Recreational Drug

Question 1

name examples of:

• opioids
• stimulants
• CNS depressants
• psychotomimetics

Answer 1

• morphine, codeine
• cocaine, MDMA (ecstasy)
• barbiturates, alcohol
• cannabis, lysergic acid diethyl amide (LSD)

Question 2

which neurotransmitters does cocaine target?

Answer 2

dopaminergic pathway it is a DA transporter antagonist

Question 3

which pathway in the brain activates in dependence-inducing drugs, describe this pathway

Answer 3

mesolimbic dopaminergic pathway from ventral tegmental area (VTA) to nucleus accumbens (NA)

Question 4

how does drugs increase dopamine transmission in the nucleus accumbens (NA)?

Answer 4

• decreased GAAergic inhibition in VTA
• increased DA release
• decreed DA reuptake

Question 5

what are the two drugs derived from the latex of opium poppy seedpod?

Answer 5

morphine and codeine

Question 6

what type of receptors are opioids receptors?

Answer 6

inhibitory GPCR

Question 7

two drugs that are used to treat opioid withdrawal syndrome and explain their mechanism of action

Answer 7

methadone:

• synthetic opioid with longer-half life than morphine
• stabilise heroin users
• long-lasting withdrawal occurs but less intense

naltrexone:
-opiate antagonist can help recovering addicts from relapsing by preventing rewarding effects

Question 8

describe the mechanism of action of cocaine

Answer 8

-cocaine blocks DA transporter increasing DA conc. in the synaptic cleft which results in over activation of DA receptor

Question 9

describe the mechanism of action of amphetamines

Answer 9

increase synaptic dopamine and noradrenaline via blocking transporters and reverse transport from pre-synaptic terminals

Question 10

describe the mechanism of action of nicotine

Answer 10

agonist at nAchR (ligand-gated ion channels)

Question 11

explain how nicotine works in the rewarding pathway

Answer 11

nicotine binds to nAchR in DA neurones and activates it -> Ca2+ influx and action potential generated in post synaptic neurones -> DA neurones release more DA which acts on its receptor

Question 12

which receptors is alcohol acting on and what is its effect on these receptors?

Answer 12

• increases GABA-A receptor activity -inhibitory

- acts as NMDA receptor antagonist

Question 13

name the active ingredient in cannabis.

which receptor is it acting on and what is its effect?

Answer 13

tetrahydrocannabinol (THC)

activation of CB1 receptor - a Gi/o coupled receptor which decrease GABA release and thereby indirectly increases dopamine

Question 14

what is another consequences of long-term use of recreational drugs?

Answer 14

long tern changes in TF which leads to changes in gene expression following chronic drug use

Question 15

what kind of compounds activate the serotonin (5-HT) pathway? what is the function of this pathway?

Answer 15

• commonly activated by hallucinogenic compounds

functions:

• mood
• memory processing
• sleep
• cognition

Question 16

which receptor doe MDMA (ecstasy) block?

Answer 16

• blocks serotonin transporters thereby increasing serotonin concentration in the cleft also affects dopamine and noradrenaline transporters

Question 17

what is the mechanism of action of lysergic acid diethyl amide (LSD) and what does it cause?

Answer 17

causes:

• distorted perception
• hallucinations

agonist at 5-HT receptors (5-HT2A)

inhibits firing of 5-HT neurones in raphe nuclei by activating inhibitory auto receptors:
- 5HT2A subtype -> Gq protein -> activates PLC -> IP3 and diacylglycerol (DAG) production