Serotonergic/NE

Question 1

what are the other names for serotonin?

Answer 1

5-HT
5-hydroxytryptamine

Question 2

what amino acid is serotonin synthesized from?

Answer 2

tryptophan

Question 3

what kind of transporter involved in getting serotonin inside the nerve terminal?

Answer 3

Na+ coupled (with tryptophan) Aromatic L-amino acid transporter.
this is a symporter

Question 4

what happens to tryptophan once inside the nerve terminal?

Answer 4

it gets converted to 5-hydroxytryptophan via Tryptophan Hydroxylase by adding a hydroxyl group
this is a rate-limiting step

Question 5

what happpens after 5-hydroxytryptophan is made?

Answer 5

it gets further converted into 5-hydroxytryptamine aka 5-HT aka Serotonin

Question 6

what enzyme convert 5-hydroxytryptophan to serotonin?

Answer 6

aromatic l-amino acid decarboxylase
by removing a carboxyl forming a monoamine at the end

Question 7

is serotonin a monoamine?

Answer 7

yes

Question 8

is serotonin a catecholamine?

Answer 8

no

Question 9

what transporter transport serotonin into the vesicle?

Answer 9

VMAT powered by V-ATPase
also using a proton gradient

Question 10

is VMAT selective or non-selective?

Answer 10

non-selective
it transport all monoamines

Question 11

what happens when serotonin nerve is activated?

Answer 11

an action potential is generated

Question 12

what happens when an action potential is generated?

Answer 12

Ca2+ influx causing exocytosis –> serotonin release

Question 13

how can serotonin be deactivated after transmission?

Answer 13

reuptake back into the presynaptic nerve terminal via SERT or degraded by MAO

Question 14

how many total number of serotonin receptors are identified?

Answer 14

14

Question 15

how many serotonin receptors are in the brain?

Answer 15

13

Question 16

which serotonin receptor is not in the brain?

Answer 16

5-HT-5B

Question 17

which class of serotonin receptors is the only ion channel receptors?

Answer 17

5-HT3

Question 18

what are the subtype receptors in 5-HT1 class?

Answer 18

5-HT1a, b, d, e, f

Question 19

what are the subtype receptors in 5-HT2 class?

Answer 19

5-HT2a, b, c

Question 20

which G protein is associated with 5-HT1 class?

Answer 20

Gi - inhibitory

Question 21

what happens to G proteins when class 5-HT1 is activated?

Answer 21

Gi activated –> decrease AC –> decrease cAMP –> decrease PKA
Gi activated –> increase K+ efflux
THIS LEADS TO DECREASE NEURONAL ACTIVITY

Question 22

which 5-HT1 receptors is associated with negative feedback mechanism?

Answer 22

5-HT1B is the presynaptic autoreceptors –> negative feedback inhibition

Question 23

what G protein is associated with 5-HT2 receptor class?

Answer 23

Gq - excitatory

Question 24

what happens when 5-HT2 is activated?

Answer 24

Gq activated –> increase PLC –> increase IP3 + increase DAG –> increase cytosolic Ca2+ –> increase PKC
THIS LEADS TO NEURONAL ACTIVITY

Question 25

what amino acid is used to produce NE?

Answer 25

tyrosine