Analysis of information sources in references of the Wikipedia article "Serotonin" in English language version.
Two obstacles effectively prohibit this availability. Serotonin has a free hydroxy group (the 5-hydroxy which is the H of 5-HT). This is a big polar water-loving pimple which denies it any passage across the brain's defensive Maginot Line, the blood-brain barrier. And there is the second problem. There is a exposed amino group, the amine of T of 5-HT, the tryptamine, which is immediately removed by the body's monoamine oxidase enzyme. In short, it is blocked from entry into the brain because it is both too polar and too metabolically fragile.
Ergonovine is a selective and moderately potent tryptaminergic receptor antagonist in various smooth muscles, being only a partially agonistic or antagonistic at tryptaminergic receptors in the central nervous system. In blood vessels the alkaloid is only weakly antagonistic of dopaminergic receptors and partitally agonistic of α-adrenergic receptors. The most pronounced effect of ergonovine is one of direct stimulation of the uterine smooth musculature, resulting in increased muscular tone and an enhancement of the rate and force of rhythmical contractions. This stimulant effect seems to be most closely associated with agonist or partial agonist effects at 5-HT2 receptors. [...] LSD and related hallucinogens are known to interact with brain 5-HT receptors to produce agonist or partial antagonist effects on serotonin activity.
{{cite journal}}: CS1 maint: DOI inactive as of July 2025 (link)Methylergonovine is a serotonergic receptor agonist in the smooth muscle. It is also a weak antagonist of dopaminergic receptors and partial agonist of α-adrenergic receptors.22 Methylergonovine causes uterine contractions and relaxation at low doses, but causes sustained contractions and increased basal tone at high doses.24 The mechanism of action for uterine contraction is not well defined. Uterine contraction is likely produced by methylergonovine agonist effects on the 5-HT2 receptor found in uterine smooth muscle.22 Alternatively, methylergonovine could cause uterine contraction through direct stimulation of the α-adrenergic receptors in the uterus, which has been postulated to lead to calcium mobilization.25
In addition to promoting psychedelic-induced structural neuroplasticity, the intracellular population of 5-HT2ARs might also contribute to the hallucinogenic effects of psychedelics. When we administered a serotonin-releasing agent to wild type mice, we did not observe a HTR. However, the same drug was able to induce a HTR in mice expressing SERT on cortical neurons of the mPFC—a brain region known to be essential for the HTR (49). Thus, activation of intracellular cortical 5-HT2ARs may play a role in the subjective effects of psychedelics. This hypothesis is further supported by previous work demonstrating that a high dose of the serotonin precursor 5-hydroxytryptophan (5-HTP) induces a HTR in WT mice, which can be blocked by an N-methyltransferase inhibitor that prevents the metabolism of 5-HTP to N-methyltryptamines (50). Inhibition of N-methyltransferase failed to block the HTR induced by 5-MeO-DMT (50). Taken together, this work emphasizes that accessing intracellular 5-HT2ARs is important for 5-HT2AR agonists to produce a HTR.
Octopamine and serotonin regulates the activity of the M3 neurons that direct contraction of the pharynx during C. elegans feeding... Soaking Meloidogyne J2 in dsRNA in the presence of ... resorcinol plus serotonin resulted in uptake of solutions and silencing of genes expressed in the intestine and esophageal glands.
p. 231,
The change in the number of several potential neurotransmitters ... such as serotonin... may play an important role in remodeling the CNS during phase change (26, 56, 80).
p. 233,
In the locust S. gregaria, the amount of serotonin in the thoracic ganglia was positively correlated with the extent of gregarious behavior induced by different periods of crowding. A series of pharmacological and behavioral experiments demonstrated that serotonin plays a key role in inducing initial behavioral gregarization (2, 80). However, serotonin is not responsible for maintaining gregarious behavior because its amount in long-term gregarious locusts is less than half that in long-term solitarious locusts (80). In L. migratoria, the injection of serotonin can also slightly initiate gregarious behavior, but serotonin when accompanying crowding treatment induced more solitarious-like behavior than did serotonin injection alone (48). Significant differences in serotonin levels were not found in brain tissues between the two phases of L. migratoria. A recent report by Tanaka & Nishide (97) measured attraction/avoidance behavior in S. gregaria after single and multiple injections of serotonin at different concentrations. Serotonin had only a short-term effect on the level of some locomotor activities and was not involved in the control of gregarious behavior (97). In addition, it is not clear how the neurotransmitter influences this unique behavior, because a binary logistic regression model used in these studies for the behavioral assay focused mostly on only one behavioral parameter representing an overall phase state. Obviously, behavioral phase change might involve alternative regulatory mechanisms in different locust species. Therefore, these studies demonstrate that CNS regulatory mechanisms governing initiation and maintenance of phase change are species specific and involve the interactions between these neurotransmitters.
Given the key roles of aminergic signaling, what are the downstream pathways involved in the establishment of long-term memory? Ott et al. (63) investigated the role of [] protein kinase[] in the phase change in S. gregaria: ... cAMP-dependent protein kinase A (PKA). Through use of pharmacological and RNAi intervention, these authors have demonstrated that PKA... has a critical role in modulating the propensity of locusts to acquire and express gregarious behavior. ... Unfortunately, although a correlation between serotonin and PKA was hypothesized, direct evidence was not provided.
...gregarization is evoked by... tactile stimulation... Tactile stimuli trigger the increase of biogenic amines, particularly serotonin, in the locust nervous system (1, 116); these amines play critical roles in the neurophysiology of locust behavioral phase change.
Table 1 The respective potential peaks for various electroactive biomolecules that are produced or consumed by microbes reported in the literaturea ... Serotonin | Indium tin oxide | +0.67 | 66
Table III: Orally and Parenterally Active Psychotropic Tryptamine Derivatives* [...] Name of Compound: Serotonin [...] Dosage (mg): 100#. Route: Oral. [...] # Cardiovascular and autonomic symptoms; little central activity.
13.9 Indolealkylamines and the CNS in human beings 13.91 Central effects of 5-HT [...]
{{cite book}}: ISBN / Date incompatibility (help); |journal= ignored (help)Unfortunately, except for the intraventricular injections described by Sherwood,7 there have been, thus far, no documented reports of serotonin-induced mental disturbance* in man that are clearly separable from the natural anxiety initiated by the profound peripheral effects such as circulatory disturbance, other autonomic effects, and emesis. [...] 7. SHERWOOD, S, L. 1955. The responses of psychotic patients to intraventricular injections. Proc. Roy. Soc. Med. 48: 855.
Serotonin. [...] 4 patients received this drug in doses of 15 to 75 μg. [...]
In addition to promoting psychedelic-induced structural neuroplasticity, the intracellular population of 5-HT2ARs might also contribute to the hallucinogenic effects of psychedelics. When we administered a serotonin-releasing agent to wild type mice, we did not observe a HTR. However, the same drug was able to induce a HTR in mice expressing SERT on cortical neurons of the mPFC—a brain region known to be essential for the HTR (49). Thus, activation of intracellular cortical 5-HT2ARs may play a role in the subjective effects of psychedelics. This hypothesis is further supported by previous work demonstrating that a high dose of the serotonin precursor 5-hydroxytryptophan (5-HTP) induces a HTR in WT mice, which can be blocked by an N-methyltransferase inhibitor that prevents the metabolism of 5-HTP to N-methyltryptamines (50). Inhibition of N-methyltransferase failed to block the HTR induced by 5-MeO-DMT (50). Taken together, this work emphasizes that accessing intracellular 5-HT2ARs is important for 5-HT2AR agonists to produce a HTR.
Octopamine and serotonin regulates the activity of the M3 neurons that direct contraction of the pharynx during C. elegans feeding... Soaking Meloidogyne J2 in dsRNA in the presence of ... resorcinol plus serotonin resulted in uptake of solutions and silencing of genes expressed in the intestine and esophageal glands.
Table 1 The respective potential peaks for various electroactive biomolecules that are produced or consumed by microbes reported in the literaturea ... Serotonin | Indium tin oxide | +0.67 | 66
Unfortunately, except for the intraventricular injections described by Sherwood,7 there have been, thus far, no documented reports of serotonin-induced mental disturbance* in man that are clearly separable from the natural anxiety initiated by the profound peripheral effects such as circulatory disturbance, other autonomic effects, and emesis. [...] 7. SHERWOOD, S, L. 1955. The responses of psychotic patients to intraventricular injections. Proc. Roy. Soc. Med. 48: 855.
[...] Comparison was made in normal human volunteers of the effects of [...] 5-hydroxytryptamine [...] with [LSD]. The subjects were highly trained to recognize the effects of [LSD] and other hallucinogens. All compounds were given orally. [...] 5-hydroxytryptamine in a dose of 100 mg produced a fall in systolic and a rise in diastolic blood pressures together with a feeling of sedation, abdominal cramping, and muscle aching similar to those of [LSD]. Effects were delayed 6 to 8 hours after dosage. [...]
Table III: Orally and Parenterally Active Psychotropic Tryptamine Derivatives* [...] Name of Compound: Serotonin [...] Dosage (mg): 100#. Route: Oral. [...] # Cardiovascular and autonomic symptoms; little central activity.
Table I. Human Potency of the Hallucinogenic Tryptamines [...] Name: Serotonin. Dosage: 100c. Route: Oral. Reference: Murphree et al., 1960. [...] c Largely cardiovascular and autonomic distress.
Ergonovine is a selective and moderately potent tryptaminergic receptor antagonist in various smooth muscles, being only a partially agonistic or antagonistic at tryptaminergic receptors in the central nervous system. In blood vessels the alkaloid is only weakly antagonistic of dopaminergic receptors and partitally agonistic of α-adrenergic receptors. The most pronounced effect of ergonovine is one of direct stimulation of the uterine smooth musculature, resulting in increased muscular tone and an enhancement of the rate and force of rhythmical contractions. This stimulant effect seems to be most closely associated with agonist or partial agonist effects at 5-HT2 receptors. [...] LSD and related hallucinogens are known to interact with brain 5-HT receptors to produce agonist or partial antagonist effects on serotonin activity.
{{cite journal}}: CS1 maint: DOI inactive as of July 2025 (link)Methylergonovine is a serotonergic receptor agonist in the smooth muscle. It is also a weak antagonist of dopaminergic receptors and partial agonist of α-adrenergic receptors.22 Methylergonovine causes uterine contractions and relaxation at low doses, but causes sustained contractions and increased basal tone at high doses.24 The mechanism of action for uterine contraction is not well defined. Uterine contraction is likely produced by methylergonovine agonist effects on the 5-HT2 receptor found in uterine smooth muscle.22 Alternatively, methylergonovine could cause uterine contraction through direct stimulation of the α-adrenergic receptors in the uterus, which has been postulated to lead to calcium mobilization.25
In addition to promoting psychedelic-induced structural neuroplasticity, the intracellular population of 5-HT2ARs might also contribute to the hallucinogenic effects of psychedelics. When we administered a serotonin-releasing agent to wild type mice, we did not observe a HTR. However, the same drug was able to induce a HTR in mice expressing SERT on cortical neurons of the mPFC—a brain region known to be essential for the HTR (49). Thus, activation of intracellular cortical 5-HT2ARs may play a role in the subjective effects of psychedelics. This hypothesis is further supported by previous work demonstrating that a high dose of the serotonin precursor 5-hydroxytryptophan (5-HTP) induces a HTR in WT mice, which can be blocked by an N-methyltransferase inhibitor that prevents the metabolism of 5-HTP to N-methyltryptamines (50). Inhibition of N-methyltransferase failed to block the HTR induced by 5-MeO-DMT (50). Taken together, this work emphasizes that accessing intracellular 5-HT2ARs is important for 5-HT2AR agonists to produce a HTR.
Octopamine and serotonin regulates the activity of the M3 neurons that direct contraction of the pharynx during C. elegans feeding... Soaking Meloidogyne J2 in dsRNA in the presence of ... resorcinol plus serotonin resulted in uptake of solutions and silencing of genes expressed in the intestine and esophageal glands.
p. 231,
The change in the number of several potential neurotransmitters ... such as serotonin... may play an important role in remodeling the CNS during phase change (26, 56, 80).
p. 233,
In the locust S. gregaria, the amount of serotonin in the thoracic ganglia was positively correlated with the extent of gregarious behavior induced by different periods of crowding. A series of pharmacological and behavioral experiments demonstrated that serotonin plays a key role in inducing initial behavioral gregarization (2, 80). However, serotonin is not responsible for maintaining gregarious behavior because its amount in long-term gregarious locusts is less than half that in long-term solitarious locusts (80). In L. migratoria, the injection of serotonin can also slightly initiate gregarious behavior, but serotonin when accompanying crowding treatment induced more solitarious-like behavior than did serotonin injection alone (48). Significant differences in serotonin levels were not found in brain tissues between the two phases of L. migratoria. A recent report by Tanaka & Nishide (97) measured attraction/avoidance behavior in S. gregaria after single and multiple injections of serotonin at different concentrations. Serotonin had only a short-term effect on the level of some locomotor activities and was not involved in the control of gregarious behavior (97). In addition, it is not clear how the neurotransmitter influences this unique behavior, because a binary logistic regression model used in these studies for the behavioral assay focused mostly on only one behavioral parameter representing an overall phase state. Obviously, behavioral phase change might involve alternative regulatory mechanisms in different locust species. Therefore, these studies demonstrate that CNS regulatory mechanisms governing initiation and maintenance of phase change are species specific and involve the interactions between these neurotransmitters.
Given the key roles of aminergic signaling, what are the downstream pathways involved in the establishment of long-term memory? Ott et al. (63) investigated the role of [] protein kinase[] in the phase change in S. gregaria: ... cAMP-dependent protein kinase A (PKA). Through use of pharmacological and RNAi intervention, these authors have demonstrated that PKA... has a critical role in modulating the propensity of locusts to acquire and express gregarious behavior. ... Unfortunately, although a correlation between serotonin and PKA was hypothesized, direct evidence was not provided.
...gregarization is evoked by... tactile stimulation... Tactile stimuli trigger the increase of biogenic amines, particularly serotonin, in the locust nervous system (1, 116); these amines play critical roles in the neurophysiology of locust behavioral phase change.
Table 1 The respective potential peaks for various electroactive biomolecules that are produced or consumed by microbes reported in the literaturea ... Serotonin | Indium tin oxide | +0.67 | 66
Table III: Orally and Parenterally Active Psychotropic Tryptamine Derivatives* [...] Name of Compound: Serotonin [...] Dosage (mg): 100#. Route: Oral. [...] # Cardiovascular and autonomic symptoms; little central activity.
Table I. Human Potency of the Hallucinogenic Tryptamines [...] Name: Serotonin. Dosage: 100c. Route: Oral. Reference: Murphree et al., 1960. [...] c Largely cardiovascular and autonomic distress.
13.9 Indolealkylamines and the CNS in human beings 13.91 Central effects of 5-HT [...]
{{cite book}}: ISBN / Date incompatibility (help); |journal= ignored (help)Unfortunately, except for the intraventricular injections described by Sherwood,7 there have been, thus far, no documented reports of serotonin-induced mental disturbance* in man that are clearly separable from the natural anxiety initiated by the profound peripheral effects such as circulatory disturbance, other autonomic effects, and emesis. [...] 7. SHERWOOD, S, L. 1955. The responses of psychotic patients to intraventricular injections. Proc. Roy. Soc. Med. 48: 855.
Serotonin. [...] 4 patients received this drug in doses of 15 to 75 μg. [...]
In 1964, Dahlstrom and Fuxe (discussed in [2]), using the Falck-Hillarp technique of histofluorescence, observed that the majority of serotonergic soma are found in cell body groups, which previously had been designated as the Raphe nuclei.
Ergonovine is a selective and moderately potent tryptaminergic receptor antagonist in various smooth muscles, being only a partially agonistic or antagonistic at tryptaminergic receptors in the central nervous system. In blood vessels the alkaloid is only weakly antagonistic of dopaminergic receptors and partitally agonistic of α-adrenergic receptors. The most pronounced effect of ergonovine is one of direct stimulation of the uterine smooth musculature, resulting in increased muscular tone and an enhancement of the rate and force of rhythmical contractions. This stimulant effect seems to be most closely associated with agonist or partial agonist effects at 5-HT2 receptors. [...] LSD and related hallucinogens are known to interact with brain 5-HT receptors to produce agonist or partial antagonist effects on serotonin activity.
{{cite journal}}: CS1 maint: DOI inactive as of July 2025 (link)In addition to promoting psychedelic-induced structural neuroplasticity, the intracellular population of 5-HT2ARs might also contribute to the hallucinogenic effects of psychedelics. When we administered a serotonin-releasing agent to wild type mice, we did not observe a HTR. However, the same drug was able to induce a HTR in mice expressing SERT on cortical neurons of the mPFC—a brain region known to be essential for the HTR (49). Thus, activation of intracellular cortical 5-HT2ARs may play a role in the subjective effects of psychedelics. This hypothesis is further supported by previous work demonstrating that a high dose of the serotonin precursor 5-hydroxytryptophan (5-HTP) induces a HTR in WT mice, which can be blocked by an N-methyltransferase inhibitor that prevents the metabolism of 5-HTP to N-methyltryptamines (50). Inhibition of N-methyltransferase failed to block the HTR induced by 5-MeO-DMT (50). Taken together, this work emphasizes that accessing intracellular 5-HT2ARs is important for 5-HT2AR agonists to produce a HTR.
Serotonin. [...] 4 patients received this drug in doses of 15 to 75 μg. [...]
...gregarization is evoked by... tactile stimulation... Tactile stimuli trigger the increase of biogenic amines, particularly serotonin, in the locust nervous system (1, 116); these amines play critical roles in the neurophysiology of locust behavioral phase change.
Table 1 The respective potential peaks for various electroactive biomolecules that are produced or consumed by microbes reported in the literaturea ... Serotonin | Indium tin oxide | +0.67 | 66
[...] Comparison was made in normal human volunteers of the effects of [...] 5-hydroxytryptamine [...] with [LSD]. The subjects were highly trained to recognize the effects of [LSD] and other hallucinogens. All compounds were given orally. [...] 5-hydroxytryptamine in a dose of 100 mg produced a fall in systolic and a rise in diastolic blood pressures together with a feeling of sedation, abdominal cramping, and muscle aching similar to those of [LSD]. Effects were delayed 6 to 8 hours after dosage. [...]
Two obstacles effectively prohibit this availability. Serotonin has a free hydroxy group (the 5-hydroxy which is the H of 5-HT). This is a big polar water-loving pimple which denies it any passage across the brain's defensive Maginot Line, the blood-brain barrier. And there is the second problem. There is a exposed amino group, the amine of T of 5-HT, the tryptamine, which is immediately removed by the body's monoamine oxidase enzyme. In short, it is blocked from entry into the brain because it is both too polar and too metabolically fragile.