Cocaine and Amphetamines Flashcards
(42 cards)
What are drug free periods known as?
Remission ⇒ followed by relapse (aspect difficult to control)
What is substance use disorder?
- Maladaptive pattern of substance use for at least 12 months leadins to significant impairment or distress by clinical standards
What is the conditioned place preference test (CPP)?
(3 marks)
- Relies on conditioned association between drug effect and environment
- drug rewarding, stays within the environment associated with it
- drug aversive, stays within the other environment
What is the best way of measuring drug reinforcement?
Investigating HOW animl self administered the drug
How can you measure how an animal self administers a drug?
- Use infusion pump attatched to animal and can use lever to inject drug
- At higher doses, number of reinforcers can decline due to satiation, aversive reactions/ behaviourally disrupted side effect
How can you use progressive ratios to measure breaking point of animal?
(4 marks)
- Animal is trained to press lever with frequency ratio (FR) of 5 - drug every 5 responses
- Breaking point = number of responses animal is willing to do to get the drug
- Correlation between motivation of animal and addictive condition
- Breaking point is higher with higher motivation - increases with higher doses
How is relapsed modelled in self administration studies?
What does this show?
(3 marks)
- Deliver small dose of drug
- Subject animal to stress
- Put in environmental cues previously paired with drug delivery
People may be free of addiction for years but single dose can start it all over again
What is abstinence syndrome?
Attempts at abstience that lead to unpleasant withdrawal symptoms to motivate user to use the drug again
Assuming circuitry of VTA-NAc parallels that of SN-DS in basal ganglia system, what receptor class should be activated by psychostimulation of NAc-VTA to enhance locomotor function?
Dopamine D1
What is the reward circuit?
- Neural circuit responsible for acute rewarding and reinforcing affects of abused drugs
- Uses GABAA receptors and dopamine pathways
Which one is synthetic and which one is a natural compound:
Cocain or Amphetamines?
Cocaine - natural compound
Amphetamines - synthetic
What is cocaine?
(2 marks)
- Alkaloid
- Coca leaves used to relieve fatigue and maintain fitness at high altitudes
What two cocain drugs are used experimentally?
(2 marks)
- WIN 35,428 (aka CFT)
- RTI-55 (aka B-CIT)
What are some of the characteristics of Cocain HCl?
(3 marks)
Water soluble
Injected/orally digested
Normally snorted nasally
What methods are used to create crack cocaine?
(4 marks)
- Dissolve in water and add alkaline solution i.e. ammonia
- Extract cocaine base with organic solvent typically ether
- (Freebasing: refers to cocaine smoked in this manner)
- Mix dissolved HCl with baking soda, heat mixture then dry it
- Chunks of dry or hardened mixture known as ‘crack’ cocaine
What properties of cocaine allow it to be absorb very efficiently?
(2 marks)
Lipophilic - (fat soluble) readily passes through blood brain barrier
Smoking - undetectable in blood and goes straight to brain
Why does cocaine tend to be taken repeatedly throughout the day?
Very short half life
What breakdown product of cocaine is detectable in urine for several days?
Benzoylecgonine
What is created when you mix alcohol and cocaine?
Unique metabolite called cocathylene - longer half life and much stronger
Explain the mechanism of cocaine action.
(6 marks)
- Cocaine binds to transporters of DA, NE and serotonin (5-HT)
- Blocks transporter and increases time of NT in synaptic cleft and increases transmission
- Cocaine preferntially binds with high affinity to DAT transporter, followed by NE transporter and then 5-HT receptor
- Most action of cocaine exerted through dopamine transporter
- Remove transporter - lose most cocaine response
- At v high concentrations cocaine able to inhibit voltage gated Na+ hcannels in axons blocking nerve conduction
What are the effects of cocaine if applied locally?
Works as local anaesthetic by preventing transmission of signals along sensory nerves
What are the typical feelings of the high associated with cocaine?
Exhilaration and euphoria, enchanced alertness, may see increased aggresive behaviour
What did animal models show about the affects of low doses of cocaine?
- Increases locomotion, rearing and mild sniffing behaviour
What is meant when it is said that cocaine is ‘sympathomimetic’?
(3 marks)
- Can only work in post ganglionic synapses in sympathetic nervous system as it doesn’t use ACh it uses NE
- Produces sytems of sympathetic nervous activation
- Some responses if very abd are an example of cocaine infection