Monoamine Neurotransmitters Flashcards
Where is serotonin synthesized in the brain and from what amino acid?
Synthesized from the amino acid tryptophan in brainstem dorsal raphe nucleus
What is the rate limiting step in the synthesis of serotonin?
Hydroxylation of tryptophan by tryptophan hydroxylase is rate limiting step
Serotonin levels are DECREASED in which conditions?
- Depression
- Anxiety d/o
- Insomnia
- Violent behaviors
- Impulse control
- Suicide
Serotonin levels are INCREASED in which conditions?
- Serotonin syndrome
- Tumors (i.e. Carcinoid tumors)
How is Norepinephrine formed?
Formed from hydroxylation of dopamine by dopamine beta hydroxylase
Where is norepinephrine primarily found in the brain?
Found primarily in nucleus locus ceruleus in midbrain, actions carried out via binding of NE to adrenergic receptors
(released by adrenal medulla as a hormone)
Norepinephrine levels are DECREASED in which conditions?
- Depression
- ADHD
Norepinephrine levels are INCREASED in which conditions?
- Anxiety disorders (GAD, panic d/o)
How is dopamine synthesized?
Synthesized by removing a carboxyl group from L-Dopa by Dopa decarboxylase
What is dopamine’s major metabolite?
Homovanillic acid (HVA) => formed by MAO and COMT enzymes
Dopamine has a key role in which domains?
- Motor control
- Memory
- Motivation
- Arousal/attention
- Reward/ pleasure
- Perception of pain
Dopamine is DECREASED in which conditions?
- Depression
- Parkinson’s disease
- ADHD
- Restless leg syndrome
Dopamine is INCREASED in which conditions?
- Mania
- Psychotic disorders
