Brainscape's Knowledge GenomeTM

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


See full index

PSY325 - Neuropsychology & Clinical Neuroscience > Week Four - Addiction Neuroscience > Flashcards

Week Four - Addiction Neuroscience Flashcards

1
Q

What is the definition of addiction?

A

There is no single, universally accepted definition of addiction.

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

Why are there criticisms of addiction being a ‘brain disorder’?

A

Because it disregards human decision making and choice

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

What does the DSM-5 regard addiction as?

A

substance-related and addictive disorder

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

Substance-related disorders are classified into what 2 groups?

A

Substance use disorders

Substance-induced disorders

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

What do Substance use disorders involve?

A

Involve a cluster of cognitive, behavioural, and physiological symptoms as well as continued use of the substance despite significant substance-related problems.

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

Substance abuse disorder disorder contains what 9 classes of drugs?

A

alcohol, cannabis, hallucinogens, PCP, opioids, inhalants, sedatives, stimulants, or tobacco.

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

What do Substance-induced disorders include?

A

substance intoxication, substance withdrawal, and other substance/medication-induced mental disorders.

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

severity of substance-induced disorder depends on what?

A

How many criteria are met
2-3: mild
4-5: mod
6+: severe

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

What is the cause of of substance use disorders and addictive behaviour?

A

No single cause, but a product of enviro and physiological factors

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

Why are animal models ‘limited’ or criticised?

A

Because humans manipulate the addiction environments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does the drug cycle begin?

A

Positive reinforcement: pleasurable effects reinforce drug use

Negative reinforcement may also however explain initial drug use in those who use drugs to escape distress/stress

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

Why does compulsive drug-taking occur?

A

Because the rewarding effects of drug use are reduced and there is a need to achieve a state of homeostasis (neg reinforcement)

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

Addiction shares features of what 2 disorders?

A

Impulsive and compulsive

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

When does negative reinforcement occur during drug taking?

A

When drug taking is driven by the need to reduce anxiety/stress

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

A shift from pos to neg reinforcement is evident when?

A

An individual transits from an impulsive disorder to compulsive disorder

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

What is a common feature of all addictive drugs?

A

They activate reward pathways in the brain by triggering the release of dopamine

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

What do reward pathways refer to?

A

The connections between striatal, midbrain, limbic and prefrontal regions of the brain known as the mesocorticolimbic pathways

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

Where do drugs such as amphetamine, cocaine, nicotine and morphine as well as food and sex elevate dopamine transmission?

A

in the nucleus accumbens (heavily innervated by dopamine fibres)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do drugs create an illusion in the nucleus accumbens?

A

By creating an illusion and tricking the brain by imitating the release of chemicals associated with motivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Lesioning the dopamine system at the level of the nucleus accumbus does what?

A

prevents the acquisition of cocaine and nicotine self-administration in rodents suggesting that dopamine mediates the enforcing effects of each.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What further substantiates dopamines involvement in addiction - parkinson’s?

A

D agonists often block the rewarding effects of drugs.

Humans with PD report having blunted effects of stimulants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is drug addiction often characterised by?

A

Anhedonia (failure to experience rewarding stimuli)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

In addition to the dopamine system, the serotonergic system plays a critical role in what?

A

Mediating the experience of pleasure as evidenced by depression research

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What other 2 NT also play a role in addiction?

A

GABA

  • opiates increase dopamine in part by removing the inhibitory influence of GABA on dopamine releasing cells
  • GABA agonists have been found to reduce drinking, decrease craving ad improve sleep in those with alc use disorder

GLUTAMATE
- low glutamate levels in peeps with alc use disorder

25
Q

Addiction leads to changes in (5)

A

synaptic plasticity

dendritic size and spines

white and gray matter

up/down-regulation of receptors

intracellular signalling pathways

26
Q

What is synaptic plasticity?

A

The ability of synaptic connections to strengthen or weaken as a result of increased or decreased activity

27
Q

What two receptions have received attention in SP?

A

NMDA and AMPA glutamate receptors

28
Q

NMDA and AMPA glutamate receptors are typically involed in what?

A

long-term potentiation

29
Q

What is LTP?

A

LTP refers to increased efficiency of neurotransmission and plays a critical role in learning and memory.

30
Q

Changes in SP are observed in what?

A

Drug sensitisation (an enhanced response to the drug that is observed following repeated exposure; also known as reversed tolerance)

31
Q

What did amphetamine treatment do to mices dendritic arbours/spines?

A

It increased the size of the in the nucleus accumbens and increased the number of spines these neurons had on their dendrites

32
Q

What was elevated in animals treated with amphetamine?

What did this demonstrate?

A

The number of glutamatergic synapses in the nucleus accumbens.

This region of the brain becomes hyper-excitable following chronic amphetamine exposure

33
Q

Robinson et al. (2001) found structural changes in dendrites located in the prefrontal cortex of rats that self-administered cocaine. What were these changes?

A

The dendrites of cells of the rats that self-administered cocaine were misshapen, with large, bulbous structures at their tips. - linked to impaired decision making and judgement

34
Q

Current technology does not enable what?

A

Dendritic density and size measurements in humans

35
Q

Studies have consistently reported what in regard to grey matter and substance use disorders? (2)

A

Gray matter volume reductions in the prefrontal regions and additional mesocorticolimbic structures.

Drug craving was negatively associated with gray-matter volume

36
Q

White matter and substance use disorder findings? (2)

A

Reduced white matter has been found in participants with substance use disorders.

Significant loss of cerebral white matter found in postmortem and living individuals with alcohol use disorder

37
Q

Rivkin et al. (2008) reported that children exposed to cocaine, tobacco, marijuana, or alcohol in utero had what?

A

Smaller head circumference and white and gray matter

38
Q

Opioid use disorder is associated with changes to what?

A

White matter and gray matter changes in brain regions implicated in addiction including those involved in the regulation of impulse control, as well as in reward and motivational functions

39
Q

Several studies have found what in regard to receptor regulation? Volkow and colleagues (1996)

A

Decreased density of postsynaptic dopamine receptors (D2) in participants with substance use disorder

40
Q

Chang, Alicata, and Volkow (2007) found reduced dopamine transporter density and reduced dopamine D2 receptors in what area of the brain?

A

The striatum

41
Q

Continued use of substances is associated with what?

A

Continued use is associated with complex intracellular changes.

42
Q

Intracellular changes are believed to be responsible for?

A

Tolerance, addiction and withdrawal

43
Q

What is one important intracellular change associated with drug addiction?

A

up-regulation of the (cAMP) pathway.

44
Q

What is CREB?

A

A protein that plays a key role in learning and memory.

45
Q

When is CREB induced?

A

Following chronic exposure to drugs such as stimulants and opiates.

46
Q

An increase in phosphorylated CREB correlates with what?

A

Diminished sensitivity to drug-induced reward.

47
Q

How is CREB linked with tolerance/dysphoria/withdrawal?

A

CREB provides a compensatory mechanism that responds to drugs

48
Q

Over-expression of ΔFosB does what?

A

increases sensitivity to the rewarding and reinforcing effects of stimulants

49
Q

What does the raclopride method allow?

A

Estimation of dopamine levels through competitive binding to D2 receptors

50
Q

After Methylphenidate-induced increases in the striatal dopamine in controls and in detoxified cocaine abusers what happens?

A

Cocaine abusers and alcoholics show decreased dopamine increases and report reduced reward effects of MP

51
Q

What can drugs cause?

A

Hypodopaminergia

52
Q

What is Hypodopaminergia

A

depletion of monoamine stores in the brain, inducing depressive-like symptoms

53
Q

What is Hypodopaminergia linked to? (2)

A

Anhedonia: inability or difficulty to experience pleasure

Hypofrontality: decrease activation of PFC - compromising planning/decision making

54
Q

What is a challenge for neurobiology?

A

To understand why some individuals become addicted while others do not

55
Q

What is a key to the current challenge for neurobiology? How?

A

Differences in reward circuits

Subjects with high d2 receptors = effects of MP not pleasant

Subjects with low d2 receptors = MP effects are pleasant

56
Q

Overexpression of D2 receptors in the NAcb in rats did what?

A

Reduces alcohol preference and self-administration

57
Q

Impulsive rats were found to have what?

A

Lower D2 receptors

58
Q

In humans, low densities of D2 receptors were associated with?

A

Decreased metabolism in the orbitofrontal cortex - associated with OCD and impulsivity

PSY325 - Neuropsychology & Clinical Neuroscience (12 decks)

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