Serotonin (5-Hydroxytryptamine, 5-HT)is a neurotransmitter. There is a reuptake route available to some presynaptic serotonergic neurons. High levels of serotonergic function in some parts of the brain are characteristic of falling in love. Serotonin promotes vasoconstriction and is mainly found in the enterochromaffin cells of the gastrointestinal tract. It may also help mediate increased blood brain barrier permeability in immobilisation and swimming stress.
A number of associated compounds can stimulate or depress serotonin receptors. Most serotonin receptor subtypes are coupled to G-proteins that affect the activities of either adenylate cyclase or phospholipase.
Excessive stimulation of the serotonergic system can lead to serotonin syndrome.
Serotonin receptor subtypes include:
- 5HT3 - ion channel regulation
- 5HT6 - limbic system - high affinity for antidepressant drugs
- 5HT7 - limbic system
- ↑ Sharma HS, Dey PK. Influence of long-term immobilization stress on regional blood-brain barrier permeability, cerebral blood flow and 5-HT level in conscious normotensive young rats. Journal of the neurological sciences. 1986 Jan; 72(1):61-76.
- ↑ Sharma HS, Westman J, Navarro JC, Dey PK, Nyberg F. Probable involvement of serotonin in the increased permeability of the blood-brain barrier by forced swimming. An experimental study using Evans blue and 131I-sodium tracers in the rat. Behavioural brain research. 1995 Dec 14; 72(1-2):189-96.
- ↑ Rothman RB, Baumann MH, Savage JE, Rauser L, McBride A, Hufeisen SJ, et al. Evidence for possible involvement of 5-HT(2B) receptors in the cardiac valvulopathy associated with fenfluramine and other serotonergic medications. Circulation 2000;102:2836-41.