Lecture 1 Class Intro UW Bio Lesson 1 Introx

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Transcript Lecture 1 Class Intro UW Bio Lesson 1 Introx

UW Bio 100
Unit I: Intro to Neurobiology
Lecture 1
Each state in the US is spending a very
large amount of taxpayer money to deal
with the social, legal, and medical
impacts of drug abuse.
A survey of expenditure in Washington
State found that about $32 billion dollars
went into issues related to drug use.
Most of that money
was spent on the
impact to communities
after people used drugs
• medical &
impacts to users
• social issues to those
affected by the users
• refer to D in the
graph below
Compared to this, very little
money is spent on treatment
(B), or better yet, prevention
(C) in the graph shows the costs
relating to formulating and
enforcing drug policy.
Image statistics come from: http://www.dshs.wa.gov/pdf/HRSA/DASA/2009%20Trends%20Report.pdf
A word from Doc Linda
In this class, you will have the opportunity to deeply
investigate a number of mood altering drugs, from
nicotine to LSD.
For each drug, you’ll become well acquainted in the
biological reasons these drugs influence mood, from
the level of molecules to the understanding of brain
anatomy and function.
Throughout, you’ll focus on the reasons why some of
these mood altering drugs are addictive. Addiction is a
serious mental and medical condition that befalls many
people who have no intention of leading a life
consumed by drugs.
A word from Doc Linda cont.
To introduce our topic to you, we’ll touch on a few
different biological principles. To fully understand any
mood altering drug, it will help to have a basic
understanding of molecules in general
◦ specifically the molecules that influence how brain cells
It will also help to understand how drugs are
processed by the body.
 And because you will learn why some people are
more (or less) prone to addiction in general and to be
impacted by a specific drug, coverage of how these
individual differences are determined and
transmitted will be important.
A word from Doc Linda cont.
So for this class, you will be asked to understand:
◦ Neurobiology (Unit 1),
◦ Pharmacology (Unit 2),
◦ and Genetics (Unit 3) before launching into the analysis of each
Mood Altering Drugs & Adolescents
Video Guiding Questions
In your journal:
◦ What are the qualifications of the person who is
answering these teens’ questions?
◦ What experiences do these teens describe that indicate
drug use affects them?
◦ What does this video suggest about ways scientists can
measure how a drug impacts the brain?
◦ Why do some drugs make us feel pleasure and why do we
have a pleasure center in the brain in the first place?
◦ Be able to name four psychoactive drugs discussed by this
Activity 1:Mood Altering Drugs
and Adolescents
Dr. Nora Volkow’s visit to Harlem’s School of Math, Science and
Engineering at City College.
As you watch the video, you will learn a little bit about how to use this
course and your instructors to find answers to your questions about drug
Altering Drugs and Adolescents
Then view this video, "Facts About Drug
Addiction" about what addiction is:
Guiding Questions (in journal)
◦ How does one neuron communicate to another?
◦ What is the definition of a "drug"?
◦ Explain why some drugs are addictive. Consider the
pleasure the drug gives, and the terms dependence
and withdrawal.
Unit I Activity 2
Addiction Popularized
 Consider any drug users you may know (this
includes alcoholics).
 Where did it begin for them?
 Why do you think that they continue to use?
 Do you think they are uninformed or
 Now think of a song that depicts an addict or
Why Do Drugs Affect Our Mind?
We experiment with all sorts of things that influence how we feel.
Historically, humans have found substances to
consume that influence our minds & bodies.
Early peoples experimented with newly
discovered plants and thereby found them to
be either nutritious or medicinal.
Some were found to alter perspective and
◦ Why?
◦ What substances?
Why Do Drugs Affect Our Mind?
Let’s take nicotine as
an example: Why does
nicotine effect how we
◦ Nicotine (and other
mood-altering drugs)
has the ability to
influence the chemistry
of our brains.
The molecules within the
plant can bind to
molecules in our brains
 This results in altered
brain function at a cellular
Why Do Drugs Affect Our Mind?
Basic Chemistry Review:
 What are molecules composed of?
 Atoms of one or more element
How are the components held together within a
 Covalent (shared) bonds or Ionic (transferred)
How do molecules vary in size from water to
polymeric molecules, such as DNA?
◦ http://scaleofuniverse.com/
Why Do Drugs Affect Our Mind?:
When molecules enter our body, those that are large (like
proteins or fats) need to be broken down or metabolized
to be used.
Read the Olestra article
Guiding Questions (in journal)
◦ How do triglycerides compare to Olestra in structure?
◦ How do triglycerides compare to Olestra in terms of
digestibility? Why?
EW 9/11
How does the structure of Olestra
compare with triglycerides?
 Would you expect a drug like cocaine to
be more similar to Olestra or a
triglyceride in terms of how your body
might process it?
Why Do Drugs Affect Our Mind?:
The story of drug molecules is the
opposite of the Olestra story.
◦ Rather than find a molecule our body cannot
use, with most drugs, our bodies do recognize
them and do respond to these molecules.
Why Do Drugs Affect Our Mind?:
Role of Ligands
 Drugs are recognized by the body depending on
how closely they resemble the normal ligand.
◦ A ligand is a molecule that binds to another;
frequently, a ligand binds to a receptor.
If a drug very closely resembles the ligand  the
binding will result in an impact that is close to
that of the ligand.
If the drug can bind, but is very different in how it
binds the result will not precisely match the
result of the normal ligand-receptor binding.
Why Do Drugs Affect Our Mind?
Ligands cont.
Back to our ancestors…
◦ Imagine that the drug molecules they might have taken
into their bodies for the first time.
◦ The three shapes below represent molecules that have
some of the chemical properties necessary for them to
be able to bind to the receptor (shown in blue).
Why Do Drugs Affect Our Mind?
Ligands cont.
◦ When nothing is bound to the receptor (very left), the
receptor remains "inert".
◦ Another brain molecule may bind to this receptor as part of
the course of normal activity and the binding between this
ligand and receptor usually results in some change to the cell.
But each drug molecule will effect the receptor differently.
Why Do Drugs Affect Our Mind?
Ligands cont.
“Normal" ligand (dark red)a brain molecule we make ourselves that
binds to the receptor in order to accomplish some outcome.
◦ When "normal ligand" binds to receptor, the receptor responds by changing
its shape.
◦ This shape change results in changes to the cell red dots can now enter
Why Do Drugs Affect Our Mind?
Ligands cont.
Some drug molecules resemble the "normal" ligand
very closely very close in shape and chemistry to
the ligand.
 The effect this type of drug (orange shape in center)
has on the receptor is virtually identical to the effect
the ligand has.
◦ This type of drug is termed an agonist for this receptor.
Why Do Drugs Affect Our Mind?
Ligands cont.
The drug molecule represented by the yellow shape
can bind to the receptor, but when it binds, there is
no effect on the receptor.
 The effect on the body is that the receptor site is
bound, and no longer available for the ligand to
 This type of molecule opposes the effect of the
"normal ligand". It is an antagonist for this receptor.
Why Do Drugs Affect Our Mind?
Ligands cont.
It is possible for a drug to act as a partial agonist.
In this case, some, but not all of the effects a "normal
ligand" has on the receptor are seen.
Neurons & Neurotransmitters
Test of Content
Cocaine binds to and blocks dopamine recycling
receptors. Dopamine is a brain chemical that
stimulates neurons. When cocaine is bound,
dopamine can no longer be recycled into a neuron.
◦ What type of binding does cocaine show?
LSD binds to serotonin receptors and when it does,
some of the changes that occur when serotonin
binds are seen, others are not. Serotonin is a brain
chemical much like dopamine.
◦ What type of binding does LSD show?
Essential Readings: Required
Liska, Ken. Drugs and the Human Body: With Implications for
Society, 8th edition. Upper Saddle River, N.J.: Prentice Hall, 2008.
The Magic Bullets - Chapter 1
What is a Drug
Drug Dependence
Receptor-Site Theory
NIDA InfoFacts: Understanding Drug Abuse and Addiction
How Stuff Works: Atoms and Molecules
Wikipedia: Agonist-Antagonist
Supplemental Reading
Liska, Drugs and the Human Body
Where Drugs Come From
MayoClinic.com: Drug Addiction
How Stuff Works: How Addiction Works
Drugs from Plants
Examples of Plant-Source Drugs in Use Today
Plant Sources of Illicit Drugs
The Future of Drug Discovery
Introduction to How Addiction Works
Addiction as a “Brain Disease”
Addiction Symptoms
NIDA: Drug Abuse and Addiction: One of America's Most Challenging Public Health
Faces of addiction
Trends in drug abuse
Addiction is a chronic disease