OCB03-2009 SEROTONIN

Question 1

What are the main functions of serotonergic transmission?

Answer 1

Inhibit sensory input

Descending pain inhibition

Question 2

How can serotonin affect morphine?

Answer 2

Decreased serotonin antagonises the effects of morphine

Question 3

What are the two principal serotonergic nuclei?

Answer 3

Rostral raphe nuclei

Caudal raphe nuclei

Question 4

What two monoamine neurotransmitters have a similar distribution in the CNS?

Answer 4

NA

Serotonin

Question 5

Where do the serotonergic neurons project to from the rostral raphe nuclei?

Answer 5

Ascend to cerebral cortex, limbic regions and specifically the basal ganglia

Question 6

Where do the serotonergic neurons project to from the caudal raphe nuclei?

Answer 6

Descend to medulla or to spinal cord

Question 7

What is another name for serotonin?

Answer 7

5-hydroxytryptamine

Question 8

How is 5-hydroxytryptamine formed?

Answer 8

Tryptophan –> 5-hydroxytryptophan by tryptophan hydroxylase

5-hydroxytryptophan –> 5-hydroxytryptamine by aromatic amino acid decarboxylase

Question 9

What can 5-HT be converted to?

Answer 9

Melatonin

5-hydroxyindoleacetic acid by MAOa

Question 10

What can be measured to determine 5-HT transmission in the brain?

Answer 10

5-hydroxyindoleacetic acid (5-HIAA) in ECF

Question 11

How can serotonin be removed from the synapse?

Answer 11

SERT into neurons

ENT into glial cells

Question 12

What type of receptor are serotonin receptors?

Answer 12

All GPCRs except 5-HT3 which is an cation channel

Question 13

What G protein are 5-HT1 receptors coupled to?

Answer 13

Gi

Question 14

What are 5-HT1A receptors involved in?

Answer 14

Sleep

Neuronal inhibition

Anxiety

Feeding

Thermoregulation

Question 15

What are 5-HT1B receptors involved in?

Answer 15

Presynaptic inhibition

Behaviour

Food intake

Question 16

What are 5-HT1D receptors involved in?

Answer 16

Peripheral vasoconstriction

Behaviour

Locomotion

Question 17

What G protein are 5-HT2 receptors coupled to?

Answer 17

Gq/11

Question 18

Where are 5-HT2A receptors found and what are they involved in?

Answer 18

Found in CNS, PNS, smooth muscle and platelets

Neuronal excitation

Behaviour

Platelet aggregation

Vasoconstriction/dilatation

Question 19

Where are 5-HT2B receptors found and what do they do?

Answer 19

Found in the gastric fundus

Muscle contraction

Question 20

What are 5-HT2C receptors involved in?

Answer 20

CSF secretion

Food intake

Question 21

What type of receptor is 5-HT3?

Answer 21

Ligand-gated cation channel

Question 22

What is the 5-HT3 receptor involved in?

Answer 22

Neuronal excitation

Behaviour

Anxiety

Emesis (vomiting)

Question 23

Which 5-HT receptors are Gs-linked?

Answer 23

4, 6, 7

Question 24

What G protein is 5-HT5 coupled to?

Answer 24

Gi

Question 25

What is the 5-HT4 receptor involved in?

Answer 25

GI motility Neuronal excitation

Question 26

What is the 5-HT6 receptor involved in?

Answer 26

Learning and memory

Question 27

What is the 5-HT7 receptor involved in?

Answer 27

Thermoregulation Circadian rhythm

Question 28

What does LSD stand for?

Answer 28

Lysergic acid diethylamide

Question 29

What receptor does buspirone act on and what is it used to treat?

Answer 29

Agonist of 5-HT1A Anxiety

Question 30

What receptor does sumatriptan act on and what is it used to treat?

Answer 30

Agonist of 5-HT1D Migraines

Question 31

What receptor does methylsergide act on and what is it used to treat?

Answer 31

Antagonist of 5-HT2A Migraines

Question 32

What receptor does clozapine act on and what is it used to treat? (5-HT)

Answer 32

Antagonist of 5-HT2A Antipsychotic

Question 33

What receptor does lorcaserin act on and what is it used to treat?

Answer 33

Agonist of 5-HT2C Obesity (decreases food intake)

Question 34

How does cocaine affect 5-HT transmission?

Answer 34

Blocks SERT

Question 35

How do MAOa inhibitors affect 5-HT transmission and what are they used to treat?

Answer 35

Decrease 5-HT metabolism Depression

Question 36

How does fenfluramine affect 5-HT transmission and what is it used to treat?

Answer 36

Increases 5-HT release and blocks SERT Previously treated obesity

Question 37

What type of drugs are prozac (fluoxetine) and fluvoxamine?

Answer 37

SSRI (block SERT) = antidepressant

Question 38

What type of drugs are venlafaxine and duloxetine and what are they used to treat?

Answer 38

SNRI (block SERT more than NET) Depression, anxiety, pain

Question 39

What type of neurons are inhibited by serotonergic neurons in descending pain inhibition?

Answer 39

Spinothalamic neurons