Lecture 15

Question 1

What is psychopharmacology?

Answer 1

The study of how drugs affect the nervous system and behaviour

Question 2

What are psychoactive drugs?

Answer 2

Substances that act to alter mood, thought, behaviour (sugar, caffeine, alcohol)

Question 3

What treatment proved to work well on the frozen addicts?

Answer 3

L-Dopa and Stem Cells extracted from human fetal brains

Question 4

Why doesn’t stem cell implants work well with Parkinsons?

Answer 4

As Parkinson’s is continuous cell loss versus simply lesioning

Question 5

What are psychoactive drugs typically used for?

Answer 5

Management of neurophysical illnesses, recreational use, potential for abuse.

Question 6

What are some routes of administration for drugs?

Answer 6

Injection, inhalation, orally

Question 7

What are the advantages of oral administration?

Answer 7

Safe, easy, and convenient

Question 8

What are the advantages of inhalation?

Answer 8

Quick, less barriers than oral administration (en route to the brain)

Question 9

What are the advantages of injection?

Answer 9

Quick acting, few barriers

Question 10

What are some of the disadvantages of oral administration?

Answer 10

Number of barriers that the drug must pass through (stomach/intestinal lining, blood stream), slow acting

Question 11

What are some of the disadvantages of inhalation?

Answer 11

Damage to lung tissue as a result of exposure.

Question 12

What are some of the disadvantages of injection?

Answer 12

Drugs must be hydrophillic, harder to reverse any negative effects.

Question 13

How do we get substances past the blood-brain barrier?

Answer 13

Have to be small and water-soluble- or go through the areas of the brain not protected by the BBB (pineal gland, pit gland, area postrema).

Question 14

What are some of the mechanisms that catabolize drugs?

Answer 14

Liver** (9/10 times) (cytocrome P450 enzymes), kidneys, intestines.

Question 15

What are some of the ways that excretion may occur?

Answer 15

Urine** (9/10 times), feces, sweat, exhalation, breast milk

Question 16

What is a problem that is happening with Fluoxetine excretion?

Answer 16

Because it is excreted via urine, it ends up in our waterways, and sewage plants are unable to process it. It is now present in high enough levels to alter the behaviours of local fish species (fathead minnows specifically).

Question 17

What is the species typical behaviour of the fathead minnow and how does fluoxetine alter this?

Answer 17

Species typical- Males: build nest AND take care of eggs, females visit nest and lay eggs
Fluoxetine fish- males will attack the females

Question 18

What process does drug action mimic in the neurons?

Answer 18

Neurotransmitters! Synthesis, storage, release, interaction, inactivation, reuptake, degradation

Question 19

What are the 2 effects that drugs can have on the synapse?

Answer 19

Agonists- Enhance functions of the synapse

Antagonists- Block function of the synapse.

Question 20

What are some things that agonists can do?

Answer 20

Increase certain neurotransmitters, promote release of neurotransmitters, stimulate receptors, block inactivation

Question 21

What are some things that antagonists can do?

Answer 21

Block release and receptors.

Question 22

What is tolerance?

Answer 22

A decrease in a response to a drug with the passage of time

Question 23

What was the study done in the 50s on alcohol tolerance?

Answer 23

Gave people alcohol everyday for 13 weeks-population was convicts BECAUSE they should have a BAC of 0. Results: After 15-20 days, BAC levels fell and so did signs of intoxication.

Question 24

What is metabolic tolerance?

Answer 24

The number of enzymes that breakdown alcohol increases.

Question 25

What is cellular tolerance?

Answer 25

Neurons adjust to minimize effects

Question 26

What is learned tolerance?

Answer 26

Learning to cope with daily living under the influence

Question 27

What is sensitization?

Answer 27

Increased responsiveness to successive, equal doses of a drug. Likely to occur as a result of intermittent use of a drug.

Question 28

How did Robinson and Becker study sensitization?

Answer 28

Injected rats with amphetamine every 3-4 days. Found that stimulus novelty and intermittent use in part drives the sensitization response.

Question 29

What are some of the changes that occur at the synapse with drug sensitization?

Answer 29

Increase in the amount of neurotransmitter released, increase in number of receptors present on the post-synaptic membrane, decrease in the rate of transmitter metabolism/reuptake, changes in the number of synapses.

Question 30

What is an example of an adenosinergic drug and what do they do?

Answer 30

Caffeine- most widely used psychoactive substance in the world (80% of US population). Adenosine receptor antagonist (adenosine induces drowsiness). Increase in cAMP=more glucose. Release of dopamine and acetylcholine.

Question 31

What is an example of a cholinergic drug and what do they do?

Answer 31

Nicotine-Activates acetylcholine nicotinic receptors (agonist). Found in tobacco plant, but also potatoes, tomatoes, and eggplants Acetylcholine psychadelics-block or facilitate transmission at ACh synapse (like atropine, which is an agonist) makes you feel like you're flying, associated with witches.

Question 32

What is an example of a GABAergic drug and what do they do?

Answer 32

Benzodiazepines: Diazepam (Valium), Alprazolam (Xanax), Alcohol, sedatives etc. Ramps up inhibition in the body. Alcohol maximizes pore openings, allowing GABA to bind, benzos influence the frequency of the pore opening

Question 33

What is cross-tolerance?

Answer 33

Reduction of response to a novel drug because of tolerance of chemically related drug.