Getting to Know Your Nervous System
Do Drugs Really Make You Happy?
Hello, my name is Dr. Linda Gorman and I am a neuroscientist at Johns Hopkins University.
Question: Does anyone know or can anyone guess what a neuroscientist studies????
Your brain….which is part of your nervous system.
Today I am here to talk to you about your nervous systems’ and how drugs work.
My feeling is that if people really understand what drugs do to their brains that they can make a
more informed decision as to whether or not to use them.
So I am going to talk to you about your brains and drugs.
This is a picture of what your body would look like without your skin, muscles, bones, or other organs.
This is your nervous system.
Your brain is part of your nervous system. But your brain is connected to your spinal cord in your
back and all these nerves.
Your brain is connected to every single part of your body.
That is because every part of your body ―talks‖ to your brain and your brain ―talks‖ right back to every
part of your body.
Question: What do you think that your eyes ―tell‖ your brain? Your ears? Your muscles? Your nose?
Question: What do you think that your brain tells your body?
(Kids will probably answer with mostly movements)
Your brain also tells your body to do things that you don’t even know about…..like it tells your
heart to beat, it tells your lungs to breath, when you are cold it makes you shiver to warm you up,
This is a picture of a REAL brain and spinal cord.
?DO DRUGS MAKE YOU HAPPY?
Now, do drugs make you happy?
Yes. I won’t lie to you. Drugs do make you happy. Of course they do. That is why most people
want to take them.
Most of the drugs that people take all do one basic thing…..they relieve stress.
They interact with our nervous systems and help to relieve stress.
Question: Does anyone know what stress is?
Everyone has stress in their lives.
Drugs help to relieve that stress…..or do they????
In your brain, there is a place that is called the reward center.
Question: What is a reward?
It is usually something good that you get when you do something good.
We know that every single one of the drugs that people take to ―relieve stress‖ work by interacting
with a system in your brain, known as the reward center.
We found out about this reward center by doing studies in animals – rats mostly.
We have known about the reward center of the brain for a long time.
In 1954, James Olds and Peter Milner were the first to demonstrate that intracranial electrical
stimulation could be used in operant conditioning experiments to replace a primary reinforcer.
Whenever your reward center is active you feel happy.
Activation of this center –basically makes you experience pleasure….happiness.
So we actually have a place in our brains that is organized to make us happy.
Happiness must be pretty important.
Most of the natural things that make us ―happy‖ – that activate our reward center - are tied to our
survival. (Survival is pretty important.)
They are termed primary reinforcers.
These are things like food, water, sleep and sex. Primary reinforcers are also things like
maintaining body temperature – keeping warm and cool - tied to shelter – and nurturing behaviors
– so our offspring survive to pass on our DNA.
We need this reward system for our survival – not only as an organism, but as a species.
The reward system motivates us to do what is good for the continuation of the species.
We have to seek nourishment, shelter, food, water and we have to procreate. All of these things
are associated with pleasure. This is probably because we want to make sure that the organism
seeks out things that it needs to survive and procreate.
DRUG & REWARD CENTER
Drugs activate our reward system, to make us happy.
DRUG & REWARD CENTER
Drugs make our brains happy than the normal things that make us VERY happy.
This is because drugs activate our reward center faster and longer than the natural things that
activate the reward center.
DRUG & REWARD CENTER
Drugs make us very happy.
But, they only make our brains happy when we are taking the drugs.
Then, something happens and even though we are taking the drugs – the drugs aren’t making us as
So, we have keep taking more and more of them.
But, the more we take, the more our brains want.
?WHAT IS HAPPENING?
To understand what is happening, we need to know more about how our brain works.
Question: Has anyone ever made a puzzle?
You put little pieces together.
Your brain in made up of little pieces, called cells.
Neurons are the cells that make up your brain.
Neurons are all connected together in your brain. Neurons send messages to each other and to
other parts of your body.
Neurons ―talk‖ to each other by spitting out chemicals.
These chemicals are called neurotransmitters.
The neurotransmitters are made in the cell and then they travel down a long tube, known as an axon.
When we talk about nerves, we are talking about those long tubes that carry the
neurotransmitters – the axon.
Axons are nerves!!!!
Neurons send chemical messages to each other.
Here you see one neuron ―spitting out‖ a chemical and another neuron ―catches it‖.
Sometimes are brains are not working quite right and we need to take drugs to make it feel better.
Good drugs help your brain chemicals work better.
BUT….there are some drugs out there that hurt your brain.
Some of these drugs have fun, cute names, but they actually hurt your brain.
?DRUGS AND PRIMARY RIFS
By taking drugs, you change your brain.
Now things that your body needs, that would normally make you happy, don’t make you happy
?DRUGS AND HAPPINESS
Now, the only thing that makes you happy are the ―bad‖ drugs.
But, the bad drugs stop your brain chemicals from working to send their messages.
?DRUGS AND NORMAL NEUROTRANSMISSION
The ―bad‖ drugs block the normal chemicals in your brain from working.
So, you used to have a normal happy brain.
But, because you started taking bad drugs the drugs changed your brain.
You now have a brain disease.
You have flipped some kind of switch in your brain and you now have an addicted brain.
When does this switch get flipped?
We don’t know. We know that some people can take drugs once and become addicted.
Some people can take drugs lots of times before they become addicted. We just don’t know.
But, all drugs that make you happy change your brain – and eventually will flip your switch and turn
your normal healthy brain into a diseased brain.
Lots of drugs can give your brain a disease.
Plus, we know that some drugs flip the switch faster than others.
Heroin and cocaine are the most addicting drugs.
Nicotine and alcohol are more addicting than marijuana.
?ADDICTION AND STRESS
Your addicted brain works differently.
Addiction is like constant stress.
?DRUGS AND STRESS
How does taking drugs cause your brain stress?
?REGULATION OF PRIMARY REINFORCERS
All of the natural things that activate the reward system are very heavily regulated.
Natural rewards (food, water, sex, etc.) are not usually abused because they are tied to the
motivational state of the organism.
Food is one of the natural things that activates our reward center.
Food ? there is a homeostatic mechanism that is tied to blood glucose, leptin from fat cells, etc.
When you need energy ? you experience hunger.
This makes you go get food…….
You eat food ? and you are happy.
Hunger ―creates‖ the rewarding properties of food.
When the hunger is satiated the food is no longer rewarding ? it may even become aversive.
?NO REGULATION OF DRUG REINFORCERS
In a normal brain there would be no ―need‖ for drugs.
Plus, there is no ―detector‖ other than the ―need‖ to relieve stress.
Here is where a person can choose.
If the person makes a bad choice and decides to take drugs…..then the drugs will stop the brain
from working normally…..the brain gets confused because something is activating the reward
center….but the reward center is getting shut off.
The brain ―likes‖ what is going on with the drugs….so the brain, which controls your body….tells
your body to do things to get drugs.
Your brain is addicted….it has a disease….it craves the drugs.
People who are drug addicts have a disease. They made a bad choice to take the drugs….and the drugs changed there brains.
One of the tools that scientists use to look at your brain and see what drugs are doing to your brain is
called positron emission tomography or a PET scan.
This is similar to an x-ray, but much more sophisticated, a PET scan is used to examine many
different organs including the heart, liver, lungs, and bones, as well as the brain.
PET scans let us look at the activity of your brain. It shows us your brain working.
The PET scan allows one to see how the brain uses glucose; glucose provides energy to each
neuron so it can perform work.
?PET OF ADDICT
This is a normal awake person.
The red colors mean that your brain is working (point our all the red in the picture).
Here is a brain of someone who is addicted to cocaine (show the areas on the normal brain that are
red and the yellow – which means the brain is not working the same).
This person is a cocaine addict and this is what happens when they are taking cocaine.
So, cocaine is not only affecting the reward center. It is affecting lots of other areas of the brain as
Taking cocaine changes your brain.
This PET scan shows us that once addicted to a drug like cocaine, the brain is affected for a
long, long time. In other words, once addicted, the brain is literally changed.
In this slide, the level of brain function is indicated in yellow. The top row shows a normal-
functioning brain without drugs. You can see a lot of brain activity. In other words, there is a lot of
The middle row shows a cocaine addict’s brain after 10 days without any cocaine use at all.
Question: What is happening here?
Less yellow means less normal activity occurring in the brain—even after the cocaine abuser has
abstained from the drug for 10 days.
The third row shows the same addict’s brain after 100 days without any cocaine. We can see a
little more yellow, so there is some improvement— more brain activity—at this point. But the
addict’s brain is still not back to a normal level of functioning. . . more than 3 months later.
Scientists are concerned that there may be areas in the brain that never fully recover from drug
abuse and addiction.
Cocaine is not the only drug that hurts your brain.
In this experiment, scientists were looking at the neurons in the brains of monkeys.
Scientists examined the brains for the presence of serotonin, one of the neurotransmitters that the
neurons use to ―talk‖ to each other.
Here is what the normal animal’s brain looks like.
All of these are the axons of the neurons that the brain uses to communicate.
Here is an animal that was given ecstasy twice a day for 4 days.
The scientists waited for 2 weeks and then looked at the neurons.
Here is another animal that was given ecstasy and then the scientists looked at the brain after 7 years.
The brain has tried to fix itself, but the cells are still damaged.
?DRUGS HURT YOUR BODY TOO!
Drugs not only hurt your body, but they hurt other parts of your body too.
We know that the stress that your brain produces when it is addicted also changes our immune
Our immune system is what helps our bodies fight off infections.
Stress produces increases in neuroendocrine function – hypercortisol ? bad.
Increases in neurotransmitter activity – leads to decreases in receptors, increases in cAMP,
decreases in BDNF (brain derived neurotrophic factor).
This causes changes in immune function –
Decreases in lymphocytes – so we don’t produce antibodies to fight infections.
Increases in phagocytes ? which release inflammatory cytokines ? bad news.
So, now our bodies can’t fight infections and bad chemicals are being released that hurt our bodies
and our brains.
?DIRECT DRUG EFFECTS
Drugs also can also hurt other parts of our bodies, like our heart, kidneys and liver.
Some drugs, like ecstasy, cause increase in our body temperature….that means that all the organs in our body don’t work right.
?DO DRUGS REALLY MAKE YOU HAPPY?
Well, yes at first because they relieve stress.
But then they start to change your brain.
Your brain tries to deal with constantly having to deal with the stress of drugs on board.
It tries get back to normal, but it can’t.
As your brain changes with your drug taking behavior it will ultimately flip a ―switch‖.
Once the switch is flipped and you have a non-addicted brain turned into an addicted brain.
Addiction is a brain disease. It is a chronic, relapsing disease.
Now, drugs don’t make you happy – nothing makes you happy.
Lot of other things can make you happy and relieve stress rather than taking drugs.
Here are some examples.
?OTHER STRESS RELIEVERS
QUESTION: What are some other ways that you can think of to relieve stress?
That is my presentation