Notes on the Web
Neurophysiology of Addiction

• Unit Four - Part 6 (of General Zoology and General Biology Class Materials)
• Nervous System Unit (for Human Anatomy and Physiology II)

Bruce G. Stewart

Your general objectives for this chapter are:

• To describe the neurophysiological affect of mood changing, mind-altering drugs on the reward system of the brain;

• To describe the chemical and cellular basis for the affects of mood-changing, mind-altering drugs, especially methamphetimine, cocaine, heroin, and alcohol,  in the reward system of the brain;

• To identify healthy brain versus drug-damaged brain PET scans;

• To describe the role of positive reinforcement in the formation of healthy motivational hierarchies in humans;

• To describe an affect and mechanism that causes drug use to produce motivational toxicity;

• To understand and describe the disease concept of addiction including the medical reasons for this classification;

• To be able to list at least five components that contribute to treatment strategies for the disease of addiction.

Related Textbook Readings:

• For Human Anatomy and Physiology II (AP 2134) Class only: You will have already covered the necessary nervous system physiology basics, so no additional textbook material is required
• For General Biology (BIO 1114) Class only:  Johnson and Losos (2008) - Readings to be assigned in class.
• For General Zoology (ZOO 1114) Class only:  Hickman, et al. (2004) Chapter 4 (confirm details in class)

Neurophysiology of Addiction and Related Addiction Materials

The material on this topic will be covered in class in one or two hours of lecture (or for Internet biology during one of the two lab days plus threaded discussion via Internet).  You should review my PowerPoint presentation that outlines and illustrates this lecture. I give this presentation each semester at Murray State College and at public lectures related to the issue. However, for our various life science classes, the emphasis will be more on the biological aspects of the material. For those who have not seen the PowerPoint presentation in person, here is a link. However, please note that this is a 9mbyte file and should be downloaded only if you have a very fast connection.

DRUG AWARENESS SEMINAR/LECTURE, 7th ED.

There is also an important research paper to study.   This is a research review article by Dr. Michael Bozarth called Pleasure Systems of the Brain.  You do not have to read the entire article, but I will review selected portions of it in class, on a lab day, and/or via threaded discussion on Internet..  Some (but not all!) terms to know included:

• positive reinforcement
• mesolimbic (=ventral tegmental) dopamine system
• motivational hierarchy
• motivational toxicity
• addiction continuum
• addiction

Related Links

The following are useful links for your reference, but there are no additional materials for testing from these sources. Some additional resource links are given in the PowerPoint lecture previously referenced.

• This link is from the Addiction Science Network:  Primer on Drug Addiction.  This presents a nice overview of the disease of addition.
• Another ASN page is called The Biological Basis of Addiction.  This site gets down to the specific ways that heroin and cocaine affect dopamine neurons in the mesolimbic dopamine system of the brain.  Also, here is a link to a graphic that shows the location of the mesolimbic dopamine system and the effects of chronic drug abuse on dopamine neurons:  Society for Neuroscience - July 1997 Brain Briefings 
• National Institute on Drug Abuse Research Report Series has many resources.  This one is on Methamphetamine: Abuse and Addiction.
• We do not have time in lecture to do justice to the topic of the disease of addiction or the neurophysiological effects of more than the above brief examples.  Alcohol, marijuana, inhalants, ecstasy, and countless other substances are abused and each has its own negative, destructive effects on normal function of the human brain.  I strongly recommend that you take some time to explore the National Institute on Drug Abuse web site for more information.  Be careful on the web!  You must determine the credibility of the individual or organization that sponsors a site.  Then you must also understand that only a fraction of websites have any kind of peer review associated with the materials published there.  Look for websites sponsored by reputable research and/or education organizations that should have at least some reliability.  Avoid websites independently set up by individuals who might have who knows what kind of expertise and biases (or lack thereof).

Here are some specific links from NIDA and the National Institute on Health (NIH):

• Marijuana:
  • http://www.nida.nih.gov/Infofax/marijuana.html
• Cocaine:
  • http://www.nida.nih.gov/ResearchReports/Cocaine/cocaine3.html#effects
• Alcohol: 
  • http://silk.nih.gov/silk/niaaa1/questions/asked.htm
  • http://silk.nih.gov/silk/niaaa1/publication/arh21-2/108.

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