Lesson 6 (ch 3): expectation, sensitization, and tolerance

sensitization

• non associative learning

• increase in responding as a result of experience

habituation

• non associative learning

• behavior that decreases it frequency associated with non associative learning (going through an experience)

Mithridates VI

• king in ancient turkey

• paranoid he was going to be poisoned, so throughout his life he exposed himself to tiny doses of poison, so if someone tried to poison him it would not work

  • tolerance

tolerance

• seen as either

  • decrease in drug effect with repeated administration of the same dose

  • increase in dose required to produce an effect as intense as one produced by earlier doses

Acute tolerance

• happens fast, or in an initial dose of the drug

  • drug effect can be greater at different blood levels during absorption than elimination

  • as we absorb a drug, it gives us some effect → then our body starts to kick in all the extra processes to try and account for it and return to homeostasis → tapers off the drug effect faster than we would expect based on how much is in our blood

Pharmacokinetic tolerance

• increase in the rate or ability of a body to metabolize a drug

  • fewer drug molecules reach site of action → expect some level of drug to always be in the body

Pharmacodynamic tolerance

• the actions of the drugs on the nervous systems → effects of drug are reduced by physiological changes that our bodies make to compensate for the drug

upregulation

• if drug blocks receptor sites, neurons will increase the number of receptor sites

downregulation

• if drug stimulates receptor sites, neurons will reduce receptor affinity or the number of receptors

functional disturbance tolerance

• has a noticeable disruption on homeostasis that has some consequence on us as a human

  • ex → alcohol reduces core body temp; to tolerate, roll our strategies to warm up

behavioral tolerance

• based on drug discrimination learning; organisms sometimes learn after many exposures to function reasonably well under doses of a drug that may be debilitating to those who have never used it

Sensitization (reverse tolerance)

• less common

• increase in a drug effect after repeated administration

  • amphetamines, cocaine, and opioid drugs

• shown in 2 ways:

  • repeated administration in a specific environment shows sensitization that disappears or dissipates when given in a different environment

  • environment will act as a conditioned stimulus for a drug like response

cross sensitization

• sensitization across multiple different drugs → show sensitized effect from one drug when using another

Withdrawal

• grouping of symptoms that come on when you stop taking the drug, or you decrease the amount you are taking (physiological changes)

• can be mild or violent/life threatening

• only way to get rid of symptoms is to reintroduce the drug

• whatever the effect of the drug is, these symptoms tend to go in the other direction

  • ex → CNS depressants produces symptoms characterized by CNS hyper excitability

physical dependence

• to be dependent on a drug

  • state of being where the body has learned to expect some amount of drug presence, such that when you remove it withdrawal symptoms occur (not addiction)

cross dependence

• whenever drug A stops withdrawal symptoms caused by drug B

opponent process theory

• A (alpha) process followed by later B (beta) process

  • B process cancels out A process

  • B process lasts longer, so when A ends, B dominates (withdrawal)

    • in an unpleasant state longer than pleasurable)

• with repeated use → B process intensifies, begins sooner, and lasts longer

A process

• initial pleasurable state → initiated by taking the drug

B process

• compensatory unpleasant state → body realizes some drug has been introduced

hangover

• compensatory response after a single drug administration

what is being conditioned with drugs (classical conditioning)

• compensatory process

  • usually the B process

• most of the time the effect will be the opposite of the drug effect

2 effects of morphene

• A process → analgesia (pain killer)

• B process → hyperalgesia (sensitivity to pain)

placebo effect

• pain relieving drugs work better, but both have measurable reductions in pain

• sometimes you have to see the injection happening in order for pain relief to actually happen

novel environment

• drugs have a greater activating effect

• drug sensitization is faster and stronger