreams that are related to experiences of the previous day.
b. Depriving humans of REM sleep leads to reduced cognitive abilities.
c. Patients taking selective serotonin reuptake inhibitors (antidepressant medication) are more successful at memory tasks than controls.
d. In rodents, neurons in the hippocampus that were active during a spatial memory task are reactivated during sleep.
e. The dorsolateral prefrontal cortex shows increased activity during REM sleep.

Answer 14

d. In rodents, neurons in the hippocampus that were active during a spatial memory task are reactivated during sleep.

Question 15

Refer to the figure.
Which brain region was stimulated (yellow bar in figure) to produce the change in cortical state shown?
a. Reticular activating system
b. Dorsolateral prefrontal cortex
c. Anterior cingulate cortex
d. Rostral interstitial nucleus
e. Parahippocampal gyrus

Answer 15

a. Reticular activating system

Question 16

If you were conducting a rodent sleep study in a research lab and needed to lesion the orexin neuron group, which brain region would you need to target?
a. Thalamus
b. Pons
c. Reticular formation
d. Hypothalamus
e. Cerebellum

Answer 16

d. Hypothalamus

Question 17

Which set correctly pairs the brainstem nucleus with its neurotransmitter?
a. Tuberomammillary nucleus—acetylcholine
b. Locus coeruleus—dopamine
c. Cholinergic nuclei—norepinephrine
d. VPLO—histamine
e. Raphe nuclei—serotonin

Answer 17

e. Raphe nuclei—serotonin

Question 18

Which type of drug would most likely be helpful as a sleep aid?
a. Adenosine receptor antagonist
b. Orexin receptor antagonist
c. Acetylcholinesterase Inhibitor
d. Selective serotonin reuptake inhibitors
e. Histamine receptor agonist

Answer 18

b. Orexin receptor antagonist

Question 19

Which type of drug could be used to stabilize thalamic neurons in the oscillatory, or bursting, state?
a. Acetylcholine agonist
b. Selective serotonin reuptake inhibitors
c. Orexin receptor agonist
d. GABA agonist
e. Adenosine receptor antagonist

Answer 19

d. GABA agonist

Question 20

A human in a cave, deprived of all time clues, would
a. maintain an essentially perfect 24-hour sleep–wake cycle for several months.
b. sleep in brief bouts, like a giraffe does.
c. begin free-running (i.e., would operate on a cycle of approximately 24-hours, based on the internal clock).
d. oscillate between cycles much shorter than 24 hours and cycles much longer than 24 hours.
e. sleep almost all the time.

Answer 20

c. begin free-running (i.e., would operate on a cycle of approximately 24-hours, based on the internal clock).

Question 21

The entrainment of our body’s circadian rhythm to the environmental light–dark cycles is mediated by
a. rod photoreceptors in the retina.
b. cone photoreceptors in the retina.
c. specialized retinal ganglion cells.
d. photoreceptors within the SCN.
e. photoreceptors in the pineal gland.

Answer 21

c. specialized retinal ganglion cells.

Question 22

The sleep-promoting substance melatonin
a. is produced by the pituitary gland.
b. is synthesized from the chemical precursor tyrosine.
c. reaches a maximum blood concentration between 2:00 and 4:00 A.M.
d. is produced in greater amounts in the elderly.
e. provides dramatic relief in cases of fatal familial insomnia.

Answer 22

c. reaches a maximum blood concentration between 2:00 and 4:00 A.M.

Question 23

Which statement about the EEG is false?
a. It has virtually no clinical value because of its poor spatial resolution.
b. Its temporal resolution can resolve different-frequency brain waves.
c. It can detect distinct rhythms or frequency bands in different regions of the brain.
d. EEG rhythms depend in part on activity of the thalamus.
e. The functional significance of cortical oscillations detected by EEG is unknown.

Answer 23

a. It has virtually no clinical value because of its poor spatial resolution.

Question 24

Which statement about human sleep cycles is false?
a. Adults, on average, need about 7.5 hours of sleep a night.
b. The need for sleep increases with age.
c. Body temperature decreases at night.
d. Growth hormone increases at night.
e. Cortisol levels begin to increase toward early morning.

Answer 24

b. The need for sleep increases with age.

Question 25

Dolphins and some birds share a unique sleep style in that
a. they have only REM sleep.
b. they sleep in very brief bouts that last only a few minutes at a time.
c. they sleep only for a few minutes a day.
d. only half their brain (or cerebrum) sleeps at a time.
e. they alternate on a regular basis between sleeping during the day and sleeping at night.

Answer 25

d. only half their brain (or cerebrum) sleeps at a time.

Question 26

The deepest stage of sleep is _______ sleep.
a. spindle-wave
b. slow-wave
c. REM
d. stage I
e. stage II

Answer 26

b. slow-wave

Question 27

Slow-wave sleep
a. is characterized by sleep-spindles.
b. includes stage III and stage IV sleep.
c. occurs only once a night.
d. is characterized by rapid eye movements.
e. is characterized by EEG oscillations in the 100 to 200 Hz range.

Answer 27

b. includes stage III and stage IV sleep.

Question 28

Which physiological change is not characteristic of non-REM sleep?
a. Rolling eye movements
b. Decreased body temperature
c. Decreased heart rate
d. Penile erection
e. Decreased blood pressure

Answer 28

d. Penile erection

Question 29

Which statement does not describe a theory or view offered to explain REM sleep and/or dreaming?
a. During dreaming, the conscious ego relaxes its hold on the subconscious “id.”
b. REM is necessary for survival because the eye movements prevent fixation blindness.
c. REM consolidates memories by strengthening relevant synaptic connections.
d. REM helps expunge intrusive or “parasitic” modes of thought.
e. Dream content is cognitive “trash” as much as it is “treasure.”

Answer 29

b. REM is necessary for survival because the eye movements prevent fixation blindness.

Question 30

The reticular activating system
a. is a region of forebrain that activates the rest of the brain.
b. is a thalamocortical loop involved in attention.
c. includes a group of brainstem cholinergic neurons that induces wakefulness.
d. defines a cerebellar region that becomes active at the end of a sleep cycle.
e. is a reticular or mesh-like network that wraps around the cerebrum.

Answer 30

c. includes a group of brainstem cholinergic neurons that induces wakefulness.

Question 31

Which statement about REM sleep is false?
a. Pontine reticular signals trigger eye movements by activating the superior colliculus.
b. REM sleep EEG waves propagate through thalamus to cortex and are called PGO waves.
c. Activity in the amygdala, parahippocampus, and anterior cingulate cortex increases during REM sleep.
d. The influence of the frontal cortex decreases markedly during REM sleep.
e. Many of the eye movements during REM sleep are caused by light leaking through the eyelids.

Answer 31

e. Many of the eye movements during REM sleep are caused by light leaking through the eyelids.

Question 32

Antihistamines make people drowsy because they
a. inhibit the cholinergic nuclei in the brainstem.
b. excite several classes of neurons in the raphe.
c. mimic noradrenaline and serotonin at several metabotropic receptors.
d. are selectively taken up by VLPO neurons.
e. block the effects of tuberomammillary hypothalamic neurons.

Answer 32

e. block the effects of tuberomammillary hypothalamic neurons.

Question 33

A rodent undergoes a lesion to the lateral hypothalamus. You would expect the animal to show symptoms similar to which human disorder?
a. Narcolepsy
b. Restless leg syndrome
c. Insomnia
d. Sleep apnea
e. Chronic fatigue syndrome

Answer 33

a. Narcolepsy

Question 34

Which statement about thalamocortical circuits is false?
a. Reciprocal projections connect the thalamus and cortex.
b. Thalamic neurons can exist in a bursting state or a tonically active state.
c. A thalamic bursting state coincides with periods of heightened awareness.
d. Cholinergic and noradrenergic activity promote a tonic firing state.
e. A tonic state is believed to be associated with transmission of external information to cortex.

Answer 34

c. A thalamic bursting state coincides with periods of heightened awareness.

Question 35

The cells that receive cortical inputs and hyperpolarize thalamocortical neurons are
a. found throughout the brainstem.
b. a subset of the cholinergic cells of the reticular activating system.
c. GABAergic neurons found in the thalamic reticular nucleus.
d. the only cells that show low-threshold calcium spikes.
e. the primary source of the noradrenergic fibers ascending into cortex.

Answer 35

c. GABAergic neurons found in the thalamic reticular nucleus.