Sleep and hypnotics

Question 1

What is sleep?

Answer 1

A readily reversible state of reduced responsiveness to, and interaction with, the environment.

Question 2

What are the functions of sleep?

Answer 2

Restoring - rest, relaxation and repair, adaptation (protection from nocturnal predators), energy conservation and memory consolidation and integration.

Question 3

What is an EEG?

Answer 3

An electroencephalogram -it records the activity of populations of neurones. It reveals synchrony of neuronal activity.

Question 4

What does frequency in an EEG show?

Answer 4

How fast neurones are firing.

Question 5

What does amplitude power) reflect in an EEG?

Answer 5

The number of neurones that are in synchrony.

Question 6

What are the 5 different frequencies representing brain rhythms and functional states?

Answer 6

Delta, theta, alpha, beta and gamma.

Question 7

What is the delta brain rhythm?

Answer 7

Deep, dreamless sleep.

Question 8

What is the theta brain rhythm?

Answer 8

Light sleep - dreaming, mental imagery, meditation and memory.

Question 9

What is the alpha brain rhythm?

Answer 9

Conscious relaxation, mental visualisation.

Question 10

What is the beta brain rhythm?

Answer 10

Awake, alert, concentration, cognition, motor activity and navigation.

Question 11

What is the gamma brain rhythm?

Answer 11

Memory encoding and recall, attention, predictions and cognitive processing.

Question 12

What is the difference between REM and non-REM?

Answer 12

non-REM is a deeper sleep that is not associated with dreaming, whereas REM is less of a deep sleep and is associated with dreams.

Question 13

What is the pattern of REM and non-REM sleep?

Answer 13

There are alternate periods of REM and non-REM, with each cycle having shorter and shallower non-REM periods and longer REM periods.

Question 14

How long are the cycles of REM?

Answer 14

20-40 minutes.

Question 15

How long are cycles of non-REM?

Answer 15

60-90 minutes.

Question 16

What is the reticular activating system?

Answer 16

It is an area responsible for regulating wakefulness and sleep-wake transitions.

Question 17

What happens if the reticular activating system is lesioned?

Answer 17

Coma and sleep.

Question 18

What happens if the reticular activating system is stimulated?

Answer 18

Wakefulness.

Question 19

What happens if the thalamus is stimulated?

Answer 19

The patient will fall asleep.

Question 20

What hormones/neurones contribute to sleep cycles?

Answer 20

Orexin neurones, cholingergic, serotonergic, noradrenergic, histamine neurones.

Question 21

What are the interactions between RAS, thalamus and cortex in an awake state?

Answer 21

The RAS activates the thalamus and the thalamus generates non-rhythmic activity. The cortex is then entrained into fast waking activity.

Question 22

What are the interactions between RAS, thalamus and cortex in an asleep state?

Answer 22

The RAS activity is switched off and the thalamus generates rhythmic activity, and the cortex is entrained into slow sleep rhythms.

Question 23

How does the activity of brainstem neurons change from REM to non-REM sleep?

Answer 23

Non-REM sleep has decreased activity, whereas in REM sleep they are completely inactive (raphe nuclei and locus coeruleus).

Question 24

What is transient insomnia?

Answer 24

Lack of sleep due to noise, shift work and jetlag.

Question 25

What can cause short term insomnia?

Answer 25

Emotional issues, stress and anxiety.

Question 26

What can cause chronic insomnia?

Answer 26

Pain, depression, alcohol abuse and breathing disorders.

Question 27

What is fatal familial insomnia?

Answer 27

A rare prion disease that causes initially mild insomnia, that can develop severely and lead to physical and mental deterioration.

Question 28

What are hypnotics?

Answer 28

Psychoactive drugs that induce sleep.

Question 29

What is the action of hypnotics?

Answer 29

They potentiate GABA inhibition by enhancing GABAa receptors.

Question 30

What is the name for common hypnotics?

Answer 30

Benzodiazepines.

Question 31

What are the problems with hypnotics?

Answer 31

There are problems with tolerance and dependence and rebound insomnia.

Question 32

What are the benefits of non-benzodiazepine hypnotics?

Answer 32

They may have subunit specificity, meaning there are potentially less side effects.

Question 33

What are some other potential hypnotics?

Answer 33

Orexin antagonists, histamine H1 antagonists, gamma-hydroxybutyrate and melatonin receptor agonists.

Question 34

What is narcolepsy?

Answer 34

A pathological increase in sleep. There is a sudden onset of sleep episodes and loss of motor control.

Question 35

What are the treatments for narcolepsy?

Answer 35

Stimulant drugs such as modafinil and methylphenidate.

Question 36

What are some examples of long acting benzodiazepines?

Answer 36

Nitraxepam, flurazepam.

Question 37

What are some examples of short acting benzodiazepines?

Answer 37

Loprazelam, temazepam, flunitrazepam.

Question 38

What are some problems with benzodiazepines?

Answer 38

Issues with tolerance and dependence and rebound insomnia.

Question 39

What are some examples of non-benzodiazepine hypnotics?

Answer 39

Zolpidem, eszoplicone, zalepion.

Question 40

What are some benefits of non-benzodiazepine hypnotics?

Answer 40

They may have less sub-unit specifity and may have less side effects.

Question 41

What are some barbiturate and barbirutate-like hypnotics?

Answer 41

Phenobarbitone, methaqualone, meprobamate. They are rarely used now.

Question 42

Give an example of an orexin antagonist.

Answer 42

Suvorexant.

Question 43

Give an example of Histamine H1 antagonists.

Answer 43

Diphenhydramine, chlorpheniramine.

Question 44

What is an example of a melatonin receptor agonist?

Answer 44

Melatonin, ramelton.

Question 45

What is gamma-hydroxybutyrate?

Answer 45

A naturally occurring drug that may be a GABAB agonist or metabolised to GABA.

Question 46

What can melatonin receptor agonists be used for?

Answer 46

Resetting disturbed circadian rhythms - due to jet lag or shift work patterns.