Chapter 2 - Conditioning with Drugs as O's

Question 1

What is a conditioned compensatory response?

Answer 1

it functions to return the body to equilibrium by producing the opposite physiological response in preparation of the drug to cancel the drug’s effects on the body
i.e. if the drug has a direct effect of increasing BP then the body produces a compensatory response by decreasing BP prior to taking the drug so that when the drug is taken and BP raises, it won’t be Fatal or lead to overdose

Question 2

What is drug tolerance?

Answer 2

drug tolerance is the habituation that occurs after repeated exposures to a drug

Question 3

What did Shepard Siegel propose about drug tolerance?

Answer 3

He said that tolerance resulted from classical conditioning and that each time a drug is taken (R ==> the behaviour), its effects (O ==> biological outcome) are associated with environmental cues (Stimulus)

The body might then come up with a compensatory response in the presence of those environmental cues

Question 4

What is the drug effect equation?

Answer 4

Drug effect = Direct effect - Conditioned Compensatory response

the CCR gets stronger with each drug exposure and eventually pretty much cancels out the direct effect of the drug

Question 5

Describe experiment of morphine administration on rats in the presence of different environmental cues (CS)

Answer 5

• had two groups of rats; one group was in room A and the other was in room B
• both groups were given morphine in each room at the same amount and both groups developed tolerance from it
• then the rat group in room B were moved to room A, and given the dose of morphine same as the rats who were in room A and the experimenters tested the pain sensitivity of both groups of rats after being given same amount of morphine by seeing how long it took for them to take their hands off a hot plate (the longer it took to remove hand, the less sensitive to pain and the less tolerance from morphine; the short removal of hand from hot plate indicates tolerance to morphine as the body is producing a conditioned compensatory response by increasing pain sensitivity prior to morphine being taken)
• results show that rats that were initially in room B kept their hands on hot plate longer because the environmental cues that were present in room B that caused the body to expect morphine and increase pain sensitivity were absent, therefore the direct effect of morphine was higher for them. The rats in room A had more sensitivity to pain because they were more familiar with the environmental cues of room A and developed CCR and tolerance.

Question 6

Describe the experiment of where the morphine conditioned compensatory response (CCR) was tested directly in rats?

Answer 6

in this experiment, the researchers wanted to see if body responses of rats were driving their sensitivity to pain

• same kind of experiment: where rats were conditioned to develop tolerance to morphine in two different rooms: room A and room B
• rats from room B moved over to room A
• WITHOUT administering another dose of morphine, the researchers immediately tested pain tolerance of both rat groups by placing their paws on hot plates and seeing how long it takes for them to remove their paws
• results showed that even without morphine being administered at all, the rats in room A had a predisposed high pain sensitivity as a result of CCR & environmental cues; however, rats in room B who went to room A were never predisposed to the environment of room A therefore never developed a CCR and their pain sensitivity was therefore lower than that of room A because room A had already been conditioned to have.a CCR of increase pain sensitivity

so Rats trained in room B did NOT expect morphine in room A and therefore had lower pain sensitivity and moved their paw in 9.1s

while rats trained in room A expected morphine in room A, and developed a CCR of increased pain sensitivity and lifted their paw in 4.4 sections

Rats that expected morphine (due to CS-US pairings) were more sensitive to pain

Question 7

Describe the experiment where rats were injected with heroin and saline in a new context?

Answer 7

this is an experiment to highlight the adaptive features of drug tolerance and how it protects against overdoses

• had two groups of rats; one in room A and one in room B and a control group
• they injected rats in room A and room B with heroin and control group rats with saline
• At the end, they gathered all the rats in room A and administered the same dose of heroin to all of them
• results showed:
  96% of control rats died
  32% of room A rats died
  64% of room B rats died

this demonstrates that individuals naive to the drug are at the greatest risk of overdose initially, and individuals who were from a different environment, exposed to the same dose in new environment had a greater chance of overdose due to lack of tolerance; and individuals who were protected the most from the dose were the ones that developed tolerance and CCR due to the environmental cues