End of Ch3 Flashcards
Sensitization
The reverse of tolerance. An increase in drug effect with repeated administration.
Ex: an increase in motor activation effect of amphetamine with repeated low doses (diagram of response curve)
Sensitization is shown in two ways…
1) Repeated administration in a specific environment shows sensitization that disappears/dissipates when given in a different environment
2) Envrionment will act as a CS for a drug-like response (ex: high rate of motor activity in absence of amphetamine)
These are mirror images of conditioned tolerance
How is sensitization unlike tolerance? How long do each last?
Sensitization is more persistent than tolerance. Sensitization can last 1 year after drug exposure; increases with time
Expectancy: the placebo effect is responsible for what percentage of the effects of antidepressants and analgesics
70% of the effects of antidepressants, 50% of effects of analgesics
Expectation mechanism
top-down path from cortex to pain relief centre activated by expectation of a pain relief effect. It is responsible for the placebo effect of analgesic drugs.
What areas does expectancy activate and why?
orbito-frontal cortex, dorsolateral prefrontal cortex and anterior cingulate, insular cortex, periaqueductal gray all activate in anticipation of painful stimulation
What is expectancy involved in?
Cognitive control, anxious anticipation, motivation, and affective response to expectation of pain (the placebo effect can decrease activity in some of these areas)
Placebo response can be blocked by ____, but only if_____. Place analgesia is mediated by more than one system, not just ____
Placebo response can be blocked by naloxone, but only if there’s no past history of experience with analgesics. Placebo analgesia is mediated by more than one system, not just endogenous oplates
Nocebo effect
side effects generated by placebo; expectation of harmful effects, specific to the drug the person believes they are taking
