Classical Conditioning

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Classical Conditioning Heroine Overdose

• Vanessa Bailey-Phillips
• PSY346

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Overview

• Review Classical Conditioning
• What is heroin?
• Heroin Mechanism of Action
• Risk Factors for Heroin Overdose
• Classical Conditioning Heroin Overdose
• Summary

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Classical Conditioning

• Definition
• A procedure that involves a neutral stimulus
  being paired with a stimulus that elicits a
  response until the neutral stimulus alone elicits
  a similar response
• Learning associations between stimuli

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Classical Conditioning

• PHASE I Before conditioning has occurred
• UCS
  UCR
• (meat powder)
  (salivation)
•  
• Neutral Stimulus Orienting Response
•  
• PHASE II The Process of conditioning
• Neutral Stimulus followed by UCS UCR
• (tone) (meat powder)
  (salivation)
•  
• PHASE III After conditioning has occurred
• CS CR
• (tone)
  (salivation)
•  

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What is Heroin?

• Derived from the poppy flower? Papver somniferum
• Heroin (diacetylmorphine), a semi-synthetic
  derivative of morphine, is produced by exposing
  morphine to acetic acid, inducing a chemical
  change to its structure
• Methods of administration
• - Orally
• - Inhaled
• - Subcutaneous injection (below the skin)
• - Injected directly into the veins (preferred
  because gets into the bloodstream and then
  blood-brain- barrier faster than any other
  method)

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Heroin Mechanism of Action

• Heroin is 3X more powerful than morphine, it
  deadens the sense of pain without losing
  consciousnesscausing intensely pleasurable
  reactions when first taken
• Heroin is a CNS depressant (agonist)
• Causes more of a euphoria experience than
  morphine
• Produces greater respiratory depression
• Greater antitussive activity (relives/suppresses
  
• coughing)

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Heroin Mechanism of Action

• Transforms into MAM (6-mono-acetylmorphine) by
  hydrosis and metabolizes into morphine once its
  reached the brain via the bloodstream
• Because of greater lipid (fat) solubility heroin
  easily penetrates blood-brain-barrier
• Heroin acts at the same receptors as the natural
  opiod system ? it is more effective than the
  endogenous transmitter they high jack the
  natural system by producing an exaggerated
  response
• Similar enough to endorphins, so it mimics its
  effects on an exaggerated level

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Heroin Mechanism of Action

• Studies have shown that the areas most sensitive
  to morphine, and therefore heroin are
• Hypothalamus
• Thalamus
• Amygdala

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Risk Factors of Heroin Overdose

• Demographics
• males represent 80 of OD fatalities
• mean agelate 20s to early 30s
• long-term dependent users
• rarely in drug treatment at time of OD
• Polydrug Use
• use of heroin with other drugs
• major drugs associated with heroin OD are
  alcohol, benzodiazepines and tricyclic
  antidepressants
• Heroin Purity
• Tolerance

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Tolerance

• Two factors relating the idea of tolerance with
  heroin overdose
• Tolerance is reduced after a prolonged period of
  non-use
• Tolerance reduced in non-drug-administration
  contexts (i.e. in a particular room)

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Tolerance Reduction

• Overdose fatalities appear to occur after periods
  of reduced use, for example
• After detoxification tolerance is reduced and the
  ex-user is more likely to die of an overdose
• Users who have been in prison and resume using
  after release
• Long term users may be at risk of overdose as a
  result of reduction in the difference between the
  dose required to achieve the desired effects and
  the does sufficient for lethal respiratory
  depression
• Tolerance to respiratory depression effects may
  have diminished more rapidly than their tolerance
  to the desired euphoric effects

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Tolerance Reduction

• Long-term experienced users among fatalities are
  expected to have a high tolerance, but in
  post-mortem autopsies it has been found that they
  have low blood-morphine concentrations
• Study Hair Morphine Concentrationslower than
  current users of heroin, indicating lower levels
  of heroin use in the period prior to death

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Tolerance Reduction

• Following a series of escalating drug
  administrations, each in the context of the same
  cues, tolerance develops to the potentially
  lethal effect of that drug as long as it is
  administered in the usual context
• Altering the context of drug administration
  increases the lethality of heroin

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Classical Conditioning Heroin Overdose

• Classical conditioning contributes to
  tolerancewhen heroin is administered repeatedly
  in the context of usual predrug cues (i.e.
  environment, atmosphere, etc), these cues elicit
  a conditional compensatory response (CCR) that
  weakens the effects of heroin

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Classical Conditioning Heroin Overdose

• As the drug is administered more often, and the
  CCR grows in strength, the weakening of the drug
  effect becomes more pronounced
• Explains overdose because the expression of drug
  tolerance is disrupted by presenting a novel
  external stimulus or by changing the context for
  each successive drug administration in an
  unpredictable manner
• Tolerance is more pronounced in the presence of
  the usual drug-associated cues than it is in the
  presence of alternative cues

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Classical Conditioning Heroin Overdose

• As heroin is administered with increasing
  frequency, with the same environmental cues
  signaling each pharmacological stimulation an
  association is established between these cues and
  the central effects of heroin (pain relief,
  euphoria, drowsiness, etc)
• Cues
• Exteroceptive? the physical environment (i.e. the
  room where the drug was adminsitered)
• Interoceptive? specialized sensory nerve receptor
  that responds to stimuli originating from within
  the body
• Pharmacological
• Self-administration

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Interoceptive Cues for Heroin

• Pharmacological
• Organisms can learn that a stimulus normally
  considered to be a UCS, signals the delivery of
  another UCSassociating two drug effects
• Basically a small does of a drug serves as a cue
  for a larger does of the same drug, intradrug
  associations
• Within each drug administration, drug-onset cues
  reliably precede the later, larger effect?
  potential for the formation of associations
  whenever a drug is adminsitered
• Drug-onset cues in common with exteroceptive
  cues, contribute to the tolerance of heroin

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Interoceptive Cues for Heroin

• Self-Administration Cues
• Self-administration cues acting as the CS
• Study showed that there was a difference between
  self-administration and the experimenter infusing
  the opiate intravenously
• Tolerance was observed when the subjects injected
  the opiate themselves, but not when the same dose
  was received by unsignaled intravenous infusion

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Classical Conditioning Heroin Overdose

• PHASE I Before conditioning has occurred
• UCS UCR
• (heroin)
  (pharmacological effects I.e.euphoria)
• Neutral Stimulus Orienting
  Response
• PHASE II The Process of conditioning
• Neutral Stimulus followed by UCS UCR
• (exteroceptive/interoceptive cues)
  (heroin) (pharmacology)
• PHASE III After conditioning has occurred
• CS CR
• (exteroceptive/interoceptive cues)
  (pharmacology)

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Summary

• A drug experienced individual can survive a dose
  many times greater than that which would kill the
  drug inexperienced individual
• Drug overdose in the drug experienced individual
  is a failure of tolerance
• Drug administration constitutes a conditioning
  trial
• CS environmental cues present at the time of
  administration
• UCS systemic effects of the drug

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Summary

• Anticipatory response attenuate drug effects and
  contribute to tolerance allowing the individual
  to continuously increase the drug dose
• Environmental signals of impeding pharmacological
  stimulation are important because it enables the
  individual to make compensatory conditioned
  response in an anticipation of the CS effects
• Failure to tolerance should occur if the drug is
  administered in an environment that has not been
  associated with the drug previously

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The End