Time of day does not impact spinal serotonin levels in humans.

Spinal serotonin enables neuro-motor recovery (i.e., plasticity) in patients with debilitating paralysis. While there exists time of day fluctuations in serotonin-dependent spinal plasticity, it is unknown, in humans, whether this is due to dynamic changes in spinal serotonin levels or downstream signaling processes. The primary objective of this study was to determine if time of day variations in spinal serotonin levels exists in humans. To assess this, intrathecal drains were placed in seven adults with cerebrospinal fluid (CSF) collected at diurnal (05:00 to 07:00) and nocturnal (17:00 to 19:00) intervals. High performance liquid chromatography with mass spectrometry was used to quantify CSF serotonin levels with comparisons being made using univariate analysis. From the 7 adult patients, 21 distinct CSF samples were collected: 9 during the diurnal interval and 12 during nocturnal. Diurnal CSF samples demonstrated an average serotonin level of 216.6 ± $ \pm $ 67.7 nM. Nocturnal CSF samples demonstrated an average serotonin level of 206.7 ± $ \pm $ 75.8 nM. There was no significant difference between diurnal and nocturnal CSF serotonin levels (p = .762). Within this small cohort of spine healthy adults, there were no differences in diurnal versus nocturnal spinal serotonin levels. These observations exclude spinal serotonin levels as the etiology for time of day fluctuations in serotonin-dependent spinal plasticity expression.

Prescribing patterns in patients with obsessive-compulsive disorder: Retrospective, single-center study.

INTRODUCTION: Obsessive-compulsive disorder (OCD) is marked by a high rate of treatment resistance. Patients are often left trialing medications within multiple drug classes with little response, causing heterogeneity to emerge in prescribing patterns. This analysis seeks to investigate the selection and dosing of the pharmacotherapy utilized, to portray an overview of prescribing trends in the United States. METHODS: This retrospective, single center, review of electronic medical records investigated the pharmacotherapy utilization of patients with a primary diagnosis of OCD. Two hundred and ninety-five patients who received OCD treatment at an urban, academic medical center were included in the study. Patients were included in the review if they were at least eighteen years of age and were assigned a diagnosis of OCD according to DSM-5 criteria. RESULTS: Psychotropic pharmacotherapy was integrated into the care of 93% of patients. Selective serotonin reuptake inhibitors were the most utilized medication class at 85% followed by benzodiazepines (47%) and second-generation antipsychotics (37%). Tricyclic antidepressants and first-generation antipsychotics were the two medication classes utilized the least at 13% and 2% respectively. Additionally, mood stabilizers and serotonin-norepinephrine reuptake inhibitors were utilized at rates of 8% and 16%, respectively. CONCLUSIONS: Evidence-based treatment guidelines are being followed with varying augmentation strategies widely prevalent, thus displaying the heterogeneity in treating OCD. A high rate of benzodiazepine utilization highlights a practice trend with potential ties to clinical factors, such as the latency to treatment effect of other first-line pharmacotherapies. Future prospective studies are required to determine the cultural, pharmacoeconomic and pharmacogenomic factors that contribute to the variation in prescribing practices and whether these variations influence treatment outcomes.

Biosynthetic Pathways of Tryptophan Metabolites in Saccharomyces cerevisiae Strain: Insights and Implications.

Tryptophan metabolites, such as 5-hydroxytryptophan (5-HTP), serotonin, and melatonin, hold significant promise as supplements for managing various mood-related disorders, including depression and insomnia. However, their chemical production via chemical synthesis and phytochemical extraction presents drawbacks, such as the generation of toxic byproducts and low yields. In this study, we explore an alternative approach utilizing S. cerevisiae STG S101 for biosynthesis. Through a series of eleven experiments employing different combinations of tryptophan supplementation, Tween 20, and HEPES buffer, we investigated the production of these indolamines. The tryptophan metabolites were analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Notably, setups replacing peptone in the YPD media with tryptophan (Run 3) and incorporating tryptophan along with 25 mM HEPES buffer (Run 4) demonstrated successful biosynthesis of 5-HTP and serotonin. The highest 5-HTP and serotonin concentrations were 58.9 ± 16.0 mg L-1 and 0.0650 ± 0.00211 mg L-1, respectively. Melatonin concentrations were undetected in all the setups. These findings underscore the potential of using probiotic yeast strains as a safer and conceivably more cost-effective alternative for indolamine synthesis. The utilization of probiotic strains presents a promising avenue, potentially offering scalability, sustainability, reduced environmental impact, and feasibility for large-scale production.

Reviving Bistable Perception in Patients With Depression by Decreasing the Overestimation of Prior Precision.

Slower perceptual alternations, a notable perceptual effect observed in psychiatric disorders, can be alleviated by antidepressant therapies that affect serotonin levels in the brain. While these phenomena have been well documented, the underlying neurocognitive mechanisms remain to be elucidated. Our study bridges this gap by employing a computational cognitive approach within a Bayesian predictive coding framework to explore these mechanisms in depression. We fitted a prediction error (PE) model to behavioral data from a binocular rivalry task, uncovering that significantly higher initial prior precision and lower PE led to a slower switch rate in patients with depression. Furthermore, serotonin-targeting antidepressant treatments significantly decreased the prior precision and increased PE, both of which were predictive of improvements in the perceptual alternation rate of depression patients. These findings indicated that the substantially slower perception switch rate in patients with depression was caused by the greater reliance on top-down priors and that serotonin treatment's efficacy was in its recalibration of these priors and enhancement of PE. Our study not only elucidates the cognitive underpinnings of depression, but also suggests computational modeling as a potent tool for integrating cognitive science with clinical psychology, advancing our understanding and treatment of cognitive impairments in depression.

Effect of l-arginine compared to placebo on sexual function in women with major depressive disorder: a randomized controlled trial.

BACKGROUND: While some evidence suggests that l-arginine may improve sexual function and alleviate depression, it has not been investigated in women with depression to assess both its effects on the depression and sexual function concurrently. METHODS: Patients who had received a diagnosis of major depressive disorder, as determined by predetermined inclusion and exclusion criteria, were enrolled in this triple-blind clinical trial. Patients were divided into two groups: group A, received L-arginine 1 gram twice daily, and group B, received a placebo for four weeks. They were evaluated at baseline, after four and eight weeks with the Hamilton Depression Rating Scale (HDRS), and Rosen's questionnaire or Female Sexual Function Index (FSFI). RESULTS: A decrease in the severity of depression was observed in all patients, which was determined due to Hamilton's questionnaire (P-value < 0.001). During the time in group A, FSFI increased. Based on the FSFI questionnaire, they had improvement in some domains, including the lubrication index and orgasm index, which significantly changed in the eighth week compared to the baseline (P-value < 0.05). However, these two indicators did not change statistically significantly compared to the placebo group. CONCLUSION: L-arginine supplementation can improve sexual function, particularly lubrication and orgasm, and mood in women with depression, with minimal side effects observed. Additional research is necessary to validate these results by examining the effects of higher dosages, extended durations, and larger populations of depressed patients. TRIAL REGISTRATION: Iranian Registry of Clinical Trial: IRCT20100127003210N26.

The utility of PET imaging in depression.

This educational review article aims to discuss growing evidence from PET studies in the diagnosis and treatment of depression. PET has been used in depression to explore the neurotransmitters involved, the alterations in neuroreceptors, non-neuroreceptor targets (e.g., microglia and astrocytes), the severity and duration of the disease, the pharmacodynamics of various antidepressants, and neurobiological mechanisms of non-pharmacological therapies like psychotherapy, electroconvulsive therapy, and deep brain stimulation therapy, by showing changes in brain metabolism and receptor and non-receptor targets. Studies have revealed alterations in neurotransmitter systems such as serotonin, dopamine, GABA, and glutamate, which are linked to the pathophysiology of depression. Overall, PET imaging has furthered the neurobiological understanding of depression. Despite these advancements, PET findings have not yet led to significant changes in evidence-based practices. Addressing the reasons behind inconsistencies in PET imaging results, conducting large sample size studies with a more standardized methodological approach, and investigating further the genetic and neurobiological aspects of depression may better leverage PET imaging in future studies.

Novel 5-HT7 receptor antagonists modulate intestinal immune responses and reduce severity of colitis.

Inflammatory bowel disease (IBD) encompasses a number of debilitating chronic gastrointestinal (GI) inflammatory disorders, including Crohn's disease and ulcerative colitis. In both conditions, mucosal inflammation is a key clinical presentation and is associated with altered serotonin (5-hydroxytryptamine; 5-HT) signaling. This altered 5-HT signaling is also found across various animal models of colitis. Of the 14 known receptor subtypes, 5-HT receptor type 7 (5-HT7) is one of the most recently discovered. We previously reported that blocking 5-HT signaling, with either a selective 5-HT7 receptor antagonist (SB-269970) or genetic ablation alleviated intestinal inflammation in murine experimental models of colitis. Here, we developed novel antagonists, namely MC-170073 and MC-230078, which target 5-HT7 receptors with high selectivity. We also investigated the in vivo efficacy of these antagonists in experimental colitis by utilizing dextran sulfate sodium (DSS) and the transfer of CD4+CD45RBhigh T cells to induce intestinal inflammation. Inhibition of 5-HT7 receptor signaling with the antagonists, MC-170073 and MC-230078, ameliorated intestinal inflammation in both acute and chronic colitis models, which was accompanied by lower histopathological damage and diminished levels of pro-inflammatory cytokines in comparison to vehicle-treated controls. Together, the data reveal that the pharmacological inhibition of 5-HT7 receptors by these selective antagonists ameliorates the severity of colitis across various experimental models and may, in the future, serve as a potential treatment option for patients with IBD. In addition, these findings support that 5-HT7 is a viable therapeutic target for IBD.

Neuroimmune modulation by tryptophan derivatives in neurological and inflammatory disorders.

The nervous and immune systems are highly developed, and each performs specialized physiological functions. However, they work together, and their dysfunction is associated with various diseases. Specialized molecules, such as neurotransmitters, cytokines, and more general metabolites, are essential for the appropriate regulation of both systems. Tryptophan, an essential amino acid, is converted into functional molecules such as serotonin and kynurenine, both of which play important roles in the nervous and immune systems. The role of kynurenine metabolites in neurodegenerative and psychiatric diseases has recently received particular attention. Recently, we found that hyperactivity of the kynurenine pathway is a critical risk factor for septic shock. In this review, we first outline neuroimmune interactions and tryptophan derivatives and then summarized the changes in tryptophan metabolism in neurological disorders. Finally, we discuss the potential of tryptophan derivatives as therapeutic targets for neuroimmune disorders.

Amperometry approach curve profiling to understand the regulatory mechanisms governing the concentration of intestinal extracellular serotonin.

Enterochromaffin (EC) cells located within the intestinal mucosal epithelium release serotonin (5-HT) to regulate motility tones, barrier function and the immune system. Electroanalytical methodologies have been able to monitor steady state basal extracellular 5-HT levels but are unable to provide insight into how these levels are influenced by key regulatory processes such as release and uptake. We established a new measurement approach, amperometry approach curve profiling, which monitors the extracellular 5-HT level at different electrode-tissue (E-T) distances. Analysis of the current profile can provide information on contributions of regulatory components on the observed extracellular 5-HT level. Measurements were conducted from ex vivo murine ileum and colon using a boron-doped diamond (BDD) microelectrode. Amperometry approach curve profiling coupled with classical pharmacology demonstrated that extracellular 5-HT levels were significantly lower in the colon when compared to the ileum. This difference was due to a greater degree of activity of the 5-HT transporter (SERT) and a reduced amount of 5-HT released from colonic EC cells. The presence of an inhibitory 5-HT4 autoreceptor was observed in the colon, where a 40% increase in extracellular 5-HT was the half maximal inhibitory concentration for activation of the autoreceptor. This novel electroanalytical approach allows estimates of release and re-uptake and their contribution to 5-HT extracellular concentration from intestinal tissue be obtained from a single series of measurements.

The effect of spexin injection and its interaction with nitric oxide, serotonin, and corticotropin receptors on the central regulation of food intake in broilers.

Complex homeostatic control mechanisms are tools to adjust the food birds eat and their appetite. Birds and mammals differ in several ways considering food intake regulation. Therefore, this study aimed to investigate the special effects of the intracerebroventricular (ICV) injection of spexin and its interaction with nitric oxide, serotonin and corticotropin receptors on central food intake regulation in broilers. In the test 1, Broilers received ICV injection of saline, PCPA (p-chlorophenylalanine,1.25 µg), spexin (10 nmol) and PCPA+spexin. In test 2-7, 8-OH-DPAT, SB-242084 (5-HT2C, 1.5 µg), L-arginine (Precursor of nitric oxide, 200 nmol), L-NAME (nitric oxide synthetize inhibitor, 100 nmol), Astressin-B (30 µg) and Astressin2-B (30 µg) were injected to Broilers instead of the PCPA. Then, the amount of food received was measured up to 2 h after the injection. The food consumption was significantly decreased by Spexin (10 nmol) (P<0.05). Concomitant injection of SB-242084+spexin attenuated spexin-induced hypophagia (P<0.05). Co-injection of L-arginine+spexin enhanced spexin-induced hypophagia and this effect was reversed by L-NAME (P<0.05). Also, concomitant injection of Astressin-B + spexin or Astressin2-B + spexin enhanced spexin-induced hypophagia (P<0.05). Founded on these observations, spexin-induced hypophagia may be mediated by nitric oxide and 5-HT2C, CRF1, and CRF2 receptors in neonatal broilers.

Concomitant treatment with safinamide and antidepressant drugs: Safety data from real clinical practice / Tratamiento concomitante de safinamida y antidepresivos: Datos de seguridad sobre la práctica en la vida real

Background and purpose: The aim of this study was to assess the possible pharmacological interactions between safinamide and antidepressants, and in particular the appearance of serotonin syndrome with data from real life. Methods: We conducted a retrospective observational study of patients with Parkinson's disease from our Movement Disorders Unit, who were under treatment with any antidepressant drug and safinamide. Specifically, symptoms suggestive of serotonin syndrome were screened for. Also, we collected time of simultaneous use, doses of levodopa and other antiparkinsonian drugs. Results: Clinical records were reviewed for the study period of September 2018 to September 2019. Seventy-eight PD patients who were treated with safinamide of which 25 (32.05%) had a concomitant treatment with an antidepressant drug, being sertraline and escitalopram the most frequent. Mean age was 80 years ± 8.43 and H&Y stage was 3 [2–4]. Mean dose of levodopa used was 703.75 mg ± 233.15. Median duration of concomitant treatment with safinamide and antidepressant drug was 6 months (IQR 20.5), and over eighteen months in 5 cases. No case of serotonin syndrome was recorded, neither was any of its typical manifestations combined or in isolation. Conclusions: Our real clinical practice study suggests that concomitant use of safinamide with antidepressant drugs in PD patients seemed to be safe and well tolerated, even in the long term. However, caution is warranted, individualizing treatment regimens and monitoring the potential appearance of adverse effects.(AU)

Objetivos: El objetivo de este estudio ha sido evaluar las posibles interacciones farmacológicas entre safinamida y antidepresivos; en particular la aparición del síndrome serotoninérgico mediante datos obtenidos en la vida real. Material y métodos: Realizamos un estudio observacional retrospectivo de pacientes con enfermedad de Parkinson (EP) de nuestra unidad de trastornos del movimiento, que estaban en tratamiento con algún fármaco antidepresivo y safinamida. Específicamente, se examinaron los síntomas sugestivos de síndrome serotoninérgico. Además, se recogieron tiempos de uso simultáneo, dosis de levodopa y otros fármacos antiparkinsonianos concomitantes. Resultados: Se revisaron las historias clínicas correspondientes al período de estudio de septiembre de 2018 a septiembre de 2019. Setenta y ocho pacientes con EP se encontraban en tratamiento con safinamida, de los cuales 25 (32,05%) se encontraban recibiendo además un fármaco antidepresivo, siendo sertralina y escitalopram los más frecuentes. La edad media fue de 80 años ± 8,43 y el estadio H&Y fue de 3 [2-4]. La dosis media de levodopa utilizada fue de 703,75 mg ± 233,15. La mediana de duración del tratamiento concomitante con safinamida y un fármaco antidepresivo fue de 6 meses (IQR: 20,5), y más de 18 meses en 5 casos. No se registró ningún caso de síndrome serotoninérgico, ni tampoco ninguno de sus síntomas de forma aislada. Conclusión: Nuestro estudio de práctica clínica real sugiere que el uso concomitante de safinamida con fármacos antidepresivos en pacientes con EP parece ser seguro y bien tolerado, incluso a largo plazo. Sin embargo, es necesaria precaución, individualizando los regímenes de tratamiento, y controlando la posible aparición de efectos adversos.(AU)

The chronic use of serotonin norepinephrine reuptake inhibitors facilitates dyskinesia priming in early Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) patients are frequently exposed to antidepressant medications (ADMs). Norepinephrine (NE) and serotonin (5HT) systems have a role in levodopa-induced dyskinesias (LID) pathophysiology. METHODS: We performed a longitudinal analysis on the PPMI cohort including drug-naïve PD patients, who are progressively exposed to dopamine replacement therapies (DRTs) to test the effect of ADM exposure on LID development by the 4th year of follow-up. RESULTS: LID prevalence (according to MDS UPDRS score 4.1 ≥ 1) was 16% (42/251); these patients were more likely women (p = 0.01), had higher motor (p < 0.001) and depression scores (p = 0.01) and lower putaminal DAT binding ratio (p = 0.01). LID were associated with the exposure time to L-DOPA (2.2 ± 1.07 vs 2.6 ± 0.9, p = 0.02) and to the exposure to ADMs, in particular to SNRI (4.8% vs 21.4%, p < 0.001). The latter persisted after correcting for significant covariates (e.g., disease duration, cognitive status, motor impairment, depression, dopaminergic denervation). A similar difference in LID prevalence in PD patients exposed vs non-exposed to SNRI was observed on matched data by the real-world TriNetX repository (22% vs 13%, p < 0.001). DISCUSSION: This study supports the presence of an effect of SNRI on LID priming in patients with early PD. Independent prospective cohort studies are warranted to further verify such association.

Simultaneous Dopamine and Serotonin Monitoring in Freely Moving Crayfish Using a Wireless Electrochemical Sensing System.

Dopamine (DA) and serotonin (5-HT) are neurotransmitters that regulate a wide range of physiological and behavioral processes. Monitoring of both neurotransmitters with real-time analysis offers important insight into the mechanisms that shape animal behavior. However, bioelectronic tools to simultaneously monitor DA and 5-HT interactive dynamics in freely moving animals are underdeveloped. This is mainly due to the limited sensor sensitivity with miniaturized electronics. Here, we present a semi-implantable electrochemical device achieved by integrating a multi-surface-modified carbon fiber microelectrode with a miniaturized potentiostat module to detect DA and 5-HT in vivo with high sensitivity and selectivity. Specifically, carbon fiber microelectrodes were modified through electrochemical treatment and surface coatings to improve sensitivity, selectivity, and antifouling properties. A customized, lightweight potentiostat module was developed for untethered electrochemical measurements. Integrated with the microelectrode, the microsystem is compact (2.8 × 2.3 × 2.1 cm) to minimize its impacts on animal behavior and achieved simultaneous detection of DA and 5-HT with sensitivities of 48.4 and 133.0 nA/µM, respectively, within submicromolar ranges. The system was attached to the crayfish dorsal carapace, allowing electrode implantation into the heart of a crayfish to monitor DA and 5-HT dynamics, followed by drug injections. The semi-implantable biosensor system displayed a significant increase in oxidation peak currents after DA and 5-HT injections. The device successfully demonstrated the application for in vivo simultaneous monitoring of DA and 5-HT in the hemolymph (i.e., blood) of freely behaving crayfish underwater, yielding a valuable experimental tool to expand our understanding of the comodulation of DA and 5-HT.

Motor evoked potentials in the human upper and lower limb do not increase after single 30-minute sessions of acute intermittent hypoxia.

Acute Intermittent Hypoxia (AIH) can induce sustained facilitation of motor output in people with spinal cord injury (SCI). Most studies of corticospinal tract excitability in humans have used 9% FiO2 AIH (AIH-9%), with inconsistent outcomes. We investigated the effect of single sessions of 9% FiO2 and 12% FiO2 AIH (AIH-12%) on corticospinal excitability of a hand and leg muscle in able-bodied adults. Ten naïve participants without SCI completed three sessions comprising 15 cycles of one minute of AIH-9%, AIH-12% or sham (SHAM-21%) followed by one minute of room air (21% FiO2) in a randomised crossover design. Motor evoked potentials (MEPs, n=30, ~1mV) elicited at rest by transcranial magnetic stimulation and maximal M-waves (Mmax) evoked by peripheral nerve stimulation were measured from the first dorsal interosseous (FDI) and tibialis anterior (TA) muscles at baseline and at ~0, 20, 40, and 60 minutes post-intervention. AIH-9% induced the greatest reduction in SpO2 (to 85% vs 93% and 100% in AIH-12% and SHAM-21%, respectively; p < 0.001) and the greatest increase in ventilation (by 22% vs 12% and -3% in AIH-12% and SHAM-21%, respectively (p<0.001)). There was no difference in MEP amplitudes (%Mmax) after any of the three conditions (AIH-9%, AIH-12%, SHAM-21%) for both FDI (p=0.399) and TA (p=0.582). Despite greater cardiorespiratory changes during AIH-9%, there was no evidence of corticospinal facilitation (tested with MEPs) in this study. Further studies could explore variability in response to AIH between individuals and other methods to measure motor facilitation in people with and without spinal cord injuries.

Antidepressant nonadherence and sexual dysfunction among young adult males: the cross-sectional YAMAN study.

PURPOSE: Selective serotonin reuptake inhibitors are associated with high rates of nonadherence and sexual dysfunction, yet the correlation between these findings in young adult men is poorly characterized. We aimed to evaluate if young adult men are less willing to adhere to antidepressant treatment due to intolerable side effects, such as sexual dysfunction. METHODS: Deidentified, compensated survey that assessed baseline demographics, PHQ-8 and GAD-7 scores, attitudes towards antidepressant medication side effects, and perceptions of antidepressant medications including selective serotonin reuptake inhibitors, bupropion, and mirtazapine. RESULTS: From 665 delivered surveys, 505 respondents completed their survey (response rate: 76%), of which 486 were included for final analysis. After seeing common side effect profiles, our sample's willingness to take sexual function-sparing agents, such as bupropion or mirtazapine, was significantly greater than selective serotonin reuptake inhibitors (p < 0.001), with no significant difference between bupropion and mirtazapine (p = 0.263). The negative influence of erectile dysfunction and anorgasmia scored significantly higher than other common antidepressant side effects like weight gain, nausea, and dry mouth (range: p < 0.001, p = 0.043). With the exception of insomnia, participants indicated that experiencing sexual dysfunction while taking an antidepressant medication would lead to nonadherence at a significantly higher frequency than any other side effect assessed (range: p < 0.001, p = 0.005). CONCLUSION: The risk of experiencing sexual side effects when taking antidepressants could lead young adult men to become nonadherent to these medications. Strategies to augment the effectiveness of antidepressants, such as shared decision-making and the use of sexual function-sparing agents, are critical.

Duloxetine protected indomethacin-induced gastric mucosal injury by increasing serotonin-dependent RANTES expression and activating PI3K-AKT-VEGF pathway.

Antidepressant duloxetine has been shown protective effect on indomethacin-induced gastric ulcer, which was escorted by inflammation in the gastric mucosa. Cytokines are the principal mediators of inflammation. Thus, by screening the differential expression of cytokines in the gastric mucosa using cytokine array at 3 h after indomethacin exposure, when the gastric ulcer began to format, we found that indomethacin increased cytokines which promoted inflammation responses, whereas duloxetine decreased pro-inflammatory cytokines increased by indomethacin and increased RANTES expression. RANTES was consistently increased by pretreated with both 5 mg/kg and 20 mg/kg duloxetine at 3 h and 6 h after indomethacin exposure in male rats. Selective blockade of RANTES-CCR5 axis by a functional antagonist Met-RANTES or a CCR5 antagonist maraviroc suppressed the protection of duloxetine. Considering the pharmacologic action of duloxetine on reuptake of monoamine neurotransmitters, we examined the serotonin (5-HT), norepinephrine and dopamine contents in the blood and discovered 20 mg/kg duloxetine increased 5-HT levels in platelet-poor plasma, while treatment with 5-HT promoted expression of RANTES in the gastric mucosa and alleviated the indomethacin-induced gastric injury. Furthermore, duloxetine activated PI3K-AKT-VEGF signaling pathway, which was regulated by RANTES-CCR5, and selective inhibitor of VEGF receptor axitinib blocked the prophylactic effect of duloxetine. Furthermore, duloxetine also protected gastric mucosa from indomethacin in female rats, and RANTES was increased by duloxetine after 6 h after indomethacin exposure too. Together, our results identified the role of cytokines, particularly RANTES, and the underlying mechanisms in gastroprotective effect of duloxetine against indomethacin, which advanced our understanding in inflammatory modulation by monoamine-based antidepressants.

Neuroprotective Role of Selenium Nanoparticles Against Behavioral, Neurobiochemical and Histological Alterations in Rats Subjected to Chronic Restraint Stress.

Chronic stress induces changes in the prefrontal cortex and hippocampus. Selenium nanoparticles (SeNPs) showed promising results in several neurological animal models. The implementation of SeNPs in chronic restraint stress (CRS) remains to be elucidated. This study was done to determine the possible protective effects of selenium nanoparticles on behavioral changes and brain oxidative stress markers in a rat model of CRS. 50 rats were divided into three groups; control group (n = 10), untreated CRS group (n = 10) and CRS-SeNPs treated group (n = 30). Restraint stress was performed 6 h./day for 21 days. Rats of CRS-SeNPs treated group received 1, 2.5 or 5 mg/kg SeNPs (10 rats each) by oral gavage for 21 days. Rats were subjected to behavioral assessments and then sacrificed for biochemical and histological analysis of the prefrontal cortex and hippocampus. Prefrontal cortical and hippocampal serotonin levels, oxidative stress markers including malondialdehyde (MDA), reduced glutathione (GSH) and glutathione peroxidase (GPx), tumor necrosis factor alpha (TNF-α) and caspase-3 were assessed. Accordingly, different doses of SeNPs showed variable effectiveness in ameliorating disease parameters, with 2.5 mg/kg dose of SeNPs showing the best improving results in all studied parameters. The present study exhibited the neuroprotective role of SeNPs in rats subjected to CRS and proposed their antioxidant, anti-inflammatory and anti-apoptotic effects as the possible mechanism for increased prefrontal cortical and hippocampal serotonin level, ameliorated anxiety-like and depressive-like behaviors and improved prefrontal cortical and hippocampal histological architecture.

Psilocybin reduces alcohol self-administration via selective left nucleus accumbens activation in rats.

The use of psilocybin to treat alcohol use disorder is very promising, but the mechanisms of action remain poorly understood. We combined behavioral, pharmacological and gene expression analyses to decipher the mechanisms of action of psilocybin, for the first time injected into the brain. Male Long Evans rats underwent chronic operant ethanol self-administration before testing the effect of intraperitoneal psilocybin or directly within the nucleus accumbens core or the ventral tegmental area. Transcripts from the dopaminergic system were quantified in the nucleus accumbens and prefrontal cortex. Psilocybin significantly reduced (50%) ethanol self-administration when injected 4 hours before the session either intraperitoneally (1mg/kg) or directly within the left nucleus accumbens (0.15µg) but not the right nucleus accumbens or the left ventral tegmental area. The effect of intraperitoneal injection of psilocybin was prevented by intra left nucleus accumbens injection of 0.3µg of the 5-HT2AR antagonist ketanserin. In rats that self-administered ethanol but not in those self-administering saccharin, dopamine D2 receptor mRNA were increased in both the nucleus accumbens and the prefrontal cortex by psilocybin, while D1R mRNA was increased only in the prefrontal cortex. As in humans, psilocybin reduced ethanol self-administration in rats through the 5-HT2AR within the left nucleus accumbens possibly through increased D2R expression. Our results open unexpected perspectives regarding the hemispheric lateralization of psychedelic effects.

Off-label higher doses of serotonin reuptake inhibitors in the treatment of obsessive-compulsive disorder: Safety and tolerability.

OBJECTIVE: To examine the long-term safety and tolerability of off-label high-dose serotonin reuptake inhibitors (OLHD-SRIs) in the treatment of obsessive-compulsive disorder (OCD). METHODS: A retrospective longitudinal study was performed on 105 randomly selected outpatients diagnosed with OCD and were treated with OLHD-SRIs for at least 6 months. Patients received sertraline >200 mg/day, escitalopram >20 mg/day, fluvoxamine >300 mg/day, and fluoxetine >60 mg/day, combined with exposure and response prevention therapy. Patients were divided into three dosing groups: sertraline equivalent dose (SED) ≤ 200 mg/day (n = 26, 24.7%), 201-400 mg/day (n = 51, 48.5%) and 401-650 mg/day (n = 28, 26.6%). Safety and tolerability were assessed with an electrocardiogram, blood biochemistry, complete blood count, and side-effects monitoring. RESULTS: SED ranged from 100 to 650 mg/day and the mean duration of OLHD-SRI treatment was 20.8 months. The most common side-effects reported were sexual dysfunction (n = 36, 34%), weight gain (n = 28, 27%), sedation (n = 27, 26%), hyperhidrosis (n = 20, 19%), and tremor (n = 11, 10%). Abnormal ECG was documented in one patient, and another patient experienced a first-time seizure, whereas elevated liver enzymes were seen in 4.8% of the sample (n = 5). None of the patients had serotonin syndrome or drug-induced liver injury. Side-effects did not differ among the three dosing groups. CONCLUSION: OLHD-SRIs appear to be safe and well tolerated in OCD patients in SED ≤ 650 mg/day doses and the side-effects did not differ between the three dosing groups.