It has no anticholinergic properties and is believed to be devoid of any activity on dopamine, serotonin or histamine receptors.

Noradrenergic and specific serotonergic antidepressants ( NaSSAs ) form a newer class of antidepressants which purportedly work to increase norepinephrine ( noradrenaline ) and serotonin neurotransmission by blocking presynaptic alpha-2 adrenergic receptors while at the same time blocking certain serotonin receptors.

Like the other atypical antipsychotics, it is believed to have antagonist activity at dopamine and serotonin receptors in the brain.

Some also block or partially block serotonin receptors ( particularly 5HT < sub > 2A, C </ sub > and 5HT < sub > 1A </ sub > receptors ): ranging from risperidone, which acts overwhelmingly on serotonin receptors, to amisulpride, which has no serotonergic activity.

The additional effects on serotonin receptors may be why some of them can benefit the " negative symptoms " of schizophrenia.

Among the neurotransmitter systems with enhanced functions are: GABA < sub > A </ sub >, glycine, serotonin, nicotinic acetylcholine receptors.

# Behavioral and mood regulation: receptors in the mammalian brain bind several different neurotransmitters, including serotonin, dopamine, GABA, and glutamate

GPCRs include receptors for sensory signal mediators ( e. g., light and olfactory stimulatory molecules ); adenosine, bombesin, bradykinin, endothelin, γ-aminobutyric acid ( GABA ), hepatocyte growth factor ( HGF ), melanocortins, neuropeptide Y, opioid peptides, opsins, somatostatin, GH, tachykinins, members of the vasoactive intestinal peptide family, and vasopressin ; biogenic amines ( e. g., dopamine, epinephrine, norepinephrine, histamine, glutamate ( metabotropic effect ), glucagon, acetylcholine ( muscarinic effect ), and serotonin ); chemokines ; lipid mediators of inflammation ( e. g., prostaglandins, prostanoids, platelet-activating factor, and leukotrienes ); and peptide hormones ( e. g., calcitonin, C5a anaphylatoxin, follicle-stimulating hormone ( FSH ), gonadotropin-releasing hormone ( GnRH ), neurokinin, thyrotropin-releasing hormone ( TRH ), cannabinoids, and oxytocin ).

Several radiotracers ( i. e. radioligands ) have been developed for PET that are ligands for specific neuroreceptor subtypes such as raclopride and fallypride for dopamine D2 / D3 receptors, McN 5652 and DASB for serotonin transporters, or enzyme substrates ( e. g. 6-FDOPA for the AADC enzyme ).

A recent study on serotonin receptors and religiosity suggests a correlation between low density of serotonin receptors and intense religious experiences.

Serotonin syndrome is not an idiosyncratic drug reaction ; it is a predictable consequence of excess serotonergic activity at central nervous system ( CNS ) and peripheral serotonin receptors.

In addition to serotonin receptor activity, mescaline also stimulates the dopamine receptors.

Antidepressants reduce symptoms of mood disorders primarily through the regulation of norepinephrine and serotonin ( particularly the 5-HT receptors ).

Classical or serotonergic psychedelics ( agonists for the 5-HT < sub > 2A </ sub > serotonin receptors ) include LSD, psilocybin ( the active constituent of psilocybin mushrooms, commonly known as " magic mushrooms "), mescaline ( the active constituent of peyote ), and DMT ( the active constituent of ayahuasca and potentially an endogenous psychedelic compound ).

Tramadol is structurally closer to venlafaxine than to codeine and delivers analgesia by not only delivering " opiate-like " effects ( through mild agonism of the mu receptor ) but also by acting as a weak but fast-acting serotonin releasing agent and norepinephrine reuptake inhibitor.

SSRIs are said to work by preventing the reuptake of serotonin ( also known as 5-hydroxytryptamine, or 5-HT ) by the presynaptic neuron, thus maintaining higher levels of 5-HT in the synapse.

Changing the balance of serotonin and norepinephrine would help the brain cells send and receive messages, therefore boosting the mood, which also is the main reason why these types of medications are called dual reuptake inhibitors.

Selective serotonin reuptake inhibitors are likely to be the best choice of pharmacotherapy for many patients with panic disorder, but benzodiazepines are also often used, and some studies suggest that these medications are still used with greater frequency than the SSRIs.

" L-methylfolate ( also formally known as 5-MTHF or Levofolinic acid ), a centrally acting trimonoamine modulator, boosts the synthesis of three CNS neurotransmitters: dopamine, norepinephrine and serotonin.

The locus of the monoamine action of modafinil has also been the target of studies, identifying effects on dopamine in the striatum and nucleus accumbens, noradrenaline in the hypothalamus and ventrolateral preoptic nucleus, and serotonin in the amygdala and frontal cortex.

Contrarily, local application of estrogen has been shown to block the ability of fluvoxamine to slow serotonin clearance, suggesting that the same pathways which are involved in SSRI efficacy may also be affected by components of local estrogen signaling pathways.

Not only does PMA cause the release of serotonin but it also acts as a monoamine oxidase inhibitor, MAOI.

Combining MAO inhibitors with certain legal prescription and over the counter medications can also lead to ( potentially fatal ) serotonin syndrome.

The dopamine hypothesis is now thought to be simplistic, partly because newer antipsychotic medication ( atypical antipsychotic medication ) can be just as effective as older medication ( typical antipsychotic medication ), but also affects serotonin function and may have slightly less of a dopamine blocking effect.

It may also be called serotonin sickness, serotonin storm, serotonin poisoning, hyperserotonemia, or serotonergic syndrome.

Niacin synthesis is also deficient in carcinoid syndrome, because of metabolic diversion of its precursor tryptophan to form serotonin.

Mescaline is also known to bind to and activate the serotonin 5-HT < sub > 2C </ sub > receptor.

Another experiment found that serotonin also reduces the photophobic behavior in Gammarus lacustris.

Dysfunction in serotonin and other monoamine neurotransmitters such as norepinephrine and dopamine has also been centrally implicated in mental disorders, including major depression as well as obsessive compulsive disorder, phobias, posttraumatic stress disorder, and generalized anxiety disorder, although the limitations of a simple " monoamine hypothesis " have been highlighted and studies of depleted levels of monoamine neurotransmitters have tended to indicate no simple or directly causal relation with mood or major depression, although features of these pathways may form trait vulnerabilities to depression.

** serotonin: a neurotransmitter involved in depression also has an inhibitory effect on eating behavior.

It is also suggested by many that endorphins are some of the many chemicals that contribute to runner's high ; other candidates include epinephrine, serotonin, and dopamine.

Piperine enhances the thermogenesis of lipid and accelerates energy metabolism in the body and also increases the serotonin and beta-endorphin production in the brain.

Hyponatremia has been reported in up to 30 % of elderly patients in nursing homes and is also present in approximately 30 % of depressed patients on selective serotonin reuptake inhibitors.

The enteric nervous system also makes use of more than 30 neurotransmitters, most of which are identical to the ones found in CNS, such as acetylcholine, dopamine, and serotonin.

Lysine has a known anxiolytic action through its effects on serotonin receptors in the intestinal tract.

Serotonin syndrome may result from an interaction with certain drugs which increase serotonin activity such as selective serotonin reuptake inhibitors and pethidine ( known as meperidine in the US ).

The exact mechanism is not known, a theory of serotonin dysfunction helps explain how the syndrome presents and how it is to be treated.

Discontinuation of selective serotonin reuptake inhibitors ( SSRIs ), the most commonly prescribed class of antidepressants, ( and the related class serotonin-norepinephrine reuptake inhibitors or SNRIs ) is associated with a particular syndrome of physical and psychological symptoms known as SSRI discontinuation syndrome.

The mechanism of action that produces 2C-T-2 ’ s hallucinogenic and entheogenic effects has not been specifically established, however it is most likely to result from action as a 5-HT < sub > 2A </ sub > serotonin receptor agonist in the brain, a mechanism of action shared by all of the hallucinogenic tryptamines and phenethylamines for which the mechanism of action is known.

Other phenethylamine derivatives substituted with an alkylthio group at the 4 position such as 2C-T-7 and 4-MTA are known to act as selective monoamine oxidase A inhibitors, a side effect which can lead to lethal serotonin syndrome when combined with stimulant drugs.

Venlafaxine may be particularly hazardous to those individuals who are susceptible to both venlafaxine-induced serotonin toxicity ( also known as serotonin syndrome ) and SSRI discontinuation syndrome.

It had already been known for decades that two of the major side-effects of the carcinoid syndrome, in which excessive serotonin is produced endogenously, are valvular disease and pulmonary hypertension.

SNRIs act upon, and increase, the levels of two neurotransmitters in the brain known to play an important part in mood: serotonin, and norepinephrine.

** Tianeptine — paradoxical antidepressant ( considered to be a selective serotonin reuptake enhancer ( SSRE ) ( note that no widely known proof of direct SSRE action exists )), improves mood and reduces anxiety ; action on the NMDA and AMPA receptor, a hypothesized mechanism of action, based on tianeptine's effect of promoting stress-associated impaired neuroplasticity ; it enhances the extracellular concentration of dopamine in the nucleus accumbens and modulates the D < sub > 2 </ sub > and D < sub > 3 </ sub > dopamine receptors, but this effect is modest and almost certainly indirect.

The mechanism that produces 2C-T-21 ’ s hallucinogenic and entheogenic effects has not been specifically established, however it is most likely to result from action as a 5-HT < sub > 2A </ sub > serotonin receptor agonist in the brain, a mechanism of action shared by all of the hallucinogenic tryptamines and phenethylamines for which the mechanism of action is known.

Substitued phenethylamines with known physiological effects include sympathomimetics ( including adrenergic uptake inhibitors ), dopamine agents ( including dopamine uptake inhibitors ), serotonin agents ( including serotonin agonists and serotonin uptake inhibitors ), adrenergic agents ( including adrenergic alpha-agonists and adrenergic beta-agonists ), hallucinogens and neuroprotective agents.

The serotonin receptors are known to regulate longevity and behavioral aging in the nematode, Caenorhabditis elegans.

The mechanism that produces 2C-T-4 ’ s hallucinogenic and entheogenic effects has not been specifically established, however it is most likely to result from action as a 5-HT < sub > 2A </ sub > serotonin receptor agonist in the brain, a mechanism of action shared by all of the hallucinogenic tryptamines and phenethylamines for which the mechanism of action is known.

Other phenethylamine derivatives substituted with an alkylthio group at the 4 position such as 2C-T-7 and 4-MTA are known to act as selective monoamine oxidase A inhibitors, a side effect which can lead to lethal serotonin syndrome when they are combined with stimulant drugs.

Other phenethylamine derivatives substituted with an alkylthio group at the 4 position such as 2C-T-7 and 4-MTA are known to act as selective monoamine oxidase A inhibitors, a side effect which can lead to lethal serotonin syndrome when they are combined with stimulant drugs.