Search Results (156)

Prader–Willi syndrome (PWS) is a rare imprinting-related neurodevelopmental disorder caused by loss of paternally expressed genes within the chromosome 15q11–q13 region, including SNORD116, MAGEL2, and NDN. It provides a natural model for examining how genomic imprinting disruptions shape neural development and psychiatric vulnerability. This review synthesizes current evidence to clarify the mechanistic pathways linking imprinting defects and epigenetic dysregulation to neuropsychiatric outcomes in PWS. Published studies—including patient-derived induced pluripotent stem cell (iPSC) models, animal knockout systems (e.g., Magel2-null models), transcriptomic and DNA methylation datasets, and human neuroimaging research—were identified through targeted searches of PubMed and Web of Science and integrated narratively rather than through systematic procedures. Across these data sources, deletion-type PWS is primarily associated with impaired neuronal maturation, altered serotonergic signaling, and locus-specific transcriptional dysregulation. Maternal uniparental disomy (mUPD) is characterized by broader epigenetic alterations within the imprinted domain, genome-wide transcriptional effects, dopaminergic pathway alterations, and disrupted prefrontal–limbic connectivity linked to increased psychosis risk. Importantly, available evidence supports substantial phenotypic and mechanistic overlap between PWS subtypes, with genotype–phenotype associations reflecting probabilistic tendencies rather than categorical distinctions. Collectively, convergent findings across molecular, neurochemical, and systems-level studies support a mechanistic continuum extending from imprinting defects to behavioral phenotypes. These insights position PWS as a translational model for understanding how epigenetic dysregulation contributes to psychiatric risk and highlight the need for genotype-informed, mechanistically grounded research to advance biomarker development and targeted therapeutic strategies. Full article

Background/Objectives: Sleep is fundamental to physical and mental health, yet many individuals experience impaired sleep quality. Although pharmacological interventions are available, they are associated with risks of dependency and adverse effects, underscoring the urgent need for safer, food-based alternatives. Blueberry leaves, rich in hyperoside, are suggested to influence sleep through serotonergic and melatonergic pathways; however, while their potential to help maintain sleep quality has been noted, the sleep-enhancing effects of fermented blueberry leaf tea have not yet been demonstrated. This present randomized, double-blind, placebo-controlled trial evaluated the sleep-enhancing effects of fermented blueberry leaf tea on sleep quality. Methods: Fifty adults (aged 20–69 years) reporting poor sleep were randomly assigned to consume either fermented blueberry leaf tea (n = 25) or placebo tea (n = 25) three times daily for two weeks. Objective sleep parameters—sleep efficiency, wake after sleep onset (WASO), sleep latency, and total sleep time—were assessed using actigraphy, while subjective sleep quality was evaluated using the Oguri–Shirakawa–Azumi Sleep Inventory MA (OSA-MA) version questionnaire. Results: In the per-protocol analysis (active: n = 22; placebo: n = 20), the active group exhibited significant improvements in sleep efficiency and WASO compared with the placebo (p < 0.05). No significant differences were observed for sleep latency, total sleep time, or subjective assessments. Importantly, baseline sleep efficiency and WASO were negatively correlated with their respective improvements, suggesting that individuals with poorer initial sleep benefited most. Conclusions: These findings demonstrate that fermented blueberry leaf tea may enhance sleep continuity within two weeks, particularly among individuals with fragmented sleep, and support the potential role of functional foods in sleep health strategies. Trial registration: University Hospital Medical Information Network (UMIN), UMIN000055879; registered on 21 October 2024. Full article

Background: Several studies have attempted to identify the initiating drivers of small intestinal neuroendocrine tumor (SI-NET) development and the molecular mechanisms underlying their progression and metastatic spread. Previous gene expression studies have used bulk microarrays or RNA sequencing to compare tumor tissue with normal intestinal mucosa. However, the intestine comprises multiple distinct cell types, and bulk analyses are limited by this cellular heterogeneity, which can confound tumor-specific signals. Methods: We performed single-cell RNA sequencing on primary SI-NETs and paired normal mucosa from two patients to directly compare tumor cells with their cells of origin, the enterochromaffin (EC) cells. To minimize type I errors, we applied a two-step validation strategy by overlapping differentially expressed genes with an external single-cell dataset and cross-referencing candidate genes for enteroendocrine expression in the Human Protein Atlas. Results: For further distinction and characterization, ECs were subdivided into serotonergic and non-serotonergic clusters. This analysis revealed that the SI-NET cells are transcriptionally more similar to serotonergic ECs, consistent with serum metabolite profiles derived from clinical parameters. Our analyses uncovered a loss-of-expression program characterized by regulators of epithelial differentiation and in parallel, a gain-of-expression program displayed neuronal signaling gene induction, implicating functional reprogramming toward neuronal-like properties. Together, these specific losses and gains suggest that our patient-derived SI-NETs undergo adaptation through both loss of enteroendocrine functions and acquisition of neurobiological-promoting signaling pathways. Conclusions: These findings nominate candidate drivers for further functional validation and highlight potential therapeutic strategies in our patient cohort, including restoring suppressed Notch signaling and targeting aberrant neuronal signaling networks. However, even with a two-step validation procedure, the modest cohort size limits statistical power and generalizability, particularly for the proposed association to a serotonergic phenotype. Larger, multi-patient single-cell studies are required to confirm these mechanisms and establish their clinical relevance. Full article

The objective of this study was to determine if the use of human chorionic gonadotrophin (hCG) and ketoprofen would affect the pregnancy percentages of dairy cows following timed artificial insemination (TAI). This experiment was conducted on a commercial dairy farm in China involving 799 healthy Holstein cows (2–4 parities) between October and December 2024. Cows were randomly assigned to three groups: hCG-3 = treated with (0 d: GnRH, 100 μg; 7–8 d: PGF_2α, 0.4 mg; 52 h: GnRH, 100 μg; 14–16 h: TAI) + hCG 3 vials (300 µg)/cow on day 7 of TAI; hCG-2 group = TAI + 2 vials (200 µg) hCG/cow on day 7; and hCG+ketoprofen = TAI + 300 µg hCG/cow + ketoprofen 10 mL/cow on days 15 and 16 of TAI. Metabolomic profiling (untargeted and targeted) of 22 pregnant cows was conducted on serum collected on days 17 and 21 post-TAI. Results indicated greater pregnancy percentages in the cows of the hCG+ketoprofen-treated group compared to those in the other two groups (60.1% compared with 49.6% and 41.9%). The cows treated with hCG+ketoprofen had less oxidative stress markers, downregulation of arachidonic acid metabolism and upregulation of glycerophospholipid metabolism on day 17 after TAI, indicating that there was upregulation of tryptophan and serotonergic pathways, increased amino acid metabolism and continued anti-inflammatory effects on day 21 after TAI. These findings were confirmed by evaluation data collected by conducting the targeted metabolomic procedures, as indicated by the greater progesterone and melatonin and lesser 17-estradiol and 21-deoxycortisol concentrations. These findings indicate that combined hCG+ketoprofen administrations following the TAI treatment regimen improve pregnancy percentages in dairy cattle as a result of metabolic and endocrine milieu modulations. Full article

Growing evidence has revealed that gut dysbiosis is associated with the development of anxio-depressive disorders through mechanisms that involve neuroimmune signaling, neurotransmitter changes, and neuroplasticity in the brain. This study investigated the effects of gingerol-enriched ginger (GEG) on specifically anxiety-related neuroinflammation-, neuroimmunity-, neuroplasticity-, neurotransmission-, and neurotoxicity-associated genes in different brain regions, as well as on alterations linked to colonic microflora-driven dysbiosis, in the spinal nerve ligation (SNL) rat model of neuropathic pain (NP). Twenty-seven male rats were assigned to 3 groups: sham, SNL, and SNL-treated with GEG at 200 mg/kg body weight (SNL+200GEG) via oral gavage for 5 weeks. Anxiety-like behavior was assessed on the elevated plus maze (EPM). mRNA expression was assessed by qRT-PCR using respective primers. Correlation between behavioral parameters and colonic microbiome composition was analyzed using the Spearman rank correlation. The SNL+200GEG group demonstrated decreased anxiety-like behavior in the SNL model. Compared to the SNL group, the SNL+200GEG group had increased mRNA expression of NRF2 (amygdala: left), LXRα (amygdala: both sides), and CX3CR1 (amygdala: both sides, hippocampus: right). GEG modulated neuroplasticity as shown by increased gene expression of PGK1 (amygdala: right, hippocampus: both sides), MEK1 (frontal cortex: both sides), LDHA (frontal cortex: both sides), GPM6A (frontal cortex: both sides, amygdala: right, hippocampus: right, and hypothalamus), and GLUT1 (amygdala: right) as well by decreased gene expression of HIF1α (in all brain regions except for the hypothalamus). GEG modulated neurotransmission via clearance of excessive glutamate release as suggested by increased gene expression of SLC1A3 (frontal cortex: both sides, hippocampus: right) and via augmenting mGluR5 signaling as shown by increased gene expression of GRM5 (hippocampus: both sides, hypothalamus) as well as downregulation of KMO, HAAO, GRIN2B, and GRIN2C influencing downstream serotonergic neurotransmission and NMDA receptor-mediated glutamatergic pathways in different brain regions. GEG further alleviated neurotoxicity through downregulated gene expression of SIRT1, KMO, IDO1, and HAAO in different brain regions. Moreover, the increased relative abundance of Bilophila spp., accompanied by decreased time spent in the EPM open arms, suggests that increased Bilophila abundance increases anxiety-like behavior. GEG supplementation mitigated anxiety-like behavior in male rats with NP, at least in part, by reducing SNL-induced inflammatory sequelae-related mRNA gene expression in different brain regions. In addition, there is a positive correlation between the abundance of Bilophila wadsworthia and the degree of anxiety-like behavior. Full article

Major depressive disorder remains a leading cause of disability worldwide, with conventional antidepressants offering incomplete and often transient relief. Mounting evidence highlights disturbances in tryptophan (Trp) metabolism as a key biological axis linking inflammation, neuroplasticity, and mood regulation. Plant-derived compounds that modulate this pathway, including 5-hydroxytryptophan, isoflavones, berberine, and polyphenols, have emerged as promising candidates for integrative treatment strategies. Yet, despite encouraging preclinical and clinical findings, knowledge gaps persist regarding long-term efficacy, mechanistic specificity, and standardized therapeutic protocols. This narrative review explores how Trp modulators influence central and peripheral mechanisms relevant to depression, from serotonergic synthesis and kynurenine shunting to gut–brain–immune interactions. Evidence from animal models and randomized clinical trials is critically synthesized, with particular attention to outcomes on mood stabilization, anxiety reduction, cognitive function, and sleep regulation. Special emphasis is placed on translational potential, methodological limitations, and the need for harmonized research frameworks. Here we highlight that phytochemical interventions represent a mechanistically informed and biocompatible strategy for advancing depression management. By bridging neurobiology and clinical psychiatry, these insights may pave the way for next-generation therapeutics that integrate dietary, microbiota-targeted, and anti-inflammatory approaches. Broader application of this research could ultimately refine personalized psychiatry, expand therapeutic horizons, and contribute to global mental health resilience. Full article

Background/Objectives: The therapeutic potential of selective trace amine-associated receptor 1 (TAAR1) agonists has been established in multiple animal models of depression and anxiety. PTSD is a debilitating psychiatric disorder frequently characterized by anxiety and often comorbid with major depressive disorder. Complex PTSD represents an even more severe clinical presentation, emerging from prolonged or repeated exposure to traumatic events. Recent studies indicate that TAAR1 agonists can attenuate anxiety-like behaviors in experimental models of PTSD; however, the molecular mechanisms underlying this effect remain poorly understood. In this study, we evaluated whether TAAR1 agonism modulates PTSD-related neurochemical and molecular changes within the hippocampus and striatum. Methods: Post-traumatic stress was modeled using predator stress, a validated experimental paradigm relevant to complex PTSD. Treatment consisted of intraperitoneal administration of the TAAR1 agonist LK00764. Monoamine neurotransmitters and their metabolites were quantified, and the expression of genes implicated in noradrenergic, dopaminergic, and serotonergic signaling pathways was assessed. In addition, gene network reconstruction was performed using artificial intelligence to identify TAAR1-dependent regulatory interactions. Results: Treatment with a TAAR1 agonist fully prevented behavioral abnormalities in the experimental model of complex PTSD. Neurochemical analyses revealed decreased 5-HT levels in the hippocampus and reduced dopamine and metabolite concentrations in the striatum following TAAR1 agonism. Moreover, TAAR1 activation was associated with increased expression of the neurotrophic factor BDNF in the striatum. Gene network reconstruction identified a distinct molecular hub within the PTSD network, comprising TAAR1-coexpressed genes, their encoded proteins, and interconnected signaling pathways, suggesting a tightly regulated feedback loop. Conclusions: These findings provide novel evidence that TAAR1 agonists exert protective effects against complex PTSD-related behavioral and neurochemical abnormalities. The reconstructed TAAR1-centered gene network offers mechanistic insight into receptor-dependent regulation of monoaminergic signaling and neuroplasticity, supporting further exploration of TAAR1 agonists as promising therapeutic candidates for PTSD. Full article

Background/Objective: Serotonin and dopamine are key neurotransmitters involved in regulating mood, anxiety, and locomotor activity. Specific transporters mediate their reuptake, SERT and DAT, making them targets for drugs such as Fluoxetine and Methylphenidate. Zebrafish (Danio rerio), due to their genetic and neurochemical similarity to humans, serve as a valuable model for studying the behavioral effects of these drugs. This study aimed to compare the behavioral phenotypes induced by SERT and DAT blockers in adult zebrafish using the Novel Tank Diving Test (NTT), thereby generating a swimming profile for drugs acting on these monoamine transporters that can be utilized in drug discovery and behavior. Methods: Adult zebrafish were administered Fluoxetine or Methylphenidate and subjected to the NTT. Behavioral endpoints measured included bottom-dwelling time (anxiety-like behavior), swimming velocity (locomotor activity), and transitions to the upper zone (exploratory behavior). Results: Fluoxetine treatment significantly reduced bottom-dwelling behavior, increased transitions to the upper zone, and decreased erratic swimming, indicating reduced anxiety and enhanced exploration. In contrast, Methylphenidate administration led to prolonged bottom-dwelling and reduced exploration, suggesting increased anxiety-like behavior and decreased exploration. These findings highlight distinct behavioral profiles resulting from selective modulation of serotonergic and dopaminergic pathways. Conclusions: The study demonstrates that SERT and DAT blockades produce divergent behavioral effects in adult zebrafish, with Fluoxetine exhibiting anxiolytic and exploratory-promoting actions. At the same time, Methylphenidate induces anxiety-like and less exploratory behaviors. These results underscore the utility of zebrafish as a valuable translational model for neuropharmacological research and drug discovery, providing insights into the differential impact of serotonergic and dopaminergic modulation on behavior. Full article

Background/Objectives: Baihe Dihuang Tang (BDT), a classical herbal formula from Zhang Zhongjing’s Han Dynasty work Jin Gui Yao Lue, is widely used to treat depressive disorder by nourishing Yin, clearing heat, and tonifying the heart and lungs. However, its pharmacological mechanisms remain unclear. This study aims to explore BDT’s antidepressant effects via MAOA-regulated serotonin (5-HT) metabolism and synaptic plasticity, supported by experimental validation, while using network pharmacology to predict MAOA-targeting active components. Methods: Active components and targets of BDT were screened using TCMSP, TCMID, and other databases, and then a component-target-pathway network was constructed. A chronic restraint stress (CRS)-induced depressive mouse model was established. Behavioral tests, including open field test (OFT), elevated plus maze (EPM), forced swimming test (FST) and tail suspension test (TST), were conducted to evaluate antidepressant effects. ELISA, qRT-PCR, and Western blot were employed to assess hippocampal 5-HT metabolism (MAOA, 5-HT/5-HIAA ratio) neurotrophic signaling (BDNF, TrkB) and synaptic plasticity-related proteins (PSD-95, SYN1). Results: BDT significantly reduced FST/TST immobility time and improved anxiety-like behaviors in OFT/EPM. BDT treatment downregulated MAOA expression, elevated hippocampal 5-HT/5-HIAA ratio, activated BDNF/TrkB pathway, and upregulated PSD-95/SYN1. Network pharmacology confirmed MAOA’s central role, identifying MAOA/serotonergic synapse modulation as BDT’s main mechanism and pinpointing Ferulic acid, Caffeate, Stigmasterol, (−)-nopinene, Eugenol, and cis-Anethol as MAOA-targeting bioactive components. Conclusions: BDT ameliorates depressive-like behaviors. This effect is mechanistically linked to suppression of MAOA-mediated 5-HT catabolism—a key validated target. This suppression elevates hippocampal 5-HT bioavailability, thereby activating BDNF/TrkB signaling and promoting synaptic plasticity. Network pharmacology confirmed MAOA as a primary target and identified specific modulatory bioactive components. Full article

Irritable Bowel Syndrome (IBS) is a prevalent and heterogeneous functional gastrointestinal disorder with a complex and multifactorial pathophysiology. Traditional treatment approaches have focused on symptom relief, often overlooking the underlying biological mechanisms driving the disease. Τhis review summarizes the current evidence linking core pathophysiological pathways of IBS with mechanism- and diet- based therapeutic strategies to guide personalized treatment. Serotonergic signaling, microbial dysbiosis, immune activation, epithelial barrier dysfunction, and bile acid malabsorption interact to shape the diverse phenotypes of IBS, contributing to altered motility, visceral hypersensitivity, and gut-brain axis dysregulation. Increasing evidence supports that targeted dietary and biological interventions including low-FODMAP and Mediterranean low-FODMAP diets, targeted use of probiotics and psychobiotics, and vitamin D supplementation can modulate microbial composition, reduce luminal irritants, support barrier integrity, and attenuate immune system activation. Similarly, pharmacologic therapies including serotonergic receptor modulators, bile acid sequestrants and neuroimmune agents act on specific mechanistic pathways, reflecting a shift from symptom-based to mechanism-driven management. Collectively, these findings highlight that integrating dietary, microbial, neuroimmune, and serotonergic modulation within a unified therapeutic framework can support a more rational and individualized approach to IBS management and long term symptom control. Full article

Background/Objectives: Thermoregulation is essential for survival, with the hypothalamic preoptic area integrating peripheral signals to maintain core body temperature. While fever enhances immune responses, excessive hyperthermia causes cellular damage. Previous work has shown that central glucagon-like peptide-1 (GLP-1) receptor antagonism intensifies lipopolysaccharide (LPS)-induced fever, suggesting a role for GLP-1 signaling in temperature regulation. However, the direct effects of GLP-1 receptor agonists on fever remained unexplored. This study investigated the effects of liraglutide (LIRA), a GLP-1 analog used to treat diabetes and obesity, on temperature regulation and fever in rats, with a focus on sex-dependent mechanisms. Methods: Male and female Wistar rats received lipopolysaccharide (LPS, i.p.) to induce fever, followed by LIRA treatment (0.3 mg/kg, i.p.) one hour later. Body temperature was monitored for up to six hours post-LPS injection. Results: LIRA reduced body temperature in both euthermic and febrile rats of both sexes. LPS increased PGE₂ concentration in both sexes, with males showing a twofold increase compared to females. LIRA treatment reduced PGE₂ levels in LPS-challenged males (62%, p < 0.01) but not in female rats. LPS elevated interleukin (IL)-6 levels in both sexes, while LIRA treatment decreased IL-6 only in females (45%, p < 0.05). In males, LPS reduced hypothalamic serotonin (5-HT) levels, and LIRA further decreased 5-HT in saline-treated animals. In females, LIRA increased 5-HT levels (84%, p < 0.01) in LPS-challenged animals. Additionally, LIRA exhibited sex-specific effects on hypothalamic JNK phosphorylation, increasing activation in LPS-treated males and reducing it in LPS-treated females. Conclusions: LIRA demonstrates antipyretic properties through distinct, sex-specific mechanisms. In males, temperature reduction correlates with decreased hypothalamic PGE₂, whereas in females, antipyretic effects are associated with reduced IL-6, decreased JNK phosphorylation, and increased 5-HT. These findings reveal sexually dimorphic GLP-1R-mediated thermoregulatory pathways during inflammation. However, the causal relationships between these molecular changes and temperature regulation require further investigation, particularly regarding whether observed biochemical alterations represent primary mechanisms or secondary consequences of temperature modulation. Future studies should investigate the functional significance of the apparent contradiction in serotonergic responses between sexes. Full article

Serotonin (5-hydroxytryptamine) is a key neurotransmitter involved in gastrointestinal and central nervous system functions. Given that approximately 90% of serotonin is synthesized in the gut, dietary interventions targeting the gut microbiota have emerged as promising strategies to modulate serotonin homeostasis. Kefir, a fermented milk beverage rich in probiotics and bioactive compounds, has been suggested to influence gut–brain axis signaling, yet its effects in the pediatric period remain insufficiently characterized. This study aimed to investigate the impact of kefir supplementation on serotonin biosynthesis, receptor expression, and metabolic pathways in a pediatric rat model, focusing on molecular markers across brain, jejunum, and serum tissues. Sixteen male Wistar rats (four weeks old) were divided into kefir and control groups. The kefir group received daily oral gavage of kefir (1 mL/100 g) for eight weeks, while controls received saline. Gene and protein expression levels of serotonergic markers (5-HT, TPH1, TPH2, SLC6A4, VMAT2, 5-HTR2B, 5-HTR3A, and 5-HTR4) were analyzed using quantitative PCR, ELISA, and Western blotting. Serotonin turnover was assessed via 5-HIAA levels. Kefir supplementation significantly increased 5-HT and TPH1 expression in both brain and jejunum tissues. In the brain, kefir elevated TPH2 and upregulated 5-HTR3A and 5-HTR2B, while reducing 5-HIAA levels, suggesting decreased serotonin degradation. In the jejunum, 5-HTR4 expression was markedly increased. Serum analyses revealed reduced TPH1/TPH2 expression but elevated 5-HTR4 levels, indicating systemic modulation of serotonergic signaling. Kefir exerts multifaceted effects on the serotonergic system in pediatric rats by enhancing serotonin biosynthesis, modulating receptor expression, and reducing serotonin turnover. These findings highlight kefir as a potential psychobiotic capable of influencing the gut–brain axis during early life, with implications for pediatric neurodevelopment and mental health. Further research, including clinical trials, is warranted to confirm its translational potential. Full article

Background: Agmatine (AG) is an endogenous neurotransmitter discovered in 1910. It acts on imidazoline I1 and I2 receptors, alpha-2 adrenoceptors, N-methyl-D-aspartate receptors (NMDAR), and serotonergic receptors and modulates nitric oxide synthase (NOS) subtypes. It has neuroprotective, anxiolytic, antidepressant, anticonvulsant, and anti-inflammatory properties and is involved in cognitive functions and withdrawal. The cardiovascular effects of AG began to be explored after the hypotensive effect of clonidine, an imidazoline agonist, was demonstrated. The current study aimed to systematize the effects of AG on the cardiovascular system obtained in previous preclinical studies. Methods: We searched three databases, PubMed, Cochrane, and Embase, using the keywords “agmatine” and “cardiac” or “vascular.” Results: Sixty studies were eligible and included in the analysis. Initially identified as Clonidine Displacing Substance (CDS), AG has demonstrated dual effects—an increase or decrease in blood pressure or in heart rate. Conclusions: The effects exerted by AG depend on the dose and route of administration, as well as on the receptors involved and the pathophysiological pathway used. Full article

The vascular 5-HT sympatho-modulation may involve inhibitory or potentiating pathways: nitric oxide (NO), endothelium-dependent hyperpolarization (EDH)-K⁺ channels, prostanoids, angiotensin II (Ang-II), or endothelin. Compared to males, female rats show differences in the serotonergic sympatho-regulation; therefore, we aimed to study the involvement of indirect pathways via 5-HT_1D-mediated inhibition and 5-HT_2A/3-mediated potentiation of vascular noradrenergic neurotransmission in females. An i.v. bolus of different inhibitors/blockers of modulators/mediators (NO, K⁺ channels, prostanoids, Ang-II, or endothelin) was administered prior to the infusion of the agonists, L-694,247 (5-HT_1D), TCB-2 (5-HT_2A), or 1-PBG (5-HT₃), in female pithed rats. In these conditions, the vascular sympathetic outflow was electrically stimulated to assess the vasopressor responses. The L-694,247 vascular sympatho-inhibition was abolished by a non-selective K⁺ channel blocker, tetraethylammonium. The 1-PBG sympatho-excitatory vascular effect was not modified by any of the inhibitors tested, whereas TCB-2 sympatho-potentiation was blocked solely by losartan (Ang-II type 1 receptor antagonist). Moreover, Ang-II levels were increased after TCB-2 infusion in females. The EDH pathway mediates the 5-HT_1D-induced sympatho-inhibition, while the 5-HT_2A-evoked sympatho-excitatory effect is associated with Ang-II. In contrast, the 5-HT₃ sympatho-potentiation does not involve any indirect pathway. These findings advance current understanding of the complex interactions between 5-HT and vascular homeostasis in female rats. Full article

Serotonin (5-hydroxytryptamine—5-HT) is an important neurotransmitter that exerts a remarkably large array of biological roles in the central nervous system and at the body level. It is involved in generating emotions, being a natural mood stabilizer; it reduces depression, anxiety, modulates sleep, and has many other effects. It is also involved in fetal and postnatal brain development. This variety of biological effects, particularly in the central nervous system, with influence on behavior and cognitive functions, relies on a large number of pre- and postsynaptic serotonin receptor (5-HTR) isoforms spread throughout the brain. They can be grouped in seven large families and include over 18 subtypes, identified based on gene sequences, expression patterns, and pharmacological responses. While in vertebrates these receptors have been properly characterized and described, their correspondents in invertebrates have been far less explored, despite the assumption that they may have similar properties to those described in vertebrates. This paper summarizes the current knowledge in several important areas that together define the entire scope of serotonin receptor research, with a particular emphasis on the role of serotonergic central pathways and circuitry in thermoregulation and correlations with neurologic and psychiatric pathology. Full article