Chapter 6 Flashcards
T/F developing therapeutic drugs for brain disorders that penetrate the blood brain barrier is a challenge
T
What % of drugs that could have therapeutic use cannot pass the BBB
98%
T/F Addictive drugs play on the natural function of the brain
T
How does addiction use the reward-seeking pathway of the brain
Naturally, when behaviours have desirable outcomes, the brain tells us we want to repeat this behaviour. This has a survival aspect, such as eating and sleeping
what NT system is related to reward-seeking behaviour?
Dopaminergic
What part of the brain releases dopamine during rewarding behaviours?
Nucleus Accumebens in the Mesolimbic pathway
What part of the brain is a part of learned pattern/ conditioned movement which are rewarding?
Substantia Nigra in the Nigrostriatal pathway
What type of behaviour releases the strongest amount of dopamine
Behaviours that we can predict
- ex: high dopamine when taking out cigarette and when smoking
Are the mesolimbic and nigrostriatal pathway connected?
Yes, projections allow connection between the movement and experience of reward
What is the reward center of the brain?
Nucleus Accumbens
What part of the brain releases dopamine in expectation of and during rewarding behaviours?
Nucleus Accumbens
What part of the brain is involved in routine movement?
Striatum
Limbic system
responsible for emotional experiences and memory of experiences
T/F The limbic system is responsible for physiological addiction
F - psychological
T/F The amygdala, the hippocampus and the thalamus are a part of the limbic system
F - not the thalamus
What area of the brain is responsible for reasoning and planning?
prefrontal cortex
What part of the brain is not functioning properly when a drug addict is unable to inhibit destructive behaviours?
prefrontal cortex
T/F Over the time of an experience, the rewarding aspect dissipates
T
What are the 2 types of tolerance
functional and metabolic tolerance
functional tolerance
less effect of drugs due to less effect at a synaptic level
metabolic tolerance
less effect of drug due to changes in how the body breaks down and expels the drug
T/F Once tolerance has been built, it is not possible to return to baseline levels of drug effect
F - can go back when repeated use stops
What organ is responsible for eliminating drugs
the liver, which metabolizes drugs
Sensitization
The strongest experience a person will have with a drug is the first time it is taken, and if taken rarely, will continue to have strong experiences
T/F the most dangerous situation is when heavy drug users return to drug use after a long break as tolerance for the drug is much lower than they think
True
Withdrawal symptoms are usually _______ of the drug experience
the opposite
T/F The severity of withdrawal symptoms is dependent on the person taking the drugs
F - depends on the drug
What system is involved in the memories of drug experiences that produce psychological drug cravings?
Limbic system
What basic system does drug addiction play on
The reward system and the role of reinforcement
What is the positive and negative reinforcement involved in drug addiction
Positive: the good feeling from taking the drug
Negative: the avoidance of withdrawal by taking the drug
T/F Drugs that work on the reinforcement system tend to be the most addictive
T
What speed and rate of absorption are the most addictive
Fast working and fast wearing off
Johnny has tried Drug A, which got him high immediately and wore off quick, and Drug B which took about an hour to kick in. Which is he more likely to become addicted to? Why?
Drug A because there is a stronger connection between the action of taking the drug and the effect. It also wears off quicker, making him want more sooner.
Incentive sensitization
other environmental cues that remind users of the drug experience and add to psychological dependence
(ex: being at a bar or drug house)
Repeated drug use alters ________ in the reward pathway
gene transcription factors
what is the epigenetic mechanism of addiction?
repeated use changes the reward pathway, leading to an addictive brain
T/F Addictive drugs are usually agonists
T
Benzodiazepines
minor sedatives and anti-anxiety agents
T/F Alcohol is a sedative drug
True
What can happen to benzodiazepine tolerance if someone is an alcoholic?
They may have a high tolerance to Benzo’s because they share a binding sight - this is called cross tolerance
Why is dangerous to mix alcohol and sleep drugs
Because they work on the same binding site which exacerbates the effects and increases the chance of overdose
What ion flows into the cell through GABA binding sites for sedatives?
Cl- which hyperpolarizes the cell and makes it less likely to fire, slowing brain activity
What receptor is altered in alcoholics
Gaba receptors
What are the withdrawal symptoms of alcohol
anxiety, convulsions, seizures
T/F The withdrawal symptoms of sedatives are more dangerous than that of excitatory drugs
True
What two NT systems are involved in THC use
dopaminergic and GABAergic
What are dissociative anesthetics
date rape drugs
GHB
a dissociative anesthetic in the form of salt, which causes dizziness and sleep
Ketamine
A dissociative anesthetic causing out of body experiences and lack of control over movement
Hallucination
visual or auditory experiences that are not real
Delusions
Bizarre thoughts about reality
Psychosis
checking out of reality
What was the first antipsychotic drug used for schizophrenia
Chlorpromazine
what was the original intent for chlorpromazine
to be used as a general anesthetic, but only calmed and did not put to sleep
first generation antipsychotics
dopamine antagonists
dopamine hypothesis of Schizophrenia
the first dominant theory about the cause of schizophrenia due to the effectiveness of dopamine agonist drugs
side effects of first generation antipsychotics
Tardive dyskinesia: repeated movements
Anhedonia: inability to experience pleasure
why was compliance difficult with first generation antipsychotics
the side effects were so unpleasant
Second generation antipsychotics
act on dopamine (less agonistic) and serotonin (for hallucinations) receptors
first generation antidepressants
MAO inhibitors and tricyclic antidepressants
MAO inhibitors
antidepressant which inhibits break down of serotonin (agonist)
Tricyclic Antidepressant side effects
can elevate blood pressure
Second generation antidepressants
SSRI’s, SNRI’s and ketamine
SSRI
Selective serotonin reuptake inhibitors - inhibits reuptake
SNRI’s
Selective Neurotransmitter reuptake inhibitors - inhibits reuptake of norepinephrine as well (which increases energy levels)
T/F SSRI’s and SNRI’s can be complicated to start because they take weeks before any effects are noticed
True
Ketamine as an antidepressant
In low doses, works quickly
What is one important area of the brain where neurogenesis continues throughout life
the hippocampus, which helps with the creation of new memories
T/F With depression, there is increased neurogenesis
F - decreased
what is the link between SSRI’s and neurogenesis
the timeline for SSRI’s to begin working lines up with the timeline of neurogenesis, and neurogenesis is increased to normal levels on SSRI’s
Opioid analgesics
pain relieving medications with a natural source from the opium poppy
Morphine
A synthetic analgesic made from active ingredient in opium
Heroin
A synthetic derivative opioid with a shorter half life (wears off faster) and twice the potency of morphine
Fentanyl
Opioid Analgesic with extremely high potency and rapid absorption across the BBB (high risk of OD)
Withdrawal symptoms of opioid analgesics
Allodynia: pain or irritation within the body with no obvious reason for it
Myoclonic movements: sudden jerking movements, fidgeting
What is the cause of OD with opioids
respiratory suppression
Naloxone
A drug that reverses OD within seconds but results in immediate extreme withdrawal
What are opioids mechanism of action
opioids bind to G-coupled endorphin receptors and create effects
what are the 3 mechanisms of tolerance to opioids
Desensitization: receptors become less sensitive
Endocytosis: receptor proteins sink into membrane and are less exposed for binding
Downregulation: loss of receptors which sink all the way in and are unable to bind
what is the primary NT for stimulants
Dopamine (agonists)
General stimulants
drugs that cause general increase in metabolic activity (increase energy levels)
Which of the following is not a stimulant
- Caffeine
- Alcohol
- ADHD meds
- Nicotine
Alcohol is a sedative
Why is a gradual decrease of cigarettes not a successful way quitting
Heavy smokers are very sensitive to changes in nicotine content and experience withdrawal easily
Nicotine withdrawal symptoms
trouble focusing, fidgeting
what method of quitting smoking is the most successful
The patch
Why is cocaine so highly addictive
rapid rate of absorption and tolerance
Consumption of what other drug increase the effects of cocaine
Alcohol, as byproducts of metabolism interact
What are the sex differences with cocaine
Cocaine is more intense in all aspects for women due to estrogen
How does methamphetamine create it’s effect at a synaptic level
increases the release of dopamine and blocks reuptake
Effects of methamphetamine
elevated mood, energy and alertness
Psychosis and hallucinations with high doses
What area of the brain shows deficits and volume loss with chronic meth use
hippocampus (memory deficits)
Why is MDMA less addictive than meth
It has a slower absorption rate and lasts longer
Who discovered LSD
Albert Hofmann
How do hallucinogens create their effects on a synaptic level
agonist to serotonin and norepinephrine (think opposite of antipsychotics)
What are the addiction rates for hallucinogens
very low and non-toxic
What was attempted through the LSD clinical trials in Saskatchewan
attempt to cure alcoholism through profound “awakening” but did not work
