bio lec 3 Flashcards
What are psychoactive drugs?
Chemicals that influence emotions, behavior, and cognition.
What is pharmacokinetics?
How drugs move through the body.
What are the mechanisms by which drugs interact with the body?
- Inhibit or reinforce enzyme activity
- Block or activate receptors
- Interact with neurotransmitters or hormones
- Attack invaders (e.g., antibiotics)
What is the difference between agonists and antagonists?
- Agonists → Mimic neurotransmitters
- Antagonists → Block neurotransmitter effects
agonis=actor
What is the function of auto receptors?
They sit at presynaptic membrane and create a negative feedback loop for neurotransmitter release.
What is the slowest route of drug administration?
Digestive tract (oral).
What is the blood-brain barrier?
A specialized filtering system that protects the brain from toxins.
What are the two reasons drugs are eliminated from the body?
- Chemical breakdown (enzymes)
- Excretion (urine, sweat, breath)
What is biological half-life?
The time it takes for peak concentration of a drug to decrease to half in the bloodstream.
What is drug tolerance?
A shift in the drug effect curve requiring higher doses for the same effect.
What are the two types of drug tolerance?
- Metabolic Tolerance → Body eliminates drug more efficiently
- Functional Tolerance → Brain adjusts receptor numbers and sensitivity
What happens during withdrawal?
The body experiences symptoms due to the absence of a drug it has adapted to.
True or False: Context-dependent tolerance can affect drug use.
True.
What is operant conditioning?
A stimulus triggers a behavior that leads to a reward, reinforcing the behavior.
What areas of the brain are involved in addiction?
- Ventral Tegmental Area (VTA)- dopamine-producing
- Nucleus Accumbens- recieves dopamine, pleasure centre
- Medial forebrain bundle- conects the 2
What neurotransmitter is primarily involved in the brain’s reward system?
Dopamine.
What is the seeking or wanting hypothesis regarding dopamine?
Dopamine is more about motivation to seek something pleasuring rather than pleasure itself
What is psychological drug dependence?
When drugs directly interact with the brain’s reward system.
Fill in the blank: The __________ is a system that connects the midbrain to the endbrain using dopamine as its neurotransmitter.
Mesotelencephalic Dopamine System.
What can increase the risk of overdose when using drugs?
Using drugs in new settings without prior conditioning.
What is the relationship between dopamine and punishment?
Dopamine is also released during punishment to reinforce learning not to perform certain behaviors.
What happens to dopamine levels when a reward is expected?
Dopamine levels increase.
What is the role of dopamine in the reinforcement system?
It correlates with reward and motivates the repetition of behaviors.
What system in the brain is directly interacted with by drugs, causing cravings?
The brain’s reward system
This interaction leads to cravings for drugs even when the addict dislikes their effects.
What effect does cocaine have on dopamine levels?
Cocaine increases dopamine levels, making it highly addictive
The increase in dopamine is linked to the drug’s addictive properties.
How do animals demonstrate self-administration of addictive drugs?
Animals can self-inject drugs while pressing a lever
This behavior indicates the direct involvement of the brain reward system.
What is the consequence of short-term drug use on dopamine levels?
Short-term high but long-term dopamine depletion
This depletion drives compulsive drug-seeking behavior in addicts.
Which brain areas are key in addiction?
Ventral Tegmental Area (VTA) and Nucleus Accumbens
These areas are part of the brain’s reward or seeking system.
What is physical dependence in the context of drug addiction?
Physical dependence results from drug tolerance
Tolerance occurs when the body adapts to the drug, requiring more for the same effect.
What drives psychological dependence in addiction?
The Mesotelencephalic Dopamine System
This system plays a crucial role in the psychological aspects of addiction.
True or False: Addicts only seek drugs when external rewards are present.
False
Addicts continue seeking drugs even when no external rewards exist.
Fill in the blank: Addiction is a complex interplay of _______.
Neurochemistry, Environmental triggers, Cognitive & behavioral factors
These factors collectively influence the development and maintenance of addiction.
What happens when cocaine is infused directly into the nucleus accumbens?
Animals will learn to self-administer the drug
This shows cocaine’s direct effects on the brain’s reward system.
What is the primary reason addicts crave drugs despite negative effects?
Activation of dopamine release
This activation bypasses normal brain systems that assess the goodness or badness of an experience.
