Drug Tolerance and Addiction Flashcards

Flashcards about drug tolerance, homeostasis, and addiction.

What happens to the dose-response curve when tolerance to a drug develops?

The curve shifts to the right, meaning a higher dose is needed for the same effect.

What is homeostasis?

The tendency of living organisms to maintain certain parameters within acceptable limits.

How does the body respond to a drug that disrupts homeostasis?

Through negative feedback mechanisms that counter the effects of the drug.

What are some ways the body can develop tolerance to a drug over time?

Better elimination of the drug, changes in the number or sensitivity of receptors, or changes in intracellular processes.

What is a withdrawal effect?

The body's tolerance mechanisms pushing in the opposite direction once the drug is removed, leading to the opposite effects of what the drug was doing.

What is physical dependence on a drug?

Experiencing withdrawal symptoms when the drug is not taken.

How does context relate to drug tolerance?

Tolerance can be classically conditioned to the context in which the drug is taken, triggering compensatory responses in that environment.

Why can overdosing occur in novel environments?

Because the context does not trigger the tolerance response, leading to a stronger effect from the same dose.

What is operant conditioning?

A stimulus triggers a behavior that leads to a reward, making the behavior more likely to be repeated.

What brain areas are key for reward and reinforcement?

The nucleus accumbens and the ventral tegmental area (VTA).

What is the mesotelencephalic dopamine system?

A system that connects the midbrain to the endbrain, using dopamine as its neurotransmitter.

Which neurotransmitter is released from VTA to nucleus accumbens during reward?

Dopamine.

What effect does blocking dopamine receptors in the nucleus accumbens have on self-stimulation?

It prevents animals from learning to press the lever for stimulation.

What is the seeking hypothesis (related to dopamine)?

Dopamine release has less to do with pleasure and more to do with driving animals to gather information and repeat behaviors.

What is psychological dependence?

Activation of the ventral tegmental area and nucleus accumbens connection involved in the rewarding or seeking system.

How do addictive drugs bypass the normal reward system?

They directly activate dopamine release in the nucleus accumbens, leading to a compulsion to take the drug again.

What is the medial forebrain bundle?

Bundle of axons running from the midbrain to forebrain with dopamine as a neurotransmitter

What is addiction?

In these lecture notes, addiction is defined as behavior caused by physical (withdrawal) and/or psychological (dopamine release) dependence.