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Biomolecules Jun 2024Induced pluripotent stem cell (iPSC) based neuronal differentiation is valuable for studying neuropsychiatric disorders and pharmacological mechanisms at the cellular...
BACKGROUND
Induced pluripotent stem cell (iPSC) based neuronal differentiation is valuable for studying neuropsychiatric disorders and pharmacological mechanisms at the cellular level. We aimed to examine the effects of typical and atypical antipsychotics on human iPSC-derived neural progenitor cells (NPCs).
METHODS
Proliferation and neurite outgrowth were measured by live cell imaging, and gene expression levels related to neuronal identity were analyzed by RT-QPCR and immunocytochemistry during differentiation into hippocampal dentate gyrus granule cells following treatment of low- and high-dose antipsychotics (haloperidol, olanzapine, and risperidone).
RESULTS
Antipsychotics did not modify the growth properties of NPCs after 3 days of treatment. However, the characteristics of neurite outgrowth changed significantly in response to haloperidol and olanzapine. After three weeks of differentiation, mRNA expression levels of the selected neuronal markers increased (except for MAP2), while antipsychotics caused only subtle changes. Additionally, we found no changes in MAP2 or GFAP protein expression levels as a result of antipsychotic treatment.
CONCLUSIONS
Altogether, antipsychotic medications promoted neurogenesis in vitro by influencing neurite outgrowth rather than changing cell survival or gene expression. This study provides insights into the effects of antipsychotics on neuronal differentiation and highlights the importance of considering neurite outgrowth as a potential target of action.
Topics: Humans; Olanzapine; Risperidone; Neurogenesis; Hippocampus; Haloperidol; Antipsychotic Agents; Induced Pluripotent Stem Cells; Neural Stem Cells; Cell Differentiation; Cell Proliferation; Cells, Cultured; Neuronal Outgrowth
PubMed: 38927091
DOI: 10.3390/biom14060688 -
British Journal of Clinical Pharmacology Jun 2024Serotonin syndrome (toxicity), resulting from an excessive accumulation of serotonin in the central nervous system, it can occur due to various factors such as the... (Review)
Review
Serotonin syndrome (toxicity), resulting from an excessive accumulation of serotonin in the central nervous system, it can occur due to various factors such as the initiation of medication, overdose or drug interactions. Diagnosing serotonin toxicity presents challenges as there are no definitive criteria. This review delves into the pathophysiology, incidence, clinical assessment and management of serotonin toxicity, stressing the significance of promptly recognizing and managing severe cases. Diagnosis relies primarily relies on clinical assessment due to the absence of specific laboratory tests. The Hunter Serotonin Toxicity criteria are commonly utilized but have only been validated in the overdose setting. Assessing the severity of toxicity is crucial for guiding management decisions. Supportive care, discontinuation of causative agents and symptomatic treatment are prioritized in management. Mild toxicity often requires withdrawal or reduction of the serotonergic agent, while more severe toxicity requires more aggressive resuscitative and supportive care. Severe serotonin toxicity characterized by hyperthermia and rigidity requires aggressive supportive measures, including benzodiazepines, intubation, paralysis and active cooling. Animal studies suggest potential benefits of 5-HT2A receptor antagonists in preventing hyperthermia and fatalities, but only at high doses. Their clinical effectiveness remains uncertain, and evidence is predominately from case series and case reports. Although commonly used, serotonin antagonists like cyproheptadine lack conclusive evidence of efficacy. Other serotonin antagonists such as chlorpromazine and olanzapine have been explored but evidence is limited to case reports. Hence, the cornerstone of treating severe cases does not lie in 'antidote' administration or even diagnosis but in effective early resuscitative and supportive care.
PubMed: 38926083
DOI: 10.1111/bcp.16152 -
Journal of Biosciences 2024Noradrenaline (NA) and serotonin (5-HT) induce nociception and antinociception. This antagonistic effect can be explained by the dose and type of activated receptors. We...
Noradrenaline (NA) and serotonin (5-HT) induce nociception and antinociception. This antagonistic effect can be explained by the dose and type of activated receptors. We investigated the existence of synergism between the noradrenergic and serotonergic systems during peripheral antinociception. The paw pressure test was performed in mice that had increased sensitivity by intraplantar injection of prostaglandin E (PGE). Noradrenaline (80 ng) administered intraplantarly induced an antinociceptive effect, that was reversed by the administration of selective antagonists of serotoninergic receptors 5-HT isamoltan, 5-HT BRL15572, 5-HT ketanserin, 5-HT ondansetron, but not by selective receptor antagonist 5-HT SB-269970. The administration of escitalopram, a serotonin reuptake inhibitor, potentiated the antinociceptive effect at a submaximal dose of NA. These results, indicate the existence of synergism between the noradrenergic and serotonergic systems in peripheral antinociception in mice.
Topics: Animals; Mice; Norepinephrine; Serotonin; Serotonin Antagonists; Male; Receptors, Serotonin; Dinoprostone; Citalopram; Nociception; Analgesics; Ondansetron; Ketanserin; Pain; Selective Serotonin Reuptake Inhibitors
PubMed: 38920106
DOI: No ID Found -
Frontiers in Psychiatry 2024Abuse or misuse of tobacco, e-cigarettes, or antidepressants may have serious clinical consequences during adolescence, a sensitive period during brain development when...
INTRODUCTION
Abuse or misuse of tobacco, e-cigarettes, or antidepressants may have serious clinical consequences during adolescence, a sensitive period during brain development when the distinct neurobiology of adolescent serotonin (5-HT) and dopamine (DA) systems create unique behavioral vulnerabilities to drugs of abuse.
METHODS
Using a pharmacological approach, we modeled the behavioral and neurochemical effects of subchronic (4-day) nicotine (60µg/kg, i.v.) or fluoxetine (1mg/kg, i.v.) exposure in adolescent and adult male rats.
RESULTS
Nicotine and fluoxetine significantly enhance quinpirole-induced locomotor activity and initial cocaine self-administration in adolescents, but not adults. These effects were blocked by serotonin 5-HT receptor antagonists, WAY-100,635 (100 µg/kg, i.v.) or S-15535 (300 µg/kg, i.v.). Neurochemical and anatomical autoradiographic analysis of 8-OH-DPAT-stimulated [S]GTPγS reveal that prior exposure to nicotine and fluoxetine results in both overlapping and distinct effects on regional 5-HT1A receptor activity. Both fluoxetine and nicotine enhance adolescent 5-HT1A receptor activity in the primary motor cortex (M1), whereas fluoxetine alone targets prefrontal cortical neurocircuitry and nicotine alone targets the amygdala.
DISCUSSION
Given their different pharmacological profiles, comparison between WAY-100,635 and S-15535 indicates that postsynaptic 5-HT receptors mediate the behavioral effects of prior nicotine and fluoxetine exposure. In addition, within the adolescent M1, maladaptive changes in 5-HT signaling and 5-HT activity after nicotine or fluoxetine exposure may potentiate hyper-responsiveness to dopaminergic drugs and prime adolescent vulnerability for future substance abuse.
PubMed: 38919632
DOI: 10.3389/fpsyt.2024.1380123 -
PloS One 2024The aim of this study was to evaluate the impact of intravenous palonosetron compared to ondansetron on hypotension induced by spinal anesthesia in women undergoing... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The aim of this study was to evaluate the impact of intravenous palonosetron compared to ondansetron on hypotension induced by spinal anesthesia in women undergoing cesarean section.
METHODS
Fifty-four women scheduled for elective cesarean section were, randomly allocated to ondansetron group (n = 27) or palonosetron group (n = 27). Ten minutes prior to the administration of spinal anesthesia, participants received an intravenous injection of either ondansetron or palonosetron. A prophylactic phenylephrine infusion was initiated immediately following the intrathecal administration of bupivacaine and fentanyl. The infusion rate was titrated to maintain adequate blood pressure until the time of fetal delivery. The primary outcome was total dose of phenylephrine administered. The secondary outcomes were nausea or vomiting, the need for rescue antiemetics, hypotension, bradycardia, and shivering. Complete response rate, defined as the absence of postoperative nausea and vomiting and no need for additional antiemetics, were assessed for up to 24 hours post-surgery.
RESULTS
No significant differences were observed in the total dose of phenylephrine used between the ondansetron and palonosetron groups (387.5 μg [interquartile range, 291.3-507.8 μg versus 428.0 μg [interquartile range, 305.0-507.0 μg], P = 0.42). Complete response rates also showed no significant differences between the groups both within two hours post-spinal anesthesia (88.9% in the ondansetron group versus 100% in the palonosetron group; P = 0.24) and at 24 hours post-surgery (81.5% in the ondansetron group versus 88.8% in the palonosetron group; P = 0.7). In addition, there was no difference in other secondary outcomes.
CONCLUSION
Prophylactic administration of palonosetron did not demonstrate a superior effect over ondansetron in mitigating hemodynamic changes or reducing phenylephrine requirements in patients undergoing spinal anesthesia with bupivacaine and fentanyl for cesarean section.
Topics: Humans; Female; Anesthesia, Spinal; Cesarean Section; Palonosetron; Adult; Hypotension; Pregnancy; Ondansetron; Antiemetics; Postoperative Nausea and Vomiting; Phenylephrine; Anesthesia, Obstetrical
PubMed: 38917195
DOI: 10.1371/journal.pone.0305913 -
Psychopharmacology Jun 2024The phenylalkylamine hallucinogen (-)-2,5-dimethoxy-4-methylamphetamine (DOM) exhibits an inverted U-shaped dose-response curve for both head twitch response (HTR) and...
RATIONALE
The phenylalkylamine hallucinogen (-)-2,5-dimethoxy-4-methylamphetamine (DOM) exhibits an inverted U-shaped dose-response curve for both head twitch response (HTR) and locomotor activity in mice. Accumulated studies suggest that HTR and locomotor hyperactivity induced by DOM are mainly caused by the activation of serotonin 5-hydroxytryptamine 2 A receptor (5-HT receptor). However, the mechanisms underlying the biphasic dose response of HTR and locomotor activity induced by DOM, particularly at high doses, remain unclear.
OBJECTIVES
The primary objective of this study is to investigate the modulation of 5-HT receptors in HTR and locomotor activity, while also exploring the potential receptor mechanisms underlying the biphasic dose response of DOM.
METHODS
In this study, we employed pharmacological methods to identify the specific 5-HT receptor subtypes responsible for mediating the biphasic dose-response effects of DOM on HTR and locomotor activity in C57BL/6J mice.
RESULTS
The 5-HT receptor selective antagonist (R)-[2,3-di(methoxy)phenyl]-[1-[2-(4-fluorophenyl)ethyl]piperidin-4-yl]methanol (M100907) (500 µg/kg, i.p.) fully blocked the HTR at every dose of DOM (0.615-10 mg/kg, i.p.) in C57BL/6J mice. M100907 (50 µg/kg, i.p.) decreased the locomotor hyperactivity induced by a low dose of DOM (0.625, 1.25 mg/kg, i.p.), but had no effect on the locomotor hypoactivity induced by a high dose of DOM (10 mg/kg) in C57BL/6J mice. The 5-HT antagonist 6-chloro-5-methyl-1-[(2-[2-methylpyrid-3yloxy]pyrid-5yl)carbamoyl]indoline (SB242084) (0.3, 1 mg/kg, i.p.) reduced the HTR induced by a dose of 2.5 mg/kg DOM, but did not affect the response to other doses. SB242084 (1 mg/kg, i.p.) significantly increased the locomotor activity induced by DOM (0.615-10 mg/kg, i.p.) in mice. The 5-HT antagonist N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]N-(2-pyridinyl) cyclohexane carboxamide maleate (WAY100635) (1 mg/kg, i.p.) increased both HTR and locomotor activity induced by DOM in mice. The 5-HT agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) (1 mg/kg, i.p.) significantly reduced both the HTR and locomotor activity induced by DOM in mice. Additionally, pretreatment with the Gα inhibitor PTX (0.25 µg/mouse, i.c.v.) enhanced the HTR induced by DOM and attenuated the effect of DOM on locomotor activity in mice.
CONCLUSIONS
Receptor subtypes 5-HT and 5-HT are implicated in the inverted U-shaped dose-response curves of HTR and locomotor activity induced by DOM in mice. The biphasic dose-response function of HTR and locomotor activity induced by DOM has different mechanisms in mice.
PubMed: 38916640
DOI: 10.1007/s00213-024-06635-4 -
ELife Jun 2024The serotonin-gated ion channel (5-HTR) mediates excitatory neuronal communication in the gut and the brain. It is the target for setrons, a class of competitive...
The serotonin-gated ion channel (5-HTR) mediates excitatory neuronal communication in the gut and the brain. It is the target for setrons, a class of competitive antagonists widely used as antiemetics, and is involved in several neurological diseases. Cryo-electron microscopy (cryo-EM) of the 5-HTR in complex with serotonin or setrons revealed that the protein has access to a wide conformational landscape. However, assigning known high-resolution structures to actual states contributing to the physiological response remains a challenge. In the present study, we used voltage-clamp fluorometry (VCF) to measure simultaneously, for 5-HTR expressed at a cell membrane, conformational changes by fluorescence and channel opening by electrophysiology. Four positions identified by mutational screening report motions around and outside the serotonin-binding site through incorporation of cysteine-tethered rhodamine dyes with or without a nearby quenching tryptophan. VCF recordings show that the 5-HTR has access to four families of conformations endowed with distinct fluorescence signatures: 'resting-like' without ligand, 'inhibited-like' with setrons, 'pre-active-like' with partial agonists, and 'active-like' (open channel) with partial and strong agonists. Data are remarkably consistent with cryo-EM structures, the fluorescence partners matching respectively apo, setron-bound, 5-HT bound-closed, and 5-HT-bound-open conformations. Data show that strong agonists promote a concerted motion of all fluorescently labeled sensors during activation, while partial agonists, especially when loss-of-function mutations are engineered, stabilize both active and pre-active conformations. In conclusion, VCF, though the monitoring of electrophysiologically silent conformational changes, illuminates allosteric mechanisms contributing to signal transduction and their differential regulation by important classes of physiological and clinical effectors.
Topics: Receptors, Serotonin, 5-HT3; Fluorometry; Humans; Patch-Clamp Techniques; Protein Conformation; Serotonin; Cryoelectron Microscopy; HEK293 Cells; Binding Sites; Ion Channel Gating
PubMed: 38913422
DOI: 10.7554/eLife.93174 -
Rivista Di Psichiatria 2024To investigate the effects of electroacupuncture combined with paliperidone palmitate long-acting injection (PP-LAI) on withdrawal symptoms and neurotransmitters in... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To investigate the effects of electroacupuncture combined with paliperidone palmitate long-acting injection (PP-LAI) on withdrawal symptoms and neurotransmitters in methamphetamine (MA) addicts.
MATERIALS AND METHODS
A total of 109 methamphetamine addicts, who were treated in the hospital from October 2021 to October 2022, were selected. According to the random number table, the patients were divided into the study group (n=54) and the control group (n=55), in which the control group was treated with PP-LAI and the study group was treated with electroacupuncture on the basis of the control group; the methamphetamine withdrawal symptom score scale was used to assess the therapeutic effect before treatment and within 12 months after treatment; the changes of brain neurotransmitters dopamine, γ-aminobutyric acid, serotonin, acetylcholine values were compared between the two groups.
RESULTS
1) There was no statistical difference in MA withdrawal symptom scores between the two groups before treatment (p>0.05); 2) MA withdrawal symptom scores have a statistically significant difference between the study group and the control group after 3 and 6 months of treatment; 3) dopamine levels in the study group were significantly higher than those in the control group after 6 months of completion of treatment, and γ-aminobutyric acid values and 5- serotonin values in the study group were significantly lower than those in the control group (p<0.05).
CONCLUSIONS
Electroacupuncture combined with PP-LAI can partially improve the withdrawal symptoms and anxiety of methamphetamine addicts. This is a potential treatment for preventing relapse of withdrawal symptoms.
Topics: Humans; Paliperidone Palmitate; Substance Withdrawal Syndrome; Methamphetamine; Male; Adult; Electroacupuncture; Amphetamine-Related Disorders; Female; Neurotransmitter Agents; Combined Modality Therapy; Delayed-Action Preparations; Dopamine; Serotonin; gamma-Aminobutyric Acid; Middle Aged; Treatment Outcome; Antipsychotic Agents
PubMed: 38912759
DOI: 10.1708/4288.42698 -
Scientific Reports Jun 2024Relationship between depressive disorder and autonomic nervous system has been already discussed. Reduced emotional regulation is supposed to be associated with...
Relationship between depressive disorder and autonomic nervous system has been already discussed. Reduced emotional regulation is supposed to be associated with prefrontal hypofunction and subcortical hyperactivity. The aim of this study was to determine the effect of vortioxetine on heart rate variability (HRV), a parameter of cardiac autonomic regulation, in depressed hospitalized paediatric patients and assess the clinical effectiveness of the drug in this population. We performed repeated polysomnography analyses at admission and after a short treatment in hospital (15.2 days on average) and measured various HRV parameters (RRi, pNN50, RMSSD, LF-HRV, HF-HRV) during wakefulness, N3 and REM sleep stages. Out of 27 study subjects, 67% have improved depression symptoms as well as anxiety and subjective sleep quality after short vortioxetine treatment. We have found a significant decrease in parasympathetic parameters pNN50, RMSSD and HF-HRV during N3 sleep phase, though not exclusively among vortioxetine responders. The anticipated increase in cardiovagal regulation after vortioxetine treatment was not demonstrated in this pilot study, possibly due to the drug's multimodal mechanism and impact on the nucleus tractus solitarii, particularly its antagonism on 5HT-3 receptors. Application of selective drugs could further explain the effect of vortioxetine on HRV in depressed patients.
Topics: Humans; Vortioxetine; Heart Rate; Child; Adolescent; Male; Female; Autonomic Nervous System; Antidepressive Agents; Polysomnography; Depression; Pilot Projects
PubMed: 38910177
DOI: 10.1038/s41598-024-65278-9 -
Trials Jun 2024There are no approved pharmacotherapies for methamphetamine use disorder. Two preliminary phase 2 randomised controlled trials have found mirtazapine, a tetracyclic...
BACKGROUND
There are no approved pharmacotherapies for methamphetamine use disorder. Two preliminary phase 2 randomised controlled trials have found mirtazapine, a tetracyclic antidepressant, to be effective in reducing methamphetamine use. The proposed Tina Trial is the first phase 3 placebo-controlled randomised trial to examine the effectiveness and safety of mirtazapine as an outpatient pharmacotherapy for methamphetamine use disorder.
METHODS
This is a multi-site phase 3 randomised, double-blind, placebo-controlled parallel trial. Participants are randomly allocated (1:1) to receive either mirtazapine (30 mg/day for 12 weeks) or matched placebo, delivered as a take-home medication. The target population is 340 people aged 18-65 years who have moderate to severe methamphetamine use disorder. The trial is being conducted through outpatient alcohol and other drug treatment clinics in Australia. The primary outcome is measured as self-reported days of methamphetamine use in the past 4 weeks at week 12. Secondary outcomes are methamphetamine-negative oral fluid samples, depressive symptoms, sleep quality, HIV risk behaviour and quality of life. Other outcomes include safety (adverse events), tolerability, and health service use. Medication adherence is being monitored using MEMS® Smart Caps fitted to medication bottles.
DISCUSSION
This trial will provide information on the safety and effectiveness of mirtazapine as a pharmacotherapy for methamphetamine use disorder when delivered as an outpatient medication in routine clinical practice. If found to be safe and effective, this trial will support an application for methamphetamine use disorder to be included as a therapeutic indication for the prescription of mirtazapine.
TRIAL REGISTRATION
Australian and New Zealand Clinical Trials Registry ACTRN12622000235707. Registered on February 9, 2022.
Topics: Humans; Mirtazapine; Double-Blind Method; Amphetamine-Related Disorders; Methamphetamine; Adult; Middle Aged; Adolescent; Clinical Trials, Phase III as Topic; Male; Young Adult; Randomized Controlled Trials as Topic; Aged; Female; Treatment Outcome; Multicenter Studies as Topic; Australia; Time Factors; Medication Adherence; Antidepressive Agents, Tricyclic
PubMed: 38907288
DOI: 10.1186/s13063-024-08238-y