Lecture Notes for Dr. Troisi's Guest Lecture


Learning Theory and Drug Abuse

History of drug use by humans

Ancient to modern desire to modify consciousness

Discovery of brewing to make beer - modern synthetic opiates

Why study substance abuse

Substance abuse costs $500 billion/year in the US

Legal, health care, ID theft, Education outreach, lost time at work, NIDA budget, etc.

85% - related to alcohol and cigarette use

Operant conditioning model and its usefulness to studying drugs

Model: behaviors have consequences

Perform certain behavior - receive reward

Examples: dogs and food, rats bar pressing for food, primates and humans

Physiological basis - neuroreward system in the brain

Interactions among pre-frontal cortex, nucleus accumbens (NA), VTG area, Limbic System

Important findings

Animals and human abuse many of the same drugs except hallucinogens (Humans only)

Studying humans and addiction

Tool - drug abuse liability assessment of drugs by experienced users

Involves asking addicts/user to evaluate drugs for their abuse liability

Scales, questionnaires - request feedback on how potent/good the drug makes the user feel

What would they pay for a drug

Compare the cognitive abilities of users under the influence

Results used to assess the probability that a drug would be abused

History of cue reactivity

Role of Pavlovian conditioning and Pavlov's Dog

Food causes dog to salivate

Metronome paired with food eventually causes dog to salivate

Addicts crave drugs after they learn to associate cues with taking drugs and euphoria (high)

Interoceptive cues - from within the body (emotional responses: anger, stress, celebration, other)

Exteroceptive cues - outside the body (crack house, bar room, other

Siegel experiment - experimental evidence of cue reactivity

Training Experiments

Rats given morphine in Context A - euphoria

Rats given saline in Context B - nothing

After Training Experiments

Rats given saline in Context A - withdrawal

Rats given morphine in Context B - overdose

Drug discrimination experiments: collaboration between Troisi lab and University of Kentucky

Quail experiments

Male given cocaine, followed by presentation of receptive female and sex/copulation

Male given saline, followed by no presentation of receptive female

Males learn to discriminate between message from cocaine versus saline

Also performed reciprocal experiment (cocaine - no female, saline with female)

Therapy - classical versus operant conditioning

Classical conditioning model - use extinction

Lab setting: addict exposed to cues up until self-administration, then stop

Goal: extinguish learned association between cues and euphoria

Problems

Relapse, spontaneous recovery after addicts leave the lab setting

Drug seeking behavior and assoications are more complicated chain of events

Operant conditioning and the Operant chain

Drug seeking involves many more events that are learned and predict euphoria

Seeking dealers, Obtaining $$, Using paraphernalia, etc.

More complicated than just classical conditioning and extinction

 

 

 

 




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Copyright © 2001 Jay Pitocchelli. All rights reserved. The contents of this page are the intellectual property of Dr. Jay Pitocchelli for distribution to students enrolled in General Biology BI 01 at Saint Anselm College. These pages may not be copied, photocopied, reproduced, translated, or published in any electronic or machine-readable form in whole or in part without prior written approval of Jay Pitocchelli. Students enrolled in General Biology BI 01 at Saint Anselm College have permission to print this material for their lecture notes. The images linked to this web page are the sole property of Addison Wesley Longman Publishers™.