Brainscape's Knowledge GenomeTM

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


See full index

Phys/Pharm Drugs Of Abuse > Neuropharmacology And Drug Abuse > Flashcards

Neuropharmacology And Drug Abuse Flashcards

1
Q

Identify neuroanatomical regions involved in addiction and discuss their function (4)

A

image
Red= emotional connection + memory/learning

Yellow= Movement, Motivation, Habit formation (part of basal ganglia)

Green= Reward predication + pleasure

Blue = Motivation + value to reward

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

Dopamine neurotransmission normal vs w/drugs

A

image
Hijack this pathway = increased + more dopamine release

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

Stages in Addiction Cycle

A

images

reward pathway not stim. but suppressed, stress pathways activated

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

Stage 1: Acute Reinforcement

A

images
Acute effects of drugs - (Positive reinforcement)

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

Different acute targets for drugs of abuse (8)

A

Opioids - Agonist at mu (and delta and kappa) opioid receptors

Cocaine - Dopamine transporter blocker - indirect DA agonist

Amphetamine - Dopamine releaser - indirect DA agonist

Alcohol - Facilitates GABAA + inhibits NMDA receptor function

Nicotine - Agonist at nACh receptors

Cannabinoids - Agonist at CB1 receptors

Phencyclidine - NMDA receptor antagonist

Hallucinogens - 5-HT2A agonists

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

Amphetamine (psychostim.) - pharm effects, therapeutic uses, prolonged use (8)

A

drugs like amph. (methylphenidate & MDMA) release CYTOSOLIC MONOAMINES (DA)

Pharm effects:
- increased alertness and locomotor stimulation(inc. aggression)
- Euphoria / excitement
-Stereotyped behaviour
-Anorexia
- decreased physical and mental fatigue (improves monotonous tasks)
-Peripheral sympathomimetic actions (Peripheral sympathomimetic actions (inc. bp & dec. gastric motility)
-Confidence improves/lack of tiredness

Therapeutic uses:
-ADHD (methylphenidate), appetite suppressants, narcolepsy

Prolonged use neurotoxic
** Degeneration of amine-containing nerve terminals, cell death

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

Cocaine (central stim.) (6)

A

image
blocks catecholamine reuptake (inc. DA stim. effect)

Pharmacological effects:
-Euphoria
- Locomotor stimulation
** Fewer stereotyped behaviours than amphetamine
-Heightened pleasure
** Lower tendency for delusions, hallucinations and paranoia

Pharmacokinetics:
-HCl salt, inhaled and i.v. administration
** Nasal inhalation less intense, leads to necrosis of nasal mucosa
-Freebase form (‘crack’), smoked, as intense as i.v route

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

Psychotomimetics: MDMA (5)

A
  • Inhibits monoamine transporters (mainly 5-HT)
    ** Also releases 5-HT
    ** Large inc. 5-HT (followed by depletion)
    ** inc. 5-HT linked to psychotomimetic effects
    ** inc. DA linked to euphoria (followed by rebound dysphoria)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Opioids: Heroin

A
  • Opioids produce intense
    euphoria via acting on MOP
    –Diamorphine (heroin) high abuse
    potential
  • Tolerance: Seen within 12 – 24 hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Opioid Disinhibition Effect

A

images

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

General Depressants - MoA + pharm effects
Alcohol (8)

A

MoA:
1)Potentiates GABA-mediated inhibition

2)Inhibits presynaptic Ca2+ through voltage-gated channels
** Inhibits transmitter release

3)Disinhibits mesolimbic DAergic neurons (inc. reward)

4) Induces the release of endogenous opioid peptides
** Reward effect dec. by naltrexone (endogenous opioid involvement)

Pharmacological effects:
- Slurred speech, motor in-coordination, inc. self confidence
-euphoria
-Impaired cognitive and motor performance
-Higher levels linked to labile mood: euphoria and melancholy,
aggression + submission

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

Social Drugs: Nicotine / tobacco (4)

A

Highly addictive

Pharm effects:
- nAch receptors, alpha4Beta2 subtype: ** rec., ligand-gated cation channel (pre+post synap.), enhances transmitter release + neuronal excitability including opioid peptides
- Cortex + hippocampus (cog. function.) + ventral tegmental area (DA release + reward)
- inc. alertness, dec. irritability (dep. on dose + situ.)

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

mechanisms

A

images

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

Acute effect of drugs of abuse on HPA axis

A

image
Opioids INHIBITS HPA axis in humans
Cocaine ACTIVATES HPA axis

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

Stage 2: repetitive use/dependence/withdrawal

A

image

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

Withdrawal Syndrome effects (2)

A

-Physical, characterised by abstinence syndrome (LC)Physical, characterised by abstinence syndrome (LC)
** Sweating, gooseflesh (cold turkey), irritability, aggression

-Psychological, craving to avoid withdrawal effects

17
Q

Withdrawal Syndrome Drugs and effects (5)

A

-Psychostimulants: deep sleep, lethargy, depression, anxiety & hunger

  • MDMA (ecstacy):Depression, anxiety,irritability,
    incr. aggression
  • Heroin: Sweating, gooseflesh (cold turkey), irritability, aggression

-Nicotine: Irritability, hunger, weight gain, impaired cognitive + motor performance, craving (persisting many years)

-Alcohol: Tremor, nausea, sweating, fever, hallucinations
** Seizures, confusion, agitation, aggression

17
Q

Chronic effects of drugs: Mechanism of Dependence & Tolerance

A

diagram

18
Q

Mechanism of Dependence (NA)
(Homeostatic compensatory
neuroadaptation)

A

diagram

19
Q

Stages in addiction cycle
Wee & Koob (2010) Psychopharmcacol

A

images

20
Q

Mechanism of dependence (HPA) (5)

A
  • Heroin addicts have
    Hyporesponsivity HPA axis
  • Cocaine addicts have
    Hyperesponsivity HPA
  • CRF in extended Amygdala
    increased in withdrawal
  • CRF antagonist block withdrawal
    in animal models
  • CRF desregulation long lasting
    (tolerance kicks in)

images

21
Q

Mechanism of dependence (α4β2*)

A

Up-regulation of α4β2*

Rapid dev. of tolerance (desensitisation of nACh receptors)

22
Q

Relapse

A
  • Induced by drug priming, drug related cues, stress

info.

23
Q

addicted vs unaddicted brain

A

data, yin yang

24
Q

Regulation of CREB by addictive drugs

A

diagram,

25
Q

CREB (transcription factor)

A

Also change in FosB activation in withdrawal

26
Q

Role of dopamine in addiction (5)

A
  1. Intake of drugs of abuse leads to increase in dopamine in nucleus accumbens + other limbic regions
  2. Psychostimulants induce reward via a DA dependent mechanism
  3. D2 knockout mice show no effect on withdrawal symptoms of
    morphine after chronic administration
  4. Opiate and alcohol SA persists when DA projections are
    destroyed (DA independent mechanism)
  5. Nicotine activates dopaminergic system via nicotinic receptors
    VTA and Nacb

D2 antagonists are largely ineffective in drug addiction treatment

27
Q

Role of endogenous opioids in addiction (8)

A
  1. Mu agonists are reinforcing and cocaine reinforcement is
    modulated by opioid antagonists
  2. Mu antagonists are effective in limiting craving and relapse
  3. Injections of opioids into the VTA generate self-administration
  4. Mu opioids facilitate intracranial self stimulation
  5. Mu opioid receptor knockout mice show loss of addictive
    responses to opioids, alcohol, cannabinoids and nicotine
  6. Proenkephalin knockout mice show loss of addictive response
    to cannabinoids and nicotine
  7. Alcohol and nicotine induce the release of endogenous opioids
  8. Cocaine induces MOP and KOP upregulation which is
    persistent
28
Q

Role of GABA in addiction (6)

A
  1. Firing of dopaminergic neurones in VTA is inhibited by GABA interneurones
  2. Opioids indirectly remove this inhibition by presynaptic
    inhibition of GABA interneurones + responsible for the rewarding effects of opioids
  3. GABAB agonist (baclofen) reduces nicotine reward in humans
  4. Cannabinoids inhibit GABA release. Effects of cannabinoids
    mediated indirectly via opioid receptors
  5. GABA agonist in Amygdala decrease alcohol SA
  6. Chronic alcohol decreased GABA and increased NMDA
29
Q

Genetics and addiction (6)

A
  • Human approaches to identify “addiction genes”
    -Twin studies
    -Identification of SNPs in addicted individuals
    -Searching for abnormal mRNAs at autopsy
    -Genome-wide scans of addicted vs normal individuals
    -Genealogical approach and linkage analysis from genome-wide
    scan of families (in populations that are genetically homogeneous)
30
Q

e.g.’s of genes and addictions (7)

A
  • ADH + alcoholism
  • Ppdyn + cocaine addiction
  • GABAA2 subunit + alcoholism
  • A118G SNP (Asn to Asp) of MOP + heroin addiction
  • Low 5HT associated w/ impulsivity
  • Co morbidity genes
  • COMT association w/ alcoholism, heroin

Phys/Pharm Drugs Of Abuse (23 decks)

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