Chapter 3: Part 3 - Conditioned Drug Effects, Sensitization, and Expectancy.

What is behavioural tolerance?

The ability to learn through experience to reduce the effects of a drug.

What two types of conditioning contribute to behavioural tolerance?

Classical conditioning and operant conditioning

What is classical conditioning?

Learning through repeated associations between stimuli.

What types of responses are involved in classical conditioning?

Involuntary or reflexive responses, such as physiological and emotional responses.

What is an unconditioned stimulus (US)?

A stimulus that naturally produced a responce without learning.

What is an unconditioned response (UR)?

An automatic unlearned response to an unconditioned stimulus.

What is a conditioned stimulus (CS)?

A previously neutral stimulus that produces a learned response after repeated pairings.

What is a conditioned response (CR)?

A learned response triggered by a conditioned stimulus.

What are compensatory responses to drugs?

Physiological responses that act opposite to the drug’s effect

How does classical conditioning contribute to drug tolerance?

Environmental cues associated with drug use trigger compensatory responses that reduce the drug's effects.

What is conditioned drug tolerance?

When environmental cues associated with drug use trigger compensatory responses that reduce the drug's effects.

Why can taking a drug in an unfamiliar environment increase overdose risk?

The usual environmental cues are missing, so conditioned compensatory responses may not occur, reducing tolerance.

What was the purpose of the heroin tolerance experiment with rats?

To determine whether environmental cues influence drug tolerance and overdose risk.

Which group of the rats had the lowest mortality in the heroin experiment?

The same-environment group, because familiar environmental cues triggered conditioned tolerance.

Why couldn't pharmacokinetic or pharmacodynamic tolerance explain the mortality difference?

Both heroin-exposed groups had the same drug exposure, but different mortality rates due to learned tolerance.

What is operant conditioning?

Learning through reinforcement and punishment, where behaviours become associated with their consequences.

What is Differential Reinforcement of Low Rates (DRL)?

A reinforcement schedule where an animal is rewarded only if it waits a certain amount of time between responses.

What was the purpose of the Campbell and Seiden (1973) experiment?

To investigate whether rats could develop behavioural tolerance to amphetamine through learning.

What happened to rats that received amphetamine before training over 28 days?

They learned to control their responses and earned as many food rewards as the other group, demonstrating behavioural tolerance.

How did researchers confirm that the amphetamine experiment demonstrated behavioural tolerance?

When Group 2 received amphetamine before training, they could not control their responding despite having previous drug exposure.

What was the main conclusion of the Campbell and Seiden (1973) experiment?

Behavioural tolerance depends on learning and experience while under the influence of a drug, not just repeated drug use.

What is drug sensitization?

A progressive increase in the behavioural or physiological response to a drug after repeated, intermittent exposure.

What is another name for sensitization?

Reverse Tolerance

What is the main difference between tolerance and sensitization?

Tolerance: The response to a drug decreases with repeated exposure.

Sensitization: The response to a drug increases with repeated exposure.

What types of drugs commonly demonstrate sensitization?

Stimulants that increase activity in the brain's dopamine reward system, such as cocaine.

What happens in the brain during drug sensitization?

Repeated exposure causes long-lasting increases in dopamine system responsiveness and neural plasticity in reward pathways.

What brain pathway is particularly involved in sensitization?

The mesolimbic dopamine pathway.

What three brain areas undergo long-term changes during sensitization?

Ventral tegmental area (VTA)

Nucleus accumbens (NA)

Prefrontal cortex (PFC)

How can learning and environmental cues influence sensitization?

Cues associated with drug use can activate reward circuits, making responses stronger and faster.

How can expectations influence the effects of a drug?

Positive or negative expectations can strengthen or weaken a drug's perceived effects and treatment outcomes.

What was the purpose of the Bingel et al. (2011) experiment?

To investigate how expectations influence pain relief from the opioid drug remifentanil.

What were the four conditions in the Bingel experiment?

1. Baseline (saline)

2. No expectation (drug given without the person's knowledge)

3. Positive expectation (told the drug was being given)

   1. Negative expectation (told the drug was being discontinued)

What happened when participants had positive expectations about pain relief?

They experienced greater pain relief compared to when they did not know they were receiving the drug.

What is the placebo effect?

A beneficial change in symptoms or physiological state caused by positive expectations about a treatment, even without a specific active treatment effect.

What is the nocebo effect?

A negative change in symptoms or physiological state caused by expecting harmful or unpleasant effects.

What is the main difference between the placebo and nocebo effects?

Placebo: Positive expectations can produce beneficial effects.

Nocebo: Negative expectations can produce unpleasant or harmful effects.

How did researchers confirm the influence of expectations on pain perception?

MRI brain scans showed that pain-related brain activity changed according to participants' expectations and matched their reported pain levels.

What is the overall relationship between expectations, context, and drug effects?

Expectations and environmental context can change how strongly a person experiences a drug's effects through learned and brain-based responses.