Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PSY290: Neurochemical Basis for Behaviour > Lecture 8: Sleeping > Flashcards

Lecture 8: Sleeping Flashcards

1
Q

What is a circadian rhythm? Infradian? Ultradian?

A

24 hour cycles, longer than a day (shorter than a year), ultradian (shorter than a day).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name 5 examples of biorhythms:

A
  1. core body temp
  2. urine volume
  3. melatonin
  4. cortisol
  5. growth hormone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do we know that light is not behind circadian rhythms?

A

Wheel-running behavior shows periodic variation in rodents throughout the day. Also, nocturnal rodents run more at night.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are internal biorhythms? How do we know they exist?

A

Rhythmic cycles that exist without light. They are endogenous to organisms. When humans are placed in a bunker and could control when lights are on-off the sleep-wake cycle shifted from 24 to 25-27 hours.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are zeitgebers?

A

Time givers, for example clocks. When light cues are delivered at bad times, different from our zeitgebers, our normal rhythms are disrupted (i.e., jet leg, light pollution).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does our body get entrained to light?

A

1-3% of retinal ganglion cells (RGCs) express a light sensitive pigment (melanopsin) which is sensitive to blue light and always sends the signals if they are received. This signal is sent to the retinohypothalamic tract which leads to the hypothalamus (to the super charistmatic nucleus, SCN).This is right above the optic chiasm where the pathway dessucates to other areas of the brain. This signal entrains shell neurons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does a SCN lesion lead to?

A

The abolishment of many circadian rhythms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do we see in the SCN during the day of diurnal animals?

A

More activity, maintain rhythmic activity even when deprived of input (tracts being removed).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do SCN cells maintain their activity w/o input?

A

Because neurons in the SCN have rhythms of gene expression called period genes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the three period genes in the SCN?

A
  1. Cryptochrome genes (CRY1 and CRY2)
  2. Clock Protein
  3. BMAL Protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What was the CRY1 gene associated with?

A

Delayed sleep phase disorder (a condition where you got to bed and rise later than socially appropriate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where does melatonin production happen? What is it inhibited by? What is its role?

A

Pineal gland. Light. Plays a role in sexual maturity. In the winter there is less light so more melatonin, smaller gonad size. Evolutionarily adaptive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where does cortisol production happen?

A

Paraventricular nucleus (PVN)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What rises first before waking, melatonin on cortisol?

A

melatonin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the effect of exercise on biorhythms?

A

The dorsal raphe (DRN) + median raphe (MRN) mediate the influence of exercise on SCN activity. Results in strengthened biorhythms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are two conditions where you get a phase advance?

A
  1. Daylight earlier

2. Exercising early

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the reticular activating system (RAS)?

A

It is sensitive to sensory input. It stimulates reticular formation which promotes arousal. It is connected to the basal forebrain which sends cholinergic inputs to the rest of the brain (choline). Coma can occur with injury to the dorsal pontine reticular formation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do we know what the RAS does?

A
  1. Damage to the RAS or its input channels to higher brain centers, we see an EEG similar to sleep.
  2. When you stimulate this area during sleep, the animal wakes up.
  3. When you cut off brain stem input to the RAS you would not affect the rhythmicity of the EEG.
  4. Cat slide?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why do we need sleep? (6)

A
  1. Maintenance of brain
  2. Restoration of injured tissue
  3. Ontogenetic development of the brain
  4. Maintenance of learning + memory processes
  5. Energetically favorable
  6. Dreaming
20
Q

What is meant by the maintenance of the brain? (3)

A
  1. Certain metabolites are best cleaned during sleep (i.e., Alzheimer’s is when this doesn’t happen)
  2. More sleep is associated with better memory and cognitive performance (memory consolidation)
  3. Neural networks formed during sleep which lay a foundation for future learning.
21
Q

What happens in the HC during sleep after a spatial task?

A

Cells in the hippocampus that were involved in the task become linked (show correlative activity) during NREM sleep (evidence from rodents and humans).

22
Q

What happens in the motor cortex during sleep after a motor task?

A

In humans, neurons involved in executing an implicit motor task may again become active during sleep (similar but not identical pattern of activity).

23
Q

What is pre-play?

A

During sleep, neural networks are built to store future memories (e.g. like humans, neurons involved in executing an implicit motor task may again become active during sleep (similar but not identical pattern of activity).

24
Q

Describe the sleep stages and their EEG signatures?

A
  1. Awake: Beta >13 Hz
  2. Drowsy: Alpha 7-13 Hz
  3. Stage N1 sleep (NREM1 - light sleep): Theta 4-7 Hz (alpha + theta)
  4. Stage N2 sleep: sleep spindles (theta) with spindles and K-complexes
  5. Stage N3: Delta 1-4 Hz (deep sleep or slow wave sleep, some spindles), efficient sleepers (<6 hours) spend more time in NREM3
  6. REM (Dream Stage): fast and random (activity is similar to wakefulness)
25
Q

What’s the difference between the sleep signatures of children vs older adults?

A

Young children: most sleep is REM. Older adults, less REM, less deep sleep, greater sleep latency, more arousal periods (awakenings), less REM, less NREM3, less sleep overall.

26
Q

What is atonia and when does it happen?

A

Atonia is lack of muscle tone produced by the subcoerulear nucleus exciting the magnocellular nucleus of the medulla which inhibits spinal motor neurons.

27
Q

What are REM related activities?

A

Neocortex activated by basal forebrain nuclei. Excited brainstem nuclei produce REM and other twitching movements.

28
Q

What does REM deprivation lead to?

A

Lack of REM is associated with reduced hippocampal neurogenesis, immune dysfunction and mood disruption (suppression of REM occurs with antidepressants which improve mood).

29
Q

What happened when you replaced REM states with wakeful states?

A

Prevented REM rebound which is an increased amount of sleep a person received as a result of being sleep deprived or stressed during waking hours.

30
Q

What are the theories for dreaming? (3)

A
  1. Theory of wish fulfillment (act out repressed desires - Freud)
  2. Activation-Synthesis Theory (dream states an attempt by the brain to interpret random activity)
  3. Evolutionary theory (dreams include events that are a threat to reproductive success, we devise new ways to manage these threats)
31
Q

What are the types of objective methods to study sleep?

A
  1. Physiology during sleep, neurological activity during sleep (using EEG = electrical activity, EMG = breathing activity, EOG = eye movement)
  2. Actigraphy: the actigraph measures sleep-wake times and can be used to verify a sleep diary (no technician needed)
32
Q

What are the types of subjective methods to study sleep?

A

Asking patients about their sleep patterns (self-report and questionnaires. First and necessary step that relies upon honest and accurate reports by patient.

33
Q

What are the types of subjective reports?

A
  1. Athens Insomnia Scale
  2. Pittsburgh Sleep Quality Index
  3. Insomnia Severity Index
34
Q

What is the DEC gene mutation associated with?

A

Associated with less sleep (slept 4-5 hours a day)

Mice w/similar DEC2 gene mutations sleep less.

35
Q

What is a quantitative trait?

A

A trait modulated by many genes.

36
Q

What is a chronotype?

A

Sleep schedule.

As you grow up, your chronotype changes (by your 20s your chronotype moves back, you wake up earlier and earlier).

37
Q

Gender and age differences in chronotypes?

A

Men are more likely to have a later chronotype (wake up later). From child - 20, your chronotype moves forward.

38
Q

Why is GPA negatively correlated with dim-light melatonin onset?

A

Low amounts of melatonin = low sleep pressure. The higher your GPA, the lower the dim-light melatonin.

39
Q

What are short/long term effects of sleep disruption?

A

Short term: Stress, somatic, psychological issues.

Long-term consequences: cardiovascular disease, obesity, T2DM, Cancer, Death

Check out the physiological effects

40
Q

What are sleep problems associated with?

A

Associated with impairments in motivation and attention (more than cognition)
Associated with weight gain and immune dysfunction.

41
Q

What happens during exam season?

A

Less sleep, more cortisol, self-report of stress is higher (but overreporting based on cortisol).

42
Q

What is insomnia?

A

Difficulty falling asleep or staying asleep. Can be acute or chronic, and may reoccur.
Primary insomnia is rare (~10% of cases) whereas secondary/comorbid insomnia (90%) common.
Insomnia is commonly comorbid with neuropsychiatric disorders such as depression and anxiety (33% of all insomnia is linked to these two disorders).

43
Q

What is cataplexy?

A

Loss of motor control (atonia) without loss of consciousness
Triggered by arousing stimuli (e.g. laughing, crying, terror, running)
Common in narcolepsy (70% of cases).

44
Q

How does cataplexy happen?

A

Atonia is caused when specialized neurons inhibit motor neurons
These neurons are inhibited by orexin-expressing neurons in the lateral hypothalamus.
Loss of OX neurons leads to increased activity of the specialized cells which inhibit motor neurons + atonia. Immuno activity destroys these OX neurons.
Supplementing with orexin can help (restores normal behavior).

45
Q

What is narcolepsy?

A

Characterized by extreme daytime sleepiness (tested by waking people up during sleep to see how fast REM sleep happens)
Rapid descent into REM sleep is common.
The disorder is treated with amphetamine or GABA agonists or orexin/hypocretin peptides (to mimic the signaling compounds that have been lost).

46
Q

What is somnambulism?

A

A disorder in which the person leaves the bed an moved around
More common in childhood (~12 years), only 4% of adults experience it
There have been reports of complex, aggressive and illegal behaviors while sleepwalking
Somnambulism occurs during NREM but not REM.

PSY290: Neurochemical Basis for Behaviour (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions