Neurotransmitters II

Question 1

Give examples of catecholamines

Answer 1

Dopamine, noradrenaline, adrenaline

Question 2

What is the more common name for 5-HT?

Answer 2

Serotonin

Question 3

What is acetylcholine associated with?

Answer 3

• Memory
• Coordination
• Sleep cycle
• Mood
• Aggression

Question 4

Reaction to form ACh

Answer 4

Acetyl CoA + Choline ——–> Ach

Requires choline acetyltransferase

Question 5

Reaction to break down ACh

Answer 5

Ach ———> Choline + Acetic acid

Requires acetylcholinesterase

Question 6

Which neurotransmitter is lost in Alzheimer’s?

Answer 6

Acetylcholine

Question 7

3 ways to interfering with ACh

Answer 7

• Prevent release
• AChE inhibitors
• Block ACh receptors

Question 8

Which organism can cause botulism and prevent the release of ACh?

Answer 8

Black widow spider

Question 9

Example of chemical that blocks nicotinic ACh receptors

Answer 9

Curare

Question 10

Example of chemical that blocks muscarinic ACh receptors

Answer 10

Atropine

Question 11

Difference between muscarinic and nicotinic ACh receptors

Answer 11

Muscarinic receptors are G-protein couple

Nicotinic receptors are ligand-gatedd

Question 12

What is the catecholamine system?

Answer 12

Regions of nervous system associated with movement, mood, attention, visceral function

Question 13

What can tyrosine be converted to? Give example of well-known middle man

Answer 13

Epinephrine

Dopamine

Question 14

Symptoms of Parkinson’s disease

Answer 14

• Temor
• Rigidity
• Monotonous slurred speech
• Akinesia

Question 15

Do people suffering from Parkinson’s disease lose sensation?

Answer 15

No

Question 16

What is the pathology of Parkinson’s disease?

Answer 16

Deeneration of substantial nigra

- Use dopamine for imaging in PET scan

Question 17

Nigrostitial pathway

Answer 17

Striatum can be considered as a system that inhibits motor function
Dopamine via D2 receptors inhibits cells of striation - disinhibition
In Parkinson’s inhibition is lost therefor, increase in inhibition of motor function from striatum

Question 18

What does the striatum inhibit?

Answer 18

Motor function

Question 19

What inhibits the striatum in normal function?

Answer 19

Dopamine via D2 receptors

Question 20

Treatment of Parkinson’s disease

Answer 20

• L-Dopa
• Reserpine
• Amphetamine
• Cocaine
• D2 agonists
• MAO(B) inhibitors

Question 21

How can cocaine treat Parkinson’s disease?

Answer 21

Blocks reuptake so increases dopamine stimulation. Can also treat schizophrenia

Question 22

L-Dopa treatment

Answer 22

Use perisperhal DDC inhibitor to stop side effects but long-term treatments will lead to problems as tolerance develops

Question 23

What is chronic L-Dopa syndrome? What is it caused by?

Answer 23

Dopa-induced dyskinesias fluctuating with sudden and severe immobility
Caused by long-term use of L-dopa as treatment

Question 24

What is dyskinesia?

Answer 24

Abnormality/Impairment of voluntary movement

Question 25

What is the dopamine system composed of?

Answer 25

Dopamine and the cortical and limbic system

Question 26

What do dopamine neurones inhibit the secretion of from the pituitary gland?

Answer 26

Prolactin

Question 27

What can the overproduction of prolactin lead to?

Answer 27

Gynaecomastia (over-enlargement of breasts) | Galactorrhoea (spontaneous flow of milk)

Question 28

What does the noradrenaline system arise from?

Answer 28

Locus coerulus

Question 29

What metabolises catecholamines?

Answer 29

- Catechol-O-methyltransferase (COMT) in cytoplasm | - Monamine oxidase (MAO) on outer mitochondrial membrane

Question 30

Where can you find MAO and what do they metabolise?

Answer 30

Outer mitochondrial membrane, liver, gut | Metabolise catecholamies

Question 31

Example of transmitter that MAO-A breaks down

Answer 31

Noradrenealine and serotonin

Question 32

Example of transmitter that MAO-B breaks down

Answer 32

Dopamine

Question 33

What can MAO inhibitors be used to treat? How do these work

Answer 33

- Depression (inhibition of MAO leads to increase in NA and serotonin) - Parkinsons (inhibition of MAO leads to increase in DA)

Question 34

What is 5-HT released by?

Answer 34

Raphe nuclei in the brainstem

Question 35

What is released by the raphe nuclei in the brainstem?

Answer 35

Serotonin

Question 36

Treatment of depression

Answer 36

- Tricyclics - Specific serotonin reuptake inhibitors i.e. fluoxetine - MAO-A inhibitiors

Question 37

Why are tricyclics used to treat depression?

Answer 37

Block reuptake of 5-HT and NA

Question 38

MAO inhibitors and the cheese effect

Answer 38

MAO breaks down dietary tyramine which is sympathomimetic | MAO-I ---> hypertensive crisis

Question 39

How can tyramine affect blood flow?

Answer 39

Cannot pass blood-brain barrier

Question 40

Some neurotransmitter antagonists inhibit transmitter re-uptake: true or false?

Answer 40

True

Question 41

In the brain, a neurotransmitter can have more than one mode of action on postsynaptic cells: true or false?

Answer 41

True

Question 42

The arrival of an action potential at a synapse causes the emptying of more than 90% of all the synaptic vesicles in the bouton: true or false?

Answer 42

False, the action potential a few milliseconds behind needs to release some vesicles

Question 43

What is the major inhibitory neurotransmitter in the brainstem and spinal cord?

Answer 43

Glycine