Drugs of Dependence and Antidepressants Flashcards Preview

MD1 Neuroscience > Drugs of Dependence and Antidepressants > Flashcards

Flashcards in Drugs of Dependence and Antidepressants Deck (95):
1

What is drug dependence?

Drug taking becomes compulsive
Takes precedence over other needs

2

What is drug abuse?

Use of illicit substances or illicit use of legal substances
Recurrent and clinically significant adverse consequences

3

What contributes to psychological dependence?

Rewarding effect of psychoactive drug

4

What is the rewarding effect of the psychoactive drug?

Positive reinforcement > desire to continue experience

5

Does the rewarding effect only happen with drugs?

No, it can happen with any activity

6

What contributes to physical dependence?

Habituation/adaptation

7

What is habituation/adaptation?

Feeling normal/aversion of negative symptoms
Don't take drug to feel good but not to feel bad

8

What are the reward and salience circuits involved in drug abuse and addiction?

Nucleus accumbens
Ventral pallidum

9

What are the memory and learning circuits involved in drug abuse and addiction?

Hippocampusw
Amygdala

10

What are the motivational drive circuits involved in drug abuse and addiction?

Orbitofrontal cortex
Subcallosal cortex

11

What are the inhibitory control circuits involved in drug abuse and addiction?

Prefrontal cortex
Anterior cingulate gyrus

12

What happens to the inhibitory control circuits in drug abuse and addiction?

Removed to elicit excitation

13

Which circuits have interplay between them in drug abuse and addiction?

Those for reward and salience, and memory and learning

14

Which neurotransmitter is implicated in reward pathways, and how?

Increased dopamine in nucleus accumbens

15

What are the key transmitters modulating dopaminergic transmission?

Atch
Serotonin
NA
GABA
Glutamate
Opioids

16

Which neurotransmitters are targeted by most of the drugs that are used and abused?

Those that modulate dopaminergic transmission

17

Describe the dose-response curve in the CNS

Bell-shaped rather than sigmoid

18

What effects did cocaine have on people with high dopamine receptor levels?

Aversive effects

19

What effects did cocaine have on people with low dopamine receptor levels?

Pleasant effects

20

Do receptor levels change, and if so, what do they change in response to?

Yes, change in response to
- Time
- Disease
- Drug taking

21

How do some tolerance mechanisms work when receptors are involved?

Receptor levels are too high, so with extended drug use, they've been downregulated

22

What are two examples of opioids?

Morphine
Heroin

23

What are the CNS effects of opioids?

Euphoria

24

What are two examples of CNS depressants?

Alcohol
Diazepam

25

What are the CNS effects of CNS depressants?

Reduced anxiety

26

What are three examples of CNS stimulants?

Cocaine
Amphetamine
MDMA

27

What are the CNS effects of CNS stimulants?

Excitement
Euphoria
Reduce fatigue

28

What is an example of an hallucinogen?

LSD

29

What are the CNS effects of hallucinogens?

Altered perception

30

What is an example of a cannabinoid?

D-9-THC

31

What are the CNS effects of cannabinoids?

Altered perception

32

What is non-therapeutic drug use?

Consumption by choice not medical advice

33

What are the specific effects of CNS stimulants on CNS transmission>

NA, dopamine, and serotonin to various degrees

34

What does cocaine do at the synapse?

Block neuronal uptake of NA

35

What does amphetamine do at the synapse?

Utilises uptake carrier for NA to enter pre-synaptic terminal
Displaces NA from synaptic terminal

36

What effect do cocaine and amphetamine have on NA at the synapse?

Increase NA levels in synaptic cleft

37

Which neurotransmitters are predominantly affected in the CNS by cocaine and amphetamine?

Dopamine
Serotonin

38

Which neurotransmitters does amphetamine release in the CNS?

Predominantly NA and dopamine
Also serotonin

39

With what do the effects of amphetamine vary?

Mood
Personality
Environment

40

What are the CNS effects of amphetamine?

Mood elevation and euphoria
Increase locomotor activity
Stereotypic behaviour

41

What effects does amphetamine have on physical and mental performance?

Fatigue postponed
Confident and speedy performance, but less accurate

42

What is the possible mechanism for the appetite suppressant activity of amphetamine?

Serotonin effect

43

What is a medical application of amphetamine?

Analogues used for ADHD

44

Does amphetamine induce tolerance?

Yes, need larger dose for same effect with long term use

45

What is the mechanism by which amphetamine induces tolerance?

Downregulation of receptors over time

46

Does amphetamine cause psychological dependence?

Yes, but not as marked as cocaine

47

Which group of people are more susceptible to amphetamine dependence?

Depressives
Lonely people

48

What are the physical withdrawal symptoms of amphetamine?

Lethargy
Sleep
Desire for food
Depression

49

What does chronic use or an overdose with amphetamine cause?

Anxiety
Nervousness
Physically tension
Tremors
Confusion
Dizziness
Time passes quickly
Hyperthermia
Tachycardia
Increased BP
Vascular collapse > death
Psychosis - hallucinations

50

Compared to amphetamines, what neurotransmitters do cocaine and MDMA targeet?

Target same ones but cocaine and MDMA have relative selectivity for dopamine, serotonin and NA

51

What are the cognitive effects of caffeine?

Increases alertness and well being
No euphoria
Delays onset of sleep

52

In what ways does caffeine stimulate mental activity?

Postpones boredom, fatigue, and inattentiveness
Enhanced intellectual and motor performance

53

What do high doses of caffeine cause?

Anxiety
Tension
Tremors

54

What is the drug class of caffeine?

Methylxanthine

55

What are the targets of caffeine?

Predominantly an adenosine antagonist
Phosphodiesterase inhibitor > cAMP not broken down
By targeting 2nd messengers, it affects transmission beyond NA, DA and 5-HT

56

Does caffeine cause dependence?

Not strongly in animals or humans
Reinforcing behaviour linked with social aspect

57

What is a withdrawal symptom of caffeine dependence?

Headache

58

What sort of hallucinations does LSD cause?

Visual
Auditory
Tactile
- Sensory modalities get confused

59

What happens to your thought processes whilst on LSD?

Disturbed but aware drug-induced

60

Does LSD cause dependence?

Could be aversive rather than reinforcing some people - "bad trip"

61

How is tolerance to LSD mediated?

Receptor mediated

62

How fast does tolerance to LSD happen?

Quickly

63

What happens when you take LSD with other psychotomimetics?

Effects impaired by cross tolerance

64

What is the target of LSD?

In CNS agonist at 5-HT2 receptor
Causes inhibition of 5-HT neurons in Raphe

65

What neurotransmitters does MDMA/ecstacy release?

Dopamine and serotonin

66

What are the effects of MDMA?

Stimulant and hallucinogenic effects

67

Is MDMA as effective as amphetamine or LSD?

No

68

What cognitive effects does MDMA have?

Feeling of closeness
Empathy
Love
Heightened self-awareness

69

Does MDMA cause dependence?

Yes because of rewarding reinforcing effect

70

What are the effects of MDMA on the cardiovasular system?

Increases HR
Increases BP

71

What effect does MDMA have on thermoregulation?

Disrupts it - causes chills and sweating

72

What is the effect of the active metabolites of MDMA on the brain?

Potential degeneration of 5-HT and DA neurons
Affects
- Mood
- Memory
- Sleep
- Appetite

73

What effect do CNS depressants have?

Relaxation
Sense of well being

74

What are two forms of cannabis that are often taken?

Marijuana
- Dried leaves
- Flower heads
Hashish
- Extracted resin

75

What is the active component in cannabis?

D9-THC

76

What are the cognitive effects of D9-THC?

Relaxation
Feeling of well being
Sharpened sensory awareness - increased intensity of sounds and sights

77

What influences the effects of D9-THC?

Characteristics of drug
Individual

78

What are the cannabinoid receptors to which D9-THC binds?

CNS - CB1
PNS - CB2

79

What type of receptors are CB1 and CB2, and what effect do they have when they're activated?

GPCRs
Inhibition of adenylate cyclase > inhibition of transmission

80

Which other drug can possibly interact with D9-THC?

Caffeine

81

What is anandamide?

Endogenous cannabinoid receptor agonist
Unknown physiological role

82

What is nabilone?

Synthetic cannabinoid analogue
Being developed as anti-emetic

83

What is the effect of cannabinoids on neurotransmitters?

Increase dopamine neuronal firing by decreasing GABAergic inhibition of dopamine neural activity

84

What are the central effects of D9-THC?

Impaired short term memory
Impaired motor coordination
Catalepsy
Analgesia
Anti-emetic
Increased appetite

85

What are the peripheral effects of D9-THC?

Tachycardia
Vasodilation
Reduced intraocular pressure
Bronchodilation

86

Does D9-THC cause dependence?

Some evidence of physical and psychological dependence in heavy users

87

What are the effects of ethanol on the neuron?

Inhibit Ca channel opening > stop exocytosis
Enhance GABA action and glycine mediated inhibition
- GABA-A receptors
- Reversal by Flumazenil
Opens some K channels > cell hyperpolarises
Inhibits glutamate receptors
- NMDA channel

88

How does ethanol bind to the GABA-A receptor?

Binds in lipid membrane
Changes shape of receptor
Increases GABA binding

89

What are the behavioural effects of ethanol?

Subjective
- Increased self confidence
- Euphoria
- Usually loud and outgoing
- Less often morose and withdrawn
- At higher doses aggression and mood swings

90

What are the motor effects of ethanol?

Loss of motor coordination
Slurred speech

91

What are the tissue effects of ethanol?

Liver damage
Neurodegeneration
Foetal impairment

92

What is the mechanism of tolerance of ethanol?

Pharmacokinetic mechanism - enhanced clearance

93

What are the behavioural signs of ethanol withdrawal?

Anxiety
Insomnia
Nausea
Anorexia
Delusions
Hallucinations

94

What are the neurological signs of ethanol withdrawal?

Tremor
Hyperactive reflexes
Agitation
Delirium
Convulsions
Status epilepticus

95

What are some physical signs of ethanol withdrawal?

Vomiting
Postural hypotension
Sweating
Hyperpyrexia

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