![Serotonergic neurons](https://upload.wikimedia.org/wikipedia/commons/8/82/Serotonergic_neurons.svg)
A serotonin pathway identifies aggregate
projections from neurons which synthesize and communicate the monoamine neurotransmitter
serotonin. These pathways are relevant to different psychiatric and neurological disorders.
Pathways
Function
Given the wide area that the many serotonergic neurons innervate, these pathways are implicated in many functions, as listed above. The caudal serotonergic nuclei heavily innervate the spinal cord,
medulla
Medulla or Medullary may refer to:
Science
* Medulla oblongata, a part of the brain stem
* Renal medulla, a part of the kidney
* Adrenal medulla, a part of the adrenal gland
* Medulla of ovary, a stroma in the center of the ovary
* Medulla of t ...
and
cerebellum. In general, manipulation of the caudal nuclei(e.g. pharmacological, lesion, receptor knockout) that results in decreased activity decreases movement, while manipulations to increase activity cause an increase in motor activity. Serotonin is also implicated in sensory processing, as sensory stimulation causes an increase in extracellular serotonin in the
neocortex. Serotonin pathways are thought to modulate eating, both the amount as well as the motor processes associated with eating. The serotonergic projections into the hypothalamus are thought to be particularly relevant, and an increase in serotonergic signaling is thought to generally decrease food consumption (evidenced by
fenfluramine
Fenfluramine, sold under the brand name Fintepla, is a serotonergic medication used for the treatment of seizures associated with Dravet syndrome and Lennox–Gastaut syndrome.https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/212102s003lb ...
, however, receptor subtypes might make this more nuanced). Serotonin pathways projecting into the limbic forebrain are also involved in emotional processing, with decreased serotonergic activity resulting in decreased cognition and an emotional bias towards negative stimuli. The function of serotonin in mood is more nuanced, with some evidence pointing towards increased levels leading to depression, fatigue and sickness behavior; and other evidence arguing the opposite.
See also
*
Dopaminergic pathways
Dopaminergic pathways (dopamine pathways, dopaminergic projections) in the human brain are involved in both physiological and behavioral processes including movement, cognition, executive functions, reward, motivation, and neuroendocrine control. ...
References
{{Neurotransmitter systems
Neurotransmitters