Serotonin/Dopamine

Question 1

5-HT1A

Answer 1

Effect: Mood, cognitive function, neuroendocrine function, inhibition of 5-HT release

Drug: Buspirone (agonist)

Clinical Disorder: anxiety, depression

Question 2

5-HT1D

Answer 2

Effect: Vasoconstriction, inhibition of NT release

Drug: Sumatriptan (inhibition of inflammatory mediator release, cerebrovasoconstriction)

Clinical disorder: Migraine (prophylactic)

Question 3

5-HT2A/2C

Answer 3

Effect: Hallucination, inhibits DA release

Drug: Trazodone (serotonin antagonist reuptake inhibitor aka SARI, blocks side effects associated with SSRIs, ie insomnia and sexual dysfunction)
Risperidone (5-H2A/D2/3 antagonist, supressed DA release in mesolimbic aka reward pathway to stop hallucinations and increased DA release in mesocortical pathway to stop flat affect)

Clinical disorder: depression, schizophrenia

Question 4

5-HT3

Answer 4

Effect: Gut motility, nausea, vomiting

Drug: Ondansetron (blocks receptor that stimulates vagal efferents/activates emetic center. Well-tolerated)

Clinical disorder: Chemotherapy-induced emesis

Question 5

5-HT4

Answer 5

Effect: Gut motility

Drug: Mosapride (not in US, but stimulates relase of Ach into myenteric plexus)

Clinical disorder: GI disorders

Question 6

5-HT transporter

Answer 6

Effect: Removal of 5-HT from synapse

Drug: Fluoxetine, sertraline (increases 5-HT release which initially causes self-inhibition but eventually 1a receptors desensitize and allows more serotonin release)

Clinical disorder: depression, panic disorder, OCD, PTSD, social phobia

Question 7

Dopamine pathway

Answer 7

L-phenylalanine -> L-Tyrosine —- (tyrosine hydroxylase) –> L-DOPA

Question 8

Rate limiting enzyme in DA pathway

Answer 8

Tyrosine hydroxylase