Module 3.3

Question 1

Why are our brains so sensitive to plant chemicals?

Answer 1

Because most plants evolve chemicals that either attract or repel insects and those chemicals have an effect on other species too, including humans.

Question 2

What is an agonist?

Answer 2

An agonist is a drug that enhances the effects of a neurotransmitter.

Question 3

What is an antagonist?

Answer 3

a drug that decreases the effects of a neurotransmitter

Question 4

List 6 way in which drugs may effect synaptic function.

Answer 4

1. increase/decrease the synthesis of a neurotransmitter
2. cause its vesicles to leak
3. increase its release
4. decrease its reuptake
5. block its breakdown into inactive chemicals
6. act on the postsynaptic receptors

Question 5

What is affinity?

Answer 5

A drug has affinity for a receptor if it binds to it

Question 6

Describe nicotine’s effect on dopamine. How are nucleus accumbens cells altered after repeated nicotine exposure?

Answer 6

It increases dopamine at the nucleus accumbens. It causes nucleus accumbens cells to become less responsive.

Question 7

Describe opiates’ indirect effect on dopamine.

Answer 7

Opiates cause the brain to release endorphins that activate dopamine release

Question 8

What are the psychological and physical effects of marijuana?

Answer 8

Intensified sensory experiences, an illusion that time has slowed down, cognitive and memory impairment

Question 9

What are the indirect effects of cannabinoids on dopamine?

Answer 9

They increase the activity of neurons that release dopamine.

Question 10

What neurotransmitter is affected by hallucinogenic drugs?

Answer 10

serotonin

Question 11

What type of receptor is made more responsive by alcohol? What other neurotransmitters are affected?

Answer 11

The GABA receptor is made more responsive. Other NTs that are affected are dopamine and opiate receptors.

Question 12

List the differences between Type I and Type II Alcoholism.

Answer 12

Type I occurs in people older than 25 gradually and they do not have relatives who abuse alcohol. Type II occurs in people younger than 25 with a rapid onset and most have close relatives that are alcoholics.

Question 13

Describe the evidence of a genetic risk for alcoholism.

Answer 13

People with a longer version of the gene that controls the dopamine type 4 receptor report needing a larger amount of alcohol because they have less sensitive receptors. Another gene is one that makes people more impulsive.

Question 14

How does the prenatal environment affect risk for alcoholism?

Answer 14

The more alcohol a mother drinks during pregnancy, the more likely the child will develop alcoholism.

Question 15

Describe the development of tolerance.

Answer 15

After repeated use, pleasure decreases and tolerance develops. This causes people to be less responsive to alcohol and other reinforcement.

Question 16

Describe the metabolism of alcohol.

Answer 16

The liver metabolizes alcohol to acetaldehyde. The acetaldehyde dehydrogenase converts the acetaldehyde to acetic acid, which the body uses for energy.

Question 17

What is the biochemical effect of Antabuse? What is its physiological effect when combined with alcohol use?

Answer 17

It antagonizes the effects of acetaldhyde dehydrogenase by binding to its copper ion. It makes you sick.

Question 18

What are two other medications to treat alcoholism? How do they work?

Answer 18

Revia and Campral. Revia blocks opiate receptors and makes alcohol use less pleasurable. Campral helps with alcohol withdrawal by antagonizing the receptors for glutamate (the brain’s main excitatory transmitter)

Question 19

What is used to treat opiate addiction? Does it end addiction?

Answer 19

Methadone is used to treat opiate addiction. It doesn’t end the addiction.

Question 20

What is efficacy?

Answer 20

a drug’s tendency to activate a receptor

Question 21

How were the brian mechanisms of please and reinforcement discovered?

Answer 21

Two psychologists put an electrode in the septum in a rat’s brain and whenever they stimulated that part, the rat responded favorably.

Question 22

Which brain area is especially important for reinforcement and addiction?

Answer 22

nucleus accumbens

Question 23

What other activities besides drugs effect the nucleus accumbens?

Answer 23

sex, gambling, video games

Question 24

What is a common neural mechanism for nearly all abused drugs?

Answer 24

The release of of dopamine and norepinephrine

Question 25

How do amphetamine and cocaine affect dopamine?

Answer 25

They increase the accumulation of dopamine in the synaptic cleft

Question 26

What causes the “crash” after amphetamine or cocaine?

Answer 26

The excess dopamine washes away from the synapse faster than the presynaptic cell makes more to replace it

Question 27

How does Ritalin work? Is it safe for children? Why or why not?

Answer 27

It blocks the reuptake of dopamine. It is safe for children because they are less likely to use drugs later, if they take Ritalin.

Question 28

How does MDMA (ecstasy) affect neurotransmitters?

Answer 28

In lower doses, it increases dopamine. In larger doses, it increases serotonin.

Question 29

What evidence points to long-term brain damage after use of ecstasy?

Answer 29

Studies on rodents show that repeated large doses damage neurons that contain serotonin

Question 30

Addictive drugs increase ________ in the __________.

Answer 30

dopamine; nucleus accumbens

Question 31

Repeated use of ________ reorganizes the nucleus accumbens so that other stimulation is less rewarding and the drug is more rewarding

Answer 31

addictive drugs

Question 32

Amphetamines and cocaine are

Answer 32

dopamine agonists

Question 33

MDMA (ecstasy) in low doses stimulates ______; in high doses stimulates ______

Answer 33

dopamine; serotonin

Question 34

treats addiction to opiates

Answer 34

methadone

Question 35

Methadone treats addiction with ____

Answer 35

addiction