Monoamine Transmitters Research Articles

Study on the Improvement of Cognitive Impairment Induced by Scopolamine in Mice by Forsythia suspensa Essential Oil

ABSTRACTIn this study, the mechanism of Forsythia suspensa essential oil (FSEO) on cognitive disorders was investigated based on network pharmacology and animal experiments. The common targets of AD diseases and the main components of FSEO were collected through GeneCards, PubChem, STRING and other databases, and protein–protein interaction (PPI) network maps were established. GO functional enrichment analysis and KEGG pathway enrichment analysis were performed using DAVID and Metascape databases, and the enrichment results were verified using the scopolamine (SCO) cognitive impairment mouse model. The results of network pharmacological analysis showed that FSEO involved 107 potential therapeutic targets, among which MAPK1, MAPK3 and ESR1 were the core targets, which were closely related to the regulatory pathways of MAPK cascade, 5‐hydroxytryptaminergic synapses, dopaminergic synapses and oxidoreductase activity. The results of animal experiments showed that FSEO improved cognitively impaired behaviours, reduced central cholinergic neuron damage and oxidative stress in the mouse brain and increased the content of monoamine transmitters in the mouse brain. Animal experiments further validated the results of the FSEO network pharmacology analysis.

Type A monoamine oxidase; its unique role in mood, behavior and neurodegeneration.

Monoamine oxidase catalyzes oxidative deamination of monoamine transmitters and plays a critical role in the pathogenesis of neuropsychiatric diseases. Monoamine oxidase is classified into type A and B (MAO-A, MAO-B) according to the substrate specificity and sensitivity to inhibitors. The isoenzymes are different proteins coded by different genes localized on the X-chromosome, but they have identical intron-exon organization, similar protein structure and enzymatic mechanism and are considered to be derived from the same ancestral gene. The isoform-specific transcription organization regulates expression and function of MAO-A in response to cellular signaling pathways and environmental factors. MAO-A shows distinct properties and functions: isoform-specified polymorphisms, localization in catecholamine neurons, expression during early embryonic stage, regulation of brain architecture development and mediation of death and survival of neuronal cells. MAO-A is more flexible to genetic and environmental changes than MAO-B. Defective MAO-A expression impairs embryonic brain development and causes adult abnormal mood and behavior, as shown by human male cases with MAO-A deletion. This paper presents the regulation of brain MAO-A expression epigenetically by interaction between genetic and environmental factors. Association of aberrant MAO-A expression and activity with aggression, asocial behaviors, depressive disorders, and neurodegenerative diseases is discussed. Novel therapeutic strategy for psychiatric diseases by intervention to the regulation of MAO-A expression and activity is proposed.

Tetrabenazine, a vesicular monoamine transporter 2 inhibitor, inhibits vesicular storage capacity and release of monoamine transmitters in mouse brain tissue.

Tetrabenazine (TBZ), used for treating hyperkinetic disorders, inhibits vesicular monoamine transporter-2 (VMAT-2), which sequesters monoamines into vesicles for exocytosis. However, our knowledge of the effect of TBZ on monoaminergic transmission is limited. Herein, we provide neurochemical evidence regarding the effect of VMAT-2 inhibition on vesicular neurotransmitter release from the prefrontal cortex (PFC) and striatum (STR) (brain regions involved in characteristic TBZ treatment side effects). The interaction between TBZ and MDMA was also assessed regarding motor behaviour in mice. Vesicular storage capacity and release of [3H]-noradrenaline ([3H]-NA), [3H]-dopamine ([3H]-DA), [3H]-serotonin ([3H]-5-HT), and [3H]-acetylcholine ([3H]-ACh) was studied in mouse PFC and STR ex vivo slice preparations using electrical field stimulation. Additionally, locomotor activity was assessed in vehicle-treated mice and compared with that of MDMA, TBZ, and co-administered animals (n = 6) using the LABORAS system. TBZ lowered the storage capacity and inhibited the vesicular release of [3H]-NA and [3H]-DA from the PFC, and [3H]-DA and [3H]-5-HT from the STR in a concentration-dependent manner. Unlike vesamicol (vesicular ACh uptake inhibitor), TBZ failed to inhibit the vesicular release of [3H]-ACh from the PFC. When the vesicular storage of the investigated monoamines was inhibited by TBZ in the PFC and STR, MDMA induced the release of transmitters through transporter reversal; MDMA dose dependently increased locomotor activity in vivo. Our observations provide neurochemical evidence explaining the mechanism of VMAT-2 inhibitors in the brain and support the involvement of dopaminergic and noradrenergic transmission in hyperkinetic movement disorders.

Effect of esketamine on serum neurotransmitters in patients with postpartum depression: a randomized controlled trial

BackgroundThe development of postpartum depression has been linked to fluctuations in the levels of neurotransmitters in the human body, such as 5-hydroxytryptamine (5-HT), dopamine (DA), noradrenaline (Norepinephrine, NE), and brain derived neurotrophic factor (BDNF). Research has indicated that the antidepressant effect of esketamine are mediated by monoamine transmitters and neurotrophic factors. Therefore, we postulate that intravenous administration of esketamine in patients with postpartum depression may alter the serum concentrations of these neurotransmitters.MethodsThree hundred fifteen patients with postpartum depression were selected and divided into two groups based on randomized numerical expression: esketamine (E) group (0. 25 mg/kg esketamine) and control (C) group (a same volume of 0.9% saline), all the drugs were pumped for 40 min. After the end of drug pumping, all patients were continuously observed for 2 h. Changes in serum levels of 5-HT, DA, NE, BDNF were recorded before drug administration and on the 3rd day after drug administration. The scores of Edinburgh Postnatal Depression Scale (EPDS) were calculated before drug administration, and on the 3rd day and on the 30th day after drug administration. Dizziness, headache, nausea, vomiting, drowsiness, and feeling of detachment occurred were recorded within 2 h after drug administration.ResultsBefore drug administration, the serum concentrations of 5-HT,DA,BDNF,NE in Group E and Group C were namely (0. 91 ± 0. 19 vs. 0. 98 ± 0. 21, P = 0. 181), (2. 38 ± 0. 35 vs. 2. 32 ± 0. 32, P = 0. 491), (3. 07 ± 0. 89 vs 3. 02 ± 0. 88, P = 0. 828), (39. 79 ± 7. 78 vs 41. 34 ± 10. 03, P = 0. 506). On the third day post-medication, the serum concentrations of 5-HT,DA,BDNF,NE in Group E and Group C were namely (1. 42 ± 0. 35 vs. 0. 96 ± 0. 24, P < 0. 001), (3. 99 ± 0. 17 vs. 2. 41 ± 0. 28, P < 0. 001),(5. 45 ± 0. 81 vs 3. 22 ± 0. 76, P < 0. 001),(44. 36 ± 9. 98 vs 40. 69 ± 11. 75, P = 0. 198). Before medication, the EPDS scores were (16. 15 ± 3. 02 vs 17. 85 ± 3. 89, P = 0. 064). on the third day after medication, the Group E had significantly reduced scores (12. 98 ± 2. 39 vs 16. 73 ± 3. 52, P < 0. 001). On the 30rd day after medication, EPDS scores between the two groups were (16. 34 ± 3. 43 vs 16. 91 ± 4. 02, p = 0. 203). Within 2 h of medication, the rate of adverse events was similar between the two groups.ConclusionsSmall doses of esketamine can increase the serum concentration of 5-HT,DA,BDNF, and in the short term, decrease EPDS scores, and improve postpartum depressive symptoms.Trial registrationRetrospectively registered in the Chinese Clinical Trial Registry (ChiCTR2300078343, 2023/12/05).

Dynamic quantitative monitoring of cerebrospinal fluid monoamine neurotransmitter markers during the modeling process of chronic stress-induced depression in monkeys (Macaca mulatta).

Depression is known as the "mental cold" and is also considered a major cause of disability worldwide. It is estimated that over 300 million people worldwide suffer from severe depression, equivalent to 4.4% of the world's population. The monoamine hypothesis of depression predicts the underlying pathophysiological mechanisms of depression, but in-depth research has failed to find convincing evidence. In this study, we will dynamically and strictly quantitatively monitor the concentration changes of monoamine transmitters in the cerebrospinal fluid (CSF) of macaques, based on our previous work. In the experiment, timed and quantitative collection of CSF samples from macaques was performed and the concentration of monoamine transmitters was determined. The results showed that after 2 months of chronic stress, the concentrations of high vanillin acid (HVA) and 3,4-dihydroxy-phenylacetic acid were significantly higher in the maternal separation (MS) group, whereas there was no significant difference in dopamine and 5-hydroxyindoleacetic acid. This study is the first to observe the long-term dynamic relationship between early adversity, chronic stress, adolescent depression, and CSF monoamine concentrations. The research suggests that MS and chronic stress play an undeniable role in the pathogenesis of depression and that concentrations of HVA and dihydroxyphenylacetic acid are likely to serve as early markers of depressive-like symptoms in macaques.

Tricyclic and tetracyclic antidepressants upregulate VMAT2 activity and rescue disease-causing VMAT2 variants

Vesicular monoamine transporter 2 (VMAT2) is an essential transporter that regulates brain monoamine transmission and is important for mood, cognition, motor activity, and stress regulation. However, VMAT2 remains underexplored as a pharmacological target. In this study, we report that tricyclic and tetracyclic antidepressants acutely inhibit, but persistently upregulate VMAT2 activity by promoting VMAT2 protein maturation. Importantly, the VMAT2 upregulation effect was greater in BE(2)-M17 cells that endogenously express VMAT2 as compared to a heterologous expression system (HEK293). The net sustained effect of tricyclics and tetracyclics is an upregulation of VMAT2 activity, despite their acute inhibitory effect. Furthermore, imipramine and mianserin, two representative compounds, also demonstrated rescue of nine VMAT2 variants that cause Brain Monoamine Vesicular Transport Disease (BMVTD). VMAT2 upregulation could be beneficial for disorders associated with reduced monoamine transmission, including mood disorders and BMVTD, a rare but often fatal condition caused by a lack of functional VMAT2. Our findings provide the first evidence that small molecules can upregulate VMAT2 and have potential therapeutic benefit for various neuropsychiatric conditions.

Effects of SRI-32743, a Novel Quinazoline Structure-Based Compound, on HIV-1 Tat and Cocaine Interaction with Norepinephrine Transporter.

Prolonged exposure to HIV-1 transactivator of transcription (Tat) protein dysregulates monoamine transmission, a physiological change implicated as a key factor in promoting neurocognitive disorders among people living with HIV. We have demonstrated that in vivo expression of Tat in Tat transgenic mice decreases dopamine uptake through both dopamine transporter (DAT) and norepinephrine transporter (NET) in the prefrontal cortex. Further, our novel allosteric inhibitor of monoamine transporters, SRI-32743, has been shown to attenuate Tat-inhibited dopamine transport through DAT and alleviates Tat-potentiated cognitive impairments. The current study reports the pharmacological profiles of SRI-32743 in basal and Tat-induced inhibition of human NET (hNET) function. SRI-32743 exhibited less affinity for hNET binding than desipramine, a classical NET inhibitor, but displayed similar potency for inhibiting hDAT and hNET activity. SRI-32743 concentration-dependently increased hNET affinity for [3H]DA uptake but preserved the Vmax of dopamine transport. SRI-32743 slowed the cocaine-mediated dissociation of [3H]Nisoxetine binding and reduced both [3H]DA and [3H]MPP+ efflux but did not affect d-amphetamine-mediated [3H]DA release through hNET. Finally, we determined that SRI-32743 attenuated a recombinant Tat1-86-induced decrease in [3H]DA uptake via hNET. Our findings demonstrated that SRI-32743 allosterically disrupts the recombinant Tat1-86-hNET interaction, suggesting a potential treatment for HIV-infected individuals with concurrent cocaine abuse.

Blood oxygen regulation via P2Y12R expressed in the carotid body

BackgroundPeripheral blood oxygen monitoring via chemoreceptors in the carotid body (CB) is an integral function of the autonomic cardiorespiratory regulation. The presence of the purinergic P2Y12 receptor (P2Y12R) has been implicated in CB; however, the exact role of the receptor in O2 sensing and signal transduction is unknown.MethodsThe presence of P2Y12R was established by immunoblotting, RT qPCR and immunohistochemistry. Primary glomus cells were used to assess P2Y12R function during hypoxia and hypercapnia, where monoamines were measured by HPLC; calcium signal was recorded utilizing OGB-1 and N-STORM Super-Resolution System. Ingravescent hypoxia model was tested in anaesthetized mice of mixed gender and cardiorespiratory parameters were recorded in control and receptor-deficient or drug-treated experimental animals.ResultsInitially, the expression of P2Y12R in adult murine CB was confirmed. Hypoxia induced a P2Y12R-dependent release of monoamine transmitters from isolated CB cells. Receptor activation with the endogenous ligand ADP promoted release of neurotransmitters under normoxic conditions, while blockade disrupted the amplitude and duration of the intracellular calcium concentration. In anaesthetised mice, blockade of P2Y12R expressed in the CB abrogated the initiation of compensatory cardiorespiratory changes in hypoxic environment, while centrally inhibited receptors (i.e. microglial receptors) or receptor-deficiency induced by platelet depletion had limited influence on the physiological adjustment to hypoxia.ConclusionsPeripheral P2Y12R inhibition interfere with the complex mechanisms of acute oxygen sensing by influencing the calcium signalling and the release of neurotransmitter molecules to evoke compensatory response to hypoxia. Prospectively, the irreversible blockade of glomic receptors by anti-platelet drugs targeting P2Y12Rs, propose a potential, formerly unrecognized side-effect to anti-platelet medications in patients with pulmonary morbidities.

Broiler Heart Muscle Monoaminergic Receptors Alteration in Response to Chronic Heat Stress: Based on Transcription Analysis.

Chronic heat stress affects numerous physiological and behavioral mechanisms. Epigenetic changes following prolonged cyclic heat stress, creating new opportunities for molecular biology research. One of these changes involves monoamines, such as serotonin, epinephrine, norepinephrine, dopamine, and their transmission. Broiler chickens are highly susceptible to heat stress, and their hearts become insufficient during the growth phase, leading to hypertrophy of the left heart. RNA-seq data were obtained from NCBI with accession number SRP082125. The expression level of genes was determined with DESeq2 packages. Gene Ontology qualification, including biological processes, cellular components, and molecular role (MF), was performed from the Gene Ontology Resource. Cyclic heat stress in broilers significantly altered monoamine receptor expression. Twenty-nine genes of the monoamine pathway changed their expression in the left heart. Significant downregulation of expression was statistically associated with the ADRB1, HTR2A, and PNMT genes and upregulation of the MAOA gene (P<0.01). STRING database was used to construct the protein-protein interaction network; based on network analysis, the HTR2C, HTR2A, and HTR5A genes were identified as the major nodal genes in the network followed by MAOA, DRD2, DRD5, HTR1B, DRD1, DRD3, and HTR2B genes occupying the second important place in the network module. In conclusion, heat stress treatment prevented cardiac hypertrophy and altered the expression of monoamine genes. This would imply that monoamine transmission plays an important role in the development of cardiac hypertrophy, and that cyclic-chronic heat treatment modulates the cardiac monoaminergic system. These molecular biomarkers could be useful for screening, diagnosis, and treatment of cardiac hypertrophy.

A Comparison of PKD2L1-Expressing Cerebrospinal Fluid Contacting Neurons in Spinal Cords of Rodents, Carnivores, and Primates.

Cerebrospinal fluid contacting neurons (CSF-cNs) are a specific type of neurons located around the ventricles in the brain and the central canal in the spinal cord and have been demonstrated to be intrinsic sensory neurons in the central nervous system. One of the important channels responsible for the sensory function is the polycystic kidney disease 2-like 1 (PKD2L1) channel. Most of the studies concerning the distribution and function of the PKD2L1-expressing CSF-cNs in the spinal cord have previously been performed in non-mammalian vertebrates. In the present study immunohistochemistry was performed to determine the distribution of PKD2L1-immunoreactive (IR) CSF-cNs in the spinal cords of four mammalian species: mouse, rat, cat, and macaque monkey. Here, we found that PKD2L1-expressing CSF-cNs were present at all levels of the spinal cord in these animal species. Although the distribution pattern was similar across these species, differences existed. Mice and rats presented a clear PKD2L1-IR cell body labeling, whereas in cats and macaques the PKD2L1-IR cell bodies were more weakly labeled. Ectopic PKD2L1-IR neurons away from the ependymal layer were observed in all the animal species although the abundance and the detailed locations varied. The apical dendritic protrusions with ciliated fibers were clearly seen in the lumen of the central canal in all the animal species, but the sizes of protrusion bulbs were different among the species. PKD2L1-IR cell bodies/dendrites were co-expressed with doublecortin, MAP2 (microtubule-associated protein 2), and aromatic L-amino acid decarboxylase, but not with NeuN (neuronal nuclear protein), indicating their immature properties and ability to synthesize monoamine transmitters. In addition, in situ hybridization performed in rats revealed PKD2L1 mRNA expression in the cells around the central canal. Our results indicate that the intrinsic sensory neurons are conserved across non-mammalian and mammalian vertebrates. The similar morphology of the dendritic bulbs with ciliated fibers (probably representing stereocilia and kinocilia) protruding into the central canal across different animal species supports the notion that PKD2L1 is a chemo- and mechanical sensory channel that responds to mechanical stimulations and maintains homeostasis of the spinal cord. However, the differences of PKD2L1 distribution and expression between the species suggest that PKD2L1-expressing neurons may receive and process sensory signals differently in different animal species.

Antidepressant effect of Perilla frutescens essential oil through monoamine neurotransmitters and BDNF/TrkB signal pathway

Ethnopharmacological relevanceTraditional Chinese medicine posits that affect-mind ill-being is the primary cause of depression, with Qi movement stagnation as its pathogenesis. As such, clinical treatment for depression should prioritize regulating Qi and relieving depressive symptoms. The pharmacological properties of traditional Chinese medicine indicate that Perilla frutescens may have potential therapeutic effects on depression and other neuropsychiatric diseases due to its ability to regulate Qi and alleviate depressive symptoms. Although previous studies have reported the antidepressant effects of Perilla frutescens, the mechanism underlying PFEO inhalation-mediated antidepressant effect remains unclear. Aim of the studyThe aim of this investigation is to elucidate the antidepressant mechanisms of PFEO by examining its effects on monoamine neurotransmitters and the BDNF/TrkB signaling pathway. Materials and methodsThe CUMS rat model of depression was established, and the depressive state of the animals was assessed through sucrose preference and forced swim tests. ELISA assays were conducted to determine monoamine neurotransmitter levels in the hippocampus and cerebral cortex of rats. Immunohistochemistry, western blotting, and RT-PCR experiments were employed to investigate the BDNF/TrkB signaling pathway's regulation of depression via PFEO inhalation. ResultsIt has been observed that inhalation administration of PFEO can significantly enhance the preference for sugar water in CUMS rats and reduce their immobility time during forced swimming. Additionally, there was an increase in the levels of monoamine transmitters in both the hippocampus and cerebral cortex of these rats. Furthermore, there was an upregulation in the expression levels of BDNF and TrkB positive cells as well as BDNF and TrkB proteins within both regions, along with increased BDNF mRNA and TrkB mRNA expression levels. ConclusionThe antidepressant effect of PFEO via inhalation administration is speculated to be mediated through the monoamine neurotransmitters and BDNF/TrkB signaling pathway.

The role of NMDA glutamate receptors in the lateral habenula on morphine-induced conditioned place preference in rats.

The lateral habenula (LHb) has received special attention due to its role in modulating motivated behavior, stress response, and rewarding and aversive stimuli through monoamine transmission. In the present study, the involvement of the N-methyl-d-aspartate (NMDA) receptors of the LHb in the expression and acquisition phases of morphine-induced conditioned place preference (CPP) was studied in male rats. Bilateral injections of agonist/antagonist (MK-801) of NMDA receptor were performed during the conditioning sessions of the acquisition phase. In other separate groups, drugs were also injected into the LHb before the test session during the expression phase of CPP. A 5-day CPP bias paradigm was used to study the effect of injections of NMDA and MK-801 into the LHb on morphine reward-related behavior. Different doses of NMDA plus morphine reduced the CPP score during the acquisition phase, whereas MK-801 significantly increased conditioning scores during the acquisition phase of CPP. The injection of agonists and antagonists of NMDA receptors in LHb had no significant effect on CPP scores and locomotion during the expression phase of CPP, whereas the motor activity in the acquisition phase was affected by the drugs. The reduction effect of NMDA on the CPP scores during the acquisition phase was blocked by pretreatment with MK-801. Our findings also suggest that NMDA receptors in the LHb may be involved in the acquisition phase of morphine-induced CPP.

Safety of the Concurrent Administration of Serotonergic Antidepressants and Ozanimod in Patients With Relapsing Multiple Sclerosis (P7-3.013)

Safety of the Concurrent Administration of Serotonergic Antidepressants and Ozanimod in Patients With Relapsing Multiple Sclerosis (P7-3.013)

Broiler Heart Muscle Monoaminergic Receptors Alteration in Response to Chronic Heat Stress: Based on Transcription Analysis

Chronic heat stress affects numerous physiological and behavioral mechanisms. Epigenetic changes following prolonged cyclic heat stress, creating new opportunities for molecular biology research. One of these changes involves monoamines, such as serotonin, epinephrine, norepinephrine, dopamine, and their transmission. Broiler chickens are highly susceptible to heat stress, and their hearts become insufficient during the growth phase, leading to hypertrophy of the left heart. RNA-seq data were obtained from NCBI with accession number SRP082125. The expression level of genes was determined with DESeq2 packages. Gene Ontology qualification, including biological processes, cellular components, and molecular role (MF), was performed from the Gene Ontology Resource. Cyclic heat stress in broilers significantly altered monoamine receptor expression. Twenty-nine genes of the monoamine pathway changed their expression in the left heart. Significant downregulation of expression was statistically associated with the ADRB1, HTR2A, and PNMT genes and upregulation of the MAOA gene (P&lt;0.01). STRING database was used to construct the protein-protein interaction network; based on network analysis, the HTR2C, HTR2A, and HTR5A genes were identified as the major nodal genes in the network followed by MAOA, DRD2, DRD5, HTR1B, DRD1, DRD3, and HTR2B genes occupying the second important place in the network module. In conclusion, heat stress treatment prevented cardiac hypertrophy and altered the expression of monoamine genes. This would imply that monoamine transmission plays an important role in the development of cardiac hypertrophy, and that cyclic-chronic heat treatment modulates the cardiac monoaminergic system. These molecular biomarkers could be useful for screening, diagnosis, and treatment of cardiac hypertrophy.

Preclinical Pharmacology of Solriamfetol: Potential Mechanisms for Wake Promotion

AbstractIntroductionSolriamfetol is a wake-promoting agent (WPA) approved for the treatment of excessive daytime sleepiness associated with narcolepsy and obstructive sleep apnea. The wake-promoting mechanism of solriamfetol may result from dopamine and norepinephrine reuptake inhibition. Preclinical pharmacology studies were conducted to further elucidate the molecular targets activated by solriamfetol and compare them to that of known WPAs and traditional stimulants.MethodsIn vitro binding and functional studies were conducted in a panel of cell lines or membrane preparations expressing transmembrane receptors and monoamine transporters to measure the activity of solriamfetol, comparator WPAs, and traditional stimulants. Electrophysiology studies were conducted in slice preparations from mouse ventral tegmental area (VTA). Studies to measure locomotor activity and wake-promoting effects were conducted in mice.ResultsIn vitro functional studies showed agonist activity of solriamfetol at human, mouse, and rat TAAR1 receptors. hTAAR1 EC50 values (10–16 μM) were within the clinically observed therapeutic solriamfetol plasma concentration range and overlapped with the observed DAT/NET inhibitory potencies of solriamfetol in vitro. TAAR1 agonist activity was unique to solriamfetol; neither the WPA modafinil nor the DAT/NET inhibitor bupropion had TAAR1 agonist activity. Solriamfetol (1–10 μM) dose-dependently inhibited the firing frequency of dopaminergic VTA neurons in mouse brain slices, similar to known TAAR1 agonists; however, these effects were inhibited by a D2 antagonist, suggesting a DAT-mediated effect. Unlike traditional stimulants, solriamfetol did not increase locomotor activity in naive mice, but inhibited the increase in locomotor activity in DAT knockout mice.ConclusionsPreclinical studies have identified agonist activity at the TAAR1 receptor and, possibly, lower potency agonist activity at 5-HT1A receptors as potential pharmacological targets for solriamfetol, in addition to its activity as a DAT/NET inhibitor. Given the current understanding of TAAR1 agonists as modulators of monoamine transmission with potential wake-promoting effects in multiple preclinical species, agonist activity at the hTAAR1 receptor may represent an additional pharmacological target underlying the wake-promoting effects for solriamfetol, in addition to its DNRI activity.FundingAxsome Therapeutics, Jazz Pharmaceuticals

Inhibitory effect of atomoxetine on Nav1.2 voltage-gated sodium channel currents.

Atomoxetine (ATX), a norepinephrine reuptake inhibitor (NRI), is used to attenuate the symptoms of Attention Deficit/Hyperactivity Disorder (AD/HD) by increasing neurotransmitter concentrations at the synaptic cleft. Although Nav1.2 voltage-gated sodium channels (VGSCs) are thought to play a role in monoamine transmitter release in the synaptic junction, it is unclear how atomoxetine affects Nav1.2 VGSCs. In this study, we investigated the effect of ATX on Nav1.2 VGSC-transfected HEK293 cells with the whole-patch clamp technique. Nav1.2 VGSC current decreased by 51.15 ± 12.75% under treatment with 50µM ATX in the resting state (holding membrane potential at - 80mV). The IC50 of ATX against Nav1.2 VGSC current was 45.57µM. The activation/inactivation curve of Nav1.2 VGSC currents was shifted toward hyperpolarization by 50µM ATX. In addition, the inhibitory effect of ATX increased with membrane depolarization (holding membrane potential at - 50mV) and its IC50 was 10.16µM. Moreover, ATX showed the time-dependent interaction in the inactivation state. These findings suggest that ATX interacts with Nav1.2 VGSCs producing the inhibition of current and the modification of kinetic properties in the state-dependent manner.

Acute Suicidal Ideation in the Context of Esketamine Maintenance Therapy

Acute Suicidal Ideation in the Context of Esketamine Maintenance Therapy

Mephedrone – a synthetic derivative of cathinone

Abstract Novel psychoactive substances (NPS) are a very diverse group of recreational drugs that mimic effects of classic drugs of abuse and, at least at the beginning, are not usually prohibited. Representative of this group is mephedrone – a cathinone derivative. It is widely used as a recreational drug, particularly among club guests. Mephedrone`s effects are compared to effects of cocaine and MDMA but are more short-lived and include: psychostimulation, enhanced empathy, reduced feeling of tiredness, euphoria, hallucinations. This drug also exerts adverse effects, such as: anxiety, delusions, paranoia, psychosis, increased body temperature, elevated blood pressure, sleep disturbances. According to surveys performed on mephedrone users, it may be addictive. Those findings confirms a growing number of behavioural and molecular studies on animals. Mephedrone acts mainly via increasing monoamine transmission through increasing release of dopamine, serotonin and noradrenaline into synaptic cleft, inhibiting their re-uptake and reducing their metabolism. However, participation of other transmitters, modulators and pathways are investigated, including glutamate and nitric oxide. Favorable routes of administering mephedrone is intranasal and per os. Moreover, most often drug users use it in a binge way, e.g. taking repeated doses of a drug in a short period of time. According to animal studies, this pattern of mephedrone use leaves more neural injuries than taking it regularly, but in smaller doses. Our aim was to present a short, but essential, overview of the current knowledge on mephedrone, focusing on its effects, mechanism of action, animal studies evaluating its influence on the brain structures, toxicity and pharmacokinetics.

Lipopolysaccharide induced neuroprotective effects of bacterial protease against Alzheimer's disease in male Wistar albino rats

Alzheimer's disease (AD) is a highly severe neurodegenerative condition that affects the hippocampus and is characterized by memory loss and dementia. This investigation aims to determine the potential of a bacterial protease enzyme produced by a new mutant strain of bacteria (Bacillus cereus S6-3/UM90) to influence the rat behavioural, biochemical, histological, and immuno-histochemical functions induced by lipopolysaccharides (LPS) experimentally. The administration of LPS exhibited a decline in memory performance via Morris' Water Maze test along with an elevation of IL-6, IL-17, amino acid neurotransmitters, Adenosine monophosphate (AMP), and 8-OHdG, whereas a decrease in ATP (Adenosine Triphosphate), monoamine transmitters, AChE (acetylcholinesterase) and PC (phosphatidylcholine). Additionally, there was a notable increase in GFAP (glial fibrillary acidic protein) and p-Tau protein immuno-expression levels along with obvious histological lesions in the hippocampal CA3 region. Moreover, the administration of protease or Donepezil restored the measured parameters to nearly normal levels and improved the histological architecture of the hippocampus and ameliorated memory impairments. In conclusion, the study provides evidence that the treatment with Bacterial protease can improve the memory and learning impairments of LPS–induced AD and may be used as a promising therapeutic agent to manage AD since it has anti-inflammatory and antioxidant effects.

Midbrain dopamine neurons arbiter OCD-like behavior

The neurobiological understanding of obsessive-compulsive disorder (OCD) includes dysregulated frontostriatal circuitry and altered monoamine transmission. Repetitive stereotyped behavior (e.g., grooming), a featured symptom in OCD, has been proposed to be associated with perturbed dopamine (DA) signaling. However, the precise brain circuits participating in DA's control over this behavioral phenotype remain elusive. Here, we identified that DA neurons in substantia nigra pars compacta (SNc) orchestrate ventromedial striatum (VMS) microcircuits as well as lateral orbitofrontal cortex (lOFC) during self-grooming behavior. SNc-VMS and SNc-lOFC dopaminergic projections modulate grooming behaviors and striatal microcircuit function differentially. Specifically, the activity of the SNc-VMS pathway promotes grooming via D1 receptors, whereas the activity of the SNc-lOFC pathway suppresses grooming via D2 receptors. SNc DA neuron activity thus controls the OCD-like behaviors via both striatal and cortical projections as dual gating. These results support both pharmacological and brain-stimulation treatments for OCD.