CH. 6 Serotonin

Question 1

how is serotonin system wired

Answer 1

cell bodies in the raphe nucleus (B7, B8)
axon projections similar to NE, more than DA

Question 2

what type of monoamine is serotonin

Answer 2

indolamine

Question 3

how is serotonin synthesized

Answer 3

tryptophan becomes 5-HTP
5-HTP becomes 5-HT (serotonin)

Question 4

what enzyme converts tryptophan to 5-HTP

Answer 4

tryptophan hydroxylase

Question 5

what enzyme converts 5-HTP to 5-HT?

Answer 5

AADC

Question 6

what other NT does AADC enzyme work on?

Answer 6

dopamine

Question 7

what types of cells is tryptophan hydroxylase found in?

Answer 7

only serotonergic ones

Question 8

what does PCPA do?

Answer 8

irreveresibly inhibits tryptophan hydroxylase to prevent 5-HT synthesis

Question 9

which step in serotonin synthesis is the rate limiting one?

Answer 9

tryptophan to 5-HTP vua tryptophan hydroxylase

Question 10

what is 5HT synthesis dependent on? why?

Answer 10

the ratio of tryptophan to other amino acids in the blood
they use the same transporter across the BBB so they compete for it

Question 11

how can you indirectly reduce 5TH synthesis?

Answer 11

by giving aa cocktail not containing tryptophan

Question 12

what kind of diet would increase tryptophan ratio in the blood? why?

Answer 12

high carb
increased insulin removes aas except tryptophan from blood for protein synthesis

Question 13

what kind of diet would decrease tryptophan ratio in the blood? why?

Answer 13

high protein
liver activation starts protein synthesis who mainly use tryptophan

Question 14

what behavioural effects can reducing serotonin have

Answer 14

depression remission
impaired impulse control

Question 15

vesicle transporter protein for 5HT

Answer 15

VMAT2

Question 16

what kind of autoreceptors does serotonin have? what do they effect?

Answer 16

presynaptic- reduce 5HT vesicle release
somatodendritic- slow firing rate

Question 17

how is 5HT removed from the synapse?

Answer 17

by serotonin reuptake transporter

Question 18

what is the metabolite of 5HT

Answer 18

5-HIAA

Question 19

what enzyme metabolizes 5HT?

Answer 19

MAO

Question 20

what drugs work like amphetamines but are more selective for serotonin? how are they similar to amphetamines?

Answer 20

fenfluramine
MDMA
reverse reuptake transporters

Question 21

fenfluramine effect

Answer 21

appetite surpression
cardiovascular effects

Question 22

MDMA use/effects

Answer 22

recreational drug
euphoria
therapeutic for PTSD

Question 23

what do SSRIs do?

Answer 23

blocks SERT

Question 24

example of an SSRI

Answer 24

fluoxetine

Question 25

what are SSRIs treatment function?

Answer 25

antidepressants

Question 26

how many 5HT receptor sub types are there? how many families?

Answer 26

14 7

Question 27

which receptor familiy is not metabotropic?

Answer 27

3

Question 28

what is the selectivity of available drugs like on serotonin receptors?

Answer 28

selective across families, non-selective within families

Question 29

what is 5HT1a receptors function?

Answer 29

inhibits cAMP hyperpolarizes cell (increase opening of K+ channels

Question 30

where in the brain are 5HT1a receptors postsynaptic?

Answer 30

forebrain regions

Question 31

where in the brain are 5HT1a receptors somatodendritic autoreceptors?

Answer 31

raphe nucleus

Question 32

5HT1a receptors agonists

Answer 32

8-OHDPAT Buspirone

Question 33

what 5HT1a receptor agonist is a full agonist?

Answer 33

8-OHDPAT

Question 34

what 5HT1a receptor agonist is a partial agonist?

Answer 34

buspirone

Question 35

what do 5HT1a receptor agonists do?

Answer 35

stimulate postynapse reduce 5HT release

Question 36

5HT1a receptor antagonist

Answer 36

WAY-100635

Question 37

5-HT1b/d receptor function

Answer 37

presynaptic autoreceptor

Question 38

5-HT2a receptor function

Answer 38

postsynape receptor activating the phosphoinositide 2nd messenger system

Question 39

what other receptor is the 5-HT2a receptor similar to?

Answer 39

a1 adrenergic receptor

Question 40

5-HT2a receptor agonist

Answer 40

DOI

Question 41

DOI effect

Answer 41

hallucinogenic

Question 42

5-HT2a receptor antagonist

Answer 42

ketanserin

Question 43

what is the general overall function of serotonin

Answer 43

to surpress certain patterns of behaviour

Question 44

how to investigate serotonin function in humans

Answer 44

compare CSF 5-HIAA metabolites with traits/disorders response to receptor agonists/antagonists, SSRIs correlate disorders and SERT/5-HT receptor genetic polymorphisms

Question 45

how to investigate serotonin function in animals

Answer 45

lesion 5-HT neurons KO different 5HT receptors delete 5-HT producing enzyme psychopharmacological studies

Question 46

studied functions of serotonin

Answer 46

satiety anxiety aggression impulsivity

Question 47

serotonin's role in hunger

Answer 47

acts as short term satiety signal increases as we eat

Question 48

what brain area is serotonin using to affect hunger

Answer 48

disinhibits paraventricular hypothalamus neurons

Question 49

what causes hypophagia

Answer 49

SSRIs 5HT releasers 5HT1b/2c receptor agonists

Question 50

how do SSRIs shift hunger

Answer 50

reduce food consumed per meal shift preference away from fatty foods

Question 51

what causes hyperphasia

Answer 51

reducing 5-HT release 5HT1a agonists (autoreceptor)

Question 52

how does 5-HT1a postynaptic receptor affect anxiety

Answer 52

activation reduces anxiety

Question 53

what does buspirone treat

Answer 53

anxiety

Question 54

how do 5HT2a/2c receptors affect anxiety

Answer 54

increases anxiety

Question 55

what brain region is 5HT modulating for stress?

Answer 55

BNST

Question 56

how does serotonin affect aggression?

Answer 56

low serotonin increases aggression

Question 57

how is aggression tested in animals

Answer 57

resident-intruder paradigm

Question 58

what role do 5HT1a/b receptors have on aggression

Answer 58

reduce aggression through actions on the postsynapse

Question 59

how does serotonin affect impulsivity

Answer 59

controls ability to put the brake on impulsive responses

Question 60

what receptor is responsible for reducing impulsivity

Answer 60

5HT2c