scholarly journals Serotonin Receptors in Hippocampus

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Laura Cristina Berumen ◽  
Angelina Rodríguez ◽  
Ricardo Miledi ◽  
Guadalupe García-Alcocer
Keyword(s):  
Limbic System ◽  
Immune Cells ◽  
Serotonin Receptors ◽  
Serotonin Receptor ◽  
Functional Network ◽  
Receptor Subtypes ◽  
Postsynaptic Receptors ◽  
Molecular Signal ◽  
Almost All

Serotonin is an ancient molecular signal and a recognized neurotransmitter brainwide distributed with particular presence in hippocampus. Almost all serotonin receptor subtypes are expressed in hippocampus, which implicates an intricate modulating system, considering that they can be localized as autosynaptic, presynaptic, and postsynaptic receptors, even colocalized within the same cell and being target of homo- and heterodimerization. Neurons and glia, including immune cells, integrate a functional network that uses several serotonin receptors to regulate their roles in this particular part of the limbic system.

scholarly journals Different Serotonin Receptor Agonists Have Distinct Effects on Sound-Evoked Responses in Inferior Colliculus

2006 ◽  
Vol 96 (5) ◽  
pp. 2177-2188 ◽  
Author(s):  
Laura M. Hurley
Keyword(s):  
Inferior Colliculus ◽  
Auditory Processing ◽  
Serotonin Receptors ◽  
Serotonin Receptor ◽  
Frequency Tuning ◽  
Receptor Subtypes ◽  
Tuning Curves ◽  
Wide Range ◽  
Selective Agonists ◽  
Auditory Nucleus

The neuromodulator serotonin has a complex set of effects on the auditory responses of neurons within the inferior colliculus (IC), a midbrain auditory nucleus that integrates a wide range of inputs from auditory and nonauditory sources. To determine whether activation of different types of serotonin receptors is a source of the variability in serotonergic effects, four selective agonists of serotonin receptors in the serotonin (5-HT) 1 and 5-HT2 families were iontophoretically applied to IC neurons, which were monitored for changes in their responses to auditory stimuli. Different agonists had different effects on neural responses. The 5-HT1A agonist had mixed facilitatory and depressive effects, whereas 5-HT1B and 5-HT2C agonists were both largely facilitatory. Different agonists changed threshold and frequency tuning in ways that reflected their effects on spike count. When pairs of agonists were applied sequentially to the same neurons, selective agonists sometimes affected neurons in ways that were similar to serotonin, but not to other selective agonists tested. Different agonists also differentially affected groups of neurons classified by the shapes of their frequency-tuning curves, with serotonin and the 5-HT1 receptors affecting proportionally more non-V-type neurons relative to the other agonists tested. In all, evidence suggests that the diversity of serotonin receptor subtypes in the IC is likely to account for at least some of the variability of the effects of serotonin and that receptor subtypes fulfill specialized roles in auditory processing.

scholarly journals Regulation of tryptophan 2,3-dioxygenase by HOXA10 enhances embryo viability through serotonin signaling

2011 ◽  
Vol 300 (1) ◽  
pp. E86-E93 ◽  
Author(s):  
Leo F. Doherty ◽  
Hye Eun Kwon ◽  
Hugh S. Taylor
Keyword(s):  
Embryo Development ◽  
Serotonin Receptors ◽  
Serotonin Receptor ◽  
Embryo Implantation ◽  
Constitutive Expression ◽  
Normal Embryo ◽  
Receptor Subtypes ◽  
Embryo Viability ◽  
Endometrial Stroma

Tryptophan 2,3-dioxygenase (TDO) is expressed in endometrium and catabolizes tryptophan, a precursor in the biosynthesis of serotonin. Tryptophan metabolism is an important mechanism for regulation of serotonin levels. Preimplantation mouse embryos are known to express serotonin receptors, specifically the 5-HT1D and 5-HT7 serotonin receptor subtypes. Here we demonstrate that Hoxa10 regulates endometrial TDO expression and improves embryo viability through increased serotonin production. Transfection of pcDNA- Hoxa10 to the murine uterus increased total TDO expression. In vitro, epithelial cell TDO expression was decreased after transfection with Hoxa10. Decreased glandular TDO in response to HOXA10 may augment serotonin production by increasing tryptophan availability. Conversely, stromal TDO expression increased with constitutive Hoxa10 expression. In mice, epithelial serotonin was increased in response to constitutive expression of Hoxa10. Embryo quality was impaired after treatment with Hoxa10 antisense. Blockade of serotonin receptors 1D and 7 also resulted in impaired embryo development, indicating an essential role for Hoxa10 induction of TDO and subsequent serotonin production in embryo development. Transfection of pcDNA- TDO also decreased the number of T cells in the endometrial stroma. We have shown a novel mechanism by which HOXA10 regulates endometrial TDO expression. In the endometrial stroma, HOXA10 increases TDO mRNA, which may increase tryptophan catabolism, allowing for immune tolerance at the time of embryo implantation. In endometrial glands, HOXA10 decreases TDO mRNA leading to increased serotonin that in turn acts to promote normal embryo development.

Is there a Relationship between Serotonin Receptor Subtypes and Selectivity of Response in Specific Psychiatric Illnesses?

1989 ◽  
Vol 155 (S8) ◽  
pp. 63-69 ◽  
Author(s):  
Stuart A. Montgomery ◽  
Naomi Fineberg
Keyword(s):  
Memory Impairment ◽  
Serotonin Receptor ◽  
Receptor Subtypes ◽  
Psychiatric Illnesses ◽  
Subtype Specificity ◽  
Anxiety Treatment ◽  
High Doses ◽  
Almost All ◽  
Anxiety Depression

Identification of 5-HT receptor subtypes — 5-HT1A, 5-HT1B, 5-HT1c, 5-HT1D, 5-HT2 (possibly A and B), 5-HT3 subtypes, and possibly 5-HT4 — has encouraged the manufacture of 5-HT receptor inhibitors with greater subtype specificity. However, it appears that the receptors interact, and drugs initially thought to be specific may have multiple actions. For some conditions such as anxiety/depression, almost all receptors are implicated. Clinical studies provide clear evidence that manipulation of the 5-HT system has a role in treating depression, anxiety, obsessional illness, migraine, and eating disorders. Interactions between the various receptor subtypes make it difficult to identify specific clinical functions. The 5-HT1A receptors may be involved in aggression, anorexia, and hypotension. The 5-HT1B receptors may be involved in aggression, while the 5-HT1C receptors may play a role in central aversion systems and anxiety/depression. The role of the 5-HT1D receptors remains speculative; 5-HT2 receptors appear to be involved in depression, anxiety, appetite, sleep, vasoconstriction, and hypertension. Many drugs that are effective in treating migraine are potent 5-HT2 antagonists. 5-HT3 antagonists at high doses are effective in treating nausea and at low doses in treating anxiety. Treatment of aggression, suicidal behaviour, addiction behaviour, memory impairment, dementia, and schizophrenia with 5-HT inhibitors requires further testing.

scholarly journals Living-Cell Diffracted X-ray Tracking Analysis Confirmed Internal Salt Bridge Is Critical for Ligand-Induced Twisting Motion of Serotonin Receptors

2021 ◽  
Vol 22 (10) ◽  
pp. 5285
Author(s):  
Kazuhiro Mio ◽  
Shoko Fujimura ◽  
Masaki Ishihara ◽  
Masahiro Kuramochi ◽  
Hiroshi Sekiguchi ◽  
...  
Keyword(s):  
Serotonin Receptors ◽  
Serotonin Receptor ◽  
Frame Rate ◽  
Receptor Subtype ◽  
Transmembrane Segment ◽  
Hek 293 ◽  
Gold Nanocrystals ◽  
X Ray ◽  
Time Dynamics ◽  
Analytical Technique

Serotonin receptors play important roles in neuronal excitation, emotion, platelet aggregation, and vasoconstriction. The serotonin receptor subtype 2A (5-HT2AR) is a Gq-coupled GPCR, which activate phospholipase C. Although the structures and functions of 5-HT2ARs have been well studied, little has been known about their real-time dynamics. In this study, we analyzed the intramolecular motion of the 5-HT2AR in living cells using the diffracted X-ray tracking (DXT) technique. The DXT is a very precise single-molecular analytical technique, which tracks diffraction spots from the gold nanocrystals labeled on the protein surface. Trajectory analysis provides insight into protein dynamics. The 5-HT2ARs were transiently expressed in HEK 293 cells, and the gold nanocrystals were attached to the N-terminal introduced FLAG-tag via anti-FLAG antibodies. The motions were recorded with a frame rate of 100 μs per frame. A lifetime filtering technique demonstrated that the unliganded receptors contain high mobility population with clockwise twisting. This rotation was, however, abolished by either a full agonist α-methylserotonin or an inverse agonist ketanserin. Mutation analysis revealed that the “ionic lock” between the DRY motif in the third transmembrane segment and a negatively charged residue of the sixth transmembrane segment is essential for the torsional motion at the N-terminus of the receptor.

scholarly journals The Cross-Talk between Mesenchymal Stem Cells and Immune Cells in Tissue Repair and Regeneration

2021 ◽  
Vol 22 (5) ◽  
pp. 2472
Author(s):  
Carl Randall Harrell ◽  
Valentin Djonov ◽  
Vladislav Volarevic
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Immune Cells ◽  
Tissue Repair ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Multipotent Stem Cells ◽  
Tissue Repair And Regeneration ◽  
Almost All ◽  
And Function

Mesenchymal stem cells (MSCs) are self-renewable, rapidly proliferating, multipotent stem cells which reside in almost all post-natal tissues. MSCs possess potent immunoregulatory properties and, in juxtacrine and paracrine manner, modulate phenotype and function of all immune cells that participate in tissue repair and regeneration. Additionally, MSCs produce various pro-angiogenic factors and promote neo-vascularization in healing tissues, contributing to their enhanced repair and regeneration. In this review article, we summarized current knowledge about molecular mechanisms that regulate the crosstalk between MSCs and immune cells in tissue repair and regeneration.

Serotonin Receptor Subtypes: Implications for Psychopharmacology

1991 ◽  
Vol 159 (S12) ◽  
pp. 7-14 ◽  
Author(s):  
P. J. Cowen
Keyword(s):  
Cognitive Processes ◽  
Serotonin Receptor ◽  
Antidepressant Treatment ◽  
Receptor Subtypes ◽  
Therapeutic Effects ◽  
Controlled Clinical Trials ◽  
Wide Range ◽  
Selective Ligands ◽  
Coupling Mechanisms ◽  
Therapeutic Possibilities

Serotonin (5-HT) interacts with multiple brain 5-HT receptor subtypes to influence a wide range of behaviours. Three main families of 5-HT receptors (5-HT1, 5-HT2 and 5-HT3) have been described which differ in their binding affinity for selective ligands, their receptor-effector coupling mechanisms, and the behavioural processes they regulate. Nevertheless, manipulation of several different 5-HT receptor subtypes (5-HT1A, 5-HT1c, 5-HT2 and 5-HT3) may produce anxiolytic effects; 5-HT1A and 5-HT2 receptors may be involved in the aetiology of major depression and the therapeutic effects of antidepressant treatment; and 5-HT3 receptors have been linked to reward mechanisms and cognitive processes. These advances offer therapeutic possibilities, the value of which can only be satisfactorily assessed by controlled clinical trials.

scholarly journals Role of some types of serotonin receptors in murine hypophyseal-testicular complex activation induced by the presence of a female

2003 ◽  
Vol 49 (6) ◽  
pp. 53-56
Author(s):  
T. G. Amstislavskaya ◽  
N. K. Popova
Keyword(s):  
Serotonin Receptors ◽  
Receptor Agonist ◽  
Serotonin Receptor ◽  
Receptive Female ◽  
Plasma Testosterone ◽  
Blood Levels ◽  
Inhibitory Effects ◽  
Sexual Activation ◽  
Different Types

Placement of a sexually receptive female mouse behind a partition that prevents physical contacts, but permits it to see and smell caused an increase in the blood levels of testosterone in male mice. The selective 5-HTIA-serotonin receptor agonist 08-OH- DPAT (0.1 mg/kg) and the mixed 5-HTIA/IB agonist eltoprazine, 3.0 and 10.0 mg/kg, blocked the activating effect of female exposure on the male pituitary-testicular system. The 5-HT/-receptor agonist p-MPPI (0.2 mg/kg) prevented the inhibitory effects of 8-OH-DPATand eltoprazine. The 5-HT/B-receptor agonist CGS- 12066A (1.0 and 2.0 mg/kg) exerted no effect while the mixed 5-HTIB/2C-receptor agonist TFMPP (5.2 mg/kg) inhibited a female-induced increase in the levels of male blood testosterone. The 5-HT/-receptor agonist keranserin (1.0 and 2.0 mg/kg) prevented a female-induced increase in the levels of testosterone. The 5-HT3-receptor agonist ondansetron (0.05 and 0.1 mg/kg) elevated the baseline level of plasma testosterone, but blocked receptive female-induced activation of the male hypothalamic-pituitary-testicular system (HPTS). It is concluded that 5-HTIA-receptors are involved in the control of male sexual activation. At the same time different types and even subtypes of the same type of 5-HT-receptors produce varying inhibitory and activating effects on the receptive female-induced activation of HPTS. Blocking of the female-induced activation of HPTS seems to be realized by involving 5-HTu- and 5-HT2C-receptors and its activation occurs with the participation of 5-HT^- and 5- HT3-receptors.

Serotonin Receptor Subtypes

1993 ◽  
pp. 15-25 ◽  
Author(s):  
P. R. Hartig ◽  
N. Adham ◽  
J. Zgombick ◽  
M. Macchi ◽  
H.-T. Kao ◽  
...  
Keyword(s):  
Serotonin Receptor ◽  
Receptor Subtypes
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