II. Physiology
-
Neurotransmitter
- Motor control
- Pain Perception
- Sympathetic Nervous System outflow
- Synthesis from Essential Amino Acid L-Tryptophan
- Serotonin is released from inhibitory Neurons originating in the pons and Midbrain raphe nuclei
- Serotonin is also stored in the Small Intestine enterochromaffin cells (contains 90% of the body's Serotonin stores)
- Serotonin Receptors
- Serotonin-1 Receptor (5-HT-1) Activity
- Anti-depressant effect
- Serotonin-2 Receptor (5-HT-2) Activity
- Inhibits 5-HT-1 Receptor
- Sexual Dysfunction
- Insomnia
- Anxiety
- Serotonin-3 Receptor (5-HT-3) Activity
- Gastrointestinal symptoms
- Headache
- Serotonin-1 Receptor (5-HT-1) Activity
III. Medications: Increase Serotonin levels
- Increased Serotonin synthesis: L-Tryptophan
- Decrease Serotonin metabolism: MAO Inhibitors
- Increase Serotonin release: Amphetamines, Cocaine
- Inhibit Serotonin uptake
- Direct Serotonin Receptor Agonists: Buspar, Imitrex, Lysergic Acid Diethlyamide (LSD)
- Dopamine Agonists: Amantadine, Wellbutrin, Levodopa
- Other Non-specific Serotonin increase: Lithium
IV. References
- Olson (2020) Clinical Pharmacology, MedMaster, Miami, p. 35