Brainscape's Knowledge GenomeTM

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


See full index

Disease B > Sleep disorders > Flashcards

Sleep disorders Flashcards

1
Q

What is sleep architecture

A

Changes in brain activity

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

How can you measure sleep architecture

A

EEG – put electrodes over scalp

Electroencephalogram

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

Describe sleep graph

A

You start awake then as the line goes down from stage 1 to 4 you go deeper and deeper into sleep
When you are awake electrical activity predominantly alpha and beta waves (higher frequency)
As you go down stage 4 delta waves predominate

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

What 2 categories is sleep separated into?

A
  • Sleep is separated into REM or NON-REM sleep

* REM sleep becomes longer and longer duration through the night

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

What is Non-REM

A

Stages 1-4
Slow wave sleep
Role in recuperation of body (recovering)

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

What is REM sleep

A

Rapid eye movement sleep

Role in memory, learning and creativity

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

What brain regions regulate sleep architecture?

These regions are important drug target regions

A

The reticular activating system (within brainstem)
Hypothalamus:

Lateral hypothalamus

Suprachiasmatic nucleus

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

The reticular activating system (within brainstem): -

A
  • Locus coeruleus (active during wakefulness) main neurones which project to locus coeruleus are noradrenergic – linked to anxiety
  • Raphe nuclei (promotes sleep) - site of origin of serotonin/5HT cell bodies
  • LC and RN work in opposition to eachother
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hypothalamus:

• Lateral hypothalamus –

A

orexin (hypocretin) promotes wakefulness
• Orexin is a peptide produced in hypothalamus which has effects on many parts of the brain including those that affect wakefulness

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

• Suprachiasmatic nucleus

A

regulates sleep-wake cycle

  • SCN responds to light input
  • The SCN then projects to pineal where levels of melatonin peak at night
  • Light induced activation of SCN prevents the production of melatonin by pineal gland
  • Melatonin promotes sleep
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Major sleep disorders

A
  1. Insomnia: difficulty in falling or remaining asleep that impairs daytime functioning – (affects 1/3 of adults) – could be trouble with sleep onset or sleep maintenance
    CAUSES include: stress, pregnancy and premenstrual syndrome
  2. Narcolepsy: a severe and persistent daytime sleepiness (lack of orexin)
  3. Sleep apnoea: a sleep related breathing disorder
  4. Restless leg syndrome: uncomfortable feelings in the legs with symptoms becoming worse when inactive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Treatment options for insomnia

A

• You want to avoid pharmacotherapy

Optimising sleep hygiene
• Directly address primary cause e.g. pain
• Cognitive behavioural therapy (talking therapy) (stimulus control, sleep restriction, relaxation)
• Light therapy – exposure to artificial light source at particular times of the day – regulates the SCN
• Medication (hypnotics such as Z drugs, benzodiazepines, melatonin)
• Herbal remedies (eg valerian)

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

Benzodiazapene and Z drug mechanism of action

A
  • These drugs are known as hypnotics
  • Similar mechanism of action – they both have the same target site
  • GABA has an influence on both serotonin and noradrenaline
  • GABA is an inhibitory neurotransmitter
  • Both benzodiazepines and Z drugs act on the GABA a receptor
  • GABA a receptor is an ionotropic receptor and ligand gated ion channel
  • GABA a receptor has 5 subunits: alpha, beta, gamma etc
  • GABA will usually bind to GABA a receptor between alpha and beta subunits
  • When GABA binds It will cause opening of central pore allowing negatively charged chloride ions to flood into the target cell
  • Therefore, hyperpolarising your target causing inhibition
  • GABA has to bind to a couple sites to cause that
  • There is also a benzodiazepine binding site between alpha and gamma subunit
  • Benzodiazepine is an allosteric modulator – changes the way receptor respond to stimulus
  • Benzodiazepines enhance the effect of GABA
  • GABA receptors with a1 and a5 subunit are responsible for hypnotic effects
  • NICE guidelines are that these drugs are prescribed for short term insomnia only
  1. benzodiazepine and Z drugs are structurally different, but they will both bind to the benzodiazepine site HOWEVER the affinity which they bind to the benzodiazepine site is governed upon the type of gamma and alpha subunit. Not all GABA a receptors are created equally
  2. GABA receptors related to sleep mechanisms tend to have either alpha 1 or 5 subunit in this area (right green box)
  3. Any drug that binds to benzodiazepine site where you got alpha 1 or 5 subunit is more likely to have a hypnotic effect
  4. The degree with which the drug binds influenced by gamma subunit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Benzodiazepines example

A
  • Unlike with the treatment of anxiety – a short duration of action is preferable
  • Flurazepam and nitrazepam (longer action)
  • Loprazolam, lormetazepam (shorter action, no hangover)
  • Benzodiazepines reduce sleep latency (time taken to fall asleep) but also disrupt sleep architecture reducing REM sleep
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Z drug example

A
  • Designed to exploit the beneficial hypnotic properties of benzodiazepine but with reduced adverse effects – Z drugs don’t affect REM sleep
  • Examples are zolpidem and zopiclone
  • Either bind to the a1 subunit (zolpidem) or alternate sites (zopiclone)
  • Binding can be influenced by overall subunit combination of GABAa receptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Z drug micro dialysis

A
  • The technique of micro dialysis enables the monitoring of neurotransmitters and other molecules in interstitial tissue fluid
  • Sampling neurotransmitter/drug overflow in discrete brain regions
  • Micro dialysis probe inserted into brain

Zolpidem increases acetylcholine release in pontine reticulum formation (important in sleep wake cycle) – you will promote sleepiness

17
Q

Findings from behavioural pharmacology

A
  • EEG studies in rodents show that zolpidem causes less REM disruption than triazolam
  • Tolerance to both benzodiazepines and Z drugs develops resulting in rebound EEG changes (rebound insomnia)
  • Zolpidem causes motor impairment in open field tests, but less effect on grip strength than benzodiazepines (Benzodiazepines are muscle relaxers)
  • Zolpidem has similar reinforcing effects to benzodiazepines – both drugs can cause person to become addicted and want more
18
Q

Benzodiazapene vs Z drugs similarities vs differences

A 
Similarities:
abuse potential
rebound insomnia 
impaired driving performance
binds to GABA a receptor
impair motor coordination

Differences:
more adverse effects with benzo
benzo affects REM, z doesnt
Benzo causes amnesia worse incomparison to z drug due to REM issue
larger suicical risk with benzo
benzo affects grip stregnth badly as it is a muscle relaxer

19
Q

Orexin receptor antagonists

A
  • Hypothalamus has orexin pathway which projects to locus coeruleus which promotes wakefulness
  • Antagonist will block this pathway

Suvorexant – dual orexin receptor antagonist –

Disease B (6 decks)

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